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Towards optimal railway track utilization based on societal benefitSvedberg, Victoria January 2018 (has links)
Infrastructure managers in railway systems are striving to have as efficient track utilization as possible. There are no unanimous interpretation of efficiency in terms of track utilization, but the aim of the Swedish Transport Administration is to allocate track capacity such that societal benefit is maximized. This means that the tracks should be used by as much traffic as possible and by traffic that provides as much benefit for the society as possible. To allocate track capacity such that the track utilization is optimal would be an easy task if the track capacity were not a scarce resource. Today, many train operators share railway network and there are cases when two or more operators want to use the same track capacity at the same time. The infrastructure manager must then make priorities and reject some operators, and the question is which operators to reject. The guiding principle is to grant the operators that provide the highest societal benefit access to the tracks. However, the question would then change into how to know which operator that provides the highest societal benefit. In this thesis, the societal benefit of publicly subsidized traffic is estimated using social cost-benefit analysis. Mathematical models and methods are developed for quantifying and computing the number of departures for the publicly subsidized traffic and their distribution in time, i.e. a train timetable, that provides the maximal societal benefit in a social cost-benefit analysis setting. The societal benefit of commercial traffic is estimated using the market value for their requested train timetables. The market value is set using dynamic pricing. A suggestion of a dynamic pricing process that can be used in the train timetabling process is described. Mathematical models and methods for calculating the supply and demand of a track access request are developed and tested, which enables the use of a dynamic pricing process on track capacity / Samhällsekonomiskt effektiv fördelning av järnvägskapacitet
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Simulation based evaluation of flexible transitLeffler, David January 2019 (has links)
Transport authorities are faced with the challenge of making effective use of existing transportation infrastructure under increasing needs of transport accessibility, sustainability, and safety. The ongoing growth and adoption of shared mobility options, the anticipation of automated vehicles, and the increased availability of real-time data brought on with the developments of Intelligent Transport Systems, have all inspired many innovations in public transit design. The integration of these technologies in existing public transit holds great potential for operational planning and control, but is also notoriously difficult to evaluate. In the included papers, flexible operational policies that make use of real-time data and connected vehicles are developed and assessed through the extension of an existing public transit simulation framework, BusMezzo. Paper I explores the incorporation of flexibility in fixed urban transit via real-time short-turning, a fleet management strategy not often studied in a real-time context. In this paper, a decision rule for when and where a short-turn should occur based on predicted passenger costs is developed and evaluated in a case study of a bidirectional urban bus line in Stockholm, Sweden. Paper II focuses on the design and analysis of an automated feeder service. In this paper an extension of BusMezzo with a module for simulating a variety of flexible transit operations is presented. Estimated reductions in on-board crew costs with vehicle automation motivate a case study of two vehicle fleets where a fully demand-responsive operational policy is compared against fixed route and schedule operations. / Transportmyndigheter står inför utmaningen att effektivt utnyttja befintlig transportinfrastruktur under växande behov av tillgänglighet, hållbarhet och säkerhet. Den pågående tillväxten och anammandet av delad mobilitet, förväntningarna på automatiserade fordon, samt den ökade tillgången till realtidsdata tack vare utvecklingen av Intelligenta Transportsystem, har inspirerat många innovationer inom kollektivtrafikdesign. Att integrera dessa tekniker inom befintliga kollektivtrafiksystem innebär en stor potential för operativ planering och styrning, men effekterna av dessa satsningar är notoriskt svåra att utvärdera. De inkluderade uppsatserna utvecklar flexibla operativa strategier som utnyttjar realtidsdata och uppkopplade fordon, och utvärderar dessa genom en utvidgning av ett existerande simuleringsramverk för kollektivtrafik, BusMezzo. Uppsats I utforskar en utökning av flexibilitet inom kollektivtrafik i tätort med fasta rutter och tidtabeller genom realtids-kortvändning, en strategi för att samordna fordon som inte ofta studeras inom en realtidskontext. I artikeln utvecklas en beslutsregel för när och var en kortvändning ska ske baserad på förväntade passagerarkostnader. Beslutsregeln utvärderas i en fallstudie av en befintlig busslinje i Stockholm. Uppsats II fokuserar på design och analys av en automatiserad matartjänst. I artikeln presenteras en utvidgning av BusMezzo i form av en modul för att simulera olika varianter av flexibel operativ styrning. Förväntade sänkningar av bemanningskostnader genom automatisering av fordon motiverar en fallstudie av två fordonsflottor, där en fullt efterfrågestyrd operativ strategi jämförs med drift enligt fast rutt och tidtabell. / <p>QC20190514</p> / CTR - Trafikeffekter av automatisering
