Abstract
Extensive urban and metropolitan development over the past decades has resulted in the need to better move goods and people over the nation's motorways. However, physical limitations in motorway infrastructure and inefficient use of existing infrastructure have caused considerable economic loss through the late delivery of goods and loss of productive labor, as well as environmental damage, national security concerns, and financial burden resulting from fuel wasted during congestion. Improving utilization of existing physical assets is a crucial and relatively inexpensive means to achieving those ends. The proliferation of inexpensive mobile devices over the past decade has fundamentally changed traffic management, both from the perspective of motorists, as well as planners and logisticians. Motorists now have rapid access to realtime traffic information, and can thus easily re-plan their journeys while already underway. Likewise, organizations that operate these services have access to motorists' whereabouts and itineraries, and are in a position to shape and manage traffic by providing instructions to individual drivers. This research addresses an exploratory agent-based approach towards modeling a road network in which agents 1. have varied routing behaviors and 2. may or may not have access to realtime rerouting capabilities. The objective is to explore what effect modifying driver portfolios will have on the ``price of anarchy" associated with a commuter network. This information can be used by urban planners to determine which driver and information-access portfolios result in the least vehicle delay and best use of motorway resources, thus informing policies and incentives that can alleviate network congestion. Results on a Northern Virginia test case demonstrate that active rerouting has overall modestly positive effects on network latency for small and moderately-sized populations; however, in larger populations, active rerouting can lead to competitive pressures between agents, resulting in overall degradation of performance. It is suggested that future work implement competing managerial agent classes, as well as test over additional geospatial datasets.Abstract
Extensive urban and metropolitan development over the past decades has resulted in the need to better move goods and people over the nation's motorways. However, physical limitations in motorway infrastructure and inefficient use of existing infrastructure have caused considerable [...]Abstract
Introduction"br /" "br /" Risk management in enterprises, organisations and companies has had a long and complicated history. "br /" During the eighties, and at least during the beginning of the nineties, the notion concerning risk management was that if an accident happened in an otherwise perfect system it was due to the human operator in some way being the cause of the error. The cause for the accidents was described in terms of “negligence”, “lack of competence” and such similar statements."br /" "br /" Gradually, during the late nineties, the risk management paradigm shifted. "br /" James Reason, a psychologist, made a tremendous impact with his book Human error, published in 1990."br /" He introduced the term latent failures (or latent conditions). These, he said, are “resident pathogens”, built into the system. They are latent since the system can live with these pathogens for months and even years, and perform adequately, until something happens, which hampers the “immune system of the system”."br /" Reason states that the human operator goes to work everyday with the intention of doing a good job. The human operator has no wish “to screw up things”. When accidents happen, and operators make mistakes, it is therefore not a deliberate action. The causes should be sought in design flaws in the system. "br /" "br /" In this thesis we are dealing with high-risk systems, though not high-risk technologies. We are studying acute somatic health care, air traffic control, pharmacy and cancer treatment. We will explore different ways for an organisation to receive feedback from safety related occurrences, in order to improve safety."br /" "br /" The aim with this thesis will be to explore methods for obtaining safety feedback in the above mentioned domains. "br /" Four different approaches will be attempted:"br /" "br /" • Retrospective learning from accidents (paper I)"br /" • Proactive learning using an external agent (paper II)"br /" • Operator centred learning (paper III)"br /" • User centred proactive learning (paper IV) "br /" "br /" Methods and material"br /" "br /" Methods"br /" "br /" In paper I we used MTO (Man-Technique-Organisation) analysis as described