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  • 1.
    Aaboen, Lise
    NTNU, Trondheim.
    BATON-CHANGING ON EGGSHELLS – TRANSFERRING SUPPLIER RELATIONSHIPS WHEN MOVING PRODUCTION2014Conference paper (Refereed)
    Abstract [en]

    Production transfers are a result of outsourcing and offshoring decisions. Though, because of

    the strategic focus of the outsourcing literature have not the operational issues of how

    relationship development between sender, receiver and raw material been fully depicted. The

    purpose of the present paper is to explore relationship development connected to transfer of

    raw material supplies responsibility during transfer of production. To fulfil the purpose, four

    different production transfers were studied: three from Sweden to China, Romania and

    Hungary respectively and one transfer from Holland to Sweden. We can see that the

    dependence and power shifts gradually between the sender and the receiver and the

    relationship between them sets the arena for what relationship is developed between the

    receiver and the raw material suppliers. Furthermore, short social distances can over bridge

    cultural and technological distances to some extent, because it motivates to take the

    relationship into a more developed state.

  • 2.
    Aaboen, Lise
    et al.
    Department of Industrial Economics and Technology Management, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
    Fredriksson, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    The relationship development aspect of production transfer2016In: Journal of Purchasing and Supply Management, ISSN 1478-4092, E-ISSN 1873-6505, Vol. 22, no 1, 53-65 p.Article in journal (Refereed)
    Abstract [en]

    Production transfers are a result of outsourcing and offshoring decisions. Because of the strategic focus of the outsourcing literature, the operational issues of relationship development between sender and receiver and its impact on the transfer progress have not been fully depicted. The purpose of the present paper is to explore relationship development during production transfer. To fulfil this purpose, we studied three different production transfers and derived four propositions for further testing. Our main conclusions included that dependence and power gradually shift between the sender and the receiver and that the relationship between them sets the arena for what types of relationships can be developed between the receiver and the suppliers. Furthermore, short social distances can bridge cultural and technological distances to some extent, because it motivates the actors to bring their relationship into a more developed state. Finally, we noticed that the headquarters’ involvement can work both as an inhibitor as well as a converter.

  • 3.
    Aban, Kevin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Göst, Jens
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Analysis of transports with pharmaceuticals on Arlanda airport2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Rapporten syftar till att kartlägga och analysera dagens transportflöde av läkemedel på fraktområdet Cargo City på Arlanda. Cargo Center och APH Logistics är två fraktagenter som har sin verksamhet på Cargo City. Observera att Cargo City och Cargo Center inte har samma innebörd. Cargo Center och APH Logistics erbjuder genom nära samarbete transport och hantering av temperaturkänsligt gods, som till exempel läkemedel. Läkemedel är värdefullt gods som kräver särskild skötsel vid transport, hantering och förvaring. Det ställer stränga krav på samtliga aktörer i försörjningskedjan. Genom studiebesök och intervjuer har författarna kartlagt det befintliga flödet av läkemedel. SACT, ett åkeri och dotterbolag till Cargo Center, utför transporten av godset till Cargo City med nerkylda lastbilar. APH Logistics omlastningsterminal på Cargo City är temperaturkontrollerad, vilket innebär att läkemedelsgodset förvaras och lastats i flygcontainrar där. Det färdiglastade godset forslas sedan vidare till Cargo Centers terminal. Där sker vikt- och volymkontroll av godset, det registreras i olika datasystem och slutligen märks det med etiketter, så som flygfraktsedeln. Mycket av godset som hanteras på Arlanda körs med lastbil till andra flygplatser och destinationer runt om i Europa istället för att flygfraktas direkt från flygplatsen. Dessutom hanteras och förvaras inte allt läkemedelsgods under temperaturkontrollerade former. En totalkostnadsanalys har gjorts för att jämföra olika transportflödesscenarion. Dessutom har författarna identifierat den kundservice Cargo Center och APH Logistics bör erbjuda kunden. Den bygger på kvalitativa resonemang. Resultatet av rapporten är författarnas rekommendation till företagen av hur de bör gå tillväga i framtiden. Den ger både kortsiktiga och långsiktiga tips.

  • 4. Abate, M.
    et al.
    De Jong, Gerard
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    The optimal shipment size and truck size choice - The allocation of trucks across hauls2014In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 59, 262-277 p.Article in journal (Refereed)
    Abstract [en]

    There has been a growing interest in understanding how firms allocate their trucks across hauls, and how this allocation changes under various economic environments. This study investigates how variations in route/haul, carrier and vehicle characteristics affect the optimal vehicle size choice and the associated choice of shipment size. We show that the two choices are derived from the same optimization problem. There can be a continuum of shipment sizes, but decision-makers in freight transport have to choose from a limited number of vehicle alternatives. Therefore, we use a discrete-continuous econometric model where shipment size is modeled as a continuous variable, and vehicle size/type choice as a discrete variable. The results indicate that when faced with higher demand, and during longer trips firms are more likely to use heavier vehicles and ship in larger quantities which suggest that firms are realizing economies of scale and economies of distance. The study also discusses the effect of vehicle operating cost on the vehicle selection process and its policy implications.

  • 5.
    Abate, Megersa
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    Determinants of Capacity Utilisation in Road Freight Transportation2014In: Journal of Transport Economics and Policy, ISSN 0022-5258, E-ISSN 1754-5951, Vol. 48, 137-152 p.Article in journal (Refereed)
    Abstract [en]

    Recent performance indicators in the European road freight transport sector show there is an excess capacity. To shed light on this, this paper studies two aspects of capacity utilisation in trucking: the extent of empty running and the load factor. Using a joint econometric modelling framework, the paper shows that they can be explained as a function of haul, carrier, and truck characteristics. For estimation, a unique dataset from the Danish heavy vehicle trip diary was used. The results indicate distance and being a for-hire carrier have a positive effect on capacity utilisation, whereas the effect of truck size is non-linear.

  • 6.
    Abate, Megersa
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    De Jong, Gerard
    University of Leeds.
    The optimal shipment size and truck size choice: The allocation of trucks across hauls2014In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 59, 262-277 p.Article in journal (Refereed)
    Abstract [en]

    There has been a growing interest in understanding how firms allocate their trucks across hauls, and how this allocation changes under various economic environments. This study investigates how variations in route/haul, carrier and vehicle characteristics affect the optimal vehicle size choice and the associated choice of shipment size. We show that the two choices are derived from the same optimization problem. There can be a continuum of shipment sizes, but decision-makers in freight transport have to choose from a limited number of vehicle alternatives. Therefore, we use a discrete-continuous econometric model where shipment size is modeled as a continuous variable, and vehicle size/type choice as a discrete variable. The results indicate that when faced with higher demand, and during longer trips firms are more likely to use heavier vehicles and ship in larger quantities which suggest that firms are realizing economies of scale and economies of distance. The study also discusses the effect of vehicle operating cost on the vehicle selection process and its policy implications.

  • 7.
    Abate, Megersa
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    Vierth, Inge
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    de Jong, Gerard
    University of Leeds.
    Joint econometric models of freight transport chain and shipment size choice2014Report (Other academic)
    Abstract [en]

    In freight transportation, decisions regarding the choice of transport mode (or chains of modes) and shipment size are closely linked. Building on this basic insight, in this paper we estimate and review various joint econometric models using the Swedish National Commodity Flow surveys. Robust parameter estimates from this exercise will be used to update the current deterministic Swedish national freight model system (the SAMGODS model) to a stochastic one.

  • 8.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of nanostructured particles in railway tunnels2013Report (Other academic)
  • 9.
    Abid, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.). Högskolan i Gävle, Sweden.
    Bengtsson, Lars
    Dabhilkar, Mandar
    Factors affecting shifts in global supply chain networks: A configurational approach2013In: Proceedings of the 20th International Annual EurOMA conference, Dublin, Ireland, 9-12 June 2013, 2013, 2013Conference paper (Refereed)
    Abstract [en]

    In certain situations, global companies strive to take advantage of short-term changes in economic and exchange rates on the never-ending journey of competitiveness. This paper seeks to extend Ferdows’s (2008) production network models by adding the factors affecting shifts between rooted and footloose network configurations. Two companies were selected in order to illustrate the models and reveal other possible factors. The identified factors are differentiated in terms of configuration and coordination and merged in a matrix. The trends and implications on global supply chains are also discussed.