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Towards microscopic models for bicycle traffic simulationPérez Castro, Guillermo January 2023 (has links)
As bicycling becomes an integral part of sustainable mobility, it becomes essential to enhance planning strategies that ensure bicycling as an efficient mode of transport. While traffic simulation has been extensively utilized for traffic planning of various modes of transport, this type of modeling support is largely lacking in the planning of bicycle traffic. Given the high heterogeneity in the characteristics of bicyclists, the use of microscopic traffic simulation, which incorporates the explicit inclusion of individual properties and preferences, becomes particularly useful for evaluating bicycle traffic performance. By examining real-world traffic, the objective of this thesis is to investigate essential requirements for microscopic modeling and simulation of bicycle traffic on off-street bicycle path segments, and to further develop and evaluate modeling approaches suitable for bicycle traffic. Understanding the fundamentals of how bicyclists interact with the infrastructure and other bicyclists is a necessary step towards accurate simulation of bicycle traffic. In this thesis, research gaps related to the evaluation of bicycle traffic performance and simulation are identified, and methods to validate bicycling data are proposed to determine its quality and suitability for traffic analysis. Furthermore, two distinct modeling approaches are investigated to simulate the impact of gradients in bicycle traffic. The first involves calibrating a car-based model using a widely-used microscopic traffic simulation software, and the second implements a power-based model rooted in the physical forces acting on a bicycle. Lastly, characteristics of bicycle traffic that are relevant for simulating bidirectional traffic are identified and described. The work in this thesis offers a starting point towards enhanced microscopic bicycle traffic simulation that effectively assist the planning of efficient bicycle traffic.
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Evaluation and implementation of charge infrastructure for electric aircraft / Utvärdering och implementering av laddinfrastruktur för elflygplanBerg, Edvin, Haglind, Sebastian January 2023 (has links)
<p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
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Transport buyers’ perspective on electric road freight : Barriers and benefits with battery electric trucks, and actions that can be performed by the transport buyers to contribute to the transitionRylander, Ingrid, Andersson, Simon January 2023 (has links)
Today the diesel-driven truck is the most used type of transportation of freight. Diesel-driven trucks emit carbon dioxide and other particles, leading to environmen- tal problems and people inhaling the emissions. To decrease the carbon footprint of road freight, one solution is to transition to trucks powered by electric engines. For the transition to happen, the transport buyers must be on board since they often set the level of importance for environmental aspects. To get the transport buyers to support the transition towards electric road freight, knowing what they find important when selecting suppliers and what they could do to contribute to the change is essential. This is why the purpose of the thesis is as follows. This thesis aims to identify what factors transport buyers prioritise when selecting a transport supplier and what actions transport buyers can take to contribute to the transition towards battery electric road freight. Ten large Swedish companies that procure road freight transport were interviewed in a case study to answer the purpose. The purpose was broken down into three research questions. The first targeted what factors transport buyers find important when procuring transportation. The second question focused on the transport buy- ers’ views regarding what barriers and benefits they see with transitioning to electric road freight. The last research question aimed to answer what actions transport buyers could take to contribute to the transition toward using battery electric road freight as a means of transportation. The study showed that the three most important factors when selecting a supplier were factors related to price, quality and environment. The environment has gained a lot of importance during the last couple of years and has changed the most for the transport buyers’ procurement of transportation. The most significant barri- ers for transport buyers to transition towards electric road freight was the lack of charging infrastructure and the uncertainty of who will take responsibility for the infrastructure development. The most significant benefit of transitioning was the reduced environmental footprint, which allowed for an improved brand value and allowed the companies to market themselves as sustainable. The study also showed that the actions that the transport buyers are most likely to perform, as well as most likely to have a positive impact on the transition towards electric freight vehicles, are collaborating with others and using longer contracts with the LSPs. More extended contracts would be something that could make the LSPs feel secure enough to commit to more significant investments such as BETs. Still, if a relationship between the LSP and the transport buyer reaches far back, the transport buyers think the connection would be more secure for the LSP than a more extended contract. Collaboration is the action with the most potential to make the transition towards battery-electric road freight happen. It has the most potential to overcome the most significant barrier for electric freight vehicles, the lack of infrastructure to charge them.
