Documents published in 2005 : Scipedia

SAFETY AND SECURITY IMPROVEMENT IN PUBLIC TRANSPORTATION BASED ON PUBLIC PERCEPTION IN DEVELOPING COUNTRIES
T. Joewono, H. Kubota

Collection of open articles in transport research (2006). Vol. 2006, 10

Abstract
Public transportation poses a higher risk of safety and security since there happen to be more passengers in one car. The problem becomes worse in developing countries, because of the lack of suitable and integrated approaches. The aim of this research is to explore the perception of safety and security problems on the part of those parties involved in the operation of public transportation. This perception is used as a base to develop an improvement agenda for the particular context of developing countries. The research employs a questionnaire survey to collect the perception data. This paper explains the perception of users and drivers of paratransit as well as that of non-users and civil servants, concerning safety and security of paratransit in the city of Bandung, Indonesia. The rank of importance for each factor is analyzed by applying the factor analysis. Analysis shows that the user is the most important party involved. The understanding and awareness of the user (including the driver) is the most important variable to improve the condition. Three aspects of an improvement agenda are proposed based on the perception data, namely technology, management, and institution. This agenda is clarified by a set of action plans incorporating the responsible parties and a time frame. The action plan is divided into three terms to define a clear goal for each step. The short-term action focuses on the hardware and on preparing further steps, whereas the medium-term action focuses on developing and improving the standard of safety and security. The long-term action focuses on advancing safety and security practices. The effectiveness of this agenda and action plan rests upon a set of assumptions, such as the degree of seriousness from the authoritative institution, fair distribution of information, the availability of reasonable resources, and coordinated and collaborative action from all parties involved to reach the objective. Document type: Article
Abstract
Public transportation poses a higher risk of safety and security since there happen to be more passengers in one car. The problem becomes worse in developing countries, because [...]
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Haulage trucks model with four electric separate wheel drives
R. Setlak

Collection of open articles in transport research (2005). Vol. 2005, 12

Abstract
This article contains a course of work of the construction of a vehicle model that has four electrical motors built into each wheel. During the project two models of a vehicle were constructed (Figs 3,5). A microprocessor based control system has also been designed and built. A vehicle is controlled by a steering unit (Fig 8) which contains a steering wheel with a force feedback system, push buttons, an accelerator and a brake. The connection between a steering unit and a model is realized by interface RSâ€485. The driving motors are dc motors with permanent magnets. Power supply consists of an acid battery located in the vehicle. The vehicle control system is divided into two parts. The first part is built into the vehicle (Fig 7) and operates as a vehicle main control system and the second is built into a steering unit and operates as the main control steering system. First Published Online: 27 Oct 2010 Document type: Article
Abstract
This article contains a course of work of the construction of a vehicle model that has four electrical motors built into each wheel. During the project two models of a vehicle [...]
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Research into occupant's motion in vehicles during crashes
L. Pelenyte-Vyšniauskiene, A. Jurkauskas

Collection of open articles in transport research (2005). Vol. 2005, 11

Abstract
Traffic accidents depend on many factors and circumstances. Important data are registered by taking photos of the accident place, measuring the deformations of vehicles and skidding and sliding traces. Weather conditions, driversâ€™ and pedestrian's actions are also taken into account. However the existing data are far from sufficient to conduct a research into traffic accidents. In such cases mathematical modelling and the application of computer programs are very helpful. This article deals with the processes during the collision of vehicles as well as the occupant's dynamics inside the vehicle. The research studies on what the occupant motion depends and what is the power balance between the occupant and safety means. The article offers a way of evaluating injuries, measuring the occupantsâ€™ acceleration and velocity, taking into account different distances inside the vehicle during an accident. First Published Online: 27 Oct 2010 Document type: Article
Abstract
Traffic accidents depend on many factors and circumstances. Important data are registered by taking photos of the accident place, measuring the deformations of vehicles and [...]
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THE RESEARCH INTO SPEED ABILITY OF FUEL DISPERSION
A. Svistula, A. Eskov, D. Matievsky

Collection of open articles in transport research (2005). Vol. 2005, 10

Abstract
The investigation of the process of carburetion in combustion engines is an actual scientific and practical task. The results of the experimental investigations of the fuel jet flow formed by the nozzle through two section series arranged are shown in the presented article. Front speed and fuel mass speed between optical sections in fuel flow were determined by registered optical density of fuel flow for different pressures. The procedure of the determination of speed abilities of the fuel flow gives the preconditions for creating the bench for the determination of fuel sprayers in the work process of manufacturing with the aim of their division into the groups of oneâ€type parameters. Such approach assumes the usage of manufacturing standard that is the sprayer and the fuel pump with the best ability of injection. First Published Online: 27 Oct 2010 Document type: Article
Abstract
The investigation of the process of carburetion in combustion engines is an actual scientific and practical task. The results of the experimental investigations of the fuel [...]
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Applied Gis software for improving pedestrian & bicycle safety
H. Ziari, M. Khabiri

Collection of open articles in transport research (2005). Vol. 2005, 9

Abstract
People are important in towns. They are the foundation of the social and economic processes that drive the urban system and sustain the urban fabric. While people spend much of their time inside buildings â€ at home, at work, and at play â€ it is the movement of people, whether in vehicles or on foot, that is indicative of the vibrancy of the town. Comfort and safety are important for people movement. The crash data in cities, provinces started with the Traffic Organization of Inner Ministry looking at access management controls on functionally classified streets. Safety is a driving factor in access management and the crash reports are the best indicator of the lack of safe roads. This paper presents the development and findings of crash data from police reports and how they are being used in Geographic Information System (GIS). This tool generates a contour map identifying areas of high crash occurrence determined by crash density and clusters of crashes involving pedestrians or bicyclists. Summary statistics of the selected zones can be generated and displayed in a table or chart form. First Published Online: 27 Oct 2010 Document type: Article
Abstract
People are important in towns. They are the foundation of the social and economic processes that drive the urban system and sustain the urban fabric. While people spend much [...]
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A STUDY ON THE INTRODUCTION OF BUS RAPID TRANSIT SYSTEM IN ASIAN DEVELOPING CITIES
R. Oshima, T. Satiennam, A. Fukuda

Collection of open articles in transport research (2006). Vol. 2006, 7

Abstract
Bus Rapid Transit (BRT) has increasingly become an attractive urban transit alternative in many Asian developing cities due to its cost-effective and flexible implementation. However, it still seems to be difficult to introduce BRT to these cities because almost all of their city structures have been developed under solely a road transport development city plan and weakness of land use control gives rise to many problems, such as urban sprawl, traffic congestion, and air pollution. The purpose of this study was to introduce several strategies to support BRT implementation in Asian developing cities, such as a strategy to appropriately integrate the paratransit system into BRT system as being a feeder along a BRT corridor to supply demand. These proposed strategies were evaluated by applying demand forecasting and emission models to the BRT project plan of Bangkok Metropolitan Administration (BMA) in Thailand. It was demonstrated that the proposed strategies could effectively improve the BRT ridership, traffic conditions, and air pollution emission of the entire system in Bangkok. This study could be further extended to include strategy recommendation if a BRT system were to be introduced to other Asian developing cities. Document type: Article
Abstract
Bus Rapid Transit (BRT) has increasingly become an attractive urban transit alternative in many Asian developing cities due to its cost-effective and flexible implementation. [...]
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Policy Based QoS Architecture in MUSE
A. Foglar, P. Nooren, A. Armengol, G. Rajan

Collection of closed articles in transport research (2006). Vol. 2006, 15

Abstract
This paper presents the architecture and framework for a policy based QoS control in a shared medium type of network such as Ethernet. QoS is achieved by a combination of traffic engineering of bandwidth pipes, priority scheduling of traffic at network nodes and controlled access to the bandwidth pipes in broadband access networks.
Abstract
This paper presents the architecture and framework for a policy based QoS control in a shared medium type of network such as Ethernet. QoS is achieved by a combination of [...]
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Modelling the effects of road traffic safety measures. Accident Analysis & Prevention
M. Lu

Collection of closed articles in transport research (2006). Vol. 2006, 14

Abstract
model is presented for assessing the effects of traffic safety measures, based on a breakdown of the process in underlying components of traffic safety (risk and consequence), and five (speed and conflict related) variables that influence these components, and are influenced by traffic safety measures. The relationships between measures, variables and components are modelled as coefficients. The focus is on probabilities rather than historical statistics, although in practice statistics may be needed to find values for the coefficients. The model may in general contribute to improve insight in the mechanisms between traffic safety measures and their safety effects. More specifically it allows comparative analysis of different types of measures by defining an effectiveness index, based on the coefficients. This index can be used to estimate absolute effects of advanced driver assistance systems (ADAS) related measures from absolute effects of substitutional (in terms of safety effects) infrastructure measures.
Abstract
model is presented for assessing the effects of traffic safety measures, based on a breakdown of the process in underlying components of traffic safety (risk and consequence), [...]
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Towards a modal shift in freight transport? A business logistics analysis of some policy measures
F. Witlox, B. Vernimmen, G. Blauwens, E. Voorde, N. Vandaele

Collection of closed articles in transport research (2006). Vol. 2006, 13

Abstract
This paper analyses the effectiveness of policy measures aimed at triggering a modal shift in the freight transport market. The analysis is based on the inventory‐theoretic framework that studies modal choice from a business logistics viewpoint. The crux of the inventory‐theoretic approach lies in the fact that explicit attention is paid to all costs in the supply chain that are affected by the choice of transport mode. After a brief literature review on the inventory‐theoretic framework, the framework is used to calculate the market shares of different freight transport modes for a hypothetical transport market. In a second step, the impact of some policy measures on the market shares of the transport modes is calculated. By way of illustration, the analysis is applied to the market for container transport from a seaport to its hinterland. It is shown that a combination of certain policy measures can lead to significant modal shifts from road transport to intermodal transport.
Abstract
This paper analyses the effectiveness of policy measures aimed at triggering a modal shift in the freight transport market. The analysis is based on the inventory‐theoretic [...]
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Driver behaviour in motorway car-following transitions and driver support systems
P. Feenstra, A. Horst

Collection of closed articles in transport research (2006). Vol. 2006, 12

Abstract
Co-operative driving with speed adaptation functionality has great potential to improve traffic-throughput, traffic-safety, and environmental-impact on heavily used traffic-infrastructures. A driving-simulator study was performed to investigate the driver behaviour with respect to such driver-support systems (Zero-, Advisory-, Intervention-, and Controlling). This paper describes the results of one specific scenario, a cut-in scenario. The results show a small reaction time, which was smaller than the response-time required for stabilizing the manoeuvre. Subjective measures show that the experienced-effort for the Controlling system was the smallest, that the satisfaction for the Controlling system was the highest and that the usefulness of all systems was positive.
Abstract
Co-operative driving with speed adaptation functionality has great potential to improve traffic-throughput, traffic-safety, and environmental-impact on heavily used traffic-infrastructures. [...]
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Hydraulic Analysis and Direct Design of Multiple Outlets Pipelines Laid on Flat and Sloping Lands
G. Yıldırım

Collection of closed articles in transport research (2006). Vol. 2006, 11

Abstract
WOS: 000242429200004 Adequate hydraulic analysis of a multiple outlets pipelines is very important for the design and evaluation of irrigation systems. In this paper, an analytical direct design procedure for a single multiple outlets pipelines is presented. The proposed equations, taking into consideration the influence of local energy loss, are suitable for designing laterals and manifolds in both trickle and sprinkler irrigation systems, and can be applied for various types of outlet, different flow regimes, and uniform line slope ranges. In this analytical procedure, for any desired uniformity level and given design slope range with remaining known parameters, the pipe diameter and the pipe length can then be directly designed. For any desired uniformity level, the procedure also provides an opportunity to evaluate the influence of local energy loss, as well as the influence of different uniform line slopes on the pipe geometric characteristics (pipe size and length), and on the corresponding hydraulic variables (operating inlet pressure head, downstream end pressure head, and total energy loss). Comparison test with a revised step-by-step numerical method for various slope combinations indicated that the presented methodology produces sufficiently accurate results for various design cases in both trickle and sprinkler lateral design. The methodology is simple, easy to apply, and useful for hydraulic analysis and direct design of a multiple outlets pipelines in irrigation subunits.
Abstract
WOS: 000242429200004 Adequate hydraulic analysis of a multiple outlets pipelines is very important for the design and evaluation of irrigation systems. In this paper, an [...]
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Safe pedestrian crossings for children and elderly
L. Leden, P. Gårder, C. Johansson

Collection of closed articles in transport research (2006). Vol. 2006, 9

Abstract
In May 2000, the Swedish code governing the conduct of drivers at marked crosswalks became stricter with the intent to improve safety and mobility for pedestrians. A crash analysis based on a macro study of all of Sweden suggests that the injury risk in marked, not reconstructed, crosswalks increased by 27% for pedestrians and 19% for bicyclists. The reason for this may be that pedestrians get a false sense of safety with the new code. Reconstructions aiming at lowering speeds are indeed needed for the change of code to be positive. The 90-percentile speed should not exceed 30 km/h or safety will deteriorate."br/""br/"However, low speed by itself may not guarantee optimal safety. Safety can be further improved at sites, which already have been reconstructed to ensure low speeds. Results based on field data collected at sites close to schools in Malmö, Trollhättan and Borås in Sweden, and in-depth studies and other analyses of Finnish and Swedish police-reported crashes, suggest that safety of children and elderly is further improved at sites where visibility, orientation and clarity are sufficient. Also, marking crosswalks may increase yield rates (expected improvement 6%) towards pedestrians; and speed cushions situated at a longer distance from the marked crosswalk increase yield rates towards pedestrians and cyclists compared to speed cushions closer by.
Abstract
In May 2000, the Swedish code governing the conduct of drivers at marked crosswalks became stricter with the intent to improve safety and mobility for pedestrians. A crash [...]
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Oil pipeline spill cause analysis
M. Bertolini, M. Bevilacqua

Collection of closed articles in transport research (2006). Vol. 2006, 8

Abstract
Purpose – The purpose of this paper is to develop an easy and robust tool to develop a decision support system (DSS) for the inspection staff of oil pipelines. The aim is to predict “the class” of each spillage, with respect to some relevant variables such as, mechanical failure or system malfunction. The management will then be able to define which pipelines to monitor and to choose the most suitable monitoring policies, based on the decision tree analysis outcome. Design/methodology/approach – A non-parametric technique based on rule induction is proposed for the identification of the expected spill cause category of cross-country oil pipelines. In particular, the classification and regression trees approach is used to automatically generate inspection or maintenance decision rules. The analysis that is described is based on an extended database concerning information about spill cause category in cross-country oil pipelines in Western Europe. Findings – The proposed technique represents an interesting added value tool for the management. The proposed methodology extrapolates rules for determining the expected spill cause category of cross-country pipelines, depending on the boundary conditions. Practical implications – The methodology here presented will assist maintenance managers of oil pipeline to better plan maintenance activity. In particular, the procedure makes it possible to determine which parts of a pipeline have to be submitted to a monitoring action or particular protection, with the aim of improving the efficiency and reducing the risk of spillages. Originality/value – Effective planning, coordination, and scheduling of the maintenance function can be, and for many years was, accomplished without computer support. The proposed procedure may be included in an information systems tool (sound Computerized Maintenance Information Management System (CMMIS)), for more efficient and effective maintenance/inspection scheduling activitie
Abstract
Purpose – The purpose of this paper is to develop an easy and robust tool to develop a decision support system (DSS) for the inspection staff of oil pipelines. The aim is [...]
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Safety and accessibility effects of code modifications and traffic calming of an arterial road
P. Rosander, P. Gårder, L. Leden, P. Wikstrom