  • 10.
    Abubakr, Raowa
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Patel, Pooja
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Packaging systems decision makin; to assure cost efficient transports2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 11.
    Adedokun, Adeyemi
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Application of Road Infrastructure Safety Assessment Methods at Intersections2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Traffic safety at intersections is a particularly difficult phenomenon to study, given the fact that accidents occur randomly in time and space thereby making short-term measurement, assessment and comparison difficult. The EU directive 2008/96/EC introduced road infrastructure safety management, which offers a five layer structure for developing safer road infrastructure has been used to develop tools for accident prediction and black spot management analysis which has been applied in this work to assess the safety level of intersections in Norrköping city in Sweden. Accident data history from STRADA (Swedish Traffic Accident Data Acquisition) and the network demand model for Norrköping city were used to model black spots and predict the expected number of accidents at intersections using PTV Visum Safety tool, after STRADA accident classification was restructured and the Swedish accident prediction model (APM) was configured and tested to work within the tool using the model from the Swedish road administration (SRA). The performance of the default (Swiss) and the Swedish APM was compared and identified locations with the high accident records, predicted accident counts and traffic volumes were audited using qualitative assessment checklist from Street-Audit tool. The results from these methods were analysed, validated and compared. This work provides recommendations on the used quantitative and qualitative methods to prevent accident occurrence at the identified locations.

  • 12.
    Adelsköld, Astrid
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Review of general demand responsive transport in Sörmland county2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sörmlands län består till stor del av landsbygd där en kostnadseffektiv kollektivtrafik är svår att uppnå eftersom resandeunderlaget och därmed även efterfrågan normalt är låg. I dessa områden finns dock potential att uppnå en hållbar kollektivtrafik med hjälp av anropsstyrda trafikformer. I detta projekt utreddes dels en övergång av turer i landsbygdslinjetrafiken till allmän anropsstyrd trafik och dels en samordning av den allmänna och särskilda anropsstyrda kollektivtrafiken. En generell metod för val mellan fast linjetrafik och anropsstyrd linjelagd trafik utvecklades, vilken bestod av enkla tumregler för utvärdering av turer med regelbundet låg efterfrågan i landsbygdslinjetrafiken. Samordningen bestod av att utreda effekterna av att kompletteringsresor planerades och utfördes med samma fordon som den särskilda anropsstyrda kollektivtrafiken. Då kompletteringstrafiken får en högre kostnadseffektivitet genom samordning med den särskilda kollektivtrafiken kan denna användas som en flexibel ersättning där turutbudet i landsbygdslinjetrafiken behöver minska. En kostnadseffektivisering av landsbygdslinjetrafiken där turutbudet anpassas bättre till efterfrågan tillåter därmed en satsning av resurser till kompletteringstrafiken. Detta för att i enlighet med kollektivtrafikmyndighetens mål skapa en attraktiv kollektivtrafik för hållbar tillväxt och utveckling i Sörmlands län.

  • 13.
    Adolfsson, Lovisa
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Nilsson, Rebecca
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Collection structure design of deposited PET bottles and aluminium cans in northern Sweden2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Returpack är ansvariga för Sveriges retursystem av tomma PET-flaskor och aluminiumburkar där insamling och hantering av förpackningar är en stor del av verksamheten. Transport av tomma förpackningar från butik till Returpacks fabrik i Norrköping sker huvudsakligen i form av lösvikt (bulklast) av Returpack. Övriga transporter av förpackningar sker i kartong eller säck där dryckesleverantörer sköter insamlingen. Syftet med denna studie är att skapa och undersöka olika typer av inhämtningsstrukturer för tomma förpackningar, där Returpack strävar efter att på ett kostnadseffektivt och miljömässigt sätt sköta inhämtningen samt öka kontrollen över flödet. I studien kommer fem områden i norra Sverige att undersökas, vilka skiljer sig från övriga områden i Sverige då dessa kännetecknas av långa avstånd mellan butiker samt låga volymer av förpackningar. I studien utförs ruttplanering av lösviktsinsamling samt totalkostnadberäkningar för varje område, där ett antal scenarier skapats med olika typer av inhämtningsstrukturer. I scenarierna varieras antalet butiker, mellanlager, ruttider samt insamlingsbilar. Utöver detta undersöks även fyra olika hubblösningar där förpackningarna gör en övergång från kartong- och säckflödet till lösviktsflödet. Resultaten av ruttplanerningarna visar att två av områdena har en hög belastning där antalet insamlingsbilar behöver ökas. Totalkostnadsberäkningarna tyder på att det går att sänka totalkostnaden i två av områdena genom att öka lösviktsinsamlingen. I de övriga tre områdena ger den nuvarande strukturen den lägsta totalkostnaden. Resultaten visar också att antalet fordonskilometer kan minska genom att addera ytterligare ett mellanlager i två av områdena. I studien visas det också att hubbar kan sänka kostnader för Returpack och minska antalet inkommande kartonger och säckar till fabriken. Att införa hubbar minskar också antalet fordonskilometer med mer än 50 %.

  • 14.
    Aghighi, Meysam
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Bäckström, Christer
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Cost-optimal and Net-benefit Planning--A Parameterised Complexity View2015In: 24th International Joint Conference on Artificial Intelligence (IJCAI-15), 2015Conference paper (Refereed)
    Abstract [en]

    Cost-optimal planning (COP) uses action costs and asks for a minimum-cost plan. It is sometimes assumed that there is no harm in using actions with zero cost or rational cost. Classical complexity analysis does not contradict this assumption; planning is PSPACE-complete regardless of whether action costs are positive or non-negative, integer or rational. We thus apply parameterised complexity analysis to shed more light on this issue. Our main results are the following. COP is W[2]-complete for positive integer costs, i.e. it is no harder than finding a minimum-length plan, but it is para-NPhard if the costs are non-negative integers or positive rationals. This is a very strong indication that the latter cases are substantially harder. Net-benefit planning (NBP) additionally assigns goal utilities and asks for a plan with maximum difference between its utility and its cost. NBP is para-NP-hard even when action costs and utilities are positive integers, suggesting that it is harder than COP. In addition, we also analyse a large number of subclasses, using both the PUBS restrictions and restricting the number of preconditions and effects.

  • 15.
    Ahlberg, Joakim
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Intermodala transporter: definition, aktörer och omfattning2016Report (Other academic)
    Abstract [en]

    Intermodal and combined transport is often used synonymously today. The concept of combined transport has been around much longer and referred to as transportation where railway and a truck are being combined. Nowadays a combined transport often means that the goods either go by rail, inland waterways or sea and by road, or between two transport modes where trucks are not included. Intermodal and combined transport is often used synonymously today. The concept of combined transport has been around much longer and referred to as transportation where railway and a truck are being combined.

    Nowadays a combined transport often means that the goods either go by rail, inland waterways or sea and by road, or between two transport modes where trucks are not included. The EU’s so-called combi directive defines both in the same way and one of the EU Commission’s proposal to amend this directive is that EU should be considered to replace the concept of combined transport with intermodal transport. An intermodal transport precedes by a transportation decision, and this decision is often linked to a specific train path (tågläge in Swedish). If there is shortage of capacity on the track, the goods may have difficulties to be transported by train. This could potentially mean that some (rail) business / transports will not take place and the goods go by road instead.

