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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.
41

Competitive co-evolution of sensory-motor systems

Buason, Gunnar January 2002 (has links)
A recent trend in evolutionary robotics and artificial life research is to maximize self-organization in the design of robotic systems, in particular using artificial evolutionary techniques, in order to reduce the human designer bias. This dissertation presents experiments in competitive co-evolutionary robotics that integrate and extend previous work on competitive co-evolution of neural robot controllers in a predator-prey scenario with work on the ‘co-evolution’ of robot morphology and control systems. The focus here is on a systematic investigation of tradeoffs and interdependencies between morphological parameters and behavioral strategies through a series of predator-prey experiments in which increasingly many aspects are subject to self-organization through competitive co-evolution. The results show that there is a strong interdependency between morphological parameters and behavioral strategies evolved, and that the competitive co-evolutionary process was able to find a balance between and within these two aspects. It is therefore concluded that competitive co-evolution has great potential as a method for the automatic design of robotic systems.
42

Coordination des tours de parole par le couplage sensorimoteur continu entre utilisateurs et agents / Emergent coordination of speaking turns by the continuous sensory-motor coupling between users and agents

Jégou, Mathieu 05 October 2016 (has links)
Nous présentons dans cette thèse un modèle pour la coordination de la parole dans des interactions dyadiques utilisateur-agent. Selon une approche courante, coordonner la parole reviendrait à éviter les recouvrements de parole et à minimiser les moments de silence entre deux tours, ceci pour rendre plus fluide l’interaction avec l’agent et améliorer l’expérience de l’utilisateur en interaction dialogique avec l’agent. Les interactions humaines montrent néanmoins une coordination plus complexe avec des recouvrements de parole compétitifs ou non compétitifs et des moments de silences longs. Selon notre approche, c’est en permettant cette diversité des situations que nous verrons émerger, entre l’utilisateur et l’agent, une interaction plus fluide et plus crédible, améliorant l’expérience de l’utilisateur avec l’agent. Les échanges de paroles sont néanmoins, par nature, complexes, la coordination se faisant par l’interaction entre locuteur et auditeur plus que par un participant en particulier. Pour capturer cette complexité, nous avons élaboré un modèle mettant l’accent sur une coordination de la parole basée sur un couplage sensorimoteur continu. Sur la base de ce couplage sensorimoteur, le comportement de l’agent n’est pas entièrement contrôlé par ce dernier, mais est émergent de l’interaction entre les participants. Nous montrons la capacité de notre modèle à faire émerger les différentes situations liées à la coordination de la parole humaine à la fois dans une interaction entre deux agents et dans une interaction utilisateur-agent. / In this thesis, we present a model for the coordination of speaking turns in dyadic interactions between users and agents. According to a common view, to coordinate turns means avoiding overlaps and reduces silences between turns. By optimizing turn transitions between users and agents, the user’s experience is expected to be improved. However, observations of human conversations show a more complex coordination of speaking turns between users and agents: awkward silences and overlaps, competitive or not, are common. In order to improve the credibility and the naturalness of the interaction, we must observe the same variability of situations in a user-agent interaction. Nevertheless, coordination of speaking turns is, by nature, complex, the coordination is managed by the interaction between participants more than controlled by one participant alone. To capture this complexity, we elaborated a model emphasizing the continuous sensory-motor coupling existing between the user and the agent. As a result of this sensory-motor coupling, the behavior of the agent is not entirely controlled by the agent but is an emergent property of the interaction between the user and the agent. We show the capacity of our model to make emerge the different situations linked to the coordination of speaking turns in interactions between two agents and between one user and one agent.
43

De l'auto-évaluation aux émotions : approche neuromimétique et bayésienne de l'apprentissage de comportements complexes impliquant des informations multimodales / From self-evaluation to emotions : neuromimetic and bayesian approaches for the learning of complex behavior involving multimodal informations