Collection of closed articles in transport research (2006). Vol. 2006, 7

Abstract
The European Road E12 through the community center of Storuman, Sweden was reconstructed in 1999 and 2000. Pedestrian walkways, traffic islands, chicanes of a type referred to as “Danish buns”, a roundabout and a two-directional cycle track along the E12 were installed. The purpose of the reconstruction was to improve safety for pedestrians and bicyclists, primarily for children, the elderly and the disabled, and to reduce the barrier effect of the E12 thoroughfare. In May 2000, the code governing the conduct of drivers at marked crosswalks in Sweden became stricter to improve safety and mobility for pedestrians. The combined effect of reconstructions and change of code was analyzed. Traffic behavior was studied at the intersection where the roundabout was constructed. Yield behavior towards pedestrians changed significantly. The difference was even greater with respect to yielding to child bicyclists – from 6% before to 84% after – even though the code change only related to pedestrians. Crash data analysis suggests a minor increase in fall injuries after reconstructions and change of code. Measures of speed, behavioral studies, questionnaires, face-to-face interviews and crash data analysis suggest that safety has increased not only along the E12 but also along adjacent roads. The final conclusion is that a bypass is not needed in a case like Storuman. Traffic calming of the main arterial through the town seems sufficient."br/""br
Abstract
The European Road E12 through the community center of Storuman, Sweden was reconstructed in 1999 and 2000. Pedestrian walkways, traffic islands, chicanes of a type referred [...]
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Finite difference simulation of ultrasonic NDE methods for the detection and sizing of Stress Corrosion Cracking (SCC)
M. Tomar, A. Volker, C. Wassink, M. Fingerhut, N. Pörtzgen

Collection of closed articles in transport research (2006). Vol. 2006, 5

Abstract
hough solutions for detection and sizing of longitudinal and circumferential cracks in pipeline walls exist, reliable detection and sizing of SCC in pipelines has been a challenge for Non Destructive Evaluation (NDE) for many years. Detection and sizing are impeded by the fact that SCC can have very irregular morphology and can occur in random orientations. NDE as an industry on the other hand has suffered from the emerging of many new UT techniques and a difficult jargon, making easy understanding of the actual problems and solutions impossible for an outsider (i.e. the pipeline operator). This paper presents a novel approach to provide insight into the capabilities of common NDE methods using finite difference simulation software developed by RTD. Simulations are performed on the most common morphologies of SCC using the most commonly used in-the-ditch NDE methods. Using the parameters of the actual inspection procedure a picture is painted of what works and doesn't work about the most common ways of accessing SCC. © 2006 American Institute of Physics.
Abstract
hough solutions for detection and sizing of longitudinal and circumferential cracks in pipeline walls exist, reliable detection and sizing of SCC in pipelines has been a challenge [...]
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Short-Term Prediction of Travel Time using Neural Networks on an Interurban Highway
S. Innamaa

Collection of closed articles in transport research (2005). Vol. 2005, 4

Abstract
The main purpose of this study was to investigate the predictability of travel time with a model based on travel time data measured in the field on an interurban highway. Another purpose was to determine whether the forecasts would be accurate enough to implement the model in an actual online travel time information service. The study was carried out on a 28-kilometre-long rural two-lane road section where traffic congestion was a problem during weekend peak hours. The section was equipped with an automatic travel time monitoring and information system. The prediction models were made as feedforward multilayer perceptron neural networks. The main results showed that the majority of the forecasts were close to the actual measured values. Consequently, use of the prediction model would improve the quality of travel time information based directly on the sum of the latest measured travel times.
Abstract
The main purpose of this study was to investigate the predictability of travel time with a model based on travel time data measured in the field on an interurban highway. [...]
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Costs of travel time uncertainty and benefits of travel time information: Conceptual model and numerical examples
H. Timmermans, D. Ettema

Collection of closed articles in transport research (2006). Vol. 2006, 3

Abstract
negative effect of congestion that tends to be overlooked is travel time uncertainty. Travel time uncertainty causes scheduling costs due to early or late arrival. The negative effects of travel time uncertainty can be reduced by providing travellers with travel time information, which improves their estimate of the expected travel time, thereby reducing scheduling costs. In order to assess the negative effects of uncertainty and the benefits of travel time information, this paper proposes a conceptual model of departure time choice under travel time uncertainty and information. The model is based on expected utility theory, and includes the variation in travel time, the quality of travel time information and travellers’ perception of the travel time. The model is illustrated by an application to the case of the A2 motorway between Beesd and Utrecht in the Netherlands.
Abstract
negative effect of congestion that tends to be overlooked is travel time uncertainty. Travel time uncertainty causes scheduling costs due to early or late arrival. The negative [...]
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Comparison of fuzzy logic and artificial neural networks approaches in
Y. Murat

Collection of closed articles in transport research (2006). Vol. 2006, 2

Abstract
Modeling vehicle delay has been an interesting subject for traffic engineers and urban planners. Determination of vehicle delay is a complex task and the delay is influenced by many variables that have uncertainties and vagueness, especially for non-uniform or over-saturated conditions. In this study, vehicle delay is modeled using new approaches such as Fuzzy Logic (FL) and Artificial Neural Networks (ANN) to deal with all conditions. The Neuro Fuzzy Delay Estimation (NFDE) model and Artificial Neural Networks Delay Estimation (ANNDE) model are developed. The overall delay data required for the model were collected from ten signalized intersections in Turkey. The results of the developed models are compared with the Highway Capacity Manual (HCM), Akqelik's methods and the delay data collected from intersections. The results showed that delay estimations by the ANNDE and NFDE model are promising. It is also inferred that the NFDE model results are the best fitted. The Average Relative Error (ARE) rates of NFDE model are determined as 7% for under-saturated and 5% for over-saturated conditions. The results reflect the fact that the neuro-fuzzy approach may be used as a promising method in vehicle delay estimation. (c) 2006 Elsevier Ltd. All rights reserved. C1 Pamukkale Univ, Fac Engn, Dept Civil Engn, TR-20070 Kinikli, Denizli, Turkey.
Abstract
Modeling vehicle delay has been an interesting subject for traffic engineers and urban planners. Determination of vehicle delay is a complex task and the delay is influenced [...]
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A RE-ASSESSMENT OF OLDER DRIVERS AS A ROAD SAFETY RISK
B. Fildes, J. Charlton, S. Newstead, J. Langford, S. Koppel

Collection of open articles in transport research (2006). Vol. 2006, 6

Abstract
Older drivers are frequently viewed as overly represented in crashes, particularly when crash involvement per distance travelled is considered. This perception has led to a call for tighter licensing conditions for older drivers, a policy which inevitably results in mobility restrictions for at least some drivers. However there is a growing body of research evidence which shows that as a group, older drivers represent no greater road risk than drivers from other age groups once different levels of driving activity are taken into account. This paper has examined aspects of older drivers' fitness to drive based on survey data and off-road and on-road driving performance from a sample of 905 New Zealand older drivers. The results show that policies which target all older drivers and lead to licensing and mobility restrictions cannot be justified from a safety basis. Document type: Article
Abstract
Older drivers are frequently viewed as overly represented in crashes, particularly when crash involvement per distance travelled is considered. This perception has led to [...]
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Analysis of transport performance indicators
M. Išoraite

Collection of open articles in transport research (2005). Vol. 2005, 7

Abstract
The article analyses the following issues: 1) key performance indicators, 2) best value indicators, 3) performance indicators and the change process, 4) transport programme indicators inputs, outputs, results and impacts, 5) indicators of effectiveness, efficiency and performance, 6) overcoming of the problems of using indicators, 7) criteria of the establishment of performance indicator system. First Published Online: 27 Oct 2010 Document type: Article
Abstract
The article analyses the following issues: 1) key performance indicators, 2) best value indicators, 3) performance indicators and the change process, 4) transport programme [...]
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SELF-REPORTED DIFFERENCES BETWEEN CRASH-INVOLVED AND NON-CRASH-INVOLVED THREE-WHEELER DRIVERS IN SRI LANKA
R. Tay, A. Somasundaraswaran

Collection of open articles in transport research (2006). Vol. 2006, 5

Abstract
Despite being an important mode of transportation in the developing world, little research has been conducted to understand the factors contributing to crashes involving three wheel vehicles. This study surveyed a convenient sample of 505 professional three-wheeler drivers in Sri Lanka to explore the similarities and differences in the demographic and work characteristics between three-wheeler drivers who reported experiencing at least one collision in the past twelve months and those who reported that they were not involved in any collisions. Our study revealed some interesting results that were quite different from those obtained in the studies on professional drivers in developed countries. In particular, both drivers with less than one year and more than five years of driving experience in our study were found to be associated with higher probability of crash involvement. Also, the number of trips per day and the average travel distance per trip were found to be insignificant in delineating between crash-involved and non-crash-involved drivers. Moreover, crash-involved drivers, on average, have significantly fewer working days per week and fewer hours per day, suggesting that the conventional approach used in most developed countries to tackle fatigue among professional drivers do not appear to be suitable for solving the road safety problem involving three-wheeler drivers in a developing country. Also, since the age of most drivers falls in a narrow range, this U-shaped relationship is not likely to be a result of youth and ageing but of inexperience in newer drivers and complacency in more experienced drivers. Lastly, since a relatively large proportion of the drivers had driven without a valid driving license, legislation and enforcement interventions are likely to be less effective than education and engineering countermeasures. Document type: Article
Abstract
Despite being an important mode of transportation in the developing world, little research has been conducted to understand the factors contributing to crashes involving three [...]
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TECHNOLOGICAL DEVELOPMENT OF DRIVING SUPPORT SYSTEMS BASED ON HUMAN BEHAVIORAL CHARACTERISTICS
S. Doi

Collection of open articles in transport research (2006). Vol. 2006, 4

Abstract
Driving support and cruise assist systems are of growing importance in achieving both road traffic safety and convenience. Such driver support seeks to achieve, with the highest possible quality, nothing less than “driver-vehicle symbiosis under all conditions.” At the same time, many traffic accidents result from improper driver behavior. The author focuses on driver behavior under various driving conditions, conducting detailed measurement and analysis of visual perception and attention characteristics as well as perceptual characteristics involved in driving. The aim in doing so is to support research on driving support systems and driving workload reduction technologies that function as human-vehicle systems and take such characteristics into account. Document type: Article
Abstract
Driving support and cruise assist systems are of growing importance in achieving both road traffic safety and convenience. Such driver support seeks to achieve, with the highest [...]
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Seakeeping of a fast displacement catamaran
V. Dyachkov, J. Makov

Collection of open articles in transport research (2005). Vol. 2005, 5

Abstract
The paper presents a complex method for the calculation of pitch and heave of a fast displacement catamaran. It incorporates speed factors, interference of catamaran hulls, stabilization factors and possibility to apply different stabilization cases including a stabilizer activation possibility. In the method the possibility to evaluate catamaran motions in irregular waves is also included. On the base of the presented method the computer program is developed and applied to calculate seakeeping characteristics of a catamaran stabilized with a fore passive wing. The results of calculation are in good compatibility with the experimental model tests of this catamaran in irregular waves. The calculation method could be effectively applied in the design stage of fast displacement catamarans or of fin stabilizers determining their effectiveness. First Published Online: 27 Oct 2010 Document type: Article
Abstract
The paper presents a complex method for the calculation of pitch and heave of a fast displacement catamaran. It incorporates speed factors, interference of catamaran hulls, [...]
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Is there a trend in cirrus cloud cover due to aircraft traffic?
D. Lee, D. Arlander, G. Myhre, G. Myhre, W. Rossow, T. Svendby, E. Stordal, F. Stordal

Collection of open articles in transport research (2005). Vol. 2005, 4

Abstract
Abstract. Trends in cirrus cloud cover have been estimated based on 16 years of data from ISCCP (International Satellite Cloud Climatology Project). The results have been spatially correlated with aircraft density data to determine the changes in cirrus cloud cover due to aircraft traffic. The correlations are only moderate, as many other factors have also contributed to changes in cirrus. Still we regard the results to be indicative of an impact of aircraft on cirrus amount. The main emphasis of our study is on the area covered by the METEOSAT satellite to avoid trends in the ISCCP data resulting from changing satellite viewing geometry. In Europe, which is within the METEOSAT region, we find indications of a trend of about 1-2% cloud cover per decade due to aircraft, in reasonable agreement with previous studies. The positive trend in cirrus in areas of high aircraft traffic contrasts with a general negative trend in cirrus. Extrapolation in time to cover the entire period of aircraft operations and in space to cover the global scale yields a mean estimate of 0.03 Wm-2 (lower limit 0.01, upper limit 0.08 Wm-2) for the radiative forcing due to aircraft induced cirrus. The mean is close to the value given by IPCC (1999) as an upper limit. Document type: Article
Abstract
Abstract. Trends in cirrus cloud cover have been estimated based on 16 years of data from ISCCP (International Satellite Cloud Climatology Project). The results have been [...]
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USING THE SAFE SYSTEM APPROACH TO KEEP OLDER DRIVERS SAFELY MOBILE
J. Oxley, J. Langford

Collection of open articles in transport research (2006). Vol. 2006, 3

Abstract
In 2003, Australian road transport jurisdictions collectively accepted that the greatest road safety gains would be achieved through adopting a Safe System approach, derived from Sweden's Vision Zero and the Netherlands' Sustainable Safety strategies. A key objective of all three approaches is to manage vehicles, the road infrastructure, speeds, road users and the interactions between these components, to ensure that in the event of crashes, crash energies will remain at levels that minimize the probability of death and serious injury. Older drivers pose a particular challenge to the Safe System approach, given particularly their greater physical frailty, their driving patterns and for some at least, their reduced fitness to drive. This paper has analyzed the so-called ‘older driver problem’ and identified a number of key factors underpinning their crash levels, for which countermeasures can be identified and implemented within a Safe System framework. The recommended countermeasures consist of: (1) safer roads, through a series of design improvements particularly governing urban intersections; (2) safer vehicles, through both the promotion of crashworthiness as a critical consideration when purchasing a vehicle and the wide use of developed and developing ITS technologies; (3) safer speeds especially at intersections; and (4) safer road users, through both improved assessment procedures to identify the minority of older drivers with reduced fitness to drive and educational efforts to encourage safer driving habits particularly but not only through self-regulation. Document type: Article
Abstract
In 2003, Australian road transport jurisdictions collectively accepted that the greatest road safety gains would be achieved through adopting a Safe System approach, derived [...]
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COGNITIVE AND PHYSICAL FACTORS IN CHANGES TO THE AUTOMOBILE DRIVING ABILITY OF ELDERLY PEOPLE AND THEIR MOBILITY LIFE
J. Takahashi, M. Akamatsu, A. Iwasaki, H. Daigo, K. Hayama