  • 16.
    Ahlberg, John
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cruz Wolter Håkansson, Christoffer
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Identification, mapping and control of non-structure-bound materials2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    I Saab Aerostructures tillverkning av flygplansdelar, används icke strukturbundet material, det vill säga material som inte har en angiven kvantifierad förbrukning per tillverkad enhet eller material vars angivna kvantifierade förbrukning per tillverkad enhet inte stämmer överens med verklig förbrukning. Personal på inköpsavdelningen vet i vissa fall inte var ett specifikt icke strukturbundet material förbrukas, alltså vilka tillverkningsavdelningar eller flygplansdelar som förbrukar materialet. Likaså saknas övergripande och gemensamma rutiner för hur material som klassas som icke strukturbundet material planeras och lagerstyrs. För att identifiera problemområden i materialförsörjningen genomfördes en flödeskartläggning för att identifiera vilka olika typer av icke strukturbundet material som används i Saab Aerostructures produktion samt hur dessa lagerstyrs mellan lager och buffertlager i produktion. Under flödeskartläggningen definierades sex olika materialgrupper tillhörande icke strukturbundet material. För att lagerstyra de identifierade materialgrupperna av icke strukturbundet material används idag åtta stycken lagerstyrningsmetoder. Saab Aerostructures har anlitat tredjepartslogistiker för att sköta merparten av dagens lagerstyrning. Lagerstyrningsmetoderna skiljer sig åt beroende på tredjepartslogistiker och materialgrupp av icke strukturbundet material. Resultatet från genomförd kartläggning och analys påvisar att det finns förbättringspotential i flera utav dessa lagerstyrningsmetoder, samt att det är möjligt att reducera antalet lagerstyrningsmetoder genom att använda samma lagerstyrningsmetod för snarlika materialgrupper av icke strukturbundet material. Genomförd analys påvisar även behovet av ett förbättrat informationsflöde mellan beredning, inköp och produktion, när det gäller hanteringen av icke strukturbundet material. Konkreta åtgärder i form av rekommendationer, för att förbättra lagerstyrningen av icke strukturbundet material, presenteras i slutet av denna rapport.  

  • 17.
    Ahlepil, Erik
    et al.
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Björck, Joel
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Evaluating Distribution Structures for Overseas Export of Frozen Food.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The meat producers of the western world needs to develop their export organizations and to streamline their physical distribution in order to take new market shares on the fast growing overseas markets. HKScan is one of those meat producing companies, the group has businesses in Finland, Sweden, Denmark and the Baltic countries. A part of their sales goes frozen on overseas export by container sea freight. Lately the logistics management of HKScan has been interested in investigating the effects of centralizing the physical distribution for the overseas export from Sweden and Denmark. This leads to the purpose of this study, which is:

     “For HKScan, develop and apply a model that evaluates distribution structures for overseas export of frozen food regarding total cost, delivery service, environmental impact and regulations.”

    The case study included comparison between the current distribution structure for HKScan and three pre-determined scenarios. The current setup consists of multiple warehouses in both countries. In the first scenario the distribution structure is centralized to include one warehouse per country. In the second scenario, the total export flow of products from both Sweden and Denmark is redirected and centralized to one warehouse in Denmark. In the third scenario, the total export flow of products from both Sweden and Denmark is instead redirected and centralized to one warehouse in Sweden.

    To evaluate and compare the different distribution structures a general model was first created by combining different theoretical models and adapting them to the context of overseas distribution for frozen food. The study then included the three phases of developing the model to fit the case company, applying the model on the case company and then to finally evaluating the model.

    The resulting model, which was the outcome of the development process, can be seen below. The model illustrates the different included elements.

    By then applying the model onto the case company, HKScan, it was found that a centralization to a joint warehouse in Denmark would make total cost savings of several percents. In addition, this scenario would increase the total service level. However, the environmental impact would be increased due to long cross-border road transport distances and longer land and sea transports from the warehouse. In addition, it was not possible to fully investigate whether such a distribution would be possible from a regulatory point of view.  A centralization in each country would have minor regulatory issues, it would lead to the smallest environmental impact and have a slight increase in service levels as well as a reduction for the total cost of one percent.

    The evaluation of the model showed that it produces reasonable results with the regulatory elements being the hardest to evaluate for the different scenarios. Regarding the detail level, the veterinary element could be accounted for by the warehousing element and the sea freight element split into transport from warehouse to domestic port and sea freight from domestic port to the destination port. The box-model, containing twelve elements, can be seen as generalizable for evaluating distribution structures in similar contexts, Overseas export of frozen food. However, the calculation performed within the model do probably only apply to the specific scenarios in the study.

  • 18. Ahlström, Christer
    et al.
    Fors, Carina
    Anund, Anna
    Hallvig, David
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Video-based observer rated sleepiness versus self-reported subjective sleepiness in real road driving2015In: European Transport Research Review, ISSN 1867-0717, E-ISSN 1866-8887, Vol. 7, no 4, 38Article in journal (Refereed)
    Abstract [en]

    Purpose: Observer-rated sleepiness (ORS) based on video recordings of the driver's face is often used when analysing naturalistic driving data. The aim of this study is to investigate if ORS ratings agree with subjective self-reported sleepiness (SRS). Methods: Forty raters assessed 54 video-clips showing drivers with varying levels of sleepiness. The video-clips were recorded during a field experiment focusing on driver sleepiness using the same cameras that are typically used in large-scale field studies. The weak results prompted a second test. Ten human factors researchers made pairwise comparisons of videos showing the same four participants in an alert versus a very sleepy condition. The task was simply to select the video-clip where the driver was sleepy. Results: The overall average percentage of video segments where ORS and SRS matched was 41 % in Test 1. ORS 0 (alert) and ORS 2 (very sleepy) were easier to score than ORS 1 and it was slightly harder to rate night-time drives. Inter-rater agreement was low, with average Pearson's r correlations of 0.19 and Krippendorff's alpha of 0.15. In Test 2, the average Pearson's r correlations was 0.35 and Krippendorff's alpha was 0.62. The correspondence between ORS and SRS showed an agreement of 35 %. Conclusions: The results indicate that ORS ratings based on real road video recordings correspond poorly with SRS and have low inter-rater agreement. Further research is necessary in order to further evaluate the usefulness of ORS as a measure of sleepiness.

  • 19.
    Ahlström, Christer
    et al.
    Swedish National Rd and Transport Research Institute VTI, S-58195 Linkoping, Sweden.
    Kircher, Katja
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences. Swedish National Rd and Transport Research Institute VTI, S-58195 Linkoping, Sweden.
    A Generalized Method to Extract Visual Time-Sharing Sequences From Naturalistic Driving Data2017In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 18, no 11, 2929-2938 p.Article in journal (Refereed)
    Abstract [en]

    Indicators based on visual time-sharing have been used to investigate drivers visual behaviour during additional task execution. However, visual time-sharing analyses have been restricted to additional tasks with well-defined temporal start and end points and a dedicated visual target area. We introduce a method to automatically extract visual time-sharing sequences directly from eye tracking data. This facilitates investigations of systems, providing continuous information without well-defined start and end points. Furthermore, it becomes possible to investigate time-sharing behavior with other types of glance targets such as the mirrors. Time-sharing sequences are here extracted based on between-glance durations. If glances to a particular target are separated by less than a time-based threshold value, we assume that they belong to the same information intake event. Our results indicate that a 4-s threshold is appropriate. Examples derived from 12 drivers (about 100 hours of eye tracking data), collected in an on-road investigation of an in-vehicle information system, are provided to illustrate sequence-based analyses. This includes the possibility to investigate human-machine interface designs based on the number of glances in the extracted sequences, and to increase the legibility of transition matrices by deriving them from time-sharing sequences instead of single glances. More object-oriented glance behavior analyses, based on additional sensor and information fusion, are identified as the next future step. This would enable automated extraction of time-sharing sequences not only for targets fixed in the vehicles coordinate system, but also for environmental and traffic targets that move independently of the drivers vehicle.

  • 20.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Kircher, Katja
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System. Linköpings Universitet.
    A Generalized Method to Extract Visual Time-Sharing Sequences From Naturalistic Driving Data2017In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 18, no 11, 2929-2938 p.Article in journal (Refereed)
    Abstract [en]

    Indicators based on visual time-sharing have been used to investigate drivers' visual behaviour during additional task execution. However, visual time-sharing analyses have been restricted to additional tasks with well-defined temporal start and end points and a dedicated visual target area. We introduce a method to automatically extract visual time-sharing sequences directly from eye tracking data. This facilitates investigations of systems, providing continuous information without well-defined start and end points. Furthermore, it becomes possible to investigate time-sharing behavior with other types of glance targets such as the mirrors. Time-sharing sequences are here extracted based on between-glance durations. If glances to a particular target are separated by less than a time-based threshold value, we assume that they belong to the same information intake event. Our results indicate that a 4-s threshold is appropriate. Examples derived from 12 drivers (about 100 hours of eye tracking data), collected in an on-road investigation of an in-vehicle information system, are provided to illustrate sequence-based analyses. This includes the possibility to investigate human-machine interface designs based on the number of glances in the extracted sequences, and to increase the legibility of transition matrices by deriving them from time-sharing sequences instead of single glances. More object-oriented glance behavior analyses, based on additional sensor and information fusion, are identified as the next future step. This would enable automated extraction of time-sharing sequences not only for targets fixed in the vehicle's coordinate system, but also for environmental and traffic targets that move independently of the driver's vehicle.

