Digitala Vetenskapliga Arkivet

Change search
Refine search result
1234567 1 - 50 of 7591
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aaboen, Lise
    NTNU, Trondheim.
    BATON-CHANGING ON EGGSHELLS – TRANSFERRING SUPPLIER RELATIONSHIPS WHEN MOVING PRODUCTION2014Conference paper (Refereed)
    Abstract [en]

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

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

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

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

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

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

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

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

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

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

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

    relationship into a more developed state.

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

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

    Download full text (pdf)
    fulltext
  • 3. Aalhuizen, Christoffer
    Potential of V2G in a Rural Low-Voltage Grid on Gotland for Voltage and Power Capacity Control2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish transportation sector needs to undergo major changes in order to achieve the established goals for climate and environment. The largest change is the replacement of fossil-fuelled vehicles to vehicles propelled by renewable energy sources, such as biofuels and electricity. To account for an increase in local electric power consumption, the electric power infrastructure of Sweden needs to adapt through expansion and reconstruction of the electric power grid. However, changes in infrastructure are usually expensive. It is therefore suitable to also examine alternative solutions, which could potentially be more cost efficient. One of these solutions are vehicle-to-grid (V2G), where electric vehicles acts as local electric power control and provides auxiliary services to the electric power grid. This thesis is a case study of a part of a low-voltage electric power grid on Gotland, with the goal of analysing the potential of V2G in the investigated area. The study focused on utilizing V2G for balancing electric power consumption and generation, and for adjusting voltage levels. Simulations of the area were executed in PSS®E for three different cases; one high-load case, low-load case and average-load case. It was found that by utilizing V2G a ramp up of electric power during mornings was delayed by approximately one hour, making the electric power grid potentially more compatible with photovoltaics (PV). However, the overall effects from V2G was fairly low. This outcome can partly be explained by the assumptions made in the report, and also due to some odd behaviour of the system model. 

    Download full text (pdf)
    fulltext
  • 4. Aarsten, Dagrun
    Rapport forprosjekt : 3D-data over og under bakken (RIM)2015Report (Other academic)
    Abstract [nb]

    Vi har belyst at det er store årlige utgifter forbundet med vedlikehold på veg, og kvalitativt sammenliknet tall for Norge og Sverige. Samtidig ligger det en utfordring i at forskjellige typer vedlikeholdsoppgaver går inn under forskjellige avdelinger/budsjetter, slik at det krever internt samarbeid å virkelig belyse mulige totale besparelser ved vedlikehold og utbygging. Når det gjelder utstyr er det gjennomført en studie av flybårne og bilbårne sensorer, med fokus på datainnsamlingsmetoder som kan utføres uten stengning av veg. Samtidig er det utviklet en metode for oppgradering av posisjonssoftware som vil drastisk kunne redusere behovet for landmålte referansepunkter selv i områder uten satellittdekning (tunnel) som vil åpne helt nye muligheter for nøyaktig og effektiv dokumentasjon av infrastruktur. For visualisering, forvaltning og bruk av data er det studert en rekke kommersielle løsninger i tillegg til TerraTecs egenutviklede TerraView. Fordeler og ulemper med forskjellige verktøy er veid opp mot hverandre. Det er utarbeidet innspill til hva en slik type modell bør inneholde, og hvordan strukturen bør bygges opp, presenteres og forvaltes basert på konkrete innspill fra Trafikverket ut i fra deres behov.

    Download full text (pdf)
    Rapport forprosjekt : 3D-data over og under bakken (RIM)
  • 5.
    Aban, Kevin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Göst, Jens
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Analysis of transports with pharmaceuticals on Arlanda airport2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

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

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

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

  • 7.
    Abate, Megersa
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    Determinants of Capacity Utilisation in Road Freight Transportation2014In: Journal of Transport Economics and Policy, ISSN 0022-5258, E-ISSN 1754-5951, Vol. 48, p. 137-152Article in journal (Refereed)
    Abstract [en]

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

  • 8.
    Abate, Megersa
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    De Jong, Gerard
    University of Leeds.
    The optimal shipment size and truck size choice: The allocation of trucks across hauls2014In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 59, p. 262-277Article in journal (Refereed)
    Abstract [en]

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

  • 9.
    Abate, Megersa
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    Vierth, Inge
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    de Jong, Gerard
    University of Leeds.
    Joint econometric models of freight transport chain and shipment size choice2014Report (Other academic)
    Abstract [en]

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

    Download full text (pdf)
    fulltext
  • 10.
    Abate, Megersa
    et al.
    Statens väg- och transportforskningsinstitut, Transportekonomi Stockholm, TEK-S.
    Vierth, Inge
    Statens väg- och transportforskningsinstitut, Transportekonomi Stockholm, TEK-S.
    de Jong, Gerard
    University of Leeds.
    Joint econometric models of freight transport chain and shipment size choice2014Report (Other academic)
    Abstract [en]

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

    Download full text (pdf)
    FULLTEXT01
  • 11.
    Abate, Megersa
    et al.
    World Bank.
    Vierth, Inge
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Karlsson, Rune
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    de Jong, Gerard
    University of Leeds.
    Baak, Jaap
    dSignificance.
    A disaggregate stochastic freight transport model for Sweden2018In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, p. 1-26Article in journal (Refereed)
    Abstract [en]

    This paper presents estimation results for models of transport chain and shipment size choice, as well as an implementation of the estimated disaggregate models (for two commodity groups), in the context of the national freight transport model for Sweden. The new model is a disaggregate and stochastic (logit) model, whereas the existing Swedish national model is deterministic. One advantage of the new approach is that it bases the underlying behavior of shippers on a stronger empirical foundation (that is micro-data from the Swedish Commodity Flow Survey, CFS). Another advantage is that it overcomes a well-known disadvantage of deterministic models that lead to implausibly large responses to changes in scenario or policy variables. Although estimation and implementation of aggregate stochastic models were done before, in the context of a national freight transport forecasting model, we think this is the first implementation of disaggregate freight transport chain and shipment size models estimated on choice data for individual shipments, certainly in Europe. We carried out a number of model runs with both versions of the implemented model to compare elasticities and found that transport cost and time elasticities for tonne-km are smaller (in absolute values) in the disaggregate stochastic model than in their deterministic counterparts.

  • 12.
    Abate, Megersa
    et al.
    VTI.
    Vierth, Inge
    VTI.
    Karlsson, Rune
    Jong, Gerard de
    Baak, Jaap
    Estimation and implementation of joint econometric models of freight transport chain and shipment size choice2016Report (Other academic)
    Abstract [en]

