176 research outputs found

    Bilingual sentence production and code-switching: Neural network simulations

    Get PDF

    Virtual Reality Games for Motor Rehabilitation

    Get PDF
    This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

    STOCHASTIC MOBILITY MODELS IN SPACE AND TIME

    Get PDF
    An interesting fact in nature is that if we observe agents (neurons, particles, animals, humans) behaving, or more precisely moving, inside their environment, we can recognize - tough at different space or time scales - very specific patterns. The existence of those patterns is quite obvious, since not all things in nature behave totally at random, especially if we take into account thinking species like human beings. If a first phenomenon which has been deeply modeled is the gas particle motion as the template of a totally random motion, other phenomena, like foraging patterns of animals such as albatrosses, and specific instances of human mobility wear some randomness away in favor of deterministic components. Thus, while the particle motion may be satisfactorily described with a Wiener Process (also called Brownian motion), the others are better described by other kinds of stochastic processes called Levy Flights. Minding at these phenomena in a unifying way, in terms of motion of agents \u2013 either inanimate like the gas particles, or animated like the albatrosses \u2013 the point is that the latter are driven by specific interests, possibly converging into a common task, to be accomplished. The whole thesis work turns around the concept of agent intentionality at different scales, whose model may be used as key ingredient in the statistical description of complex behaviors. The two main contributions in this direction are: 1. the development of a \u201cwait and chase\u201d model of human mobility having the same two-phase pattern as animal foraging but with a greater propensity of local stays in place and therefore a less dispersed general behavior; 2. the introduction of a mobility paradigm for the neurons of a multilayer neural network and a methodology to train these new kind of networks to develop a collective behavior. The lead idea is that neurons move toward the most informative mates to better learn how to fulfill their part in the overall functionality of the network. With these specific implementations we have pursued the general goal of attributing both a cognitive and a physical meaning to the intentionality so as to be able in a near future to speak of intentionality as an additional potential in the dynamics of the masses (both at the micro and a the macro-scale), and of communication as another network in the force field. This could be intended as a step ahead in the track opened by the past century physicists with the coupling of thermodynamic and Shannon entropies in the direction of unifying cognitive and physical laws

    An architectural selection framework for data fusion in sensor platforms

    Get PDF
    Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, February 2007.Includes bibliographical references (leaves 97-100).The role of data fusion in sensor platforms is becoming increasingly important in various domains of science, technology and business. Fusion pertains to the merging or integration of information towards an enhanced level of awareness. This thesis provides a canonical overview of several major fusion architectures developed from the remote sensing and defense community. Additionally, it provides an assessment of current sensors and their platforms, the influence of reliability measures, and the connection to fusion applications. We present several types of architecture for managing multi-sensor data fusion, specifically as they relate to the tracking-correlation function and blackboard processing representations in knowledge engineering. Object-Process Methods are used to model the information fusion process and supporting systems. Several mathematical techniques are shown to be useful in the fusion of numerical properties, sensor data updating and the implementation of unique detection probabilities. Finally, we discuss the importance of fusion to the concept and operation of the Semantic Web, which promises new ways to exploit the synergy of multi-sensor data platforms. This requires the synthesis of fusion with ontology models for knowledge representation. We discuss the importance of fusion as a reuse process in ontological engineering, and review key lifecycle models in ontology development. The evolutionary approach to ontology development is considered the most useful and adaptable to the complexities of semantic networks. Several potential applications for data fusion are screened and ranked according to the Joint Directors of Laboratories (JDL) process model for information fusion. Based on these predetermined criteria, the case of medical diagnostic imaging was found to offer the most promising applications for fusion, on which future product platforms can be built.by Atif R. Mirza.S.M

    Aerospace medicine and biology: A cumulative index to a continuing bibliography (supplement 345)

    Get PDF
    This publication is a cumulative index to the abstracts contained in Supplements 333 through 344 of Aerospace Medicine and Biology: A Continuing Bibliography. Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number, and accession number

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 341)

    Get PDF
    This bibliography lists 133 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during September 1990. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Visual attention and swarm cognition for off-road robots