Collection of open articles in transport research (2006). Vol. 2006, 2

Abstract
We analyzed cognitive and physical changes in driving by aging drivers based on responses to a questionnaire delivered to elderly and non-elderly drivers in various regions of Japan. Factor analysis of the 27-item questionnaire indicated that four factors related to cognitive change while three factors related to driver physical change and task-oriented change. We adopted the situation awareness cognitive-behavioral model to examine relationships among derived factors. The four cognitive factors corresponded to the elements in the cognitive-behavioral process for automobile driving. The other three factors impact the cognitive-behavioral process. Investigation of the effects of demographic (age and area of residence) and automobile usage characteristics (driving frequency and annual mileage) on the factor scores revealed that cognitive and physical changes depended not only upon age but also on area of residence and automobile usage. From this results, daily driving experience was considered to influence cognitive and physical function. We analyzed the effect of cognitive and physical change on the level of satisfaction in using other modes of transportation from the perspective of elderly mobility. We found that drivers who scored higher for change in automobile driving skills remained satisfied with automobile use but not the use of public buses. Document type: Article
Abstract
We analyzed cognitive and physical changes in driving by aging drivers based on responses to a questionnaire delivered to elderly and non-elderly drivers in various regions [...]
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Standard life
D. Allen

Collection of restricted reports in transport research (2021). Vol. 2005, 2
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Combining technical and behavioral change
B. Elzen

Collection of closed chapters of books in transport research (2021). Vol. 2006, 4

Abstract
well functioning traffic and transport system is a necessity for an industrialized and complex society. The way in which the existing transport system is shaped and functions, however, causes major societal problems. Emissions of pollutants from vehicles create health hazards to humans and other living species. CO2-emissions contribute to global warming. The continuously increasing numbers of vehicles cause congestion, worsen accessibility of many destinations and threaten the livability of cities and living quarters.
Abstract
well functioning traffic and transport system is a necessity for an industrialized and complex society. The way in which the existing transport system is shaped and functions, [...]
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Constraint-Based Routing in Traffic Engineering
A. Karaman

Collection of closed conferences in transport research (2021). Vol. 2006, 5

Abstract
Traffic engineering (TE) describes a domain-wide perspective for traffic control as opposed to application-specific concerns of QoS. MPLS is today's most powerful architecture for TE. Constraint-based routing refers to the process of path assignment to flows to fulfill the TE objective which has been defined in a number of multi-constraint ways, and is the most significant component of TE. In this paper, we review constraint-based routing algorithms. We first provide an overview of MPLS/TE and place constraint-based routing within this approach. We then look into the potential path attributes and the underlying platform to characterize these algorithms before we present our review. Our study provides a comprehensive reference to the operational structure and specifications of constraint-based routing algorithms. Publisher's Version
Abstract
Traffic engineering (TE) describes a domain-wide perspective for traffic control as opposed to application-specific concerns of QoS. MPLS is today's most powerful architecture [...]
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Reusable learning objects (RLOs) for computer science students
B. Balci, M. Inceoglu

Collection of closed conferences in transport research (2021). Vol. 2006, 4

Abstract
International Conference on Computational Science and Its Applications (ICCSA 2006) -- MAY 08-AUG 11, 2006 -- Glasgow, SCOTLAND WOS: 000237642900040 The purpose of this study is to introduce an instructional technology known as the "learning object". After a review of the literature, the designing steps of a learning object (LO) are tried to explain. As a learning object standard a few details are given about SCORM-Content Aggregation Model and common metadata elements. At the end, a case study about designing of a learning object with the subject of "Congestion Control in Computer Networks" is tried to give. The content is prepared in English and it contains 13 pictures within 22 him and 3 .exe files. The basic principles of the network congestion and the designed congestion control algorithms are given in the him pages. Simulators are used to show the working way of the related algorithms step by step. The LO design is made with an open source program RELOAD Editor, according to the ADL SCORM package. The designed LO has been tested on computer engineering students and positive feedbacks are received. IEE, Univ Perugia, Univ Calgary, Univ Minnesota, Queens Univ, Belfast, ERCIM, OptimaNumerics, INTEL, AMD
Abstract
International Conference on Computational Science and Its Applications (ICCSA 2006) -- MAY 08-AUG 11, 2006 -- Glasgow, SCOTLAND WOS: 000237642900040 The purpose of this study [...]
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TIME SERIES MODELS TO FORECAST AIR TRANSPORT DEMAND: A STUDY ABOUT A REGIONAL AIRPORT
M. Postorino, A. Andreoni

Collection of closed conferences in transport research (2021). Vol. 2006, 2

Abstract
In this work, both univariate and multivariate air transport demand ARIMA models are proposed to estimate the demand levels about Reggio Calabria regional airport (South of Italy), in order to make available a tool able to analyse the impact of recent modifications in the supply (new links, new destinations and lower fares) that are expected to produce an increase in the air transport demand, also due to induced trips generated by the new supply. Differences between the univariate and multivariate models are highlighted. The models calibrations have been obtained by using the Box-Jenkins procedure.
Abstract
In this work, both univariate and multivariate air transport demand ARIMA models are proposed to estimate the demand levels about Reggio Calabria regional airport (South of [...]
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Performance Evaluation and Improvement of Algorithmic Approaches for Packet Classification
J. Li, B. Xu, Y. Qi

Collection of open conferences in research transport (2005). Vol. 2005, 135

Abstract
Packet classification is crucial to the implementation of several advanced services that require the capability to distinguish traffic in different flows, such as firewalls, intrusion detection systems, and many QoS implementations. Although hardware solutions, such as TCAMs, provide high search speed, they do not scale to large rulesets. Instead, some of the most promising algorithmic research embraces the practice of leveraging the data redundancy in real-life rulesets to improve high performance packet classification. In this paper, we provide a general framework for discerning relationships and distinctions of the design-space of existing packet classification algorithms. Several best-known algorithms, such as RFC and HiCuts/HyperCuts, are carefully analyzed based on this framework, and an improved scheme for each algorithm is proposed. All algorithms studied in this paper, along with their variations, are objectively assessed using both real-life and synthetic rulesets. The source codes of these algorithms are made publicly available on Web-site
Abstract
Packet classification is crucial to the implementation of several advanced services that require the capability to distinguish traffic in different flows, such as firewalls, [...]
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Flexible implementation of genetic algorithms on FPGAs
N. Shibata, K. Yasumoto, T. Tachibana, M. Ito, Y. Murata

Collection of open conferences in research transport (2006). Vol. 2006, 148

Abstract
Genetic algorithms (GAs) are useful since they can find near optimal solutions for combinatorial optimization problems quickly. Although there are many mobile/home applications of GAs such as navigation systems, QoS routing and video encoding systems, it was difficult to apply GAs to those applications due to low computational power of mobile/home appliances. In this paper, we propose a technique to flexibly implement genetic algorithms for various problems on FPGAs. For the purpose, we propose a basic architecture which consists of several modules for GA operations to compose a GA pipeline, and a parallel architecture consisting of multiple concurrent pipelines. The proposed architectures are simple enough to be implemented on FPGAs, applicable to various problems, and easy to estimate the size of the resulting circuit. We also propose a model for predicting the size of resulting circuit from given parameters consisting of the problem size, the number of concurrent pipelines and the number of candidate solutions for GA. Based on the proposed method, we have implemented a tool to facilitate GA circuit design and development. This tool allows designers to find appropriate parameter values so that the resulting circuit can be accommodated in the target FPGA device, and to automatically obtain RTL VHDL description. Through experiments using Knapsack Problem and TSP, we show that the FPGA circuits synthesized based on the proposed method run much faster and consume much lower power than software implementation on a PC and that our model can predict the size of the resulting circuit accurately enough.
Abstract
Genetic algorithms (GAs) are useful since they can find near optimal solutions for combinatorial optimization problems quickly. Although there are many mobile/home applications [...]
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Deepwater Pipelines: Reliability of Finite Element Models in the Prediction of Collapse and Collapse Propagation Loads
R. Toscano, E. Dvorkin

Collection of open conferences in research transport (2006). Vol. 2006, 145

Abstract
In the design of pipelines it is of utmost importance to use validated numerical tools, usually finite element models, to reliably determine the structural limit loads. Also for steel pipes manufacturers it is very important, for establishing the set-up of their production processes, to be able to analyze using validated finite element models the effect that different manufacturing imperfections have on the pipe limit loads (e.g. “ovalization” of the external diameter, eccentricity, residual stresses, etc.). For deepwater pipelines the most relevant limit states that need to be analyzed are the collapse and collapse propagation under different combinations of external pressure and bending. In the second section of this paper we discuss the finite element models that we developed to predict the collapse and collapse propagation of seamless steel pipes under external pressure and bending. The validation of these models was performed comparing the numerical results with experimental results obtained at CFER (Edmonton, Canada) [1] and at our lab for the pre-collapse and post-collapse regimes. In deepwater pipelines, in order to prevent the propagation of collapse failures through the pipeline length, buckle arrestors are used. In the third section of this paper we review the finite element models that we developed to predict buckle arrestors cross-over external pressures. The validation of these models was performed comparing the numerical results with experimental ones obtained at our lab for different ratios [arrestor thickness/pipe thickness] corresponding to either the flattening or flipping cross-over mechanisms [2]. Finally in the fourth section of this paper the validated finite element models are used to perform parametric analyses that provide useful data for pipeline engineers on the effect of different geometrical parameters on crossover pressure.Copyright © 2006 by ASME
Abstract
In the design of pipelines it is of utmost importance to use validated numerical tools, usually finite element models, to reliably determine the structural limit loads. Also [...]
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Analysis of Girth Welds in Pipelines Subjected to Lifting Loads
C. Alexander, R. Scrivner

Collection of open conferences in research transport (2006). Vol. 2006, 143

Abstract
Williams Gas Pipeline requested that Stress Engineering Services provide engineering services to analytically assess issues that occurred in a 30-inch pipeline due to cracked girth welds. The focus of the analytical effort was to simulate the lifting during the pipeline construction process. Using finite element methods, nominal bending stresses were calculated considering a specific set of criteria including 80-foot pipe joints, skid locations, and a given root pass weld thickness. These bending stresses were used to calculate a total stress that included stress concentration factors (SCFs) due to hi-low weld mismatch and weld profile geometry. For conservatism, residual stresses were also included in computing the total stress. As an example, the results showed that if a residual stress of 50 percent yield and a total SCF of 4.5 are assumed, the lift height should be limited to approximately 9 inches for a root pass weld thickness of 0.0625 inches. In this calculation, a stress limit of two times yield was used. Once the final stress was computed considering the range of variables, a closed-form equation was developed that integrated the variables of interest for the 30-inch pipe. This equation was used to compute data points to guide Williams in establishing permissible lift heights for a range of SCFs for the welds. A stress limit of two times the yield strength was selected as the limiting value. The details of the work presented in this paper will assist pipeline operators in developing a protocol that balances the need for rapid construction and ensuring that proper girth welds are fabricated.Copyright © 2006 by ASME
Abstract
Williams Gas Pipeline requested that Stress Engineering Services provide engineering services to analytically assess issues that occurred in a 30-inch pipeline due to cracked [...]
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STREAM - Strategic Realtime control for Megalopolis-traffic
T. Usami, S. Miyata

Collection of open conferences in research transport (2005). Vol. 2005, 134

Abstract
STREAM is a real time signal control system aimed at alleviating traffic congestion, distributing traffic and reducing the number of road accidents. It is applicable to all traffic conditions moderating the speed of vehicles in light traffic, improving the efficiency of green time when traffic demand is nearly saturated and running priority control when demand is over-saturated. This paper discusses the concept of control, the system configuration, the control methods and the results obtained from introducing STREAM in Tokyo. The results show a reduction in daytime journey time of 9%, a reduction in total delay of 23% and a reduction in congestion length time of 28%. For the covering abstract see IRRD 880251.
Abstract
STREAM is a real time signal control system aimed at alleviating traffic congestion, distributing traffic and reducing the number of road accidents. It is applicable to all [...]
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Influence of Multilayer Traffic Engineering Timing Parameters on Network Performance
B. Puype, D. Colle, P. Demeester, M. Pickavet

Collection of open conferences in research transport (2006). Vol. 2006, 141

Abstract
Recent advances in optical networking technology have moved the state-of-the-art from manually installed fiber connections to fully automatic switched lightpaths. Multilayer Traffic Engineering (MTE) in an IP-over-Optical network allows to leverage rapid lightpath setup/teardown as a cross-layer traffic engineering technique. It enables on-the-fly reconfiguration of the IP layer logical topology and up/downgrade of the capacity of IP links. Together with classical IP layer routing techniques, MTE intelligently solves problems such as IP layer congestion and packet loss and it may optimize optical layer capacity usage and total network throughput. In this, the rate at which MTE can make adjustments to the network is limited by technology and stability concerns. We present some example MTE techniques and discuss how the timing parameters of these mechanisms impact perceived network performance.
Abstract
Recent advances in optical networking technology have moved the state-of-the-art from manually installed fiber connections to fully automatic switched lightpaths. Multilayer [...]
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A Multi-Agent System Architecture for Distributed Air Traffic Control
C. Stirling, J. Hill, J. Archibald, R. Frost

Collection of open conferences in research transport (2005). Vol. 2005, 132

Abstract
The next generation of air traffic control will require automation in order to meet safety, reliability, flexibility, and robustness demands in an environment of steadily increasing air traffic density. Optimization, however, is an inadequate paradigm for the design of a cooperative distributed air traffic control system. The problem stems from a fundamental limitation of von Neumann-Morgenstern utilities, which do not account for sophisticated social behavior such as situational altruism. Social utility functions overcome this limitation by permitting decision makers to expand their spheres of interest beyond the self via conditional utilities. Satisficing game theory provides a decision strategy that permits decision makers to compromise in the interest of achieving both individual and group goals and presents a mathematical framework for the design of sophisticated cooperative multiagent societies. Simulation results in a variety of geometric scenarios show promising performance in terms of efficiency and flexibility even with high traffic densities.
Abstract
The next generation of air traffic control will require automation in order to meet safety, reliability, flexibility, and robustness demands in an environment of steadily [...]
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Field Measurements of Unsteady Friction Effects in a Trunk Transmission Pipeline
J. Vítkovský, A. Simpson, M. Stephens, M. Lambert

Collection of open conferences in research transport (2005). Vol. 2005, 131

Abstract
The relative importance of unsteady friction effects in real pipelines remains a matter of debate. This paper presents the results of a set of field transient measurements on a 13.5 km long trunk transmission water pipeline located in regional South Australia. Modelling has been undertaken using efficient rough pipe turbulent weighting function methods to calculate the unsteady friction contribution. The relative importance of unsteady friction, for no-leak and leak cases, is assessed.
Abstract
The relative importance of unsteady friction effects in real pipelines remains a matter of debate. This paper presents the results of a set of field transient measurements [...]
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A Flatness Based Flight Guidance Control Using Neural Networks
F. Mora-Camino, W. Lu, K. Achaibou

Collection of open conferences in research transport (2005). Vol. 2005, 128

Abstract
The increasing air traffic flow around most airports of regional hubs and big cities worldwide inevitably leads to saturation problems and strongly drives the researchers to find out new solutions to this issue. In this communication, we try to propose a solution to this problem from the standing of flight guidance control approach. The differentially flat system theory is introduced as the basis of the proposed flight guidance control approach. In this study, the differential flatness property of flight guidance dynamics is presented. With the help of neural networks to numerically resolve the implicit dynamic equations, the nominal guidance control input can be obtained. With the considerable generalization problem, modeling errors and anticipated disturbance in practical application, an additional feedback loop is implemented to improve the trajectory tracking performance. The preliminary simulation results for vertical trajectory tracking display the feasibility of this flatness based neural flight guidance control scheme.
Abstract
The increasing air traffic flow around most airports of regional hubs and big cities worldwide inevitably leads to saturation problems and strongly drives the researchers [...]
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Infrastructure concept for automated aircraft and air traffic operations
H. Rediess

