• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 51
  • 25
  • 22
  • 7
  • 5
  • 4
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 131
  • 131
  • 44
  • 37
  • 22
  • 20
  • 17
  • 16
  • 15
  • 13
  • 13
  • 13
  • 11
  • 10
  • 10
  • 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.
11

Carrier selection criteria for Scandinavian domestic road transport : A study of the competition between Scandinavian and Eastern European hauliers in a scenario without restrictions on cabotage

Tillman, Peter January 2012 (has links)
The European Commission has for some time indicated a desire to remove the remaining restrictions on cabotage. Such liberalization is expected to result in significant changes on some domestic road transport markets. The Scandinavian markets are among these and the local hauilers fear that the lower wages of Easter European hauliers will leave them out of business. In this thesis a scenario of full cabotage liberalization is assumed. Representatives from associations with interest within the Scandinavian road transport markets has been approached with a qualitative survey on carrier selection criteria. Respondents are asked to determine the importance of the criteria, as well as the relevance to the competition between Scandinavian and Eastern European hauliers. Finally they are asked to assess whether the advantage of each criterion lies with Scandinavian or Eastern European hauliers. The qualitative orientation of the survey is achieved though justification and follow up questions. Reliability of pickups and deliveries is still regarded the most important criteria. Also competitive prices received a high rating. It is concluded that the significant price difference between Scandinavian and Eastern European hauliers will benefit Eastern European hauliers considerably in the competition for the simple “from A to B” shipments. For more complicated shipments, entailing a higher level of service, communication and supply chain integration, the local hauliers are expected to stand their ground.
12

Roteirização de veículos com janelas de tempo utilizando algoritmo genético. / Vehicle routing with time windows using generic algorithm.

Caio Domingues Reina 13 April 2012 (has links)
O componente de planejamento faz parte do projeto de desenvolvimento dos veículos autônomos, e é responsável por gerar rotas para o sistema como um todo. Em aplicações em que o veículo deve visitar pontos em intervalos de tempo pré-determinados, o componente de planejamento se enquadra em um problema de roteirização conhecido da literatura, denominado problema de roteirização de veículos com janelas de tempo. Tal problema é uma generalização do problema clássico de roteirização de veículos classificado no grupo de problemas NP-Hard. Esse trabalho apresenta uma proposta de solução para o problema baseada na metaheurística algoritmo genético. Os cromossomos foram representados pela ordem de atendimento dos clientes sem delimitadores de rota. Para quebrar os cromossomos em rotas, foi utilizado um procedimento adaptado baseado em Prins (2004). A população inicial se constitui por uma parte construída com cromossomos criados aleatoriamente e outra parte construída através da heurística de inserção I1 de Solomon (1987), com quatro formas diferentes de inserir o primeiro cliente de cada rota. Na fase de recombinação, foram utilizados quatro tipos de crossover: uniforme, dois pontos, heurístico e PMX, e um operador de mutação baseado em uma busca heurística. A cada geração foram aplicados princípios de elitismo e pós-otimização utilizando a heurística -interchange de Osman (1993). O algoritmo foi testado nos conjuntos C1, C2, R1, R2, RC1 e RC2 de Solomon (1987) e os resultados foram comparados com os melhores resultados encontrados na literatura. / The planning component is a part of autonomous vehicle development project and it is responsible to generate routes for the system as a whole. In applications which vehicle must to visit way points at predetermined intervals of time, the planning component fits into a routing problem known in the literature called routing problem with time windows. This problem is a generalization of the classical vehicle routing problem classified in the group of NP- Hard problems. This thesis presents a solution proposal to problem based on genetic algorithm metaheuristic. Chromosomes were represented by the order of serving customers without delimiters route. To split the chromosomes on routes, it is used a procedure adapted based on Prins (2004). The initial population is constituted by two parts: one with randomly created chromosomes and another constructed through the insertion heuristic I1 of Solomon (1987), with four different ways of insertion of the first customer of each route. In the recombination step, four types of crossover were used: uniform, two points, heuristic, and PMX, and a mutation operator based on heuristic search. In each generation it is applied principles of elitism and postoptimization using the -interchange heuristic of Osman (1993). The algorithm was tested on the sets C1, C2, R1, R2, RC1 and RC2 of Solomon (1987) and the results were compared with the best results found in the literature.
13

Accident risk and environmental assessment : development of an assessment guideline with examination in northern Scandinavia /

Lundkvist, Markus, January 2005 (has links)
Diss. Uppsala : Uppsala universitet, 2005.
14

The use of tax-based fiscal measures in the legal response to climate change / Louis Stefanus van der Walt