    Som en del av utvecklingen av det svenska nationella godstransportmodellsystemet (SAMGODS) utvecklades en stokastisk logistikmodell i form av en disaggregerad modell (random utility model) för val av transportkedja och sändningsstorlek, baserade på svenska Varuflödesundersökningen 2004/2005. Övergången från den nuvarande deterministiska modellen till en stokastisk modell är viktigt eftersom den stokastiska modellen har en starkare empirisk grund. Den deterministiska modellen baserar inte på företagens observerade beslut utan förutsätter att lösningen med de lägsta (operativa) kostnaderna alltid väljs. Vi har uppskattat s.k. logit modeller som förklarar det kombinerade valet av sändningsstorlek (i diskreta viktklasser) och transportkedja för sexton olika varugrupper. En transportkedja (t ex väg- järnväg-väg) är en kombination av de transportmedel som används för att frakta en sändning mellan två platser. Transportkostnaden, transporttiden och sändningens värdedensitet är bland de viktigaste förklarande faktorerna. Probabilistiska modeller tar även hänsyn till effekten av utelämnade faktorer. Däremot förutsätter deterministiska modeller att man kan bortse från den stokastiska komponenten och att forskaren känner till samtliga faktorer som påverkar företagens beslut och att det inte finns någon slumpmässighet i beteendet. Genom att lägga till stokastiska komponenter i random utility modeller blir svarsfunktioner (uttryckt i sannolikheter) jämna i stället för att samlas vid 0 och 1 (som i den deterministiska modellen). Detta kan lösa problemet med over shootings som kan uppträda i den deterministiska modellen när man testar olika transportpolitiska åtgärder. Modellskattningar (av transportkedja och sändningsstorlek) för årliga företag till företag flöden av varugrupperna metallprodukter och kemiska produkter implementerades i SAMGODS. För varje företag till företag flöde beräknades sannolikheten att vissa transportkedjor och sändningsstorlekar väljs; dessa aggregeras till zon to zon flöden i PC-matrisen (PC = production consumption). Aggregerade OD matriser (OD = origin destination) i form av tonkilometer per trafikslag (och varugrupp) beräknas. Valet av omlastningspunkter modellerades med en deterministisk ansats eftersom Varuflödesundersökningen inte innehåller uppgifter om val/lokalisering av terminaler. De implementerade stokastiska modellerna för metallprodukter och kemiska produkter används för att beräkna elasticiteter till följd av ändrade kostnader för väg-, järnvägs- och sjötransporter. De beräknade elasticiteterna jämförs med motsvarande i elasticiteter för metallprodukter och kemiska produkter i den deterministiska modellen och i litteraturen. Elasticiteterna är som förväntat i allmänhet lägre (i absoluta tal) i den stokastiska modellen än i den deterministiska modellen. Länk: http://swopec.hhs.se/ctswps/abs/ctswps2016_001.htm

    Download full text (pdf)
    Estimation and implementation of joint econometric models of freight transport chain and shipment size choice
  • 13.
    Abbasi, Maisam
    et al.
    Lund University.
    Nilsson, Fredrik
    Lund University.
    Waidringer, Jonas
    Chalmers.
    Outlook of Complexity and Complication on Logistics and Supply Chain Management2009In: NOFOMA 2009, Jönköping Sweden: Nofoma , 2009Conference paper (Refereed)
  • 14.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of nanostructured particles in railway tunnels2013Report (Other academic)
  • 15.
    Abdeljaber, O.
    et al.
    Qatar University, Doha, Qatar.
    Younis, Adel
    Qatar University, Doha, Qatar.
    Alhajyaseen, W.
    Qatar University, Doha, Qatar.
    Analysis of the Trajectories of Left-turning Vehicles at Signalized Intersections2020In: Transportation Research Procedia, 2020, Vol. 48, p. 1288-1295Conference paper (Refereed)
    Abstract [en]

    Internationally, an annual number of more than a million fatalities are caused by road traffic crashes, with particularly signalized intersections being crash prone locations within the highway system. An accumulation of conflicts between drivers is caused by the different movements (through and turning) from different directions at the intersection; hence, studying the trajectories of turning vehicles is an important step towards improving traffic safety performance of these facilities. In view of that, the current paper aims at providing further insight into the behaviour of left-turning vehicles (right-hand traffic rule) at signalized intersections in the State of Qatar. At first, a total of 44 trajectories of free-flowing vehicles were manually extracted from a recorded video for a single approach of Lekhwair signalized intersection in Doha City, State of Qatar. After that, the extracted trajectories were statistically analysed in an attempt to explore the factors affecting the path of left-turning vehicles at signalized intersections. The results suggest that the characteristics of the extracted paths are significantly related to the vehicle’s entry speed, minimum speed throughout its turning manoeuvre, and the lateral distance between the exit point and the curb (i.e., targeted exit lane). Provided that the speed parameters can be fairly an indication to the driving behaviour, it can be concluded that the driver’s attitude plays an important role in drawing the manoeuvre of a turning vehicle as does the pre-selection of the exit lane. Finally, the effort presented in this paper can be regarded as a way forward towards understanding the behaviour of turning vehicles at signalised intersection in the State of Qatar.

  • 16.
    Abdeljaber, O.
    et al.
    Linnaeus University, Växjö, Sweden.
    Younis, Adel
    Qatar University, Doha, Qatar.
    Alhajyaseen, W.
    Qatar University, Doha, Qatar.
    Extraction of Vehicle Turning Trajectories at Signalized Intersections Using Convolutional Neural Networks2020In: The Arabian Journal for Science and Engineering, ISSN 1319-8025, Vol. 45, no 10, p. 8011-8025Article in journal (Refereed)
    Abstract [en]

    This paper aims at developing a convolutional neural network (CNN)-based tool that can automatically detect the left-turning vehicles (right-hand traffic rule) at signalized intersections and extract their trajectories from a recorded video. The proposed tool uses a region-based CNN trained over a limited number of video frames to detect moving vehicles. Kalman filters are then used to track the detected vehicles and extract their trajectories. The proposed tool achieved an acceptable accuracy level when verified against the manually extracted trajectories, with an average error of 16.5 cm. Furthermore, the trajectories extracted using the proposed vehicle tracking method were used to demonstrate the applicability of the minimum-jerk principle to reproduce variations in the vehicles’ paths. The effort presented in this paper can be regarded as a way forward toward maximizing the potential use of deep learning in traffic safety applications.

  • 17.
    Abdeljaber, Osama
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology. Qatar University, Qatar.
    Younis, Adel
    Qatar University, Qatar.
    Alhajyaseen, Wael
    Qatar University, Qatar.
    Analysis of the Trajectories of Left-turning Vehicles at Signalized Intersections2020In: Recent Advances and Emerging Issues in Transport Research / [ed] Fusun ULENGİN, Gopal R. PATIL, Ozay OZAYDIN, Lóránt TAVASSZY, Ashish VERMA, Elsevier, 2020, p. 1288-1295Conference paper (Refereed)
    Abstract [en]

    Internationally, an annual number of more than a million fatalities are caused by road traffic crashes, with particularly signalized intersections being crash prone locations within the highway system. An accumulation of conflicts between drivers is caused by the  different  movements  (through  and  turning)  from  different  directions  at  the  intersection;  hence,  studying  the  trajectories  of  turning vehicles is an important step towards improving traffic safety performance of these facilities. In view of that, the current paper aims at providing further insight into the behaviour of left-turning vehicles (right-hand traffic rule) at signalized intersections in the State of Qatar. At first, a total of 44 trajectories of free-flowing vehicles were manually extracted from a recorded video for a  single  approach  of  Lekhwair  signalized  intersection  in  Doha  City,  State  of  Qatar.  After  that,  the  extracted  trajectories  were statistically analysed in an attempt to explore the factors affecting the path of left-turning vehicles at signalized intersections. The results suggest that the characteristics of the extracted paths are significantly related to the vehicle’s entry speed, minimum speed throughout its turning manoeuvre, and the lateral distance between the exit point and the curb (i.e., targeted exit lane). Provided that the speed parameters can be fairly an indication to the driving behaviour, it can be concluded that the driver’s attitude plays an important role in drawing the manoeuvre of a turning vehicle as does the pre-selection of the exit lane. Finally, the effort presented in this paper can be regarded as a way forward towards understanding the behaviour of turning vehicles at signalised intersection in the State of Qatar.