  • 21.
    Ahlström, Christer
    et al.
    Swedish National Rd and Transport Research Institute VTI, S-58195 Linkoping, Sweden.
    Kircher, Katja
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences. Swedish National Rd and Transport Research Institute VTI, S-58195 Linkoping, Sweden.
    Changes in glance behaviour when using a visual eco-driving system - A field study2017In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 58, 414-423 p.Article in journal (Refereed)
    Abstract [en]

    While in-vehicle eco-driving support systems have the potential to reduce greenhouse gas emissions and save fuel, they may also distract drivers, especially if the system makes use of a visual interface. The objective of this study is to investigate the visual behaviour of drivers interacting with such a system, implemented on a five-inch screen mounted above the middle console. Ten drivers participated in a real world, on-road driving study where they drove a route nine times (2 pre-baseline drives, 5 treatment drives, 2 post-baseline drives). The route was 96 km long and consisted of rural roads, urban roads and a dual-lane motorway. The results show that drivers look at the system for 5-8% of the time, depending on road type, with a glance duration of about 0.6 s, and with 0.05% long glances (amp;gt;2s) per kilometre. These figures are comparable to what was found for glances to the speedometer in this study. Glance behaviour away from the windscreen is slightly increased in treatment as compared to pre- and post-baseline, mirror glances decreased in treatment and post-baseline compared to pre-baseline, and speedometer glances increased compared to pre-baseline. The eco-driving support system provided continuous information interspersed with additional advice pop-ups (announced by a beep) and feedback pop-ups (no auditory cue). About 20% of sound initiated advice pop-ups were disregarded, and the remaining cases were usually looked at within the first two seconds. About 40% of the feedback pop-ups were disregarded. The amount of glances to the system immediately before the onset of a pop-up was clearly higher for feedback than for advice. All in all, the eco-driving support system under investigation is not likely to have a strong negative impact on glance behaviour. However, there is room for improvements. We recommend that eco-driving information is integrated with the speedometer, that optional activation of sound alerts for intermittent information is made available, and that the pop-up duration should be extended to facilitate self-regulation of information intake. (C) 2016 Elsevier Ltd. All rights reserved.

  • 22.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kircher, Katja
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kircher, Albert
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Considerations when calculating percent road centre from eye movement data in driver distraction monitoring2009In: Proceedings of the Fifth International Driving Symposium on Human Factors in Driver Assessment, Training and Vehicle Design, 2009, 132-139 p.Conference paper (Refereed)
    Abstract [en]

    Percent road center (PRC) is a performance indicator which is sensitive to driver distraction. The original definition of PRC is based on fixation data extracted from eye movement recordings, but it has also been suggested that PRC can be determined directly from the gaze data without segmenting it into saccades and fixations. The primary aim of this paper is to investigate if this is the case.

    Naturalistic driving data from a small scale field operational test comprising seven vehicles was used in the evaluation. It was found that PRC time traces based on gaze data and fixation data, respectively, were highly similar (correlation coefficient=0.95, average wavelet semblance=0.84) except for an absolute amplitude difference of about 8%. This indicates that the two approaches can be used interchangeably and that the processing step of segmenting gaze data into saccades and fixations can be left out.

    In addition to this finding, design issues related to the calculation of PRC are investigated. Especially, the impact of gaze cases pointing towards the intersection of the road centre area and the centre rear mirror were investigated. Results lead to conclude that gazes and fixations on the centre rear mirror should be removed from the PRC calculations, as they may negatively influence the correctness of the performance indicator.

  • 23.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kircher, Katja
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Thorslund, Birgitta
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Adell, Emeli
    Trivector Traffic.
    Bicyclists’ visual strategies when conducting self-paced vs. system-paced smartphone tasks in traffic2015In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 41, 204-216 p.Article in journal (Refereed)
    Abstract [en]

    Visual distraction among cyclists interacting with their mobile phones is a growing concern. Yet, very little research has actually investigated how cyclists apply visual strategies and adapt task execution depending on the traffic situation. The aim of this study is to investigate visual behaviour of cyclists when conducting self-paced (initiated by the cyclist) vs. system-paced (initiated by somebody else) smartphone tasks in traffic. Twenty-two cyclists completed a track in real traffic while listening to music, receiving and making calls, receiving and sending text messages, and searching for information on the internet. The route and the types of tasks were controlled, but the cyclists could choose rather freely when and where along the route to carry out the tasks, thus providing semi-naturalistic data on compensatory behaviour. The results show that the baseline and music conditions were similar in terms of visual behaviour. When interacting with the phone, it was found that glances towards the phone mostly came at the expense of glances towards traffic irrelevant gaze targets and also led to shortened glance durations to traffic relevant gaze targets, while maintaining the number of glances. This indicates that visual “spare capacity” is used for the execution of the telephone tasks. The task type influenced the overall task duration and the overall glance intensity towards the phone, but not the mean nor maximum duration of individual glances. Task pacing was the factor that influenced visual behaviour the most, with longer mean and maximum glance durations for self-paced tasks. In conclusion, the cyclists used visual strategies to integrate the handling of mobile phones into their cycling behaviour. Glances directed towards the phone did not lead to traffic relevant gaze targets being missed. In system-paced scenarios, the cyclists checked the traffic more frequently and intensively than in self-paced tasks. This leads to the assumption that cyclists prepare for self-initiated tasks by for example choosing a suitable location. Future research should investigate whether these strategies also exists amongst drivers and other road user groups.

  • 24.
    Ahlström, Mattias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Development of an Attractive Network for Regional Bus Traffic in Dalarna County2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Även om direktbusstrafiken i Dalarnas län redan i dagsläget trafikerar relativt raka och snabba linjesträckningar anser länstrafikbolaget Dalatrafik att det finns potential till att ytterligare sänka restiderna för att locka fler resenärer. Fyra av länets viktigaste direktbusslinjer har därför studerats och för var och en av dessa har ett antal förändringsåtgärder tagits fram. Målet med förändringsåtgärderna har varit att, i första hand, åstadkomma en rakare linjesträckning och utreda hur mycket restiden skulle komma att förändras om bussen istället kör den nya vägen. Utifrån befintlig resandestatistik över hur många resenärer som reser på varje sträcka har den totala tidsbesparingen för samtliga förändringsåtgärder per linje beräknats och detta har givits ett monetärt värde. Genom täckningsanalyser har befolkningen inom upptagningsområdet kring varje hållplats beräknats, detta för att visa hur tillgängligheten till respektive linje förändras efter ett eventuellt införande av de föreslagna åtgärderna.

  • 25.
    Ahmad Termida, Nursitihazlin
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Understanding Individuals' Learning and Decision Processes in a Changing Environment by Using Panel Data2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    When a new transport service is introduced, people have to learn and familiarize themselves with the new service before they decide to adopt it. These processes are developed over time, thus produce dynamics in individuals’ behavioural responses towards the service. This affects the demand of the new service, thus affect revenues. Available studies have examined the factors influencing these responses from microeconomic perspectives. The influence of the theory-based subjective factors has not been examined empirically. Understanding these would assist transport and urban planners to design a better marketing strategy to increase the market share of the new service. A change in seasons affect individuals’ activity-travel decisions, thus produce dynamics in activitytravel patterns in different seasons. Individuals’ constraints, in a form of mandatory activities (working/studying), are influencing individuals’ decisions to participate in day-to-day nonmandatory activities (leisure and routine activities). The interdependency between travel demand, time allocation and mode choice that considers interactions between mandatory and non-mandatory activities, in different seasons is less explored. Understanding these would assist transport planners and operators to manage travel demand strategies across different seasons of the year and provide better transportation systems for all individuals. This thesis includes five papers. Paper I explores individuals’ characteristics of the quick-response and the adopters of the new public transport (PT) service and examines the temporal effects. Paper II investigates the subjective factors influencing a quick-response to the new PT service by proposing a modified attitude-behaviour framework. Paper III and IV analyse the effects of seasonal variations and individuals’ constraints on their day-to-day activity-travel decisions and patterns. Paper V analyses the attrition and fatigue in the two-week travel diary panel survey instrument.