by the nuclear power operators in Sweden, with a certain adaptation for health care. "br /" "br /" Paper II was inspired on the work with paper I. During the numerous interviews with doctors and nurses a quite common reaction was: “Why did we not think of these risks before? It is so obvious!”"br /" Another concern was the limited value of retrospective investigations when it comes to improving safety. "br /" This started us on designing a method for proactive risk analysis. Several methods were already described for this, but they were mainly tuned to technical systems with more or less tight coupling, assuming a high degree of linearity (as for instance the Failure Mode and Effect Analysis, FMEA). We felt these methods did not fit the way in which our studied organisations functioned. The result was the DEB (Disturbance- Effect-Barrier) analysis used in paper II. The identified system weaknesses by using this method was compared to system weaknesses extracted from the analysis (done by headquarter analysts) of 15 loss of separation incidents at the unit."br /" "br /" When working with this it became obvious that one category of incidents, i.e. the loss of separation incidents (AIRPROX) , was only the tip of the iceberg. Each day there were a number of near misses that did not result in loss of separation, and therefore not used for safety feedback. Talking to the controllers also revealed a hidden knowledge on questionable procedures that might constitute risks. Thus the idea was fairly simple: Why not let the controllers do the job of analysing safety occurrences? This led to the design of a method for operator-centred learning, i.e. paper III. The method included a brief to the controllers for 1½ days on system thinking."br /" "br /" The starting point for paper IV was particularly tragic. I investigated a case where an eight-year-old girl with cancer was killed by mistake. She was administered the total dose of cytotoxic agents each day for three days, i.e. a 300% overdose. We used the DEB analysis again, for a proactive risk analysis of the process of treating patients with cytotoxic drugs, but this time using a formalised user group. "br /" "br /" Material"br /" The material for paper I was a consecutive series of eight reports to the National Board of Health and Welfare, from acute somatic health care."br /" "br /" The material for paper II was a DEB analysis performed for the processes at the Malmoe air traffic control unit in Sweden."br /" "br /" In paper III a trial was performed for half a year with extended reporting of learning occurrences. In this way an additional 45 occurrences were reported which otherwise would not have been documented and analysed."br /" "br /" In paper IV the DEB analysis were performed at one ward unit at the department of oncology at the Lund University hospital, taking into consideration interface problems between the ward unit and the hospital pharmacy (which prepared the cytotoxic infusions)."br /" "br /" Results"br /" In paper I we could demonstrate that the notion of latent conditions was fruitful for analysing and learning from medical accidents. We identified a number of system weaknesses in seven out of eight cases, providing a good potential for improving safety."br /" "br /" In paper II we identified a number of risks (latent conditions) in the air traffic control system. We compared the identified system weaknesses with 15 loss of separation cases, investigated by the regulator. We identified all system weaknesses from 14 out of 15 as loss of separation analyses. "br /" In paper III we could demonstrate that the operators indeed were able to analyse “learning occurrences”, and to identify preventive actions, one of these being training on the aircraft flight management system for controllers. Also, they could show that quite a few number of “unexpected flight behaviours” actually were actually partly caused by air traffic control actions."br /" "br /" In paper IV we refined the DEB analysis by using a formalised reference group of staff from the very beginning.. The analysis disclosed a number of system weaknesses, which were presented for the staff. The disclosed risks were accepted as valid, and quite a few of our recommendations were implemented during the next couple of years"br /" "br /" Discussion"br /" We discuss our methods in relation to current research, particularly we discuss MTO analysis in relation to root cause analysis, and DEB analysis in relation to FMEA. We are critical to both. We find that both methods could benefit from using the notion of latent conditions, and even applying the concept and vocabulary from the ISO 9000 quality management standard when describing