    Download full text (pdf)
    fulltext
  • 18.
    Abdeljaber, Osama
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Younis, Adel
    Qatar University, Qatar.
    Alhajyaseen, Wael
    Qatar University, Qatar.
    Extraction of Vehicle Turning Trajectories at Signalized Intersections Using Convolutional Neural Networks2020In: Arabian Journal for Science and Engineering, ISSN 2193-567X, Vol. 45, p. 8011-8025Article in journal (Refereed)
    Abstract [en]

    This paper aims at developing a convolutional neural network (CNN)-based tool that can automatically detect the left-turning vehicles (right-hand traffic rule) at signalized intersections and extract their trajectories from a recorded video. The proposed tool uses a region-based CNN trained over a limited number of video frames to detect moving vehicles. Kalman filters are then used to track the detected vehicles and extract their trajectories. The proposed tool achieved an acceptable accuracy level when verified against the manually extracted trajectories, with an average error of 16.5 cm. Furthermore, the trajectories extracted using the proposed vehicle tracking method were used to demonstrate the applicability of the minimum-jerk principle to reproduce variations in the vehicles’ paths. The effort presented in this paper can be regarded as a way forward toward maximizing the potential use of deep learning in traffic safety applications.

    Download full text (pdf)
    fulltext
  • 19.
    Abdella, Juhar Ahmed
    et al.
    UAEU, U Arab Emirates.
    Zaki, N. M.
    UAEU, U Arab Emirates.
    Shuaib, Khaled
    UAEU, U Arab Emirates.
    Khan, Fahad
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, Faculty of Science & Engineering.
    Airline ticket price and demand prediction: A survey2021In: Journal of King Saud University - Computer and Information Sciences, ISSN 1319-1578, Vol. 33, no 4, p. 375-391Article in journal (Refereed)
    Abstract [en]

    Nowadays, airline ticket prices can vary dynamically and significantly for the same flight, even for nearby seats within the same cabin. Customers are seeking to get the lowest price while airlines are trying to keep their overall revenue as high as possible and maximize their profit. Airlines use various kinds of computational techniques to increase their revenue such as demand prediction and price discrimination. From the customer side, two kinds of models are proposed by different researchers to save money for customers: models that predict the optimal time to buy a ticket and models that predict the minimum ticket price. In this paper, we present a review of customer side and airlines side prediction models. Our review analysis shows that models on both sides rely on limited set of features such as historical ticket price data, ticket purchase date and departure date. Features extracted from external factors such as social media data and search engine query are not considered. Therefore, we introduce and discuss the concept of using social media data for ticket/demand prediction. (c) 2019 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

    Download full text (pdf)
    fulltext
  • 20.
    Abdul-Rahman, William
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Product Development, Production and Design.
    Andersson, Viktor
    Jönköping University, School of Engineering, JTH, Industrial Product Development, Production and Design.
    Conceptual design and development of an off-road cargo trailer for bicycles2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report presents the conceptual development of an off-road cargo trailer designed for usage in conjunction with bicycles when camping. The objective of the study is to address the limitations of existing cargo trailers and thereafter create a trailer that efficiently can navigate off-road terrains while carrying various types of cargo. The research includes collecting data regarding user behaviours and desired functions an optimal trailer should obtain and was translated into user requirements. The result demonstrates the successful development of an off-road cargo trailer on a conceptual level that offers innovative solutions and improved load-carrying capacity in comparison to the available market, while considering factors such as weight, manoeuvrability, and ease of use. This research contributes to the field by presenting data, which can be used in development and a comprehensive solution that expands the possibilities for bicycle-based cargo transportation in off-road environments. Future work can include further refinements to optimise the trailer’s performance and address additional user requirements based on the data presented.

    Download full text (pdf)
    fulltext
  • 21.
    Abed, Hanna
    et al.
    Malmö University, Faculty of Culture and Society (KS), Department of Urban Studies (US).
    Obradovac, Edim
    Malmö University, Faculty of Culture and Society (KS), Department of Urban Studies (US).
    Just in Time och Samlastning: Logistiska strategier för ökad effektivitet, minskade kostnader och förbättrad responsivitet2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The purpose of this study is to deepen the knowledge and understanding of the strategies “just in time” and “freight pooling” in logistics management in the food industry. In order to answer the purpose, we had two different research questions. The questions are about what advantages and disadvantages there are with these strategies in the food industry. The study is conducted in a qualitative way where the interviews and observations are used to deepen the knowledge of how an organization in food industries uses the strategies “just in time” and “freight pooling”. The previous science shows that there are some advantages with these strategies but also disantvages that the organization should have in mind and work with so that they do not happen. The study shows that the organization this study was conducted on where very successful in implementing these strategies and they experienced many advantages by using “just in time” and “freight pooling”. The organization this study was conducted on were really cautious with the possible setbacks that the strategies can so they emphasized that they need to work really close with all the involved parties so that they can minimize the risk for the disadvantages to happen. 

    Keywords: just in time, pooling, logistic strategies, transport optimization, food supply chain

    Download full text (pdf)
    fulltext
  • 22.
    Abenoza, Roberto
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning. Department of Transport and Planning, Delft University of Technology, P.O. Box 5048, GA Delft, 2600, Netherlands.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment. KTH, School of Industrial Engineering and Management (ITM), Centres, Integrated Transport Research Lab, ITRL.
    Determinants of traveler satisfaction: Evidence for non-linear and asymmetric effects2019In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 66, p. 339-356Article in journal (Refereed)
    Abstract [en]

    Classifying public transport service attributes based on their influence on overall traveler satisfaction can assist stakeholders and practitioners in introducing cost-efficient measures. To date most studies employed methods that were based on the assumption that the impact of service attributes on traveler satisfaction is entirely linear and symmetric. This study examines whether service attributes have a non-linear and asymmetric influence on the overall travel experience by employing the Three-factor theory (basic, performance and exciting factors). The analysis is conducted for different traveler segments depending on their level of captivity, travel frequency by public transport and travel mode used, and is based on a relatively large sample size collected for Stockholm County. Moreover, the estimated models control for important socio-demographic and travel characteristics that have been insofar overlooked. Results are presented in the form of a series of multi-level cubes that represent different essentiality of traveler needs which provide a useful methodological framework to further design quality service improvements that can be applied to various geographical contexts. Our findings highlight that a “one size fits all” approach is not adequate for identifying the needs of distinct traveler segments and of travelers using different travel modes. Furthermore, two-thirds of the attributes are consistently classified into the same factor category which entails important policy implications. This research deepens and expands the very limited knowledge of the application of the three-factor theory in the transport field.

  • 23.
    Abenoza, Roberto
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, System Analysis and Economics.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport Planning, Economics and Engineering. TU Delft.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, System Analysis and Economics.
    How does travel satisfaction sum up?: Decomposing the door-to-door experience for multimodal trips2018In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, Vol. 46, no 5, p. 1615-1642Article in journal (Other academic)
    Abstract [en]

    Understanding how satisfaction with individual trip legs aggregates to the overall travel experience for different types of trips will enable the identification of the trip legs that are most impactful. For this purpose we analyze data on retrospective evaluations of entire multi-modal trip experiences and satisfaction with individual trip legs. We formulate and describe alternative aggregation rules and underpin them in theory and previous empirical findings. The results of a series of regression models show that for a large number of multi-modal trip configurations normative rules can better reproduce overall travel satisfaction than heuristic rules. This indicates that all trip legs need to be considered when evaluating the overall travel experience, especially for trips legs involving waiting and/or transferring time. In particular, weighting satisfaction with individual trip legs with perceived trip leg durations yielded the best predictor of overall travel satisfaction. No evidence for a disproportional effect of the last or most exceptional part of the trip was found. This research contributes to the literature on combining multi-episodic experiences and provides novel empirical evidence in the transport domain. 

