• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 5
  • 5
  • Tagged with
  • 22
  • 22
  • 7
  • 7
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 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

Semi-autonomous robotic wheelchair controlled with low throughput human- machine interfaces

Sinyukov, Dmitry Aleksandrovich 01 May 2017 (has links)
For a wide range of people with limited upper- and lower-body mobility, interaction with robots remains a challenging problem. Due to various health conditions, they are often unable to use standard joystick interface, most of wheelchairs are equipped with. To accommodate this audience, a number of alternative human-machine interfaces have been designed, such as single switch, sip-and-puff, brain-computer interfaces. They are known as low throughput interfaces referring to the amount of information that an operator can pass into the machine. Using them to control a wheelchair poses a number of challenges. This thesis makes several contributions towards the design of robotic wheelchairs controlled via low throughput human-machine interfaces: (1) To improve wheelchair motion control, an adaptive controller with online parameter estimation is developed for a differentially driven wheelchair. (2) Steering control scheme is designed that provides a unified framework integrating different types of low throughput human-machine interfaces with an obstacle avoidance mechanism. (3) A novel approach to the design of control systems with low throughput human-machine interfaces has been proposed. Based on the approach, position control scheme for a holonomic robot that aims to probabilistically minimize time to destination is developed and tested in simulation. The scheme is adopted for a real differentially driven wheelchair. In contrast to other methods, the proposed scheme allows to use prior information about the user habits, but does not restrict navigation to a set of pre-defined points, and parallelizes the inference and motion reducing the navigation time. (4) To enable the real time operation of the position control, a high-performance algorithm for single-source any-angle path planning on a grid has been developed. By abandoning the graph model and introducing discrete geometric primitives to represent the propagating wave front, we were able to design a planning algorithm that uses only integer addition and bit shifting. Experiments revealed a significant performance advantage. Several modifications, including optimal and multithreaded implementations, are also presented.
12

Learning physics in a Taiwanese college classroom: a constructivist perspective

Ying, Wai Tsen January 2008 (has links)
The purpose of this study is to use a constructivism as a referent to investigate how students learn physics in a Taiwanese career college classroom. Forty-nine first year, engineering major first students participated in this study of teaching and learning in my college level classroom. The theoretical framework for the study was based on the five dimensions of the Constructivist Learning Environment Survey (CLES) (Taylor & Fraser, 1991: Taylor, Fraser & White, 1994; Taylor, Fraser & Fisher, 1997), namely Personal Relevance, Student Negotiation, Shared Control, Critical Voice, and Uncertainty. These dimensions were employed as analytic themes to examine the qualitative data. / A total of six lessons were observed: two lecture classes, two laboratory practice sessions, and two group discussion sessions. My qualitative observations, supplemented by video- and audio-recordings, of these six lessons were used to produce six classroom narratives. These six narratives were analyzed individually and then comparatively using a cross case analysis whereby the five dimensions of the CLES were employed as analytic themes. The CLES questionnaire was administered at the commencement of the semester and again at the end of the semester in order to determine any quantitative changes in students’ perceptions of their classroom environment. The various analyses were used to make several propositions about the constructivist nature of my classroom. I conclude the study with a discussion of the implications of the study and my reflections on the thesis experience. / The study found that, in my Taiwanese career college physics classroom, (a) the teacher plays a central role in establishing the overall classroom learning environment, (b) student group dynamics are important in the classroom learning environment, (c) the central role of content often works against the establishment of a constructivist classroom, (d) cultural factors play a large role in determining the constructivist nature of the classroom, (e) language plays an important role in the construction of the learning environment, and (f) the students’ learning attitude affected the classroom environment.
13

Por que as tarifas de interconexão são tão altas? Um modelo de competição entre telefonia fixa e móvel

