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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.
11

Test et évaluation de la robustesse de la couche fonctionnelle d'un robot autonome / Test and Evaluation of the Robustness of the Functional Layer of an Autonomous Robot

Chu, Hoang-Nam 01 September 2011 (has links)
La mise en oeuvre de systèmes autonomes nécessite le développement et l'utilisation d'architectures logicielles multi-couches qui soient adaptées. Typiquement, une couche fonctionnelle renferme des modules en charge de commander les éléments matériels du système et de fournir des services élémentaires. Pour être robuste, la couche fonctionnelle doit être dotée de mécanismes de protection vis-à-vis de requêtes erronées ou inopportunes issues de la couche supérieure. Nous présentons une méthodologie pour tester la robustesse de ces mécanismes. Nous définissons un cadre général pour évaluer la robustesse d'une couche fonctionnelle par la caractérisation de son comportement vis-à-vis de requêtes inopportunes. Nous proposons également un environnement de validation basé sur l'injection de fautes dans le logiciel de commande d'un robot simulé. Un grand nombre de cas de tests est généré automatiquement par la mutation d'une séquence de requêtes valides. Les statistiques descriptives des comportements en présence de requêtes inopportunes sont analysées afin d'évaluer la robustesse du système sous test. / The implementation of autonomous systems requires the development and the using of multi-layer software architecture. Typically, a functional layer contains several modules that control the material of the system and provide elementary services. To be robust, the functional layer must be implemented with protection mechanisms with respect to erroneous or inopportune requests sent from the superior layer. We present a methodology for robustness testing these mechanisms. We define a general framework to evaluate the robustness of a functional layer by characterizing its behavior with respect to inappropriate requests. We also propose an validation environment based on fault injection in the control software of a simulated robot. A great number of test cases is generated automatically by the mutation of a sequence of valid requests. The descriptive statistics of the behaviors in the presence of inappropriate requests are analyzed in order to evaluate the robustness of the system under test.
12

Un calcul de réécriture de graphes : applications à la biologie et aux systèmes autonomes / A rewriting calculus for graphs : applications to biology and autonomous systems

Andrei, Oana-Maria 05 November 2008 (has links)
L'objectif de cette thèse est d'explorer des descriptions formelles pour la structure et le fonctionnement des systèmes biologiques, ainsi que des outils formels pour raisonner au sujet de leur comportement. Cette thèse s'inscrit dans les travaux étudiant les modèles informatiques sûrs où les calculs sont exprimés par l'intermédiaire de la réécriture, et où nous pouvons compter sur la vérification formelle pour exprimer et valider les propriétés des modèles. Dans cette thèse nous développons un calcul de réécriture d'ordre supérieur pour décrire des molécules, des règles de réaction, et la génération des réseaux biochimiques. Le calcul est basé sur la métaphore chimique en décrivant les calculs en termes de solutions chimiques dans lesquelles les molécules représentant des données agissent l'une sur l'autre librement selon des règles de réaction. Ainsi nous avons obtenu un Calcul Biochimique Abstrait étendant le modèle chimique d'ordre supérieur en considérant des molécules structurées. Le calcul est équipé d'une spécification naturelle de la concurrence et des mécanismes de contrôle grâce à l'expression des stratégies de réécriture sous forme de molécules. La description des complexes moléculaires ou des réactifs chimiques appartient à une classe spécifique de graphes. Nous définissons la structure des graphes avec ports et nous montrons que les principes du calcul biochimique instanciés pour les graphes avec ports sont assez expressifs pour modéliser des systèmes autonomes et des réseaux biochimiques. En plus, les techniques de la réécriture stratégique ouvrent la voie au raisonnement basé sur les calculs et à la vérification des propriétés des systèmes modélisés / The objective of this thesis is to explore formal descriptions for the structure and functioning of biological systems, as well as formal tools for reasoning about their behavior. This work takes place in the overall prospective to study safe computational models where computations are expressed via rewriting, and where we can rely on formal verification to express and validate suitable properties. In this thesis we develop a higher-order calculus rewriting for describing molecules, reaction patterns, and biochemical network generation. The calculus is based on the chemical metaphor by describing the computations in terms of chemical solutions in which molecules representing data freely interact according to reaction rules. This way we obtained an Abstract Biochemical Calculus as an extension of the higher-order chemical model by considering structured molecules. The calculus is provided with a natural specification of concurrency and of controlling mechanisms by expressing rewrite strategies as molecules. The description of molecular complexes or chemical reactants belong to specific classes of graphs. We define the structure of port graphs and we show how the principles of the biochemical calculus instantiated for port graphs are expressive enough for modeling autonomous systems and biochemical networks. In addition, strategic rewriting techniques open the way to reason about the computations and to verify properties of the modeled systems
13

