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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.
    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.

  • 5.
    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.

  • 6.
    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 %.

  • 7.
    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.

  • 8.
    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.  

  • 9.
    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.

  • 10.
    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.

  • 11.
    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.

  • 12.
    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.

  • 13.
    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.

  • 14. 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.

  • 15.
    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.

  • 16.
    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.

  • 17.
    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 %.

  • 18.
    Allström, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Highway Traffic State Estimation and Short-term Prediction2016Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Traffic congestion is increasing in almost all large cities, leading to a number of negative effects such as pollution and delays. However, building new roads is not a feasible solution. Instead, the use of the existing road network has to be optimized, together with a shift towards more sustainable transport modes. In order to achieve this there are several challenges that needs to be addressed. One challenge is the ability to provide accurate information about the current and future traffic state. This information is an essential input to the traffic management center and can be used to influence the choices made by the travelers. Accurate information about the traffic state on highways, where the potential to manage and control the traffic in general is very high, would be of great significance for the traffic managers. It would help the traffic managers to take action before the system reaches congestion and limit the effects of it. At the same time, the collection of traffic data is slowly shifting from fixed sensors to more probe based data collection. This requires an adaptation and further development of the traditional traffic models in order for them to handle and take advantage of the characteristics of all types of data, not just data from the traditionally used fixed sensors.

    The objective of this thesis is to contribute to the development and implementation of a model for estimation and prediction of the current and future traffic state and to facilitate an adaptation of the model to the conditions of the highway in Stockholm. The model used is a version of the Cell Transmission Model (CTM-v) where the velocity is used as the state variable. Thus, together with an Ensemble Kalman Filter (EnKF) it can be used to fuse different types of point speed measurements. The model is developed to run in real-time for a large network. Furthermore, a two-stage process used to calibrate the model is implemented. The results from the calibration and validation show that once the model is calibrated, the estimated travel times corresponds well with the ground truth travel times collected from Bluetooth sensors.

    In order to produce accurate short-term predictions for various networks and conditions it is vital to combine different methods. We have implemented and evaluated a hybrid prediction approach that assimilates parametric and non-parametric short-term traffic state prediction. To predict mainline sensor data we use a neural network, while the CTM-v is ran forward in time in order to predict future traffic states. The results show that both the hybrid approach and the CTM-v prediction without the additional predicted mainline sensor data is superior to a naïve prediction method for longer prediction horizons.

  • 19.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Archer, Jeffery
    Sweco Infrastructure, Sweden.
    Bayen, Alexandre
    University of California, Berkeley, USA.
    Blandin, Sebastian
    University of California, Berkeley, USA.
    Butler, Joe
    California Center for Innovative Transportation. USA.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Koutsopoulose, Haris N
    Royal Institute of Technology (KTH), Sweden.
    Lundgren, Jan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rahmani, Mahmood
    Royal Institute of Technology (KTH), Sweden.
    Tossavainen, Olli-Pekka
    NAVTEQ LLC, USA.
    Mobile Millennium Stockholm2011In: 2nd International Conference on Models and Technologies for Intelligent Transportation Systems, 2011Conference paper (Other academic)
  • 20.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Barceló, Jaume
    Department of Statistics and Operations Research, Universitat Politècnica de Catalunya.
    Ekström, Joakim
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Grumert, Ellen
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Traffic management for smart cities2016In: Designing, developing, and facilitating smart cities: urban design to IoT solutions. Part III / [ed] Vangelis Angelakis, Elias Tragos, Henrich C. Pöhls, Adam Kapovits and Alessandro Bassi, Switzerland: Springer, 2016, 211-240 p.Chapter in book (Other academic)
    Abstract [en]

    Smart cities, participatory sensing as well as location data available in communication systems and social networks generates a vast amount of heterogeneous mobility data that can be used for traffic management. This chapter gives an overview of the different data sources and their characteristics and describes a framework for utilizing the various sources efficiently in the context of traffic management. Furthermore, different types of traffic models and algorithms are related to both the different data sources as well as some key functionalities of active traffic management, for example short-term prediction and control.

  • 21.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Sweco TransportSystem, Stockholm, Sweden.
    Bayen, Alexandre M.
    University of California Berkeley, USA.
    Fransson, Magnus
    Linköping University. Sweco TransportSystem, Stockholm, Sweden.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Patire, Anthony D.
    University of California Berkeley, USA.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Sandin, Mats
    Linköping University.
    Calibration Framework based on Bluetooth Sensors for Traffic State Estimation Using a Velocity based Cell Transmission Model2014In: Transportation Research Procedia, ISSN 2352-1465, Vol. 3, 972-981 p.Article in journal (Refereed)
    Abstract [en]

    The velocity based cell transmission model (CTM-v) is a discrete time dynamical model that mimics the evolution of the traffic velocity field on highways. In this paper the CTM-v model is used together with an ensemble Kalman filter (EnKF) for the purpose of velocity sensor data assimilation. We present a calibration framework for the CTM-v and EnKF. The framework consists of two separate phases. The first phase is the calibration of the parameters of the fundamental diagram and the second phase is the calibration of demand and filter parameters. Results from the calibrated model are presented for a highway stretch north of Stockholm, Sweden.

  • 22.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ekström, Joakim
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ringdahl, Rasmus
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Bayen, Alexandre M.
    Department of Civil and Environmental Engineering, University of California.
    Patire, Anthony D.
    Department of Civil and Environmental Engineering, University of California.
    A hybrid approach for short-term traffic state and travel time prediction on highways2016In: TRB 95th annual meeting compendium of papers, 2016Conference paper (Refereed)
    Abstract [en]

    Traffic management and traffic information are essential in urban areas, and require a good knowledge about both the current and the future traffic state. Both parametric and non-parametric traffic state prediction techniques have previously been developed, with different advantages and shortcomings. While non-parametric prediction has shown good results for predicting the traffic state during recurrent traffic conditions, parametric traffic state prediction can be used during non-recurring traffic conditions such as incidents and events. Hybrid approaches, combining the two prediction paradigms have previously been proposed by using non-parametric methods for predicting boundary conditions used in a parametric method. In this paper we instead combine parametric and non-parametric traffic state prediction techniques through assimilation in an Ensemble Kalman filter. As non-parametric prediction method a neural network method is adopted, and the parametric prediction is carried out using a cell transmission model with velocity as state. The results show that our hybrid approach can improve travel time prediction of journeys planned to commence 15 to 30 minutes into the future, using a prediction horizon of up to 50 minutes ahead in time to allow the journey to be completed.

