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  • 51.
    Andersson, Daniel
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Sandholm, Christian
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Total Cost Analysis of frame suppliers in construction2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gotec, som är ett bygg och förvaltningsföretag, är just nu inne på etapp ett av ett byggprojekt i Vallastaden, Linköping. För etapp ett slöt Gotec ett avtal med den polska stomleverantören Baumat, att de skulle leverera samtliga stommar till Gotecs byggnader i projektet. Valet av leverantör baserades till största del på det låga inköpspriset. Dock upplever Gotec idag att det har uppstått vissa problem med Baumat som leverantör. Ett problem som Gotec upplever är att kommunikationen inte har fungerat så bra som de hade hoppats på, detta då engelskan är ytterst bristfällig inom Baumat. Andra problem som märkts av under samarbetet är bland annat att flexibiliteten och leveransprecisionen inte har varit perfekt. Detta har lett till att leveransförseningar har uppstått som i sin tur har givit upphov till extra kostnader, så kallade ÄTOR. Denna fallstudie utreder vilken leverantör av stommar som skulle vara det bästa alternativet för Gotec att använda sig av vid ett byggprojekt i Vallastaden i framtiden. En leverantör från ett lågkostnadsland eller en leverantör från Sverige. De leverantörer som utreds är Gotecs nuvarande leverantör Baumat som representerar en leverantör från ett lågkostnadsland och Strängbetong som representerar en leverantör från Sverige.

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    Total Cost Analysis of frame suppliers in construction
  • 52.
    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, p. 634-644Conference 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.

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  • 53.
    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.

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  • 54.
    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.

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    RailCopenhagen
  • 55.
    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.

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  • 56.
    Andersson, Emma V.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Assessment of Robustness in Railway Traffic Timetables2014Licentiate thesis, monograph (Other academic)
    Abstract [en]

    A tendency seen for the last decades in many European railway networks is a growing demand for capacity. An increased number of operating trains has led to a delay sensitive system where it is hard to recover from delays, where even relatively small delays are easily propagating to other traffic.

    The overall aim of this thesis is to analyse the robustness of railway traffic timetables; why delays are propagating in the network and how the timetable design and dispatching strategies influence the delays. In this context we want to establish quantitative measures of timetable robustness. There is a need for measures that can be used by the timetable constructors. Measures that identify where and how to improve the robustness and thereby indicating how and where margin time should be inserted. It is also important that the measures can capture interdependencies between different trains.

    In this thesis we introduce the concept of critical points, which is a practical approach to identify robustness weaknesses in a timetable. In contrast to other measures, critical points can be used to identify specific locations in both time and space. The corresponding measure, Robustness in Critical Points (RCP) provides the timetable constructors with concrete suggestions for which trains that should be given more runtime or headway margin. The measure also identifies where the margin time should be allocated to achieve a higher robustness.

    In a case study we show that the delay propagation is highly related to the operational train dispatching. This study shows that the current prioritisation rule used in Sweden results in an economic inefficiency and therefore should be revised. This statement is further supported by RCP and the importance of giving the train dispatchers more flexibility to efficiently solve conflict situations.

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    Assessment of Robustness in Railway Traffic Timetables
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    omslag
  • 57.
    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, p. 95-110Article 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.

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  • 58.
    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.

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  • 59.
    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.

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  • 60.
    Andersson Granberg, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    How to very quickly solve a staffing and dispatching problem for fire and rescue services2010Conference paper (Other academic)
  • 61.
    Andersson Granberg, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Preparedness Measures for Emergency and Disaster Response2013In: Humanitarian and Relief Logistics: Research Issues, Case Studies and Future Trends / [ed] Vasileios Zeimpekis, Soumia Ichoua, Ioannis Minis, Springer-Verlag New York, 2013, p. 59-75Chapter in book (Refereed)
    Abstract [en]

    Quantitative preparedness measures can be used to calculate the level of preparedness for handling disasters or emergencies. They are useful for evaluating plans and preparations, and for comparing areas and organizations with each other. This chapter gives an introduction to the construction and use of such measures, and proposes a general methodology that can be applied when developing them. The methodology is exemplified on two case studies, the first concerning disaster preparedness, and the second daily events. In the first case study, a hurricane disaster risk index is developed to compare the preparedness for handling hurricanes in different counties. The second case study describes the development and validation of a preparedness measure for emergency medical services, which is used to support decisions about ambulance dispatch and relocation.

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  • 62.
    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.