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Managing Variable Patient Flows at HospitalsOlsson, Olle January 2014 (has links)
Healthcare is a large industry faced with major challenges, such as decreasing inpatient bed numbers and increases in the share of elderly people, which require improved efficiency and effectiveness. The organisation of hospitals normally comprises highly specialised clinical departments, through which patient flows are managed. Since patient flows often involve several clinical departments, this requires much coordination both in space and time. With every individual patient having different diseases, severity levels and responses to therapy, the variability in patient flows has an impact on the inflow, internal flow and outflow at clinical departments and hospitals. Historically, healthcare resources have not been adapted to these variations. The purpose of this licentiate thesis is therefore to explore how variable patient flows are managed in hospitals. This comprises how variable patient flows affect hospitals as well as how variable patient flows are handled. It also includes the organisational configuration, and the influence it has on the actions used to handle variable patient flows in hospitals. Both the hierarchical levels, roles and teams that make decisions and manage the flow of patients as well as the actions used to handle variable patient flows at hospitals are included in the research. Hence, an approach where the hospital is regarded as a system is used, an approach often described as a system perspective. Three research methods have been used in this licentiate thesis. The first research method used was simulation modelling, to study how changes in an acute patient flow affected an emergency department and inpatient ward at a small hospital. A case study at a university hospital was performed to study both the actions used to handle variable patient flows as well as the influence of the organisational configuration. Several literature reviews, both structured and unstructured, has also been made to compare and evaluate the results from the empirical data. There are several effects of variable patient flows. The case study indicates that increased patient flow variability leads to increases in bed utilization variability and thereby problems with bed shortages. Mismatches between patient inflow and outflow, in terms of number of patients, also lead to bed shortages. Literature reviews also show that bed shortages in inpatient wards are a major cause of overcrowding in emergency departments. The results from the simulation model point toward emergency departments being more adapted to variable patient inflow than inpatient wards. To handle these issues there is a need for flexibility when providing healthcare services, something suggested in the literature. 50 actions used at the university hospital to handle variable acute patient flows were identified in the research. A majority of these are used to handle the effects of the variation, not the variation itself. Nor is it effects of individual variations, such as patient inflow, that are handled but the combined effect of the variations in several variables. For example, much time and effort are spent handling bed shortages. One third of the actions are used at a hospital level, with the aim to have positive effects for the hospital as a whole. Two thirds are used and developed at a departmental level, with the aim to improve the situation at the clinical department by using the action. By having most of the actions used at individual clinical departments, without considering the impact on whole hospital, there is an obvious risk of sub-optimization. One explanation for many actions being used at a departmental level could be that there is lack of strategic direction and decision-making ability at top management level due to the use of unanimous decision-making in the hospital management group. This hinders the control and coordination of the actions used at different clinical departments, rendering them more similar to separate organisations. Departmental collaboration is also impeded as well as organisational learning at the hospital, both bottom-up and sideways in the hierarchies, encumbering the development and sharing of successful actions for handling variable patient flows.