  • 23.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ekström, Joakim
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ringdahl, Rasmus
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Bayen, Alexandre M.
    Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA.
    Patire, Anthony D.
    Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA.
    Hybrid Approach for Short-Term Traffic State and Travel Time Prediction on Highways2016In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 2554, 60-68 p.Article in journal (Refereed)
    Abstract [en]

    Traffic management and traffic information are essential in urban areas and require reliable knowledge about the current and future traffic state. Parametric and nonparametric traffic state prediction techniques have previously been developed with different advantages and shortcomings. While nonparametric prediction has shown good results for predicting the traffic state during recurrent traffic conditions, parametric traffic state prediction can be used during nonrecurring traffic conditions, such as incidents and events. Hybrid approaches have previously been proposed; these approaches combine the two prediction paradigms by using nonparametric methods for predicting boundary conditions used in a parametric method. In this paper, parametric and nonparametric traffic state prediction techniques are instead combined through assimilation in an ensemble Kalman filter. For nonparametric prediction, a neural network method is adopted; the parametric prediction is carried out with a cell transmission model with velocity as state. The results show that the hybrid approach can improve travel time prediction of journeys planned to commence 15 to 30 min into the future, with a prediction horizon of up to 50 min ahead in time to allow the journey to be completed

  • 24.
    Allström, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Evaluation of travel time estimation based on LWR-v and CTM-v: A case study in Stockholm2012In: 15th International IEEE Conference on Intelligent Transportation Systems (ITSC), 2012, Piscataway, N.J, USA: IEEE , 2012, 1644-1649 p.Conference paper (Refereed)
    Abstract [en]

    Real-time estimations of current and future traffic states are an essential part of traffic management and traffic information systems. Within the Mobile Millennium project considerable effort has been invested in the research and development of a real-time estimation system that can fuse several sources of data collected in California. During the past year this system has been adapted to also handle traffic data collected in Stockholm. This paper provides an overview of the model used for highways and presents results from an initial evaluation of the system. As part of the evaluation process, GPS data collected in an earlier field-test and estimations generated by the existing system used by the TMC in Stockholm, are compared with the estimations generated by the Mobile Millennium system. Given that the Mobile Millennium Stockholm system has not undergone any calibration, the results from the evaluation are considered promising. The estimated travel times correspond well to those measured in the field test. Furthermore, the estimations generated by the Mobile Millennium system can be regarded as superior to those of existing traffic management system in Stockholm. The highway model was found to perform well even with a reduction in the number of sensors providing data. The findings of this study indicate the robustness of the Mobile Millennium system and demonstrate how the system can be migrated to other geographical areas with similar sources of available data.

  • 25.
    Alm, Johanna
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Plantin Vantell, My
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Problems and potential improvements of the order- and delivery process at Region Östergötland2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Region Östergötland (RÖ) har många olika order- och leveransprocesser varav en kallas för den yttre order- och leveransprocessen. Denna process är det informations- och materialflöde där beställning går direkt till leverantör och inte via den centraldepå som finns. Det är många personer som är inblandade och som ansvarar för olika delar av den yttre order- och leveransprocessen, samtidigt som personerna i fråga även arbetar på olika avdelningar. Detta tillsammans med att delar av processen sköts av en extern aktör har lett till att ingen ansvarar för hela processen i sig, och således finns inte heller en sammanhållen bild över processen. Syftet med rapporten är att ge en sammanhållen bild av den yttre order- och leveransprocessen samt belysa eventuella problem och ge förslag på förändringar som kan förbättra processen.

  • 26.
    Altkvist, Therese
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Hultman, Hanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Godsspårningssystem för landstinget i Östergötland2014Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Landstinget i Östergötland efterfrågar en högre spårbarhet för läkemedel och övrigt gods. Idag används godsspårningssystemet Arrival, levererat av Pitney Bowes för godsmottagningarna på Universitetssjukhuset i Linköping, Vrinnevisjukhuset i Norrköping samt på Lasarettet i Motala. För att kunna rekommendera vad Landstinget i Östergötland bör tänka på vid upphandling av ett eventuellt nytt godsspårningssystem har deras nuvarande system utvärderats och en omvärldsbevakning av alternativa spårningssystem har genomförts. Studien av Arrival baserades på fältstudier som genomfördes på godsmottagningar på Universitetssjukhuset i Linköping och Lasarettet i Motala samt genom intervjuer med användare och en kunnig brukare av systemet. Denna utvärdering av systemet resulterade i att ett antal förbättringsområden identifierades. I omvärldsbevakningen undersöktes tre alternativa godsspårningssystem från tre olika leverantörer. Ett nyutvecklat godsspårningssystem av ISS, TrueMobile Track and Trace av Optidev samt SendSuite av Pitney Bowes. Resultatet av detta examensarbete är ett antal rekommendationer till Landstinget i Östergötland avseende spårning av gods. Landstinget bör inkludera åsikter från systemanvändare vid upphandling samt erbjuda dem en fullgod utbildning i det initierande stadiet av en eventuell implementering av ett nytt godsspårningssystem. Landstinget bör vidare efterfråga funktioner som avläsningsverktyg som kan synkronisera trådlöst och en funktion för en mer tidseffektiv leverans av flera paket samt se över möjligheterna med RFID.

