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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.
161

Characteristics and contributory causes related to large truck crashes (phase-II) - all crashes

Kotikalapudi, Siddhartha January 1900 (has links)
Master of Science / Department of Civil Engineering / Sunanda Dissanayake / In order to improve safety of the overall surface transportation system, each of the critical areas needs to be addressed separately with more focused attention. Statistics clearly show that large-truck crashes contribute significantly to an increased percentage of high-severity crashes. It is therefore important for the highway safety community to identify characteristics and contributory causes related to large-truck crashes. During the first phase of this study, fatal crash data from the Fatality Analysis Reporting System (FARS) database were studied to achieve that objective. In this second phase, truck-crashes of all severity levels were analyzed with the intention of understanding characteristics and contributory causes, and identifying factors contributing to increased severity of truck-crashes, which could not be achieved by analyzing fatal crashes alone. Various statistical methodologies such as cross-classification analysis and severity models were developed using Kansas crash data. Various driver-, road-, environment- and vehicle- related characteristics were identified and contributory causes were analyzed. From the cross-classification analysis, severity of truck-crashes was found to be related with variables such as road surface (type, character and condition), accident class, collision type, driver- and environment-related contributory causes, traffic-control type, truck-maneuver, crash location, speed limit, light and weather conditions, time of day, functional class, lane class, and Average Annual Daily Traffic (AADT). Other variables such as age of truck driver, day of the week, gender of truck-driver, pedestrian- and truck-related contributory causes were found to have no relationship with crash severity of large trucks. Furthermore, driver-related contributory causes were found to be more common than any other type of contributory cause for the occurrence of truck-crashes. Failing to give time and attention, being too fast for existing conditions, and failing to yield right of way were the most dominant truck-driver-related contributory causes, among many others. Through the severity modeling, factors such as truck-driver-related contributory cause, accident class, manner of collision, truck-driver under the influence of alcohol, truck maneuver, traffic control device, surface condition, truck-driver being too fast for existing conditions, truck-driver being trapped, damage to the truck, light conditions, etc. were found to be significantly related with increased severity of truck-crashes. Truck-driver being trapped had the highest odds of contributing to a more severe crash with a value of 82.81 followed by the collision resulting in damage to the truck, which had 3.05 times higher odds of increasing the severity of truck-crashes. Truck-driver under the influence of alcohol had 2.66 times higher odds of contributing to a more severe crash. Besides traditional practices like providing adequate traffic signs, ensuring proper lane markings, provision of rumble strips and elevated medians, use of technology to develop and implement intelligent countermeasures were recommended. These include Automated Truck Rollover Warning System to mitigate truck-crashes involving rollovers, Lane Drift Warning Systems (LDWS) to prevent run-off-road collisions, Speed Limiters (SLs) to control the speed of the truck, connecting vehicle technologies like Vehicle-to-Vehicle (V2V) integration system to prevent head-on collisions etc., among many others. Proper development and implementation of these countermeasures in a cost effective manner will help mitigate the number and severity of truck-crashes, thereby improving the overall safety of the transportation system.
162

Using Mixed Methodology to Assess High Risk Sexual Behavior and Adult Stage among Bolivian Truck Drivers

Sorensen, William 19 December 2003 (has links)
Bolivia has a high STI rate and an accelerating HIV/AIDS rate. The majority of the country's newly diagnosed HIV/AIDS cases come from the province of Santa Cruz in eastern Bolivia, where this study took place. In this study, the investigator assessed the notion that Bolivian truck drivers are a bridge population of HIV transmission within heterosexual networks. This investigation determined risks of HIV/STI transmission through interviews, surveys, and workshops given to the truck drivers. Special attention was given to self reports of sexual behavior, cognitions and ego maturation stages, in order to assess risk. Mixed methodology was the research paradigm of choice, utilizing qualitative and quantitative phases. Workshops were designed, implemented, and evaluated. Analysis was completed on survey results from 246 male truckers (aged 18 to 67). More than half (56%) of these truckers admitted to having sex with casual partners. In addition, from 30% (quantitative inquiry) to 52% (qualitative inquiry) of these truck drivers have had sexually transmitted infections. Three factors predicted condom use: Age, Outcome expectancies, and Perceived social norms. Only one factor predicted STI history: Number of sex partners. Adult stage theory did not directly impact sexual behavior. A high risk of HIV/STI transmission has been detected in Bolivian truck drivers. This notion supports other studies involving truck drivers, and calls attention to the need for tailored health education programs for this population. Furthermore, younger truck drivers are at greater risk of HIV transmission than older truck drivers, in spite of their increased condom use. Sexual health workshops for Bolivian truck drivers are worthwhile and can be most effective when co-managed with truck companies or unions. Counseling, testing, and follow up research programs can best be implemented through these already-existing management structures. Future programs need to emphasize other behaviors besides condom use. Workshops should also include truckers' spouses as participants. Lastly, since casual sex partners of truck drivers rarely fit the mold of a commercial sex worker, effort should be made to describe these casual partners and design subsequent workshops for them.
163

