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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.
441

Representação de conhecimento : programação em lógica e o modelo das hiperredes / Knowledge representation: logic programming and the hypernets model

Palazzo, Luiz Antonio Moro January 1991 (has links)
Apesar de sua inerente indecidibilidade e do problema da negação, extensões da lógica de primeira ordem tem se mostrado capazes de superar a questão da monotonicidade, vindo a constituir esquemas de representação de conhecimento de expressividade virtualmente universal. Resta entretanto solucionar ou pelo menos amenizar as conseqüências do problema do controle, que limitam o seu emprego a aplicações de pequeno a médio porte. Investigações nesse sentido [BOW 85] [MON 88] indicam que a chave para superar a explosão inferencial passa obrigatoriamente pela estruturação do conhecimento, de modo a permitir o exercício de algum controle sobre as possíveis derivações dele decorrentes. O modelo das hiperredes [GEO 85] parece atingir tal objetivo, dado o seu elevado potencial de estruturação e o instrumental que oferece para o tratamento de construções descritivas, operacionais e organizacionais. Além disso, a simplicidade e uniformidade sintática de suas entidades primitivas possibilita uma interpretação semântica bastante clara do modelo original, por exemplo, baseada em grafos. O presente trabalho representa uma tentativa de associar a programação em lógica ao formalismo das hiperredes, visando obter um novo modelo capaz de preservar as expressividade da primeira, beneficiando-se simultaneamente do potencial heurístico e estrutura do segundo. Inicialmente procura-se obter uma noção clara da natureza do conhecimento e de seus mecanismos com o objetivo de caracterizar o problema da representação de conhecimento. Diferentes esquemas correntemente empregados para esse fim (sistemas de produções, redes semânticas, sistemas de frames, programação em lógica e a linguagem Krypton) são estudados e caracterizados do ponto de vista de sua expressividade, potencial heurístico e conveniência notacional. A programação em lógica é objeto de um estudo em maior profundidade, sob os enfoques modelo-teorético e prova-teorético. Sistemas de programação em lógica - particularmente a linguagem Prolog e extensões em nível meta - são investigados como esquemas de representação de conhecimento, considerando seus aspectos sintáticos e semânticos e a sua retação com Sistemas Gerenciadores de Bases de Dados. O modelo das hiperredes é apresentado introduzindo-se, entre outros, os conceitos de hipernodo, hiperrelação e protótipo, assim como as propriedades particutares de tais entidades. A linguagem Hyper, para o tratamento de hiperredes, é formalmente especificada. Emprega-se a linguagem Prolog como formalismo para a representação de Bases de Conhecimento estruturadas segundo o modelo das hiperredes. Sob tal abordagem uma Base de Conhecimento é vista como um conjunto (possivelmente vazio) de objetos estruturados ou peças de conhecimento, que por sua vez são classificados como hipernodos, hiperrelações ou protótipos. Um mecanismo top-down para a produção de inferências em hiperredes é proposto, introduzindo-se os conceitos de aspecto e visão sobre hiperredes, os quais são tomados como objetos de primeira classe, no sentido de poderem ser valores atribuídos a variáveis. Estuda-se os requisitos que um Sistema Gerenciador de Bases de Conhecimento deve apresentar, do ponto de vista da aplicação, da engenharia de conhecimento e da implementação, para suportar efetivamente os conceitos e abstrações (classificação, generalização, associação e agregação) associadas ao modelo proposto. Com base nas conclusões assim obtidas, um Sistema Gerenciador de Bases de Conhecimento (denominado Rhesus em alusão à sua finalidade experimental é proposto e especificado, objetivando confirmar a viabilidade técnica do desenvolvimento de aplicações baseadas em lógica e hiperredes. / In spite of its inherent undecidability and the negation problem, extensions of first-order logic have been shown to be able to overcome the question of the monotonicity, establishing knowledge representation schemata with virtuatLy universal expressiviness. However, one still has to solve, or at Least to reduce the consequences of the control problem, which constrains the use of Logic-based systems to either small or medium-sized applications. Investigations in this direction [BOW 85] [MON 88] indicate that the key to overcome the inferential explosion resides in the proper knowledge structure representation, in order to have some control over possible derivations. The Hypernets Model [GEO 85] seems to reach such goat, considering its high structural power and the features that it offers to deal with descriptive, operational and organizational knowledge. Besides, the simplicity and syntactical uniformity of its primitive notions allows a very clear definition for its semantics, based, for instance, on graphs. This work is an attempt to associate logic programming with the hypernets formalism, in order to get a new model, preserving the expressiveness of the former and the heuristic and structural power of the latter. First we try to get a clear notion of the nature of knowledge and its main aspects, intending to characterize the knowledge representation problem. Some knowledge representation schemata (production systems, semantic networks, frame systems, Logic programming and the Krypton Language) are studied and characterized from the point of view of their expressiveness, heuristic power and notational convenience. Logic programming is the subject of a deeper study, under the model-theoretic and proof-theoretic approaches. Logic programming systems - in particular the Prolog Language and metateuel extensions- - are investigated as knowledge representation schemata, considering its syntactic and semantic aspects and its relations with Data Base Management Systems. The hypernets model is presented, introducing the concepts of hypernode, hyperrelation and prototype, as well as the particular properties of those entities. The Hyper language, for the handling of h y pernets, is formally specified. Prolog is used as a formalism for the representation of Knowledge Bases which are structured as hypernets. Under this approach a Knowledge Brie is seen rrG a (possibly empty) set of structured objects, which are classified as hypernodes, hyperreLations or prototypes. A mechanism for top-down reasoning on hypernets is proposed, introducing the concepts of aspect and vision, which are taken as first-class objects in the sense that they could be (-Ysigned as values to variables. We study the requirements for the construction of a Knowledge Base Management System from the point of view of the user's need-1', knowledge engineering support and implementation issues, actually supporting the concepts and abstractions (classification, generalization, association and aggregation) rYsociated with the proposed model. Based on the conclusions of this study, a Knowledge Base Management System (called Rhesus, refering to its experimental objectives) is proposed, intending to confirm the technical viability of the development of applications based on logic and hypernets.
442