risks."br /" "br /" We discuss the learning potential of retrospective vs. proactive analysis and are in favour of proactive methods."br /" "br /" We introduce complexity theory and relate this to our results. Our conclusion is that the operator-centred approach (paper III) seems to be the most effective way of influencing a complex system in a desirable manner, concerning self-organising and emergent properties. Hantering av risker i företag och organisationer har haft en lång och komplicerad historia. "br /" På åttiotalet, och i början av nittiotalet, var uppfattningen att om en olycka inträffade i en organisation, som påstods vara nära nog perfekt, måste det bero på ”den mänskliga faktorn”, dvs. att en eller flera medarbetare inte gjorde som de borde ha gjort. Orsakerna till olyckan beskrevs i termer av försumlighet, bristfällig kompetens och slarv."br /" "br /" Synen på riskhantering ändrades så småningom på sent nittiotal. James Reason, en psykolog vid University of Manchester, fick stor genomslagskraft med sin bok ”Human error”. Han introducerade begreppet ”latenta fel” (eller ”latenta förhållanden”). Dessa latenta fel, menade han, var ”sjukdomsalstrare”, inbyggt i produktionssystemen. Ett produktionssystem kan leva med dessa länge, tills något händer som stör produktionssystemets ”immunsystem”. En jämförelse från det medicinska området är att våra kroppar härbärgerar många potentiellt farliga mikroorganismer, men de hålls i schack av andra mikroorganismer och vårt immunsystem som utgörs av olika vita blodkroppar. Om vårt immunsystem slås ut, som t.ex vid cellgiftsbehandling, blir dessa bakterier plötsligt väldigt farliga för vår hälsa. "br /" "br /" På samma sätt kan oförutsedda händelser inträffa i ett produktionssystem. Ett antal latenta fel byter skepnad från att vara latenta till i högsta grad aktiva, och kan orsaka en olycka."br /" "br /" Reason säger att människan i systemet, medarbetaren, går till arbetet varje dag med ambitionen att göra ett bra jobb. Medarbetaren går inte till jobbet med målsättningen att orsaka en olycka. När därför olyckor inträffar för att medarbetare gör fel, är det inte för att medarbetaren avsiktligt har gjort ett fel. Det är snarare så att medarbetaren har fångats i en ”felfälla” pga. brister i utformningen av produktionssystemet."br /" "br /" Denna avhandling rör högrisksystem, men inte högriskteknologi . Vi undersöker akut somatisk sjukvård, flygtrafikledning, apotek och en cancerklinik. Vi vill undersöka olika sätt för en organisation att få återkoppling från inträffade händelser/olyckor så att den kan lära av dessa, och förhoppningsvis förbättra säkerheten. "br /" "br /" Målet för avhandlingen är att undersöka olika sätt att åstadkomma denna återkoppling på, samt att reflektera över om några av dessa sätt är bättre än andra när det gäller att få en organisationen att dra nytta av informationen."br /" "br /" Vi vill pröva fyra olika tillvägagångssätt för att inhämta information om risker:"br /" "br /" • Retrospektivt lärande från inträffade händelser/olyckor (paper I)"br /" • Proaktivt lärande, dvs. få information om risker i systemet utan att vänta på att en olycka skall avslöja riskerna. Här använder vi en expert för att göra analysen (paper II)"br /" • Operatörscentrerat lärande. Här låter vi ”folk på golvet” stå för datainsamling och analys (paper III)"br /" • Användarcentrerat proaktivt lärande. Analysmetoden är den samma som i paper II, men med den skillnaden att vi använder en referensgrupp som består av ”folk på golvet”, dvs. det blir mindre av expertinflytande och mer av medarbetarinflytande under analysens gång (paper IV)."br /" "br /" "br /" "br /" Metoder och material"br /" "br /" Metoder"br /" "br /" I paper I använde vi MTO (Människa-Teknik-Organisation) analys som beskrivits av kärnkraftsoperatörer i Sverige. Dock gjorde vi en viss anpassning från kärnkraft till sjukvård."br /" "br /" Paper II var inspirerat av arbetet med paper I. Vid de talrika intervjuer med läkare och sköterskor som genomfördes i paper I var en återkommande reaktion: ”Varför tänkte vi inte på dessa risker innan olyckan? Det är ju så tydligt.”"br /" En annan reflektion var att retrospektiva riskanalyser kan vara bra för att förhindra en liknande olycka men att sannolikheten för att detta skulle inträffa, med exakt de samma förtecken, är minimal (jfr Tage Danielssons monolog om Harrisburg (Three Mile Island): ”Det kanske var bra det som hände i Harrisburg, fast det var osannolikt, men nu kan det osannolika inte hända i Harrisburg… igen”)."br /" "br /" Detta fick oss att börja designa en metod för proaktiv riskanalys. Åtskilliga metoder för detta hade redan publicerats men dessa var i huvudsak inriktade på