    Get PDF
    Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2011Esta tese aborda o problema da modelação de atenção visual no contexto de robôs autónomos todo-o-terreno. O objectivo de utilizar mecanismos de atenção visual é o de focar a percepção nos aspectos do ambiente mais relevantes à tarefa do robô. Esta tese mostra que, na detecção de obstáculos e de trilhos, esta capacidade promove robustez e parcimónia computacional. Estas são características chave para a rapidez e eficiência dos robôs todo-o-terreno. Um dos maiores desafios na modelação de atenção visual advém da necessidade de gerir o compromisso velocidade-precisão na presença de variações de contexto ou de tarefa. Esta tese mostra que este compromisso é resolvido se o processo de atenção visual for modelado como um processo auto-organizado, cuja operação é modulada pelo módulo de selecção de acção, responsável pelo controlo do robô. Ao fechar a malha entre o processo de selecção de acção e o de percepção, o último é capaz de operar apenas onde é necessário, antecipando as acções do robô. Para fornecer atenção visual com propriedades auto-organizadas, este trabalho obtém inspiração da Natureza. Concretamente, os mecanismos responsáveis pela capacidade que as formigas guerreiras têm de procurar alimento de forma auto-organizada, são usados como metáfora na resolução da tarefa de procurar, também de forma auto-organizada, obstáculos e trilhos no campo visual do robô. A solução proposta nesta tese é a de colocar vários focos de atenção encoberta a operar como um enxame, através de interacções baseadas em feromona. Este trabalho representa a primeira realização corporizada de cognição de enxame. Este é um novo campo de investigação que procura descobrir os princípios básicos da cognição, inspeccionando as propriedades auto-organizadas da inteligência colectiva exibida pelos insectos sociais. Logo, esta tese contribui para a robótica como disciplina de engenharia e para a robótica como disciplina de modelação, capaz de suportar o estudo do comportamento adaptável.Esta tese aborda o problema da modelação de atenção visual no contexto de robôs autónomos todo-o-terreno. O objectivo de utilizar mecanismos de atenção visual é o de focar a percepção nos aspectos do ambiente mais relevantes à tarefa do robô. Esta tese mostra que, na detecção de obstáculos e de trilhos, esta capacidade promove robustez e parcimónia computacional. Estas são características chave para a rapidez e eficiência dos robôs todo-o-terreno. Um dos maiores desafios na modelação de atenção visual advém da necessidade de gerir o compromisso velocidade-precisão na presença de variações de contexto ou de tarefa. Esta tese mostra que este compromisso é resolvido se o processo de atenção visual for modelado como um processo auto-organizado, cuja operação é modulada pelo módulo de selecção de acção, responsável pelo controlo do robô. Ao fechar a malha entre o processo de selecção de acção e o de percepção, o último é capaz de operar apenas onde é necessário, antecipando as acções do robô. Para fornecer atenção visual com propriedades auto-organizadas, este trabalho obtém inspi- ração da Natureza. Concretamente, os mecanismos responsáveis pela capacidade que as formi- gas guerreiras têm de procurar alimento de forma auto-organizada, são usados como metáfora na resolução da tarefa de procurar, também de forma auto-organizada, obstáculos e trilhos no campo visual do robô. A solução proposta nesta tese é a de colocar vários focos de atenção encoberta a operar como um enxame, através de interacções baseadas em feromona. Este trabalho representa a primeira realização corporizada de cognição de enxame. Este é um novo campo de investigação que procura descobrir os princípios básicos da cognição, ins- peccionando as propriedades auto-organizadas da inteligência colectiva exibida pelos insectos sociais. Logo, esta tese contribui para a robótica como disciplina de engenharia e para a robótica como disciplina de modelação, capaz de suportar o estudo do comportamento adaptável.Fundação para a Ciência e a Tecnologia (FCT,SFRH/BD/27305/2006); Laboratory of Agent Modelling (LabMag

    Human-Computer Interaction

    Get PDF
    In this book the reader will find a collection of 31 papers presenting different facets of Human Computer Interaction, the result of research projects and experiments as well as new approaches to design user interfaces. The book is organized according to the following main topics in a sequential order: new interaction paradigms, multimodality, usability studies on several interaction mechanisms, human factors, universal design and development methodologies and tools

    Decision Support Systems

    Get PDF
    Decision support systems (DSS) have evolved over the past four decades from theoretical concepts into real world computerized applications. DSS architecture contains three key components: knowledge base, computerized model, and user interface. DSS simulate cognitive decision-making functions of humans based on artificial intelligence methodologies (including expert systems, data mining, machine learning, connectionism, logistical reasoning, etc.) in order to perform decision support functions. The applications of DSS cover many domains, ranging from aviation monitoring, transportation safety, clinical diagnosis, weather forecast, business management to internet search strategy. By combining knowledge bases with inference rules, DSS are able to provide suggestions to end users to improve decisions and outcomes. This book is written as a textbook so that it can be used in formal courses examining decision support systems. It may be used by both undergraduate and graduate students from diverse computer-related fields. It will also be of value to established professionals as a text for self-study or for reference
    corecore