Jauffret, Adrien 11 July 2014 (has links)
Cette thèse a pour objectif la conception d’une architecture de contrôle bio-inspirée permettant à un robot autonome de naviguer sur de grandes distances. Le modèle développé permet également d’améliorer la compréhension des mécanismes biologiques impliqués. De précédents travaux ont montré qu’un modèle de cellules de lieu, enregistrées chez le rat, permettait à un robot mobile d’apprendre des comportements de navigation robustes, tels qu’une ronde ou un retour au nid, à partir d’associations entre lieu et action. La reconnaissance d’un lieu ne reposait alors que sur des informations visuelles. L’ambiguïté de certaines situations (e.g. un long couloir) ne permettait pas de naviguer dans de grands environnements. L’ajout d’autres modalités constitue une solution efficace pour augmenter la robustesse dans des environnements complexes. Cette solution nous a permis d’identifier les briques minimales nécessaires à la fusion d’informations multimodales, d’abord par le biais d’un conditionnement simple entre 2 modalités sensorielles, puis par la formalisation d’un modèle, plus générique, de prédictions inter-modales. C’est un mécanisme bas niveau qui permet de générer une cohérence perceptive : l’ensemble des modalités sensorielles s’entraident pour ne renvoyer qu’une perception claire et cohérente aux mécanismes décisionnels de plus haut niveau. Les modalités les plus corrélées sont ainsi capables de combler les informations manquantes d’une modalité défaillante (cas pathologique). Ce modèle implique la mise en place d’un système de prédiction et donc une capacité à détecter de la nouveauté dans ses perceptions. Ainsi, le modèle est également capable de détecter une situation inattendue ou anormale et possède donc une capacité d’auto-évaluation : l’évaluation de ses propres perceptions. Nous nous sommes ensuite mis à la recherche des propriétés fondamentales à tout système d'auto-évaluation.La première propriété essentielle a été de constater qu’évaluer un comportement sensorimoteur revient à reconnaître une dynamique entre sensation et action, plutôt que la simple reconnaissance d’une forme sensorielle. La première brique encapsule donc un modèle interne minimaliste des interactions du robot avec son environnement, qui est la base sur laquelle le système fera des prédictions.La seconde propriété essentielle est la capacité à extraire l’information pertinente par le biais de calculs statistiques. Il est nécessaire que le robot apprenne à capturer les invariants statistiques en supprimant l’information incohérente. Nous avons donc montré qu’il était possible d’estimer une densité de probabilité par le biais d’un simple conditionnement. Cet apprentissage permet de réaliser l’équivalent d’une inférence bayésienne. Le système estime la probabilité de reconnaître un comportement à partir de la reconnaissance d’informations statistiques apprises. C’est donc par la mise en cascade de simples conditionnements que le système peut apprendre à estimer les moments statistiques d’une dynamique (moyenne, variance, asymétrie, etc...). La non-reconnaissance de cette dynamique lui permet de détecter qu’une situation est anormale.Mais détecter un comportement inhabituel ne nous renseigne pas pour autant sur son inefficacité. Le système doit également surveiller l’évolution de cette anomalie dans le temps pour pouvoir juger de la pertinence du comportement. Nous montrons comment un contrôleur émotionnel peut faire usage de cette détection de nouveauté pour réguler le comportement et ainsi permettre au robot d’utiliser la stratégie la plus adaptée à la situation rencontrée. Pour finir, nous avons mis en place une procédure de frustration permettant au robot de lancer un appel à l’aide lorsqu’il détecte qu’il se retrouve dans une impasse. Ce réseau de neurones permet au robot d’identifier les situations qu’il ne maîtrise pas dans le but d’affiner son apprentissage, à l’instar de certains processus développementaux. / The goal of this thesis is to build a bio-inspired architecture allowing a robot to autonomouslynavigate over large distances. In a cognitive science point of view, the model also aim at improv-ing the understanding of the underlying biological mechanisms. Previous works showed thata computational model of hippocampal place cells, based on neurobiological studies made onrodent, allows a robot to learn robust navigation behaviors. The robot can learn a round or ahoming behavior from a few associations between places and actions. The learning and recog-nition of a place were only defined by visual information and shows limitations for navigatinglarge environments.Adding other sensorial modalities is an effective solution for improving the robustness of placesrecognition in complex environments. This solution led us to the elementary blocks requiredwhen trying to perform multimodal information merging. Such merging has been done, first,by a simple conditioning between 2 modalities and next improved by a more generic model ofinter-modal prediction. In this model, each modality learns to predict the others in usual situa-tions, in order to be able to detect abnormal situations and to compensate missing informationof the others. Such a low level mechanism allows to keep a coherent perception even if onemodality is wrong. Moreover, the model can detect unexpected situations and thus exhibit someself-assessment capabilities: the assessment of its own perception. Following this model of self-assessment, we focus on the fundamental properties of a system for evaluating its behaviors.The first fundamental property that pops out is the statement that evaluating a behavior is anability to recognize a dynamics between sensations and actions, rather than recognizing a sim-ple sensorial pattern. A first step was thus to take into account the sensation/action couplingand build an internal minimalist model of the interaction between the agent and its environment.Such of model defines the basis on which the system will build predictions and expectations.The second fundamental property of self-assessment is the ability to extract relevant informa-tion by the use of statistical processes to perform predictions. We show how a neural networkcan estimate probability density functions through a simple conditioning rule. This probabilis-tic learning allows to achieve bayesian inferences since the system estimates the probability ofobserving a particular behavior from statistical information it recognizes about this behavior.The robot estimates the different statistical momentums (mean, variance, skewness, etc...) of abehavior dynamics by cascading few simple conditioning. Then, the non-recognition of such adynamics is interpreted as an abnormal behavior.But detecting an abnormal behavior is not sufficient to conclude to its inefficiency. The systemmust also monitor the temporal evolution of such an abnormality to judge the relevance of thebehavior. We show how an emotional meta-controller can use this novelty detection to regu-late behaviors and so select the best appropriate strategy in a given context. Finally, we showhow a simple frustration mechanism allows the robot to call for help when it detects potentialdeadlocks. Such a mechanism highlights situations where a skills improvement is possible, soas some developmental processes.
44

