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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.
101

Simulation of Biological Tissue using Mass-Spring-Damper Models / Simulering av biologisk vävnad med hjälp av mass-spring-damper-modeller

Eriksson, Emil January 2013 (has links)
The goal of this project was to evaluate the viability of a mass-spring-damper based model for modeling of biological tissue. A method for automatically generating such a model from data taken from 3D medical imaging equipment including both the generation of point masses and an algorithm for generating the spring-damper links between these points is presented. Furthermore, an implementation of a simulation of this model running in real-time by utilizing the parallel computational power of modern GPU hardware through OpenCL is described. This implementation uses the fourth order Runge-Kutta method to improve stability over similar implementations. The difficulty of maintaining stability while still providing rigidness to the simulated tissue is thoroughly discussed. Several observations on the influence of the structure of the model on the consistency of the simulated tissue are also presented. This implementation also includes two manipulation tools, a move tool and a cut tool for interaction with the simulation. From the results, it is clear that the mass-springdamper model is a viable model that is possible to simulate in real-time on modern but commoditized hardware. With further development, this can be of great benefit to areas such as medical visualization and surgical simulation. / Målet med detta projekt var att utvärdera huruvida en modell baserad på massa-fjäderdämpare är meningsfull för att modellera biologisk vävnad. En metod för att automatiskt generera en sådan modell utifrån data tagen från medicinsk 3D-skanningsutrustning presenteras. Denna metod inkluderar både generering av punktmassor samt en algoritm för generering av länkar mellan dessa. Vidare beskrivs en implementation av en simulering av denna modell som körs i realtid genom att utnyttja den parallella beräkningskraften hos modern GPU-hårdvara via OpenCL. Denna implementation använder sig av fjärde ordningens Runge-Kutta-metod för förbättrad stabilitet jämfört med liknande implementationer. Svårigheten att bibehålla stabiliteten samtidigt som den simulerade vävnaden ges tillräcklig styvhet diskuteras genomgående. Flera observationer om modellstrukturens inverkan på den simulerade vävnadens konsistens presenteras också. Denna implementation inkluderar två manipuleringsverktyg, ett flytta-verktyg och ett skärverktyg för att interagera med simuleringen. Resultaten visar tydligt att en modell baserad på massa-fjäder-dämpare är en rimlig modell som är möjlig att simulera i realtid på modern men lättillgänglig hårdvara. Med vidareutveckling kan detta bli betydelsefullt för områden så som medicinsk bildvetenskap och kirurgisk simulering.
102

Etudes des mécanismes sous-jacents aux phénomènes collectifs chez un primate non humain, cebus capucinus: de l'expérimentation à la modélisation / Decision-making processes involved in collective phenomena in semi-free ranging non human primates, cebus capucinus: from experimental approach to mathematical modelling

Meunier, Hélène 26 March 2007 (has links)
Ce doctorat trouve son origine dans la compréhension des prises de décision et des comportements collectifs des animaux. Comment ces derniers parviennent-ils à effectuer des choix collectivement ?Comment les membres d’un groupe procèdent-ils pour synchroniser leurs comportements spatialement et temporellement ?Mon principal objectif a été de dégager, lors des déplacements collectifs et du fur rubbing chez le capucin moine, les évènements décisionnels dépendants de processus anonymes de ceux dépendants de processus liés à l’identité des individus et à leur réseau de relations sociales au sein du groupe. Dans les prises de décision collective relatives aux déplacements, les membres du groupe sont influencés dans leurs choix par leur identité sociale mais aussi par des mécanismes anonymes, de type mimétique. Le fur rubbing est également un comportement collectif dont les mécanismes sous-jacents incluent une dépendance interindividuelle de type mimétique. Des mécanismes similaires mettant en jeu des interactions entre individus basées sur des règles comportementales simples se retrouvent dans chacun des phénomènes collectifs étudiés. Ces résultats sont les premiers à démontrer l’émergence de prises de décision collective à partir de telles interactions anonymes dans un groupe de primates non humains. Ils permettent de faire le lien entre choix individuels et comportement collectif et de mieux concevoir comment un groupe de primates peut se coordonner, maintenir sa cohésion spatiale et synchroniser ses activités./How do animals reach collective consensus? How do group members spatially and temporally synchronise their behaviour? My main purpose was to demonstrate the respective roles of anonymous processes (contagion, mimetism) and individual-dependent processes (hierarchical rank, age, sex, kin, social relationships) in collective decision-making. During decision-making relating to collective movements, group members’ decisions depend on their social identity (individual-dependent mechanism) as well as anonymous processes. Fur rubbing is also a collective behaviour involving interindividual dependence with mimetic underlying mechanisms. We found similar mechanisms, involving interindividual interactions according to simple behavioural rules, in both collective phenomenon studied. These results are the first to demonstrate the emergence of collective decision-making based on anonymous interactions in a group of non human primates. They help to understand the link between individual choices and collective behaviour and to appreciate how a social group of primates maintain its spatial cohesion and synchronize its activities. / Doctorat en sciences, Spécialisation biologie animale / info:eu-repo/semantics/nonPublished
103