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  • 63.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Danielsson, Niklas
    Linköping University, Center for Advanced Research in Emergency Response (CARER). Geotelix AB.
    Fredriksson, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Nordström, Johan
    Räddningstjänsten Östra Götaland.
    Pilemalm, Sofie
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    Tjernström, Richard
    Norrköping Municipality.
    Yousefi Mojir, Kayvan
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    Using Semi-professionals in Emergency Response2016In: Proceedings of the 13th International Conference on Information Systems for Crisis Response and Management / [ed] Andrea H. Tapia, Pedro Antunes, Victor A. Bañuls, Kathleen Moore and João Porto de Albuquerque, 2016, p. 1-6Conference paper (Other academic)
    Abstract [en]

    The term semi-professional can be used to denote occupational groups that do not have emergency response as their primary profession but who get additional responsibilities within rescue and response, e.g. by performing a first response or assisting the professional emergency services. In this study, four different groups of possible semi-professional resources are analyzed and compared. Similarities and differences between the four groups are discussed. Factors, important for the successful implementation of a cross-sector collaboration of this kind, are highlighted. The preliminary results show that all four groups have the potential to act as semi-professional resources within emergency response. Interestingly, the basic requirements are the same for all groups, despite different prerequisites.

  • 64.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Fredriksson, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Pilemalm, Sofie
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    Yousefi Mojir, Kayvan
    Linköping University, Department of Management and Engineering, Information Systems. Linköping University, Faculty of Arts and Sciences.
    Effektivt sambruk av kommunala resurser för ökad säkerhet och trygghet2017Report (Other academic)
    Abstract [sv]

    Användandet av så kallade semiprofessionella resurser i räddningsinsatser har blivit allt vanligare i Sverige. En semiprofessionell är en person som fått utökade arbetsuppgifter inom respons och räddning inom ramen för sitt ordinarie yrke. Det kanske mest kända exemplet är väktare som responderar på den kommunala räddningstjänstens ärenden.

    I det projekt som avrapporteras här, är syftet att undersöka vilka yrkesgrupper som skulle passa bra som semiprofessionella, och vad som krävs för att de effektivt ska kunna utföra de nya arbetsuppgifterna, bland annat i form av utbildning och utrustning. Vidare syftar projektet till att utvärdera vilken samhällsnytta semiprofessionella kan bidra med. Som studieobjekt används Norrköpings kommun, och via en aktionsforskningsinspirerad metodansats är målet att projektresultaten ska kunna bidra till en ökad säkerhet och trygghet i kommunen.

    En kombination av kvalitativa och kvantitativa metoder används för att uppnå syftet. Genom workshops identifieras först fyra potentiella yrkesgrupper (räddningstjänstens dagtidspersonal, hemtjänstpersonal, förvaltningsentreprenörer och väktare), för vilka detaljerad data erhålls via fokusgruppsintervjuer. En grupp (räddningstjänstens dagtidspersonal) väljs ut för vidare analys, och ytterligare en workshop genomförs, plus ett experiment i form av en simulerad olycka där semiprofessionella får göra en första insats. En prototyp av ett utlarmningssystem tas fram, inklusive en smartphoneapplikation som de semiprofessionella kan använda för att ta emot och hantera larm. Med hjälp av applikationen utförs ett experiment där historiska larm skickas till potentiella semiprofessionella under två månaders tid, och de får svara på om de kan åka eller inte, samtidigt som deras position noteras. Genom att jämföra deltagarnas uppskattade insatstider med räddningstjänstens historiska, kan möjliga insatstidsförkortningar beräknas. Detta kompletteras med en bedömning av vad de kan bidra med i respektive händelse.

    Bedömningen görs enligt en strukturerad metod av professionell personal från två olika räddningstjänstorganisationer. De beräknade insatstiderna och den skattade förmågan vägs samman till en monetär nytta av den semiprofessionella insatsen.

    Resultatet visar att det finns ett stort antal yrkesgrupper som skulle kunna vara lämpliga att nyttja som semiprofessionella. I rapporten redovisas en lista med 23 grupper som anses ha potential och möjlighet att utföra räddningsinsatser som en del av sitt yrke. Vidare redovisas ett antal utmaningar och möjligheter, baserat på analysen av de fyra utvalda grupperna. En konkret sammanställning har gjorts i form av listor på utbildning och utrustning som krävs för att de effektivt kunna utföra sitt nya uppdrag. Dessa krav är förhållandevis enkla att uppfylla, och handlar om grundläggande utbildning i riskbedömning, brandsläckning och livräddande åtgärder, samt utrustning som tex handbrandsläckare och förbandslåda. Mer utmanande är de organisatoriska förändringar som är nödvändiga för att de semiprofessionella akut ska kunna lämna sina pågående arbetsuppgifter, samt hur utlarmningen ska kunna integreras i de tekniska system som används för professionella räddningsresurser. Vidare visar resultaten att semiprofessionella kan larmas, och förväntas göra nytta på en stor mängd olika typer av händelser, dock främst vid händelser med personskador eller akuta sjukdomsförlopp. Den monetära nyttan av att införa ett fåtal (i snitt 3,4 st) semiprofessionella i Norrköping och Linköpings kommuner beräknades till mellan 600 000 och 2 400 000 kr per år, beroende på hur lång tid det tar för de semiprofessionella ifrån att de får larm tills de påbörjar färden mot händelseplatsen.

    En slutsats från projektet är att semiprofessionella skulle bidra till en ökad säkerhet och trygghet i Norrköping kommun, om de används som förstainsatsresurser, som ett komplement till befintlig professionell räddningspersonal.

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    Effektivt sambruk av kommunala resurser för ökad säkerhet och trygghet
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  • 65.
    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.