  • 24.
    Abenoza, Roberto
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, System Analysis and Economics.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport Planning, Economics and Engineering. TU Delft.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, System Analysis and Economics.
    Investigating the nature of Public Transport service attributes2018In: Transportation Science, ISSN 0041-1655, E-ISSN 1526-5447Article in journal (Refereed)
    Abstract [en]

    Classifying public transport service attributes based on their influence on overall traveler satisfaction can assist stakeholders and practitioners in introducing cost-efficient measures. To date most studies employed methods that were based on the assumption that the impact of service attributes on traveler satisfaction is entirely linear and symmetric. This study examines whether service attributes have a non-linear and asymmetric influence on the overall travel experience by employing the Three-factor theory (basic, performance and exciting factors). The analysis is conducted for different traveler segments depending on their level of captivity, travel frequency by public transport and travel mode used, and is based on a relatively large sample size collected for Stockholm County. Moreover, the estimated models control for important socio-demographic and travel characteristics that have been insofar overlooked. Results are presented in the form of a series of multi-level cubes that represent different essentiality of traveler needs which provide a useful methodological framework to further design quality service improvements that can be applied to various geographical contexts. Our findings highlight that a “one size fits all” approach is not adequate for identifying the needs of distinct traveler segments and of travelers using different travel modes. Furthermore, two-thirds of the attributes are consistently classified into the same factor category which entails important policy implications. This research deepens and expands the very limited knowledge of the application of the three-factor theory in the transport field.

  • 25.
    Abenoza, Roberto F.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Liu, C.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering. Delft University of Technology, Netherlands.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    What is the role of weather, built-environment and accessibility geographical characteristics in influencing travelers’ experience?2019In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 122, p. 34-50Article in journal (Refereed)
    Abstract [en]

    We examine the effect of weather, accessibility and built-environment characteristics on overall travel experience as well as the experience with the latest trips. These are factors that are often disregarded in the travel satisfaction literature even though they are believed to largely influence the first mile of the door-to-door trip. This study fills a research gap in investigating all these factors by using, amongst other, a relatively large travel satisfaction survey from years 2009 to 2015 and by focusing on urban and peri-urban geographical contexts, the city and county of Stockholm (Sweden), respectively. The ordered logit model results show that county dwellers living close to a metro station and in well linked-to-all areas report higher overall travel satisfaction evaluations. In addition, precipitation and ground covered with snow have a negative influence on travel satisfaction. Our findings indicate that built-environment characteristics exert a rather weak influence on the travel experience, especially in the peri-urban context. However, some aspects such as living in areas with medium densities, low income and with high safety perceptions around public transport stations are associated with higher satisfaction levels. In turn, areas with single land uses are found to have lower travel satisfactions. These results are important for public transport planners and designers in devising measures to prevent and mitigate the negative outcome of some weather conditions and to conceive better designed transit oriented developments.

  • 26.
    Abenoza, Roberto F.
    et al.
    KTH.
    Liu, Chengxi
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Cats, Oded
    KTH.
    Susilo, Yusak O.
    KTH.
    What is the role of weather, built-environment and accessibility geographical characteristics in influencing travelers’ experience?2019In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 122, p. 34-50Article in journal (Refereed)
    Abstract [en]

    We examine the effect of weather, accessibility and built-environment characteristics on overall travel experience as well as the experience with the latest trips. These are factors that are often disregarded in the travel satisfaction literature even though they are believed to largely influence the first mile of the door-to-door trip. This study fills a research gap in investigating all these factors by using, amongst other, a relatively large travel satisfaction survey from years 2009 to 2015 and by focusing on urban and peri-urban geographical contexts, the city and county of Stockholm (Sweden), respectively. The ordered logit model results show that county dwellers living close to a metro station and in well linked-to-all areas report higher overall travel satisfaction evaluations. In addition, precipitation and ground covered with snow have a negative influence on travel satisfaction. Our findings indicate that built-environment characteristics exert a rather weak influence on the travel experience, especially in the peri-urban context. However, some aspects such as living in areas with medium densities, low income and with high safety perceptions around public transport stations are associated with higher satisfaction levels. In turn, areas with single land uses are found to have lower travel satisfactions. These results are important for public transport planners and designers in devising measures to prevent and mitigate the negative outcome of some weather conditions and to conceive better designed transit oriented developments.

  • 27.
    Abenoza, Roberto F.
    et al.
    KTH.
    Romero-Torres, J.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning. Delft University of Technology, Netherlands.
    Susilo, Y. O.
    User experiences and perceptions of women-only transport services in Mexico2020In: Gendering Smart Mobilities, Taylor and Francis , 2020, p. 188-209Chapter in book (Other academic)
    Abstract [en]

    Personal safety perceptions impact upon not only travellers’ behaviour and satisfaction but may also diminish their general well-being and health. These effects are particularly negative among female travellers, a group which feels especially vulnerable from certain types of aggression. To tackle women’s personal safety problems several cities around the world introduced transport for women only. Data from Mexico City and its metropolitan area is used to examine how the characteristics of female travellers and of their trips impact upon travel satisfaction with public transport for women only for different travel modes (metro, city bus, and metropolitan BRT) and users based on their previous victimisation. This chapter demonstrates that female travellers’ appreciation of public transport for women only services varies as a function of some of their socio-demographic and travel characteristics (some age groups, trip purposes, and travel frequency). Considering the strength of the marginal effect’s coefficient from a number of ordered logit models three travel attributes should be prioritised: (1) level of satisfaction with travelling with women only, (2) reducing exposure to verbal aggressions, (3) and meeting travellers’ waiting time expectations. This study may help stakeholders identify, target, and prioritise female travellers’ groups which are least satisfied with the service. In addition, this chapter provides some policy recommendations and highlights the role of infrastructure that may help improve the overall travel experience. 

  • 28.
    Abid, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.). Högskolan i Gävle, Sweden.
    Bengtsson, Lars
    Dabhilkar, Mandar
    Factors affecting shifts in global supply chain networks: A configurational approach2013In: Proceedings of the 20th International Annual EurOMA conference, Dublin, Ireland, 9-12 June 2013, 2013, 2013Conference paper (Refereed)
    Abstract [en]

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

  • 29.
    Abourraja, Mohamed Nezar
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics. Ecole Cent Casablanca, Casablanca, Morocco..
    Rouky, Naoufal
    Euro-Mediterranean University, Fez, Morocco.
    Kornevs, Maksims
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Meijer, Sebastiaan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Kringos, Nicole
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges. Euro Mediterranean Univ, Fes, Morocco..
    A simulation-based decision support framework devoted to Ro-Ro terminals: Design, implementation and evaluation2023In: Computers & industrial engineering, ISSN 0360-8352, E-ISSN 1879-0550, Vol. 180, p. 109248-, article id 109248Article in journal (Refereed)
    Abstract [en]

    As a type of intermodal terminal, pure Ro-Ro terminals are one of the most important logistic hubs in the supply chain for rolling freight stored in containerized and wheeled steel boxes. These large-scale systems are highly complex, with nonlinear and hard-to-predict behavior evolving in a stochastic environment. Consequently, making decisions about any problem thereof is no mean feat, particularly for terminal planners. To assist them in decision-making, a pool of relevant models and tools have been developed over the years in the literature. Nevertheless, models that are oriented toward specific objectives dominate, and generic ones are rare. This paper tries to fill this gap and proposes a generic framework to be used as a factory to create specific decision support models based on simulation for pure Ro-Ro terminals. This framework is formulated following two artifacts: (1) the known classification of key performance indicators combined with the typical functional and physical organization of pure Ro-Ro terminals; (2) the three main arteries of harbor systems, namely flows, decisions and operations. Then a scalable way of making decisions based on a flexible form of the cost function weighted according to a set of coefficients is integrated. These designed coefficients allow decision-makers a wide flexibly in choosing how the best solutions are determined. An application of this framework is illustrated through a real case study, where the weights are estimated using an expert-profiling based approach then pushed into the OptQuest optimizer to be calibrated before analyzing the results. These results are aggregated, then expressed as scores on a scale of 0 to 1. This is to help terminal planners to easily identify the worst and best planning scenarios as well as the relationships and compatibilities between the involved handling rules to suggest different alternatives for managing operations.