Modulation du réflexe acoustique de sursaut et de l’inhibition par le prépulse : une comparaison entre les jeunes adultes et les âgés

Le Duc, Jolyanne 08 1900 (has links)
Une des théories actuellement prépondérante pour expliquer le déclin cognitif observé chez les personnes âgées est une perte généralisée de la fonction inhibitrice. En revanche, de plus en plus d’études révèlent un maintien et même un gain sur le plan émotionnel chez les âgés. Afin de caractériser l’effet de l’âge sur la fonction inhibitrice et sur les émotions, nous avons utilisé le paradigme bien connu du réflexe acoustique de sursaut et de son inhibition par le prépulse, un phénomène reconnu comme reflétant le filtrage sensorimoteur, soit une mesure pré-attentionnelle d’inhibition. Le réflexe acoustique de sursaut est une réponse du corps tout entier à un bruit fort et inattendu et a été mesuré via la magnitude et la latence du clignement des yeux. La présentation d’un son faible (prépulse) quelques millisecondes avant le bruit de sursaut réduit la réponse de sursaut. Deux groupes de participants (jeunes adultes et âgés) ont visionné des images plaisantes, neutres et déplaisantes issues du International Affective Picture System (IAPS), lesquelles étaient associées à des stimuli auditifs évaluant le réflexe acoustique de sursaut et son inhibition par le prépulse. Les résultats démontrent que le réflexe de sursaut est modulé différemment par les émotions chez les jeunes adultes et les âgés. Plus particulièrement, les adultes âgés ont un plus grand réflexe de sursaut que les jeunes adultes lorsqu’ils visionnent des images plaisantes et neutres. Le processus d’inhibition par le prépulse est également modulé différemment par les émotions chez les âgés et les jeunes adultes: les âgés ont une plus grande inhibition du réflexe de sursaut que les jeunes adultes lorsqu’ils visionnent des images plaisantes et déplaisantes, mais ils ne diffèrent pas des jeunes adultes pour les images neutres. Dans l’ensemble, les résultats obtenus ne sont pas compatibles avec une perte d’inhibition chez les adultes âgés, et supportent plutôt un biais émotionnel positif. / Aging is often characterized by a decline in cognitive abilities and a loss of inhibitory function. At the same time there is promising, yet limited to date, evidence of a better emotion regulation with aging. In order to characterize the effect of age on inhibitory function and emotions, in this study the well-known acoustic startle paradigm and its inhibition by a prepulse, a phenomenon known to engage sensorimotor gating, were used. The acoustic startle reflex, a whole-body reflex in response to a loud and unexpected sound, was measured through eye blink magnitude and latency. The inhibition of this acoustic startle response by the presentation of a weak sound, a prepulse, was also measured. Two groups of 30 adults (young and older adults) viewed pleasant, neutral, and unpleasant images from the International Affective Picture System (IAPS) while startle and prepulse trials were presented. The results show that the startle response is differently modulated in the two groups, with the elderly displaying a greater startle reflex while viewing pleasant and neutral pictures compared to young adults. Prepulse inhibition is also differently modulated by emotions in young adults and their older counterparts, with the latter exhibiting a greater inhibition of the startle reflex when viewing pleasant and unpleasant pictures (but not for neutral pictures) compared to young adults. In summary, the present data do not support a decline of the inhibitory function with increasing age, but rather support a positivism effect.
45