Lima, Lucas Ferreira Matos 24 February 2014 (has links)
Submitted by Lucas Ferreira Matos Lima (lucas.lima@gvmail.br) on 2014-03-19T23:24:33Z No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2014-03-20T16:34:02Z (GMT) No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) / Made available in DSpace on 2014-03-20T17:53:56Z (GMT). No. of bitstreams: 1 Lucas.Dissertação.pdf: 1006691 bytes, checksum: 0cdbda535e7d2b8e4027523c167ae00f (MD5) Previous issue date: 2014-02-24 / There is a puzzle between the literature of competition of telecommunication networks and the reality. The first one has as the main result that the mobile termination rates will be set bellow the marginal cost to end a call. But the reality shows that the mobile termination rates are too high and the regulators faces a lot of constrains when they try to bring down the level of those rates, because the mobile networks oppose to those policies. This work develops a model based on Hoernig (2010) that presents more realistic results. It will use a new assumption: the mobile networks will compete at the same market with a fixed network and this last one will have its prices regulated. This is a plausible assumption considering the actual development of the mobile networks. The model has two frameworks: at the first there is any kind of shared control between one of the mobile and fixed telephony, but at the second that shared control exists. Because of the assumption that the mobile and fixed networks will compete, this work has as general result that the mobile networks will set the mobile termination rates above the marginal cost of terminating a call. / Existe uma dissonância entre a teoria dominante de competição entre telefonias e evidências empíricas. Aquela tem como resultado que as redes de telefonia móvel irão definir a tarifa de interconexão abaixo do custo marginal de término da ligação. Já evidências empíricas diversas mostram que as tarifas de interconexão das telefonias móveis são mais elevadas e que as agências reguladoras encontram resistência destas ao aplicarem políticas de redução das tarifas de interconexão. Este trabalho desenvolve um modelo, baseado em Hoernig (2010), que provê resultados mais aderentes às evidências de existência de incentivos para precificação de tarifas de interconexão acima do custo marginal. O modelo aqui proposto inova em relação a Hoernig (2010) ao assumir que as redes de telefonia móvel concorrem com a telefonia fixa, a qual é sujeita à regulação da tarifa de interconexão. Esta é uma representação bastante plausível frente ao desenvolvimento da telefonia móvel. O modelo também considera o efeito de uma das empresas de telefonia móvel ter o seu controle compartilhado com a de telefonia fixa. Devido ao pressuposto de competição em um mesmo mercado entre telefonia fixa e móvel, é encontrado como resultado geral que as redes de telefonia móvel irão definir a tarifa de interconexão acima do custo marginal de término da ligação.
14

Models, algorithms and architectures for cooperative manipulation with aerial and ground robots / Modèles, algorithmes et architectures pour la manipulation coopérative entre robots au sol et aériens