Collection of open conferences in research transport (2005). Vol. 2005, 127

Abstract
The infrastructure supporting our current air transportation system has evolved as a combination of separate systems interconnected to serve the needs of pilots and air traffic control (ATC). The human-centric approach to ATC with multiple levels of backup capability has proven very safe and has provided efficient service until the late 1990's when air traffic approached system capacity limits. As traffic demand increases there is concern that the number of aircraft operations may exceed the human's ability to directly control individual aircraft, even with sophisticated decision support tools. Various automation approaches to air traffic management (ATM) for handling more aircraft operations are being investigated at an algorithmic level. Assuming automation algorithms are developed that could handle significantly more traffic than human controllers, could they be implemented safely with the current infrastructure, which was designed for human operation and intervention? An infrastructure design approach is introduced for supporting fully automatic operations of aircraft and ATM. It is based on an integrated design of communication, space positioning and ATM functions using satellite, airborne and terrestrial elements. Such an infrastructure could support civil uninhabited air vehicles (UAV) application and enable highly automated personal air vehicles.
Abstract
The infrastructure supporting our current air transportation system has evolved as a combination of separate systems interconnected to serve the needs of pilots and air traffic [...]
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FATE: A Polynomial Time Framework for Flow Allocation in MPLS-TE Networks
S. Lahoud, G. Texier, L. Toutain

Collection of open conferences in research transport (2005). Vol. 2005, 126

Abstract
International audience; In this paper, we present a novel polynomial time framework for the off-line flow allocation problem in MPLSTraffic Engineering (MPLS-TE) networks. This framework, named FATE (Flow Allocation for Traffic Engineering), encompasses different objectives that illustrate the operator needs for traffic engineering and provides advanced control over the quality of the solution. Typically, we consider minimizing congestion, bandwidth consumption and operational costs. FATE is based on linear programming and presents an efficient solution for the problem both in terms of computational complexity and approximation guarantees. Simulation results show that we can get an efficient trade-off between congestion and bandwidth consumption while having a reduced number of Label Switched Paths (LSPs) for various known topologies.
Abstract
International audience; In this paper, we present a novel polynomial time framework for the off-line flow allocation problem in MPLSTraffic Engineering (MPLS-TE) networks. [...]
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Fatigue Crack Growth Rates in Six Pipeline Steels
J. McColskey, J. Merritt, A. Bussiba, C. McCowan, G. Kohn, P. Darcis, R. Smith

Collection of open conferences in research transport (2006). Vol. 2006, 140

Abstract
This study presents fatigue data for six different pipeline steels, with strengths ranging from Grade B to X100. A fatigue crack growth test for full thickness pipeline samples was developed using a Middle Tension (MT) type specimen. The six steels showed similar fatigue crack growth rate (da/dN) behavior. There were only minor differences among the steels for the threshold values and most of the stable crack growth regime. Larger differences were observed in the final stages of crack growth and fatigue failure. The effect of compressive residual stresses at the outer surface of the pipeline was also examined. A Failure Assessment Diagram technique was used to evaluate the potential failures modes of the six pipeline steels, containing, as an example, an internal surface, semi-elliptic, axially oriented flaw. Mixed-mode failure was predicted for all of the steels.Copyright © 2006 by ASME
Abstract
This study presents fatigue data for six different pipeline steels, with strengths ranging from Grade B to X100. A fatigue crack growth test for full thickness pipeline samples [...]
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Electrostatic sensors applied to the measurement of electric\\ud charge transfer in gas-solids pipelines
J. Denham, S. Woodhead, D. Armour-Chelu

Collection of open conferences in research transport (2005). Vol. 2005, 125

Abstract
This paper describes the development of a number of electric charge sensors. The sensors have been developed specifically to investigate triboelectric charge transfer which takes place between particles and the pipeline wall, when powdered materials are conveyed through a pipeline using air. A number of industrial applications exist for such gas–solids pipelines, including pneumatic conveyors, vacuum cleaners and dust extraction systems. The build-up of electric charge on pipelines and powdered materials can lead to electrostatic discharge and so is of interest from a safety viewpoint. The charging of powders can also adversely affect their mechanical handling characteristics and so is of interest to handling equipment engineers. The paper presents the design of the sensors, the design of the electric charge test rig and electric charge measurement test results. Document type: Conference object
Abstract
This paper describes the development of a number of electric charge sensors. The sensors have been developed specifically to investigate triboelectric charge transfer which [...]
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Assessing the Use of Composite Materials in Repairing Mechanical Damage in Transmission Pipelines
C. Alexander, F. Worth

Collection of open conferences in research transport (2006). Vol. 2006, 136

Abstract
Mechanical damage involving dents with gouges is one of the leading causes of transmission pipeline failures in terms of both static and cyclic pressure loading. Because of the severity of this defect type, pipeline companies are required to respond to these anomalies by either removing damaged sections or repair using welded sleeves. For more than 10 years, composite materials have been used to repair corroded pipelines and their use has gained wide acceptance across the pipeline industry. Numerous systems have been tested with results being presented in the open literature. Testing was recently performed to assess the use of a water-activated composite repair system, Aquawrap® , in terms of its ability to repair mechanical damage subjected to cyclic pressure service. The Aquawrap® repair system has been extensively tested on corrosion defects but testing on pipes with dents had not been done. The water activated pre-preg urethane resin system offers excellent long tern (creep-rupture) strength combined with easy low cost field installation. Pipes having diameter to wall thickness ratios ranging from 34 to 68 were fitted with dents and gouges. Repair involved removing the gouged material of the pipe after indentation and repairing using the composite sleeve. The result of this specific test program showed that on-average the fatigue life for mechanically-damaged pipes can be increased on the order of three orders of magnitude when repaired by grinding and installing composite sleeves. This paper provides details on the methodology of the test program, results, and most importantly, information that can be used by operators in repairing their pipeline systems.Copyright © 2006 by ASME
Abstract
Mechanical damage involving dents with gouges is one of the leading causes of transmission pipeline failures in terms of both static and cyclic pressure loading. Because of [...]
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A distributed simulation model of air traffic in the national airspace system
A. Zukas, F. Wieland, E. Blair

Collection of open conferences in research transport (2005). Vol. 2005, 123

Abstract
The study of air transportation systems is a prime opportunity for the application of simulation modeling. The complexity and highly interdependent nature of the national air transportation system makes it difficult to study, even through simulation. As a result, models of this system are typically large and require long run times. This paper reports on a model designed to apply the emerging technology of parallel/distributed computing to facilitate the rapid analysis of national-scope air transportation systems. The model makes extensive use of the SPEEDES distributed simulation support software developed at the Jet Propulsion Laboratory by Dr. Jeff Steinman.
Abstract
The study of air transportation systems is a prime opportunity for the application of simulation modeling. The complexity and highly interdependent nature of the national [...]
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The power of SIMDs vs. MIMDs in real-time scheduling
J. Baker, M. Jin, W. Meilander

Collection of open conferences in research transport (2005). Vol. 2005, 122

Abstract
SIMDs and MIMDs are the most important categories of computer systems for parallel computing in Flynn’s classification scheme. Due to their higher flexibility in allowing processors to execute independently and their ability to use off-the-shelf microprocessors, the MIMD systems are generally favored and considered to be more powerful. In comparison, the SIMD systems are considered outdated. However, we observe that many intrinsic weaknesses of the MIMD systems are not fully recognized until they are compared while solving realtime scheduling problems. The SIMD systems have inherent advantages that MIMDs lack. In this paper, we compare SIMDs and MIMDs in real-time scheduling, e.g., scheduling for air traffic control. Two abstract parallel computation models, the ASC and BSP models that represent SIMDs and MIMDs respectively, are used in our discussion and analysis. We argue that the common belief that MIMDs have greater power than SIMDs is false. Our research shows that SIMDs are not outdated, as they offer tractable solutions for problems considered intractable with MIMDs. Rather, SIMDs are more efficient and powerful in some important application fields. They deserve more attention and considerations than they currently receive.
Abstract
SIMDs and MIMDs are the most important categories of computer systems for parallel computing in Flynn’s classification scheme. Due to their higher flexibility in allowing [...]
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An H.264/AVC Decoder with 4X4-Block Level Pipeline
T. Lin, C. Lee, T. Liu, S. Wang

Collection of open conferences in research transport (2005). Vol. 2005, 121

Abstract
In this paper, we propose a 4/spl times/4-block level pipelining architecture with instantaneous switching scheme and optimal decoding ordering of H.264/AVC decoder. Compared with conventional H.264/AVC video decoders, which adopt macroblock level pipelines, our proposed 4/spl times/4-block level pipelining architecture of H.264/AVC decoder achieves better hardware utilization. Moreover, our proposed decoding ordering can effectively save memory access and reduce processing cycles, which results in 260000 MB/s under 100 MHz clock frequency. By adopting these two techniques, our proposed design supports real time decoding with 1080HD (1920/spl times/1088) video sequence in 30fps (244800 MB/s required) and level 4 of baseline profile.
Abstract
In this paper, we propose a 4/spl times/4-block level pipelining architecture with instantaneous switching scheme and optimal decoding ordering of H.264/AVC decoder. Compared [...]
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Designing adaptive architectures for transoceanic in flight communications
B. Green, R. Slywczak, O. Mezu

Collection of open conferences in research transport (2005). Vol. 2005, 119

Abstract
During commercial flights, pilots require continuous communications and seamless access to data products, such as graphical weather maps and turbulence alerts, to proactively react to dynamic flight conditions. NASA/Glenn Research Center (GRC) and the weather information communications (WINCOMM) project have been researching methods to improve communications and to disseminate graphical weather data products to aircraft flying in the transoceanic region where en route weather collection and dissemination are minimal. The goal is to employ commercial satellite-based communications and packet switching technologies to provide a cost effective and efficient communications solution for aviation. This paper describes the goals of the WINCOMM program and the research related to the transoceanic scenario. It describes the flight architecture and the proposed communication network that is currently being implemented in the laboratory. The main goal is to have a seamless but efficient separation of services between the cockpit and cabin data with both data existing on the same data link. The initial findings for the quality of service (QoS) research is presented along with the techniques for implementing QoS in Cisco routers and the design of the QoS schemes for the transoceanic testbed. Data for the testing initially focus on sending informational and graphical weather data but eventually encompass warning/cockpit alerts and, hopefully, air traffic control messages. In mid-2005, the laboratory setting can be flight tested aboard the Langley Research Center's (LaRC) Boeing-757.
Abstract
During commercial flights, pilots require continuous communications and seamless access to data products, such as graphical weather maps and turbulence alerts, to proactively [...]
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Architecture d'une boîte à outils d'algorithmes d'ingénierie de trafic et application au réseau GEANT
F. Skivée, S. Balon, O. Delcourt, J. Lepropre, G. Leduc

Collection of open conferences in research transport (2005). Vol. 2005, 117

Abstract
This paper presents the software architecture of a traffic engineering toolbox. The methods already included cover MPLS-based intra-domain traffic engineering (TE), but will soon cover IP-based TE and inter-domain TE. This toolbox provides an open source software that allows an operator to test methods coming from the academic research. A researcher can also use the toolbox for comparing and promoting his/her TE algorithms. The toolbox is designed to be deployed as an on-line tool in a operational network or as a traffic engineering simulator. We present a case study of traffic optimisation on the GÉANT network that compares different routing algorithms, evaluates different protection cost, and analyses the worst-case link failure. Cet article présente l'architecture logicielle d'une boîte à outils d'ingénierie de trafic (Disponible à l'adresse http://totem.run.montefiore.ulg.ac.be).Les méthodes déjà présentes couvrent l'ingénierie de trafic intra-domaine basée sur MPLS, mais devraient bientôt couvrir l'ingénierie de trafic inter-domaine, ainsi que celle basée sur IP. L'objectif de cette boîte à outils est de fournir un logiciel libre permettant à un opérateur de tester des outils issus de la recherche académique et à un chercheur de comparer et promouvoir ses algorithmes d'ingénierie de trafic. La boîte à outils est conçue pour être déployée comme un outil on-line dans un environnement opérationnel, ou comme un outil d'optimisation off-line ou encore comme un simulateur d'ingénierie de trafic. Nous avons réalisé une étude de cas d'optimisation de trafic sur le réseau GÉANT. Cette étude présente une comparaison de différentes méthodes de routage, une évaluation du coût d'une protection de bout en bout ou locale ainsi que l'analyse de la pire panne de lien. Peer reviewed
Abstract
This paper presents the software architecture of a traffic engineering toolbox. The methods already included cover MPLS-based intra-domain traffic engineering (TE), but will [...]
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A Preliminary Analysis of the Evolution of US Air Transportanion Network
D. Bhadra, C. Avenue, B. Hogan

Collection of open conferences in research transport (2005). Vol. 2005, 116

Abstract
How does the air traffic network evolve over time? Is there any pattern to how the air traffic network evolves with respect to the size of the markets, type of competition, geospatial features, and structural changes following the events of September 11, 2001 (9/11)? Are the changes transitory or permanent in nature? Can we lay out the trajectory possibilities of the network and determine factors influencing them? The National Airspace System (NAS) in the United States US) is structured primarily around a web of air transportation markets linked to each other through a network of 465 commercial airports located in and around 363 metropolitan statistical areas (MSAs). The total number of origin-destination (OD a small number of markets account for the largest number of passengers and, hence, air traffic flows. For example, there were approximately 105 markets (0.3% of the total) which had 1,000 or more passengers a day (i.e., thick markets), but these accounted for almost 17% of the total passengers. On the other hand, there were almost 28,000 markets (78% of the total) with 10 or fewer passengers a day that accounted for only 6% of total passengers in 2003. These O&D market pairs have been served, generally speaking, by 52,000 − 56,000 flight segments (i.e., routings passengers took to travel the markets) depending upon the extent and intensity of network. In recent years, however, the network segments have increased sizably to an average of 67,000 − 72,000 segments leading to increased fragmentation. 1 Understanding the evolutionary nature of the airline network is extremely important. Investment decisions with consequences stretching far into the future are being made to serve the airline network. A proper understanding of the dynamic nature of the airline network, therefore, is essential to minimize costly mistakes. We used a multinomial logit model to analyze and determine itinerary choices in the US scheduled airline industry. Using 10% ticket sample data for the second quarter of 2003, we find that passengers, weighted average fare, average distance and types of air carriers empirically determine the itinerary choices. This simple model captures lower-order itinerary choices (i.e., those with less than three stops) fairly well for the sample of almost 360,000 itineraries.
Abstract
How does the air traffic network evolve over time? Is there any pattern to how the air traffic network evolves with respect to the size of the markets, type of competition, [...]
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The concept of remote maintenance monitoring and its computer architecture
L. Bottino, W. Hughes