Efeitos das intervenções psicomotoras no equilíbrio do idoso com déficit cognitivo leve: quase experimento

Ferreira, Josélia Braz dos Santos January 2014 (has links)
Submitted by Fabiana Gonçalves Pinto (benf@ndc.uff.br) on 2015-10-16T15:19:42Z No. of bitstreams: 1 Josélia Braz dos Santos Ferreira.pdf: 3515861 bytes, checksum: 7ce85c03078e93aebb216e487af5816e (MD5) / Made available in DSpace on 2015-10-16T15:19:42Z (GMT). No. of bitstreams: 1 Josélia Braz dos Santos Ferreira.pdf: 3515861 bytes, checksum: 7ce85c03078e93aebb216e487af5816e (MD5) Previous issue date: 2014 / Mestrado Acadêmico em Ciências do Cuidado em Saúde / Trata-se de um estudo quantitativo com uma abordagem quase experimental, cujo objetivo geral foi analisar os efeitos das atividades psicomotoras para o equilíbrio em idosos com distúrbio cognitivo leve e os objetivos específicos foram identificar o déficit psicomotor nos idosos com Déficit Cognitivo Leve utilizando a Escala Motora para a Terceira Idade (EMTI) e a Escala de Tinetti; implementar atividades e exercícios psicomotores para o idoso com Déficit Cognitivo Leve visando a melhora dos fatores psicomotores com ênfase ao equilíbrio e marcha; comparar as condições psicomotoras dos idosos com Déficit Cognitivo Leve antes e após a implementação de atividades e exercícios psicomotores. A pesquisa foi realizada em um período de 4 (quatro) meses, com início em abril de 2014 e término em julho de 2014. Os sujeitos do estudo foram 43 idosos de duas instituições públicas, na faixa etária entre 64 a 88 anos, 86,04% do sexo feminino. O estudo desenvolveu metas que foram cumpridas de acordo com a Teoria do Alcance de Metas de Imogene King. Foi aplicado o MEEM (Mini Exame do Estado Mental) em todos os idosos para avaliação da memória. Para avaliar os parâmetros motores foi utilizada a Escala Motora para Terceira Idade (EMTI) e para avaliar o Equilíbrio e a Marcha, a Escala de Tinetti; foi utilizado também o Diário de Quedas do Idoso. As escalas foram aplicadas antes e após a implementação das atividades psicomotoras, que foram realizadas durante 10 (dez) sessões. Nos resultados, utilizou-se do software estatístico SAS versão 9.3.1, tal que primeiramente realizou-se uma análise descritiva dos dados, dividindo em primeira medida (primeira avaliação) e segunda medida (segunda avaliação). A avaliação do MEEM mostrou 15 (quinze), 34,88%, dos idosos avaliados apresentaram sinais sugestivos de déficit cognitivo. Resultados relacionados ao desempenho dos idosos nos parâmetros motores Motricidade Fina, Organização Espacial e Organização temporal, tanto na primeira como na segunda medidas apresentaram bons resultados e ficaram na classificação normal médio da EMTI. No entanto, na primeira avaliação, os parâmetros Motricidade Global, obteve média de 34,88 pontos, equivalente a classificação muito inferior; o Esquema Corporal com média de 76,46 pontos correspondeu a classificação inferior; e também o Equilíbrio com média de 79,81 pontos ficou na classificação inferior. Estes resultados corresponderam aos resultados do Equilíbrio e Marcha da Escala de Tinetti, que apresentou 22 (51,16%) idosos com média de 17,22 pontos e ficaram, segundo a escala, com alto risco para quedas. Os resultados destas escalas foram corroborados com os resultados do Diário de Quedas dos Idosos, onde 26 (60,47%) idosos sofreram 52 quedas, sendo que 33 (63,46%) quedas ocorreram por desequilíbrios e 31 (59,62%) quedas foram na rua. Na segunda avaliação após as atividades implementadas, os idosos apresentaram melhores resultados com mudança da classificação de acordo com os escores, exceto a Motricidade Global, que permaneceu na classificação muito inferior. No entanto, o Esquema Corporal mudou para a classificação normal baixo com média de 86,93 pontos, o Equilíbrio mudou da classificação inferior para normal médio com média de 92,37 pontos. O