Trust in human-computer relationships : Do cross country skiers have trust towards a physical intelligent tutoring system as an accurate feedback on performance?

Thorsén, Karolina, Lindström, Anna January 2018 (has links)
Trust is one of the attitudes that can affect the intentions and the behavior of a human using a system. Misusing a system can have safety- as well as economic consequences, this is why it is important that a user develops calibrated trust towards a system. In this report, the research question is: how much trust cross country skiers have towards a physical intelligent tutoring system (PITS)? Six biological males (age 24 to 50) roller skied on a mechanical treadmill and received feedback from the PITS on a TV-screen. Experience of using the PITS was evaluated with an instrument in a semi-structured interview. The instrument measured the participants overall perceived trust (OPT) for the system, and the participants were asked to further their thoughts about the statements. The data was transcribed, coded, and categorized in a thematic analysis. The result showed that a majority of the participants had low OPT for the PITS, and the thematic analysis showed that the minority with higher levels of OPT focused on the choice of an elite skier as the reference skier. One of the problems with the instrument was that it was developed for evaluation in long term usage, and not first time usage as in this study. The result of this report can be used for further development of the PITS and a reminder on why trust needs to be considered when creating user experiences.
14

âUma Proposta de Projeto Para Inversor MultinÃvel em Cascata AssimÃtrico com 63 NÃveis na TensÃo de SaÃda e OperaÃÃo em Baixa FrequÃnciaâ / "Design Proposition For a 63 Levels Output Voltage Asymmetric Multilevel Cascaded Inverter at low Frequency Operation"

Samuel Jo de Mesquita 11 February 2011 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / "Este trabalho apresenta um estudo dos inversores multinÃveis em cascata usando cÃlulas H-bridge na configuraÃÃo assimÃtrica usando transformador de mÃltiplos secundÃrios. Ele demonstra equaÃÃes para o cÃlculo da freqÃÃncia das cÃlulas para o inversor operando com as configuraÃÃes binÃria e ternÃria, bem como o projeto completo do transformador toroidal com nÃcleo laminado. Este trabalho define a melhor freqÃÃncia de operaÃÃo do transformador que possibilita reduÃÃo no tamanho se comparado a operaÃÃo em 60 Hz. Ele tambÃm aborda uma metodologia para o cÃlculo das perdas nas cÃlulas do inversor as quais sÃo Ãteis para o cÃlculo tÃrmico do inversor." / This dissertation proposes a design of a cascaded multilevel inverter using H-bridge cells in asymmetric configuration and a multiple secondary transformer. Equations for determining the frequency operation of each cell with binary and ternary configurations, as well as the complete design of toroidal transformer with laminated core. This work proposes also the optimal operating frequency of the transformer that enables reduction in core size, when compared to 60 Hz operation. It is also discussed a methodology for calculate the losses in the cells of the inverter, which are useful to determine the thermal behavior of the inverter.
15

[en] JAT4BDI: A NEW APPROACH TO TESTING DELIBERATIVE AGENTS / [pt] JAT4BDI: UMA NOVA ABORDAGEM PARA TESTES DE AGENTES DELIBERATIVOS