Avaliação do uso de linguagem documentária em catálogos coletivos de bibliotecas universitárias : um estudo sociocognitivo com protocolo verbal /

Boccato, Vera Regina Casari. January 2009 (has links)
Orientador: Mariângela Spotti Lopes Fujita / Banca: Isidoro Gil Leiva / Banca: Maria Cristiane Barbosa Galvão / Banca: Maria de Fátima Gonçalves Moreira Tálamo / Banca: Plácida Leopoldina Ventura Amorim da Costa Santos / Resumo: A linguagem documentária desempenha um papel fundamental na indexação e recuperação da informação. Quando a linguagem documentária não corresponde às necessidades de representação dos conteúdos dos documentos, realizada pelos bibliotecários indexadores e das solicitações de buscas bibliográficas por assunto dos usuários, afeta a atuação desses processos, comprometendo a realização de buscas e serviços. Realizou-se, como proposta, um estudo de avaliação do uso de linguagem documentária alfabética de catálogos coletivos online, com enfoque nas tecnologias de representação e recuperação da informação, na perspectiva das bibliotecas universitárias e no contexto sociocognitivo de bibliotecários indexadores e usuários. Com o objetivo geral de contribuir para o uso adequado de linguagens documentárias alfabéticas nos processos de indexação e recuperação da informação de áreas científicas especializadas em catálogos coletivos de bibliotecas universitárias e, deste modo, colaborar com o processo de mudanças contínuas nos fazeres bibliotecários e, consequentemente, nos de sua comunidade usuária, a pesquisa teve como objetivos específicos: discutir o papel das linguagens documentárias alfabéticas na concepção dos catálogos coletivos pela perspectiva dos catálogos online; apresentar e discutir os estudos de avaliação de linguagens documentárias pelas abordagens quantitativas, qualitativas e qualitativas-cognitivas como métodos de avaliação, subsidiados pelos fundamentos teóricos e metodológicos da área de Organização e Representação do Conhecimento, frente aos paradigmas contemporâneos da área de Ciência da Informação; e investigar a aplicação da metodologia qualitativa de abordagem sociocognitiva mediante Protocolo Verbal para estudo de avaliação do uso de linguagem documentária alfabética de catálogos coletivos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The indexing language plays a fundamental role in the indexing and information retrieval. When the indexing language does not correspond to the necessities of representation of the contents of the documents, carried out by the indexers and the requests of bibliographical searches through the users' subject, it affects the performance of those processes, compromising the accomplishment of searches and services. The proposal is to carry through an evaluation study of the alphabetic indexing language use of the online collective catalogs, with a main focus on the technologies of representation and information retrieval, in the perspective of the university libraries and in the socio-cognitive context of indexers and users. With the general objective of to contribute for the adequate use of the alphabetical indexing languages in the indexing and information retrieval processes of specialized scientific areas in collective catalogs of the university libraries and thus, to collaborate with the process of continuous changes in the librarians' practice and, consequently, of its using community, the research had as specific objectives: arguing the role of the alphabetical indexing languages in the conception of the collective catalogs through the perspective of the online catalogs; presenting and arguing about the indexing languages evaluation studies through the quantitave, qualitative and qualitative-cognitive approaches as evaluation methods, which are supported by the theoretical and methodological fundamentals of the Organization and Knowledge Representation area, coping with the contemporary paradigms of the Information Science area ; and investigating the application of the socio-cognitive approach by Verbal Protocol for an evaluation study of the alphabetical indexing language use of the collective catalogs in specialized scientific areas in the perspective of the university libraries... (Complete abstract click electronic access below) / Doutor
443

Task-oriented communicative capabilities of agents in collaborative virtual environments for training / Des agents avec des capacités communicatives orientées tâche dans les environnements de réalité virtuelle collaboratifs pour l'apprentissage