Equilíbrio e marcha da Escala de Tinetti apresentou aumento em seus escores e a maioria dos idosos, 28 (65,11%), ficaram com risco moderado para quedas segundo a escala. Concluiu-se com os resultados na segunda medida, que as metas foram alcançadas e a hipótese de que o exercício de estimulação psicomotora favorece o equilíbrio de idosos com distúrbio cognitivo leve foi confirmada / This is a quantitative study with a quasi-experimental approach, whose general objective was to analyze the effects of psychomotor activities for balance in elderly people with mild cognitive impairment and specific objectives were to identify the psychomotor deficit in the elderly with mild cognitive deficit using the Scale motor for the Elderly (EMTI) and the Tinetti scale; implement activities and psychomotor exercises for the elderly with Mild Cognitive Deficit aimed at improving the psychomotor factors with emphasis on balance and gait; compare psychomotor conditions of elderly people with Mild Cognitive Deficit before and after the implementation of activities and psychomotor exercises. The survey was conducted over a period of four (4) months, starting in April 2014 and ending in July 2014. The study subjects were 43 elderly two public institutions, aged between 64 and 88 years, 86, 04% female. The study developed goals that were performed in accordance with the Scope of the Theory of Imogene King Goals. The MMSE (Mini Mental State Examination) in all the elderly to assess memory was applied. To evaluate the motor parameters we used the Motor Scale for the Elderly (EMTI) and to assess the balance and the March, the Tinetti Scale; we used the Elderly Falls Journal. The scales were applied before and after the implementation of psychomotor activities, which were performed for 10 (ten) sessions. In the results, we used the SAS statistical software version 9.3.1, such that first carried out a descriptive analysis of data, sharing in a first step (first evaluation) and second measurement (second evaluation). The assessment of the MMSE was 15 (fifteen), 34.88% of the sample respectively showed signs suggestive of cognitive impairment. Results related to the performance of the elderly in the parameters Motricity Thin engines, Space Organization and temporal organization, both in the first and second measurements showed good results and were in the normal average rating of EMTI. However, the first evaluation, the Global Kinetics parameters obtained an average of 34.88 points, equivalent to much lower rating; the Body Scheme averaging 76.46 points corresponded to a lower classification; and also the balance with an average of 79.81 points was in a lower classification. These results corresponded to the results of Balance and Gait Tinetti Scale, which showed 22 (51.16%) elderly with an average of 17.22 points and were, according to the scale at high risk for falls. The results of these scales were corroborated by the results of the Seniors' Falls Gazette, where 26 (60.47%) elderly suffered 52 falls, of which 33 (63.46%) decreases occurred by imbalances and 31 (59.62%) falls were in the street. In the second evaluation after the implemented activities, the elderly showed better results with rating change according to the scores, except the Global Mobility, which remained much lower rating. However, the Body Scheme moved to low normal rating with an average of 86.93 points, the balance changed the lower rating for average normal with an average of 92.37 points. The Balance and Gait Tinetti Scale showed an increase in their scores and most elderly, 28 (65.11%) were at moderate risk for falls under the scale. Concluded with the results in the second measure, which targets have been achieved and the hypothesis that the psychomotor stimulation exercise favors the balance of elderly patients with mild cognitive impairment was confirmed
46