  • 30.
    Abrahamsson, Mats
    Linköping University, Department of Management and Engineering, Logistics & Quality Management. Linköping University, Faculty of Science & Engineering.
    Logistik för ökad svensk konkurrenskraft: Forsknings- och innovationsagenda för framtidens logistik2013Report (Other academic)
    Abstract [sv]

    Framtidens logistik står inför mycket stora utmaningar som har direkt bäring på svenska företags och organisationers förmåga till tillväxt, hållbarhet och konkurrenskraft. 

    Det står utom all tvivel att logistikens betydelse kommer att öka ännu mer i framtiden. Vinnare på de globala, rörliga marknaderna kommer ett vara de flödeseffektiva företagen, som har förmåga att hantera förändringarna på marknaden med en effektiv logistik som grund. För att lyckas behövs ett Logistiklyft för Sverige, med ett medvetet fokus på att utveckla de dynamiska förmågorna i företag och organisationer. Detta gäller i de allra flesta branscher och typ av företag.

    Den här innovations- och forskningsagendan utgår från den svenska traditionen och internationellt sett unika kunskapen och förmågan att med en systemsyn som grund designa, utveckla och styra komplexa system där flera olika kompetenser samverkar. Logistikens systemkunskap handlar om att lära sig att utforma och styra omfattande och allt mer komplexa försörjningskedjor (supply chains) från råvara till slutkund i syfte att öka svenska företags internationella konkurrenskraft och förmåga att växa på ett miljömässigt och ekonomiskt hållbart sätt

    Agendan adresserar behovet av kompetens och kunskap för mer innovativ logistikutveckling som följer:

    • Utveckling av kunskap om nya och mer innovativa logistiksystem och modeller för industri & handel 
    • Tjänsteutveckling för transport/logistik och IT-företag som stöd för mer innovativa logistiksystem, men också att ta till vara och stimulera den omfattande tjänsteutveckling som finns i förnyelsen av svenskt näringsliv, t ex mot högre grad av e-handel. 
    • Tillämpning av befintliga logistikkunskaper för områden och sektorer i behov av ett logistiklyft och ökad flödeseffektivitet, t.ex. logistik för små- och medelstora företag (SME) med fokus på HUR (genomförandeprocesser) istället för VAD (utformning av koncept och modeller). 
    • Utveckling av kunskaper om hur logistiksystem kan bidra till en hållbar utveckling, såväl miljömässigt som socialt.
    • Utveckling av kunskap om och tillämpning av logistiklösningar med primär samhällsnytta, t ex sjukvårdslogistik och citylogistik samt effektiv och hållbar försörjning av livsmedel, energi etc.

    Den här forsknigs- och innovationsagendan är utvecklad i samarbete mellan Linköpings Universitet, Lunds Tekniska Högskola, Chalmers Tekniska Högskola och en lång rad företag där Axis, SKF, Volvo och Nobel Biocare har funnits med i projektets styrgrupp. 

    Agendan finns endast som PDF. Kontakta Mats Abrahamsson, Linköpings Universitet. mats.abrahamsson@liu.se

    Download full text (pdf)
    Logistik för ökad svensk konkurrenskraft
    Download (png)
    presentationsbild
  • 31.
    Abrishami, Mahdi
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Dynamic Link Flow Estimation according to Historical Travel Times2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Vast application of ITS and the availability of numerous on-road detection devices has resulted in variety of alternative data sources to be exploited and used in the field of traffic modelling. In this thesis, historical travel times, as an alternative data source, is employed on the developed method to perform dynamic network loading. The developed method, referred to as DNLTT, uses the share of each route available in the route choice set from the initial demand, as well as link travel times to perform the network loading. The output of the algorithm is time-dependent link flows. DNLTT is applied on Stockholm transportation network, where it is expected to have variation in link travel times in different time-periods, due to network congestion. In order to calculate the route shares, a time-sliced OD matrix is used. The historical travel times and the routes in the route choice set are extracted from an existing route planning tool. An available logit model, which considers the route travel time as the only logit parameter, is used for the route share calculation and the network loading is performed according to 2 different methods of DNLTT and DL. The evaluation of results is done for a toy network, where there happen different network states in different time-periods. Furthermore, the model output from Stockholm case study is analyzed and evaluated. The dynamic behavior of DNLTT is studied by analysis of link flows in different time-periods. Furthermore, the resulting link flows from both network loading methods are compared against observed link flows from radar sensors and the statistical analysis of link flows is performed accordingly. DNLTT exhibits a better performance on the toy network compared to DL, where the increasing link travel times cause the link flows to decline in different time-periods. However, the output of the developed method does not resemble the observed link flows for the investigated links in Stockholm case study. It is strongly believed, that the performance of DNLTT on the investigated transportation network potentially improves, in case the historical travel times better resemble the network dynamics. In addition to a more reliable data set, an OD adjustment process in all the time-periods is believed to generate better model output.

    Download full text (pdf)
    Dynamic Link Flow Estimation according to Historical Travel Times
  • 32.
    Abubakr, Raowa
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Patel, Pooja
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Packaging systems decision makin; to assure cost efficient transports2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Download full text (pdf)
    Packaging systems
  • 33.
    Ada Fatemeh, Rezai
    Luleå University of Technology, Department of Social Sciences, Technology and Arts.
    Improving The Production Forecasts: Developing a Forecasting Model Using Exponential Smoothing2024Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This research is motivated by identified gaps in contemporary planning practices and

    production processes within firms. Relying solely on experiential knowledge has proven

    limiting, necessitating a more systematic approach. Previous instances of data anomalies,

    particularly ongoing challenges in achieving satisfactory delivery reliability, have underlined

    the need for deeper insights into underlying patterns.

    The objectives of this study are:

    • To identify and analyze specific obstacles and challenges affecting load balance

    and delivery security in Borl.nge's production system.

    • To explore various methods or strategies aimed at enhancing the process of

    generating reliable capacity forecasting methods.

    Both primary and secondary research methods were employed. Primary methods

    included interviews and the development of a forecast model, while secondary studies

    encompassed the latest research in the field.

    The thesis revealed five primary factors hindering capacity attainment:

    1. WIP(work in progress)/ slabs material shortages disrupt production flow and

    escalate costs due to the need for external sourcing of slabs.

    2. Transport issues, including incorrect internal deliveries and the weather

    conditions, pose challenges.

    3. Personnel shortages hinder the efficient utilization of production capacity.

    4. Machine breakdowns result in production interruptions, leading to capacity loss

    and inefficiency.

    5. Inventory problems, such as insufficient capacity and poor management,

    impede smooth production operations.

    Additionally, the second objective was addressed by implementing exponential

    smoothing for capacity planning forecasts. By updating forecasts every 13 weeks, this study

    improves the production forecast.

    Download full text (pdf)
    fulltext
  • 34.
    Adedokun, Adeyemi
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Application of Road Infrastructure Safety Assessment Methods at Intersections2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

    Download full text (pdf)
    fulltext
  • 35.
    Adell, Emeli
    et al.
    Trivector Traffic, Sverige.
    Fors, Joakim
    Trivector Traffic, Sverige.
    Exponering av oskyddade trafikanter med hjälp av app-baserade resvaneundersökningar2024In: Sammanställning av referat från Transportforum 2024 / [ed] Fredrik Hellman; Mattias Haraldsson, Linköping: Statens väg- och transportforskningsinstitut , 2024, p. 287-288Conference paper (Other academic)
    Abstract [sv]

    Trafiksäkerhetsarbetet har kommit långt i Sverige, men det finns stora utmaningar kvar vad gäller oskyddade trafikanters trafiksäkerhetssituation. Trafiksäkerhetsrisken baseras på antalet olyckor eller personskador per trafikant, trafikarbete eller annat exponeringsmått. För oskyddade trafikanter är dock förståelsen av exponering begränsad och det finns generellt ett behov av bättre förståelse för oskyddade trafikanters exponering i termer av reslängder, tid i olika trafikmiljöer.