Staub, Nicolas 17 January 2018 (has links)
Les dernières années ont vu le développement de recherches portant sur l'interaction physique entre les robots aériens et leur environnement, accompagné de l'apparition de nombreux nouveaux systèmes mécaniques et approches de régulation. La communauté centrée autour de la robotique aérienne observe actuellement un déplacement de paradigmes des approches classiques de guidage, de navigation et de régulation vers des tâches moins triviales, telle le développement de l'interaction physique entre robots aériens et leur environnement. Ceci correspond à une extension des tâches dites de manipulation, du sol vers les airs. Cette thèse contribue au domaine de la manipulation aérienne en proposant un nouveau concept appelé MAGMaS, pour " Multiple Aerial Ground Manipulator System ". Les motivations qui ont conduites à l'association de manipulateurs terrestres et aériens pour effectuer des tâches de manipulation coopérative, résident dans une volonté d'exploiter leurs particularités respectives. Les manipulateurs terrestres apportant leur importante force et les manipulateurs aériens apportant leur vaste espace de travail. La première contribution de cette thèse présente une modélisation rigoureuse des MAGMaS. Les propriétés du système ainsi que ses possibles extensions sont discutées. Les méthodes de planning, d'estimation et de régulation nécessaire à l'exploitation des MAGMaS pour des tâches de manipulation collaborative sont dérivées. Ce travail propose d'exploiter les redondances des MAGMaS grâce à un algorithme optimal d'allocation de forces entre les manipulateurs. De plus, une méthode générale d'estimation de forces pour robots aériens est introduite. Toutes les techniques et les algorithmes présentés dans cette thèse sont intégrés dans une architecture globale, utilisée à la fois pour la simulation et la validation expérimentale. Cette architecture est en outre augmentée par l'addition d'une structure de télé-présence, afin de permettre l'opération à distances des MAGMaS. L'architecture générale est validée par une démonstration de levage de barre, qui est une application représentative des potentiels usages des MAGMaS. Une autre contribution relative au développement des MAGMaS consiste en une étude exploratoire de la flexibilité dans les objets manipulés par un MAGMaS. Un modèle du phénomène vibratoire est dérivé afin de mettre en exergue ses propriétés en termes de contrôle. La dernière contribution de cette thèse consiste en une étude exploratoire sur l'usage des actionneurs à raideur variable dans les robots aériens, dotant ces systèmes d'une compliance mécanique intrinsèque et de capacité de stockage d'énergie. Les fondements théoriques sont associés à la synthèse d'un contrôleur non-linéaire. L'approche proposée est validée par le biais d'expériences reposant sur l'intégration d'un actionneur à raideur variable léger sur un robot aérien. / In recent years, the subject of physical interaction for aerial robots has been a popular research area with many new mechanical designs and control approaches being proposed. The aerial robotics community is currently observing a paradigm shift from classic guidance, navigation, and control tasks towards more unusual tasks, for example requesting aerial robots to physically interact with the environment, thus extending the manipulation task from the ground into the air. This thesis contributes to the field of aerial manipulation by proposing a novel concept known has Multiple Aerial-Ground Manipulator System or MAGMaS, including what appears to be the first experimental demonstration of a MAGMaS and opening a new route of research. The motivation behind associating ground and aerial robots for cooperative manipulation is to leverage their respective particularities, ground robots bring strength while aerial robots widen the workspace of the system. The first contribution of this work introduces a meticulous system model for MAGMaS. The system model's properties and potential extensions are discussed in this work. The planning, estimation and control methods which are necessary to exploit MAGMaS in a cooperative manipulation tasks are derived. This works proposes an optimal control allocation scheme to exploit the MAGMaS redundancies and a general model-based force estimation method is presented. All of the proposed techniques reported in this thesis are integrated in a global architecture used for simulations and experimental validation. This architecture is extended by the addition of a tele-presence framework to allow remote operations of MAGMaS. The global architecture is validated by robust demonstrations of bar lifting, an application that gives an outlook of the prospective use of the proposed concept of MAGMaS. Another contribution in the development of MAGMaS consists of an exploratory study on the flexibility of manipulated loads. A vibration model is derived and exploited to showcase vibration properties in terms of control. The last contribution of this thesis consists of an exploratory study on the use of elastic joints in aerial robots, endowing these systems with mechanical compliance and energy storage capabilities. Theoretical groundings are associated with a nonlinear controller synthesis. The proposed approach is validated by experimental work which relies on the integration of a lightweight variable stiffness actuator on an aerial robot.
15

Solutions robotiques bas coût pour l’aide à la navigation en fauteuil roulant électrique : vers une contribution dans le champ de la rééducation neurologique / Low-cost robotic solutions for safe assisted power wheelchair navigation : towards a contribution to neurological rehabilitation

