• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 130
  • 15
  • 12
  • 8
  • 5
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 211
  • 211
  • 50
  • 33
  • 32
  • 30
  • 29
  • 28
  • 27
  • 25
  • 25
  • 23
  • 23
  • 21
  • 18
  • 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.
171

Concepção de veículo motorizado elétrico modular de acoplamento universal em cadeira de rodas / Conception of modular electric motor vehicle of universal attachment in standard wheelchair

Alves, Júlio Oliveto [UNESP] 08 August 2017 (has links)
Submitted by JÚLIO OLIVETO ALVES null (julio.oliveto@gmail.com) on 2017-08-29T12:48:26Z No. of bitstreams: 1 versão digital - VEÍCULO MOTORIZADO ELÉTRICO MODULAR DE ACOPLAMENTO UNIVERSAL EM CADEIRAS DE RODAS MECANOMANUAL.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-29T13:09:02Z (GMT) No. of bitstreams: 1 alves_jo_dr_guara.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) / Made available in DSpace on 2017-08-29T13:09:03Z (GMT). No. of bitstreams: 1 alves_jo_dr_guara.pdf: 6431267 bytes, checksum: 267c216f343be2e22e3e8daad61fe7a8 (MD5) Previous issue date: 2017-08-08 / O presente trabalho de pesquisa consiste na concepção de um veículo motorizado elétrico modular de acoplamento universal em qualquer modelo de cadeira de rodas mecanomanual. Trata-se de um equipamento eletro-mecânico, disponibilizado em forma de acessório, com estrutura física simplificada e alta tecnologia eletrônica aplicada capaz de proporcionar ao cadeirante maior liberdade de movimentação sem desgastes físicos. A aliança entre o design inclusivo e a área médica pode se relevar um passo importante na obtenção de produtos direcionados para as necessidades reais de pessoas com condições físicas e psíquicas particulares, melhorando o seu bem-estar e capacidade de execução de atividades no dia a dia. Desta forma, o presente trabalho é direcionado pelos fundamentos do design inclusivo com o principal ponto focal no usuário, mas que apresenta outros dois importantes pilares adotados em sua metodologia de desenvolvimento, sendo eles, o benchmarkig e o estudo de Normas Técnicas aplicadas no desenvolvimento de equipamentos assistivos. São apresentadas as etapas de desenvolvimento, ensaios com base em Normas Técnicas e teste de usabilidade. Busca-se evidenciar todo o processo de design de equipamento, assim como o estudo teórico de estabilidade e montagem do protótipo funcional. Os ensaios baseados na Norma Técnica ABNT NBR ISO 7176 permitem o entendimento do comportamento dinâmico e funcional do protótipo em termos de estabilidade estática, eficácia dos freios, consumo de energia, velocidade máxima, aceleração, desaceleração e capacidade de transposição de obstáculos. Por fim, discute-se a análise de resultados dos ensaios junto aos resultados teóricos calculados e pré-requisitos estabelecidos. / The thesis consists in the conception of a modular electric motor vehicle that can be attached in any model of standard wheelchair. It is an electro-mechanical equipment, available as an accessory, with a simplified physical structure and high applied electronic technology capable of giving the wheelchair greater freedom of movement without physical wear and tear. The union between inclusive design and the medical field can be an important step in obtaining products aimed at the real needs of people with particular physical and psychological conditions, improving their well-being and ability to do their daily activities. In this way, the thesis is guided by the fundamentals of inclusive design with the main focal point in the user, by the way presents two other important pillars adopted in its development methodology, being the benchmarkig and the study of Technical Standards applied in the development of Assistive devices. The stages of development are presented, tests based on Technical Standards and usability testing. The aim of this work is to demonstrate the whole process of equipment design, as well as the theoretical study of stability and assembly of the functional prototype. The tests based on the Technical Standard ABNT NBR ISO 7176 allow the understanding of the dynamic and functional behavior of the prototype in terms of static stability, brake efficiency, power consumption, maximum speed, acceleration, deceleration and obstacle transposition capacity. Finally, we discuss the analysis of the results of the tests together with the calculated theoretical results and established prerequisites.
172

Estratégia para detecção e rastreamento de faixas rodoviárias utilizando uma câmera monocular / Road lane detection and tracking strategy using a monocular camera