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  • 66.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Gustafsson, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Using variable neighborhood search to locate fire and rescue resources for Räddningstjänsten Östra Götaland2011Conference paper (Refereed)
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    Extended abstract
  • 67.
    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.
    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, p. 2562-2567Conference 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. 

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  • 68.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Munoz, Ander Oquillas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Developing key performance indicators for airports2013Conference paper (Refereed)
    Abstract [en]

    We develop a set of airport key performance indicators, i.e. a set of measures that can be used to monitor and manage an airport, giving indications of the current state of the operations and supporting improvement work. By reviewing previous relevant work, the airport is divided into five activity areas (operations, economy, environmental issues, safety and security, costumer service), and for each area an initial set of indicators is selected. These indicators are then ranked by airport managers in Sweden and Spain, using a questionnaire based survey. Using the ranking as a base, a final set of indicators is constructed with the aim that is should be manageable, easy to interpret and useful for analyzing the entire airport.

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  • 69.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Nguyen, Ngoc Hien Thi
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    SIMULATION BASED PREDICTION OF THE NEAR-FUTURE EMERGENCY MEDICAL SERVICES SYSTEM STATE2018In: 2018 WINTER SIMULATION CONFERENCE (WSC), IEEE , 2018, p. 2542-2553Conference paper (Refereed)
    Abstract [en]

    An ambulance dispatcher decides which ambulances to allocate to new calls, and how to relocate ambulances in order to maintain a good coverage. Doing this, it is valuable to have information about the future expected response times in different parts of the area of responsibility, as well as the expected number of available ambulances. We present a simulation model that can be used to predict this, and compare the results to a naive forecasting model. The results show that while it is difficult to accurately predict the future system state, the simulation based prediction manages this better than the naive model.

  • 70.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Norin, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Integrating optimization and simulation to gain more efficient airport logistics2009In: Eighth USA/Europe Air Traffic Management Research and Development Seminar (ATM2009), 2009, p. 1-10Conference paper (Refereed)
    Abstract [en]

    In this paper we present airport logistics, which is a framework of resource management in the air transportation system. Focus is on the processes supporting turn-around. A detailed simulation model of various processes involved in turn-around is developed, by which the interaction between these processes are analyzed. We show that integrating optimization and simulation is a powerful tool to demonstrate efficiency improvements in airport logistics, using scheduling de-icing trucks as an example. An optimization algorithm for scheduling de-icing trucks is developed and simulations are performed comparing different schedules. The schedule obtained when considering total airport performance in the optimization algorithm gives minimum flight delay and waiting times in the simulations.

  • 71.
    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 framework for integrated terminal airspace design2019In: Aeronautical Journal, ISSN 0001-9240, Vol. 123, no 1263, p. 567-585Article in journal (Refereed)
    Abstract [en]

    Route planning and airspace sectorisation are two central tasks in air traffic management. Traditionally, the routing and sectorisation problems were considered separately, with aircraft trajectories serving as input to the sectorisation problem and, reciprocally, sectors being part of the input to the path finding algorithms. In this paper we propose a simultaneous design of routes and sectors for a transition airspace. We compare two approaches for this integrated design: one based on mixed integer programming, and one Voronoi-based model that separates potential "hotspots" of controller activity resulting from the terminal routes. We apply our two approaches to the design of Stockholm Terminal Maneuvering Area.

  • 72.
    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 Framework for Integrated Terminal Airspace Design2017Conference paper (Refereed)
  • 73.
    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)
  • 74.
    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, p. 9:1-9:13Conference 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.

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    Automatic Design of Aircraft Arrival Routes with Limited Turning Angle
  • 75.
    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.
    Integer Programming-Based Airspace Sectorization for Terminal Maneuvering Areas with Convex Sectors2019In: Journal of Air Transportation, E-ISSN 2380-9450, Vol. 27, no 4Article in journal (Refereed)
    Abstract [en]

    In this paper an airspace sectorization framework for terminal maneuvering areas based on mixed integer programming is presented. It incorporates an airspace complexity representation, as well as various constraints on the sectors’ geometry, for example, the requirement that points demanding increased attention from air traffic controllers should lie in the sector’s interior to allow for enough time to resolve possible conflicts. The method can enforce convex sectors. In contrast to earlier integer/constraint programming approaches, which used synthesis methods with variables per elementary airspace piece that were glued together to form sectors, the integer programming formulation uses a variable per potential edge on the sector boundary. It is also the first step toward an integrated design of routes, the resulting complexity, and a sectorization. This paper presents results for Stockholm Arlanda airport and compares the integer programming results to convex sectorizations obtained by enumerating all possible topologies for a given number of sectors. This yields a proof-of-concept for the application of this highly flexible approach to terminal maneuvering areas.