Devigne, Louise 06 December 2018 (has links)
Alors que l’utilisation d’un fauteuil roulant permet aux personnes en situation de handicap de compenser une perte de la mobilité, certaines personnes se voient privées de l’utilisation d’un fauteuil roulant électrique. En effet, la présence de troubles cognitifs ou de la perception visuelle altère la capacité à conduire sans danger. Dans ce contexte, l’accès à la mobilité peut être amélioré par l’apport d’aides techniques adaptées permettant de compenser la perte de mobilité dans tous types d’environnements. Alors que les premiers travaux sur les fauteuils roulants intelligents datent du début des années 80, aucune solution n’est à ce jour sur le marché ou dans les centres de rééducation. Ce travail vise à proposer un ensemble de solutions d’aide à la conduite de fauteuil roulant électrique conçu en collaboration. Le développement de telles aides techniques constitue de multiples défis robotiques mêlant techniques de détection innovantes et méthodes de contrôle partagé avec l’utilisateur. Dans ce travail, un simulateur de conduite visant à appuyer la recherche et le développement de nouvelles solutions robotiques est proposé. Puis des solutions bas coût d’assistance semiautonome à la conduite en intérieur et en extérieur sont détaillées. L’évaluation avec des participants sains nous permet de valider les méthodes mathématiques mises en oeuvre et de fournir des preuves de concept des solutions proposées. Enfin, les premières évaluations cliniques avec des usagers au Pôle MPR Saint Hélier montrent la validation de de la méthode proposée en termes de satisfaction des utilisateurs. / While the use of a wheelchair allows people with disabilities to compensate for a loss of mobility, people with severe disabilities are denied the use of a power wheelchair. Indeed, cognitive or visual perception impairments can affect the ability to drive safely. In this context, access to mobility can be improved by providing appropriate assistive technologies to compensate for loss of mobility in all types of environments. While the first research on smart wheelchairs dates back to the early 1980s, no solutions have yet been proposed on the market or in rehabilitation centers and other specialized structures. This work aims to propose a set of solutions for power wheelchair navigation assistance designed in close collaboration with users and therapists. The development of such assistive solutions faces multiple robotic challenges combining innovative detection techniques, shared control with the user. In this work, a driving simulator supporting research and development of new robotic solutions for wheelchair navigation assistance is proposed. Then low-cost semi-autonomous assistance solutions for navigation assistance in indoor and outdoor environments are detailed. The evaluation with able-bodied participants allows to validate the mathematical methods and provide proof of concept of the proposed solutions. Finally, the first clinical evaluations with regular users at Pôle MPR Saint Hélier show the validation of the proposed framework in terms of user satisfaction.
16

Sobre o controle minoritário nas companhias listadas no novo mercado / About the minority control in companies listed in the New Market segment