Collection of open conferences in research transport (2005). Vol. 2005, 115

Abstract
The concept of remote maintenance monitoring (RMM) was developed and introduced in industrial engineering as a means to measure the performance. This concept has been studied, evaluated, implemented and deployed by the Federal Aviation Administration (FAA). The application of RMM has improved the maintenance and performance of ground-based navigational aids, weather-related systems, radar surveillance and environmental control systems. Hundreds of FAA air traffic control (ATC) facilities, airports and remote monitoring stations throughout the country employ some sort of RMM. Reliability, suitability, and longevity of navigational aids, weather processors, and surveillance systems have improved due to the functionalities RMM systems provide. Site-specific needs of some of these ATC facilities are due to geographical location and the surrounding environment. RMM computer architecture and computer communication methods are discussed and analyzed. This discussion centers on a successfully deployed RMM sub-system for a weather-related system, an environmentally controlled monitoring system and a ground-based surveillance system. In the end, a sincere attempt is made to demonstrate the success of RMM technology implementation, showcase the benefits and progress towards a versatile open systems approach and present the economic feasibility of this technology with a view towards the future.
Abstract
The concept of remote maintenance monitoring (RMM) was developed and introduced in industrial engineering as a means to measure the performance. This concept has been studied, [...]
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Two approaches to internet traffic engineering for end-to-end quality of service provisioning
K. Ho, G. Pavlou, N. Wang, M. Howarth, S. Georgoulas

Collection of open conferences in research transport (2005). Vol. 2005, 114

Abstract
This paper considers traffic engineering (TE) for the provision of end-to-end quality of service (QoS) guarantees across multiple autonomous systems (ASes) in the Internet. We review an inter-AS QoS management model, and consider algorithms for offline inter-AS and intra-AS TE. We consider two approaches, decoupled and integrated, to allow these systems to work together to achieve optimal TE performance. We quantify through simulation the lower TE costs incurred by the integrated approach.
Abstract
This paper considers traffic engineering (TE) for the provision of end-to-end quality of service (QoS) guarantees across multiple autonomous systems (ASes) in the Internet. [...]
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Improving survivability through traffic engineering in MPLS networks
M. Amin, M. Howarth, K. Ho, G. Pavlou

Collection of open conferences in research transport (2005). Vol. 2005, 113

Abstract
The volume of higher priority Internet applications is increasing as the Internet continues to evolve. Customers require quality of service (QoS) guarantees with not only guaranteed bandwidth and delay but also with high availability. Our objective is for each estimated traffic flow to find a primary path with improved availability and minimum failure impact while satisfying bandwidth constraints and also minimizing network resource consumption. We devise a heuristic algorithm with four different cost functions to achieve our objective. Our approach can enhance availability of primary paths, reduce the effect of failure and also reduce the total resource consumption for both primary and backup paths.
Abstract
The volume of higher priority Internet applications is increasing as the Internet continues to evolve. Customers require quality of service (QoS) guarantees with not only [...]
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Deicing decision support tool
S. Chen, A. Daskalakis, J. Lee

Collection of open conferences in research transport (2005). Vol. 2005, 112

Abstract
With today's highly coupled flight schedules, any disturbance to the schedule of a flight could have unforeseen impact on the downstream connecting flights. Thus, it is crucial to be able to minimize the effects of the various potential disturbances. Deicing is one such disturbance. During the winter months, deicing procedures associated with snowstorms can cause unexpected delays in the flight schedules. Due to the nonlinear nature of the total time associated with the deicing process (which we call the 'total system time', and includes time of waiting and deicing), it is difficult to predict accurately when an aircraft will complete the deicing process. It is difficult, therefore, to predict how the deicing process will influence the subsequent chain of events. In this paper, a queuing model for the deicing process was developed to assist dispatchers to have a more accurate prediction of the completion time for deicing. Moreover, the two major deicing pads at Detroit Metropolitan Wayne County Airport (DTW) were modeled. Through Monte Carlo simulation, estimates of the total system time for the two deicing pads were derived, along with the corresponding 95% confidence intervals. The simulation results were compared to the historical data in the dynamic runway occupancy measurement system (DROMS), which contains DTW surface surveillance and other aviation related data since October 2002. A decision support tool (DST) was developed, displaying the time estimates. With this deicing DST, airline dispatchers or air traffic controllers can send the next outbound flight to the deicing pad with the least amount of total system time, and, therefore, reduce potential disturbances associated with deicing.
Abstract
With today's highly coupled flight schedules, any disturbance to the schedule of a flight could have unforeseen impact on the downstream connecting flights. Thus, it is crucial [...]
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Safety management systems - new wine, old skins
S. Smith

Collection of open conferences in research transport (2005). Vol. 2005, 110

Abstract
This paper presents safety management systems (SMS) in Federal Aviation Administration (FAA). While safety is always a primary concern at the FAA, SMS formalizes the safety risk management policies at the Administration and introduces a plan to strengthen the safety culture and safety training of its employees. Changes in the current system, either new introductions of technology or enhancements of current operations, will be subject to a strict safety risk assessment methodology. Risks will be identified, prioritized, and then mitigated. Data will be collected and monitored to ensure the system maintains or improves the level of safety before the change. The six part safety risk management system coupled with continuous monitoring will strengthen the existing new system development process and bring a formalized process to the operations and maintenance procedures. It will truly bring new wine into old skins.
Abstract
This paper presents safety management systems (SMS) in Federal Aviation Administration (FAA). While safety is always a primary concern at the FAA, SMS formalizes the safety [...]
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Traffic Flow Management Modeling and Operational Complexity
L. Wojcik, B. Hogan

Collection of open conferences in research transport (2005). Vol. 2005, 109

Abstract
Traffic flow management (TFM) actions are commonly used to mitigate capacity/demand imbalances within the National Airspace System (NAS). Modeling TFM events has proven challenging in the past, partly because of weather forecast uncertainty, and partly because of the complexity and unpredictability associated with highly-interrelated traffic patterns and distributed decision-making in the NAS. In this paper, we present results of a simulation of a NAS TFM event in which weather effects are relatively small. This facilitates interpretation of the similarities and differences between simulation results and the actual event in terms of NAS operations and decision making, with relatively small weather-related complications. We conclude that TFM modeling shows promise as a tool to aid post-event TFM analysis, but the complex operational factors impose limits on the predictability of outcomes in TFM events. A CAASD-developed fast-time network simulation of the NAS was used for this analysis.
Abstract
Traffic flow management (TFM) actions are commonly used to mitigate capacity/demand imbalances within the National Airspace System (NAS). Modeling TFM events has proven challenging [...]
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Combined Model for Congestion Control
O. Popov, I. Popova, N. Van

Collection of open conferences in research transport (2006). Vol. 2006, 113

Abstract
The growth of multimedia applications on the Internet made at least one fifth of the total network traffic to run over UDP. Unlike TCP, UDP is unresponsive to network congestion. This may cause, inter alia, bandwidth starvation of responsive flows, severe and prolonged congestions or, in the worst-case scenario, a congestion collapse. Hence, the coexistence of both protocols on fair-share premises converges towards impossibility. The paper deals with a new approach to solving the problem of taming down the unresponsive flows. By using some of the desirable properties of mobile agents, the system is able to control the influx of non-TCP or unresponsive flows into the network. Various functions performed by mobile agents monitor non-TCP flows, calculate sending rates and modify their intensity according to the needs of the network to attain as good performance as it is possible.
Abstract
The growth of multimedia applications on the Internet made at least one fifth of the total network traffic to run over UDP. Unlike TCP, UDP is unresponsive to network congestion. [...]
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Status of the U.S. NAVY CNS/ATM team efforts
G. Sickle, D. Stroup, S. Frain

Collection of open conferences in research transport (2005). Vol. 2005, 108

Abstract
This paper reports on the current status of the PMA-209, Air Combat Electronics (CNS/ATM) team activities. The team has completed the development of the Functional Requirements Documents that convert civil documents prepared by the International Civil Aviation Organization (ICAO), Federal Aviation Administration (FAA), and other Civil Aviation Authorities plans to implement air traffic architecture to meet this need. Our team is taking advantage of emerging technologies in communications, navigation, and surveillance to improve air traffic management. The CNS/ATM requirements for voice, data link, navigation, and surveillance are being met by integration into legacy and new USN/USMC platforms. This paper discuss the issues and program status of the current CNS/ATM efforts for the P-3C, EA-6B, F/A-18 E/F and other platforms; CNS/ATM as it applies to network centric warfare utilizing a digital cockpit for precision strike, common operational picture, improved situational awareness and operational effectiveness. Multiple data links that are required for joint and coalition operations such as Link 16, Mode 5 and CLIP discussed.
Abstract
This paper reports on the current status of the PMA-209, Air Combat Electronics (CNS/ATM) team activities. The team has completed the development of the Functional Requirements [...]
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The Impact of Information Technologies on Air Transportation
R. Hansman

Collection of open conferences in research transport (2005). Vol. 2005, 107

Abstract
The Air Transportation System and several key subsystems including the Aircraft, Airline, and Air Trmc Management are modeled as interacting control loops. The impact of Information Technologies on each of these subsystems is evaluated through the performance of these control loops. Information technologies are seen to have a significant impact on the safety, efficiency, capability, capacity, environmental impact and financial performance of the Air Transportation System and its components. This growth in traffic has been accompanied by an increase in safety and cost efficiency. The world commercial jet aircraft fatal or hull loss accident rate decreased by a factor of 5 from 1972 to 2002 and by more than 25 from the entry of commercial jet aircraft in the early 1960's.~ Cost efficiency has also increased. The average Cost per Available Seat Mile (CASM) for U.S. Airlines has decreased by over 40% since the late 1970's.~ It is interesting to note that this period of strong air transportation performance correlates with both the deregulation of the U. S Airline Industry in 1978 and the growth in Information Technologies. The commercial introduction of the microprocessor was in 197 1 and the introduction of the Intel 8086 processor (which powered most personal computers) occurred in 1978 (Ref. 4) the year the US Auline industry was deregulated. This paper explores the impact of Information Technologies on Air Transportation and attempts to identify key Information Technology trends emergent issues and future opportunities for Air Transportation. In order to limit it's scope, this papa will focus primarily on Information Technologies that influence operational closed loop feedback control at various levels. It w~ll not address Information Technologies such as CFD and computational modeling which have had a significant impact on vehicle design.
Abstract
The Air Transportation System and several key subsystems including the Aircraft, Airline, and Air Trmc Management are modeled as interacting control loops. The impact of Information [...]
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Perception of the fairness of pricing
S. Souche, C. Raux

Collection of open conferences in research transport (2006). Vol. 2006, 109

Abstract
en CD; International audience; Regulation by means of price in order to remove excess demand is generally perceived as being unfair. This paper empirically tests different principles of regulation including lotteries, rationing, a moral rule and compensation."br /"We start from the postulate that the perception of the fairness of a urban road pricing policy is important for a successful implementation. This perception is analysed through the results of an attitudinal survey held in Lyons area in 2003 (N 400). We confirm that peak-period pricing as a means of limiting demand is overwhelmingly rejected. Administrative allocation and lotteries are also rejected. The reference transaction can also lead to rejection of waiting line. Price compensation is overwhelmingly considered to be fair and the right to this is demanded both from public or private sector monopoly: it is possible therefore to reinstate pricing in the form of compensation."br /"Those surveyed express rather definite preferences for some principles of regulation (moral rule, compensation) to the detriment of pricing or even the administrative or traditional regulation (queuing). Ways of unfreezing the situation are identified, who could be exploited in order to form coalitions likely to support this kind of policy. Finally, certain dimensions of the equity are revealed through the analysis of the survey.
Abstract
en CD; International audience; Regulation by means of price in order to remove excess demand is generally perceived as being unfair. This paper empirically tests different [...]
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Simulating Airspace Redesign for Arrivals to Detroit-Wayne County Airport (DTW)
J. Boesel, D. Bodoh

Collection of open conferences in research transport (2005). Vol. 2005, 106

Abstract
In 2001, Detroit Metropolitan Wayne County Airport (DTW) opened a new runway parallel to three existing runways. While this increases DTW's runway capacity, the airport is served by an airspace (routes, procedures, and controller assignments) that was designed only for a three-runway airport. To increase the airport's effective capacity, the Detroit-area terminal radar approach control facility (D21 TRACON) and nearby air route traffic control centers (ARTCC) are redesigning their airspace. This paper describes the simulation modeling effort to estimate delay and cost benefits of the ARTCC redesign for arrival traffic. The model, written in the SLX simulation language, represents miles-in-trail (MIT) restrictions, as well as air traffic controllers' ability to direct flights to different paths dynamically, based on predicted demand downstream. The redesign work is part of the Federal Aviation Administration's Midwest airspace capacity enhancement (MACE) project.
Abstract
In 2001, Detroit Metropolitan Wayne County Airport (DTW) opened a new runway parallel to three existing runways. While this increases DTW's runway capacity, the airport is [...]
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Monte Carlo Optimization Strategies for Air-Traffic Control
W. Glover, J. Maciejowski, J. Lygeros, A. Lecchini

Collection of open conferences in research transport (2005). Vol. 2005, 105

Abstract
The safety of the igh ts, and in particular conict resolution for separation assurance, is one of the main tasks of Air Trac Control. Conict resolution requires decision making in the face of the considerable levels of uncertainty inherent in the motion of aircraft. We present a Monte Carlo framework for conict resolution which allows one to take into account such levels of uncertainty through the use of a stochastic simulator. A simulation example inspired by current air trac control practice illustrates the proposed conict resolution strategy.
Abstract
The safety of the igh ts, and in particular conict resolution for separation assurance, is one of the main tasks of Air Trac Control. Conict resolution requires decision making [...]
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Development of a Sense and Avoid System
J. McCalmont, M. Deschenes, J. Utt

Collection of open conferences in research transport (2005). Vol. 2005, 104

Abstract
Remotely Operated Aircraft (ROAs) currently do not have convenient access to civil airspace due to their inability to provide an onboard capability to “see and avoid” air traffic. Defense Research Associates, Inc. and AFRL/SNJT have developed affordable technology based on silicon charge couple device sensors and passive moving target detection algorithms. Previously, a flight demonstration proved real-time implementation of complex detection and tracking algorithms with multiple sensors providing a wide field of regard was feasible. This paper documents lessons learned from that demonstration, subsequent improvements made to the prototype system, resulting performance improvements, and planned next steps .
Abstract
Remotely Operated Aircraft (ROAs) currently do not have convenient access to civil airspace due to their inability to provide an onboard capability to “see and avoid” [...]
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Mapping lessons from ants to free flight: an ant-based weather avoidance algorithm in free flight airspace
P. Lindsay, H. Abbass, S. Alam, M. Barlow

Collection of open conferences in research transport (2005). Vol. 2005, 103

Abstract
The continuing growth of air traffic worldwide motivates the need for new approaches to air traffic management that are more flexible both in terms of traffic volume and weather. Free Flight is one such approach seriously considered by the aviation community. However the benefits of Free Flight are severely curtailed in the convective weather season when weather is highly active, leading aircrafts to deviate from their optimal trajectories. This paper investigates the use of ant colony optimization in generating optimal weather avoidance trajectories in Free Flight airspace. The problem is motivated by the need to take full advantage of the airspace capacity in a Free Flight environment, while maintaining safe separation between aircrafts and hazardous weather. The experiments described herein were run on a high fidelity Free Flight air traffic simulation system which allows for a variety of constraints on the computed routes and accurate measurement of environments dynamics. This permits us to estimate the desired behavior of an aircraft, including avoidance of changing hazardous weather patterns, turn and curvature constraints, and the horizontal separation standard and required time of arrival at a pre determined point, and to analyze the performance of our algorithm in various weather scenarios. The proposed Ant Colony Optimization based weather avoidance algorithm was able to find optimum weather free routes every time if they exist. In case of highly complex scenarios the algorithm comes out with the route which requires the aircraft to fly through the weather cells with least disturbances. All the solutions generated were within flight parameters and upon integration with the flight management system of the aircraft in a Free Flight air traffic simulator, successfully negotiated the bad weather.
Abstract
The continuing growth of air traffic worldwide motivates the need for new approaches to air traffic management that are more flexible both in terms of traffic volume and weather. [...]
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Routing and traffic engineering in hybrid RF/FSO networks
A. Kashyap, M. Shayman