06 December 2021 (has links)
[pt] O crescimento e a popularidade da web impulsionaram o desenvolvimento de softwares baseados em rede. O uso de sistemas multiagentes (SMAs) nesse contexto é considerado uma abordagem promissora em vem sendo aplicada em diferentes áreas tais como: segurança, missões ou cenários críticos de negócios, monitoramento avançado de ambientes e pessoas, etc., o que significa que analisar as escolhas que este tipo de software pode fazer torna-se crucial. Contudo, as metodologias propostas até o momento pela Engenharia de Software Orientada a Agentes (AOSE) concentraram seus esforços principalmente no desenvolvimento de abordagens disciplinadas para analisar, projetar e implementar um SMA e pouca atenção tem sido dada a forma como tais sistemas podem ser testados. Além disso, no que se refere a testes envolvendo agentes de software, algumas questões relacionadas à observabilidade e a controlabilidade dificultam a tarefa de verificação do comportamento, tais como: (i) a autonomia do agente em seu processo deliberativo; (ii) o fato das crenças e objetivos do agente estarem embutidos no próprio agente, dificultam a observação e controle do comportamento e; (iii) problemas associados à cobertura dos testes. Neste trabalho é apresentada uma nova abordagem para testes unitários de agentes BDI escritos em BDI4JADE baseadas na combinação e adaptação das ideias suportadas pelo JAT Framework, um framework de testes para agentes escritos em JADE e no modelo de faltas proposto por Zhang. / [en] The growth and popularity of the Web has fueled the development of software-based network. The use of multi-agent systems (MAS) in this context is considered a promising approach has been applied in different areas such as security, or mission critical business scenarios, enhanced monitoring of environments and people, etc., which means analyzing the choices that this type of software can become crucial. However, the methodologies proposed so far by the Software Engineering Oriented Agents (AOSE) focused their efforts mainly on developing disciplined approach to analyze, design and implement an SMA and little attention has been given to how such systems can be tested. Furthermore, with regard to tests involving software agents, some issues related to the controllability and observability difficult the task of checking the behavior, such as: (i) the duration of the agent in its decision-making process; (ii) the fact of the agent s beliefs and goals are embedded in the agent itself, hampering the observation and control of behavior; (iii) problems associated with test coverage. In this research a novel approach for unit testing of agents written in BDI4JADE BDI based on the combination and arrangement of ideas supported by JAT Framework, a framework for testing agents written in JADE and fault model proposed by Zhang is displayed.
16

Processus Décisionnels de Markov pour l'autonomie ajustable et l'interaction hétérogène entre engins autonomes et pilotés / Markov Decision Processes for adjustable autonomy and heterogeneous interaction between autonomous and piloted robots