Martes, Camilla Ribeiro 06 June 2014 (has links)
Dentre os atuais desafios do direito societário brasileiro, a estrutura da propriedade acionária das sociedades por ações de capital aberto e a identificação daqueles que as comandam merecem destaque. O aquecimento das transações realizadas via mercado de capitais e a consolidação dos segmentos especiais de governança corporativa no Brasil resultaram no chamado fenômeno de dispersão acionária, que evidenciou certa ruptura na tradicional estrutura de propriedade acionária exclusivamente concentrada, até então predominante nas companhias brasileiras. Diante desse cenário contrastante, de mudanças no perfil do poder de controle sobre as companhias brasileiras, o presente trabalho apresentará em seu capítulo terceiro, após breve análise das estruturas de capital identificadas em diferentes economias e de retrospectiva sobre a propriedade acionária das companhias brasileiras (a serem apresentadas em seu segundo capítulo), extensa pesquisa empírica realizada com o propósito de identificar a atual estrutura de propriedade acionária predominante entre as companhias brasileiras listadas no segmento especial do Novo Mercado da BMF&BOVESPA (Novo Mercado), e com o objetivo de averiguar a existência do chamado controle societário minoritário entre tais companhias, conforme detalhado nos apêndices desta dissertação. Referida pesquisa empírica representa, ainda, rico processamento da base de dados e informações divulgadas à Comissão de Valores Mobiliários (CVM) pelas companhias listadas no Novo Mercado, e serve de base para a avaliação da necessidade de eventuais mudanças nos conceitos adotados pelo Direito Societário pátrio, tendo em vista entendimento divergente identificado na doutrina e em julgados da CVM no âmbito da possibilidade de existência de um controle societário exercido por acionista ou grupo de acionistas não detentores da maioria do capital social votante, conforme detalhado no quarto capítulo deste estudo. Por fim, serão apresentadas, no quinto e último capítulo, as considerações finais à análise proposta, com destaque para as principais conclusões obtidas na elaboração dos capítulos terceiro e quarto descritos acima, dentre elas a existência do controle societário interno não majoritário (controle minoritário) entre companhias listadas no Novo Mercado, bem como os reflexos dessa constatação no âmbito da prática do Direito Societário. / Among the current challenges of the Brazilian Corporate Law, the structure of the capital ownership of the corporations and the identification of those who exercises control over it remains an important aspect to be taken into consideration when analyzing the main aspects of the Brazilian capital market. The heat up of the transactions carried out through the capital market, and the consolidation of the special corporate governance segments in Brazil resulted in the so called phenomenon of the dispersed ownership, which revealed a rupture from the traditional structure of extremely concentrated ownership, that was prevailing until now among the Brazilian corporations. Given such contrasting scenario of changes in the profile of corporate power over Brazilian corporations, these thesis, after describing, over its first two chapters, the structures of capital ownership existent in different economies and providing a retrospective on the capital ownership of Brazilian corporations, presents, in its third chapter, an extensive empirical research performed with the purposes of identifying the current structure of capital ownership prevailing among the Brazilian companies listed in the Novo Mercado, special segment of the Brazilian Exchange BMF&BOVESPA (the New Market), as well as ascertaining the existence of minority corporate control among such companies, as detailed in the appendixes hereto. The referred empirical research presents, furthermore, detailed data processing in connection with the information disclosed by such companies to the Brazilian Stock Exchange Commission, the Comissão de Valores Mobiliários (CVM), and is also used as basis for reviewing the need of eventual changes in the concepts embodied by the Brazilian Corporate Law, in view of the divergent understanding identified in the Brazilian doctrine and judgments issued by the CVM in connection with the existence of a corporate control exercised by a shareholder or group of shareholders owner of shareholding not representative of the majority of the voting capital stock, as detailed in the fourth chapter of these thesis. Finally, the fifth and last chapter of these study presents the final considerations in connection with the review proposed hereto, highlighting the main conclusions obtained through the elaboration of the third and fourth chapters described above, among them the existence of a not majority internal control (minority control) in companies listed in the New Market, as well as the effects of such conclusion in the light of the practice of corporate law.
17

Controle acionário compartilhado e solução de impasses: estudo de caso da Companhia Brasileira de Distribuição