  • 26.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Attrition and Fatigue in a Four Waves of Two-Week Travel Diary: A Case Study in Stockholm, SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    This paper describes a four-wave panel survey design and implementation collected on individual level, consisting of three survey’s instrument namely, self-reported two-week travel diary, on-line psychological questionnaire, and self-reported mental map-related questions. The panel survey is built with the aim to examine individuals’ behavioural changes when a new tram extension line in western sub-urban areas of Stockholm, Sweden, was introduced in October 2013. The survey duration took approximately seven months’ period and the data collected covers all four different seasons of the year, which make it wealth of information. The analysis of attrition and fatigue was done on the two-week travel diary survey instrument only. It is found that the overall attrition rate is 34.3% of the total participants (102 individuals) in the Wave 1 survey, which is considered large. The attrition rate between consecutive waves, however, is considered low which is within the range of 7% to 10%. Based on the binary logit models, there are no systematic tendencies of the dropouts’ characteristics from wave to wave to be found, indicating attrition is purely random. There is no correlation between immobile days and missing trips per day are to be found between-waves. The results of the binary logit model on missing trip show that personal attributes, temporal factors (e.g. weekdays and waves) and travel characteristics (e.g. home-based trip, trip purpose, travel distance and number of inter-modal transfers) significantly affect the missing trip but no indication of fatigue appears.

  • 27.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Subjective Factors Influencing Individual's Response to a New Public Transport ServiceManuscript (preprint) (Other academic)
    Abstract [en]

    The timing and nature of people’s responses can be expected to vary when a new element enter their environment. For example, when an individual is provided with a new or modified transport service. This time-scale of behavioural responses will affect the patronage of, and short- and long-term demands on the new service over time. Understanding the underlying factors that influence an individual’s response over time to a new or modified transport service would enable us to identify trigger factors that make the new service attractive from an individual’s point of view. Chatterjee (2001) and Douglas (2003) argued that motives other than instrumental factors related to public transport use, such as attitudes, awareness, travel habits and learning processes, can influence individual responses over time to changes in the travel environment. Unfortunately, despite their importance, there have been few studies that examined this argument empirically. To address this research gap, this paper aims to investigate the influences of subjective factors on individuals’ responses to the introduction of a modified public transport (PT) service over time by proposing and testing an alternative model that modifies the theory of planned behaviour (TPB) model framework. This paper also aims to investigate the behavioural change in terms of attitudes and perceptions on individuals’ resources and constraints in using a modified PT service over time after its introduction. The case study involves the new extension of a tram line connecting the suburbs of Alvik and Solna Centrum in Stockholm, Sweden. Four waves of a panel survey were conducted with 96 individuals who lived along the new service, from just before the new service was introduced and until seven months after its introduction. A structural equation modelling technique was used to estimate the relationships between behavioural constructs and panel data, then incorporate them into a discrete choice model. The results show that intention influences individual’s quick-response choice. The panel analysis shows that past behaviour in using the new service influenced current behaviour, and that perceived walking distance in using the service consistently influenced the frequency of using the new service over time.

  • 28.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Liu, Chengxi
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. VTI.
    Understanding Seasonal Variation in Individual's Activity Participation and Trip Generation by Using Four Consecutive Two-Week Travel DiaryManuscript (preprint) (Other academic)
    Abstract [en]

    This paper explores the interactions between travel demand, time allocation and mode choice in different seasons by jointly modeling the work and/or study, routine and leisure activity-travel engagements of 67 individuals in Stockholm, Sweden. A longitudinal panel two-week travel diary data collected in four consecutive waves over a span of seven months period that covers all four different seasons; autumn, winter, spring and summer, were analysed by using simultaneous Tobit models. The model was applied to explore the interactions among each activity-travel indicator, and individuals’ unique characteristics and endogeneity in activity-travel engagements between different seasons were also considered in the model system. The results of models reveal clear trade-offs between mandatory activities (work and/or study) and non-mandatory activities (routine and leisure), regardless of any seasons, although the magnitudes vary between seasons. There is also a positive mutual endogeneity relationship between number of trips and activity duration within the same activity type. The trade-offs between work and/or study trips towards routine and leisure trips are larger in winter and spring respectively, than in other seasons. It is also found that mode effects on travel time for conducting mandatory activity are much larger in spring than in other seasons. However, the effects of public transport and slow modes on travel time for leisure activities are much larger in summer than in other seasons.

  • 29.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Franklin, Joel P.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Examining the effects of out-of-home and in-home constraints on leisure activity participation in different seasons of the year2016In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, 1-25 p.Article in journal (Refereed)
    Abstract [en]

    Using multi-day, multi-period travel diaries data of 56 days (four waves of two-week diaries) for 67 individuals in Stockholm, this study aims to examine the effects of out-of-home and in-home constraints (e.g. teleworking, studying at home, doing the laundry, cleaning and taking care of other household member[s]) on individuals’ day-to-day leisure activity participation decisions in four different seasons. This study also aims to explore the effects of various types of working schedules (fixed, shift, partial- and full-flexible) on individuals’ decisions to participate in day-to-day leisure activities. A pooled model (56 days) and wave-specific models (14 days in each wave) are estimated by using dynamic ordered Probit models. The effects of various types of working schedules are estimated by using 28 days of two waves’ data. The results show that an individual’s leisure activity participation decision is significantly influenced by out-of-home work durations but not influenced by in-home constraints, regardless of any seasons. Individuals with shift working hours engage less in day-to-day leisure activities than other workers’ types in both spring and summer seasons. The thermal indicator significantly affects individuals’ leisure activity participation decisions during the autumn season. Individuals exhibit routine behaviour characterized by repeated decisions in participating in day-to-day leisure activities that can last up to 14 days, regardless of any seasons.

  • 30.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Susilo, Yusak O.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Franklin, Joel P.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Observing dynamic behavioural responses due to the extension of a tram line by using panel survey2016In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 86, 78-95 p.Article in journal (Refereed)
    Abstract [en]

    Using a four-wave panel survey of individuals' trips and psychological attributes collected among residents along a new tram line extension in the city of Stockholm, Sweden, this study aims to investigate factors that determine the individuals' learning and decision-making processes in using a new transport option. This includes investigating which group of travellers have used the new tram extension earlier than others, and integrated the tram extension as a part of their daily travel patterns. This paper also describes the design and construction of the four-wave panel data collection, which was collected from two weeks before and up to seven months after the opening of the new option. Descriptive analysis shows that within a seven-month period, 79% of the respondents tried the new tram extension but only 14.9% of them adopted the new option as their daily travel mode. During the observed period, about 49.3% of the respondents migrated between travel modes for non-discretionary trips. Further multivariate analysis shows that middle-income travellers and travellers who owned car(s) used the new tram extension earlier than others. The effect of past experience on the current use of the tram extension on a day-to-day basis was also examined by using a mixed logit model with panel data. The purpose of the model is to examine whether individuals' daily experiences with the new tram extension that result from repeated previous choices would affect their decisions to maintain using the new option in subsequent waves.

  • 31.
    Ahmadkhani, Ali
    Jönköping University, Jönköping International Business School, JIBS, Centre of Logistics and Supply Chain Management (CeLS).
    Reverse side of logistics in automotive industry2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The third party logistics (3PL) providers play remarkable function in the business world of today’s; therefore, to investigate their challenges will be a valuable study. This study has investigated the challenges and ways to manage these challenges by a 3PL provide company. The achieved results are in coordination with the literature to some extent.The most important challenges are cost, flexibility, professionalism, and quality ofservices. In managing the 3PL challenges, theoretical views mostly tend to apply distinguished approaches, tools and algorithms. Meanwhile, in the case study, it has not introduced any specific approaches or algorithm, but mostly proposed the traditional approaches, such as doing researches and investigations, or Motivation Management. 

