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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Implementation analysis of an information sharing system within the Supply Chain

Han, Zhicheng, Shao, Yining January 2022 (has links)
Purpose - The purpose of this paper is to help third-party logistics providers solve the difficulties in implementing a new system for their information related operations. To fulfill this purpose, three research question have been made: 1. What makes the implementation of the information system difficult for third-party logistics providers? 2. What facilitates service transfer/implementation of the information system? 3. What are the guidelines for a successful implementation of an information system for a third-party logistics provider? Method - A case study was conducted with a Swedish freight forwarder company with global presences where empirical data was collected through interviews and document analyses to fulfill the purpose of the paper. Furthermore, to make a theoretical support for the findings, a literature review was carried out. The empirical data and the result of literature review was being compared and analyzed to answer research questions. Findings - The finding has been made in the order of establishing guidelines for third-party logistics providers, especially small-to-medium size enterprises, to make a successful as well as smooth implementation of a new system for information-related operations with the empirical data and literature review result as support. To begin with, a thorough analysis was made upon the characters of the implementation which will address the difficulties. The findings are mainly related to the processes of the implementation as well as the characters of third-party logistics providers that can cause the downforce. Then, since a better understanding of the initiation of the motivation for the organizations to make the implementation can help to make scientific and thorough guidelines, the findings of which will be presented. Lastly, all the data and analysis will be used to make guidelines for the organization regarding the implementation of a new system for their information-related operations. Implications - Different studies within the areas related to the study have been made and the paper has made certain contributions to view them in a different perspective by conducting the study on a TPL company. Additionally, the study suggests that the findings have been conducted to solve one specific case which can be broadly used with the consideration of historical factors as well as customer alignment. Limitations - This study focuses specifically on a case in Sweden. Generalization has been limited due to several variables: national differences, company size and transport services, etc. In addition, the third-party logistics industry has changed rapidly and the subsequent research also has a time limit that the author could not predict. Keywords Supply chain, Third party logistics, logistics, information flow, implementation, IT service management
82

Transporteffektivitet och Kundnöjdhet Inom Last Mile Deliveries / Transport Efficiency and Customer Satisfaction in Last Mile Deliveries

Strand, Linnea, Nilsson, Tilda January 2023 (has links)
No description available.
83

Roadblocks to Implement Electric Freight Transports : Challenges for Commercial Vehicle Manufacturers and Hauliers