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  • 76.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Socially optimal allocation of ATM resources via truthful market-based mechanisms2012In: Proceedings of the SESAR Innovation Days (2012) / [ed] Schaefer, Dirk, 2012Conference paper (Other academic)
  • 77.
    Andersson, Henrik
    et al.
    Norwegian Univ Sci and Technol, Norway.
    Andersson Granberg, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Christiansen, Marielle
    Norwegian Univ Sci and Technol, Norway.
    Skorge Aartun, Eirik
    Norwegian Univ Sci and Technol, Norway.
    Leknes, Hakon
    Norwegian Univ Sci and Technol, Norway.
    Using optimization to provide decision support for strategic emergency medical service planning - Three case studies2020In: International Journal of Medical Informatics, ISSN 1386-5056, E-ISSN 1872-8243, Vol. 133, article id UNSP 103975Article in journal (Refereed)
    Abstract [en]

    To achieve high performing emergency medical services (EMS), planning is of vital importance. EMS planners face several challenges when managing ambulance stations and the fleet of ambulances. In this paper, three strategic cases for EMS planners are presented together with potential solutions. In the first case, the effects of closing down a local emergency room (ER) are analyzed together with how adding an ambulance station and an ambulance to the area affected by the closing of the ER can be used to mitigate the negative consequences from the closing. The second case investigates a change in the organization of EMS. Currently, many non-urgent transport assignments are performed by ambulances which make them unavailable for more urgent calls. The potential for a more effective utilization of the ambulances is explored through transferring these assignments to designated transport vehicles. The third case is more technical and challenges the common practice regarding how time dependent demand is handled. Looking at the busiest hour or the average daily demand, is compared with taking time varying demand into account. The cases and solutions are studied using a recently developed strategic ambulance station location and ambulance allocation model for the Maximum Expected Performance Location Problem with Heterogeneous Regions (MEPLP-HR). The model has been extended to also include multiple time periods. This article demonstrates an innovative use of the model and how it can be applied to find and evaluate solutions to real cases within the field of strategic planning of EMS. The model is found to be a useful decision support tool when analyzing the cases and the expected performance of potential solutions.

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  • 78.
    Andersson, Markus
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Blomdahl, Rikard
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Adjusting route charges to increase profit2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Route charges are fees that airlines pay in order to utilize the Air Navigation Services (ANS) of a European state. The fee is based on three values; the weight of the aircraft, the length of the flight, and the state’s specific unit rate. The unit rate of each state is in turn based on the forecasted costs of providing ANS for that state and the amount of traffic forecasted for the year to come.

    This makes for different unit rates for different states, which leads to different costs for flying different routes in the European airspace. A state having costs that are increasing faster than the amount of traffic is increasing will lead to a higher unit rate. A higher unit rate may lead to airlines avoiding the state’s airspace due to higher costs, thus accounting for even less traffic and an increase in unit rate.

    This thesis examines the relationship between unit rate and amount of traffic, and specifically tries to find out how much the unit rate affects the traffic count. This has been done by reading previous papers on the subject, and creating a model to easily present facts found.

    The result of the thesis suggests that states actually profits more by increasing the unit rate rather than actively trying to reduce it. This contradicts the idea of lowering prices always being a good thing. There is a limit to how much the unit rate can be increases however, at which all traffic will choose to circumnavigate the airspace. Finding a good balance between traffic lost and unit rate increased is suggested as the best way to go.

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  • 79.
    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.

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  • 80.
    Andersson, Matilda
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Wandfelt, Fredrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Optimization of maintenance system2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report presents an optimization of the allocation of maintenance resources for Air Navigation Service (ANS) equipment of which LFV is responsible for the maintenance. The purpose the authors have worked after is to research ways of minimizing travelling time linked to maintenance visits for ANS equipment, this report includes the suggestions where the maintenance facilities should be placed in order to minimize the total travelling time. The report describes the problem background and presents the customer, LFV. It includes a chapter on some of the theories used for facility location and routing, and also presents methods for reducing the total travelling time used for maintenance visits annually. The authors have worked with a given set of airports in Sweden. Information about the general work with maintenance as well as the annual demand of maintenance, including the frequency of visits, for each airport included in this project was received by Pär Oberger, the task expert and contact at LFV for this report. A model for facility location based on the p-median model have been created and used when solving the problem, it was written in AMPL and solved with the CPLEX solver. The model was modified with two additional constraints regulating the minimum annual working time and the maximum distance for one-way travelling. The authors deems that a solution with five facilities is better since the benefit of additional facilities, in term of lower total distance, do not compensate for the assumed cost of establishing them.

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  • 81.
    Andersson, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    The flight perturbation problem: operational aircraft rescheduling2001Licentiate thesis, monograph (Other academic)
    Abstract [en]

    When there is a perturbation in a carefully planned flight schedule, e.g. an aircraft breakdown, it is important to minimize the negative consequences of this disturbance. In this thesis, a model and a number of solution strategies for the Flight Perturbation Problem is presented. Based on a connection network, a mixed integer multicommodity flow model with side constraints is developed. Cancellations, delays and aircraft swaps, both within the same fleet and between different aircraft types, are used to take care of the perturbation. The model also assures that the schedule returns to normal within a certain time.