  • 32.
    Ahmed, Bassam
    Gotland University, School of the Humanities and Social Science.
    Förbättring av kvalitet och samarbete i tågtrafiken: ett förbättringsprojekt till tågtrafikens intressenter2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Passengers get dissatisfied because of poor communication and bad co-operation between railway companies. The alternative solutions to the passengers at the traffic disruptions are not the best, which causes traveler dissatisfaction. The risk is that passengers choose other ways of transport.

    Each transport organizer is responsible for the passengers. The form of the operating agreements between transport authorities and rail companies creates a structure for the responsibilities of the different components. This is also part of the problem leading to unhappy customers.

    I have studied this problem through interviews and surveys at DSB Småland where I work asa traffic controller. Jönköping County relates to the DSB Småland with a contract. I have hadthe opportunity to interview dispatchers in Jönköping County and to take part of customer complaints. But the big picture is not only about DSB Småland and Jönköping County. Consequently I have chosen to also include opinions from the DB-Regional traffic.

    Dedicated people from the different organizations have helped me to collect the information needed. Documentation of the selected organization the DSB Småland and my personal experience has helped me to formulate some conclusions:

    • Individual responsibility and mutual responsibility across organizational boundaries is important and it does not exist today. That may result in each organization working to save itself without looking at the big picture. Greater individual responsibility and collective responsibility across organizational boundaries will lead to focus on the passengers and it can result in saving resources.
    • Collaboration between organizations, which does not exist today, is needed. Without organized cooperation, the risk will be that each organization can be held to the agreement with the county traffic without any further interest towards the traveler. The more cooperation between the organizations, the more satisfied customers.
    • Communication between the organizations on the problems encountered needs to be improved. Poor communication between organizations leads to waste of environmental resources and other assets, and leads to dissatisfied customers. Better communication gives all organizations the possibility of increasing the number of passengers, to save resources and leads to increased sustainability in train traffic.

    It takes exchange of experiences between railway companies to achieve better quality of train services, more sustainable rail services to all, stronger collaboration and deep and straightforward communication.

  • 33.
    Ahmed, Mohamed
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Maxamed, Maxamed
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Modell för beslutsfattande avseende hållbar logistik: I både tjänsteföretag och tillverkningsföretag2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In any successful business, it is important to establish a dedicated management with the ability to make critical and sustainable decisions. Policy makers are a major and perhaps the biggest factor in a company and usually it is the managers who are also decision-makers. There are a number of aspects to keep in mind in order to make as appropriate decisions as possible, which can be anything from personality traits to how market analytic decision-maker is.

    The purpose of this thesis is to develop a model for decision-making on sustainable logistics, in both manufacturing companies and service companies in Sweden. Literature studies and interviews are conducted in order to answer the purpose. Through the literary study, significant factors can be found, for example crisis management and trust, prejudice and character traits.

    This work’s empirical material is based on interviews in four different organizations regarding their decision making and their approach to sustainable logistics. These organizations are both service and manufacturing companies, which gives the work a breadth and generalizability.

    The identified factors that are developed through the case studies include emotionality and rationality, trust, and transparency. Several factors in the literature are clearly consistent with the significant factors in the study result. The factors that both the service and manufacturing companies have in mind when making decisions regarding sustainable logistics are presented in the results. The conclusion of this study is a model that visualizes the factors one should keep in mind when making decisions regarding sustainable logistics. These factors are trust, supplier selection, unity, facts, transparency and empathy. Based on these factors, any company with a dedication and commitment to long-term decision-making processes can make wise and effective assessments.

  • 34.
    Aid, Graham
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Industrial Ecology Methods within Engagement Processes for Industrial Resource Management2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The global use of resources such as materials, energy, and water has surpassed sustainable levels by many accounts.  The research presented here was explicitly normative in its aim to improve the understanding of, and make sustainable change toward highly systemic issues of resource management.  The core methods chosen to work toward this aim were bottom up action research procedures (including stakeholder engagement processes) and industrial ecology analysis tools.  These methods were employed and tested in pragmatic combination through two of the author’s case study projects. The first case study, performed between 2009 and 2012, employed a multi-stakeholder process aimed at improving the cycling of construction and demolition waste in the Stockholm region.  The second case study produced a strategic tool (Looplocal) built for facilitating more efficient regional industrial resource networks. While the highly participative aim of the cases required a larger contribution of resources than that of more closed studies, it is arguable that the efficacy of approaching the project aims is improved through their employment. 

  • 35.
    Aid, Graham
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Brandt, Nils
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Lysenkovac, Mariya
    Smedberg, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Looplocal: a Heuristic Visualization Tool for the Strategic Facilitation of Industrial Symbiosis2012In: Greening of Industry Netowrk Proceedings / [ed] Leo Baas, 2012Conference paper (Refereed)
    Abstract [en]

    Industrial symbiosis (IS) developments have been differentiated as ‘self organized’, ‘facilitated’, and ‘planned’. This article introduces a tool that has been built with objectives to support the strategic facilitation of IS. ‘Looplocal’ is a visualization tool built to assist in 1) the identification of regions prone to new industrial symbiosis activities 2) market potential exchanges to key actors and 3) assist aspiring facilitators to assess the various strategies and social methodologies available for the initial phases of a facilitated industrial symbiosis venture. This tool combines life cycle inventory (LCI) data, waste statistics, and national industrial data (including geographic, activity, economic, and contact information) to perform a heuristic analysis of raw material and energy inputs and outputs (wastes). Along with an extensive list of ‘waste to raw material’ substitutions (which may be direct, combined, or upgraded) gathered from IS uncovering studies, IS organizations, and waste and energy professionals; heuristic regional output to input ‘matching’ can be visualized. On a national or regional scale the tool gives a quick overview of what could be the most interesting regions to prioritize resources for IS facilitation. Focusing in on a regional level, the tool visualizes the potential structure of the network in that region (centralized, decentralized, or distributed), allowing a facilitator to adapt the networking approach correspondingly. The tool also visualizes potential IS transfer information, along with key stakeholder data. The authors have performed a proof of concept run of this tool in the ‘industrial disperse’ context of Sweden. In its early stages of application, the method has proven capable of identifying regions prone to the investment of facilitators’ resources. The material focus and custom possibilities for the tool show potential for a wide spectrum of potential facilitators: from waste management companies (using the tool as a strategic market analysis tool) to national or regional authorities looking to lower negative environmental impacts, to ‘sustainable’ industry sectors looking to strengthen market positioning. In conjunction with proper long term business models, such a tool could be reusable itself over the evolution of facilitation activities and aims.

  • 36.
    Ait Ali, Abderrahman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Lindberg, Per Olov
    KTH.
    Nilsson, Jan-Eric
    Eliasson, Jonas
    Aronsson, Martin
    Disaggregation in Bundle Methods: Application to the Train Timetabling Problem2017Conference paper (Refereed)
    Abstract [en]

    Bundle methods are often used to solve dual problems that arise from Lagrangian relaxations of large scale optimization problems. An example of such problems is the train timetabling problem. This paper focuses on solving a dual problem that arises from Lagrangian relaxation of a train timetabling optimization program. The dual problem is solved using bundle methods. We formulate and compare the performances of two different bundle methods: the aggregate method, which is a standard method, and a new, disaggregate, method which is proposed here. The two methods were tested on realistic train timetabling scenarios from the Iron Ore railway line. The numerical results show that the new disaggregate approach generally yields faster convergence than the standard aggregate approach.

  • 37.
    Akililu, Meaza Negash
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Verification of Rural Traffic Simulator, RuTSim 22012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Traffic models based on micro-simulation are becoming increasingly important as traffic analysistools. Due to the detailed traffic description, different micro-simulation models are needed tosimulate different traffic environments. The Rural Traffic Simulator, RuTSim, is a unique microtrafficsimulation model for traffic on rural roads. RuTSim is developed at VTI with support fromthe Swedish Transport Administration. Currently, a new version of the RuTSim model has beenimplemented based on the earlier one but with some enhancements. Due to these enhancements,the new implementation of RuTSim should be verified before being used to analyze real worldproblems.

    In this master’s thesis, a verification of the new implementation of the RuTSim model, RuTSim 2,has been carried out. This paper includes a description of traffic micro-simulation models forrural roads in general and a description of RuTSim model in particular. Common verificationtechniques of the simulation models are also discussed in this study.