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Construction site productivity performance measurement - Capturing the impact of construction logisticsWeideryd, Sandra January 2022 (has links)
<p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
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Congestion Effects in Transport Modelling and ForecastingWest, Jens January 2015 (has links)
Transport investments and policies are increasingly turned towards dealing with transport congestion rather than with shortening the potential free flow travel time. However, appraisal methodologies for projects meant to reduce congestion are relatively less well developed compared to methodologies for projects aiming to reduce travel times. Static assignment models are for instance incapable of predicting the build-up and dissipation of traffic queues and capturing the experienced crowding caused by uneven on-board passenger loads. Despite of the availability of dynamic traffic assignment and despite of fairly concrete ideas of how integration with demand models could take place, only few model systems have been developed for real applications. The predicted reduction of traffic volume across the Gothenburg congestion charge cordon in the peak, 11%, turned out to be an accurate estimate of the observed reduction, 12%. The reduction in the off-peak, however, was overpredicted, as it was also in the Stockholm case. To analyse congestion charges in Stockholm it is necessary and fully possible to integrate DTA with the demand model. In the performed tests it could be seen that both tested models had problems replicating the flow on the main bypass early in the morning but otherwise performed well. A case study of a metro extension in Stockholm demonstrated that congestion effects constitute more than half of the total benefits and that these effects are excessively underestimated by a conventional static model. Effects of various operational measures can be analysed with BusMezzo and the results have been validated against observed data. The findings indicate that all three tested measures in a case study (boarding through all doors, headway-based holding and bus lanes) had an overall positive impact on service performance and that there are synergetic effects. Using a continuous VTT distribution and hierarchical route choice was demonstrated as a successful method of modelling the multi-passage rule implemented in Gothenburg congestion charges and was shown to give realistic predictions of route choice effects. First results from integration of DTA with a travel demand model for the Stockholm region show that even without systematic calibration the DTA is in reasonable agreement with observed traffic counts and travel times. The presented experiments did not reveal a striking difference between using a macroscopic and a microscopic assignment package. While travel time savings are often the only benefit included in public transport project appraisals, the best practice assigns weighted value of time to average load/capacity measures. However, failure to represent dynamic congestion effects may lead to substantial underestimation of the benefits of projects primarily designed to increase capacity rather than reduce travel times. The impact of small operational measures should not be underestimated. These measures are relatively cheap compared to investments in new transit infrastructure and large societal gains can therefore be achieved by their implementation. / Investeringar och åtgärdsprogram inom transportområdet handlar allt oftare om att råda bot på trängsel snarare än att minska potentiella friflödesrestider. Utvärderingsmetoder för projekt som syftar till att minska trängsel är dock mindre utvecklade än metoder för projekt som syftar till att minska restider. Statiska nätutläggningsmodeller är till exempel inte lämpade för att prognosera uppbyggnad och avveckling av köer eller för att fånga upplevd trängsel orsakad av ojämn belastning på kollektivtrafikfordon. Trots förekomsten av dynamisk trafikutläggning och trots tämligen konkret kunskap om hur integration med efterfrågemodeller kunde gå till, finns det endast ett fåtal modellsystem utvecklade för verklig tillämpning. Den predikterade trafikflödesminskningen på 11 % över trängselskattesnittet i Göteborg visade sig stämma väl överens med den observerade minskningen på 12 %. Minskningen under lågtrafik visade sig dock vara överskattad, precis som i Stockholmsfallet. För att analysera trängseleffekter i Stockholm är det nödvändigt och fullt möjligt att integrera en DTA-modell med efterfrågemodellen. I de utförda testerna