tekniska system, och förutsatte en hög grad av linearitet (om A inträffar, så inträffar med stor sannolikhet B och sedan C). Vi tyckte inte att dessa metoder var applicerbara på de organisationer som var i fokus för vår forskning (sjukvård, flygtrafikledning). Dessa fungerade i högsta grad icke-linjärt, eller komplext. Resultatet var DEB (Disturbance-Effect-Barrier) analysen som användes i paper II. Med denna metod hittade vi ett antal systemsvagheter (latenta fel och bristfälliga säkerhetsbarriärer) som vi jämförde med systemsvagheter som framgick av den centrala utredningsavdelnings analys av 15 fall av separationsunderskridande ."br /" "br /" Under arbetet med paper II fick vi klart för oss att händelser med separationsunderskridande (AIRPROX) endast utgjorde en liten del av den information som kunde användas för att öka säkerheten. Regelbundet ägde händelser rum som var ”nära händelser”, dvs. en mer eller mindre okontrollerad situation som upptäcktes i tid så att händelsen inte utvecklades till ett separationsunderskridande. Vi uppfattade således att AIRPROX - händelser var ”toppen av isberget” och funderade på hur vi kunde komma åt en del av resten av isberget. Genom samtal med flygtrafikledarna upplevde vi att de hade en stor ”dold” kunskap om potentiellt riskfyllda rutiner och procedurer. Ur dessa iakttagelser kläcktes följande idé: Varför inte låta flygtrafikledarna själva stå för analysen av säkerhetsrelaterade händelser? Vi utvecklade därför en metod för operatörscentrerat lärande (paper III). I metoden ingick utbildning av flygledarna i ”systemtänk” om 1½ dag, samt formulering av vilka säkerhetsrelaterade händelser (utöver AIRPROX) de skulle rapportera och analysera."br /" "br /" Utgångspunkten för paper IV var tragisk. Författaren till denna avhandling utredde ett fall där en åtta år gammal flicka miste livet. Hon hade cancer, och fick av misstag totaldosen av ett cellgift varje dag i tre dagar, således en överdosering med 300 %. "br /" "br /" Kliniken bad oss göra en proaktiv riskanalys. Vi använde DEB - analysen igen, på processen ”att behandla patienter med cellgifter”. Denna gång använde vi en formaliserad referensgrupp av läkare och sjuksköterskor, utsedda av kliniken."br /" "br /" Material"br /" "br /" Materialet till paper I var en konsekutiv serie av rapporter (så kallade Lex Maria-anmälningar) till Socialstyrelsen i Malmö, från akut somatisk vård."br /" "br /" Underlaget för paper II var en DEB - analys av flygtrafikledningsprocessen vid Malmö Air Traffic Control Centre (ATCC Malmoe)."br /" "br /" Materialet för paper III var en utökad rapportering av säkerhetsrelaterade händelser under en sex månaders försöksperiod. Under perioden rapporterades 45 händelser som annars inte skulle ha dokumenterats och analyserats."br /" "br /" I paper IV gjorde vi en DEB - analys av risker vid behandling av patienter med cellgifter, vid en vårdenhet på onkologiska kliniken, Lunds universitetssjukhus. I analysen ingick även analys av gränssnittsproblem mellan kliniken och sjukhusapoteket (som tillverkar infusionspåsarna med cellgifter)."br /" "br /" Resultat"br /" "br /" I paper I visade vi att det var givande att använda idén om latenta fel/latenta förhållanden för analys och lärande från olyckor i sjukvården. I sju av de åtta analyserade händelserna hittade vi risker i form av inbäddade latenta fel som det var möjligt att åtgärda."br /" "br /" I paper II identifierade vi ett antal risker (latenta fel) i ett flygtrafikledningssystem med DEB - analys . Vi jämförde våra resultat med de latenta fel som framgick av 15 fall av AIRPROX, utredd av tillsynsmyndigheten (Luftfartsverket). DEB - analysen identifierade 14 av de 15 systembrister som framgick av AIRPROX utredningarna."br /" "br /" I paper III visade vi att flygledarna mycket väl kunde analysera ”lärande händelser” och föreslå preventiva åtgärder. En sådan preventiv åtgärd var behov av att utbilda flygledare i hur ett flygplans autopilot ”tänkte”. Ett annat resultat var att ganska många fall där flygplanet gjorde något oväntat, och som traditionellt av flygledarna hade betecknats som SBS (”Skit Bakom Spakarna”) faktiskt visade sig delvis ha orsakats av flygtrafikledningen, och alltså inte bara var flight deck error."br /" "br /" I paper IV förfinade vi DEB - analysen genom att från första början luta oss mot en formaliserad referensgrupp av läkare och sjuksköterskor från kliniken. Analysen visade på ett antal systemsvagheter/risker. Detta presenterades för medarbetarna vid ett möte och accepterades som förståndigt (en korridorskommentar efter mötet: ”Det var en bra sågning”!)