    Based on the theoretical assessments, a model-to-model comparison verification scheme isselected to verify the RuTSim 2 model. That is, the model verification is performed by comparingthe simulation outputs from RuTSim 2 to the old version of RuTSim (RuTSim 1), since RuTSim1 is well verified and calibrated. Statistical hypothesis tests are used to check whether the meanand standard deviation differences of the simulation outputs between the two simulators aresignificant or not.

    Based on the verification results, the new version of the RuTSim model has comparable modelingof vehicle-vehicle and vehicle-infrastructure interactions as the old version. Furthermore, thehypothesis test results show that the differences of the mean simulation results of the twosimulators are not significant. Therefore, the new implementation of RuTSim model, RuTSim 2,has been proven to be equivalent model as the old version.

  • 38.
    Alam, Assad
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Fuel-Efficient Heavy-Duty Vehicle Platooning2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The freight transport industry faces big challenges as the demand for transport and fuel prices are steadily increasing, whereas the environmental impact needs to be significantly reduced. Heavy-duty vehicle (HDV) platooning is a promising technology for a sustainable transportation system. By semi-autonomously governing each platooning vehicle at small inter-vehicle spacing, we can effectively reduce fuel consumption, emissions, and congestion, and relieve driver tension. Yet, it is not evident how to synthesise such a platoon control system and how constraints imposed by the road topography affect the safety or fuel-saving potential in practice.

    This thesis presents contributions to a framework for the design, implementation, and evaluation of HDV platooning. The focus lies mainly on establishing fuel-efficient platooning control and evaluating the fuel-saving potential in practice. A vehicle platoon model is developed together with a system architecture that divides the control problem into manageable subsystems. Presented results show that a significant fuel reduction potential exists for HDV platooning and it is favorable to operate the vehicles at a small inter-vehicle spacing. We address the problem of finding the minimum distance between HDVs in a platoon without compromising safety, by setting up the problem in a game theoretical framework. Thereby, we determine criteria for which collisions can be avoided in a worst-case scenario and establish the minimum safe distance to a vehicle ahead. A systematic design methodology for decentralized inter-vehicle distance control based on linear quadratic regulators is presented. It takes dynamic coupling and engine response delays into consideration, and the structure of the controller feedback matrix can be tailored to the locally available state information. The results show that a decentralized controller gives good tracking performance and attenuates disturbances downstream in the platoon for dynamic scenarios that commonly occur on highways. We also consider the problem of finding a fuel-efficient controller for HDV platooning based on road grade preview information under road and vehicle parameter uncertainties. We present two model predictive control policies and derive their fuel-saving potential. The thesis finally evaluates the fuel savings in practice. Experimental results show that a fuel reduction of 3.9–6.5 % can be obtained on average for a heterogenous platoon of HDVs on a Swedish highway. It is demonstrated how the savings depend on the vehicle position in the platoon, the behavior of the preceding vehicles, and the road topography. With the results obtained in this thesis, it is argued that a significant fuel reduction potential exists for HDV platooning.

  • 39. Alam, Assad
    et al.
    Besselink, Bart
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Turri, Valerio
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Mårtensson, Jonas
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Heavy-Duty Vehicle Platooning for Sustainable Freight Transportation A COOPERATIVE METHOD TO ENHANCE SAFETY AND EFFICIENCY2015In: IEEE CONTROL SYSTEMS MAGAZINE, ISSN 1066-033X, Vol. 35, no 6, 34-56 p.Article in journal (Refereed)
    Abstract [en]

    The current system of global trade is largely based on transportation and communication technology from the 20th century. Advances in technology have led to an increasingly interconnected global market and reduced the costs of moving goods, people, and technology around the world [1]. Transportation is crucial to society, and the demand for transportation is strongly linked to economic development. Specifically, road transportation is essential since about 60% of all surface freight transportation (which includes road and rail transport) is done on roads [2]. Despite the important role of road freight transportation in the economy, it is facing serious challenges, such as those posed by increasing fuel prices and the need to reduce greenhouse gas emissions. On the other hand, the integration of information and communication technologies to transportation systems-leading to intelligent transportation systems-enables the development of cooperative methods to enhance the safety and energy efficiency of transportation networks. This article focuses on one such cooperative approach, which is known as platooning. The formation of a group of heavy-duty vehicles (HDVs) at close intervehicular distances, known as a platoon (see Figure 1) increases the fuel efficiency of the group by reducing the overall air drag. The safe operation of such platoons requires the automatic control of the velocity of the platoon vehicles as well as their intervehicular distance. Existing work on platooning has focused on the design of controllers for these longitudinal dynamics, in which simple vehicle models are typically exploited and perfect environmental conditions, such as flat roads, are generally assumed. The broader perspective of how platooning can be effectively exploited in a freight transportation system has received less attention. Moreover, experimental validations of the fuel-saving potential offered by platooning have typically been performed by reproducing the perfect conditions as assumed in the design of the automatic controllers. This article focuses on these two aspects by addressing the following two objectives.

  • 40. Al-ani, Neeran
    et al.
    Boutros, Mireille
    Linköping University.
    Flerpatientbesök – ett förbättringsförslag baserat på en analys av den dagligaverksamheten vid vårdcentralen Cityhälsan Söder: En kartläggning på Blodtrycksmottagning och Astma/KOL- mottagning med hjälp av Lean2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Östergötland County Council has begun to implement “Lean-Thinking" in healthcare service. Staff at healthcare service has experienced new challenges. Health care quality cannot anymore be measured only by medical treatment results, other factors are of importance, for example accessibility.

    The management of the health centre “Cityhälsan Söder” wished to identify problems that affect patient flow and requested proposals for improvements which could increase the number of patients cared for at Blood Pressure-department and Asthma/COL- department.

    For the mapping of the activities performed by a nurse during a working day, two data collection methods were used: observation and survey. Collected data were analysed in relation to the frame of reference concerning theories of Lean healthcare and logistics. Focus in the identification of problems was to improve the utilization of nursing time to allow more patient visits. 

    In the analysis eight types of wastes are especially used: overproduction, waiting, transportation, extra-processing, inventory, motion, defects and non-utilised skills. From the healthcare logistics point of view, the cancelations problem, lack of resources and matching capacity with demand was also analysed.

    To increase staff knowledge of how service may work better it was suggested to take advantage of the staff's creativity by expanding the personnel’s perception of patient flow in order to match capacity with demand. Other proposals concerned waiting-list management, which aims to introduce direct time booking of upcoming patient visits at both departments, freeing administrative time that can be spent to accommodate more patients. To standardize medical examinations on Asthma/COL-departments is also a proposal.

    IT-solutions for both departments may also create opportunities for more patient visits. A film that prepares the patient by teaching the correct blowing technique for the visit on Asthma/COL-department may accelerate medical examinations and free time that can be used better.

  • 41.
    Albrecht, Martin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Enabling socio-technical transitions – electric vehicles and high voltage electricity grids as focal points of low emission futures2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Today humankind is facing numerous sustainability challenges that require us to question CO2 intensive practices like those present in the transport and energy sector. To meet those challenges, many countries have adopted ambitious climate targets. Achieving such targets requires an understanding of the wider socio-technical context of transitions. The aim of this licentiate thesis is therefore to analyse such socio-technical transitions towards low-emission futures enabled by the electrification of passenger cars and high voltage grid development.

    A combination of different transitions theories (for ex. Multi-level perspective and Technological innovation systems) and institutional theory has been used. To reach the aim paper I analyses the climate impacts of electric vehicles (EVs) and policy measures to achieve a breakthrough scenario for EVs. The results show that a mixture of short and long term policies are needed that take into account the technology development stage and behavioural aspects of EV adopters. Paper II addresses the need to include the high voltage transmission grid and its planning procedures as a central part of debates on transitions. Therefore the opportunities, challenges and reasons for conflict in the established regime are studied. The results show that in order to achieve a sustainable grid development regime, it is necessary to spend time on achieving legitimacy and social sustainability. The third paper uses semi-structured expert interviews and focuses on innovation dynamics for EV adoption. By focusing on dynamics instead of single policy measures, it is possible to grasp interactions within a niche, but also in between a niche, regime and landscape. The results show that strong initial technology legitimacy was needed to start substantial innovation dynamics. This could be further strengthened with a strong and broad coalition of actors. Both those factors led, if present, to an improved variety and match of policy instruments.