Barange, Mukesh 12 March 2015 (has links)
Les besoins croissants en formation et en entrainement au travail d’équipe ont motivé l’utilisationd’Environnements de réalité Virtuelle Collaboratifs de Formation (EVCF) qui permettent aux utilisateurs de travailler avec des agents autonomes pour réaliser une activité collective. L’idée directrice est que la coordination efficace entre les membres d’une équipe améliore la productivité et réduit les erreurs individuelles et collectives. Cette thèse traite de la mise en place et du maintien de la coordination au sein d’une équipe de travail composée d’agents et d’humains interagissant dans un EVCF.L’objectif de ces recherches est de doter les agents virtuels de comportements conversationnels permettant la coopération entre agents et avec l’utilisateur dans le but de réaliser un but commun.Nous proposons une architecture d’agents Collaboratifs et Conversationnels, dérivée de l’architecture Belief-Desire-Intention (C2-BDI), qui gère uniformément les comportements délibératifs et conversationnels comme deux comportements dirigés vers les buts de l’activité collective. Nous proposons un modèle intégré de la coordination fondé sur l’approche des modèles mentaux partagés, afin d’établir la coordination au sein de l’équipe de travail composée d’humains et d’agents. Nous soutenons que les interactions en langage naturel entre les membres d’une équipe modifient les modèles mentaux individuels et partagés des participants. Enfin, nous décrivons comment les agents mettent en place et maintiennent la coordination au sein de l’équipe par le biais de conversations en langage naturel. Afin d’établir un couplage fort entre la prise de décision et le comportement conversationnel collaboratif d’un agent, nous proposons tout d’abord une approche fondée sur la modélisation sémantique des activités humaines et de l’environnement virtuel via le modèle mascaret puis, dans un second temps, une modélisation du contexte basée sur l’approche Information State. Ces représentations permettent de traiter de manière unifiée les connaissances sémantiques des agents sur l’activité collective et sur l’environnement virtuel ainsi que des informations qu’ils échangent lors de dialogues.Ces informations sont utilisées par les agents pour la génération et la compréhension du langage naturel multipartite. L’approche Information State nous permet de doter les agents C2BDI de capacités communicatives leur permettant de s’engager pro-activement dans des interactions en langue naturelle en vue de coordonner efficacement leur activité avec les autres membres de l’équipe. De plus, nous définissons les protocoles conversationnels collaboratifs favorisant la coordination entre les membres de l’équipe. Enfin, nous proposons dans cette thèse un mécanisme de prise de décision s’inspirant de l’approche BDI qui lie les comportements de délibération et de conversation des agents. Nous avons mis en oeuvre notre architecture dans trois différents scénarios se déroulant dans des EVCF. Nous montrons que les comportements conversationnels collaboratifs multipartites des agents C2BDI facilitent la coordination effective de l’utilisateur avec les autres membres de l’équipe lors de la réalisation d’une tâche partagée. / Growing needs of educational and training requirements motivate the use of collaborative virtual environments for training (CVET) that allows human users to work together with autonomous agents to perform a collective activity. The vision is inspired by the fact that the effective coordination improves productivity, and reduces the individual and team errors. This work addresses the issue of establishing and maintaining the coordination in a mixed human-agent teamwork in the context of CVET. The objective of this research is to provide human-like conversational behavior of the virtual agents in order to cooperate with a user and other agents to achieve shared goals.We propose a belief-desire-intention (BDI) like Collaborative Conversational agent architecture(C2BDI) that treats both deliberative and conversational behaviors uniformly as guided by the goal-directed shared activity. We put forward an integrated model of coordination which is founded on the shared mental model based approaches to establish coordination in a human-agent teamwork. We argue that natural language interaction between team members can affect and modify the individual and shared mental models of the participants. Finally, we describe the cultivation of coordination in a mixed human-agent teamwork through natural language conversation. In order to establish the strong coupling between decision making and the collaborative conversational behavior of the agent, we propose first, the Mascaret based semantic modeling of human activities and the VE, and second, the information state based context model. This representation allows the treatment of semantic knowledge of the collaborative activity and virtual environment, and information exchanged during the dialogue conversation in a unified manner. This knowledge can be used by the agent for multiparty natural language processing (understanding and generation) in the context of the CEVT. To endow the communicative capabilities to C2BDI agent, we put forward the information state based approach for the natural language processing of the utterances. We define collaborative conversation protocols that ensure the coordination between team members. Finally, in this thesis, we propose a decision making mechanism, which is inspired by the BDI based approach and provides the interleaving between deliberation and conversational behavior of the agent. We have applied the proposed architecture to three different scenarios in the CVET. We found that the multiparty collaborative conversational behavior of C2BDI agent is more constructive and facilitates the user to effectively coordinate with other team members to perform a shared task.
444