Gutiérrez Chiriboga, Jorge January 2024 (has links)
The freight transport industry is crucial for the global economy and a key element of all supply chains and logistics systems. The demand for freight is expected to more than double over the next three decades. Freight transport’s externalities and negative impact on the environment have been highlighted in previous research and reports. At the same time, the latest IPCC (2023) report highlights the urgency to dramatically cut emissions to mitigate the effects on climate change caused by human actions, which also relates to freight transport, which in essence is a result of the design and management of supply chains.   A way of reducing GHG emissions from logistics operations is to implement a variety of environmentally friendly strategies, processes, and activities designed to minimize the environmental impact of such operations. Switching to vehicles powered by zero-emission and non-pollutant technology is one of the proposed strategies to reduce the environmental impact of logistics operations.     Electromobility is foreseen to become one of the main pathways to decarbonize supply chains and logistics operations. However, the transition to electromobility entails that many actors in the supply chain are affected. Two important actors in the transition are the Commercial Vehicle Manufacturers (CVMs), as technology providers, and the hauliers, as technology adopters. The implementation of Heavy-duty Battery Electric Vehicles (HBEVs) in rod freight transport entails that, as technology providers, and the hauliers, as technology adopters, are exposed to a range of challenges   The purpose of the thesis is to describe and explain the challenges of implementing BEVs among Commercial Vehicle Manufacturers (CVMs) and Hauliers. This thesis targets the intersection of electromobility and supply chain management and aims to contribute to the body of research on green logistics by investigating managerial and business-related aspects of the implementation of HBEVs in road freight transports and to shed light on the subject to practitioners outside academia.    The research has been performed through literature reviews and case studies. The case studies include interviews, document studies and observations from two commercial vehicle manufacturers (of which one is a main case and one is a reference case), and eight haulier companies.   The research reveals that the challenges for both CVMs and hauliers relate to Technology, Finance, Market, Organization and Policy. Further, the challenges take different shape depending on the actor’s perspective, for example, a technology-related challenge for the CVMs such as battery capacity, translates to a technology-related challenge for the hauliers in terms of limited range.    Finally, the challenges can be interrelated and might have a reinforcing effect in many cases, which inhibits, even further, the transition to electrified freight transports. For instance, challenges related to technology have a direct impact on operations and finance. The limited range of HBEVs – a technology challenge – results in a less flexible freight vehicle, that requires a more careful planning from the hauliers’ side – operational challenge. The loss of operational flexibility entails that it’s more difficult for the hauliers to accept unplanned transport assignments from transport buyers, which has a direct impact on the haulier’s earning capacity – a financial challenge. / Transportindustrin är avgörande för den globala ekonomin och en viktig del i alla leveranskedjor och logistiksystem. Efterfrågan på godstransporter förväntas mer än fördubblas över de närmaste tre decennierna. Godstransporternas negativa inverkan på miljön har lyfts fram i tidigare forskning och rapporter. Samtidigt understryker den senaste IPCC-rapporten (2023) behovet av att drastiskt minska utsläppen för att mildra effekterna av klimatförändringar som orsakas av mänskliga handlingar. Det gäller även godstransporter, som i huvudsak är ett resultat av utformningen och hanteringen av leveranskedjor.    Ett sätt att minska koldioxidutsläpp från logistikverksamhet är att implementera strategier, processer och aktiviteter utformade för att minimera miljöpåverkan av denna typ av verksamhet. Att övergå till nollutsläppsfordon är en av de föreslagna strategierna för att minska den miljömässiga påverkan av logistikverksamheten.    Elektrifiering förutspås bli ett av huvudspåren för att minska koldioxidutsläpp från leveranskedjor och logistikverksamhet. Emellertid innebär övergången till elektrifiering att många aktörer i leveranskedjan påverkas. Två viktiga aktörer i övergången är fordonstillverkarna (CVMs, engelsk förkortning), som teknikleverantörer, samt åkerierna, som teknikanvändare. Implementeringen av tunga batteridrivna elfordon (HBEVs, engelsk förkortning) i godstransporter innebär att fordonstillverkare och åkerier står inför en rad utmaningar.    Syfte med denna avhandling är att beskriva och förklara utmaningarna med att implementera tunga batteridrivna elfordon för fordonstillverkare och åkerier. Avhandlingen fokuserar på skärningspunkten mellan elektromobilitet och Supply Chain Management, och bidrar till forskningen om grön logistik genom att undersöka lednings- och affärsrelaterade aspekter av implementeringen av tunga batteridrivna elfordon, samt att belysa ämnet för praktiker utanför den akademiska världen.   Forskningen har genomförts genom litteraturstudier och fallstudier. Fallstudierna inkluderar intervjuer, dokumentstudier och observationer från två tillverkare av kommersiella fordon (varav en är ett huvudfall och en är ett referensfall) och åtta åkeriföretag. Forskningen visar att utmaningarna för både fordonstillverkare och åkerier rör teknik, finansiering, marknad, organisation och policy. Utmaningarna tar sig olika uttryck beroende på aktörens perspektiv, till exempel, en teknikrelaterad utmaning för fordonstillverkare, såsom batterikapacitet, blir en teknikrelaterad utmaning för åkerierna i form av begränsad räckvidd.    Slutligen kan utmaningarna vara sammanlänkade och, i många fall, ha en förstärkande effekt vilket ytterligare hämmar övergången till elektrifierade godstransporter. Bland annat har teknikrelaterade utmaningar en direkt inverkan på drift och ekonomi. Exempelvis resulterar den begränsade räckvidden - en teknikrelaterad utmaning - i ett mindre flexibelt fordon, vilket kräver en noggrannare planering från åkeriernas sida - en operativ utmaning. Mindre operativ flexibilitet innebär att det blir svårare för åkerierna att acceptera oplanerade transportuppdrag från transportköpare, vilket har en direkt inverkan på åkeriets intäktskapacitet - en finansiell utmaning.
84

The impact of climate change on aviation in Sweden / Klimatförändringens påverkan på flyg inom Sverige

Al-Nazary, Ashur, Youssef, Randy January 2024 (has links)
<p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
85

Building Resilience in the Global Supply Chain : Sustainable Strategies to Mitigate the Container Shortage Experienced

Yi, Xianglong January 2022 (has links)
No description available.
86

Two papers on consistent estimation of a route choice model and link speed using sparse GPS data