observerades att båda de testade modellerna hade problem med att återskapa korrekta flöden på Essingeleden under morgonens maxtimme, men i övrigt gav god överensstämmelse. I en fallstudie av blå tunnelbanelinjes förlängning i Stockholm visade det sig att trängseleffekter utgjorde mer än hälften av de totala nyttorna och att dessa effekter är kraftigt underskattade i en konventionell statisk modell. Effekter av olika operationella åtgärder kan analyseras med BusMezzo och resultaten har blivit validerade mot observerade data. Resultaten tyder på att alla tre testade åtgärder i en fallstudie (ombordstigning i alla dörrar, turtäthetsbaserad reglering och busskörfält) hade en positiv inverkan på servicenivån och att det förekommer synergieffekter dem emellan. Användandet av kontinuerlig tidsvärdesfördelning och hierarkiskt ruttval har framgångsrikt demonstrerats som en metod för att modellera flerpassageregeln i Göteborgs trängselskattesystem och visade sig ge realistiska prediktioner av ruttvalseffekter. De första resultaten från integrationen DTA i efterfrågemodellen för Stockholmsregionen visar att även utan systematisk kalibrering är modellresultaten i paritet med observerad trafikflöden och restider. Experimentresultaten tyder inte på någon slående skillnad mellan att använda makroskopisk eller mikroskopisk nätutläggning. Restidsvinst är ofta är den enda nyttan som ingår i nyttokalkylen för kollektivtrafikinvesteringar, men i visa fall är det befogat att använda viktade tidsvärden beroende på förhållandet belastning / kapacitet. Att inte modellera dynamiska trängseleffekter kan dock leda till påtagbar underskattning av nyttorna i projekt som primärt handlar om kapacitetshöjning snarare än restidsförkortning. Nyttan av små operationella åtgärder ska inte underskattas. Dessa åtgärder är oftast relativt billiga jämfört med investeringar i ny transportinfrastruktur och stora sociala nyttor kan därför åstadkommas.
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B2B kunders beteende vid inköp av tjänsterEkqvist, Isak, Meuller, Gustaf January 2022 (has links)
No description available.
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Identifying patterns of pedestrian accidents of different severity levels in Sweden / Statistisk mönsteridentifikation i fotgängarolyckor av olika svårighetsgrad i SverigeShi, Chengxiang January 2018 (has links)
Sweden is one of the leading countries in traffic safety, but pedestrians are vulnerable compared to other road users. “Vision zero” mission, which means no fatal or serious injury in road traffic system, has been the target of Sweden since 1997. As a result, more efforts should be put to reduce pedestrian accidents. The aim of this study is to contribute to the knowledge on reducing the number of pedestrian accidents of different severity levels in Sweden. First, this study found patterns on Swedish pedestrian accidents involving fatal, serious and moderate injuries by using same variables, then compared identified patterns corresponding to different severity levels. Then, additional patterns of pedestrian accidents involving fatal and serious injuries were assessed by adding additional variables in the clustering analysis. Finally, Swedish-oriented preventive measures were recommended based on the hypotheses on each identified patterns in a systematic way, which gave reference to policy makers in Sweden on the most urgent problems in pedestrian safety. Self-organizing map (SOM) with batch mode was applied in this study for clustering analysis, which has advantages on identifying patterns on pedestrian accidents compared to other methods, including classical linear algorithms and other unsupervised clustering algorithms (hierarchal clustering, k-means clustering and SOM with incremental mode). In addition, a specific set of assessment criteria for clustering solutions was proposed in terms of quality, stability and interpretability. According to the results of clustering solutions, falling was the main reason for serious injuries while collision with vehicles was the main reason for fatal injuries. Middle-aged and old people tended to hurt limbs when falling while children and young males tended to hurt heads. Old people might be vulnerable during daily life or within friendly traffic environment. Potential risk included outdoor activities, careless people during winter and weekend or summer night parties. Lastly, preventive measure could be combined across accidents of different severity levels, since patterns for fatal injuries were partly the same as those for non-fatal-injuries.
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