Van der Walt, Louis Stefanus January 2010 (has links)
Climate change is currently one of the most pressing environmental concerns globally and in South Africa. South Africa is especially vulnerable to the effects of climate change because of the country’s socio-economic context, water scarcity, unique geography and climate sensitive biodiversity. South Africa’s road transport and energy sectors are among others major contributors to climate change. The traditional command and control measures designed to mitigate climate change in South Africa’s road transport and energy sectors do not suffice on their own, there is a need for tax-based fiscal measures to assist in mitigating climate change in these sectors. Tax-based fiscal measures offer certain unique climate change mitigation capabilities, therefore numerous tax-based fiscal measures are already in place in South Africa’s road transport and energy sectors. The development of new taxbased fiscal measures should be encouraged and existing tax-based fiscal measures can and should be refined and extended to enhance their climate change mitigation efficacy. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2011
15

Rail transport and the economic competitiveness of South Africa : timeous delivery of goods and demurrage / Dineo Mosimo Sandra Mathabatha

Mathabatha, Dineo Mosimo Sandra January 2015 (has links)
Rail transport refers to the transportation of various commodities, goods and services traded as cargo and freight within South Africa and out of South Africa for export to the other Southern African communities (SADC region), the rest of Africa and other continents of the world. It also refers to the imports into South Africa from the regions mentioned. Competitiveness relates to a country or company’s available resources and supporting policies and regulations in place which allow them to compete and do business locally, internationally and globally while improving the country’s economy and the company’s profitability. There are different criteria that can be used to determine the level of competitiveness, depending on each company or country’s capabilities. In the past years, the progress and development of the South African rail industry has been neglected and this has resulted in the rail transportation not being used. Railway line maintenance has become a challenge and service delivery is below customer expectations. Road transport has better availability and reliability, which has led companies to prefer road transport for freight. The main objective of this study is to reach a detailed understanding of the views of freight rail transport consumers and the impact of rail transport on the economic competitiveness of South Africa. Another important objective is to present the study in a format that is easily understandable. The approach adopted for this study is quantitative and uses a survey research questionnaire which was distributed to freight rail transport customers and providers. The data collected from the questionnaire was submitted to a statistical consultant service at North-West University. The statistical consultant analysed the data using the SPSS statistics computer programme to arrive at the results presented in this study. The overall findings from this study are that companies that use roads to transport freight do so because of the unavailability and unreliability of the freight rail transport provider Transnet Freight Rail and that these companies opt for road transport because they use a ‘just in time’ (JIT) system whereby a small quantity of stock is transported continuously which Transnet Freight Rail (TFR) does not accommodate. These factors have resulted in TFR’s poor service delivery. Therefore, a market demand strategy has been initiated by TFR to improve the performance of the company. It is important to note here that freight rail transport should concentrate on improving service delivery and not only on increasing capacity. The research participants indicated that the TFR objective to move freight back to rail could be accomplished. This will lessen the burden and damage to South African roads and reduce traffic congestion and accidents caused by trucks on the roads. It will also increase employment opportunities and the country’s economic competitiveness while reducing transport costs. All these aspects will make a significant impact on the economy of the country. / MBA, North-West University, Potchefstroom Campus, 2015
16

The use of tax-based fiscal measures in the legal response to climate change / Louis Stefanus van der Walt

Van der Walt, Louis Stefanus January 2010 (has links)
Climate change is currently one of the most pressing environmental concerns globally and in South Africa. South Africa is especially vulnerable to the effects of climate change because of the country’s socio-economic context, water scarcity, unique geography and climate sensitive biodiversity. South Africa’s road transport and energy sectors are among others major contributors to climate change. The traditional command and control measures designed to mitigate climate change in South Africa’s road transport and energy sectors do not suffice on their own, there is a need for tax-based fiscal measures to assist in mitigating climate change in these sectors. Tax-based fiscal measures offer certain unique climate change mitigation capabilities, therefore numerous tax-based fiscal measures are already in place in South Africa’s road transport and energy sectors. The development of new taxbased fiscal measures should be encouraged and existing tax-based fiscal measures can and should be refined and extended to enhance their climate change mitigation efficacy. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2011
17

Rail transport and the economic competitiveness of South Africa : timeous delivery of goods and demurrage / Dineo Mosimo Sandra Mathabatha

