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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.
21

Hybrid simulation and optimization approach for green intermodal transportation problem with travel time uncertainty

Hrusovsky, Martin, Demir, Emrah, Jammernegg, Werner, van Woensel, Tom 09 1900 (has links) (PDF)
The increasing volumes of road transportation contribute to congestion on road, which leads to delays and other negative impacts on the reliability of transportation. Moreover, transportation is one of the main contributors to the growth of carbon dioxide equivalent emissions, where the impact of road transportation is significant. Therefore, governmental organizations and private commercial companies are looking for greener transportation solutions to eliminate the negative externalities of road transportation. In this paper, we present a novel solution framework to support the operational-level decisions for intermodal transportation networks using a combination of an optimization model and simulation. The simulation model includes stochastic elements in form of uncertain travel times, whereas the optimization model represents a deterministic and linear multi-commodity service network design formulation. The intermodal transportation plan can be optimized according to different objectives, including costs, time and CO2e emissions. The proposed approach is successfully implemented to real-life scenarios where differences in transportation plans for alternative objectives are presented. The solutions for transportation networks with up to 250 services and 20 orders show that the approach is capable of delivering reliable solutions and identifying possible disruptions and alternatives for adapting the unreliable transportation plans.
22

Análise das incertezas dos processos de chegadas na operação de um terminal intermodal / not available

Santos, Sérgio Ricardo Chisté 13 April 1998 (has links)
Os terminais intermodais operam com modos de transporte com diferentes capacidades, e podem constituir pontos de gargalo no sistema de transporte. O objetivo deste trabalho é avaliar a influência que as incertezas nos processos de chegadas causam no desempenho e no dimensionamento do terminal. Na investigação de hipótese adotou-se o método de simular as condições operacionais de um terminal onde existem dados da operação atual. Para isto, coletaram-se dados referentes aos processos de chegadas de barcaças e vagões a um terminal intermodal fluvial localizado na hidrovia Tietê-Paraná. A operação do terminal foi simulada utilizando o software ARENA, representando o período de 150 dias, correspondente a safra de soja. Concluiu-se que a variação estocástica nos processos de chegadas de barcaças e vagões possuem forte influência no desempenho do terminal, e que uma melhoria na gerência operacional desses processos pode representar ganhos consideráveis para os agentes envolvidos. / The difference in the arrival flow of cargo carried in vehicles of different loading capacities usually transform intermodal terminals into bottlenecks of the transportation system. The aim of this study is to evaluate the influence of the uncertainties in the sizing of an intermodal terminal. Data obtained from the observation of arrival process of barges and trains to a grain intermodal terminal located at Tietê-Paraná inland waterway is used in a case study. The operation of the terminal during the 150-day harvest period of oy beans is simulated using the ARENA software. It is concluded that the stochastic variation in the arrival process of bargers and trains have strong influence on the terminal performance, and that better management of these processes would provide considerable gains to all operation in the partners.
23

Análise das incertezas dos processos de chegadas na operação de um terminal intermodal / not available

Sérgio Ricardo Chisté Santos 13 April 1998 (has links)
Os terminais intermodais operam com modos de transporte com diferentes capacidades, e podem constituir pontos de gargalo no sistema de transporte. O objetivo deste trabalho é avaliar a influência que as incertezas nos processos de chegadas causam no desempenho e no dimensionamento do terminal. Na investigação de hipótese adotou-se o método de simular as condições operacionais de um terminal onde existem dados da operação atual. Para isto, coletaram-se dados referentes aos processos de chegadas de barcaças e vagões a um terminal intermodal fluvial localizado na hidrovia Tietê-Paraná. A operação do terminal foi simulada utilizando o software ARENA, representando o período de 150 dias, correspondente a safra de soja. Concluiu-se que a variação estocástica nos processos de chegadas de barcaças e vagões possuem forte influência no desempenho do terminal, e que uma melhoria na gerência operacional desses processos pode representar ganhos consideráveis para os agentes envolvidos. / The difference in the arrival flow of cargo carried in vehicles of different loading capacities usually transform intermodal terminals into bottlenecks of the transportation system. The aim of this study is to evaluate the influence of the uncertainties in the sizing of an intermodal terminal. Data obtained from the observation of arrival process of barges and trains to a grain intermodal terminal located at Tietê-Paraná inland waterway is used in a case study. The operation of the terminal during the 150-day harvest period of oy beans is simulated using the ARENA software. It is concluded that the stochastic variation in the arrival process of bargers and trains have strong influence on the terminal performance, and that better management of these processes would provide considerable gains to all operation in the partners.
24