Neves, Lara Britto de Almeida Domingues 25 August 2016 (has links)
Submitted by LARA BRITTO (lara@fiedra.com.br) on 2016-10-17T19:22:28Z No. of bitstreams: 3 Lara Britto -Depósio final - após ajustes 2.pdf: 2009370 bytes, checksum: c0710f4f915c2b23fa13be85a076b637 (MD5) Anexo I - CONTRATO_ACORDO DE ASSOCIAÇÃO.pdf: 5491476 bytes, checksum: b4e40f510f19709b3bd2caf05130ede9 (MD5) Anexo II - Acordo de Acionistas.pdf: 3510200 bytes, checksum: 5ed7f246cdedfbd6bb43101b43949cd1 (MD5) / Approved for entry into archive by Joana Martorini (joana.martorini@fgv.br) on 2016-10-18T12:07:48Z (GMT) No. of bitstreams: 3 Lara Britto -Depósio final - após ajustes 2.pdf: 2009370 bytes, checksum: c0710f4f915c2b23fa13be85a076b637 (MD5) Anexo I - CONTRATO_ACORDO DE ASSOCIAÇÃO.pdf: 5491476 bytes, checksum: b4e40f510f19709b3bd2caf05130ede9 (MD5) Anexo II - Acordo de Acionistas.pdf: 3510200 bytes, checksum: 5ed7f246cdedfbd6bb43101b43949cd1 (MD5) / Made available in DSpace on 2016-10-18T13:52:29Z (GMT). No. of bitstreams: 3 Lara Britto -Depósio final - após ajustes 2.pdf: 2009370 bytes, checksum: c0710f4f915c2b23fa13be85a076b637 (MD5) Anexo I - CONTRATO_ACORDO DE ASSOCIAÇÃO.pdf: 5491476 bytes, checksum: b4e40f510f19709b3bd2caf05130ede9 (MD5) Anexo II - Acordo de Acionistas.pdf: 3510200 bytes, checksum: 5ed7f246cdedfbd6bb43101b43949cd1 (MD5) Previous issue date: 2016-08-25 / This master's thesis aims at investigating the corporate shared control, specifically about potential deadlocks in corporate decisions that might occur due to the corporation’s share distribution structure, it’s organizational structure, or contractual arrangements undertaken by parties. The approach to the subject comes from the study of a real case (the case of the Companhia Brasileira de Distribuição). The research starts with the systematization of case data, a critical assessment of how the Company control shared between Abilio Diniz group and Casino group was structured, in 2005, from the point of view of form and content. The study aims to extract lessons, with generalization potential, on mechanisms for breaking deadlock where business dispute has arisen because there is no consensus in decision making. Part I is descriptive, and aims to make the reader aware of the context of the negotiation transactions and the proposal of shared control by the major shareholders, that was concentrated in two agreements: a 'joint venture agreement' and a 'shareholder’s agreement'. Part II has an analytical purpose and seeks to compare actual data vis-a-vis theoretical positions as it is found in the legal literature. / A presente dissertação de mestrado tem por objetivo investigar o compartilhamento de controle societário, especificamente em relação a possíveis impasses nas deliberações sociais suscetíveis de sobrevir em decorrência da composição societária, estrutura organizacional, ou mecanismos contratuais eleitos pelas partes. A abordagem é à luz de um estudo de um caso real (caso da Companhia Brasileira de Distribuição). Busca-se, então, a partir da sistematização de dados do caso, uma avaliação crítica sobre como foi estruturado, no ano de 2005, o compartilhamento de controle dessa Companhia entre o grupo de Abilio Diniz e o grupo Casino, do ponto de vista da forma e do conteúdo. O estudo direciona-se para lições, com potencial de generalização, sobre procedimentos de resolução de impasses em deliberações de órgãos de administração da sociedade quando, exigido o consenso, não há consenso no processo decisório. A Parte I do trabalho é descritiva, e objetiva inteirar o leitor do contexto da transação negocial e da proposta de compartilhamento entre os dois grupos, resumidamente concentrada em dois instrumentos contratuais: um acordo de associação e um acordo de acionistas. A Parte II tem finalidade analítica e busca contrapor dados reais do caso vis-a-vis posições teóricas encontradas na literatura jurídica.
18

Sobre o controle minoritário nas companhias listadas no novo mercado / About the minority control in companies listed in the New Market segment