Collection of open conferences in research transport (2005). Vol. 2005, 102

Abstract
We provide a routing framework for hybrid RF/FSO backbone networks, utilizing the characteristics of RF and free space optical (FSO) links. FSO links offer higher bandwidth and security, while RF links offer more reliability. We propose the concept of criticality index for different classes of traffic and providing obscuration-tolerant paths to the traffic in a weighted max-min fair way. We provide an optimal algorithm for the case where a traffic demand can be routed along multiple paths. The problem of routing unsplittable traffic is NP-hard, so we propose efficient heuristics for routing them. We do extensive simulations to demonstrate that our algorithms outperform the algorithms currently in use.
Abstract
We provide a routing framework for hybrid RF/FSO backbone networks, utilizing the characteristics of RF and free space optical (FSO) links. FSO links offer higher bandwidth [...]
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Improving efficiency of departure release for en route overhead traffic flow management
P. Thompson, P. Kopardekar, S. Green

Collection of open conferences in research transport (2005). Vol. 2005, 101

Abstract
Departures from some airports have to receive an approval by traffic management coordinators before their release. Such approvals are necessary to ensure that the departing aircraft will be accommodated in the overhead stream, which may have a miles-in-trail or some other traffic flow management restriction. Presently, such approvals are received by voice communications between tower controllers and traffic management coordinators. However, under busy periods, multiple tower controllers wait to talk to the traffic management coordinator. Such waiting time and the actual communications time to obtain the clearance create inefficient operations for both tower controllers and traffic management coordinators. This paper presents a proposed capability for electronic communications between the tower controllers and en route traffic management coordinators. This capability reduces the waiting and communications time between the tower controllers and traffic management coordinators.
Abstract
Departures from some airports have to receive an approval by traffic management coordinators before their release. Such approvals are necessary to ensure that the departing [...]
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Refinement Maps for Efficient Verification of Processor Models
P. Manolios, S. Srinivasan

Collection of open conferences in research transport (2005). Vol. 2005, 100

Abstract
Submitted on behalf of EDAA (http://www.edaa.com/); International audience; While most of the effort in improving verification times for pipeline machine verification has focused on faster decision procedures, we show that the refinement maps used also have a drastic impact on verification times. We introduce a new class of refinement maps for pipelined machine verification, and using the state-of-the-art verification tools UCLID and Siege we show that one can attain several orders of magnitude improvements in verification times over the standard flushing-based refinement maps, even enabling the verification of machines that are too complex to otherwise automatically verify.
Abstract
Submitted on behalf of EDAA (http://www.edaa.com/); International audience; While most of the effort in improving verification times for pipeline machine verification has [...]
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Installing and Operating Underground Power Distribution by Sharing Existing Pipelines, Tunnels, and Rights of Way
J. Jeyapalan

Collection of open conferences in research transport (2005). Vol. 2005, 99

Abstract
Many countries have long had the desire to move their overhead power lines to the underground due to increasing pressure from environmentalists, increasing pressure from city planners, losses from frequent outage, loss from bad weather, high cost of maintenance, high transmission loss, electrocution, bushfire risks, high greenhouse emission, auto accidents, cost of tree pruning, better aesthetics, and better real estate value. Cost and the underground already being so crowded with water pipes, sewers, storm drains, gas mains, telephone cables, and other conduits have prevented the power companies from realizing this goal. While the power industry has felt this way, the communications industry is fighting for its survival. It appears these two industries could work together for both of them to gain. Deployment of optical fiber networks or power distribution networks underground in dedicated conduits requires extensive construction, usually involving excavation of city streets. It makes all the sense in the world to locate the power distribution cables and the fiber cables in the existing rights of way on sewers, water mains, gas pipes, tunnels, and other underground structures to move them underground quicker and at a cheaper cost. This paper provides an account of how to go about deploying power and fiber cables either inside or outside of existing utility pipes using trenchless technologies. Tokyo, Taipei, Berlin, Hamburg, Paris, Toronto, Vienna, Boston, New York, Albuquerque, and Indianapolis, are among the growing list of progressive cities where such creative business partnerships have produced unprecedented financial results to all parties concerned. An overview of details of such creative business partnerships where the same existing conduits were used toward win-win situations for all parties involved around the world will be presented along with the results of a global survey of underground power distribution practices. Standardization efforts and workable solutions to technical problems also are given.
Abstract
Many countries have long had the desire to move their overhead power lines to the underground due to increasing pressure from environmentalists, increasing pressure from city [...]
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Analysis of the Transient Cooldown of Sub-Sea Pipelines
A. Nieckele, L. Azevedo, J. Escobedo

Collection of open conferences in research transport (2006). Vol. 2006, 108

Abstract
precise analysis of the transient cooldown of subsea pipelines is crucial for offshore flow assurance, to avoid, for example, hydrate formation or wax deposition. Flow assurance in transportation lines, where column separation can occur due to large temperature drop coupled with large pressure drop, must also be addressed. Usually, pipeline thermal insulation is designed for steady state conditions. However, during shutdowns, the temperature drop experienced by the stagnant fluid is more pronounced, eventually reaching some critical temperature level, that can lead to flow line blockage and flow re-start problems. Thus, the determination of the temperature and pressure distributions along the pipeline under transient conditions is important to maintain the line operating safely. To determine the transient heat transfer in pipelines, the fluid flow conservation equations coupled with the heat conduction equation applied to the pipeline wall were numerically solved. The heat loss from the pipeline was determined by solving the transient heat conduction equation for the pipewall layers, utilizing a simple one-dimensional model in the radial direction. The coupled system was solved numerically employing the finite difference method. Transient analyses were performed for two scenarios. In the first one, the cooldown process of oil in a subsea pipeline was evaluated, with the effect of variable thermal properties on the temperature profile being investigated. The dependence of the temperature on the thermal conductivity and specific heat capacity was analyzed. In the second scenario, gas flows inside the pipeline, and the effect of temperature variation on a stagnant fluid is presented. Tests for different values of thermal diffusivity corresponding to new and old thermal insulations were performed.Copyright © 2006 by ASME
Abstract
precise analysis of the transient cooldown of subsea pipelines is crucial for offshore flow assurance, to avoid, for example, hydrate formation or wax deposition. Flow assurance [...]
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Programming Wireless Sensor Networks with Logical Neighborhoods
L. Mottola, G. Picco

Collection of open conferences in research transport (2006). Vol. 2006, 107

Abstract
Wireless sensor network (WSN) architectures often feature a (single) base station in charge of coordinating the application functionality. Although this assumption simplified the path to adoption of WSN technology, researchers are now being attracted by more decentralized architectures with multiple sinks and heterogeneous nodes. These scenarios are brought to an extreme in Wireless Sensor and Actor Networks (WSANs), where sensing and acting nodes collaborate in a decentralized fashion to implement complex control loops. In these settings, new programming abstractions are required to manage complexity and heterogeneity without sacrificing efficiency.In this paper we propose and define a logical neighborhood programming abstraction. A logical neighborhood includes nearby nodes that satisfy predicates over their static (e.g., type) or dynamic (e.g., sensed values) characteristics. The span of the neighborhood and the definition of its predicates are specified declaratively, along with requirements about the cost of the communication involved. Logical neighborhoods enable the programmer to "illuminate" different areas of the network according to the application needs, effectively replacing the physical neighborhood provided by wireless broadcast with a higher-level, application-defined notion of proximity.This paper presents the definition of a declarative language for specifying logical neighborhoods, highlighting its expressiveness, flexibility and simplicity. Moreover, although the language constructs are readily implemented using existing communication mechanisms, we briefly report about a novel routing scheme we expressly designed to support efficiently our abstractions.
Abstract
Wireless sensor network (WSN) architectures often feature a (single) base station in charge of coordinating the application functionality. Although this assumption simplified [...]
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Differential Flatness and Flight Guidance : A Neural Adaptive Approach
K. Achaibou, W. Lu, F. Mora-Camino

Collection of open conferences in research transport (2005). Vol. 2005, 98

Abstract
Increasing air traffic density as well as new strict environmental regulations make necessary to develop more advanced guidance systems for civil transportation aircraft since complex manoeuvres may appear necessary to meet the corresponding safety, efficiency and environmental constraints. In this paper, a flatness-based guidance control scheme is proposed to fulfil this objective. From the point of view of flatness theory, flight guidance dynamics are shown to be implicit differentially flat with respect to the inertial position of an aircraft. To overcome the numerical difficulty implied by the implicit character of this flatness property, artificial neural networks are introduced to capture the differential relationship between flat outputs and guidance directives which can be submitted to the autopilot so that the aircraft is able to perform complex trajectories. Additional adaptive capability appears necessary to compensate for model approximations, disturbances and neural network limitations.
Abstract
Increasing air traffic density as well as new strict environmental regulations make necessary to develop more advanced guidance systems for civil transportation aircraft since [...]
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Generic Pipelined Processor Modeling and High Performance Cycle-Accurate Simulator Generation
M. Reshadi, N. Dutt

Collection of open conferences in research transport (2005). Vol. 2005, 97

Abstract
Detailed modeling of processors and high performance cycle-accurate simulators are essential for today's hardware and software design. These problems are challenging enough by themselves and have seen many previous research efforts. Addressing both simultaneously is even more challenging, with many existing approaches focusing on one over another. In this paper, we propose the Reduced Colored Petri Net (RCPN) model that has two advantages: first, it offers a very simple and intuitive way of modeling pipelined processors; second, it can generate high performance cycle-accurate simulators. RCPN benefits from all the useful features of Colored Petri Nets without suffering from their exponential growth in complexity. RCPN processor models are very intuitive since they are a mirror image of the processor pipeline block diagram. Furthermore, in our experiments on the generated cycle-accurate simulators for XScale and StrongArm processor models, we achieved an order of magnitude (~15 times) speedup over the popular SimpleScalar ARM simulator. Comment: Submitted on behalf of EDAA (http://www.edaa.com/)
Abstract
Detailed modeling of processors and high performance cycle-accurate simulators are essential for today's hardware and software design. These problems are challenging enough [...]
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A Reactive Control Approach for Pipeline Inspection with an AUV
L. Lapierre, P. Paim, B. Jouvencel

Collection of open conferences in research transport (2005). Vol. 2005, 96

Abstract
International audience; Recent technological advances and the growing demands for underwater operations suggest that autonomous underwater vehicles will become increasingly present in com- mercial and research activities, performing tasks such as survey, inspection of sub-sea pipelines and object recovery. This fact calls for the development of guidance and control algorithms for the execution of this kind of mission. This paper proposes a reactive control approach for pipeline following by a torpedo- like autonomous underwater vehicle. The method presented here, called the Deformable Virtual Zones (DVZ) method was originally conceived at the LIRMM for obstacle avoidance by mobile robots and AUVs. It consists of the modelling of a virtual zone around the robot, whose configuration depends on the robots states. The intrusion of proximetric information in this zone inflicts a deformation, and the control signal is computed so that the robot will react in order to minimise this deformation. We extend this sensor-based control method by proposing a new DVZ configuration for pipeline following by an autonomous underwater vehicle. Simulation results allow verifying its robustness as the pipeline changes direction, taking into account AUV dynamics. The proposed method is currently being implemented using the TAIPAN II, a small sized torpedo- like AUV developed at the LIRMM, fitted with a profiling sonar system. Experimental results will soon be available.
Abstract
International audience; Recent technological advances and the growing demands for underwater operations suggest that autonomous underwater vehicles will become increasingly [...]
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A Monocular Vision Advance Warning System for the Automotive Aftermarket
I. Gat, A. Shashua, M. Benady

Collection of open conferences in research transport (2005). Vol. 2005, 95

Abstract
Driver inattention and poor judgment are the major causes of motor vehicle accidents (MVA). Extensive research has shown that intelligent driver assistance systems can significantly reduce the number and severity of these accidents. The driver’s visual perception abilities are a key factor in the design of the driving environment. This makes image processing a natural candidate in any effort to impact MVAs. The vision system described here encompasses 3 major capabilities: (i) Lane Departure Warning (ii) Headway Monitoring and Warning (iii) Forward Collision Warning. This paper describes in detail the different warning features, the HMI (visual and acoustic) application design rules, and results of a study in which the system was installed in a commercial fleet and passenger vehicles.
Abstract
Driver inattention and poor judgment are the major causes of motor vehicle accidents (MVA). Extensive research has shown that intelligent driver assistance systems can significantly [...]
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Experimental evaluation of portable electronic flight progress strips
N. Doble, R. Hansman

Collection of open conferences in research transport (2005). Vol. 2005, 94

Abstract
traffic service providers are increasingly embracing electronic alternatives to the traditional paper flight progress strip (FPS). However, most development of such electronic systems, and of decision support tools (DSTs) in general, has centered on radar-based en route or terminal-area facilities, rather than the airport air traffic control tower. Based on an analysis of the unique human factors requirements of the control tower environment, a prototype portable electronic FPS has been designed that also serves as an interface to a DST for departure operations. The portable electronic FPS has been implemented using a system of networked, handheld computers as prototype hardware. A study has been conducted to evaluate the usability of the portable electronic FPS. The study consisted of a human-in-the-loop experiment that simulated the tasks an air traffic controller performs at a major airport. Three issues were explored: the importance of FPS portability, the appropriateness of departure sequence DST advisories distributed onto each portable electronic FPS, and the advantages of interaction mechanisms enabled by an electronic interface. Test subjects used multiple versions of the portable electronic FPS as well as a current-day paper FPS. Quantitative measures of departure sequencing efficiency and traffic monitoring ability were recorded for each test subject, as well as subjective FPS preference rankings. This paper reviews the final design and prototype implementation of the portable electronic FPS, presents the design and results of the usability study, and suggests future research that should be pursued in order to create an operationally deployable portable electronic FPS system.
Abstract
traffic service providers are increasingly embracing electronic alternatives to the traditional paper flight progress strip (FPS). However, most development of such electronic [...]
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A Principal Components Model Of Simulation Structure
D. Grier

Collection of open conferences in research transport (2005). Vol. 2005, 93

Abstract
It is often appropriate to analyze the output of a simulation study by looking at more than one measurement. In a traditional queuing model, it might be appropriate to look at three outputs:1. the average time through the system for a customer,2. the average number of balks per hour,3. the average utilization of the servers.These outputs measure different quantities which are usually related in their movements. Some pairs will be positively related, in that one variable will increase as the other variable increases. Likewise some will be negative related. The relationship can also be more complicated. For example, a recent simulation of a mining operation (Villanueva, 1989) measured, among other quantities, the amount of traffic in a mine tunnel leading to an ore shaft and the number of loads of ore removed through that shaft per hour. Initially, as the traffic increased, more loads of ore were removed. But as the tunnel became more and more crowded, the number of loads began to drop because of the traffic congestion.
Abstract
It is often appropriate to analyze the output of a simulation study by looking at more than one measurement. In a traditional queuing model, it might be appropriate to look [...]
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Human factors in the design and development of an advanced decision support tool
R. Lanier, R. Coppenbarger