Aerodynamic Drag On Intermodal Rail Cars

Kinghorn, Philip Donovan 01 June 2017 (has links)
The freight rail industry is essential to the US infrastructure and there is significant motivation to improve its efficiency. The aerodynamic drag associated with transport of commodities by rail is becoming increasingly important as the cost of diesel fuel increases. For intermodal railcars a significant amount of aerodynamic drag is a result of the large distance between containers that often occurs and the resulting pressure drag resulting from the separated flow that results due to their non-streamlined shape. This thesis reports on research that has been done to characterize the aerodynamic drag on intermodal train builds and allow their builds to be optimized for fuel efficiency. Data was obtained through wind tunnel testing of G-scale (1/29) models. Drag on these models was measured using a system of isolated load cell balances and the wind tunnel speed was varied from 20 to 100 mph. Several common intermodal scenarios were explored and the aerodynamic drag for each was characterized. These scenarios were the partial loading of containers on rail cars, the influence of the gap between containers, the use of a streamlined container near the front of the train, and the inclusion of semi-trailers on railcars. For each case multiple build configurations were tested and the drag results were compared to determine the optimal build for each scenario.
25

Development of dry ports in Småland, Sweden : Comparing the cases of Nässjö and Vaggeryd

Haak, Frans Willem Gerard, Tamosaityte, Dainora January 2012 (has links)
Problem: Due to several changes in the market, economy, industry and the environment there was an increasing trend in emerging dry ports/inland terminals throughout Sweden. A dry port is still a young term in the transportation field gaining more popularity and attention. The gap in literature was found that the dynamics of dry port evolution is not yet explored. Thus, the development of the layout, services offered and involved actors of dry ports in Småland, Sweden have to be studied. Purpose:  The purpose for this report seeks to reveal how dry ports have evolved from establishment, in the area around Jönköping, and to discover in what form the dry ports can operate and compete. The study was based on the dynamics of three elements: layout, value added services and networks. Theory:  In the theoretical research the dry port concept is described. Due to the variety of descriptions, authors formed a definition for the thesis to clarify the content. Further, the literature analysis contained the characteristics, classifications and reasons of development as well as involved actors, advantages and disadvantages, location, layout, design and performance measurements. Method: The case study method was chosen to cover the identified gap. This qualitative study with semi-structured interviews conducted face-to-face and by telephone was accomplished with fourteen experts. If the authors faced problems regarding phone interviewees, open questions were prepared and sent to the respondent via email. The data gathering phase was followed by the analysis after which the conclusions were drawn. Conclusion:   The thesis proves that the development of dry ports is affected by a large number of internal and external factors. Terminals need to execute a thorough analysis of the market and the location in which they plan to operate. Therefore, the market has to be analysed continuously in order to keep improving their networks and value added services. Furthermore, the layout has to be adjusted for the changes and measurements have to be performed in order to increase the efficiency.
26

Developing a container freight information system to understand container truck traffic in inland port cities

Rempel, Garreth 01 September 2011 (has links)
Container freight is an important component of the transportation system yet there is little understanding about this issue. This research develops an information system to assist transportation engineers and planners understand container freight transportation in the Canadian Prairie Region. The research conducts a transportation systems analysis to provide information about regional transportation, demand, and flow characteristics of container freight. It also designs, develops, and applies a container truck model to provide information about urban container truck traffic activity. The analysis and model reveal issues that should be considered in defining, evaluating, and choosing among alternative options to improve urban container freight transportation. The transportation systems analysis reveals the following issues affecting regional container freight. The Panama Canal expansion has the capability of altering container freight using the mini land bridge between West and East coast ports although the Port of Prince Rupert is emerging as a legitimate option to the Panama Canal. Railroads are developing integrated logistics centres which often involve relocating intermodal terminals and introducing major container generators to a city. Railroads are operating longer container trains and making fewer stops at prairie cities; however, these cities are developing inland ports to attract international freight. This research produces the first urban container truck traffic model to help overcome insufficient data and information in this area. It comprises defining a container truck network, acquiring container truck traffic data, and estimating container truck traffic volumes. The model is applied to the City of Winnipeg although the following issues are expected to be similar in other prairie cities. The research reveals issues regarding the temporal, spatial distribution, and physical characteristics of container trucks. Overall, about 13 percent of articulated trucks carry containers; however, corridors with high articulated truck volumes do not necessarily have high container truck volumes. Weekend articulated truck traffic volumes are nearly one-quarter of weekday volumes whereas Sunday container truck volumes are similar to weekday volumes. Container truck volumes peak during the midday while articulated truck volumes exhibit an a.m. and p.m. peak. The split between tridem and tandem axle semitrailers is 80/20 for container trucks.
27