  • 27.
    Andersson, Anja
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Logistic process models for Swedtrac2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Detta examensarbete har utförts hos Swedtrac Trafik AB som är ett dotterbolag till Swedtrac AB. Swedtrac Trafik AB har trafikutövartillstånd och erbjuder utbildningar inom alla trafiksäkerhetsrelaterade delar av järnvägsverksamheten. Företaget har också verksamhet som löser kundernas transportbehov. Swedtrac Trafik AB baserar sin verksamhetsutveckling på processer vilket innebär att en processorienterad verksamhetsstyrning behövs för att klara dagens allt intensivare konkurrens på en global marknad. Därför är en initial processmall nödvändig. Syftet med detta examensarbete är att kartlägga nuvarande processer och göra en processmall/ett flödesschema från kundbeställning till slutprodukt samt ge en klar bild över var i processerna det finns möjlighet till effektivisering. Detta arbete är en studie av företagets processer med utvald processkartläggningsmetod. I metoden ingår studiebesök, telefon- grupp- och personlig intervju. Resultatet från dessa sammanställningar ger en djupare insyn i den nuvarande processen. Vid processkart-läggningen utgår arbetet från två vinklar: den ena är en ”as-is” process (swim lane chart) som utifrån beskrivningar från avdelningarnas intervjuer har ritats upp ett flöde över nuläget. Den andra är en ”to-be” process där problem som hittas i nulägesflödet har getts förslag på åtgärder. Processkarläggningen bygger på en SS-modell(sjustegsmodell). Varje steg bidrar till processmallen och har sitt eget syfte, mål och ett centralt värde för processkartläggningen. Resultatet består av två processmallar samt förbättringsförslag för nuläget och för framtiden. Förbättringsförslagen baseras på en processanalys av ”as-is” och ”to-be” processen. Processmallarna konstrueras med hjälp av modelleringsspråket ”BPMN”. Genom att jämföra de två processerna kan problem och förbättringsmöjligheter identifieras. När onödiga aktiviteter eliminerats och icke värdeskapande aktiviteter ändrats till värdeskapande, leder det till en minskning av administrativa kostnader samt att processens förmåga och effektiviteter förbättras. Detta innebär att processen kommer att utvecklas till en mer värdeskapande process.

  • 28.
    Andersson, Emma
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    An Economic Evaluation of the Swedish Prioritisation Rule for Conflict Resolution in Train Traffic Management2014In: Procedia - Social and Behavioral Sciences: Transportation: Can we do more with less resources?, Elsevier, 2014, 634-644 p.Conference paper (Refereed)
    Abstract [en]

    An increase in train traffic is a politically welcomed trend, which on the other hand has led to too high capacity utilisation at times and a railway network sensitive to disturbances. Delays are easily spread, causing high cost. A mean of controlling the secondary delays is to use efficient operational prioritisation rules for trains in conflict. This paper presents an evaluation of the current Swedish prioritisation rule. For two frequent conflict situations the associated cost related to applying the rule is calculated. The result indicates a poor economic efficiency and show that significant savings can be achieved by changing strategy.

  • 29.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Improved Railway Timetable Robustness for Reduced Traffic Delays – a MILP approach2015In: 6th International Conference on Railway Operations Modelling and Analysis, Tokyo, Mars 23-26, 2015., 2015Conference paper (Refereed)
    Abstract [en]

    Maintaining high on-time performance and at the same time having high capacity utilization is a challenge for several railway traffic systems. The system becomes sensitive to disturbances and delays are easily propagating in the network. One way to handle this problem is to create more robust timetables; timetables that can absorb delays and prevent them from propagating. This paper presents an optimization approach to reduce the propagating of delays with a more efficient margin allocation in the timetable. A Mixed Integer Linear Programming (MILP) model is proposed in which the existing margin time is re-allocated to increase the robustness for an existing timetable. The model re-allocates both runtime margin time and headway margin time to increase the robustness at specific delay sensitive points in a timetable. We illustrate the model’s applicability for a real-world case where an initial, feasible timetable is modified to create new timetables with increased robustness. These new timetables are then evaluated and compared to the initial timetable. We evaluate how the MILP approach affects the initial timetable structure and its capability to handle disturbances by exposing the initial and the modified timetables to some minor initial disturbances of the range 1 up to 7 minutes. The results show that it is possible to reduce the delays by re-allocating margin time, for example, the total delay at end station decreases with 28 % in our real-world example.

  • 30.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Introducing a New Quantitative Measure of Railway Timetable Robustness Based on Critical Points2013In: 5th International Seminar on Railway Operations Modelling and Analysis - RailCopenhagen 2013, 2013Conference paper (Refereed)
    Abstract [en]

    The growing demand for railway capacity has led to high capacity consumption at times and a delay-sensitive network with insufficient robustness. The fundamental challenge is therefore to decide how to increase the robustness. To do so there is a need for accurate measures that return whether the timetable is robust or not and indicate where improvements should be made. Previously presented measures are useful when comparing different timetable candidates with respect to robustness, but less useful to decide where and how robustness should be inserted. In this paper, we focus on points where trains enter a line, or where trains are being overtaken, since we have observed that these points are critical for the robustness. The concept of critical points can be used in the practical timetabling process to identify weaknesses in a timetable and to provide suggestions for improvements. In order to quantitatively assess how crucial a critical point may be, we have defined the measure RCP (Robustness in Critical Points). A high RCP value is preferred, and it reflects a situation at which train dispatchers will have higher prospects of handling a conflict effectively. The number of critical points, the location pattern and the RCP values constitute an absolute value for the robustness of a certain train slot, as well as of a complete timetable. The concept of critical points and RCP can be seen as a contribution to the already defined robustness measures which combined can be used as guidelines for timetable constructors.

  • 31.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Robustness in Swedish Railway Traffic Timetables2011In: Railrome 2011: Book of Abstracts 4th International Seminar on Railway Operations Modelling and Analysis / [ed] S. Ricci, I.A. Hansen, G. Longo, D. Pacciarelli, J. Rodriguez, E. Wendler, 2011Conference paper (Other academic)
    Abstract [en]

    A tendency seen for quite some time in the Swedish railway network is a growing demand for capacity which no longer can be accommodated. This causes congestion and delays, and the relationships between the trains and how they affect eachother are significantly harder to overview and analyse. Railway traffic timetables normally contain margins to make them robust, and enable trains to recover from certain delays. How effective these margins are, depends on their size and location as well as the frequency and magnitude of the disturbances that occur. Hence, it is important to include marigns so, that they can be used operationally to recover from a variety of disturbances and not restricted to a specific part of the line and/or the timetable. In a case study we compare the performance of a selection of passenger train services to the different prerequisites given by the timetable (e.g. available margins and their location, critical train dependencies). The study focuses on the Swedish Southern mainline between Stockholm and Malmö on which a wide variety of train services operate, e.g. freight trains, local and regional commuter train services as well as long-distance trains with different speed profiles. The analysis shows a clear mismatch between where margins are placed and where delays occur. We also believe that the most widely used performance measure, which is related to the delay when arriving at the final destination, might give rise to an unnecessarily high delay rate at intermediate stations.