    Six different solution strategies arc used to solve the model; the first based on a Lagrangian relaxation of the mixed integer multicommodity flow model. Four strategies are based on Dantzig-Wolfe decomposition and in two of them all feasible points are generated by a tree search algorithm before the master problem is solved, while the other two are column generation based. The last strategy is based on the metaheuristic tabu search.

    The computational tests with real problem data show that the Dantzig-Wolfe based strategies and the tabu search strategy arc very promising, and especially the tabu search strategies could be used in a real problem application that could provide airlines with solutions to complex perturbation problems.

  • 82.
    Andersson, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Petersson, Sverker
    SOS Alarm AB, Sweden.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Decision support for efficient ambulance logistics2007In: Operational Research for Health Policy: Making Better Decisions: Proceedings of the 31st Annual Conference of the European Working Group on Operational Research Applied to Health Services / [ed] Sally Brailsford, Paul Harper, Bern, Switzerland: Peter Lang AG , 2007, p. 107-125Conference paper (Refereed)
    Abstract [en]

    Ambulance logistics comprises everything that has to do with managing an efficient ambulance health care, which includes both emergency medical services and patient transportations. In this work, ambulance logistics is defined and discussed using the Swedish public service enterprise SOS Alarm as a basis. A number of ways of improving the ambulance logistic service provided by SOS Alarm are identified, and nine areas of improvement are defined. Two of the nine areas, -Visualisation of the preparedness- and -Decision support for efficient ambulance logistics- are described in more detail. In both of these, the main improvement lays in the development of decision support tools for the ambulance dispatchers. The tools that are developed are a preparedness calculator, an ambulance dispatch suggestion tool, a relocation tool and a simulation tool.

  • 83.
    Andersson, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Särdqvist, Stefan
    Swedish Rescue Services Agency, Sweden.
    Planning for effective use of fire and rescue service resources2007In: Interflam 2007 (Vol.2): 11th International Fire Science & Engineering Conference, London, UK: Interscience Communications, 2007, p. 1561-1566Conference paper (Other academic)
    Abstract [en]

    In this work, a model has been developed that can support and evaluate decisions on the location of rescue service resources. The main contributions are the possibilities to model multiple events and multiple resources, and foremost providing a method of quantifying the interaction between events and resources. In the model, it is possible to analyse different ways of organising the fire and rescue service, e.g. comparing the effect of small units in multiple locations with a traditional way of organising, where most resources comes from a single fire station. The model can also suggest advantageous locations for the resources.

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  • 84.
    Andréasson, Ros-Mari
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Att bygga och bo i ett flerbostadshus av KL-trä med Valla Berså som referensobjekt2018Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    I denna studie utreds KL-trä, korslimmat trä, ur byggnadsteknisk synvinkel samt ur ett boendeperspektiv, där Valla Berså som är Linköpings första flerbostadshus byggt med en stomme av KL-trä fick agera referensobjekt. Byggnationen av flerbostadshus i trä ökar i stadig takt. KL-trä är resultatet av den senaste utvecklingen inom massivträkonstruktioner. De industriellt framtagna skivorna i KL-trä kan tillverkas i stora format och dess höga bärförmåga och styvhet i förhållande till vikten möjliggör att bygga högre, större och stabilare än med traditionellt träregelvirke. Trä är det enda helt förnyelsebara byggmaterialet. Det tillverkas i en energisnål process med minimal miljöpåverkan och binder koldioxid under hela sin livslängd. Byggbranschen börjar inse att ett skifte från betong till trä är det enda rätta om de totala koldioxidutsläppen ska minska. Men det behövs mer kunskap kring att använda trä i flerbostadshus som har höga krav på brandsäkerhet och ljudmiljö. För att ta reda på vilka för- och nackdelar det finns att bygga med KL-trä, vilka lösningar som finns för att höja funktionen och säkerheten i ett KL-trähus och vilka effekter ett massivträhus har på boendemiljön, genomfördes gedigna litteraturstudier ihop med en fallstudie av Valla Berså. Intervjuer med entreprenörerna och konsulterna genomfördes tillsammans med en enkätundersökning med de boende i Valla Berså. Resultatet tyder på att fördelarna att bygga med KL-trä är många och om bara kunskapsnivån kommer ikapp så har vi ett konkurrenskraftigt material till de traditionella byggmaterialen. Det finns många lösningar för att uppnå tillräcklig brandsäkerhet och goda ljudmiljöer. Rätt utformat kan ett KL-trähus medföra ett mycket gott inomhusklimat med jämn behaglig temperatur och bra luft, med en lägre energiförbrukning och miljöpåverkan som följd.

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    Att bygga och bo i ett flerbostadshus av KL-trä med Valla Berså som referensobjekt
  • 85.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Askoxylakis, Ioannis
    FORTH, Institute of Computer Science, Greece.
    Fowler, Scott
    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.
    Traganitis, Apostolos
    FORTH, Institute of Computer Science, Greece.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Security and Resilience in Cognitive Radio Networks2011In: European Research Consortium for Informatics and Mathematics Magazine, ISSN 0926-4981, no 85, p. 48-49Article in journal (Refereed)
    Abstract [en]

    After more than a decade of research, system securityand resilience is now the major technological barrier forthe Cognitive Radio (CR) to be adopted by the telecommunication industry. New ideas are required tomake CR networks secure and robust against attacks taking advantage the inherent characteristics of the CR functionality. This work explores key points that urgentlyneed to be addressed.