    Samtidigt som kunskapsläget kring skyddade trafikanters exponering i allmänhet är låg ger ökad digitalisering nya sätt att förstå människors resvanor och användning av trafiksystemet. I app-baserade resvaneundersökningar används positioneringsdata från mobiltelefonen, vilket kan ge värdefull information om exponering men också annan trafiksäkerhetsrelevant information, så som hastigheter.

    Denna studie har undersökt om data från app-baserade resvaneundersökningar kan använts för att ge värdefull information om a) den oskyddade trafikantgruppen, b) exponering och c) annan trafiksäkerhetsrelevant information. Underlaget har varit en kommunal app-baserad resvaneundersökning. Fokus har varit cyklister. Positioneringsdata har knutits till infrastrukturen via map-matching mot en geografisk databas. Genom detta kan typ av infrastruktur (till exempel gång- och cykelvägnät) och infrastrukturens olika egenskaper (till exempel hastighetsgränser) knytas till varje enskild del av en resa. Hastigheter har beräknats hjälp av GPS-positionering och tidsangivelser utmed hela resans sträckning. Vi har i denna studie valt att beräkna hastigheter på 50-meterssektioner, vilket bedöms ge en bra bild över hastighetsprofilen över resan.

    Det är med hjälp av data från app-baserad resvaneundersökning möjligt att beskriva hur mycket olika typer av individer cyklar, både i antal resor, reslängd och restid, både totalt och fördelat över dygnet. Den geografiska informationen gör det dessutom möjligt att förstå i vilken trafikmiljö som resor sker. I denna studie har vi analyserat hur mycket av transportarbetet som skett på olika typer av infrastruktur, vilket kan ställas i relation till var olyckor och skador skett för att beräkna trafiksäkerhetsrisker på olika typer av infrastruktur. I detta fall har vägtyp och hastighetsgräns använts, men det skulle också kunna vara typ av korsning om den data finns tillgänglig i den digitala beskrivningen av infrastrukturen.

  • 36.
    Adell, Emeli
    et al.
    Trivector Traffic AB, Sweden.
    Runesson, Helena
    Lunds kommun, Sweden.
    Mårtensson, Malin
    Trivector Traffic AB, Sweden.
    Linse, Leif
    Trivector Traffic AB, Sweden.
    Trana, Anders
    Future by Lund, Sweden.
    D'Agostino, Carmelo
    Transport and Roads, Department of Technology and Society, LTH, Lund University, Sweden.
    Investigating untapped bike potential with crowdsourcing data2024In: Sammanställning av referat från Transportforum 2024 / [ed] Fredrik Hellman; Mattias Haraldsson, Linköping: Statens väg- och transportforskningsinstitut , 2024, p. 488-489Conference paper (Other academic)
    Abstract [en]

    The city of Lund has a high share of trips done by bicycle, and ambitious goals of becoming climate-neutral by 2030. Still the municipality, like many other cities, has difficulty in reaching the goals of increasing cycling and needs to find the real potential. To understand the untapped cycling potentials of a city, and generally to promote it, it is important to first assess how bike is used and why. This can be done by observing the bike flows and understanding the reasons for the use or misuse of bikes as a transport mode. Particularly, for the scope of identifying untapped potential, the preferred time scale should be smaller than the traditional count based on annual average figures. Also, opposite to motorized traffic, bicycle volume can rapidly change inside a city. All this caused the need to search for more effective methods to estimate bicycle volume like crowdsourcing data that can be provided by mobile apps which are usually collected for other purposes. The present study introduces a method of bicycle volume estimation based on GPS data from the TravelVu application, an app-based tool to collect travel survey data. 

    A spatial analysis has been chosen to investigate the correlation between the data from the Lund municipality counting and the GPS data from TravelVu app. The analysis has been performed by comparing the average daily bike volume with the aggregated data in 3 months for the GPS track. Counting data refers to 2018 and 2021 and the TravelVu data refers to 3 months starting from August 2018 and 2021, where 2018 data are collected through crowdsourcing and 2021 are random sampling. All the weekend data have been removed since the manual counting was always carried out during weekdays (and should be represented by those). At first, all the data from the Lund municipality report were digitalized in a GIS map and then clustered per intersection to have a more robust regression when compared to the TravelVu data and to reduce the possible spatial errors.  

  • 37.
    Adelsköld, Astrid
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Review of general demand responsive transport in Sörmland county2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

    Download full text (pdf)
    fulltext
  • 38.
    Aderot, Tommy
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Effektiva offentliga upphandlingar för ökad industrialisering inom anläggningsbranschen: En fallstudie på Trafikverket2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I Sverige står de offentliga upphandlingarna för cirka 625 miljarder kronor per år. För att styra de offentliga upphandlingarna mot politiska mål har regeringen tagit fram en nationell upphandlingsstrategi som bland annat beskriver hur offentliga upphandlingar kan främja innovation och alternativa lösningar för att öka produktiviteten. Inom exempelvis anläggningsbranschen har utredningar visat en låg ökning i produktivitet jämfört med den tillverkande industrin. En stor del av anläggningsarbetena upphandlas av offentliga beställare vilket innebär att potential finns att påverka entreprenörernas produktivitet. För att öka produktiviteten föreslås industrialiserade metoder. Slutprodukterna är dock komplexa och för att minska komplexiteten anser litteraturen att både processer och produkter bör standardiseras.

    Syftet med studien var att undersöka hur offentliga upphandlingar kan främja industrialisering inom anläggningsbranschen och utfördes som en fallstudie på myndigheten Trafikverket. Trafikverket upphandlar årligen för cirka 40 miljarder kronor och är därmed Sveriges största beställare av infrastruktur. Trafikverkets Beställar- och upphandlarstrategi innehåller bland annat strategin industriell produktion. I och med detta finns potential att påverka entreprenörerna att använda industriella produktionsmetoder och därför ansågs myndigheten lämplig att undersöka i den här studien. Tolv upphandlingar undersöktes och datainsamlingen utfördes genom 35 kvalitativa intervjuer med upphandlare, projektledare och entreprenörer. Intervjuerna analyserades genom kodning för att underlätta jämförelse samt för att möjliggöra kvantifiering av svaren.

    En slutsats är att oavsett om upphandlingen är tänkt att främja industrialisering eller inte, försöker entreprenörerna alltid arbeta industriellt. Detta visas i två fall där entreprenören ansåg att förutsättningar för industrialisering saknas, trots detta användes industriella arbetsmetoder. Vidare är den största påverkande faktorn för industrialisering paketering av liknande objekt eftersom detta skapar återupprepningseffekter. Faktorer som däremot hindrar industrialisering är Trafikverkets regler och styrning, konstruktionens utformning samt variationer i omgivningen. Intervjuerna visade även varierande kunskapsnivå gällande begreppet industriell produktion samt en diskrepans mellan Trafikverkets och entreprenörernas uppfattning gällande vilka främjande faktorer som upphandlingarna skapat.