  • 32.
    Andersson, Emma V.
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Blekinge Institute of Technology, Department of Computer Science and Engineering, Karlskrona, Sweden .
    Quantifying railway timetable robustness in critical points2013In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 3, no 3, 95-110 p.Article in journal (Refereed)
    Abstract [en]

    Several European railway traffic networks experience high capacity consumption during large parts of the day resulting in delay-sensitive traffic system with insufficient robustness. One fundamental challenge is therefore to assess the robustness and find strategies to decrease the sensitivity to disruptions. Accurate robustness measures are needed to determine if a timetable is sufficiently robust and suggest where improvements should be made.

    Existing robustness measures are useful when comparing different timetables with respect to robustness. They are, however, not as useful for suggesting precisely where and how robustness should be increased. In this paper, we propose a new robustness measure that incorporates the concept of critical points. This concept can be used in the practical timetabling process to find weaknesses in a timetable and to provide suggestions for improvements. In order to quantitatively assess how crucial a critical point may be, we have defined the measure Robustness in Critical Points (RCP). In this paper, we present results from an experimental study where a benchmark of several measures as well as RCP has been done. The results demonstrate the relevance of the concept of critical points and RCP, and how it contributes to the set of already defined robustness measures.

  • 33.
    Andersson, Erica
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Håkansson, Emelie
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Development of a decision support tool for evaluation of road assistance vehicle locations2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Förväntningarna på en väl fungerande trafiksituation med få stopp på vägarna är idag höga i Sverige. Befolkningsmängden i Stockholm ökar ständigt vilket innebär en ökad reseefterfrågan som bidrar till ett högt belastat vägnät. Vägar i storstadsmiljö med hårt belastad trafik är känsliga för minsta störning eftersom det kan innebära en stor påverkan på hela nätverket och på så sätt beröra ett stort antal trafikanter. För att minimera störningar i vägnätet bedriver Trafik Stockholm som en del av deras arbete verksamheten VägAssistans. VägAssistans är ett användbart verktyg för att snabbt lösa störningar i vägnätet och behålla en god trafikmiljö på vägarna. Ur ett samhällsekonomiskt perspektiv är det viktigt att VägAssistansfordonen placeras så att fordonet är snabbt på plats vid en händelse för att minimera störningar i nätverket. För detta krävs korta inställelsetider till områden där hög frekvens av händelser förekommer. Dessutom är det även viktigt att fordonen placera så att samtliga vägar i nätverket kan nås inom en rimlig körtid. Syftet med detta examensarbete är att utveckla ett beslutstödsverktyg för utvärdering av VägAssistansfordonsplaceringar. Syftet innefattar även att för beslutstödsverktyget utveckla en efterfrågemodell för prognostisering av framtida händelser, en körtidsmodell för att generera körtider i nätverket samt att ta fram intressanta effektivitetsmått för utvärdering och jämförelse av olika fordonplaceringar. Beslutstödsverktyget som utvecklas i detta projekt anses vara till stor nytta för Trafik Stockholm vid utvärdering av Vägassistansfordonsplaceringar i Stockholm. Dessa utvärderingar kan användas som stöd för att strategiskt placera VägAssistansfordonen så att händelser servas snabbt för att minimera störningen i nätverket som händelsen ger upphov till. En snabbare servad händelse innebär att antalet berörda trafikanter minimeras vilket leder till en minskad samhällskostnad.

  • 34.
    Andersson, Erik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Brandin, Emma
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Mapping of administrative tasks performed by medical doctors at the Department of Dermatology, University Hospital at Linköping2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Efter att en privat hudklinik i Linköping successivt lade ner sin verksamhet under år 2014, står Hudkliniken vid Universitetssjukhuset i Linköping inför en stor utmaning med ett ökat remissinflöde och en kontinuerligt ökad efterfrågan på vård. Under år 2014 tog Hudkliniken emot 1 300 fler remisser än år 2013 och i dagsläget har kliniken en patientkö på 2 000 patienter, vilken förväntas öka med 500-1 000 patienter de kommande åren. En heltidsarbetande läkare har i dagsläget totalt åtta timmars administrativ tid per vecka. Tidigare har kapacitetsberäkningar utförts på Hudkliniken, dock har aldrig de administrativa momenten läkarna utför studerats. Denna studie syftar till att kartlägga nuläget över vilka administrativa moment läkarna utför och sedan identifiera åtgärder som kan förbättra läkarens arbetsgång. Data har samlats in via en: fokusgruppsintervju, fyra semi-strukturerade intervjuer samt observationer av sex olika läkare. I den kartläggning som upprättats har totalt 89 stycken administrativa moment uppmärksammats dessutom har 3 icke administrativa moment identifierats, i samband med de olika datainsamlingarna. Det har observerats att det under ett typiskt administrationspass allokeras mycket tid till att läsa och bedöma laboratoriesvar utifrån respektive patientjournal. Det resultat som framkommit är att läkarna i dagsläget har för lite administrativ tid i förhållande till omfattningen på patientadministrationen; till viss del arbetar läkarna övertid för att hinna med. Ett av de moment som läkarna upplever stör arbetsgången är att spara diktat. Genom att införa funktionen att diktatets filnamn automatiskt döps till patientens personnummer skulle detta störningsmoment elimineras. I dagsläget har inte alla läkare en telefon vid sin arbetsplats, vilket kan skapa problem om två läkare vill ringa samtidigt eller om en av läkarna väntar på ett samtal samtidigt som den andre redan använder telefonen. Studien anser att införandet av dubbla skärmar kan effektivisera läkarnas administrativa arbete, då de ofta växlar mellan olika programvaror. Dessutom påpekar läkarna att det finns brister i de programvaror som de använder dagligen. För att åtgärda dessa brister bör Hudkliniken utse en ansvarig läkare som driver förbättringsarbetet för de berörda programvarorna.Slutligen rekommenderas Hudkliniken att utöka kommunikationen mellan de olika yrkeskategorierna samt införa olika tillfällen där läkarna kan framföra förbättringsförslag samt diskutera den dagliga verksamheten.