Developing a container freight information system to understand container truck traffic in inland port cities

Rempel, Garreth 01 September 2011 (has links)
Container freight is an important component of the transportation system yet there is little understanding about this issue. This research develops an information system to assist transportation engineers and planners understand container freight transportation in the Canadian Prairie Region. The research conducts a transportation systems analysis to provide information about regional transportation, demand, and flow characteristics of container freight. It also designs, develops, and applies a container truck model to provide information about urban container truck traffic activity. The analysis and model reveal issues that should be considered in defining, evaluating, and choosing among alternative options to improve urban container freight transportation. The transportation systems analysis reveals the following issues affecting regional container freight. The Panama Canal expansion has the capability of altering container freight using the mini land bridge between West and East coast ports although the Port of Prince Rupert is emerging as a legitimate option to the Panama Canal. Railroads are developing integrated logistics centres which often involve relocating intermodal terminals and introducing major container generators to a city. Railroads are operating longer container trains and making fewer stops at prairie cities; however, these cities are developing inland ports to attract international freight. This research produces the first urban container truck traffic model to help overcome insufficient data and information in this area. It comprises defining a container truck network, acquiring container truck traffic data, and estimating container truck traffic volumes. The model is applied to the City of Winnipeg although the following issues are expected to be similar in other prairie cities. The research reveals issues regarding the temporal, spatial distribution, and physical characteristics of container trucks. Overall, about 13 percent of articulated trucks carry containers; however, corridors with high articulated truck volumes do not necessarily have high container truck volumes. Weekend articulated truck traffic volumes are nearly one-quarter of weekday volumes whereas Sunday container truck volumes are similar to weekday volumes. Container truck volumes peak during the midday while articulated truck volumes exhibit an a.m. and p.m. peak. The split between tridem and tandem axle semitrailers is 80/20 for container trucks.
28

Audiovisualitet : En diskursanalys om det nya gamla

Fernström, Torbjörn January 2017 (has links)
Syftet med denna diskursanalys är att bidra med kunskap om hur audiovisualitet har setts på och förändrats från 1936 fram till 2008. Detta undersöks utifrån sex stycken texter som är uppsatsens empiri. Huvudfrågan i denna uppsats begrundar huruvida dessa skillnader finns och hur de kan relateras till varandra. Analysprocessen utgår från socialkonstruktivism som teori för att kunna förstå de skillnader som undersöks. Resultatet av denna undersökning visar att det finns små skillnader i hur vissa relaterade begrepp används, detta tas vidare upp i diskussionsdelen där det även diskuteras hur förutsättningar för tidigare och framtida diskurser om audiovisualitet ser ut. Förslag till fortsatt forskning är en liknande studie med fokus på moderna texter för att se om det finns samtida skillnader och även om resultatet utifrån det skiljer sig från det i denna undersökning.
29

The development of an uninterruptible traceability system for intermodal transport

Hood, James January 2016 (has links)
The focus of this research is in the area of Remote Condition Monitoring (RCM) for use within intermodal transport and logistics industries. For many years the intermodal transport industry has utilised these RCM systems that have in built flaws due to the subsystems they use.
30

Intermodální přeprava se zaměřením na dovoz z Číny do České republiky / Intermodal transport with a focus on import from China to the Czech republic

Zuzánková, Aneta January 2011 (has links)
The diploma thesis characterizes intermodal transport and individual systems which it uses. It also desribes the current development of transport and its individual sectors. The diploma thesis also outlines the issue of external economic relations and foreign trade between China and the Czech republic. I picked up and characterized the representatives of shipping carriers and intermodal carriers. In the last part of the thesis I described the specific case of import of three containers from a Chinese shipper to a Czech consignee.

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