."br /" En stor del av våra förbättringsförslag implementerades sedan."br /" "br /" "br /" Diskussion"br /" "br /" Vi diskuterar våra metoder utifrån det aktuella forskningsläget, i synnerhet diskuterar vi MTO - analys i relation till root cause analysis, och DEB - analys i relation till FMEA (Failure Mode and Effect Analysis). Vi är tämligen kritiska till båda. Vi menar att båda dessa metoder kunde förbättras och ge bättre resultat om man dels använde ”latenta förhållande konceptet”, dels tillämpade vokabulär och koncept från ISO 9000 - standarden för kvalitetsledningssystem."br /" "br /" Vi diskuterar potentialen för lärande för retrospektiva och proaktiva metoder och rekommenderar proaktiva metoder, såsom DEB - analysen."br /" "br /" Vi introducerar komplexitetsteori och relaterar denna till våra resultat. Vår konklusion är att den operatörscentrerade metoden (paper III) tycks vara den mest effektiva metoden för att påverka ett komplext system vad gäller systemets förmåga till självorganisering och önskvärda framväxande egenskaper (emergent properties).Abstract
Introduction"br /" "br /" Risk management in enterprises, organisations and companies has had a long and complicated history. "br /" During the eighties, and at least during the beginning of the nineties, the notion concerning risk management was that if an accident happened in an [...]Abstract
The concept of resilience can be realized in natural and engineering systems, representing the ability of system to adapt and recover from various disturbances. Although resilience is a critical property needed for understanding and managing the risks and collapses of transportation system, an accepted and useful definition of resilience for urban traffic as well as its statistical property under perturbations is still missing. Here we define city traffic resilience based on the spatio-temporal clusters of congestion in real traffic, and find that the resilience follows a scale free distribution in two-dimensional city road networks and one-dimensional highways, with different exponents, but similar exponents in different days and different cities. The traffic resilience is also revealed to have a novel scaling relation between the cluster size of the spatio-temporal jam and its recovery duration, independent of microscopic details. Our findings of universal traffic resilience can provide indication towards better understanding and designing these complex engineering systems under internal and external disturbances. Comment: 6 pages, 4 figure Document type: ArticleAbstract
The concept of resilience can be realized in natural and engineering systems, representing the ability of system to adapt and recover from various disturbances. Although resilience is a critical property needed for understanding and managing the risks and collapses of transportation [...]Abstract
transport is a key infrastructure of modern societies. In this paper we review some recent approaches to air transport, which make extensive use of theory of complex networks. We discuss possible networks that can be defined for the air transport and we focus our attention to networks of airports connected by flights. We review several papers investigating the topology of these networks and their dynamics for time scales ranging from years to intraday intervals, and consider also the resilience properties of air networks to extreme events. Finally we discuss the results of some recent papers investigating the dynamics on air transport network, with emphasis on passengers traveling in the network and epidemic spreading mediated by air transport. Comment: 28 pages, 6 figureAbstract
transport is a key infrastructure of modern societies. In this paper we review some recent approaches to air transport, which make extensive use of theory of complex networks. We discuss possible networks that can be defined for the air transport and we focus our attention to networks [...]Abstract
Modern society is facing great challenges due to pollution and increased carbon dioxide (CO2) emissions. As part of solving these challenges, the use of renewable energy sources and electric vehicles (EVs) is rapidly increasing. However, increased dynamics have triggered problems in balancing energy supply and consumption demand in the power systems. The resulting uncertainty and unpredictability of energy production, consumption, and management of peak loads has caused an increase in costs for energy market actors. Therefore, the means for studying the balancing of local smart grids with EVs is a starting point for this paper. The main contribution is a simulation-based approach which was developed to enable the study of the balancing of local distribution grids with EV batteries in a cost-efficient manner. The simulation-based approach is applied to enable