  • 35.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Axelsson, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Petersson, Jonas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Tatiana
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Configuration and Planning of the Remote TowerModules in a Remote Tower Center2016Conference paper (Refereed)
    Abstract [en]

    Today, many small aerodromes struggle withfinancial difficulties, and a large cost is air traffic control.Remote tower centers, which remotely provide air traffic servicesto aerodromes, can help reduce this cost. Each center maycontain a number of remote tower modules, where each moduleis manned by a controller that can handle one or moreaerodromes. In this paper we present the remote tower centerconcept and develop a model that optimizes the assignment ofairports to the remote tower modules. Computational results fora possible scenario based on real data for Swedish airports arepresented.

  • 36.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. CARER.
    Granlund, Rego
    SICS East Swedish ICT AB, Sweden.
    Lindborg, Jonas
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Ulander, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. CARER.
    Dynamisk planering av räddningstjänst2014Report (Other academic)
    Abstract [sv]

    Dynamisk planering innebär bland annat att brandmännen delar in sig i mindre grupper än traditionellt. Dessa kan då arbeta förebyggande med utbildning eller placeras strategiskt till exempel i närheten av olycksdrabbade vägsträckor, för att snabbare kunna nå fram till en olycksplats. Då en olycka inträffar larmas de brandmän som snabbast kan nå fram, och det kan vara nödvändigt att larma flera olika grupper.

    En utmaning vid dynamisk planering är att planeringssituationen blir svårare. Det är inte längre självklart vilka brandmän som ska larmas till en viss olycka. Det kan också vara svårt att hitta de bästa placeringarna för brandmän som snabbt ska kunna göra en insats.

    I projektet har vi utvecklat och utvärderat datorbaserade verktyg som kan stödja dynamisk planering av räddningstjänst.

    Bland verktygen finns en beredskapskalkylator med tillhörande visualisering, vilken beräknar beredskapen som en funktion av tiden det tar för de nödvändiga resurserna att nå fram till en viss typ av olycka och sannolikheten för att olyckan ska inträffa i närområdet. Ett annat verktyg kan ge förslag på vilka resurser som bör skickas till en olycksplats för att de ska komma fram så fort som möjligt. Ett tredje verktyg kan ge förslag på hur fordon och personal dynamiskt bör placeras för att beredskapen ska förbättras, dvs. de ska kunna nå fram så fort som möjligt till de platser där det är störst sannolikhet att en olycka kommer att inträffa.

    Verktygen har utvärderats genom två experimentserier. I experimenten testades mänskligt beslutsfattande i en simulerad räddningstjänstmiljö. I den första serien fick personal från olika räddningstjänster prova på dynamisk planering utan hjälp av de datorbaserade verktygen. I den andra serien fick andra räddningstjänster köra samma scenarier, men då ta hjälp av de i projektet utvecklade verktygen.

    Resultaten visar att verktygen kan hjälpa räddningstjänsten med planeringen av beredskapen, men också att det finns risk att detta sker på bekostnad av att planeringen tar något längre tid. En tydlig majoritet av de deltagande räddningstjänstbefälen var positivt inställda till de utvecklade verktygen och tyckte verktyg av detta slag skulle kunna hjälpa dem i det dagliga arbetet.

    Resultaten tydliggör också att olika personer – till och med nära kollegor inom samma räddningstjänst – uppfattar begreppet beredskap på olika sätt. Det visade sig dock att beredskapsvisualiseringen kan bidra till att denna skillnad i uppfattning minskar; i den andra experimentserien, där de hade tillgång till detta verktyg, minskade variationerna i bedömningarna och deltagarnas uppfattningar stämde bättre överens med den beräknade beredskapen.

  • 37.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Lundberg, Jonas
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering. CARER.
    Ulander, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rego, Granlund
    SICS Swedish ICT, Linkoping, Sweden.
    Supporting dispatch decisions for the fire and rescue services2015In: 2015 IEEE 18th International Conference on Intelligent Transportation Systems, IEEE conference proceedings, 2015, 2562-2567 p.Conference paper (Refereed)
    Abstract [en]

    Decision support tools for efficient dispatching of fire and rescue resources are developed and evaluated. The tools can give suggestions about which resources to dispatch to new accidents, and help the decision makers in evaluating the current preparedness for handling future accidents. The tools are evaluated using simulation game based experiments, with players from the fire and rescue services. The results indicate that the tools can help the fire and rescue services in identifying the closest resources to new accidents, and to select resources that preserve the preparedness in the area. However, the results also indicate that there is a risk that the tools increase the decision time. 

  • 38.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Tatiana
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A Novel MIP-based Airspace Sectorization for TMAs2017Conference paper (Refereed)
  • 39.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Tatiana
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Automatic Design of Aircraft Arrival Routes with Limited Turning Angle2016In: 16th Workshop on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2016) / [ed] Marc Goerigk and Renato Werneck, Dagstuhl, Germany, 2016, Vol. 54, 9:1-9:13 p.Conference paper (Refereed)
    Abstract [en]

    We present an application of Integer Programming to the design of arrival routes for aircraft in a Terminal Maneuvering Area (TMA). We generate operationally feasible merge trees of curvature-constrained routes, using two optimization criteria: (1) total length of the tree, and (2) distance flown along the tree paths. The output routes guarantee that the overall traffic pattern in the TMA can be monitored by air traffic controllers; in particular, we keep merge points for arriving aircraft well separated, and we exclude conflicts between arriving and departing aircraft. We demonstrate the feasibility of our method by experimenting with arrival routes for a runway at Arlanda airport in the Stockholm TMA. Our approach can easily be extended in several ways, e.g., to ensure that the routes avoid no-fly zones.

  • 40.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Tatiana
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Convex Sectorization--a Novel Integer Programming Approach2017In: Integrated Communications, Navigation and Surveillance Conference (ICNS), 2017, 2017Conference paper (Other academic)
    Abstract [en]

    The powerpoint presentation is about review of sectorization method that balances sector task load through extension by convex sectors, the results for Stockholm TMA. Also provides the comparison to convex sectorizations obtained by enumerating all possible topoligies for the given #sectors with highly flexible approach and fine-grained view on the TMA.