Regulace kaminonové dopravy - hours of service / Regulation of truck transport - hours of service

Kameník, Josef January 2010 (has links)
Thesis is concerned with one of many regulations which affects cargo truck transport, so-called hours of service. It is restriction related to time of drivers' service. Truck transport means important part of economy as connection between companies or between company and final consumers. Aim of the work is compare regulations in European Union, Canada and USA together with their historical evolution. Differences in regulation are then explained in model transport relations. There are also analyzed individual interested groups which are influenced by these regulations. In final part of the work is looked about pro and con of existing restriction and what are the consequences of observance of the rules or even tightening up the rules.
164

[en] PLANNING OF TRUCK SEQUENCING IN ASSEMBLY-TO-ORDER PRODUCTION ENVIRONMENT / [pt] PLANEJAMENTO DO SEQUENCIAMENTO DE CAMINHÕES EM UM AMBIENTE DE PRODUÇÃO SOB ENCOMENDA

SARA SOLANGE PARGA CARNEIRO 06 November 2013 (has links)
[pt] A maioria das pesquisas científicas publicadas sobre sequenciamento da produção na indústria automobilística consideram os pedidos já alocados em um dia ou turno de trabalho, desconsiderando especificidades do planejamento da cadeia de suprimentos. Esta dissertação procura contribuir no campo do planejamento da produção, propondo um modelo matemático de programação inteira mista que aborda de maneira integrada dois problemas de otimização fundamentais da cadeia: o problema de seleção de pedidos e o problema de sequenciamento de carros em uma única linha de montagem. A fim de abordar questões bem próximas a realidade, incluindo apresentação de experimentos numéricos com o modelo proposto, utilizou-se como cenário o segmento de caminhões, dentro da indústria automotiva. Considerou-se, como objetivo no modelo, além das abordagens tradicionais (minimizar sobrecarga de trabalho, troca de cores e violação de restrições), a demanda dos clientes com relação a prazos de entrega do pedido – principal reforço para uma indústria que pretende cada vez mais migrar para um ambiente de produção orientado pela demanda. / [en] Most published scientific research on production sequencing in the automotive industry consider orders already allocated in a day or shift, disregarding specificities of supply chain planning. This paper aims to contribute in production planning field, proposing a mathematical model of mixed-integer programming that addresses in a integrated way two fundamental problems from chain: the problem of order selection and car sequencing problem on a single assembly line. In order to approach practical issues, including presentation of numerical experiments from proposed model, the truck segment within the automotive industry was used as scenario. It was considered as objective in the model, beyond traditional approaches (minimize work overload, color changing and violation of restrictions), customer demand with respect promised due dates, the main reinforcement for an industry that increasingly want migrate to a production environment driven by demand.
165

Inventory policy planning for spare parts and its application in the heavy-duty truck and bus industry