Fadaei Oshyani, Masoud January 2013 (has links)
Global Positioning System and nomad devices are increasingly used to provide data from individuals in urban traffic networks. In these two papers we focus on consistent estimators of a route choice model and link speed. In many different applications, it is important to predict the continuation of an observed path, and also, given sparse data, predict where the individual (or vehicle) has been. Estimating the perceived cost functions is a difficult statistical estimation problem, for different reasons. First, the choice set is typically very large. Second, it may be important to take into account the correlation between the (generalized) costs of different routes, and thus allow for realistic substitution patterns. Third, due to technical or privacy considerations, the data may be temporally and spatially sparse, with only partially observed paths. Finally, the position of vehicles may have measurement errors. We address all these problems using an indirect inference (II) approach. We demonstrate the feasibility of the proposed estimator in a model with random link costs, allowing for a natural correlation structure across paths, where the full choice set is considered. In the second paper, we develop an estimator for the mean speed and travel time based on indirect inference when the data are spatially and temporally sparse. With sparse data, the full path of vehicles are not observed, which is typically addressed using map matching techniques. First, we show how speed can be estimated using an auxiliary model which includes map matching and a model of route choice. Next, we further develop the estimator and show how both speed and the route choice model can be jointly estimated by using iteration between an II estimator of speed and the II estimator of the route choice model (developed in Paper I). Monte Carlo evidence is provided which demonstrates that the estimator is able to accurately estimate both speed and parameters of the route choice model. / <p>QC 20130521</p>
87

Regional Intermodal Transport Systems : Analysis and Case Study in the Stockholm-Mälaren Region

Kordnejad, Behzad January 2013 (has links)
The global trend of urbanization is evident and also valid in Sweden and for the Stockholm-Mälaren region, also referred to as the Mälaren valley, a region consisting of metropolitan Stockholm and areas around the lake of Mälaren. In this context, efficient urban freight transportation has emerged as essential for sustainable development of urban areas. Geographic regions are being expanded due to the fact that rapid transport options have expanded the range of action of people and businesses. Metropolitan regions require freight transports that are often categorized by an inflow of consumables and an outflow of waste and recyclable material. Within urban areas there are ports, terminals and storage facilities that require incoming and outgoing transport. Altogether, these shipments have led to increased congestion on the road network within urban areas, which is a contributing factor to why a shift to intermodal land transports have been advocated both in Europe and in Sweden, thus encouraging more freight to be moved from road to rail. Another contributing factor is the relatively low impact on the environment generated by rail transportation. Efficient use of resources and low emissions of greenhouse gases are factors that are in favor of the train as a transport mode. Furthermore, conventional rail freight is commonly competitive on long distances and in end-point relations between two nodes. However, an intermodal liner train, as a transport system for freight differs from conventional rail freight transport systems, as it similar to a passenger train makes stops along the route for loading and unloading. Due to the stops made at intermediate stations it enables the coverage of a larger market area. For regional or inter-regional relations, the concept has the potential of reducing drayage by truck to and from intermodal terminals and to make rail freight competitive also over medium and short distances. The main aim of this thesis project has been to analyze under which conditions a combined transport system with the railway as a base can be implemented in the Stockholm-Mälaren region. Based on a case study for a shipper distributing daily consumables in the region, the feasibility of creating a regional rail freight transport system has been evaluated. This study provides a methodology for evaluating the feasibility, regarding costs and emissions, of concepts and technologies within freight transportation chains. This has been accomplished by the development of a cost modal, Intermodal Transport Cost Model (ITCM). From the results of the case study one can conclude that a regional rail based intermodal transport system regarding costs is on the threshold of feasibility in the studied region. As for emissions, all evaluated intermodal transport chains contribute to a significant decrease in CO2 emissions compared to unimodal road haulage. The loading space utilization of the train and the transshipment cost are the most critical parameters. The latter restricting the competitiveness of intermodal services to long distances as it is not proportional to transported distance but rather to the utilization rate of resources. Hence, the concept of cost-efficient small scale (CESS) terminals is introduced in this study. A main prerequisite in order to make the intermodal liner train efficient is a stable and balanced flow of goods with optimized loading space utilization along the route. As the objective is to consolidate small flows, imbalances along the route will constitute an obstacle for the liner train to be competitive. Thus regarding loading space utilization it is necessary to consolidate other freight flows in the train in order to achieve high loading space utilization and a balanced flow along the route. The third parameter which is critical for the results are the fuel prices, where a sensitivity analysis of the results shows that if diesel prices would increase so would the feasibility of the intermodal option. The same is also valid for train length increase as long as the loading space utilization is maintained. The results of the feasibility study indicate that the evaluated transshipment technologies are closing the gap for intermodal transport to unimodal road haulage regarding transport cost over short- and medium distances and that they contribute to a substantial reduction of CO2 emissions. However, it is essential that also the transport quality is ensured, especially regarding reliability and punctuality. Thus a demonstration project is recommended as these aspects require operational testing. This is particularly crucial regarding novel transshipment technologies. / <p>QC 20130530</p> / Regional kombitransportsystem i Mälardalen
88