  • 41.
    Andersson, Martin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Jonasson, Gustav
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Utformning av en modell för lagerstyrning hos Atlas Copco GIA baserat på artikelklassificering2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Atlas Copco GIA tillverkar tunga maskiner och ventilationsutrustning till gruvindustrin. Branschen präglas av stor osäkerhet gällande efterfrågan och produktionen sker i relativt liten skala till följd av industrins begränsningar. För att behålla sin konkurrenskraft på marknaden erbjuder GIA möjlighet till stor kundspecifikhet i sitt produktutbud, och kunden får därmed stor valmöjlighet att modifiera de maskiner som beställs. Lågskalig produktion, varierad efterfrågan och hög kundspecifikhet gör det svårt för GIA att styra sitt lager och har därmed lett till hög kapitalbindning. Till följd av GIAs situation har examensarbetet genomförts och syftar till att föreslå en differentierad lagerstyrningsmodell för att möjliggöra en effektivare styrning av GIAs lager. Styrningsmodellen är därmed tänkt att minska kapitalbindningen samtidigt som lagertillgängligheten ej får påverkas negativt. Ett första steg vid konstruktion av föreslagen lagerstyrningsmodell har varit att genomföra en ABC-klassificering för det artikelsortiment som ingår i studien. Klassificeringen har möjliggjort en kategorisering av artiklarna baserat på dess ledtid och volymvärde. Ytterligare analys har genomförts för att mynna ut i fyra artikelgrupperingar som ligger till grund för lagerstyrningsmodellen. Modellen har konstruerats via analys av de lagerstyrningsprinciper som den teoretiska referensramen beskriver, men även baserat på genomförda intervjuer med inköpspersonalen på GIA för att få med många olika aspekter. Simuleringar har genomförts för att testa modellens agerande och dessa indikerar på att kapitalbindningen sjunker samt att fokus skiftar och läggs på volymvärda produkter, vilket är önskvärt. Även lagertillgängligheten antas bibehållas eller öka på grund av föreslagen lagerstyrningsmodell.

  • 42.
    Andersson, Peter
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Ivehammar, Pernilla
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Cost benefit analysis of dynamic route planning at sea2016In: TRANSPORT RESEARCH ARENA TRA2016, ELSEVIER SCIENCE BV , 2016, Vol. 14, 193-202 p.Conference paper (Refereed)
    Abstract [en]

    Route optimization through dynamic route planning, where ships can shorten their routes taking other vessels movements into account through shared information, has a potential to make transportation at sea more efficient. Fuel and emissions can be saved through green steaming without increased cargo transit times, and without reducing safety. This study estimates the potential net benefits to society in major areas in the Baltic Sea and the North Sea. It is found plausible that routes can be shortened by one percent on average, which would reduce costs to society by 80 million euros per year, of which 35 percent are reduced fuel costs and 65 percent are reduced emission costs. Alternative unit values of emissions give an interval of 55 to 113 million euros in benefits. The projects costs are estimated at 15 million euros per year. With a growing world trade, the potential for more efficient and environmentally friendly sea transportation through dynamic route planning may be substantial. (C) 2016 The Authors. Published by Elsevier B.V.

  • 43.
    Andersson, Peter
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Ivehammar, Pernilla
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Green approaches at sea - The benefits of adjusting speed instead of anchoring2017In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 51, 240-249 p.Article in journal (Refereed)
    Abstract [en]

    In this paper, the concept green approaches already used in aviation is applied to cargo transportation at sea. Instead of anchoring outside a port waiting for berth, ships can adjust their speed to arrive just in time for berthing. With improved incentives for reducing speed and shared information about berthing times, green approaches instead of anchoring can be a way to reduce fuel consumption and emissions without increasing the transit times of goods. The present study estimates the benefits to society as a whole for the EU ports in the Baltic Sea with Automatic Identification System data applying a new method using data collected in real time. Data consists of all anchored ships awaiting berth on 40 different occasions in 2015 and are subsequently extrapolated to a year. Fuel consumption by the individual ships, emissions and values are calculated from the detailed data with established models and estimates of unit values. The potential benefits are estimated at 27 million euros per year in the scenario where the near 15,000 anchorings by ships annually awaiting berth may instead start a green approach 12 h prior to arrival and may reduce speed by 25%, using the middle unit values for fuel and emissions. The methodology used in the paper can be applied to estimate the benefits of green approaches in other areas with anchored vessels. (C) 2017 Elsevier Ltd. All rights reserved.

  • 44.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Gundlegård, David
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rajna, Botond
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Vrotsou, Katerina
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Carlsson, Richard
    Ericsson Research, Services & Software.
    Forgeat, Julien
    Ericsson Research, Services & Software.
    Hu, Tracy H
    Ericsson Research, Services & Software.
    Liu, Evan L
    Ericsson Research, Services & Software.
    Moritz, Simon
    Ericsson Research, Services & Software.
    Zhao, Sky
    Ericsson Research, Services & Software.
    Zheng, Yaotian
    Ericsson Research, Services & Software.
    Mobility modeling for transport efficiency: Analysis of travel characteristics based on mobile phone data2013In: Netmob 2013: Mobile phone data for development / [ed] Vincent Blondel, 2013Conference paper (Refereed)
    Abstract [en]

    Signaling data from the cellular networks can provide a means of analyzing the efficiency of a deployed transportation system and assisting in the formulation of transport models to predict its future use. An approach based on this type of data can be especially appealing for transportation systems that need massive expansions, since it has the added benefit that no specialized equipment or installations are required, hence it can be very cost efficient.

    Within this context in this paper we describe how such obtained data can be processed and used in order to act as enablers for traditional transportation analysis models. We outline a layered, modular architectural framework that encompasses the entire process and present results from initial analysis of mobile phone call data in the context of mobility, transport and transport infrastructure. We finally introduce the Mobility Analytics Platform, developed by Ericsson Research, tailored for mobility analysis, and discuss techniques for analyzing transport supply and demand, and give indication on how cell phone use data can be used directly to analyze the status and use of the current transport infrastructure.

  • 45.
    Antonsson, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Ek, Johanna
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Transportkostnader i HKScans distribution: En utredning av vilka faktorer som driver transportkostnader och hur de kan påverkas2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report contains a case study of the company HKScan and focuses on their internal handling of transports to customers. As HKScan operates in a competitive industry with small margins, it is important that all money is used in the best way. An activity that costs money but rarely is investigated is the transportation since it is seen as a very operative activity. It has, however, been found that although different functions of a company are traditionally controlled separately, there are strong links between transports and functions such as sales, marketing, purchasing, finance, human resource management and production. The purpose of this study was therefore to investigate which factors that affect transport costs and provide suggestions on how transport costs can be reduced.