    Förbättringsförslagen består av tre delar och handlar om att skapa intern samsyn gällande begreppet industriell produktion genom att standardisera arbetssättet och arbeta med ständig utveckling genom erfarenhetsåterföring. Vidare bör Trafikverket beakta interna förutsättningar för att exempelvis öka entreprenörens frihetsgrader samt utreda vilka verksamhetsområden samt vilka konstruktioner som är mer lämpliga för industrialisering. Slutligen rekommenderas att inkludera entreprenören tidigt i processen, exempelvis genom marknadsdialoger för att öka kunskapsnivån genom erfarenhetsåterföring från tidigare projekt samt för att skapa dialog kring begreppet industriell produktion.

    Download full text (pdf)
    fulltext
  • 39.
    Adolfsson, Lovisa
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Nilsson, Rebecca
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Collection structure design of deposited PET bottles and aluminium cans in northern Sweden2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

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

    Download full text (pdf)
    Collection structure design of deposited PET bottles and aluminium cans in northern Sweden
  • 40.
    Adolfsson, Rasmus
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Hannercrantz, André
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Optimering av orderstorlek ur ett kostnads- och produktivitetsperspektiv: en kvantitativ fallstudie på Zoégas i Helsingborg2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate optimal order quantities at the coffee producer Zoéga’s packaging lines in Helsingborg. The company is currently unaware of how order quantities affect their production; with regards to productivity as well as setup- and holding costs. With a long-term vision of incorporating “pull planning”, the case company also needs to evaluate the capabilities of their current production system.

    The case study mainly addresses two areas; one comparing historical productivity in relation to order quantity, and one determining optimal order quantity with the scheduling-tool known as “Economic lot scheduling problem”. One of the packaging lines results in a classic case of “Basic period approach”, a problem frequently reviewed in ELSP-literature. The other lines have sequence dependent setup times, which required a more complex model. The primarily data collection has been from internal production- and management systems.

    The ELSP-results generated optimal order quantities and production schedules for all packaging lines. The study also found statistically significant correlations between order quantity and productivity for Zoéga’s. These correlations compiled upper and lower limits for the most productive order quantities; where most of the ELSP-quantities placed inside these limits. Finally, the study shows that by implementing these suggestions, Zoéga’s could speed up their product turnover and be better prepared for “pull planning” implementation in the future.

    Download full text (pdf)
    fulltext
  • 41.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning.
    Impact on urban form by the localization of railway stations: Evidence from Sweden2019In: Cities, ISSN 0264-2751, E-ISSN 1873-6084, Vol. 95, article id 102362Article in journal (Refereed)
    Abstract [en]

    Since the 1990s a number of new railway stations have been established in Sweden on new or rerouted lines, while other stations have been reconstructed at their original locations. Some stations were located in urban surroundings, others in semi-urban or peripheral locations depending on the trade of between regional speed, and local urban circumstances. The urban form consequences depending on station localisation of these transport infrastructure investments are nonetheless unknown. In order to provide a basis for future planning, this research aims to provide knowledge on urban form consequences of relocating railway stations. 13 stations were selected in a case study. Changes in urban densities from 1993 to 2013 were analysed by a combination of kernel techniques and estimation of monocentric density models. Stations within an urban and semi-urban environments show strong agglomeration tendencies. Within peripheral environments, the urban development was unclear or even negative. In an urban environment, the location of the station still attracted more urban resources compared to the location of the urban density centre. These findings should be understood in the light of a market-oriented socio-economic context since 1990th influencing the planning system and the development of urban form.

  • 42.
    Afridi, Amjad
    et al.
    Skellefteå Municipality, Sweden; Department of Building Materials, KTH Royal Institute of Technology, Stockholm, Sweden.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure.
    Management of municipal street network in Sweden: results from a national survey2024In: Sammanställning av referat från Transportforum 2024 / [ed] Fredrik Hellman; Mattias Haraldsson, Linköping: Statens väg- och transportforskningsinstitut , 2024, p. 395-396Conference paper (Other academic)
    Abstract [en]

    Management of street networks is different from state roads due to its multifunctional role in society. This requires timely maintenance of the street network to improve socioeconomic development. Municipalities in Sweden are responsible for the management of about 42000 km of street network in their jurisdiction. Maintenance budget and resources vary from municipality to municipality depending on their network size, geographical location, and population density. 

    A questionnaire was sent to all 290 municipalities across the country to investigate the street network and pavement management practices at the municipal level. An in-depth interview of 14 municipalities took place afterwards. A total of 51% of responses were officially received to highlight the frequently and infrequently occurring pavement distresses and their causes. Furthermore, the study highlights the maintenance approaches and allocation of budget to manage the street network. Lastly, the study highlights the factors which need to be addressed to improve street network management.   

    Visual assessment of pavements is common and the use of pavement management system (PMS) is not only limited but also lacks pavement performance prediction models. Common pavement distresses are excessive formation of potholes, surface unevenness and alligator distress among the municipalities. Frequent causes of distress include the ageing of the street network, heavy vehicles, patching and high traffic flow. Furthermore, cold climate and population density are important factors in the degradation process. Allocation of maintenance and reconstruction budget is relatively high in municipalities located in the north. Densely populated municipalities have higher taxpayers’ contributions to maintenance and reconstruction. Other major issues are limited resources and maintenance of budget, which adversely affect the maintenance backlog and the choice of maintenance alternatives, ultimately the decision-making. This restricts the use of preventive maintenance among the municipalities. 

    Municipalities are required to improve the frequency and quality of pavement data collection, enhance the sophistication of PMS by using pavement deterioration models, and increase the maintenance budget and resources. An insight into the capabilities of municipalities would help in long-term strategic planning and effective utilisation of the maintenance budget to improve the street network across the country.  

  • 43.
    Aghighi, Meysam
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Bäckström, Christer
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Cost-optimal and Net-benefit Planning: A Parameterised Complexity View2015In: 24th International Joint Conference on Artificial Intelligence (IJCAI-15), IJCAI-INT JOINT CONF ARTIF INTELL, ALBERT-LUDWIGS UNIV FREIBURG GEORGES-KOHLER-ALLEE, INST INFORMATIK, GEB 052, FREIBURG, D-79110, GERMANY , 2015, p. 1487-1493Conference paper (Refereed)
    Abstract [en]

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

    Download full text (pdf)
    fulltext
  • 44.
    Agrawal, Tarun Kumar
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Kalaiarasan, Ravi
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Olhager, Jan
    Lund University.
    Wiktorsson, Magnus
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Understanding Supply Chain Visibility Through Experts’ Perspective: A Delphi Based Approach2021In: Advances in Production Management Systems. Artificial Intelligence for Sustainable and Resilient Production Systems: IFIP WG 5.7 International Conference, APMS 2021, Nantes, France, September 5–9, 2021, Proceedings, Part IV / [ed] Alexandre Dolgui, Alain Bernard, David Lemoine, Gregor von Cieminski, David Romero, Cham: Springer Nature , 2021, Vol. 633, p. 189-196Conference paper (Refereed)
    Abstract [en]

    Visibility in production logistics and across the supply chain has become a key concern for organizations. Its need has been further emphasized due to the current COVID 19 crisis. Organizations find it challenging to prepare the internal logistics and supply chain, and quickly respond to such unexpected events, due to low visibility. Against this backdrop, the paper, which is a work-in-progress, systematically documents different factors influencing supply chain visibility and crucial information that should be collected and shared among supply chain partners for better visibility. A Delphi analysis is being conducted with twenty-six supply chain experts from various globally recognized enterprises with manufacturing units located worldwide. The study starts with a short open-ended questioner to collect a comprehensive list of antecedents, drivers, barriers, effects, and visibility information based on the qualitative response from the experts. The preliminary results from the first round of the Delphi analysis indicate that risk management, environmental sustainability, and supply chain control are some of the key drivers. Lack of IT infrastructure and maturity are some of the barriers, integrated systems, and technology maturity are among the key antecedents and gaining planning capability and better customer service are some of the positive effects of supply chain visibility as per the experts’ opinion. In addition, information related to planning, supplier location, and deviation are among the crucial ones that require the collection and sharing for better supply chain visibility. This research study is among the few that empirically explores factors influencing supply chain visibility and generates new insights as to why the barriers can be difficult to overcome in complex supply chain settings.