Decision support in dementia care : developing systems for interactive reasoning

Lindgren, Helena January 2007 (has links)
Demensvården i Sverige och i andra delar av världen har på olika sätt varit i fokus de senaste åren där man påtalat behovet att utveckla metoder och riktlinjer för hur vården ska bedrivas. Detta för att möta den växande andelen äldre människor som också utvecklar demenssjukdomar. Nationella projekt har drivits, företrädesvis i syfte att förbättra vård och omsorg av personer med demenssjukdom, men även för att förbättra diagnosticering och behandling. I denna avhandling beskrivs utvecklingen av det dator-baserade beslutsstödet för demensutredning, DMSS (Dementia Management and Support System), som syftar till att fungera som ett stöd för personer som arbetar med att diagnosticera och behandla personer med kognitiv sjukdom. Domänen valdes även på grund av dess komplicerade kunskapsinnehåll, där bland annat en spännvidd av olika typer av symptom, komplexa kliniska mätmetoder sett ur ett formaliseringsperspektiv, starkt teamorienterat arbetssätt, ställer krav på hur kunskap ska och är möjlig att formaliseras och integreras i ett beslutsstödsystem för att det ska bli användbart i kliniskt arbete. De olika studierna och delprojekten som beskrivs i avhandlingen syftar till att tillsammans skapa en grund för utveckling av ett kliniskt kognitivt verktyg som stödjer och utvecklar användarens kognitiva processer (lärande, beslutsfattande, resonemang, etc.), samtidigt som det stödjer utvecklingen av det kliniska arbetet vari systemet ingår. I detta arbete fokuseras demensutredning som applikationsomr åde. Analyser har gjorts av den vidare användarkontexten, resonemangsprocesser, domän- och processkunskapen uttryckt i evidensbaserad litteratur och integrerad i klinisk praktik, terminologier samt formaliseringstekniker som kan hantera domänkunskapens egenskaper och användarsituationens krav. Prototyper har utvecklats och utvärderats i en iterativ process i samarbete med domänexperter, för användande i klinisk praktik i Sverige och Japan. För dessa studier har kvalitativa metoder använts i syfte att fånga så många olika aspekter som möjligt angående formalisering och interaktion, samt av praktiska skäl då det funnits begränsad tillgång till expertanvändare och patienter. Triangulering av metoder har tillämpats för att validera resultat. Kliniska utredningsverksamheter är komplexa processer, som är situerade, emergenta och styrda av individens behov, men även begränsade eller möjliggjorda av tillgängliga resurser på olika vårdnivåer i vårdprocessen. Det behövs metoder och verktyg som kan användas vid utveckling av system som syftar till att stödja dessa verksamheter. Det finns exempel på metoder som utvecklats för transformation av informell klinisk kunskap till en formell struktur som kan implementeras i ett beslutsstödsystem, där verktyg har utvecklats primärt i syfte att hjälpa kliniska experter att transformera sin kunskap till något en systemutvecklare kan använda. Den största nackdelen med dessa angreppssätt är att de är tidskrävande för experterna att sätta sej in i och använda. En metod har tillämpats i detta arbete där en teoribildning, som är gemensam för flera forskningsområden, använts för att strukturera klinisk process- och domänkunskap i en form som kan användas i formaliseringsarbete. Den konceptuella modellen av kliniskt arbete som utvecklats är baserad på verksamhetsteorin, kompletterad med general logics som kategoriskt, formellt teoretiskt ramverk för att möjliggöra transformationer mellan olika logiska språk och flexibel representation av riktlinjer och kunskap. Genom att göra en grundlig verksamhetsanalys utifrån ett aktivitetsperspektiv med hjälp av modellen, kan komponenter identifieras som kan formaliseras i en kunskapsbas och/eller kompletteras genom en design och implementation av ett gränssnitt som stödjer ett interaktivt resonemang och den kliniska processen. Resultatet av verkamhetsanalys och andra studier som presenteras i denna avhandling kommer att ligga till grund för vidare utveckling av DMSS för olika användarmiljöer, till att börja med i Sverige och Japan. Extensioner av systemet kommer att utvecklas som stödjer