Camilla Ribeiro Martes 06 June 2014 (has links)
Dentre os atuais desafios do direito societário brasileiro, a estrutura da propriedade acionária das sociedades por ações de capital aberto e a identificação daqueles que as comandam merecem destaque. O aquecimento das transações realizadas via mercado de capitais e a consolidação dos segmentos especiais de governança corporativa no Brasil resultaram no chamado fenômeno de dispersão acionária, que evidenciou certa ruptura na tradicional estrutura de propriedade acionária exclusivamente concentrada, até então predominante nas companhias brasileiras. Diante desse cenário contrastante, de mudanças no perfil do poder de controle sobre as companhias brasileiras, o presente trabalho apresentará em seu capítulo terceiro, após breve análise das estruturas de capital identificadas em diferentes economias e de retrospectiva sobre a propriedade acionária das companhias brasileiras (a serem apresentadas em seu segundo capítulo), extensa pesquisa empírica realizada com o propósito de identificar a atual estrutura de propriedade acionária predominante entre as companhias brasileiras listadas no segmento especial do Novo Mercado da BMF&BOVESPA (Novo Mercado), e com o objetivo de averiguar a existência do chamado controle societário minoritário entre tais companhias, conforme detalhado nos apêndices desta dissertação. Referida pesquisa empírica representa, ainda, rico processamento da base de dados e informações divulgadas à Comissão de Valores Mobiliários (CVM) pelas companhias listadas no Novo Mercado, e serve de base para a avaliação da necessidade de eventuais mudanças nos conceitos adotados pelo Direito Societário pátrio, tendo em vista entendimento divergente identificado na doutrina e em julgados da CVM no âmbito da possibilidade de existência de um controle societário exercido por acionista ou grupo de acionistas não detentores da maioria do capital social votante, conforme detalhado no quarto capítulo deste estudo. Por fim, serão apresentadas, no quinto e último capítulo, as considerações finais à análise proposta, com destaque para as principais conclusões obtidas na elaboração dos capítulos terceiro e quarto descritos acima, dentre elas a existência do controle societário interno não majoritário (controle minoritário) entre companhias listadas no Novo Mercado, bem como os reflexos dessa constatação no âmbito da prática do Direito Societário. / Among the current challenges of the Brazilian Corporate Law, the structure of the capital ownership of the corporations and the identification of those who exercises control over it remains an important aspect to be taken into consideration when analyzing the main aspects of the Brazilian capital market. The heat up of the transactions carried out through the capital market, and the consolidation of the special corporate governance segments in Brazil resulted in the so called phenomenon of the dispersed ownership, which revealed a rupture from the traditional structure of extremely concentrated ownership, that was prevailing until now among the Brazilian corporations. Given such contrasting scenario of changes in the profile of corporate power over Brazilian corporations, these thesis, after describing, over its first two chapters, the structures of capital ownership existent in different economies and providing a retrospective on the capital ownership of Brazilian corporations, presents, in its third chapter, an extensive empirical research performed with the purposes of identifying the current structure of capital ownership prevailing among the Brazilian companies listed in the Novo Mercado, special segment of the Brazilian Exchange BMF&BOVESPA (the New Market), as well as ascertaining the existence of minority corporate control among such companies, as detailed in the appendixes hereto. The referred empirical research presents, furthermore, detailed data processing in connection with the information disclosed by such companies to the Brazilian Stock Exchange Commission, the Comissão de Valores Mobiliários (CVM), and is also used as basis for reviewing the need of eventual changes in the concepts embodied by the Brazilian Corporate Law, in view of the divergent understanding identified in the Brazilian doctrine and judgments issued by the CVM in connection with the existence of a corporate control exercised by a shareholder or group of shareholders owner of shareholding not representative of the majority of the voting capital stock, as detailed in the fourth chapter of these thesis. Finally, the fifth and last chapter of these study presents the final considerations in connection with the review proposed hereto, highlighting the main conclusions obtained through the elaboration of the third and fourth chapters described above, among them the existence of a not majority internal control (minority control) in companies listed in the New Market, as well as the effects of such conclusion in the light of the practice of corporate law.
19

Ovládání invalidního vozíku pomocí klasifikace EEG signálu / Wheelchair control using EEG signal classification

Malý, Lukáš January 2015 (has links)
Tato diplomová práce představuje koncept elektrického invalidního vozíku ovládaného lidskou myslí. Tento koncept je určen pro osoby, které elektrický invalidní vozík nemohou ovládat klasickými způsoby, jakým je například joystick. V práci jsou popsány čtyři hlavní komponenty konceptu: elektroencefalograf, brain-computer interface (rozhraní mozek-počítač), systém sdílené kontroly a samotný elektrický invalidní vozík. V textu je představena použitá metodologie a výsledky provedených experimentů. V závěru jsou nastíněna doporučení pro budoucí vývoj.
20

Conception des principes de coopération conducteur-véhicule pour les systèmes de conduite automatisée / Designing driver-vehicle cooperation principles for automated driving systems