Collection of open conferences in research transport (2005). Vol. 2005, 92

Abstract
Human Factors concerns must be integrated in the design and development of automation to assist air traffic management efficiency and safety in future traffic systems. This paper describes the practices used in development of an advanced decision support tool (DST) for addressing and resolving the human performance and information processing requirements. The en route descent advisor (EDA) is an advanced DST that assists controllers with metering of arrival aircraft in transition from Center to TRACON airspace. EDA generates comprehensive control advisories, allowing for efficient traffic control and compliance with metering and separation requirements. In today's environment controllers must rely entirely on their skill and judgment to provide instructions for conformance to flow rate restrictions and conflict avoidance. Automation that allows accurate, efficient ground-based control of the transition and descent phase of flight will result in a reduction in workload, flight deviations, and fuel consumption. A fundamental criterion for successful development of an advanced DST must be the acceptance and trust in the tool for use in an operational environment. The DST must provide a functional reduction in the controller's workload during periods of intense traffic demands, as well as during normal flow conditions. For use in traffic control, the DST must be accurate, stable, and efficient in all possible applications. Achieving these fundamental human factors design goals requires a dedicated focus on development of robust and versatile algorithms and the underlying processes that support the DST functions. Since EDA is still in the concept development phase, the project presents a unique opportunity for early and continuous human factors involvement throughout the development and evaluation cycle. To address these human factors concerns, simulation, testing and validation are performed as an integral part of the overall EDA development activity. The incremental process for EDA development permits controller evaluations and recommendations to be included in the development of the mature DST capabilities. This paper discusses controller-in-the-loop trials for development of trajectory visualization and other information presentations.
Abstract
Human Factors concerns must be integrated in the design and development of automation to assist air traffic management efficiency and safety in future traffic systems. This [...]
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Challenges in imaging shallow high resolution seismic data
D. Henley

Collection of open conferences in research transport (2005). Vol. 2005, 91

Abstract
High resolution seismic methods are increasingly being used to image the shallowest layers of the earth. Objectives include bedrock features, buried cultural structures such as pipelines, and even paleontological or archaeological anomalies. Shallow surveys are often performed under less than ideal conditions, however, and the resulting data may be poor in quality, sparse in fold, and limited in aperture. Furthermore, the elastic properties of near surface earth materials may differ considerably from those of more competent rocks at greater depth, creating further challenges for the imaging process. Presented here are the results of using some unconventional processing techniques to image seismic data constituting two components of a 3-C seismic survey conducted in the vicinity of an archaeological site in Belize during the summer of 2000 in order to locate interesting subsurface features prior to excavation. Useful images were obtained for both P-P reflected and P-S converted modes showing roughly coincident subsurface anomalies; but the raw 3-C data themselves proved to be surprisingly ambiguous, each component manifesting substantial levels of both vertical and inline horizontal particle motion.
Abstract
High resolution seismic methods are increasingly being used to image the shallowest layers of the earth. Objectives include bedrock features, buried cultural structures such [...]
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Fast branch misprediction recovery in out-of-order superscalar processors
S. Onder, P. Zhou, S. Carr

Collection of open conferences in research transport (2005). Vol. 2005, 89

Abstract
Current trends in modern out-of-order processors involve implementing deeper pipelines and a large instruction window to achieve high performance. However, as pipeline depth increases, the branch misprediction penalty becomes a critical factor in overall processor performance. Current approaches to handling branch mispredictions either incrementally roll back to in-order state by waiting until the mispredicted branch reaches the head of the reorder buffer, or utilize checkpointing at branches for faster recovery. Rolling back to in-order state stalls the pipeline for a significant number of cycles and checkpointing is costly.This paper proposes a fast recovery mechanism, called Eager Misprediction Recovery (EMR), to reduce the branch misprediction penalty. Upon a misprediction, the processor immediately starts fetching and renaming instructions from the correct path without restoring the map table. Those instructions that access incorrect speculative values wait until the correct data are restored; however, instructions that access correct values continue executing while recovery occurs. Thus, the recovery mechanism hides the latency of long branch recovery with useful instructions.EMR achieves a mean performance improvement very close to a recovery mechanism that supports checkpointing at each branch. In addition, EMR provides an average of 9.0% and up to 19.9% better performance than traditional sequential misprediction recovery on the SPEC2000 benchmark suite.
Abstract
Current trends in modern out-of-order processors involve implementing deeper pipelines and a large instruction window to achieve high performance. However, as pipeline depth [...]
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Statistical Modeling of Pipeline Delay and Design of Pipeline under Process Variation to Enhance Yield in sub-100nm Technologies
S. Bhunia, K. Roy, N. Banerjee, S. Mukhopadhyay, A. Datta

Collection of open conferences in research transport (2005). Vol. 2005, 88

Abstract
Operating frequency of a pipelined circuit is determined by the delay of the slowest pipeline stage. However, under statistical delay variation in sub-100nm technology regime, the slowest stage is not readily identifiable and the estimation of the pipeline yield with respect to a target delay is a challenging problem. We have proposed analytical models to estimate yield for a pipelined design based on delay distributions of individual pipe stages. Using the proposed models, we have shown that change in logic depth and imbalance between the stage delays can improve the yield of a pipeline. A statistical methodology has been developed to optimally design a pipeline circuit for enhancing yield. Optimization results show that, proper imbalance among the stage delays in a pipeline improves design yield by 9% for the same area and performance (and area reduction by about 8.4% under a yield constraint) over a balanced design. Comment: Submitted on behalf of EDAA (http://www.edaa.com/)
Abstract
Operating frequency of a pipelined circuit is determined by the delay of the slowest pipeline stage. However, under statistical delay variation in sub-100nm technology regime, [...]
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Weld-After-Backfill, A Growing Industry Practice
R. Warner, B. Buchanan, D. Dechant

Collection of open conferences in research transport (2005). Vol. 2005, 87

Abstract
This study documents a series of eight trials of the weld-after backfill (W-A-B) sequence. This sequence of pipeline construction was first used in the late 1980's on a pipeline in Texas. Since then, more than 45 major pipeline projects in the United States have been constructed using W-A-B. These projects included a variety of pipe joint coating materials such as mortar diapers, concrete encasement, tape coatings and heat-shrinkable sleeves. This study focuses on heat-shrinkable sleeves for coating the pipe joint, prior to backfill. A growing practice in steel water pipeline construction entails fitting bell & spigot pipe segments together, installing field joint coatings and backfilling the pipe prior to welding. Welding is then completed from the inside of the pipe after the pipe has been backfilled. Weld-after-backfill has proven to be successful in minimizing the length of open trench, improving project safety and speeding up pipeline laying, resulting in design, economic and safety advantages over traditional steel water pipeline construction methods. These advantages benefit the owner, designer, contractors and suppliers. W-A-B is recommended for projects with lap welded joints, which is the predominant joint design for most water pipeline installations. The welding process, however, produces high temperatures on the pipe wall, which may damage some corrosion coatings. Research by Northwest Pipe, National Welding and Canusa-CPS was completed to evaluate various welding processes, measure temperatures and assess the affects of the W-A-B sequence on exterior field joint coatings. Various heat-shrinkable sleeve-coating systems were tested in order to optimize currect practices. This paper describes the W-A-B sequence, explains typical installation and welding processes, provides data from the research and makes recommendation as to best practices when this construction method is used.
Abstract
This study documents a series of eight trials of the weld-after backfill (W-A-B) sequence. This sequence of pipeline construction was first used in the late 1980's on a pipeline [...]
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Alternative surveillance technology for the Gulf of Mexico
C. Daskalakis, P. Martone

Collection of open conferences in research transport (2005). Vol. 2005, 86

Abstract
In the Gulf of Mexico, there are two major operating aviation users: low altitude offshore and high altitude. The low altitude offshore operators are primarily helicopter fleets supporting the oil and gas exploration efforts; their traffic typically consists of 5,000 to 6,000 flights per day, most less than one hour in duration. In the high altitude regime, over 300 oceanic flights pass through the Gulf of Mexico. Offshore surveillance coverage in the Gulf of Mexico is currently limited due to remote, over-water operations. Implementation of primary or secondary radar to support surveillance coverage in the Gulf of Mexico is technically and economically difficult. Air traffic between the United States and destinations in the Caribbean, Mexico, and Central America has grown at a rate of over 8% per year over the last 12 years. Currently, flights that transit the Central Gulf of Mexico are subjected to oceanic separation standards in part because of a lack of direct pilot-controller communications, standardized aircraft navigation requirements, and limitations to radar surveillance. Air traffic traversing the Gulf of Mexico often must choose between accepting a ground delay, a reroute, or a less fuel-efficient altitude. An estimated 40% of the traffic in the non-radar airspace may not receive their requested altitude or route. However, if seamless surveillance and communication coverage were implemented in the Gulf of Mexico, aircraft separation standards may be reduced from the current oceanic standards to domestic enroute standards, thus reducing delays and improving aircraft safety. To improve surveillance coverage in the Gulf of Mexico for both the low altitude and high altitude users, the National Aeronautics and Space Administration (NASA) has initiated activities leading to deployment of alternative surveillance technology in the offshore area of the Gulf of Mexico. These technologies, multilateration and ADS-B, has significant potential to fill the lack of surveillance in the Gulf of Mexico. NASA conducted previous evaluations of multilateration and ADS-B for the low altitude offshore users recently. These evaluations demonstrated the feasibility of ADS-B and multilateration. NASA, along with the Federal Aviation Administration's (FAA) Safe Flight 21 Program Office are conducting evaluations to determine ADS-B, as well as wide area multilateration, performance over US controlled high altitude airspace in the Gulf of Mexico. To support this evaluation, a network of eight ground stations (Mode S extended squitter) has been installed from Texas to Florida with the Central Processing System located at the Houston ARTCC in Houston, TX. As part of this network, three ground stations have been installed approximately 200 NMI offshore in the Gulf of Mexico. This network provides almost entire coverage of US oceanic airspace in the Gulf of Mexico. Also as part of this evaluation, the network of ground stations provides wide area multilateration coverage as well (where 3 or more ground stations receive an aircraft's transponder reply). The multilateration coverage area provides surveillance for aircraft at FL240 and above. Three flight tests, using the FAA Tech Center's B727 and the NASA Gulfstream III aircraft, were conducted from January to March 2004. The results from these flight tests are presented in this paper, assessing the performance of ADS-B and wide area multilateration in the Gulf of Mexico.
Abstract
In the Gulf of Mexico, there are two major operating aviation users: low altitude offshore and high altitude. The low altitude offshore operators are primarily helicopter [...]
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Analysis of aircraft conflict geometries in Europe
R. Christien, R. Ehrmanntraut

Collection of open conferences in research transport (2005). Vol. 2005, 85

Abstract
Conflict management is a central role of air traffic control. Several projects in the world work on the semi- or full-automation of this function. The understanding of the nature of aircraft conflict is a prerequisite for successful automation. Therefore, it would be useful to update the statistics about aircraft conflicts in Europe, to know where and when they occur, the distribution of attitudes of involved aircraft, of encounter angles, encounter speeds, encounter flight levels, and flight phases at the time of conflict. Of special interest are also statistics about proximities and correlations with other parameters of airspace complexity. The results of the European-wide simulation give new insights into the nature of conflicts. The studies have been conducted with the help of a simulation model. The simulation tool is presented, and the assumptions and conditions of the simulations described. The empirical data is used for a theoretical discussion about uncertainty of conflict prediction.
Abstract
Conflict management is a central role of air traffic control. Several projects in the world work on the semi- or full-automation of this function. The understanding of the [...]
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Implicit intent information for conflict detection and alerting
C. Munoz, V. Carreno

Collection of open conferences in research transport (2005). Vol. 2005, 84

Abstract
Conflict detection algorithms can be broadly classified as state based and intent based algorithms. State based algorithms predict the path of aircraft by projecting their current position and velocity vectors. The path predictions are then used to determine if the aircraft are in conflict within a look ahead time. That is, if loss of separation occurs in the future. Intent based algorithm uses flight plans and other information, which usually resides in a flight management computer, to predict the path of aircraft. Algorithms that use intent information for conflict detection obtain the intent of other aircraft and broadcast their own intent via some type of communication link. Intent information that is exchanged among the aircraft is defined as explicit intent. A conflict detection algorithm can also make use of intent information based on aircraft nominal routes, corridors, published approaches, etc., and in this case, there is no information exchange between aircraft. This kind of intent is defined as implicit intent. Implicit intent can be used very effectively in conflict detection without the added cost and complexity of communication links. The use of implicit intent, in combination with state information, reduces false alarms over a state based conflict detection algorithm and therefore increases the effectiveness of the alerting system. In this paper, conflict detection using implicit intent information is described and its performance is compared with a state based conflict detection algorithm.
Abstract
Conflict detection algorithms can be broadly classified as state based and intent based algorithms. State based algorithms predict the path of aircraft by projecting their [...]
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Validation of a simulation model of the national airspace system
M. Cheslow

Collection of open conferences in research transport (2005). Vol. 2005, 83

Abstract
validation program has been developed to check the accuracy and validity of a simulation model being developed for the Federal Aviation Administration. The program is composed of four components: conceptual model validitation, input data validation, computerized model correctness checks, and operational validation. As part of the operational validation, model output is compared with three aviation delay databases which vary in their definitions and measurement of delay. Therefore, a major part of the validation program has been to determine adjustments that must be made to model output in order to make valid comparisons.
Abstract
validation program has been developed to check the accuracy and validity of a simulation model being developed for the Federal Aviation Administration. The program is composed [...]
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IMT2000 3G terrestrial standards with applications to airport and terminal air traffic communications
M. Shamma

Collection of open conferences in research transport (2005). Vol. 2005, 82

Abstract
The International Mobile Telecommunications IMT2000 terrestrial standards are investigated as a potential alternative for communications to aircraft mobile users in airport and terminal domains. Specifically, its application to air traffic management (ATM) communication needs is considered. The various specifications of the IMT2000 standards are outlined. It is shown via a system research analyses that it is possible to support most air traffic communication needs via the use of 3G technologies. This technology can compliment existing or future digital aeronautical communications technologies such as VHF digital links mode 2, 3, 4 (VDL2, VDL3, VDL4).
Abstract
The International Mobile Telecommunications IMT2000 terrestrial standards are investigated as a potential alternative for communications to aircraft mobile users in airport [...]
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Feasibility of self-separation and sequencing during GPS instrument approaches
J. Murdoch, J. McNabb, E. Ramiscal, F. Bussink

Collection of open conferences in research transport (2005). Vol. 2005, 81

Abstract
The self-separation and sequencing (SSS) flight experiment was conducted by the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) to determine if instrument rated general aviation (GA) pilots could self-separate and sequence their ownship aircraft, while following a simulated aircraft, into a simulated nontowered, nonradar airport during simulated instrument meteorological conditions (IMC). Six GA pilots' subjective workload levels and abilities to fly a Cirrus SR22X aircraft while performing self-separation and sequencing procedures during straight-in, intrail approaches and approaches with simultaneous arrivals of aircraft were examined. This paper discusses the results of the flight experiment and its relevance to future research.
Abstract
The self-separation and sequencing (SSS) flight experiment was conducted by the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) to determine [...]
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Simulation Pipeline Control Systems for Operator Training
D. Basnett