de olika ingående professionerna på olika vårdnivåer. Den konceptuella modellen kommer att utvecklas och tillämpas i framtida utvecklingsprojekt där beslutsstöd är en central komponent. Det formella ramverket kommer att utvecklas i syfte att kunna analysera och förfina kunskap i perspektivet av exempelvis olika set av kliniska riktlinjer som ställer olika krav på komplexitet hos logiken. Stödet till ett interaktivt resonemang vid användandet av systemet ska utvecklas med en kunskapsbas och ett dynamiskt gränssnitt speciellt utformat för ändamålet. Hittills har i första hand kvalitativa aspekter och syften varit i fokus i de olika projekten. Därför behöver varje utvecklingslinje ytterligare utvecklas med kvantitativa mål. Utvidgade utvärderingsstudier pågår, som syftar till att undersöka fördelning mellan olika nivåer av komplexitet hos patienter och vilken typ av stöd som behövs för respektive. När systemet är integrerat i daglig verksamhet kan faktorer som hur användande av systemet påverkar användaren och verksamheten undersökas. / There is a need to improve dementia care in Sweden. The main issues discussed are how to improve the competence of medical personnel and the quality of diagnosis and intervention. In this thesis the process of developing a decision-support system for the investigation of dementia is described, as one means to meet the need. The resulting prototype system DMSS (Dementia Management Support System) has been developed in cooperation with domain experts, and has been evaluated and redesigned in the process in an iterative development process. The process involves the assessment of evidence-based domain knowledge and its characteristics, the assessment of the procedural knowledge residing in clinical practice, and reasoning processes. Further, the terminology and main reasoning process integrated in the system have been validated. Qualitative methods have been used for these parts of the project for the purpose of assessing as many different aspects as possible, and for practical reasons due to the limited access to domain experts, patients and primary care physicians in the area. Triangulation of methods has been applied in order to validate results in the process. The development has been extended to also include prototypes for Japanese clinical environments. Clinical investigation activities are complex processes, which are situated, emergent and directed by the individual need of the patient, but also restricted or enhanced by the available resources at different points and at different care levels in the process. For the purpose of creating a system which provides support throughout the investigation process, the domain knowledge and the clinical investigation process was analysed and formalised in a conceptual model of clinical activity, developed based on activity theory and case studies of patients. The need for methods for the transformation of informal results from field studies into formal knowledge and design is addressed by providing the framework, which integrates the conceptual model of clinical activity and a method for the assessment and transformation of the knowledge to be integrated in a decision-support system. The model was used to identify actions and their characteristics suitable for formalisation in a decision-support system. Several sources of domain knowledge need to be integrated that express the knowledge differently, which increases the demands on a formalism for representation. The work towards formalising the diagnostic reasoning process in both typical and atypical patient's cases is presented, where the evidence in ambiguous cases is valued within different frames of references in order to improve specificity. Different logical frameworks have been applied, evaluated and developed using case studies of patients. Two lines of work towards a dementia logic and flexible guideline representation is presented; the defeasible, non-monotonic approach where many-valued dictionaries are used in a context-based argumentation framework; and the monotonic approach of integrating reasoning in a fundamental view of transformations between logics, using general logics as generalised and categorical framework.
445