Simulation based evaluation of flexible transit

Leffler, 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>
89

Simulation of rail traffic : applications with timetable construction and delay modelling

Sipilä, Hans January 2012 (has links)
This thesis covers both applications where simulation is used on parts of the Swedish rail networks and running time calculations for future high-speed trains with top speed improvements on existing lines. Calculations are part of a subproject within the Green Train research program (Gröna tåget). Higher speeds are possible with increased cant and cant deficiency in curves. Data for circular curve radii is used on existing lines combined with information on decided and on-going upgrades. Calculation of static speed profiles is made for a set of cant and cant deficiency values. Different train characteristics are used regarding top speed, starting acceleration and power to ton ratio. Running time calculations are made for these different train characteristics with the fictive speed profiles. In addition, different stopping patterns are applied. Results are presented together with running times for two reference train types, one with carbody tilting and one without. It is clear that carbody tilting, allowing a higher cant deficiency, is important on many of the existing lines considering achieved running times. The benefit of tilting is marginal on newly built and future lines designed with large curve radii. However, on many of the existing lines the over 20 year old reference train with carbody tilting achieves shorter running times compared to a future train without tilt but with higher top speed. The work presented here has contributed with input to other projects and applications within the research program. Simulation in RailSys is used to evaluate on-time performance for high-speed trains, between Stockholm and Göteborg in Sweden, and changes in timetable allowances and buffer times with respect to other trains. Results show that ontime performance can be improved with increased allowances or buffer times. In the case with increased buffers, other trains are pushed in the timetable with the intention of obtaining at least five minutes at critical places (e.g. conflicting train paths at stations) and as separation on line sections. On-time performance is evaluated both on aggregated (group) level and for trains individually. Some of the trains benefit significantly from the applied measures. Prior to a simulation some of the delays have to be defined. This includes dwell extensions and entry delays, i.e. extended exchange times at stations and delayed origin station departures inside or at the network border. Evaluation of observed data give insight on the performance of a real network. However, separating primary (exogenous) and secondary (knock-on) delays is not straightforward. Typically the probabilities and levels of primary delays are defined as input, thus secondary delays are created in the simulations. Although some classification of delays exist in observed data, it is not sufficient without further assumptions and preparation. A method for estimating primary running time extensions is presented and applied on a real timetable between Katrineholm and Hässleholm in Sweden. The approach consist of creating distributions based on deviations from scheduled running time. Since this represent total outcome, i.e. both primary and knock-on delays are included, the distributions are reduced by a certain percentage and applied in the simulations. Reduction is done in four steps, separately for passenger and freight trains. Root mean square error (RMSE) is used for comparing mean and standard deviation values between simulated and observed data. Results show that a reasonably good fit can be obtained. Freight services show a higher variation than passenger train evaluation groups. Some explanations for this are difficulties in capturing the variations in train weights and speeds and absence of shunting operations in the model. In reality, freight trains can also frequently depart ahead of schedule and this effect is not captured in the simulations. However, focus is mostly on passenger trains and their on-time performance. If a good enough agreement and operational behaviour is achieved for them, a lower agreement for freight trains may be accepted. / QC 20120611
90

Congested railways : influence of infrastructure and timetable properties on delay propagation

Lindfeldt, Anders January 2012 (has links)
In this thesis the symptoms and underlying behaviour of congestion on railways are analysed and discussed. As well as in many other countries, Sweden faces increasing demand for transport. To meet this new demand, railways play an important role. Today, the capacity of the Swedish rail network is not upgraded at the speed necessary to keep up with the increase in traffic demand. The sensitivity of the railway system rises as the capacity utilisation increases. At some point the marginal gain of operating one extra train is lower than the costs in term of increased sensitivity to delay, i.e. maximum capacity has been reached. Two methodologies are employed in this thesis to analyse capacity. The first uses real data from the Swedish rail network, train operation and delays to analyse how different factors influence available capacity and delay creation. Several useful key performance indicators are defined to describe capacity influencing properties of the infrastructure and the rail traffic. The rail network is divided into subsections for which the indicators have been estimated. This makes it possible to discern their different characteristics and identify potential weaknesses.  The second approach employs the railway simulation tool RailSys in extensive simulation experiments. This methodology is used to analyse the characteristics of double track operation. Simulation of several hundred scenarios are conducted to analyse the influence of traffic density, timetable speed heterogeneity, primary delays and inter-station distance on secondary delays and used timetable allowance. The analysis gives an in-depth understanding of the mechanisms behind the performance of a double track. / QC 20120614

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