Implementace statistických kompresních metod / Implementation of Statistical Compression Methods

Štys, Jiří January 2013 (has links)
This thesis describes Burrow-Wheeler compression algorithm. It focuses on each part of Burrow-Wheeler algorithm, most of all on and entropic coders. In section are described methods like move to front, inverse frequences, interval coding, etc. Among the described entropy coders are Huffman, arithmetic and Rice-Golomg coders. In conclusion there is testing of described methods of global structure transformation and entropic coders. Best combinations are compared with the most common compress algorithm.
104

Navigation Control & Path Planning for Autonomous Mobile Robots / Navigation Control and Path Planning for Autonomous Mobile Robots

Pütz, Sebastian Clemens Benedikt 11 February 2022 (has links)
Mobile robots need to move in the real world for the majority of tasks. Their control is often intertwined with the tasks they have to solve. Unforeseen events must have an adequate and prompt reaction, in order to solve the corresponding task satisfactorily. A robust system must be able to respond to a variety of events with specific solutions and strategies to keep the system running. Robot navigation control systems are essential for this. In this thesis we present a robot navigation control system that fulfills these requirements: Move Base Flex. Furthermore, the map representation used to model the environment is essential for path planning. Depending on the representation of the map, path planners can solve problems like simple 2D indoor navigation, but also complex rough terrain outdoor navigation with multiple levels and varying slopes, if the corresponding representation can model them accurately. With Move Base Flex, we present a middle layer navigation framework for navigation control, that is map independent at its core. Based on this, we present the Mesh Navigation Stack to master path planning in complex outdoor environments using a developed mesh map to model surfaces in 3D. Finally, to solve path planning in complex outdoor environments, we have developed and integrated the Continuous Vector Field Planner with the aforementioned solutions and evaluated it on five challenging and complex outdoor datasets in simulation and in the real-world. Beyond that, the corresponding developed software packages are open source available and have been released to easily reproduce the provided scientific results.
105

Le droit à la mobilité de la main-d’œuvre professionnelle au Canada : au-delà des grands principes, une protection individuelle limitée

St-Amour Blais, Josette 12 1900 (has links)
La liberté de circulation et la liberté d’établissement sont reconnues comme fondamentales et intrinsèquement liées au principe de dignité humaine. Pourtant, au nom de la souveraineté nationale, les États imposent des limites à la mobilité humaine. La mobilité de la main-d’œuvre est nécessaire au fonctionnement de l’économie et peut répondre en partie aux enjeux de pénurie de travailleurs. Notre thèse propose une recherche en droit positif visant à circonscrire la portée du droit à la mobilité en droit canadien. De fait, l’article 6 (2) de la Charte canadienne des droits et libertés reconnaît aux citoyens et résidents permanents au Canada la liberté de circulation et le droit de gagner leur vie. Toutefois, l’alinéa 6 (3) a) de la Charte contient une restriction à ces droits. Les provinces demeurent autorisées à légiférer pour limiter la mobilité, tant qu’elles n’imposent pas de discrimination basée sur la province de résidence. Nous soutenons que dans l’état actuel de la jurisprudence canadienne, le droit à la mobilité n’est pas considéré comme une liberté fondamentale. Pour leur part, les accords de commerce entre les membres de la confédération, sur le plan national, et les accords bilatéraux, régionaux et multilatéraux entre le Canada et ses partenaires contiennent des dispositions encadrant la mobilité de la main-d’œuvre. Lors des négociations constitutionnelles qui ont précédé et suivi le rapatriement de la constitution canadienne en 1982, le développement de l’union économique au pays et l’inclusion du droit à la mobilité ont été au cœur des débats. Or l’analyse des décisions de la Cour suprême du Canada portant sur l’article 6 (2) démontre pourtant que c’est uniquement la non-discrimination sur la base de la province de résidence qui est garantie par la Charte. Les instruments internationaux relatifs aux droits de la personne établissent le droit à la mobilité comme un droit fondamental, mais la recension des différents accords de libre-échange permet de conclure que la mobilité de la main-d’œuvre est favorisée essentiellement pour répondre aux besoins économiques. Le droit à la mobilité ne devrait pas uniquement répondre aux besoins des aléas économiques. Dans cette perspective, la reconnaissance des compétences et des qualifications s’avère impérative pour que le droit à la mobilité soit réellement effectif. / The rights to move, the right to take up residence, and the right to gain a livelihood are recognized as fundamental and are intrinsically linked to the principle of human dignity. Yet, in the name of national sovereignty, states impose limits on human mobility. Labor mobility is a pillar of world economy and can address many aspects of workforce shortages. Our research examines current constraints to, and the scope of, the right to mobility under Canadian law. Indeed, section 6 (2) of the Canadian Charter of Rights and Freedoms recognizes the right to move and the right to gain a livelihood for citizens and permanent residents of Canada. However, section 6 (3) a) of the Charter contains a limitation on these rights. Provinces remain authorized to limit mobility, as long as they do not discriminate on the basis of province of residence. We argue that, as Canadian jurisprudence currently stands, mobility rights are not considered a fundamental freedom. On the other hand, trade agreements between members of confederation, at the national level, and bilateral, regional, and multilateral agreements between Canada and its international partners, contain provisions regulating labor mobility. During the constitutional negotiations that preceded and followed the repatriation of the Constitution Act, 1982, the development of the economic union in Canada and the inclusion of mobility rights were at the heart of the debate. However, an analysis of the Supreme Court of Canada's decisions on section 6(2) shows that the Canadian Charter guarantees non-discrimination on the basis of province of residence. International human rights instruments establish the mobility rights as a fundamental right, but a review of various free trade agreements suggests that labor mobility is promoted primarily to meet economic needs. Mobility rights should not uniquely answer economic requirements. Against this background, the recognition of skills and qualifications is imperative to ensure that mobility rights are effective.
106