Knowledge Representation Framework For A Web-based Intelligent Tutoring System For Engineering Courses

Bhaskerray, Bhatt Chetan 07 1900 (has links)
Tutoring is one of the most effective instruction methods. Computer as an Intelligent Tutor is an area of research since many decades. Technology advancement in Information and Communication Technology (ICT) can be used in developing Web – based Intelligent Tutoring System (WITS), which provides individualized tutoring at the same time to large number of students geographically distributed. Intelligent Tutoring System requires knowledge representation of expert, student and instructional strategy. While web technology promises many attractive features to build web based ITS, it would still be a challenge to represent knowledge objects that are scalable, reusable and platform independent. It is required to derive generalized knowledge representation framework which can be used in developing WITS for many courses. This research work proposes an instruction System Design (ISD) model based framework in development of WITS for Control Systems. ADDIE model is selected in development of WITS. Front end analysis is conducted to identify the learning goals of a course. Proposed research work presents a Bloom - Vincenti framework for preparing learning objectives for engineering courses. Problem Based Learning (PBL) is selected as instruction strategy. Then it presents an ontology based knowledge representation framework for expert module, tutoring module, and student module. Ontology for expert module is proposed on the course structure, instruction system, instruction material ontology, and Bloom – Vincenti Taxonomy. Ontology for student module is also proposed on course structure and Bloom – Vincenti Taxonomy. Tutoring module consists of ontology about the facts of the instruction material and rule base based on the categories of engineering knowledge (Vincenti) and cognitive skill (Bloom’s Taxonomy). Proposed way of knowledge representation supports scalability, and reusability. Prototype Web – based Intelligent Tutoring System for first level course on Control Systems is developed. JAVA technology used in development of Web – based Intelligent Tutoring System (WITS), makes WITS platform independent. Web – based Intelligent Tutoring System for Control Systems is deployed at laboratory level and its efficacy is tested for first two modules of a course.
446