  • 86.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Avgouleas, Ioannis
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Pappas, Nikolaos
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Fitzgerald, Emma
    Lund University, Sweden.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. University of Maryland, MD 20742 USA.
    Allocation of Heterogeneous Resources of an IoT Device to Flexible Services2016In: IEEE Internet of Things Journal, ISSN 2327-4662, Vol. 3, no 5, p. 691-700Article in journal (Refereed)
    Abstract [en]

    Internet-of-Things (IoT) devices can be equipped with multiple heterogeneous network interfaces. An overwhelmingly large amount of services may demand some or all of these interfaces available resources. Herein, we present a precise mathematical formulation of assigning services to interfaces with heterogeneous resources in one or more rounds. For reasonable instance sizes, the presented formulation produces optimal solutions for this computationally hard problem. We prove the NP-completeness of the problem and develop two algorithms to approximate the optimal solution for big instance sizes. The first algorithm allocates the most demanding service requirements first, considering the average cost of interfaces resources. The second one calculates the demanding resource shares and allocates the most demanding of them first by choosing randomly among equally demanding shares. Finally, we provide simulation results giving insight into services splitting over different interfaces for both cases.

  • 87.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Avgouleas, Ioannis
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Pappas, Nikolaos
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Flexible allocation of heterogeneous resources to services on an IoT device2015In: 2015 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), Institute of Electrical and Electronics Engineers (IEEE), 2015, p. 99-100Conference paper (Refereed)
    Abstract [en]

    In the Internet of Things (IoT), devices and gateways may be equipped with multiple, heterogeneous network interfaces which should be utilized by a large number of services. In this work, we model the problem of assigning services' resource demands to a device's heterogeneous interfaces and give a Mixed Integer Linear Program (MILP) formulation for it. For meaningful instance sizes the MILP model gives optimal solutions to the presented computationally-hard problem. We provide insightful results discussing the properties of the results on the properties of the derived solutions with respect to the splitting of services to different interfaces.

  • 88.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Chen, Lei
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A Fully Decentralized and Load-Adaptive Fractional Frequency Reuse Scheme2011In: Modeling, Analysis & Simulation of Computer and Telecommunication Systems (MASCOTS), 2011 IEEE 19th International Symposium on, 2011, p. 425-428Conference paper (Refereed)
    Abstract [en]

    A new fully decentralized dynamic fractional frequency reuse (FFR)-based scheme for cellular OFDMA networks is introduced. FFR is a technique to mitigate inter-cell interference to improve the throughput of interference-limited users on the cell edge, to the expense of the rest of the cell's users and the aggregate throughput. The proposed scheme aims to limit the FFR-incurred loss of the center users' throughput, while still providing sufficient bandwidth for the cell edge users' communication. This is done by local information sharing and distributed optimization. The resulting flexibility of frequency reuse can be especially beneficial in scenarios with non-uniform and time-varying load. The optimization task is accomplished by solving a knapsack problem in each cell, where the goal is to maximize the center throughput while maintaining acceptable degradation on the cell edge with respect to the original FFR allocation. The performance improvement resulting from the distributed and dynamic FFR scheme is demonstrated by snapshot simulations on an 81-cells network with asymmetric cell load. The proposed scheme achieves up to a 62% gain in cell-center throughput with a cost of no more than 18% at the edges when compared to the classic FFR scheme. The overall system throughput improvement ranges from 22% to 58%.

  • 89.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Chen, Lei
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Optimal and Collaborative Rate Selection for Interference Cancellation in Wireless Networks2011In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 15, no 8, p. 819-821Article in journal (Refereed)
    Abstract [en]

    Analysis of wireless systems commonly assumes single-user detection at the receivers. Interference is typically treated as noise. On the other hand, multiuser detection has long been taking advantage of interference cancellation (IC) to increase capacity. We exploit IC by optimal rate selection. Transmission rates are collaboratively optimized to maximize the benefit of IC. A link reduces its rate, if that enables IC to significantly boost the SINR on other links. We provide a complexity analysis and an integer programming model to find the optimal IC pattern. Simulation results indicate that throughput improvement is over 30% in low SINR regimes.

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  • 90.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Efrat, Alon
    University of Arizona, AZ 85721 USA.
    Packer, Eli
    IBM Research Haifa, Israel.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Sedov, Leonid
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    BBTM: New life for old ATM2016In: 2016 IEEE/AIAA 35TH DIGITAL AVIONICS SYSTEMS CONFERENCE (DASC), IEEE , 2016Conference paper (Refereed)
    Abstract [en]

    This paper investigates algorithmic questions related to the possibility of managing UAV traffic with beacon-based navigation, which we dub BBTM - Beacon-Based Traffic Management. The specific problem addressed is: How to install the minimum number of beacons in a mountainous terrain to ensure connectivity among a given set of UAS terminals on the terrain? BBTM is relevant for low-cost UAVs operating in remote areas not on time-critical missions, and may also be used as a backup system for better-equipped UAS in case the precise positioning or control information is lost, spoofed or jammed. We give algorithms for the beacon tower placement and evaluate their performance both on synthetic and real-world terrain data; the experiments suggest that our solutions can be used to efficiently quantify costs of establishing direct-visibility routing networks for UAS management.