    The study of which factors that affect transport costs was carried out in several stages. First, factors mentioned in the theory were compiled and complemented by the factors that the Supply Chain department at HKScan believed could affect the cost. This resulted in a list of 18 possible influencing factors that were then demarcated depending on what HKScan measures and which was considered relevant to investigate. This demarcated list consisted of seven factors, which were then investigated using a multiple regression analysis. From this analysis, it could be mathematically proven that the parameters quantity, distance, weight per transport package, temperature, and the type of customer to which the transport went, affects the transport cost both at the shipping level and per transport package.

    After these drivers had been identified, interviews were held to investigate which departments have the greatest potential to influence them and, in the long run, affect transport costs. These interviews showed that it was primarily the sales and Supply Chain departments that affect the shipping costs, even though market and production have a more indirect impact.

    Finally, interviews were conducted with staff from the relevant departments to investigate how awareness and management of transport costs can be improved. This resulted in a large number of proposals where the most frequent one mentioned was a continuous follow-up on transport costs. This follow-up should point out which patterns in orders and shipments that gave rise to the higher cost. If this follow-up is to be done manually or by means of an automated tool, there are different views, but the staff feels that in order to reduce transport costs, they need increased awareness of what affects them.

  • 46.
    Araya, Yeheyies
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Detecting Swiching Points and Mode of Transport from GPS Tracks2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years, various researches are under progress to enhance the quality of the travel survey. These researches were mainly performed with the aid of GPS technology. Initially the researches were mainly focused on the vehicle travel mode due to the availability of GPS technology in vehicle. But, nowadays due to the accessible of GPS devices for personal uses, researchers have diverted their focus on personal mobility in all travel modes.

    This master’s thesis aimed at developing a mechanism to extract one type of travel survey information particularly travel mode from collected GPS dataset. The available GPS dataset is collected for travel modes of walk, bike, car, and public transport travel modes such as bus, train and subway.

    The developed procedure consists of two stages where the first is the dividing the track trips into trips and further the trips into segments by means of a segmentation process. The segmentation process is based on an assumption that a traveler switches from one transportation mode to the other. Thus, the trips are divided into walking and non walking segments.

    The second phase comprises a procedure to develop a classification model to infer the separated segments with travel modes of walk, bike, bus, car, train and subway. In order to develop the classification model, a supervised classification method has been used where decision tree algorithm is adopted.

    The highest obtained prediction accuracy of the classification system is walk travel mode with 75.86%. In addition, the travel modes of bike and bus have shown the lowest prediction accuracy. Moreover, the developed system has showed remarkable results that could be used as baseline for further similar researches.

  • 47.
    Ardic, Andreas
    et al.
    Linköping University, Department of Management and Engineering, Logistics Management. Linköping University, The Institute of Technology.
    Tingström, My
    Linköping University, Department of Management and Engineering, Logistics Management. Linköping University, The Institute of Technology.
    Förändring i färdigvarulager och utlastningen av foder efter införande av en ny produktmix: En fallstudie på Lantmännen Agroetanol2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master thesis was written for Lantmännen Agroetanol in Norrköping concerning the layout of their finished goods inventory and unloading of feed after introducing a new product mix. Lantmännen Agroetanol has two production lines which produces feed. Both lines lead to six silos, used as inventory of finished goods. The feed from the two production lines differ in terms of quality, where as Lantmännen Agroetanol wants to separate their finished inventory in order to charge a higher price, by selling the better product as a premium. With two different feed products the yearly revenue is expected to increase which motivates a research about the current capabilities and necessary changes to be made in the factory. This study aims to address part of this research by focusing on the breakdown of the finished inventory and the capabilities of the unloading function to this new product mix from a logistical perspective.

    In the study the inventory of finished goods were analyzed according to three different scenarios. Furthermore the unloading function was investigated with regards to two alternatives. Between the two production lines, Agro12 is the one that produces lowest quality and Agro10 the higher. The premium product is a result from the Agro10 production line, which today counts for a third of the Agro12 production volume. Even though great variation in market demands has been discovered for this product over the years, the demand for the premium product is expected to be higher due to its broad scope of use.

    The inventory of finished goods was analyzed using a simulation model programmed in Microsoft Excel. It was created based on information collected from interviews at the company as well as from their production system. Data of inventory levels, in- and outflow on a daily basis were collected over the year of 2012 in order to simulate the inventory capacity of the different inventory scenarios. The unloading function was analyzed by performing manual calculations, also with help from the employees and collected information from the production system. Data regarding in- and outflow and adjustment times were collected in order to calculate employee overtime as a result of the unloading function, which is controlled by employees.

    To be able to compare the three inventory scenarios and the two unloading alternatives with each other a total cost model was used along with a service flexibility view as a complement. In the cost model, the Investment costs were calculated for possible rebuilding’s that has to be made. The variable costs related to the inventory were calculated based on handling costs of the excess of feed from the simulations. The corresponding variable costs for the unloading function were calculated based on overtime hours for the employees. Qualitatively, the flexibility for the customer was analyzed with regards to changes in the unloading function.

    The results according to this study show that Lantmännen Agroetanol should implement inventory scenario 3 which means that the feed from Agro10 will be stored in two silos and the feed from Agro12 in three silos. The remaining silo will be used as a stand-by ready to store the product that needs extra capacity the most. Scenario 1 means that the production lines gets three silos each, which turned up to be an in appropriate solution according to the simulations because Agro10 only required a third silo in 16 out of 366 days. Scenario 2 is more appropriate because Agro12 has a bigger need for a fourth silo.Scenario 2 and 3 has the same need of rebuilding whereas the stand-by silo can be reached from both production lines. Scenario 3 is recommended because it entails the possibility to regulate the stand-by silo which makes it less sensitive for disturbances compared to scenario 2.

    The study also recommends Lantmännen Agroetanol to build a new unloading silo instead of just using the current one so that the two feed products could be unloaded simultaneously. It is a big investment cost to build a new unloading silo but the results from this study show that it is more profitable than just having one in the long turn. With one unloading silo the employees have to work with adjustment times every time two subsequent customers want different feed products. It means that the employees have to adjust the unloading silo to the other product. There is already overtime among the unloading staff which means that one of the most strained functions in the company will be even more pressured with only one silo to unload two products. In addition, the boat transportations with high capacity that appear on a weekly basis affect the flexibility towards the customers. Thus, giving yet another reason for two silos rather than one, when introducing the new product mix.