Mathabatha, Dineo Mosimo Sandra January 2015 (has links)
Rail transport refers to the transportation of various commodities, goods and services traded as cargo and freight within South Africa and out of South Africa for export to the other Southern African communities (SADC region), the rest of Africa and other continents of the world. It also refers to the imports into South Africa from the regions mentioned. Competitiveness relates to a country or company’s available resources and supporting policies and regulations in place which allow them to compete and do business locally, internationally and globally while improving the country’s economy and the company’s profitability. There are different criteria that can be used to determine the level of competitiveness, depending on each company or country’s capabilities. In the past years, the progress and development of the South African rail industry has been neglected and this has resulted in the rail transportation not being used. Railway line maintenance has become a challenge and service delivery is below customer expectations. Road transport has better availability and reliability, which has led companies to prefer road transport for freight. The main objective of this study is to reach a detailed understanding of the views of freight rail transport consumers and the impact of rail transport on the economic competitiveness of South Africa. Another important objective is to present the study in a format that is easily understandable. The approach adopted for this study is quantitative and uses a survey research questionnaire which was distributed to freight rail transport customers and providers. The data collected from the questionnaire was submitted to a statistical consultant service at North-West University. The statistical consultant analysed the data using the SPSS statistics computer programme to arrive at the results presented in this study. The overall findings from this study are that companies that use roads to transport freight do so because of the unavailability and unreliability of the freight rail transport provider Transnet Freight Rail and that these companies opt for road transport because they use a ‘just in time’ (JIT) system whereby a small quantity of stock is transported continuously which Transnet Freight Rail (TFR) does not accommodate. These factors have resulted in TFR’s poor service delivery. Therefore, a market demand strategy has been initiated by TFR to improve the performance of the company. It is important to note here that freight rail transport should concentrate on improving service delivery and not only on increasing capacity. The research participants indicated that the TFR objective to move freight back to rail could be accomplished. This will lessen the burden and damage to South African roads and reduce traffic congestion and accidents caused by trucks on the roads. It will also increase employment opportunities and the country’s economic competitiveness while reducing transport costs. All these aspects will make a significant impact on the economy of the country. / MBA, North-West University, Potchefstroom Campus, 2015
18

Contribution of an emission trading scheme to reduce road traffic induced CO2 emissions in Austria

Link, Christoph, Stark, Juliane, Sonntag, Axel, Hössinger, Reinhard 14 July 2012 (has links) (PDF)
The Emission Trading Scheme for green house gases is a key tool of European climate protection. Including the road transport sector might be a promising strategy to limit its CO2 emissions. This could be realized within a common market (trans-sectoral trading permitted) or separated markets (trans-sectoral trading not permitted). Starting from different assumptions on emission reduction objectives, the impact of both options is analyzed using a quantitative model. Although an emission trading scheme is ecologically effective regardless of the trading model, it turns out that CO2 emissions and emission allowance prices differ strongly between both design options due to sector specific price elasticities of allowance demand. (authors' abstract)
19

Território e circulação: transporte rodoviário de carga no Brasil / Territory and circulation: road freight in Brazil