Lelerre, Mathieu 17 May 2018 (has links)
Les robots vont être de plus en plus utilisés dans les domaines civils, comme dans le domaine militaire. Ces robots, opérant en flottes, peuvent accompagner des soldats au combat, ou accomplir une mission en étant supervisés par un poste de contrôle. Du fait des exigences d'une opération militaire, il est difficile de laisser les robots décider de leurs actions sans accord d'un opérateur ou surveillance, en fonction de la situation. Dans cette thèse, nous nous attardons sur deux problématiques:D'une part, nous cherchons à exploiter l'autonomie ajustable de sorte à ce qu'un robot puisse accomplir sa mission de la manière la plus efficace possible, tout en respectant des restrictions assignées par un opérateur sur son niveau d'autonomie. Pour cela, celui-ci est en mesure de définir pour un ensemble d'états et d'actions donné un niveau de restriction. Ce niveau peut par exemple imposer au robot la télé-opération pour accéder à une zone à risque.D'autre part, comme nous envisageons la possibilité que plusieurs robots soient déployés en même temps, ces robots doivent se coordonner pour accomplir leurs objectifs. Seulement, comme les opérateurs peuvent prendre le contrôle de certains d'entre eux, la question de la coordination se pose. En effet, l'opérateur ayant ses propres préférences, perception de l'environnement, connaissances et étant sujet aux stress, hésitations, il est difficile de prévoir les actions que celui-ci va effectuer, et donc de s'y coordonner. Nous proposerons dans cette thèse une approche visant à estimer la politique exécutée par un robot télé-opéré à partir d'apprentissage basé sur les actions observés de ce robot.La notion de planification est très présente dans ces travaux. Ceux-ci se baseront sur des modèles de planifications comme les Processus Décisionnels de Markov. / Robots will be more and more used in both civil and military fields. These robots, operating in fleet, can accompany soldiers in fight, or accomplish a mission while being supervised by a control center. Considering the requirement of a military operation, it is complicated to let robots decide their action without an operator agreement or watch, in function of the situation.In this thesis, we focus on two problematics:First, we try to exploit adjustable autonomy to make a robot accomplishes is mission as efficiency as possible, while he respects restrictions, assigned by an operator, on his autonomy level. For this, it is able to define for given sets of states and actions a restriction level. This restriction can force, for example, the need of being tele-operated to access a dangerous zone.Secondly, we consider that several robots can be deployed at the same time. These robots have to coordinate to accomplish their objectives. However, since operators can take the control of some robots, the coordination is harder. In fact, the operator has preferences, perception, hesitation, stress that are not modeled by the agent. It is then hard to estimate his next actions, so to coordinate with him. We propose in this thesis an approach to estimate the policy executed by a tele-operated robot from learning methods, based on observed actions from this robot.The notion of planning his important in these works. These are based on planning models, such as Markov Decision Processes.
17

Autonomous Compaction Roller : Temporarily convert a non autonomous compaction machine to become autonomous during endurance testing

Tuma Fischer, Sebastian, Sundblad, Jojje January 2018 (has links)
How can a non-autonomous compaction roller be converted to become temporarily autonomous while it performs a 500hours endurance test? Particularlysince the compaction rollers in question is not built to be autonomous and shall not be autonomous after the endurance test is completed. The autonomous system shall also be adaptable to all compaction rollers which Dynapac is developing and shall be moved to another machine when the endurance test is completed. In this thesis a concept is engineered of how the whole autonomous system will work and a prototype is fabricated of how to convert the current manual mechanical steering to be performed by a computer. The steering prototype has been tested on a Dynapac CC4200 double drumasphalt compaction roller and worked as intended. To develop this, anextensive risk analysis is also established andwith it a requirements list of what's needed to be fulfilled when performing autonomous testing of a compaction roller. The work has been done using the method “design thinking” which is a collection of multiple methods to create new concepts and ideas. The final concept resulted in a navigation system which uses GNSS for path planning and limitation of the operation area. It also uses radar to detect foreign objects in its path to prevent a collision. Multiple systems arealso proposed to be used for malfunction detection of the roller, which is a major part of a human operator’sjob when testing out new machines. The test track for the machine was undefined and also hadto be engineeredas part of the concept. It resultedin closing the area of operation with a mesh fence to prevent access to the area from unauthorised personnel and geo-fence to prevent the machine from escaping. Access to the area is only granted to authorized personnel and only when the autonomous rolleris shut off. Due to the machines in question isn’t fully developed, theycan’t be trusted enough to have people inside the area of operation asthe autonomous machineis operating. / Hur kanen icke-autonom vägvältomvandlas tillatt bli tillfälligt autonom medan den utför ett 500timmar långttidsprov?Särskilt sedanvägvältenifrågainte ärbyggd för att vara autonom och ska intevara autonom efter attlångtidsprovetär slutfört. Det autonoma systemet skaävenkunna anpassas tillalla vältar som Dynapac utvecklar och ska flyttas till en annan maskin närlångtidsprovetär klart. Idenna avhandling konstrueras ett koncept för hur hela det autonoma systemet kommer att fungera ochenprototyp tillverkaspå hur man konverterar den nuvarande manuella mekaniska styrningen till attstyras av en dator. Styrprototypen testades på en Dynapac CC4200 asfaltsvält med dubbla valsar ochfungerade bra. En omfattande riskanalys utvecklades ochlika såen kravlista över vad som behöveruppnås vid autonom testning av en vägvält. Arbetet har gjorts med hjälp av metoden “designthinking”, vilket är en samling av flera metoder för att skapa nya koncept och idéer. Det slutgiltigakonceptet resulterade i ett navigationssystem som använder GNSS för navigering och begränsning avkörområdet. Den använder också radar för att upptäcka främmande föremål i sin vägvilketförhindrarkollision. Flera system föreslås användasförfunktionsfelsdetektering på välten, vilket är en viktig delav en mänskligoperatörs arbetevid provning av nya maskiner. Maskinen kommer att vara i ett slutetområde som är avskilt med ett nätstängsel.Tillträde till området ges endast till behörig personal ochendast när den autonoma välten är avstängd. På grund avmaskinerna ifråga inte är fullt utvecklade,kan de inte litas på tillräckligt för att ha personer inom körområdet medan det autonoma systemet är idrift.
18