Teleworks effect on job-related relocation decisions : A study of the Swedish workforce

Ramstedt, Ellinor January 2023 (has links)
With teleworking becoming an increasingly normalized work arrangement after the Covid-19 pandemic, it opens up possibilities for workers to be located elsewhere than their workplace. This indicates that work-related relocation may not be a necessity anymore for parts of the workforce, because they can choose to work remotely instead of relocating. The overall purpose of the thesis has been to investigate whether the normalization of telework as a part of the employee value proposition’s benefits will make people in the workforce less likely to relocate for work. The employee value proposition theory was used to understand the current role telework has as a part of the benefit component, and how telework may affect the employees' likelihood to relocate for work. Two research questions were used to answer the overall purpose:  Has telework resulted in the benefit component having a greater influence than other components for the workforce? Has telework offered as a benefit made people in the workforce less likely to relocate for work? The research purpose for the study was exploratory and the research approach was a deductive, qualitative study approach. Semi-structured interviews were used to collect the data and the sampling were selected by both the purposive and snowball sampling method. The sample for the interviews were employees who have a job where it is possible to do teleworking and were between 25-35 years old. After the interviews were conducted, the data was analyzed by using thematic analysis. The finding of the study indicates that the influence of the benefit component did not change compared to previous research and still had a mid-level of importance. It is not likely that telework has made the benefit component to have an overall greater influence compared to other components, but there were components such as affiliation that were very influential when making relocation decisions. It was also found that family members, especially partners and children, were a big influence on relocation decisions. The participants were more likely to consider teleworking instead of relocating when they had partners and children. Several of them could not see themselves only doing teleworking long-term though, because the connection with the colleagues and team at their workplace were also important. The findings of the study indicate that human connection and relationships have become increasingly important for the employees, and this affects both their teleworking and relocation decisions.
107

Příčiny války v Iráku: Proč se administrativa USA rozhodla zahájit válku v Iráku v roce 2003 / The Causes of Iraqi War: Why the US Administration decided to invade Iraq in 2003

Bartková Sodomová, Renáta January 2009 (has links)
The thesis: "The Causes of Iraqi War: Why the US Administration decided to invade Iraq in 2003" focuses on explanation why the administration of the USA made that step. The specification of the roots of war is based on five causes and seventeen subcauses according to the essay of Stephen Van Evera and other scholars, and the paper trough the methodology of text's analyzes investigates behavior, decision-making process and motivations of the US administration (the level of units) and some steps of the US president G. W. Bush (individual level) in the process leading to the war in Iraq. Concerning the causes of war, the paper introduces different concepts of the offense-defense balance and analyzes whether the balance was disrupted. Secondly, it examines the role of cumulative resources in Iraq like oil, territory and state structures and it shows how they influenced the decision. Third, it searches for the linkage among an emergence of a new threat and responses to it which mouthed to the acceptance of the concept of the first move advantage. Fourth, the thesis accounts for the roots of misperception, where they originate and how they operated in perception of the US administration of the Iraqi threat. Finally, the investigation of the last root of conflict explains why and how windows of...

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