Huertas, Daniel Monteiro 26 August 2013 (has links)
O transporte rodoviário de carga é o objeto de estudo desta tese, que parte do pressuposto de que sua estruturação e organização no território brasileiro foram acompanhadas por um processo de seletividade espacial que privilegiou certos pontos e áreas em detrimento de outros, evidenciando uma rede gegráfica reveladora do uso do território. A hipótese ainda leva em conta o fato de que o transporte rodoviário de carga, a partir de meados dos anos 1990, inseriu-se em um momento de transformações estruturais e conjunturais condizentes com as variáveis do período histórico atual, consequência da globalização perversa que avassala o mundo com eventos hegemônicos que servem aos desígnios do capital. Pretendemos demonstrar que o transporte rodoviário de carga cria uma topologia própria, cuja configuração territorial é composta por linhas e nodais que em seu conjunto modelam uma rede geográfica capaz de expressar a interação e dissociação geográfica dos lugares intrínseca à formação socioespacial brasileira. Acreditamos que este caminho, baseado metodologicamente na divisão territorial do trabalho, nos circuitos da economia urbana e nos circuitos espaciais produtivos, proporcione uma leitura bastante interessante no que diz respeito ao uso diferenciado do território, evidenciando com mais força a hierarquia dos lugares e a correlação de forças entre os agentes que operam o transporte rodoviário de carga. Para corroborar esta ideia identificamos os nodais tidos como a expressão máxima da seletividade espacial do transporte rodoviário de carga e divididos em quatro níveis que, ao concentrar uma série de atributos geográficos produtores de funcionalidades, hierarquias e polarizações, ajudam a explicar a rede geográfica em questão. O ponto de partida é o que propomos chamar de polígono paulista, um nodal primário de força polarizadora única, responsável pela determinação das rotas, prazos de tempo de trânsito de carga e valor do frete de boa parte do país. Em seguida aparecem os nodais secundários polifuncionais, aqueles em que os circuitos espaciais de produção industrial são o suporte das atividades geradoras de carga, e monofuncionais, relacionados à especialização produtiva, situação geográfica e logística do comércio atacadista e distribuidor. O quarto nível agrega o conjunto dos nodais terciários, centros responsáveis pela distribuição de rotas microrregionais e intraurbanas em cidades intermediárias. Procuramos comprovar, ainda, que a modernização conservadora e as históricas e crônicas desigualdades regionais não podem ser explicadas alheias ao vertiginoso crescimento do transporte rodoviário de carga, em toda a complexidade que a temática implica. Em outras palavras, acreditamos que para compreender as contradições do Brasil no período atual é necessário um entendimento geográfico mais completo do enraizamento e capilaridade do modal rodoviário em apenas cinco décadas. / The road freight transport is the object of study of this thesis, which assumes that its structure and organization in the Brazilian territory were followed by a selective spatial process that privileged certain points and areas in detriment of others, highlighting a geographic network which reveals the land use. The hypothesis also takes into account the fact that the road freight transport, from the mid-1990s, entered into a time of structural changes and conjunctures consistent with the variables of the current historical period, consequence of the perverse globalization that overwhelms the world with hegemonic events that serve the designs of capital. We intend to demonstrate that the road cargo freight creates a proper topology, whose territorial configuration consists of nodals and lines which together creates a geographic network model capable of expressing the interactions and geographic dissociation of places, intrinsic to the Brazilian social and spatial formation. We believe that this way, methodologically based on the labor territorial division, in the circuits of the urban economy and in productive space circuits, provides a very interesting reading in regards to the different uses of the territory, strongly highlighting the hierarchy of places and the correlation forces between the agents operating the road cargo freight. To confirm this idea, we identify the nodals regarded as the ultimate expression of the road freight spatial selectivity and divided into four levels that, to concentrate a number of geographic attributes which produces functionalities, hierarchies and polarities, help explain the geographic network in question. The starting point is what we propose to call \"paulista polygon\", a primary nodal with unique polarizing force, responsible for determining the routes, cargo transit deadlines and freight value of much of the country. Next there are the secondary polyfunctional nodals, those in which the spatial circuits of industrial production are the support of the charge-generating activities, and monofunctional, related to production specialization, geographic situation or logistic trade of the wholesaler and distributor. The fourth level adds the set of tertiary nodals, centers responsible for the microregional route distribution and within the urban areas in intermediate cities. We also seek to prove that the conservative modernization and historical and chronicle regional differences cannot be explained apart from the vertiginous growth of road freight transport in all its complexity. In other words, we believe that to understand the contradictions of Brazil in the current period, requires a more complete geographical understanding of the rooting and capillarity of the road modals in just five decades.
20

Avaliação de desempenho do transporte rodoviário de cargas pelo método de análise envoltória de dados - DEA / Performance evaluation of the freight road transport using the data envelopment analysis method - DEA

Athayde, Andrea Hora 14 March 2003 (has links)
O transporte rodoviário de cargas no Brasil apresenta um número reduzido de estudos principalmente no que se refere às informações sobre seu desempenho. A avaliação de desempenho sempre foi um tema de grande importância para o planejamento de transportes. Atualmente, com o acirramento da competição, seu conhecimento torna-se indispensável para a sobrevivência das empresas, que devem mudar suas gestões de uma visão puramente operacional para uma visão de negócios. O objetivo do trabalho de pesquisa é explorar o potencial da aplicação do método de análise envoltória de dados (Data Envelopment Analysis - DEA) para a avaliação de desempenho de empresas prestadoras de serviços de transporte rodoviário de cargas. Esta ferramenta determina a eficiência relativa de cada unidade em análise (DMU), comparando-a com as demais e considerando a relação entre seus insumos (inputs) e produtos (outputs). No trabalho, é descrito o método acompanhado por uma aplicação prática que determina a eficiência de empresas do setor. A partir daí, foram construídas as tabelas de classificação de desempenho (rankings) destas empresas que serviram para estudos comparativos com outras tabelas divulgadas anualmente numa revista brasileira da área. / The freight road transport in Brazil presents a reduced number of studies mainly in what it refers to performance information. The performance evaluation was always a theme of great importance in transport planning. Nowadays, because of the raise in competition, your knowledge becomes indispensable for the companie\'s survival, which should change your vision of management from purely operational to business. The objective of this work is to explore the application potential of the Data Envelopment Analysis (DEA) method for the performance evaluation of companies which transport loads. The DEA method determines the relative efficiency of each unit in analysis (DMU) comparing it to the others units, and considering the relationship among inputs and outputs. In this work, the method is described followed by a practical example that determines the efficiency of the companies. Since then, rankings of performance of these companies were built for comparative studies with other ranking published annually in a specialized Brazilian magazine.

Page generated in 0.0633 seconds