Acquired flatfoot in adults / Acquired flatfoot in adults

Khadura, Mohamed January 2017 (has links)
Title: Acquired flatfoot in adults Background: Flatfoot deformity is one of the common diagnoses in the orthopedic field and physiotherapy, its common in adults as acquired, there is still a large incidence of flatfoot in adolescence and many cases of adult flatfoot are frequently presented as residual pediatric flatfoot. The treatment also has wide field according to type of cause. Aims: The aim of this literature review was to enhance knowledge on the persistence of the acquired flatfoot condition in adult's population by determining the causes of flatfoot with contributing factors that affect the medial longitudinal arch and progression of the deformity, and review of the most common treatment. Method: An electronic database search was conducted to obtain articles from relevant journals (from early 1990 to end 2015). The information was collected also from textbooks. Results: Regarding the causes of acquired flatfoot in adult, a good base of evidence stems from a number of articles review, the posterior tibialis tendon dysfunction is the most cause of acquired flatfoot. The sensory motor stimulation technique is not the most treatment used to treat acquired flatfoot in adults and the most used treatment is the surgical procedure. Conclusion: Regarding the causes of adults acquired flatfoot in...
47

Holding hands for sustainable change in disadvantaged Educare centres through volunteer teaching

Gwyn, Rosemary January 2001 (has links)
Magister Educationis - MEd / This thesis is a record and analysis of as well as a commentary on an emancipatory.educational action research project in which I participated at three educare centres serving 0 - 6 year old children in Nyanga, Philippi and Old Crossroads of Cape Town, South Africa. The study sprang from my need to examine closely the work I was doing as a volunteer in the hope of maximizing my efforts to bring about sustainable change in these challenging settings. . Ultimately my goal was safe, healthy and stimulating educare. I chose what I perceived to be a few important areas for improvement which reflected both the teachers' prior educare training as offered in several non-governmental organizations in Cape Town as well as ideas which I contributed from my own readings and studies. Room arrangement to ease flow and promote independent, individual learning was one area. Establishing routines in a daily programme that encouraged children to become interested and responsible members of the educare community, that fairly divided teacher tasks and that increased child/teacher interactions was another area for improvement. The thesis includes a discussion in Chapter 3 of emancipatory educational action research as a good vehicle for the work I undertook with all the teachers in each of the three centres. Central to this choice was my participation in change including change within myself as a volunteer in-service field worker. Flexibility in timing, including delays and many repetitions, were a feature of my work with women whose lives of grinding poverty were at the mercy of tragedy and disaster as well as time-consuming tasks making for absenteeism. The main benefit of this form of research was its potential for growth in self-esteem and empowerment in individual teachers as they witnessed the benefits of their planned work multiply at the centres. I divided the work at each centre into three phases. The first included getting to know the centre, its teachers and children and making decisions around what tasks to undertake. In the same phase the teachers and I began to work on the identified areas. In the second phase, I introduced the teachers to teachers at other successful educare centres so that linkages could be established that would strengthen the work we were doing and broaden their base of support. Ultimately, I intended that this would allow me to decrease my presence and input gradually while change continued at the three centres. The third phase involved the teachers at a centre plowing back their new skills into the wider network of Mustadafin Foundation educare centres in which they were involved and which needed similar assistance. I have presented a new understanding for sustainable change resulting from this study and it is my hope that donors and others involved in community upliftment will understand that continued input and follow-up involvement need to accompany material gifts and intensive upgrading. Finally, I have written what I hope is a very readable thesis so that the teachers involved can read their own and each others' stories as I have done my best to record and interpret them.
48