  • 91.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Ephremides, Anthony
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    He, Qing
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Minimum-Time Link Scheduling for Emptying Wireless Systems: Solution Characterization and Algorithmic Framework2014In: IEEE Transactions on Information Theory, ISSN 0018-9448, E-ISSN 1557-9654, Vol. 60, no 2, p. 1083-1100Article in journal (Refereed)
    Abstract [en]

    We consider a set of transmitter-receiver pairs, or links, that share a wireless medium and address the problem of emptying backlogged queues with given initial size at the transmitters in minimum time. The problem amounts to determining activation subsets of links, and their time durations, to form a minimum-time schedule. Scheduling in wireless networks has been studied under various formulations before. In this paper, we present fundamental insights and solution characterizations that include: 1) showing that the complexity of the problem remains high for any continuous and increasing rate function; 2) formulating and proving sufficient and necessary optimality conditions of two baseline scheduling strategies that correspond to emptying the queues using one-at-a-time or all-at-once strategies; and 3) presenting and proving the tractability of the special case in which the transmission rates are functions only of the cardinality of the link activation sets. These results are independent of physical-layer system specifications and are valid for any form of rate function. We then develop an algorithmic framework for the solution to this problem. The framework encompasses exact as well as sub-optimal, but fast, scheduling algorithms, all under a unified principle design. Through computational experiments, we finally investigate the performance of several specific algorithms from this framework.

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  • 92.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Ephremides, Anthony
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    He, Qing
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    On Emptying a Wireless Network in Minimum Time2012In: 2012 IEEE International Symposium on Information Theory Proceedings (ISIT), Piscataway, NJ, USA: IEEE , 2012, p. 2671-2675Conference paper (Refereed)
    Abstract [en]

    We consider N transmitter-receiver pairs that share a wireless channel and we address the problem of obtaining a schedule for activating subsets of these links so as to empty the transmitter queues in minimum time. Our aim is to provide theoretical insights for the optimality characterization of the problem, using both a cross-layer model formulation, which takes into account the effect of interference on achievable transmission rates, as well as a collision-based model, which does not incorporate the physical layer realities into the problem. We present the basic linear programming formulation of the problem and establish that the optimal schedule need not consist of more than N subset activation frames. We then prove that the problem is NP-hard for all reasonable continuous rate functions. Finally, we obtain sufficient and/or necessary conditions for optimality in a number of special cases.

  • 93.
    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.

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  • 94.
    Angelakis, Vangelis
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Sajid, Muhammad
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Siddiqui, Imran
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A distributed, load-aware, power and frequency bargaining protocol for LTE-based networks2012In: 2012 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC), Piscataway, NJ, USA: IEEE , 2012, p. 6525-6529Conference paper (Refereed)
    Abstract [en]

    A distributed, load-aware, joint power and frequency allocation protocol is introduced for LTE-based cellular networks, and system-level simulations are performed. Our proposed scheme aims to cooperatively limit the impact of Fractional Frequency Reuse (FFR) on the center users throughput compared to the Reuse 1 scheme, while providing sufficient throughput for the edge users. This is achieved through an asynchronous, lightweight scheme of local message exchange between neighboring LTE eNodeBs. The proposed scheme facilitates a type of "bargain" where an overloaded sector requests permission to utilize its neighbors edge bands for its center users at a limited set of transmit power levels. Grants are generated at each neighbor by solving a small-scale optimization problem. Using an LTE simulator we evaluate our scheme on a network with 21 sectors of varying load patterns. The proposed schemes performance for center users is consistently improved with respect to FFR-3, while for edge users the performance degradation is controlled by a parameter we set in the optimization problems definitions; compared to Reuse 1 edge users still have gains. Specifically, we observed up to a 46% gain in the sectors center throughput with a cost below 9% at the edges when compared to the classic FFR scheme, while the overall system throughput goes up by up to 26% in heavily loaded scenarios.