Andrade, David Carvalho 24 April 2017 (has links)
No setor automotivo, os sistemas de auxílio ao condutor são desenvolvidos para reduzir os efeitos colaterais do nível de mobilidade atingido atualmente, como os acidentes de trânsito e os congestionamentos. Em uma perspectiva futura, pretende-se atingir o nível de direção autônoma e cooperativa baseada em redes de sensores. A estratégia de detecção e rastreamento de faixas rodoviárias proposta neste trabalho se enquadra nos requisitos funcionais de alguns desses sistemas, como o Lane Departure Warning (Aviso de Saída de Faixa) e o Lane Keep Assist (Assistência de Manutenção de Faixa). O desenvolvimento do algoritmo foi organizado em três níveis de processamento; baixo, médio e alto. Na etapa de processamento de baixo nível realizam-se as operações de preparação e melhoramento da imagem de entrada, na etapa de nível médio realiza-se a extração das características de interesse e a etapa de alto nível consiste da técnica de rastreamento da posição das faixas. Avaliou-se a resposta do algoritmo, para as amostras escolhidas, por meio de métricas baseadas no distanciamento das faixas rastreadas em relação à posição original das mesmas. Constatou-se que a estratégia apresenta boa precisão nos cenários considerados ideias, inclusive com a presença de sombras, curvas, aclive e declive na estrada. Contudo, essa precisão é comprometida quando a faixa é segmentada, mal sinalizada e quando o reflexo na pista ou o ofuscamento afeta a captura da imagem pela câmera. / In the automotive field, driver assistance systems are developed to reduce the collateral effects of the actual level of mobility, such as traffic jams and accidents. In a future perspective, it is intended to achieve the level of autonomous and cooperative driving based on sensor networks. The proposed strategy for road lanes detection and tracking fits as a functional requirement for some of these systems, as the Lane Departure Warning and Lane Keep Assist. The algorithm development was structured based in three processing levels: low, mid and high levels. The low-level processing enhances the input image, the mid-level processing is an interest feature extractor, and the high-level is the lane position tracking strategy. The algorithm's response evaluation, for the chosen samples, was realized with metrics based on the deviation between the tracked and the original lane. The strategy shows good accuracy levels at the ideal scenario, including shadows, curves, and road slope. However, the accuracy is impaired if the lane is dashed, badly signalized and if road reflection or dazzle harm the image capture by the camera.
173

Estratégia para detecção e rastreamento de faixas rodoviárias utilizando uma câmera monocular / Road lane detection and tracking strategy using a monocular camera

Andrade, David Carvalho 24 April 2017 (has links)
No setor automotivo, os sistemas de auxílio ao condutor são desenvolvidos para reduzir os efeitos colaterais do nível de mobilidade atingido atualmente, como os acidentes de trânsito e os congestionamentos. Em uma perspectiva futura, pretende-se atingir o nível de direção autônoma e cooperativa baseada em redes de sensores. A estratégia de detecção e rastreamento de faixas rodoviárias proposta neste trabalho se enquadra nos requisitos funcionais de alguns desses sistemas, como o Lane Departure Warning (Aviso de Saída de Faixa) e o Lane Keep Assist (Assistência de Manutenção de Faixa). O desenvolvimento do algoritmo foi organizado em três níveis de processamento; baixo, médio e alto. Na etapa de processamento de baixo nível realizam-se as operações de preparação e melhoramento da imagem de entrada, na etapa de nível médio realiza-se a extração das características de interesse e a etapa de alto nível consiste da técnica de rastreamento da posição das faixas. Avaliou-se a resposta do algoritmo, para as amostras escolhidas, por meio de métricas baseadas no distanciamento das faixas rastreadas em relação à posição original das mesmas. Constatou-se que a estratégia apresenta boa precisão nos cenários considerados ideias, inclusive com a presença de sombras, curvas, aclive e declive na estrada. Contudo, essa precisão é comprometida quando a faixa é segmentada, mal sinalizada e quando o reflexo na pista ou o ofuscamento afeta a captura da imagem pela câmera. / In the automotive field, driver assistance systems are developed to reduce the collateral effects of the actual level of mobility, such as traffic jams and accidents. In a future perspective, it is intended to achieve the level of autonomous and cooperative driving based on sensor networks. The proposed strategy for road lanes detection and tracking fits as a functional requirement for some of these systems, as the Lane Departure Warning and Lane Keep Assist. The algorithm development was structured based in three processing levels: low, mid and high levels. The low-level processing enhances the input image, the mid-level processing is an interest feature extractor, and the high-level is the lane position tracking strategy. The algorithm's response evaluation, for the chosen samples, was realized with metrics based on the deviation between the tracked and the original lane. The strategy shows good accuracy levels at the ideal scenario, including shadows, curves, and road slope. However, the accuracy is impaired if the lane is dashed, badly signalized and if road reflection or dazzle harm the image capture by the camera.
174

Analýza bezpečnosti silničního provozu v systému "člověk - technika - prostředí". / Analysis of the Safeness of Traffic Operation in the System "Man - Technics - Environs".

MATOUŠEK, Lukáš January 2007 (has links)
This dissertation is based on the analysis of causes of traffic accidents in traffic operations and on portion of driver, self-propelled motor vehicle and terrestrial communications on it. On the basis of these analyses there are finished general conclusions for decreasing of traffic accident frequencies.
175

Design And Development Of An Improved Anti-Lock Braking System For Two-Wheelers

Mohan, S 08 1900 (has links) (PDF)
In today’s fast moving world, automobiles are facing challenges in terms of having to survive road accidents, increasing traffic, bad road-conditions and high/express ways. Brake systems play a vital role in controlling the vehicle speed while avoiding road accidents. The conventional brake systems consist of basically an actuator, transmission and frictional parts. This system is difficult for manipulated control by the driver during emergency and panic braking situations. In particular road and environmental conditions, it requires certain skill to have safe and effective brake control, which is always not possible from all drivers. Wheel locking is a predominant phenomenon during panic braking and this will cause vehicle skidding resulting in injuries and road accidents. In the case of a two-wheeler, being a single-track vehicle, skidding is one of the major causes for fatal road accidents due to loss in lateral balance. As the road safety regulations are becoming more stringent, the anti-lock brake systems (ABS) will replace the conventional brake systems in all road vehicles to avoid accidents and to improve vehicle safety. Early ABS systems, developed in the last 100-years, use intermittent and cyclic brake pressure control by sensing the wheel speed or wheel-slip as one of the major control inputs. Regulating the brake pressure with a preset threshold value is another method. These ABS systems have used electronics, or hydraulics or pure mechanical control. However, such ABS are not widely used in two-wheelers and other low cost vehicles till now, because of several limitations identified as follows: High cost, power supply needed for its operation in the case of intermittent and cyclic brake control, susceptibility to failure in the electronics system, interference from RF signals (from cell-phones for example), uneasiness to drivers from pedal pulsations with pedal noise, heavier weight, increased vehicle vibrations and failure modes of wheels due to torsional vibrations. The present research work is carried out to develop a new mechanical ABS concept, which will address most of the above problems. During braking, the change in rider-input force will change wheel reactions. This change is made proportional to the change in rider input force only upto wheel locking. Such a principle is used to develop the new mechanical ABS. The new concept regulates the output force from the ABS, by sensing the dynamic wheel reactions with increase in rider-response. The ABS output force is regulated by one of the following ways: (a) Slipping-down the lever-ratio or (b) preventing the excessive brake input force. Based on the parameters like less number of parts, least weight, simplicity, reliability, efficiency, durability, time-response, etc., the second method (of preventing the excessive brake input force) has been chosen. Further a new concept of ABS interconnecting system is proposed for usage between the front and rear wheels of the vehicle. This interconnecting system will ensure that the two mechanical ABS systems function at any kind of braking-balance between the front and rear applications. An analytical vehicle model has been developed with several input parameters like mass, geometry, inertia, aerodynamic properties, frictions of road and bearing-supports, road gradients, etc. From this analytical model, the dynamic wheel reactions and limiting adhesion of each tyre for various braking conditions are determined and the results are used to design the mechanical ABS. The same analytical model is used to predict the brake performance like stopping distance, vehicle deceleration and the vehicle speed variation for ideal braking conditions. The new ABS is modelled in Pro-E using the inputs from the analytical model. To evaluate the concept, a functional proto-type is built and fitted on a motorcycle. The ABS is evaluated for its functionality and performance at different road (level surface, up-gradients and down gradients) and environmental conditions (dry and wet road conditions). Using the VBOX II, proximate sensors and load-cells fitted on the vehicle, the vehicle stopping distance, wheel slip and pedal force are measured. The results show that wheel locking does not occur under panic driving conditions, which is the primary objective. In addition, the results show a good agreement with the predicted stopping distance and vehicle deceleration from the analytical model. As there is good scope for this new mechanical ABS for use in two-wheelers and other low cost vehicles, further research is needed to make this system work in curvilinear motion & banked surfaces.
176

An assessment of application of intelligence-driven investigation in the combating of organised vehicle theft in Thohoyandou Cluster

Bila, Hlengani Phanuel January 2015 (has links)
Thesis (Ph. D. (Criminology)) -- University of Limpopo, 2015 / The research concerned with the aim of this study, was to assess the appli-cation of intelligence-driven investigation in combating organised motor vehicle theft. The strategic intelligence plan, information sharing and understanding of or-ganised vehicle theft, are some of approaches which will assist in dealing with the challenge of the illegal sale of vehicles and vehicle parts. There is indeed a need to address police corruption, if the battle against vehicle theft is to be realised. The objectives of this study were the following: to explain the strategic intelli-gence plan for investigating motor vehicle theft; to evaluate whether investiga-tions of organised motor vehicle theft in Thohoyandou cluster are intelligence-driven; to assess if the cluster uses intelligence offender profiling in investi-gations; to explore how intelligence-driven investigation assists in information sharing; and, to make recommendations for the improvement of intelligence-driven vehicle theft investigation. The researcher wanted to apply new research knowledge, in order to develop good practice in the field. This has been done by recommending new proced-ures to enhance performance and to improve the ways and means of combating organised vehicle theft. KEY TERMS Intelligence-driven investigation; strategic intelligence; intelligence cycle; crime investigations; modus operandi; offender profiling; organised crime; systems theory; motor vehicle theft; information sharing.
177

An assessment of application of intelligence-driven investigation in the combating of organised vehicle theft in Thohoyandou Cluster

Bila, Hlengani Phanuel January 2015 (has links)
Thesis (Ph.D. (Criminology)) -- University of Limpopo, 2015 / The research concerned with the aim of this study, was to assess the appli-cation of intelligence-driven investigation in combating organised motor vehicle theft. The strategic intelligence plan, information sharing and understanding of or-ganised vehicle theft, are some of approaches which will assist in dealing with the challenge of the illegal sale of vehicles and vehicle parts. There is indeed a need to address police corruption, if the battle against vehicle theft is to be realised. The objectives of this study were the following: to explain the strategic intelli-gence plan for investigating motor vehicle theft; to evaluate whether investiga-tions of organised motor vehicle theft in Thohoyandou cluster are intelligence-driven; to assess if the cluster uses intelligence offender profiling in investi-gations; to explore how intelligence-driven investigation assists in information sharing; and, to make recommendations for the improvement of intelligence-driven vehicle theft investigation. The researcher wanted to apply new research knowledge, in order to develop good practice in the field. This has been done by recommending new proced-ures to enhance performance and to improve the ways and means of combating organised vehicle theft. KEY TERMS Intelligence-driven investigation; strategic intelligence; intelligence cycle; crime investigations; modus operandi; offender profiling; organised crime; systems theory; motor vehicle theft; information sharing.
178

Nehodovost mladých řidičů / The Traffic Accident Rate in Young Drivers

Hillebrant, Michael January 2017 (has links)
This diploma thesis is focused at accident rate of young drivers in Czech Republic. First part of the thesis is dedicated to theoretical background where young people psychological behaviors are described. There are also described several specific accidents from expertise point of view. Another part dives into statistics of accidents in the Czech Republic in the last nine years. Last part of the thesis recommends some specific countermeasures for practical implementation.
179

Quantifying Relative Surface Level Brain Motion in Postmortem Human Subjects Using High-Frequency B-Mode Ultrasound

Tesny, Angela Clara 13 September 2022 (has links)
No description available.
180

Booster Seat Use and Child Passenger Safety in Ohio, United States

Li, Li January 2021 (has links)
No description available.

Page generated in 0.0391 seconds