Collection of open conferences in research transport (2006). Vol. 2006, 90

Abstract
Most pipeline simulations are primarily concerned with performance of the pipeline, and the modeler typically assumes an idealized model of the control systems. The modeler assumes that control devices operate instantaneously and perfectly. This assumption is sufficient for a wide range of engineering simulation tasks, but inadequate for simulations used to training pipeline operators. For training purposes it is important that the software provides a “virtual pipeline” that responds in the same manner as the real pipeline. The simulator should model the delays and interactions of the control system as well as the hydraulics of the pipeline. This paper describes how a generic control capability was added to an existing liquid simulation package to provide a more realistic training simulation for several applications including crude oil and multi-product pipelines. The paper will discuss the practical lessons learned from these simulations of the full control systems for pipeline training systems. The potential drawbacks of the method chosen will also be addressed.
Abstract
Most pipeline simulations are primarily concerned with performance of the pipeline, and the modeler typically assumes an idealized model of the control systems. The modeler [...]
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Automation of Human Decision Processes for Route Completion for Airspace Design Analysis
L. Schaefer

Collection of open conferences in research transport (2005). Vol. 2005, 79

Abstract
This paper describes an algorithm for approximating missing data in air traffic routes thereby allowing the lengths of different routes to be compared for our simulation analyses. We were given air traffic routes that had origin, destination, and complete route information inside of the problem design area. Analyst judgment was necessary for completing the routes outside of the design area. We automated the analyst decision processes so that comparisons could be made across scenarios. This process was required for thousands of routes. We analyze design performance measures and show that the resulting distances among the redesigned routes differ from baseline route lengths.
Abstract
This paper describes an algorithm for approximating missing data in air traffic routes thereby allowing the lengths of different routes to be compared for our simulation analyses. [...]
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A Cooperative Distributed Approach to Multi-Agent Eulerian Network Control: Application to Air Traffic Management
R. Raffard, C. Tomlin, A. Bayen, S. Waslander

Collection of open conferences in research transport (2005). Vol. 2005, 78

Abstract
Based on an Eulerian network model, air traffic flow in the National Airspace System is optimized using second order adjoint methods for hyperbolic PDEs. Multiple airlines with independent cost structures are added to previous work on air traffic flow modeling and optimization. A cooperative, distributed solution methodology is proposed that allows airlines to keep cost information private by distributing the computational workload between the airlines while ensuring efficient outcomes. The Nash Bargaining Solution is presented as a possible solution concept, and a distributed method for its calculation is presented. I. Introduction Management of today’s National Airspace System (NAS) has become an extremely complicated task. Pilots and controllers must continuously manage numerous complex subsystems and adapt to frequent changes in traffic flow, spacing and routing caused by variable weather conditions and other network delays. Specifically, the national Air Traffic Control System Command Center (ATCSCC) is responsible for continuously updating decisions concerning traffic flow to maximize network throughput. The current methodology is based on a sophisticated set of rules described in playbooks that have been developed through years of controller experience. This procedure is neither automated nor optimal, and requires constant human intervention to allow the system to operate. Airlines are an integral element of the NAS and are developing more and more advanced methods of aircraft management, as supervised by Airline Operations Centers (AOCs). Their stake in aircraft flow decisions is quite high, as their profitability is directly tied to on-time performance, and significant costs are incurred by flight delays, cancellations and rerouting. Furthermore, their preferences change dynamically, based on highly variable parameters such as aircraft load factor and percentage of connecting passengers per flight. Unfortunately, airlines are currently only able to affect decisions over a small part of the network flow problem, by swapping slots with their own aircraft and deciding which flights to delay when required. For smooth flow of their aircraft over the NAS network, the airlines must rely on the savvy and equity of the ATCSCC controllers who attempt to minimize schedule disruption while not necessarily minimizing incurred costs. This need not be the case. Consider a futuristic scenario for the NAS, where airlines cooperate with each other in a distributed manner, supervised by the FAA, to dynamically reroute and reschedule flights based on restrictions imposed by weather conditions and network delays in such a manner that their individual profits are maximized, while all safety requirements are met and the airspace is used efficiently. In sucha scenario, real-time collaboration amongst the airlines will drive the efficient use of resources by incorporating airline specific preferences between routes into the flow optimization and ultimately, the passenger will be better served.
Abstract
Based on an Eulerian network model, air traffic flow in the National Airspace System is optimized using second order adjoint methods for hyperbolic PDEs. Multiple airlines [...]
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Indifference-zone selection procedures for choosing the best airspace configuration
D. Gray, D. Goldsman

Collection of open conferences in research transport (2005). Vol. 2005, 77

Abstract
We present a real-world application of a ranking and selection procedure for selecting the best of a number of competing systems. We concentrate on an indifference-zone normal means procedure. Our example involves the selection of an airspace configuration which minimizes airspace route delays.
Abstract
We present a real-world application of a ranking and selection procedure for selecting the best of a number of competing systems. We concentrate on an indifference-zone normal [...]
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Control Design and Implementation for the Self-Separation of In-Trail Aircraft
E. Alonso

Collection of open conferences in research transport (2005). Vol. 2005, 76

Abstract
With growing air traffic demands, one proposal to reduce overall controller workload is to delegate responsibility for maintaining separation to the cockpit. One suggested implementation of this concept is a control law that can automatically maintain separation in a string of in-trail aircraft, with, or without pilot intervention or oversight. In this paper we explore the development of control laws that can aid in the maintenance of separation in strings of aircraft. A string of aircraft is assumed to consist of a lead aircraft which is following a nominal route and flight profile. The nominal route includes descent, speed changes and turns. Following aircraft are required to maintain separation from aircraft ahead in the string. Each following aircraft in the string has identical control law. The controller used is based on Proportional-Derivative (PD) action. The effect of feedback from different aircraft is studied to determine the requirements to maintain safe separation. A simulation of an Automatic Dependence Surveillance – Broadcast (ADS-B) signal is used to communicate state vectors between aircraft in the string. The numerical approach was to simulate the dynamics of aircraft within MATLAB using linearized aircraft equations of motion. Using these dynamics, the control law aimed at maintaining the aircraft on their course while maintaining a fixed separation distance. Additional nonlinear logic is added to maintain speed and thrust commands within acceptable limits. The program was then run to test strings of aircraft in descending and turning flight trajectories using several feedback schemes. The results show that the control algorithm and ADS-B transmission to determine state information are sufficient to allow following aircraft to maintain separation in a descending, variable speed string of aircraft. Generally, in a long string of aircraft, feedback of separation from only the immediately preceding aircraft may be insufficient to maintain separation. Further tests are required in a total nonlinear simulation are required to validate these conclusions, to investigate other simulation scenarios, and to optimize the control schemes chosen.
Abstract
With growing air traffic demands, one proposal to reduce overall controller workload is to delegate responsibility for maintaining separation to the cockpit. One suggested [...]
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The interaction of IGP weight optimization with BGP
O. Delcourt, B. Quoitin, S. Cerav-Erbas, B. Fortz

Collection of open conferences in research transport (2006). Vol. 2006, 83

Abstract
Link weight optimization is shown to be a key issue in engineering of IGPs using shortest path first routing. The IGP weight optimization problem seeks a weight array resulting an optimal load distribution in the network based on the topology information and a traffic demand matrix. Several solution methods for various kinds of this problem have been proposed in the literature. However, the interaction of IGP with BGP is generally neglected in these studies. In reality, the optimized weights may not perform as well as expected, since updated link weights can cause shifts in the traffic demand matrix by hot-potato routing in the decision process of BGP. Hot-potato routing occurs when BGP decides the egress router for a destination prefix according to the IGP lengths. This paper mainly investigates the possible degradation of an IGP weight optimization tool due to hot-potato routing under a worst-case example and some experiments which are carried out by using an open source traffic engineering toolbox. Furthermore, it proposes an approach based on robust optimization to overcome the negative effect of hot-potato routing and analyzes its performance
Abstract
Link weight optimization is shown to be a key issue in engineering of IGPs using shortest path first routing. The IGP weight optimization problem seeks a weight array resulting [...]
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Perceptron-Based Branch Confidence Estimation
H. Akkary, Y. Patil, R. Koltur, W. Refaai, S. Srinivasan

Collection of open conferences in research transport (2005). Vol. 2005, 75

Abstract
Pipeline gating has been proposed for reducing wasted speculative execution due to branch mispredictions. As processors become deeper or wider, pipeline gating becomes more important because the amount of wasted speculative execution increases. The quality of pipeline gating relies heavily on the branch confidence estimator used. Not much work has been done on branch confidence estimators since the initial work [6]. We show the accuracy and coverage characteristics of the initial proposals do not sufficiently reduce mis-speculative execution on future deep pipeline processors. In this paper, we present a new, perceptron-based, branch confidence estimator, which is twice as accurate as the current best-known method and achieves reasonable mispredicted branch coverage. Further, the output of our predictor is multi-valued, which enables us to classify branches further as "strongly low confident" and "weakly low confident". We reverse the predictions of "strongly low confident" branches and apply pipeline gating to the "weakly low confident" branches. This combination of pipeline gating and branch reversal provides a spectrum of interesting design options ranging from significantly reducing total execution for only a small performance loss, to lower but still significant reductions in total execution, without any performance loss.
Abstract
Pipeline gating has been proposed for reducing wasted speculative execution due to branch mispredictions. As processors become deeper or wider, pipeline gating becomes more [...]
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Simulation and Evaluation of Freeway Traffic Using Interchangeable Behavioral Models
D. Hartmann, K. Erlemann

Collection of open conferences in research transport (2005). Vol. 2005, 74

Abstract
Microscopic simulation of traffic flow has spawned many different behavioral models, some of them commercially distributed, some developed at academic institutions for scientific purposes. These models are either kept secret (for commercial products) or substantially lacking in terms of usability and visualization. In this paper, we introduce the simulation environment BABSIM that allows for different driving behaviors to be integrated into one common simulation package. An overview of microscopic simulation is given, and several existing models and their implementations are being discussed. The fundamental structure of the BABSIM package, its user interface and the calibration of the model parameters are presented. Introduction The number of motorized vehicles on this planet is steadily increasing, and there is no indication that this trend is going to abate in coming years. The German federal highway network alone consists of about 12100 kilometers of road, with a planned growth of 15 % in the next couple of years (BMVBW, 2004), not counting the inevitable maintenance efforts. To cope with these complex planning tasks, t raffic engineers are increasingly using traffic simulation as a means for effectively evaluating the capacity of new road designs. Numerous established microscopic simulation packages exist for emulating the flow of individual vehicles on a more or less complex road network. Some of these programs are being commercially developed and distributed. As the targeted market segment is relatively small, the competition is rather fierce, and the underlying simulation models are often not disclosed. Such a black-box concept discourages the use of traffic simulation for public road planning projects, as no certified model exists and the validity of simulation results cannot be verified. The project BABSIM, carried out in joint research between the ICE and the Institute for Traffic Engineering at the Ruhr-University, addresses this problem by integrating several well-documented and established car-following and lane-change behaviors into one common simulation environment. Furthermore, the user is enabled to introduce new behavioral strategies to address his specific planning requisites. BABSIM specializes in simulating the traffic on multi-lane freeways, including the complex weaving behaviors in proximity of freeway junctions.
Abstract
Microscopic simulation of traffic flow has spawned many different behavioral models, some of them commercially distributed, some developed at academic institutions for scientific [...]
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Air-sea linkages in European port cities
C. Ducruet, O. Joly, H. Martell Flores

Collection of open conferences in research transport (2005). Vol. 2005, 73

Abstract
This chapter aims at highlighting the relationships between air, maritime & logistic activities of port cities in Europe. Although recent studies have considered sea-air intermodality as a locational advantage for ports and coastal urban centres, they are still few and isolated case studies. Nevertheless, this subject appears to be of growing interest for transport, logistic players and urban planners to improve port performance in a competitive context. However, there is neither an estimation nor a comparative analysis on effective air-sea relations within port city nodes. We propose a valuation of such potentials based on available and comparable data at a European scale, such as air and maritime traffics, urban population, and employment in specific transport activities (freight forwarding, logistics, warehousing, port and airport services). This innovative approach focuses on the level of interdependency between airports, ports and cities. It shows that air-sea linkages within European port cities are still not strongly interdependen
Abstract
This chapter aims at highlighting the relationships between air, maritime & logistic activities of port cities in Europe. Although recent studies have considered sea-air intermodality [...]
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Toward efficient and equitable distributed air traffic flow control
R. Raffard, C. Tomlin, S. Waslander

Collection of open conferences in research transport (2006). Vol. 2006, 79

Abstract
In order to ensure efficient and equitable use of the National Airspace, the problem of air traffic flow control is posed as a PDE constrained optimization program which explicitly incorporates distinct preferences for independent airlines. Novel cost metrics are introduced to capture the real-world cost of delays to the airlines, and control parameters are aligned with the actual inputs the FAA can manipulate in dealing with adverse weather conditions, which include ground-delay programs, miles-in-trail restrictions and flight reroutes. A market mechanism is proposed that allows for distributed computation of efficient and equitable solutions. The resulting solution preferentially reduces delays for expensive flights, but compensates less expensive flights via transfer payments.
Abstract
In order to ensure efficient and equitable use of the National Airspace, the problem of air traffic flow control is posed as a PDE constrained optimization program which explicitly [...]
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Monitoring for Transient Pressures in Pipelines
W. Worthington

Collection of open conferences in research transport (2005). Vol. 2005, 72

Abstract
change in the flow rate in a full pipeline will cause a change in the pressure within that pipeline. These changes are given careful attention in the well-designed pipeline; however, in the past it has been difficult to accurately measure these transient pressures after the pipeline is constructed and placed in service. Transient pressures exceeding the structural strength of the pipeline will cause damage in the form of rupture or, as is more frequently the case, in the form of latent damage that results in failure at a later date. Advances in digital data processing systems have significantly improved our ability to continuously monitor and record even the very-short waterhammer event. These improvements have facilitated monitoring for transient pressures under a wide variety of circumstances. Early detection of damaging transient pressure events is now more practicable, thus permitting the reduction of damage to pipelines resulting from these events.
Abstract
change in the flow rate in a full pipeline will cause a change in the pressure within that pipeline. These changes are given careful attention in the well-designed pipeline; [...]
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Visual context capture and analysis for driver attention monitoring
J. McCall, M. Trivedi

Collection of open conferences in research transport (2005). Vol. 2005, 71

Abstract
Driver distraction is recognized as a major factor in the cause of automobile accidents. Therefore, it is extremely important for an intelligent driver support system to be able to monitor the driver's attentive state. This paper proposes a system to monitor driver attention based on a variety of information sources. The LISA-Q test vehicle is used to synchronously capture video, audio, vehicle information, LASER RADAR information, and GPS information as input to the driver state evaluation. Information about the driver's facial affects, lane keeping, steering movements, and time headway are all extracted from the multimodal data streams and evaluated.
Abstract
Driver distraction is recognized as a major factor in the cause of automobile accidents. Therefore, it is extremely important for an intelligent driver support system to be [...]
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