Modulation du réflexe acoustique de sursaut et de l’inhibition par le prépulse : une comparaison entre les jeunes adultes et les âgés

Le Duc, Jolyanne 08 1900 (has links)
No description available.
49

Toward Building A Social Robot With An Emotion-based Internal Control

Marpaung, Andreas 01 January 2004 (has links)
In this thesis, we aim at modeling some aspects of the functional role of emotions on an autonomous embodied agent. We begin by describing our robotic prototype, Cherry--a robot with the task of being a tour guide and an office assistant for the Computer Science Department at the University of Central Florida. Cherry did not have a formal emotion representation of internal states, but did have the ability to express emotions through her multimodal interface. The thesis presents the results of a survey we performed via our social informatics approach where we found that: (1) the idea of having emotions in a robot was warmly accepted by Cherry's users, and (2) the intended users were pleased with our initial interface design and functionalities. Guided by these results, we transferred our previous code to a human-height and more robust robot--Petra, the PeopleBot™--where we began to build a formal emotion mechanism and representation for internal states to correspond to the external expressions of Cherry's interface. We describe our overall three-layered architecture, and propose the design of the sensory motor level (the first layer of the three-layered architecture) inspired by the Multilevel Process Theory of Emotion on one hand, and hybrid robotic architecture on the other hand. The sensory-motor level receives and processes incoming stimuli with fuzzy logic and produces emotion-like states without any further willful planning or learning. We will discuss how Petra has been equipped with sonar and vision for obstacle avoidance as well as vision for face recognition, which are used when she roams around the hallway to engage in social interactions with humans. We hope that the sensory motor level in Petra could serve as a foundation for further works in modeling the three-layered architecture of the Emotion State Generator.
50

Apprentissage ouvert de representations et de fonctionnalites en robotique : anayse, modeles et implementation

PAQUIER, Williams 19 March 2004 (has links) (PDF)
L'acquisition autonome de representations et de fonctionnalites en robotique pose de nombreux problemes theoriques. Aujourd'hui, les systemes robotiques autonomes sont concus autour d'un ensemble de fonctionnalites. Leurs representations du monde sont issues de l'analyse d'un probleme et d'une modelisation prealablement donnees par les concepteurs. Cette approche limite les capacites d'apprentissage. Nous proposons dans cette these un systeme ouvert de representations et de fonctionnalites. Ce systeme apprend en experimentant son environnement et est guide par l'augmentation d'une fonction de valeur. L'objectif du systeme consiste a agir sur son environnement pour reactiver les representations dont il avait appris une connotation positive. Une analyse de la capacite a generaliser la production d'actions appropriees pour ces reactivations conduit a definir un ensemble de proprietes necessaires pour un tel systeme. Le systeme de representation est constitue d'un reseau d'unites de traitement semblables et utilise un codage par position. Le sens de l'etat d'une unite depend de sa position dans le reseau. Ce systeme de representation possede des similitudes avec le principe de numeration par position. Une representation correspond a l'activation d'un ensemble d'unites. Ce systeme a ete implemente dans une suite logicielle appelee NeuSter qui permet de simuler des reseaux de plusieurs millions d'unites et milliard de connexions sur des grappes heterogenes de machines POSIX. Les premiers resultats permettent de valider les contraintes deduites de l'analyse. Un tel systeme permet d'apprendre dans un meme reseau, de facon hierarchique et non supervisee, des detecteurs de bords et de traits, de coins, de terminaisons de traits, de visages, de directions de mouvement, de rotations, d'expansions, et de phonemes. NeuSter apprend en ligne en utilisant uniquement les donnees de ses capteurs. Il a ete teste sur des robots mobiles pour l'apprentissage et le suivi d'objets.

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