  • 45. Agrawal, Tarun Kumar
    et al.
    Kumar, Vijay
    University of Borås, Faculty of Textiles, Engineering and Business.
    Pal, Rudrajeet
    University of Borås, Faculty of Textiles, Engineering and Business.
    Wang, Lichuan
    College of Textile and Clothing Engineering, Soochow University, 215168-Suzhou, China.
    Chen, Yan
    College of Textile and Clothing Engineering, Soochow University, 215168-Suzhou, China.
    Blockchain-based Framework for Supply Chain Traceability: A Case Example of Textile and Clothing Industry2021In: Computers & industrial engineering, ISSN 0360-8352, E-ISSN 1879-0550Article in journal (Refereed)
    Abstract [en]

    Traceability has emerged as a prime requirement for a multi-tier and multi-site production. It enables visibility and caters to the consumer requirements of transparency and quality assurance. Textile and clothing industry is one such example that requires traceability implementation to address prevailing problems of information asymmetry and low visibility. Customers find it difficult to access product data that can facilitate ethical buying practices or assure product authenticity. Besides, it is challenging for stakeholders to share crucial information in an insecure environment with risk of data manipulations and fear of losing information advantage. In this context, this study investigates and proposes a blockchain-based traceability framework for traceability in multi-tier textile and clothing supply chain. It conceptualizes the interaction of supply chain partners, and related network architecture at the organizational level and smart contract and transaction validation rules at the operational level. To illustrate the application of the proposed framework, the study presents an example of organic cotton supply chain using blockchain with customized smart contract and transaction rules. It finally demonstrates the applicability of the developed blockchain by testing it under two parameters. The proposed system can build a technology-based trust among the supply chain partners, where the distributed ledger can be used to store and authenticate supply chain transactions. Further, the blockchain-based traceability system would provide a unique opportunity, flexibility, and authority to all partners to trace-back their supply network and create transparent and sustainable supply chain.

    Download full text (pdf)
    fulltext
  • 46.
    Agriesti, Serio
    et al.
    Aalto University, Espoo, Finland; Tallinn University of Technology Tallinn, Estonia.
    Kuzmanovski, Vladimir
    Aalto University, Espoo, Finland; Tallinn University of Technology Tallinn, Estonia.
    Hollmén, Jaakko
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences. Aalto University Espoo, Finland.
    Roncoli, Claudio
    Aalto University, Espoo, Finland.
    Nahmias-Biran, Bat-Hen
    Tel Aviv University Tel Aviv, Israel.
    A Bayesian Optimization Approach for Calibrating Large-Scale Activity-Based Transport Models2023In: ieee open journal of intelligent transportation systems, ISSN 2687-7813, Vol. 4, p. 740-754Article in journal (Refereed)
    Abstract [en]

    Addressing complexity in transportation in cases such as disruptive trends or disaggregated management strategies has become increasingly important. This in turn is resulting in the rising adoption of Agent-Based and Activity-Based modeling. Still, a broad adoption is hindered by the high complexity and computational needs. For example, hundreds of parameters are involved in the calibration of Activity-Based models focused on behavioral theory, to properly frame the required detailed socio-economical characteristics. To address this challenge, this paper presents a novel Bayesian Optimization approach that incorporates a surrogate model defined as an improved Random Forest to automate the calibration process of the behavioral parameters. The presented solution calibrates the largest set of parameters yet, according to the literature, by combining state-of-the-art methods. To the best of the authors' knowledge, this is the first work in which such a high dimensionality is tackled in sequential model-based algorithm configuration theory. The proposed method is tested in the city of Tallinn, Estonia, for which the calibration of 477 behavioral parameters is carried out. The calibration process results in a satisfactory performance for all the major indicators, the OD matrix average mismatch is equal to 15.92 vehicles per day while the error for the overall number of trips is equal to 4%.

  • 47.
    Ahlberg, Joakim
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Intermodala transporter: definition, aktörer och omfattning2016Report (Other academic)
    Abstract [en]

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

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

    Download full text (pdf)
    fulltext
  • 48.
    Ahlberg, John
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cruz Wolter Håkansson, Christoffer
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Identification, mapping and control of non-structure-bound materials2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

    Download full text (pdf)
    fulltext
  • 49.
    Ahlepil, Erik
    et al.
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Björck, Joel
    Linköping University, Department of Management and Engineering, Logistics & Quality Management.
    Evaluating Distribution Structures for Overseas Export of Frozen Food.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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

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

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

    Download full text (pdf)
    fulltext
  • 50. Ahlman, Tryggve
    Incident-reporting system ForeSea: Development of a Maritime safety system2019Report (Other academic)
    Abstract [en]

    The safe operation of ships and the safe handling of cargo are core principles for shipping companies. In addition to focusing on the safety of their own operations, shipping companies take steps to protect the public health and safety in the countries they transit. Safety in shipping has improved significantly in the last decade with shipping losses declining by more than 50% since 2005. While ship owners might only work reactively with safety, the Scandinavian approach has been to establish pro-active methods of working with safety involving humans and learning from each other. Svensk Sjöfart, together with the Swedish Transport Agency, has made a joint effort and created ForeSea – an information system on accidents, incidents and near misses at sea. The common incident database transparency, knowledge transfer and shared knowledge is prevailing. What distinguishes ForeSea from other systems is that the information in the database can be used for identification of safety analyzes of specific events, thus contributing to preventive maritime safety. The main goal of the ForeSea system is to reduce risks of maritime accidents, by sharing and transferring safety information between operators and management. Allowing formulation of safety analyses, assessments and safety reports. The main objective of the project has been to perform quality assurance of the system, analyze methods, ensure availability for research project and software training modules, make adaption; technical interface and system customization as well as IT improvements, training materials and dissemination. This report outlines the work and findings of the ForeSea 2.0 - Development of a Maritime safety system project as performed during the year of 2017 and 2018. Humans, especially the crews have an important role in the safe operation of ships. The crews, given the right circumstances are able to safely maneuver, navigate, maintain and operate the vessel. The crews are dependent on many factors that enable this work, from the design of the vessel and work place, the procedures, processes given by the ship management and the business approach the ship owner applies to the vessel. The introduction of more automation requires a systems perspective and will not be a straight forward development. Total autonomy as proposed by some technology developers is often neglecting the functions and roles that humans have on maritime safety and the business case for increased automation neglects the full contribution of humans onboard. Total autonomy will therefore require high-end products that are built on standardized complex systems. Controlling and monitoring these systems will set new requirements on operators to uphold situated understanding in these complex systems. Many aspects will be affected by increased automation towards smart shipping - regulations, organization, workplace, working methods, HMI, roles and skills. To cope with the foreseen changes, it is important to develop further training, skills, experience, openness in the organization and familiarization giving the future crews the right pre-conditions to succeed in the future, as well as mindful design and integration of newly automated systems In the future, the ISM code will likely have to change to improve the interaction between land organisations and crews in order to facilitate better integration of split responsibilities and split physical locations by the management system which in the long run allows for an increased land-based monitoring and control of vessels’ systems and move certain tasks to shore to lower workload onboard, which should be one of the main drivers for automation. The results from this project ensure the quality of the tools and the output and the communication via the new homepage (https://foresea.org/), folders and roll-ups ensures a smooth dissemination and spreading.

    Download full text (pdf)
    Incident-reporting system ForeSea: Development of a Maritime safety system
1234567 1 - 50 of 7591
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf