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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.
181

Effects of rear bumper beam deletion on the perception of steering performance of commercial vehicles

Banks, Alan James January 2015 (has links)
In order to remain competitive in the marketplace, all motor vehicle manufacturers face difficult decisions with regard to balancing cost vs. feature. That is to say that the manufacturer must balance the cost of the product to the customer to remain competitive whilst offering appropriate technology and standard features required by that customer. All motor manufacturers are therefore under pressure to keep costs of nonfeature items to a minimum. One of the cost reductions items prevalent on most vehicles is the deletion of the structural member that attaches the rear bumper, known as the bumper beam (RBB), which is researched in this Thesis. This generates average vehicle savings of $20 and, as this is invisible to the customer, should enable the manufacturers to realise a significant saving or allow this revenue to be spent on additional feature without loss of vehicle function. However, in nearly all cases, deletion of the rear bumper beam has the effect of degrading the steering responses of the vehicle by 1 to 1½ rating points (out of 10), which is contrary to the premise of cost reductions; which is to ensure that vehicle function is unaffected. Initial analysis of vehicles with deleted rear bumper beams cannot show an objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the effects of the bumper beam. It was necessary to employ unconventional modelling and testing methods such as rigid body, flexible body model techniques as well as experimental studies included driving robots and expert driver appraisals. The research demonstrated that vehicle modelling methods currently used, cannot establish or predict the complete vehicle ride and handling status. A total vehicle model approach should be used without separating the body CAE model and vehicle dynamics ADAMS model into separate entities. Furthermore, it was concluded that the determination to the effects of body hysteresis rather than pure stiffness is of crucial importance and that the steering attribute could be maintained with the deletion of the RBB analytically.
182

SJUKFÖRSÄKRINGEN OCH POLITIKEN -En kvalitativ studie över styrning och politik kring sjukförsäkringen

Glamsjö, Henrik, Holmberg, Marcus January 2018 (has links)
This essay is about how the government formulates its policy regarding the health insurance and how these ambitions are then translated in the steering of the Swedish Swedish Social Insurance Fund. We have formulated the following questions: ● How is government policy and governance formulated in terms of health insurance? ● How does government policy and governance differ in terms of health insurance policy during the period studied? ● How does government's policy orientation affect the overall governance they provide to the Social Insurance Fund? We also analyze whether there are differences in policy and governance and between governments that took place in 2006, 2010 and 2014. We have read political material such as election manifesto and the Prime ministers´statement of government policy and compared this with the governments appropriation directions to the Swedish Social Insurance Fund and directions in the state budget. For the analysis, we use text analysis and we have, under the results and conclusions, identified two themes that all three governments commute between: the labor theme and the security theme. Our theoretical approach is the theory formulated by Frank Baumgartner och Bryan Jones Punctuated Equilibrium. We find that although there are differences in policy depending on the government's political color, governance is relatively stable. The overall objectives of the Swedish Social Insurance Fund have only been changed once during the period we have studied. In our analysis we have a reasoning for our outcome based on our theoretical perspective.
183

Poder diretivo do empregador e liberdade de expressão do empregado / Power steering employer and the employee freedom of expression.

Dawis Paulino da Silva 04 June 2013 (has links)
Avaliar a forma como interagem o chamado poder diretivo do empregador e a liberdade de expressão do empregado é o desafio que se empreende neste trabalho. Em certa medida, a eleição do tema já revela a adesão deste mestrando à corrente doutrinária que concebe existência de direitos fundamentais trabalhistas, específicos e inespecíficos, no âmbito e no universo das relações de trabalho, no caso do presente estudo, na relação de emprego. Para atingir o escopo proposto quando da escolha do tema, optamos pelo desenvolvimento de um trabalho em 6 capítulos, com análises e estudos, alguns de menor extensão, dado o caráter de coadjuvância com o tema principal, outros de maior extensão, dada a centralidade com a tarefa abraçada. Iniciamos nosso estudo com breves considerações históricas acerca do fenômeno do poder, cuidando do enquadramento conceitual e com abordagem de sua evolução a partir da antiguidade até o sistema capitalista, berço do direito do trabalho (1º Capítulo). Superada a abordagem do poder, genericamente considerado, debruçamos nossa atenção para a análise do poder diretivo de modo mais particular. E aqui tratamos das questões do conceito, fundamento legal e doutrinário, formas de expressão e limitações incidentes (2º Capítulo). O trabalho prossegue e com o propósito de estabelecer uma conexão com o trecho anterior do estudo, dirigimos a análise para a verificação dos direitos e deveres de empregado e empregador para que assim se evidencie potencialidades e limites tanto do poder diretivo do empregador, quanto dos direitos fundamentais do empregado, dentre os quais a liberdade de expressão (3º Capítulo). A sequencia do trabalho contém os esforços para o correto posicionamento da liberdade de expressão dentro do universo dos direitos humanos ou do homem, direitos fundamentais e direitos da personalidade. E com o intuito de melhor posicionar a liberdade de expressão, fazemos uma avaliação dentro do contexto do direito nacional e internacional, bem como abordamos, ainda que com pouca profundidade, a questão das gerações ou dimensões dos direitos fundamentais (4º Capítulo). O trato da liberdade de expressão tematiza o penúltimo capitulo e nele envidamos esforços para localizar em que esfera da existência do trabalhador subordinado, íntima, privada ou pessoal, ou no âmbito de todas estas, está a liberdade de expressão. Neste mesmo capítulo, devotamos nossa análise para a questão do plano de eficácia do direito fundamental à liberdade de expressão inclusive com o debate com a abordagem das formas, objeções, limites da liberdade de expressão e sobretudo com uma análise do direito em debate no contexto da relação de emprego, inclusive no que toca ao chamado direito de crítica. Encerramos esse capitulo com considerações acerca de medidas de proteção em caso de dispensa discriminatória. Na conclusão registramos nossas ponderações. / Assess how named steering power of the employer interacts and the employee\'s freedom of expression is the challenge that this work is undertaken. To some extent, the election theme already reveals the accession of the current Master\'s doctrinal conceives existence of fundamental labor, specific and nonspecific, and within the universe of labor relations in the case of this study, the employment relationship. To achieve the proposed scope when choosing the theme, we opted for the development of a work in 6 chapters, with analyzes and studies, some less extensive, given the character of co-acting with the main subject, other larger extent, given the centrality and embraced the task. We begin our study with brief historical considerations about the phenomenon of power, taking care of the conceptual framework and approach of its evolution from antiquity to the capitalist system, the cradle of labor law (Chapter 1). Approach to overcome the power, generally considered, worked through our attention to the analysis of power steering more particular. And here we treat the issues of concept, doctrinal and legal basis, forms of expression and limitations incidents (Chapter 2). The work continues in order to establish a connection with the earliest part of the study, headed analysis to verify the rights and duties of employee and employer so that if evidence of both potential and limits of the directive power of the employer, as rights key employee, among which the freedom of expression (Chapter 3). The sequence of this work includes efforts to the correct positioning of freedom of expression within the universe of human rights or of man, fundamental rights and personality rights. And in order to better position the freedom of speech, we make an assessment within the context of national and international law, as well as approach, albeit with little depth, the issue of generational dimensions or fundamental rights (Chapter 4). The tract of freedom of expression lead the penultimate chapter and we strive to find it in that sphere of existence of subordinate worker, intimate, private or personal, or under all these, is the freedom of expression. In this same chapter, we devote our analysis to the question of plan effectiveness of the fundamental right to freedom of expression and ended the debate with the approach of the ways, objections, limits of freedom of expression and especially the analysis of law in the context of the debate employment relationship, including with regard to the so-called right of criticism. In conclusion we recorded our weightings.
184

A general methodology for generating representative load cycles for monohull surface vessels

Truelove, William Anthony Lawrence 19 December 2018 (has links)
In this thesis, a general methodology for generating representative load cycles for arbitrary monohull surface vessels is developed. The proposed methodology takes a hull geometry and propeller placement, vessel loading condition, vessel mission, and weather data (wind, waves, currents) and, from that, generates the propeller states (torque, speed, power) and steering gear states (torque, speed, power) necessary to accomplish the given mission. The propeller states, together with the steering gear states, thus define the load cycle corresponding to the given inputs (vessel, mission, weather). Some key aspects of the proposed methodology include the use of a surge-sway-yaw model for vessel dynamics as well as the use of surrogate geometries for both the hull and propeller(s). What results is a methodology that is lean (that is, it requires only sparse input), fast, easy to generalize, and reasonably accurate. The proposed methodology is validated by way of two separate case studies, case A and case B (both involving distinct car-deck ferries), with case A being a more ideal case, and case B being a less ideal case given the methodology proposed. In both cases, the load cycle generation process completed in greater than real time, achieving time ratios (simulated time to execution time) of 3.3:1 and 12.8:1 for cases A and B respectively. The generated propeller and steering gear states were then compared to data collected either at sea or from the vessels' documentation. For case A, the propeller speed, torque, and power values generated were all accurate to within +/- 3%, +/- 7%, and +/- 10% of the true values, respectively, while cruising, and accurate to within +/- 14%, +/- 36%, and +/- 42% of the true values, respectively, while maneuvering. In addition, the steering gear powers generated in case A were consistent with the capabilities of the equipment actually installed on board. For case B, the propeller speed, torque, and power values generated were all accurate to within +/- 2%, +/- 8%, and +/- 9% of the true values, respectively, while cruising, and accurate to within +/- 28%, +/- 45%, and +/- 66% of the true values, respectively, while maneuvering. In case B, however, the steering gear powers generated were questionable. Considering the results of the validation, together with the rapid process runtimes achieved and sparse inputs given, one may conclude that the methodology proposed in this thesis shows promise in terms of being able to generate representative load cycles for arbitrary monohull surface vessels. / Graduate
185

Comparativo de empenamento e microestrutural em cremalheiras de aço SAE 1045 temperadas por indução e por condução / Comparison of warpage and microstructure in SAE 1045 steel racks quenched by induction and by conduction

Amaral, Regis Fabiano do January 2016 (has links)
A microestrutura de uma peça temperada determina suas características mecânicas. Dessa forma, torna-se fundamental conhecer os parâmetros que influenciam na formação da estrutura do componente tratado com função dos tratamentos térmicos aplicados, permitindo obter melhorias de qualidade de uma peça frente a sua aplicação. Métodos distintos podem ser empregados para obtenção da camada de têmpera. Entretanto, esses métodos devem ser parametrizados adequadamente para garantir a qualidade do produto final. No trabalho em questão, aplicaram-se dois metódos distintos de têmpera: por indução e por condução para obtenção da camada martensítica, dureza e durabilidade requerida em cremalheiras de aço SAE 1045, utilizadas em mecanismo de direção automotiva. Fabricou-se um lote de peças, do qual metade das peças foram tratadas por indução e a outra por condução. Após a têmpera e após o revenido, foi avaliado o nível de empenamento, a dureza superficial, a microdureza, a microestrutura formada. A peças após o término do processo de fabricação, foram montadas no sistema caixa de direção, sendo realizados ensaios de durabilidade e impacto dos mesmos. Os tratamentos realizados demonstraram resultados de empenamento, dureza, microestrutura e ensaios de durabilidade e impacto no produto final, dentro das especificações. O processo de têmpera por condução levou a melhor micrestrutura, mais alta dureza e menores níveisde empenamento comparado com o processo de têmpera por indução. Mas, também constatou-se que é possível desenvolver melhorias no processo de indução para atingir-se resultados melhores. / The microstructure of a hardened part is determining its mechanical characteristiscs. Thus, the knowledge of pararameters influencing the heat treated part’s microstructure is of fundamental importance. This allows to obtain quality improvements for specific applications. Diferent methods can be used for the obtation of a hardened layer. However, in these methods the parameters have to be correctly set to reach the final product quality. In this work, two diferente techniques were applied, induction and conduction surface hardening to obtain a required martensitic layer depth, hardness and durability of SAE 1045 steel racks used in automotive driving systems. A batche of parts were manufactured, being half of the parts surface hardened by Induction and half by conduction. After hardening and after tempering, the warpage level, surface hardness, microhardness and microstructure were investigated. The parts were mounted in a steering gear system and then endurance tests and impact tests were carried out. The results of warpage levels, hardness, microstructure and endurance tests, as well as the impact tests were in the range of the specifications. The conduction hardening process leads to better microstructure, higher hardness and lower warpage levels compared to induction hardening. But it was found that the Induction hardening can be optimized to reach better results.
186

Konstrukce řízení vozidla - Elbee / Vehicle Steering System Design - Elbee

Crhová, Hana January 2015 (has links)
The aim of the diploma thesis is a proposal of a new steering construction of the special vehicle for disabled. The fundamental requirement for new construction is driving by only one main control. New steering construction was designed to uses drive-by-wire method and the vehicle is controlled by joy-stick. The proposal and necessary calculations were performed using Autodesk Inventor Professional 2015 software.
187

Otimização do comportamento dinâmico lateral e vertical de um ônibus modelado como sistema multicorpo

Pavan, Leandro January 2015 (has links)
Existe necessidade de se desenvolver modelos teóricos e testes experimentais, que nos permitam ter plenas condições de melhor avaliar e concluir sobre o comportamento dinâmico dos ônibus, ao trafegar sobre diferentes pistas e realizar diversos tipos de manobras. O objetivo do trabalho é avaliar e otimizar simultaneamente o comportamento dinâmico lateral e vertical de um ônibus modelado como um sistema multicorpo. A metodologia utilizada no trabalho é dividida em duas partes. A primeira parte consiste na programação de um modelo multicorpo de ônibus que possa ser utilizado para fins de otimização do seu comportamento de dinâmica lateral via programação matemática; o desenvolvimento de uma manobra do tipo mudança dupla de faixa - DLC (Double Lane Change), adaptada da combinação da norma ISO 3888-1:1999 que envolve mudança dupla de faixa para carros de passeio e a norma ISO 14791:2000 que envolve mudança simples de faixa para veículos comerciais, na ausência de normas específicas; e finalmente a validação de resultados através de testes experimentais e simulações computacionais. A segunda parte consiste na programação de um modelo multicorpo de ônibus para fins de otimização do seu comportamento de dinâmica vertical via programação matemática, neste caso sujeito a uma pista da classe C segundo classificação da norma ISO 8608:1995. Os resultados específicos da programação das manobras laterais do modelo de ónibus foram validados experimentalmente, bem como comparados através da simulação das manobras num modelo virtual implementado num software multicorpo comercial. O conjunto das soluções atingidas mostraram boa correlação, possibilitando a posterior otimização dos parâmetros concentrados da suspensão do modelo multicorpo de ônibus, através da técnica de algoritmos genéticos. A função objetivo implementada consiste da composição penalizada do valor RMS do ângulo de rolagem da manobra lateral quanto ao handling, e de parâmetros associados ao conforto e segurança, como o valor RMS da aceleração vertical, do deslocamento máximo da suspensão, e da deflexão máxima do pneu de forma a garantir aderência continua à pista. Os resultados otimizados dos parâmetros concentrados conseguem uma negociação dos objetivos conflitantes. / There is a need for theoretical models and experimental tests to be developed that allow for better assessments and conclusions about the dynamic behavior of buses driving on different lanes and performing various types of maneuvers. The purpose of this work is to evaluate and optimize both the lateral and the vertical dynamic behavior of a bus modeled as a multibody system. The methodology employed comprises two parts. The first part consists in programming a bus multibody model that can be used to optimize the lateral dynamic behavior of buses via mathematical programming; developing a type of maneuver known as Double Lane Change (DLC), adapted from a combination of the ISO 3888-1:1999 standard, which involves double lane changes for passenger cars, and the ISO 14791:2000 standard, which involves single lane changes for commercial vehicles, in the absence of specific standards; and lastly, validating the results by means of experimental tests and computational simulations. The second part consists in programming a bus multibody model to optimize the vertical dynamic behavior via mathematical programming, in this case for a class C road, according to the classification of the ISO 8608:1995 standard. The specific results of the programming of the lateral maneuvers of the bus model were validated experimentally and then compared with simulations of the maneuvers by a virtual model developed using commercial multibody software. The results showed a good correlation, enabling subsequent optimization of the lumped parameters of the suspension of the bus multibody model using the genetic algorithm optimization technique. The objective function consists of the penalized composition of some terms, including the RMS value of the roll angle of the lateral handling maneuver and of parameters associated with comfort and safety, such as the RMS value of vertical acceleration, the maximum suspension working space, and the maximum tire deflection to ensure continuous adherence on the road surface. The optimized results of the lumped parameters of the suspension enable an alignment of the conflicting goals.
188

Stanovení poloměru otáčení u traktorů Zetor Forterra 140 HSX, Zetor Proxima 120 Power a Zetor 7745 Turbo pro potřeby počítačových modelů

ZLOCH, Jan January 2018 (has links)
The main aim of this diploma thesis is to determine the radius of rotation of selected tractors (Zetor Forterra 140 HSX, Zetor Proxima 120 Power and Zetor 7745 Turbo) on three different types of surfaces using different speeds. The literary part deals briefly with the importance and historical development of tractors, the basic knowledge of traction theory, the problems of forces acting on the rolling wheel, and last but not least the construction of the tractor parts. The practical part is mainly focused on determining the radii of rotation of individual tractors on three specified types of surfaces using the three given speeds. The discussion is mainly focused on comparing the radii of rotation meeting ČSN 30 0552 with the radii given by the tractor manufacturer.
189

Metodologia para ensaio de sistemas de direcionamento via satélite em percursos retos e curvos

Baio, Fábio Henrique Rojo [UNESP] 18 July 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07-18Bitstream added on 2014-06-13T21:02:54Z : No. of bitstreams: 1 baio_fhr_dr_botfca.pdf: 1752320 bytes, checksum: 5f5df0d06b9f3f74819e53ed595378e2 (MD5) / Universidade Estadual Paulista (UNESP) / O uso do Sistema de Posicionamento Global (GPS) em uma propriedade agrícola não está limitado ao monitoramento georreferenciado de fatores produtivos, mas cada vez mais esta tecnologia está sendo utilizada como um equipamento disponível dentro da propriedade e que deve ser utilizada o máximo possível para a diluição do seu custo. Uma utilização cotidiana desta tecnologia é em sistemas de direcionamento via satélite. No entanto, ensaios destes sistemas de direcionamento operando em curva estão ainda no início. Poucas também são as informações relacionadas à análise de custo de investimento desta tecnologia. Os objetivos deste trabalho foram desenvolver uma metodologia de campo para ensaios de sistemas de direcionamento via satélite e/ou convencionais em sua utilização terrestre operando em reta e em curva, avaliar a acurácia de diferentes sistemas de orientação seguindo a metodologia desenvolvida e realizar uma breve análise de investimento para aquisição de um sistema de direcionamento via satélite. Para tanto, foram realizados quatro ensaios de campo em que foram ensaiados sete sistemas de direcionamento por barra de luz, um sistema de auto-direcionamento, um sistema de direcionamento por monitor eletrônico, um sistema de direcionamento por cabo-de-aço e um sistema de orientação por marcador de espuma. Em cada ensaio de campo foi aplicada a mesma metodologia desenvolvida para avaliação da acurácia destes sistemas de direcionamento. Esta metodologia se baseou na mensuração direta em campo dos desvios dos alinhamentos orientados pelos sistemas de direcionamento em relação ao alinhamento programado. Os ensaios foram realizados em reta e em curva. A metodologia de campo apresentada neste trabalho para ensaios de sistemas de direcionamento pôde ser aplicada com sucesso... / The use of the Global Positioning System (GPS) in a farm is not limited to monitor productive factors involved on the yield production, but the GPS have been used as equipment available into the farm that can be used to another issues and it must be used a lot into the farm to dilute the initial cost. A daily use of this technology is on steering systems. However, we do not have results of field tests of these steering systems operating in curve. Few also are the information related to the cost analysis of investments on this technology. The purposes of this work were develop a field test methodology to evaluate the accuracy of conventional steering systems and/or satellites steering systems operating in straight line or curve operations, evaluate the accuracy of several steering systems according to the developed methodology and perform a brief cost analysis to buy a satellite steering system. Four field test evaluations were performed where were evaluated seven light bar steering systems, one auto-steering system, one steering system operated by an electronic monitor, a steering system operated by a steel cable and a system oriented by a foam marker. The same developed methodology was applied on these four field test. This developed methodology was based on measure the steering error compared to the programmed alignment directly on the field, where an operator was guided by the evaluated steering system. The tests were made in straight line and curve operations. The field methodology presented in this work was successful. The advantage of this methodology is the possibility of reflection of all factors involved in the errors and the possibility of the errors measured in the field directly by the final user...(Complete abstract click electronic access below)
190

Design and Calibration of a 12-Bit Current-Steering DAC Using Data-Interleaving

January 2014 (has links)
abstract: High speed current-steering DACs with high linearity are needed in today's applications such as wired and wireless communications, instrumentation, radar, and other direct digital synthesis (DDS) applications. However, a trade-off exists between the speed and resolution of Nyquist rate current-steering DACs. As the resolution increases, more transistor area is required to meet matching requirements for optimal linearity and thus, the overall speed of the DAC is limited. In this thesis work, a 12-bit current-steering DAC was designed with current sources scaled below the required matching size to decrease the area and increase the overall speed of the DAC. By scaling the current sources, however, errors due to random mismatch between current sources will arise and additional calibration hardware is necessary to ensure 12-bit linearity. This work presents how to implement a self-calibration DAC that works to fix amplitude errors while maintaining a lower overall area. Additionally, the DAC designed in this thesis investigates the implementation feasibility of a data-interleaved architecture. Data interleaving can increase the total bandwidth of the DACs by 2 with an increase in SQNR by an additional 3 dB. The final results show that the calibration method can effectively improve the linearity of the DAC. The DAC is able to run up to 400 MSPS frequencies with a 75 dB SFDR performance and above 87 dB SFDR performance at update rates of 200 MSPS. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2014

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