the execution of a distributed system with the simulation of a local distribution grid, including a number of charging stations and EVs. A simulation system has been constructed to support the simulation-based approach. The evaluation has been carried out by executing the scenario related to balancing local distribution grids with EV batteries in a step-by-step manner. The evaluation results indicate that the simulation-based approach is able to facilitate the evaluation of smart grid– and EV-related communication protocols, control algorithms for charging, and functionalities of local distribution grids as part of a complex, critical cyber-physical system. In addition, the simulation system is able to incorporate advanced methods for monitoring, controlling, tracking, and modeling behavior. The simulation model of the local distribution grid can be executed with the smart control of charging and discharging powers of the EVs according to the load situation in the local distribution grid. The resulting simulation system can be applied to the study of balancing local smart grids with EV batteries. Based on the evaluation results, it is estimated that the simulation-based approach can provide an essential, safe, and cost-efficient method for the evaluation of complex, critical cyber-physical systems, such as smart grids. Document type: ArticleAbstract
Modern society is facing great challenges due to pollution and increased carbon dioxide (CO2) emissions. As part of solving these challenges, the use of renewable energy sources and electric vehicles (EVs) is rapidly increasing. However, increased dynamics have triggered problems [...]Abstract
In this contribution, we study the properties of new promising graphenebased materials with shape memory effects. While traditional shape memory alloys have been extensively studied, it is a challenge to preserve shape memory properties at the nanoscale. As a result, new materials have been explored, among which graphene oxide (GO) crystals with ordered epoxy groups where a recoverable strain of 14.5% has already been reported. We use such nanoscale GO structures as a benchmark example for our studies here. MBTR and SOAP representations are employed in a general-purpose ML model to analyze the effect of long-range interactions in GO. Finally, a physics-based ML model allows us to build interatomic potentials for 2D and 1D systems. The model predicts quantum mechanical effects due to the electronic confinement in narrow nanoribbons and shows the evolution of the local minimal energies associated with two-phase states.
Abstract
In this contribution, we study the properties of new promising graphenebased materials with shape memory effects. While traditional shape memory alloys have been extensively studied, it is a challenge to preserve shape memory properties at the nanoscale. As a result, new materials [...]
Abstract
Anàlisi de les exportacions de béns catalanes i la seva complexitat econòmica: Abstract pel "IV Congrés d’Economia i Empresa: Eix 2. Determinants del context macroeconòmic"
Helena Linares-Arlanzón1 i Maximilian Schäfer-i-Paradís1
1Generalitat de Catalunya, Departament d'Economia i Hisenda, Direcció General d'Anàlisi i Prospectiva Econòmica, Carrer del Foc, 57 08038 Barcelona
Catalunya gaudeix d’una base industrial i d’una orientació exportadora destacable, que la situen com la primera comunitat autònoma en volum d’exportacions de béns, amb el 26,3% del total estatal el 2023. Aquest treball analitza l'evolució de les exportacions de béns de Catalunya i les seves províncies (i.e., Barcelona, Girona, Lleida i Tarragona) des de dues perspectives. D'una banda, s'explora la seva evolució històrica, destacant els components clau i els trets distintius de l'estructura exportadora catalana. D'altra banda, es du a terme una anàlisi de la complexitat econòmica i l'avantatge competitiu de les exportacions, oferint una visió integral del panorama exportador del territori.
Per tal d'analitzar la competitivitat sectorial, s'ha calculat l'índex d'avantatge comparatiu revelat (RCA, per les seves sigles en anglès) que mesura el grau d'especialització en les exportacions d'un producte (Balassa, 1963) Com a mesura de qualitat de les exportacions, hem utilitzat l'índex de complexitat econòmica (ICE), definit per Hidalgo i Hausmann (2009), que calcula el coneixement acumulat d'un territori per tal d'exportar productes que són escassos en el mercat internacional. Un nivell d'ICE alt es relaciona així amb un desenvolupament econòmic pronunciat i, tanmateix, amb una capacitat exportadora futura més elevada. Els indicadors de complexitat de l'economia catalana s'han basat en les dades proporcionades per COTEC.