  • 95.
    Anund, Anna
    et al.
    VTI.
    Kircher, Albert
    VTI.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    The effect of milled rumble strips versus virtual rumble strips on sleepu drivers: A driving simulator study2009Report (Refereed)
  • 96.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Chalkia, Eleni
    Centre of Research and Technology Hellas/Hellenic Institute of Transport, Thessaloniki, Greece.
    Watch Out! Something Precious is Moving2011In: Infrastructure and Safety in a Collaborative World: Road Traffic Safety / [ed] Evangelos Bekiaris, Marion Wiethoff, Evangelia Gaitanidou, Berlin Heidelberg: Springer Berlin/Heidelberg, 2011, 1, p. 233-242Chapter in book (Other academic)
    Abstract [en]

    One critical situation when a driver needs to have a high degree of awareness, to avoid critical situations or crashes, is when passing a school bus, stopped for boarding or de-boarding of children. With the help of an experiment in VTI’s moving base driving simulator, a scenario, using in-vehicle information before the bus was reached, was tested. The aim was to enhance drivers’ perception, in order to reduce the speed of vehicles passing by the stopped bus. Both alert and sleep deprived drivers were tested. The results showed a significant speed reduction thanks to the information given beforehand. Sleep deprivation did not seem to have an impact on speed reduction. This suggests that the warning signals are seen and followed, regardless the drivers’ state of alertness. Thus, it seems likely that this type of information may be useful as an Intelligent Transport System (ITS), to provide driver support about upcoming hazards. One step towards further research in this direction is performed within the EU project SAFEWAY2SCHOOL, the main objectives of which are presented at the end of this chapter.

  • 97.
    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.

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  • 98.
    Arhall, Johanna
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cox, Emmie
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Key Performance Indicators for SAS Flights2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Revenue management is a thoroughly researched field of study and it is widely used in several different industries. The Revenue Management Department at the airline SAS (Scandinavian Airline System) serves to maximise the profit of the company’s flights. At their disposal they have a number of tools, which use KPIs (Key Performance Indicators) as a measurement. The KPIs are used in prognosis to determine future initiatives, and to analyse and verify results. SAS does not know if the KPIs they focus on to measure performance are the most relevant for optimisation of revenue for their flights. In an attempt to simplify the use of SAS’ optimisation system we have performed a correlation analysis on a set of selected KPIs and assessed the influence relationships between these KPIs, in order to identify pivotal KPIs. Furthermore, we have researched origindestination control and the network effect to broaden the scope of the investigation. We have presented the work and the results in this thesis. The correlation analysis was performed using data, spanning a two-year period, for domestic flights (within Sweden) provided by SAS. The results of the analysis showed that the assessed KPIs could be divided into three groups; within each group the KPIs are closely correlated. As a result, we concluded that to focus on one KPI in each group should be adequate for evaluating performance. The three pivotal KPIs are revenue passenger kilometre, cabin factor and revenue per available seat kilometre. We have recommended SAS to continue working with origin-destination control and that the pivotal KPIs should be used as a measurement for the network, as well as measurements such as net leg revenue. Additionally, we have suggested that SAS conducts equivalent or similar analyses in other suitable areas to identify or confirm pivotal KPIs.

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  • 99.
    Aria, Erfan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Investigation of automated vehicle effects on driver’s behavior and traffic performance2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Advanced Driver Assistance Systems (ADAS) offer the possibility of helping drivers to fulfill their driving tasks. Automated vehicles are capable of communicating with surrounding vehicles (V2V) and infrastructure (V2I) in order to collect and provide essential information about driving environment. Studies have proved that automated vehicles have a potential to decrease traffic congestion on road networks by reducing the time headway, enhancing the traffic capacity and improving the safety margins in car following. Furthermore, vehicle movement and driver’s behavior of conventional vehicles will be affected by the presence of automated vehicles in traffic networks. Despite different encouraging factors, automated driving raises some concerns such as possible loss of situation awareness, overreliance on automation and degrading driving skills in absence of practice. Moreover, coping with complex scenarios, such as merging at ramps and overtaking, in terms of interaction between automated vehicles and conventional vehicles need more research. This thesis work aims to investigate the effects of automated vehicles on driver’s behavior and traffic performance. A broad literature review in the area of driving simulators and psychological studies was performed to examine the automated vehicle effects on driver’s behavior. Findings from the literature survey, which has been served as setup values in the simulation study of the current work, reveal that the conventional vehicles, which are driving close to the platoon of automated vehicles with short time headway, tend to reduce their time headway and spend more time under their critical time headway. Additionally, driving highly automated vehicles is tedious in a long run, reduce situation awareness and can intensify driver drowsiness, exclusively in light traffic. In order to investigate the influences of automated vehicles on traffic performance, a microscopic simulation case study consisting of different penetration rates of automated vehicles (0, 50 and 100 percentages) was conducted in VISSIM software. The scenario network is a three-lane autobahn segment of 2.9 kilometers including an off-ramp, on-ramp and a roundabout with some surrounding urban roads. Outputs of the microscopic simulation in this study reveal that the positive effects of automated vehicles 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 decreased by 8.09% during p.m. peak hours in scenario with automated vehicles. Besides, Smoother traffic flow with less queue in the weaving segment was observed. Result of the scenario with 50% share of automated vehicles moreover shows a feasible interaction between conventional vehicles and automated vehicles. Meaningful outputs of this case study, based on the input data from literature review, demonstrate the capability of VISSIM software to simulate the presence of automated vehicles in great extent, not only as an automated vehicle scenario but also a share of them, in traffic network. The validity of the output values nonetheless needs future research work on urban and rural roads with different traffic conditions.

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  • 100.
    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, p. 761-770Conference 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.

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