  • 48.
    Aria, Erfan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Rd and Transport Research Institute VTI, Linkoping, Sweden.
    Schwietering, Christoph
    Schwietering Traff Engineers, Germany.
    Investigation of Automated Vehicle Effects on Drivers Behavior and Traffic Performance2016In: INTERNATIONAL SYMPOSIUM ON ENHANCING HIGHWAY PERFORMANCE (ISEHP), (7TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, 3RD INTERNATIONAL SYMPOSIUM ON FREEWAY AND TOLLWAY OPERATIONS), ELSEVIER SCIENCE BV , 2016, Vol. 15, 761-770 p.Conference paper (Refereed)
    Abstract [en]

    Advanced Driver Assistance Systems (ADAS) offer the possibility of helping drivers to fulfill their driving tasks. Automated vehicles (AV) are capable of communicating with surrounding vehicles (V2V) and infrastructure (V2I) in order to collect and provide essential information about the driving environment. Studies have proved that automated driving have the potential to decrease traffic congestion by reducing the time headway (THW), enhancing the traffic capacity and improving the safety margins in car following. Despite different encouraging factors, automated driving raise some concerns such as possible loss of situation awareness, overreliance on automation and system failure. This paper aims to investigate the effects of AV on drivers behavior and traffic performance. A literature review was conducted to examine the AV effects on drivers behavior. Findings from the literature survey reveal that conventional vehicles (CV), i.e. human driven, which are driving close to a platoon of AV with short THW, tend to reduce their THW and spend more time under their critical THW. Additionally, driving highly AV reduce situation awareness and can intensify driver drowsiness, exclusively in light traffic. In order to investigate the influences of AV on traffic performance, a simulation case study consisting of a 100% AV scenario and a 100% CV scenario was performed using microscopic traffic simulation. Outputs of this simulation study reveal that the positive effects of AV on roads are especially highlighted when the network is crowded (e.g. peak hours). This can definitely count as a constructive point for the future of road networks with higher demands. In details, average density of autobahn segment remarkably improved by 8.09% during p.m. peak hours in the AV scenario, while the average travel speed enhanced relatively by 8.48%. As a consequent, the average travel time improved by 9.00% in the AV scenario. The outcome of this study jointly with the previous driving simulator studies illustrates a successful practice of microscopic traffic simulation to investigate the effects of AV. However, further development of the microscopic traffic simulation models are required and further investigations of mixed traffic situation with AV and CV need to be conducted.

  • 49.
    Askerud, Caroline
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Wall, Sara
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Evaluation of bus terminals using microscopic traffic simulation2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Traffic simulation is a safe and efficient tool to investigate infrastructural changes as well as traffic conditions. This master thesis aims to analyse a microscopic traffic simulation method for evaluation of bus terminal capacity. The evaluation is performed by investigating a case study of the bus terminal at Norrköping travel centre. The analysed method, referred to as terminal logic in the thesis, uses a combination of time based and event based simulation. Through the combination of time and event, it is possible to capture all movements within the terminal for individual vehicles. The simulation model is built in the software Vissim. A new travel centre for Norrköping is under development. Among the reasons for a new travel centre is the railway project Ostlänken in the eastern part of Sweden. An evaluation of the bus terminal is interesting due to a suspicion of overcapacity and the opportunity of redesigning. To investigate both the terminal capacity and the terminal logic, three scenarios were implemented. Scenario 1: Current design and frequency Scenario 2: Current design with higher frequency Scenario 3: Decreased number of bus stops with current frequency The results from the scenarios confirm the assumption of overcapacity. The capacity was evaluated based on several different measures, all indicating a low utilization. Even so, the utilization was uneven over time and congestion could still occur when several buses departed at the same time. This was also seen when studying the simulation, which showed congestions when several buses departed at the same time. The case study established the terminal logic to be useful when evaluating capacity at bus terminals. It provides a good understanding of how the terminal operates and captures the movements. However, it was time-consuming to adjust the logic to the studied terminal. This is a disadvantage when investigating more than one alternative. The thesis resulted in two main conclusions. Firstly, a more optimised planning of the buses at Norrköping bus terminal would probably be achievable and lead to less congestions at the exits. Secondly, the terminal logic is a good method to use when evaluating bus terminals but it is not straight forward to implement.

  • 50.
    Axelsson, Eva
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Wilson, Therese
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Microscopic simulation as an evaluation tool for the road safety of vulnerable road users2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Traffic safety has traditionally been measured by analyzing historical accident data, which is a reactive method where a certain number of accidents must occur in order to identify the safety problem. An alternative safety assessment method is to use proximal safety indicators that are defined as measures of accident proximity, which is considered a proactive method. With this method it is possible to detect the safety problem before the accidents have happened. To be able to detect problems in traffic situations in general, microscopic simulation is commonly used. In these models it may be possible to generate representative near-accidents, measured by proximal safety indicator techniques. A benefit of this would be the possibility to experiment with different road designs and evaluate the traffic safety level before reconstructions of the road infrastructure. Therefore has an investigation been performed to test the possibility to identify near-accidents (conflicts) in a microscopic simulation model mimicking the Traffic Conflict Technique developed by Hydén (1987). In order to perform the investigation a case study has been used where an intersection in the city center of Stockholm was studied. The intersection has been rebuilt, which made it possible to perform a before and after study. For the previous design there was a traffic safety assessment available which was carried out using the Traffic Conflict Technique. Microscopic simulation models representing the different designs of the intersection were built in PTV Vissim. In order to evaluate and measure the traffic safety in reality as well as in the microscopic simulation models, a traffic safety assessment was performed in each case. The traffic safety assessment in field for the present design was carried out as a part of this thesis. The main focus of this thesis was the road safety for vulnerable road users. The method to identify conflicts in the simulation model has been to extract raw data output from the simulation model and thereafter process this data in a Matlab program, aiming to mimic the Traffic Conflict Technique. The same program and procedure was used for both the previous and the present design of the intersection. The results from the traffic safety assessment in the simulation model have been compared to the results from the field study in order to evaluate how well microscopic simulation works as an evaluation tool for traffic safety in new designs. The comparison shows that the two methods of conflict identification cannot replace each other straight off. But with awareness of the differences between the methods, the simulation model could be used as an indication when evaluating the level of traffic safety in a road design.

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