Guo, Chunshi 29 May 2017 (has links)
Face à l’évolution rapide des technologies nécessaires à l’automatisation de la conduite au cours de ces dernières années, les grands constructeurs automobiles promettent la commercialisation de véhicules autonomes à l’horizon 2020. Cependant, la définition des interactions entre les systèmes de conduite automatisée et le conducteur au cours de la tâche de conduite reste une question ouverte. L'objectif de cette thèse est de concevoir, développer et évaluer des principes de coopération entre le conducteur et les systèmes de conduite automatisée. Compte tenu de la complexité d'un tel Système Homme-Machine, la thèse propose, en premier lieu une architecture de contrôle coopératif hiérarchique et deux principes de coopération généraux sur deux niveaux dans l’architecture qui serviront ensuite de base commune pour la conception des systèmes coopératifs développés pour les cas d’usages définis. Afin d’assurer une coopération efficace avec le conducteur dans un environnement de conduite dynamique, le véhicule autonome a besoin de comprendre la situation et de partager sa compréhension de la situation avec le conducteur. Pour cela, cette thèse propose un formalisme de représentation de la scène de conduite basé sur le repère de Frenet. Ensuite, une méthode de prédiction de trajectoire est également proposée. Sur la base de la détection de manœuvre et de l'estimation du jerk, cette méthode permet d’améliorer la précision de la trajectoire prédite comparée à celle déterminée par la méthode basée sur une hypothèse d'accélération constante. Dans la partie d’études de cas, deux principes de coopération sont mis en œuvre dans deux cas d’usage. Dans le premier cas de la gestion d’insertion sur autoroute, un système de contrôle longitudinal coopératif est conçu. Il comporte une fonction de planification de manœuvre et de génération de trajectoire basée sur la commande prédictive. En fonction du principe de coopération, ce système peut à la fois gérer automatiquement l’insertion d’un véhicule et donner la possibilité au conducteur de changer la décision du système. Dans le second cas d'usage qui concerne le contrôle de trajectoire et le changement de voie sur autoroute, le problème de partage du contrôle est formulé comme un problème d’optimisation sous contraintes qui est résolu en ligne en utilisant l’approche de la commande prédictive (MPC). Cette approche assure le transfert continu de l’autorité du contrôle entre le système et le conducteur en adaptant les pondérations dans la fonction de coût et en mettant en œuvre des contraintes dynamiques en ligne dans le modèle prédictif, tout en informant le conducteur des dangers potentiels grâce au retour haptique sur le volant. Les deux systèmes sont évalués à l’aide de tests utilisateur sur simulateur de conduite. En fonction des résultats des tests, cette thèse discute la question des facteurs humains et la perception de l'utilisateur sur les principes de coopération. / Given rapid advancement of automated driving (AD) technologies in recent years, major car makers promise the commercialization of AD vehicles within one decade from now. However, how the automation should interact with human drivers remains an open question. The objective of this thesis is to design, develop and evaluate interaction principles for AD systems that can cooperate with a human driver. Considering the complexity of such a human-machine system, this thesis begins with proposing two general cooperation principles and a hierarchical cooperative control architecture to lay a common basis for interaction and system design in the defined use cases. Since the proposed principles address a dynamic driving environment involving manually driven vehicles, the AD vehicle needs to understand it and to share its situational awareness with the driver for efficient cooperation. This thesis first proposes a representation formalism of the driving scene in the Frenet frame to facilitate the creation of the spatial awareness of the AD system. An adaptive vehicle longitudinal trajectory prediction method is also presented. Based on maneuver detection and jerk estimation, this method yields better prediction accuracy than the method based on constant acceleration assumption. As case studies, this thesis implements two cooperation principles for two use cases respectively. In the first use case of highway merging management, this thesis proposes a cooperative longitudinal control framework featuring an ad-hoc maneuver planning function and a model predictive control (MPC) based trajectory generation for transient maneuvers. This framework can automatically handle a merging vehicle, and at the mean time it offers the driver a possibility to change the intention of the system. In another use case concerning highway lane positioning and lane changing, a shared steering control problem is formulated in MPC framework. By adapting the weight on the stage cost and implementing dynamic constraints online, the MPC ensures seamless control transfer between the system and the driver while conveying potential hazards through haptic feedback. Both of the designed systems are evaluated through user tests on driving simulator. Finally, human factors issue and user’s perception on these new interaction paradigms are discussed.

Page generated in 0.0458 seconds