Azran, Simon January 1994 (has links)
A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science in Engineering. Johannesburg, November 1994. / Inventories are produced, used (e.g. for raw materials, supplies, spare parts, and So forth) or distributed by every organisation. Moreover, inventories represent a major investment from the perspectives of both individual firms and entire national economies. In addition, enormous costs are incurred in the planning, scheduling, control and actual carrying out of replenlshment-Iprocuretnentl related activities. Interest in the subject of inventory management is constantly increasing, yet Silver and Petarsonlll (P(eface) found that "although invi ,~ory management ha.l been studied in considerable depth from a theoretical perspective, yet, those of us who, throuah consulting work, come into. clos>!)contact with mananerlal decision procedures in this arer are repeatedly surprised to find how limited, and ad hoc, many of the existing decision systems actually are. The rate at which theory has been developed has far outstripped the rate at which decision practices of firms have been successft,Jlly upgraded. A major g~o has existed between the theoretical solutions, on the one hand, and the real world problems, on the other". Inventory control is the science-based art of ensuring that lust enough inventory (or stockl is held by an organisation to meet both its internal and external demand commitments economically. There can be disadvantages in holding either too much 01 too little inventory. Therefore, inventory control is primarily concerned with obtaining the correct inventory with compromise between these two extremes. The control and maintenance of inventories is a problem common to all enterprises in any sector of a given economy. The primary aim of this study is to identify What the inventory policy of a company shoull;I be to Secure a reduction in inventory-related costs while maintaining a high level of customer service. Lewis(2) defines two bMlt:~ tvpes of inventory policy. Those in which decisions concerning replenishment are based on the lellel of inventory held, are known as "fixed-order quantity models" or "re-order level policies" and those in which such declslons arc made on a time basis are known as "fixed-time period models" or "re-order cycle policies". According to Nadder(3) (7I 11) the basic distinction between fixed-order quantity models and fixed-tlme period models is that the former are "event-triggered" while the latter are "time-triggered". That is, a fixed-order quantity model initiates an order when the "event" of reaching a specified re-order level occurs. This event may take place at any time, depending on the demand for the items considered. In contrast, the fixed-time period model is limited to placing orders at the end of a predetermined time period; hence, the passage of time alone "triggers" the model. In this thesis, we shall discuss both classical inventory models and heuristic models. We shall also conduct an investigation into the factors affecting high levels of inventory ~ mainly lead times (supplier and internal lea' times) in relation to spare 9arts in the heavv-dutv truck and bus industry. The thesis also suggests guidelines for controlling stock or these types of commodities in a practical environment. This will be done by either researching the existing inventory models or developing new inventory models or a combination of both, the intention being not to look for absolute optimisation, but rather to achieve significant improvements over current operations. / GR 2016
166

Analysis of Customisation in a Modular System : Development of a New Seat Solution

Pettersson, Josefine, Colling, Johanna January 2019 (has links)
Today there is a shift from mass production to mass customisation due to changing customer needs in the global market. This thesis report analyses customisation in a modular system through a case study in the truck industry with focus on development of a new seat solution. The customer requests showed a demand for one to two additional seats in the cab. In order to answer to various customer needs, companies implement modular product development principals which enables them to produce in a rapid speed, minimize costs, increase performance and produce a high mix of products. The established RQ:s were: RQ1: How do companies improve competitiveness by translating customer needs into technical requirements? RQ2: What are the challenges and possibilities when making changes in a modular system? The thesis followed the first steps in the product development process due to delimitations in time, scope, and research quality. The data was collected through a literature study, interviews with customers and archival records and documentations at the case company. The study resulted in two final concepts, namely a seat solution and a bench solution which answered to the customer need of one to two additional seats in the cab. A conclusion was that it is crucial for companies to understand the in-depth customer needs to provide higher customer value, which in turn can contribute to strengthen the companies’ competitiveness. The correct translation of customer needs to technical requirements is essential for the development of a modular system. Challenges and possibilities when making changes in a modular system was found to be design complexity along with opportunity to reuse existing components. Both the translation of customer needs and design decisions regarding a modular system is achieved in the earlier stages of the product development process. It is thus of high importance to translate the customer needs correctly and make thoughtful decisions of the modules in the modular system to ensure company competitiveness.
167

Wireless weight display

Eriksson, Joar, Oresten, Filip January 2019 (has links)
No description available.
168

"Desenvolvimento de pesquisa-ação com caminhoneiros de estrada: trabalhando na problematização as questões voltadas à sexualidade, DST/AIDS e drogas" / Development of Research-Action with truck drivers: working about the problematization and the questions related to the sexuality, STD/AIDS and drugs. 2003.