    As such this thesis has shown that transitions are not just about technology or policy instruments as such but about the dynamics and processes needed to enable them. This can be relevant in other transitions that otherwise may underestimate the importance of these components.

  • 42.
    Albrecht, Martin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    System innovation dynamics around electric vehicles. The cases of Norway, Denmark and Sweden.Manuscript (preprint) (Other academic)
    Abstract [en]

    This paper focuses on the comparison of electric car innovation patterns in Norway, Sweden and Denmark. Doing so, it takes a closer look at what the most essential dynamics in the systems were over time and what enabled those dynamics. The main research aim is to contribute to a wider understanding of why Norway is so much ahead of Sweden and Denmark in electric car adoption. The purpose is also to adopt a perspective that goes beyond a mere focus on economic policy instruments. In order to do so different theory elements are combined in a framework. These elements stem from the transition theory literature field, especially the technological innovation system (TIS) and the multi-level perspective (MLP). This combination allows analysing the development behind a dynamic, not just when it comes to an innovation itself but also with regards to the established regime. The data is gathered through analysis of existing documents and data as well as a series of 27 expert interviews conducted in the three case countries. The findings suggest that there are important differences in transition patterns that can account for the electric vehicle (EV) diffusion situation we can find nowadays in the three Nordic countries. An important stepping stone was the need for a very strong legitimacy of the original EV vision that is also anchored in a coordinated, sector overarching coalition of actors that thinks strategically and long term. Moreover some general beneficial dynamics could be identified across the countries in question. In Norway these beneficial dynamics can be summarised as a systems motor, in Denmark as a failed entrepreneurial motor that shifted towards a constrained municipal motor and in Sweden as a loosely, coordinated and weaker version of a systems motor.

  • 43.
    Albrecht, Martin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Nilsson, Måns
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms). Stockholm University, Stockholm Environment Institute.
    Åkerman, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Electrification of vehicles – policy drivers and impacts in two scenarios.2013In: Grid Integration of Electric Vehicles in Open Electricity Markets / [ed] Qiuwei Wu, John Wiley & Sons, 2013Chapter in book (Refereed)
    Abstract [en]

    This chapter examines current policy drivers of battery electric vehicles (EVs) and plug-in hybrid EVs, the current and anticipated impacts on carbon emissions, as well as what potential role policy can play in enhancing the innovation system and market development around such vehicles in the future. We start with a policy review of key targets in the Nordic countries and the EU, up to 2030, and discuss to what extent they are consistent with industry and expert estimates of how the systems can grow. On the basis of this, the second part elaborates two simple scenarios of EV development in the EU: one breakthrough expansion scenario and one incremental expansion scenario. Building on that is an analysis of the climate impacts of the two scenarios, given different assumptions relating to, for example, electricity production as well as EV penetration in the fleet. The third part examines what policy drivers might be needed to enable the breakthrough scenario, using a technological innovation systems perspective to describe the needed processes, drivers and developments.

  • 44.
    Aldin, Niklas
    Linköping University, Department of Management and Engineering, Logistics Management. Linköping University, The Institute of Technology.
    The Luna Case within Bergman & Beving Tools: Changes in Logistics Management2002Report (Other academic)
    Abstract [en]

    Companies conducting business in multiple marketing channels need logistics and IT solutions that support their wide array of strategy and operations. Those, and other firms, do not solely rely on new concepts but also on continuously developing their businesses in the interaction between marketing and logistics. This case study will show on these aspects - how marketing and logistics may be integrated in such a channel environment by continuously developing the business as well as through new approaches in information technology - electronic commerce.

    The Luna case Within Bergman & Beving Tools illustrates the development of a medium sized distributor from catalogue based firm to flow co-ordinator in a group constellation, a change from a single steady going to a multiple requirement demanding marketing channel. Luna is a transaction intensive distributor of tools and machinery equipment with long experience in logistics and information technology. The company is guarantor for assortment quality, fast and reliable logistics through sophisticated IT solutions as well as value added competence in its trade relations with dealers and end customers. Independent dealers and end customers are found in Nordic industrial, construction, engineering, administration and consumer sectors. Bergman & Beving Tools is parent company to seven distributors of which Luna is the largest.

    To start with, this case describes the background development of the business in the fields of marketing, logistics and information technology until 1993. The second part between 1993 and 2001 describes how the marketing agenda has changed, how electronic commerce has been used to develop the business and changes in logistics, both on operational and strategic levels. As a whole the case describes changes in logistics management and how that has interacted with market development.

  • 45.
    Aldén, Anna
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Odebo, Stina
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    The use of ground equipment at airports2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    För att flygplatser ska kunna ha så hög kapacitet som möjligt krävs effektivisering av alla delar av flygplatsverksamheten. Denna studie har identifierat problem och utvecklingsområden av användningen av markutrustning på flygplatser. I studien har det även analyserats effektiviseringsmöjligheter. Några exempel på problem och utvecklingsområden som funnits är att utrustningen är utspridd på flygplatsen och att det finns för mycket utrustning. Ett av lösningsförslagen som föreslås i rapporten är att en tredjepartsaktör äger all markutrustning på flygplatsen och sedan bedriver uthyrning av utrustningen till användarna.

  • 46.
    Alemu, Beakal Tadesse
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Collocation of Infrastructuresin Stockholm Airport City: Collocation of infrastructures to foster implementation ofnew transportation systems2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 47.
    Alexandra Markovic, Markovic
    et al.
    Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    Arvid, Edforss
    Jönköping University, School of Engineering, JTH, Mechanical Engineering.
    An evaluation of current calculations for safety stock levels2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 48.
    Alfonsetti, Elisabetta
    et al.
    KTH, School of Electrical Engineering (EES).
    Weeraddana, P. C.
    Fischione, Carlo
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Min-max fair car-parking slot assignment2015In: Proceedings of the WoWMoM 2015: A World of Wireless Mobile and Multimedia Networks, IEEE conference proceedings, 2015Conference paper (Refereed)
    Abstract [en]

    Empirical studies show that cruising for car parking accounts for a non-negligible amount of the daily traffic, especially in central areas of large cities. Therefore, mechanisms for minimizing traffic from cruising directly affect the dynamics of traffic congestions. One way to minimizing cruising traffic is efficient car-parking-slot assignment. Usually, the related design problems are combinatorial and the worst-case complexity of optimal methods grows exponentially with the problem sizes. As a result, almost all existing methods for parking slot assignment are simple and greedy approaches, where each car or the user is assigned a free parking slot, which is closer to its destination. Moreover, no emphasis is placed to optimize any form of fairness among the users as the a social benefit. In this paper, the fairness as a metric for modeling the aggregate social benefit of the users is considered. An algorithm based on Lagrange duality is developed for car-parking-slot assignment. Numerical results illustrate the performance of the proposed algorithm compared to the optimal assignment and a greedy method.

  • 49.
    Alfredsson, Nina
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Angvarson, Josefin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    An analysis of the robustness of SAS crew schedules2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Scandinavian Airlines (SAS) är nordens största flygbolag och har en besättning på 5 000 personer med baser i Danmark, Norge och Sverige. SAS besättningsscheman för kabinpersonal med bas Stockholm samt piloter med samma bas och kvalifikationer för flygplanstypen Boeing 737 har analyserats. Genomförda förändringar efter att scheman publicerats under 2013 och 2014 har kartlagts. Förändringarna har utretts för att fastställa hur stor andel av ett schema som genomförs som planerat. Vidare har ett mätetal som även tar hänsyn till antalet ändringar som sker från planerad ledighet och sjukdom till någon form av produktion tagits fram, mätetalet kallas förändringskvot. Andelen avvecklat enligt plan och förändringskvoten är beräknade per produktionsdag. Mätetalens resultat är relativt jämna för 2013 och 2014. År 2013 avvecklades i genomsnitt 75 % av panerade produktionsdagar och förändringskvoten utgjorde i genomsnitt 30 %. Motsvarande siffror för år 2014 var 77 % och 29 %.

  • 50.
    Algers, Staffan
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Even more possibilities to combine demand models2011Conference paper (Other academic)
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