Els resultats indiquen una disminució de la complexitat econòmica en les exportacions de béns de Catalunya entre el 2017 i el 2022. Tot i això, en els darrers 2 anys s’observa una millora de l’ICE de Catalunya que ha permès tornar a situar a la regió en la tercera posició del rànquing autonòmic, gràcies sobretot a l’evolució favorable dels productes químics i del material de transport. En termes més desagregats, Barcelona és la quarta província de l’Estat amb major nivell de complexitat el 2022, mentre que la resta de províncies catalanes mostren una sofisticació negativa (Girona, Tarragona i Lleida, se situen a la posició 12, 25 i 34, respectivament).
Pel que fa a l’avantatge competitiu, dels productes analitzats per Catalunya el 2022, gairebé un 52% mostren un valor competitiu de l'RCA (i.e., RCA superior a 1), on destaquen els productes animals i els químics. No obstant això, d’aquests productes especialitzats, menys del 10% tenen una complexitat del producte (PCI) positiva.
Finalment, s’aplica un model economètric (vegi's l'Equació (1)) per inferir l’impacte del nivell de l'ICE sobre el valor total de les exportacions catalanes del 2022. S’observa un efecte positiu i estadísticament significatiu. De fet, la magnitud de l'efecte és superior al d'altres variables clau (e.g., l’RCA, el nivell de les infraestructures de transport i la mida del teixit empresarial provincial).
ln(exp_iz/PIB_z) = alpha + beta ln(ICE_z) + gamma ln(RCA_iz) + theta ln(X_z) + xi_iz (1)
Fig. 1. Evolució de la complexitat de les exportacions catalanes (2017-2022). Nota: La mida dels punts augmenta segons el valor RCA de cada producte.
Taula 1. Regressions OLS.
Bibliografia
Balassa, Bela. An empirical demonstration of classical comparative cost theory, The Review of Economics and Statistics (1963): 231-238.
Hidalgo, Cesar A., and Ricardo Hausmann, The building blocks of economic complexity, Proceedings of the national academy of sciences (2009): 10570-10575.
Abstract
Anàlisi de les exportacions de béns catalanes i la seva complexitat econòmica: Abstract pel "IV Congrés d’Economia i Empresa: Eix 2. Determinants del context macroeconòmic"
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Abstract
fter the emergence of the H1N1 influenza in 2009, some countries responded with travel-related controls during the early stage of the outbreak in an attempt to contain or slow down its international spread. These controls along with self-imposed travel limitations contributed to a decline of about 40% in international air traffic to/from Mexico following the international alert. However, no containment was achieved by such restrictions and the virus was able to reach pandemic proportions in a short time. When gauging the value and efficacy of mobility and travel restrictions it is crucial to rely on epidemic models that integrate the wide range of features characterizing human mobility and the many options available to public health organizations for responding to a pandemic. Here we present a comprehensive computational and theoretical study of the role of travel restrictions in halting and delaying pandemics by using a model that explicitly integrates air travel and short-range mobility data with high-resolution demographic data across the world and that is validated by the accumulation of data from the 2009 H1N1 pandemic. We explore alternative scenarios for the 2009 H1N1 pandemic by assessing the potential impact of mobility restrictions that vary with respect to their magnitude and their position in the pandemic timeline. We provide a quantitative discussion of the delay obtained by different mobility restrictions and the likelihood of containing outbreaks of infectious diseases at their source, confirming the limited value and feasibility of international travel restrictions. These results are rationalized in the theoretical framework characterizing the invasion dynamics of the epidemics at the metapopulation level. This work has been partially funded by the National Institutes of Health R21-DA024259 award, the Lilly Endowment grant 2008 1639-000 and the DTRA-1-0910039 award to AV; the EC-ICT contract no. 231807 (EPIWORK) to AV and VC; the EC-FET contract no. 233847 (DYNANETS) to AV, VC, and JJR; the ERC Ideas contract n.ERC-2007-Stg204863 (EPIFOR) to VC, PB, CP, and MT. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Peer reviewed Document type: ArticleAbstract
fter the emergence of the H1N1 influenza in 2009, some countries responded with travel-related controls during the early stage of the outbreak in an attempt to contain or slow down its international spread. These controls along with self-imposed travel limitations contributed to a [...]