Nascimento, Evania 19 December 2003 (has links)
Os caminhoneiros de estrada constituem um grupo de grande mobilidade geográfica em função do trabalho – o transporte de cargas, que exige vários dias até meses fora de suas casas e longe da família. A solidão a que se vêem condicionados torna alguns destes profissionais vulneráveis a manterem relacionamentos sexuais no transcurso das viagens. Assim, este estudo tem por objetivo investigar os fatores de vulnerabilidade entre os caminhoneiros de estrada para o risco de contaminação com o HIV/aids. A metodologia utilizada foi o método quali-quantitativo que teve como eixo norteador a pesquisa – ação e o método da problematização de Paulo Freire. A coleta de dados foi realizada no período de janeiro a fevereiro de 2003, através de uma entrevista semi-estruturada. Foram entrevistados neste período 50 caminhoneiros de estrada presentes nas cooperativas que serviram de campo para este estudo. A análise dos dados quantitativos foi feita com base na estatística descritiva e os dados qualitativos através do método de Bardin (1979). Os resultados encontrados apontam que os caminhoneiros têm conhecimentos sobre vários aspectos da transmissão da aids, mas muitos se envolvem em relacionamentos sexuais na estrada sem o uso do preservativo. Por outro lado, o uso de álcool e anfetaminas (para reduzir o sono) faz parte do cotidiano de alguns destes profissionais, constituindo fatores de vulnerabilidade, uma vez que sob o efeito da bebida nos pontos de paradas para descanso alguns se envolvem com prostitutas. Finalmente, concluímos que os comportamentos observados entre os caminhoneiros estão fundamentados em princípios socialmente construídos com base na cultura machista, levando muitos a se envolverem no sexo sem proteção ou a aventuras como forma de mostrar sua virilidade a qualquer custo, tornando-os, deste modo, vulneráveis a DST/aids. / The truck drivers constitute a group of great geographical mobility through the cargo transport that requires many days and until months far from their family and home too. The loneliness that they are conditioned, lead some these professionals to vulnerability and to keep sexual relations during their journeys through the highway. Thus, this study aims to investigate the vulnerability factors among truck drivers to the risk of HIV/AIDS’ contamination. The methodology utilized in this study was the quanti-qualitative method that had as the reference the research-action and the Paulo Freire’s problematization method. The data were collected in the months of January to February 2003 through the semi-structured interview. Fifty truck drivers were interviewed in the cooperatives that served as place to this study. The analysis of the quantitative data was based on descriptive statistic and the qualitative data through the Bardin’s method (1979). The results indicate that the truck drivers have knowledge about the several aspects of AIDS’ transmission, but many of them involve to sexual relations in the highway without use of condom. On the other hand, the use of alcohol and amphetamine (to reduce the sleep) is present in the daily life of some them and constitute vulnerability factors in the stop points to rest where the use of alcoholic beverages facilitates the sexual relations together whores. At last, we can conclude that the watched behaviors among the truck drivers are founded in socially built principles based on the culture of masculinity leading many of them to involve in sexual relations or just adventure without use of condom to show their virility all time, becoming them so vulnerable to STD/AIDS.
169

Designação de rotas para frota dedicada em uma rede de distribuição de linha branca. / Assigning lanes to dedicated fleet in a white goods distribution network.

Stringher, Fabiano Gadini 31 May 2004 (has links)
Esta dissertação apresenta um problema de otimização relacionado com a designação de rotas de carga completa para frota própria ou dedicada, visando a minimização dos custos de transporte numa rede de distribuição formada por fábricas uni-produto, centros de distribuição (consolidação) e clientes. Essas rotas são conjugadas formando ciclos fechados (viagens) para garantir a otimização do tempo através do movimento contínuo desta frota dedicada. A metodologia é aplicada em uma rede de distribuição de um fabricante de linha branca no Brasil. Além dos resultados econômicos favoráveis, outras contribuições para o tema de conjugação de rotas foram encontradas nesta dissertação, tais como, a regra de formação de caminhos, o limite para conjugação de rotas numa rede de distribuição e o desenvolvimento de uma estrutura para custear esses caminhos conjugados. O modelo de programação linear inteira desenvolvido mostrou-se apto a resolver problemas de tamanho real em tempo factível, mesmo com recursos computacionais comuns. / This thesis presents an optimization problem regarding the assignment of truckload lanes to a private or dedicated fleet to minimize transportation costs in a distribution network formed by single-product plants, distribution (consolidation) centers and clients. These lanes are conjugated in order to form closed cycles (trips) to guarantee time optimization through continuous movement of this dedicated fleet. This methodology is applied to a distribution network of a white goods manufacturer in Brazil. More than good economic results, there are others contributions for the theme of conjugated lanes in this thesis, such as, the rule of formation trips, the limit to conjugated lanes to a distribution network and the development of a structure to get the conjugated lanes\' costs. The model of integer linear program that was development is capable to solve the real problems in a reasonable time, even if with regular.
170

Faixas adicionais para aclives de rodovias brasileiras / Climbing lanes on upgrades of Brazilian highways