An Evolutionary Analysis of the Internet Autonomous System Network

Stewart, Craig R. 22 June 2010 (has links)
No description available.
19

Support for autonomously driven systems in harsh environments. : Degree project for Master of Science in mechanical engineering with focus on innovation and sustainable product development

Aljafari, Mohammed January 2023 (has links)
Symptoms of harsh environments create pressure on autonomous machines to work wellwith the use of measurement devices. Sensors used within construction equipment vehiclessuffer from being covered with fogs of dirt, oil, water, and dust. Autonomous vehicle’sdependency on fully functional sensors paves roads for research to be made on ways to keepsensor data from being compromised and automation to be improved.In cooperation with Dynapac Compaction Equipment AB, this master’s thesis problemopted for innovative and sustainable product development to tackle the problem. The thesiscomprises of 30 credits. In this thesis, work will be done emphasizing on ways to keepautonomous performance at peak for construction equipment vehicles with low to no capacityfor sophisticated equipment and supply of power and water. For reference, the project targetsasphalt rollers due to their relevance at Dynapac.With the use of innovative product development tools, the problem is to be tackled with anengineering approach revolving around the design thinking process. All progress will beconstituted at Dynapac’s facilities in Karlskrona. Interviews and dialogue with relevantindividuals are to be held to create value based on customer needs which has been of highpriority and is to be iteratively monitored throughout the project. Prototyping will play a partwith large amount of testing to prove concept, including processes of 3dmodeling andmanufacturing of components.With measurement incorrections reaching up to 80 degrees out of a measurement spanwithin the range of 0 to 150 degrees, three concepts have been established, each of which areequipment neutral to benefit construction vehicles which has shown to be valuable within theindustry.A pipe concept which’s purpose is to hide the sensor further and create distance betweensensor lens and measurement surface has been established. The concept is feasible for theconstruction industry, protects the sensor from debris and supports autonomous systems.
20

Facilitating change in the family as an autonomous system : a cybernetic family therapist's perspective

Dagada, Sharon Sarah 06 1900 (has links)
This study aims to show that the adoption of the cybernetic perspective is appropriate in dealing with relationship problems of interacting and communicating individuals since it authenticates the inclusion of the therapist in the therapeutic system, and thus the creation of a reality by all involved, and not just the therapist alone. The constructivist view of the world and the systemic theoretical assumptions are recognized as the required framework for the adopted cybernetic approach. The consideration of the stability/change nature of change is acknowledged as forming the most essential aspects of the change that system require. Thus addressing both stability of what clients need to maintain of themselves, as well as what they want to change is important. The action research methodology used in this research ensured a focus on the actions of the therapist/social worker while facilitating a therapeutic process with a family. Therefore attention could be given to areas requiring change through the planning, acting and reflecting steps throughout the process. / Social Work / M.A. (Social Science (Mental Health))

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