Melo, Ricardo Almeida de 10 June 2002 (has links)
O objetivo da tese foi adaptar, para as condições das rodovias brasileiras, as diretrizes da AASHTO para projetos de faixas adicionais de subida. Esta adaptação foi feita através de três aspectos: (i) geração de curvas de desempenho para caminhões típicos brasileiros; (ii) determinação da redução admissível de velocidade para caminhões; e (iii) estimativa do fluxo e da porcentagem de caminhões no tráfego que justifiquem economicamente a construção da faixa adicional. Quanto ao primeiro aspecto, constatou-se que as relações massa/potência encontradas para caminhões brasileiros (variam de 100 a 380 kg/kW) são significativamente maiores que a dos caminhões norte-americanos (120 kg/kW), o que inviabiliza o uso das curvas de desempenho que constam do livro verde da AASHTO. Nesta pesquisa, um modelo de locomoção de veículos foi calibrado e validado, logo após foram geradas curvas de desempenho para sete categorias de caminhões brasileiros. No segundo aspecto, as relações entre as diferenças de velocidade entre automóveis e caminhões, e índices de envolvimento de caminhões em acidentes foram obtidas. Para atingir esse objetivo, foram coletados dados sobre acidentes envolvendo caminhões, velocidade de veículos em aclives e volume diário médio. As relações foram comparadas com a utilizada nas diretrizes da AASHTO e as diferenças encontradas sugerem que a redução admissível na velocidade dos caminhões brasileiros deve ser de 20 km/h, em rodovias de pista simples, e de 35 km/h, em rodovias de pista dupla, se o índice de envolvimento de caminhões em acidentes for o que corresponde à redução máxima de velocidade admitida pela AASHTO (15 km/h). Em relação ao terceiro aspecto, foram analisadas relações benefício/custo para diversos cenários, visando estimar os fluxos de tráfego para os quais os custos fossem iguais aos benefícios. Os custos foram estimados a partir do investimento de capital necessário para a construção da ) faixa adicional, com base em projetos típicos do estado de São Paulo. Os benefícios estimados foram a redução do tempo de viagem e dos custos operacionais dos carros, ônibus e caminhões descarregados. Para a estimativa dos tempos de viagem, porcentagem do tempo trafegando em pelotões e porcentagem média de veículos em pelotões, foram feitas simulações, com e sem a faixa adicional, usando-se o modelo TRARR. Nessas simulações, os fluxos variaram entre 50 a 700 veíc/h e as porcentagens de caminhões de 10% a 40%. Os resultados indicam que os fluxos mínimos no aclive, que justifiquem economicamente a construção da faixa adicional, dependem da porcentagem de caminhões e da magnitude do aclive, variando de 340 veíc/h (10% de caminhões; aclives de até 3%) a 185 veíc/h (30% de caminhões; aclives de mais de 3%). / The objective of the research reported in this PhD dissertation was to adapt the AASHTO guidelines for design of climbing lanes to the Brazilian highways characteristics. This adaptation was carried out with regard to three aspects: (i) development of performance curves for typical Brazilian trucks; (ii) determination of the maximum speed reduction of slow trucks on upgrades; and (iii) estimation of minimum upgrade traffic flow rates and truck percents that would warrant the construction of climbing lanes on two-lane highways, from cost-effectiveness approach. Regarding the first aspect, it was verified that mass/power ratios for Brazilian trucks vary between 100 and 380 kg/kW and significantly differ from the ratio taken by AASHTO as representative of the average North-American truck (120 kg/kW); therefore, the truck performance curves from the AASHTO green book should not be used to design climbing lanes in Brazil. The green book\'s performance curves can be replaced by a family of performance curves for Brazilian trucks generated by a truck locomotion model, which was calibrated and validated in this research. With regard to the second aspect analyzed, the relationship between speed difference and truck accident involvement rates was studied. Data about truck accidents, speeds and annual average daily traffic were collected. These functions were compared to the one presented in the green book and the differences found suggest that, for the same truck accident involvement rate used to establish the maximum truck speed reduction adopted in the AASHTO policy (15 km/h), the admissible truck speed reduction on Brazilian roads would be 20 km/h on two-lane highways and 35 km/h on divided highways. With regard to the third aspect, benefit/cost ratios for several scenarios were analyzed in order to estimate upgrade traffic flow rates that would warrant the provision of climbing lanes. (continue) (continuation) The costs were estimated on the basis of the capital costs for the construction of the climbing lane, based on costs of climbing lanes built in the state of São Paulo. The benefits were estimated from the reduction of travel time and vehicle operating costs provided by the construction of a climbing lane. Travel times, percent time spent following, and average fraction of vehicles travelling in platoons with and without the climbing lane were estimated by means of traffic flow simulations carried out with TRARR. The simulations were run using traffic flows ranging from 50 to 700 veh/h, with truck percents varying from 10% to 40%. The results indicated upgrade traffic flow rates that warrants climbing lanes varying with truck percents and grades magnitude and range from 340 veh/h (grades of up to 3%, 10% trucks in flow) to 185 veh/h (grades of more than 3%, with 30% trucks).

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