Steuerung Alt Entfernen / Re-boot Science

Becker, Claudia 18 April 2013 (has links) (PDF)
Wissen, Wissenssammlungen und Wissensordnungen haben sich im Laufe der Jahre verändert, ebenso wie die Wissensproduktion, die Schaffung neuen Wissens, die Wissenschaft selbst. Der Baum des Wissens, arbor porphyriana oder auch arbor scientiae war seit der Antike eine gültige Metapher und das Klassifikationsschema für die Struktur des Wissens, die epistemologische Ordnung. So lehnte auch Denis Diderot die Ordnung seiner berühmten Enzyklopädie an die Baumstruktur des Wissens von Francis Bacon an. (...)
447

Open Models of Decision Support Towards a Framework

Diasio, Stephen Ray 14 June 2012 (has links)
Aquesta tesi presenta un marc per als models oberts de suport a les decisions en les organitzacions. El treball es vehicula a través d’un compendi d’articles on s’analitzen els fluxos d’entrada i de sortida de coneixement en les organitzacions, així como les tecnologies existents de suport a les decisions. Es presenten els factors subjacents que impulsen nous models per a formes obertes de suport a la decisió. La tesis presenta un estudi de les distintes tipologies de models de suport a les decisions tenint en compte diferents tipus d’organitzacions. En el primer estudi, paper#, es presenta l’evolució de les tecnologies de suport a les decisions i l’avançament de les noves tecnologies per als models oberts. Aquest estudi proporciona una visió des d’una perspectiva evolutiva de la relació entre el coneixement expert i la seva utilització en les tecnologies de suport a les decisions. La investigació revela l’entorn canviant que la tecnologia ofereix a l’hora de adquirir coneixement per a la presa de decisions i obre horitzons sobre el nou paper que els experts tenen en aquests entorns. Es suggereix que un canvi significatiu en la presa de decisions es basa en el desafiament entre el paper tradicional dels experts i no experts. Per últim, aquest treball explora les oportunitats d’integració de la intel•ligència artificial en la tecnologia de suport a les decisions i quins beneficis addicionals poden aportar les eines d’ intel•ligència col•lectiva en la presa de decisions. El segon estudi, paper#2, investiga sobre la tipologia anomenada "agregada" dins del marc d’entorns oberts per al suport a la presa de decisions. S’utilitza un problema de predicció com a fil conductor per a posar en relleu la complexitat de la previsió de la demanda dins de la industria del cinema. S’analitza com es pot utilitzar la tecnologia per a millorar l’eficàcia en les decisions. La investigació compara dues tecnologies de suport a les decisions: sistemes experts i eines d’intel•ligència col•lectiva, i il•lustra com l’industria del cinema utilitza cada una d’aquestes tecnologies en la previsió dels ingressos de taquilla. Per últim, aquest article explora els beneficis de l’ integració d’aquestes tecnologies de suport per a l’obtenció de prediccions més precises. El tercer estudi, article#3, presenta un estudi longitudinal durant un període de 10 anys que utilitza IBM “Innovation Jams” como un context per a la col•laboració a gran escala dins de la tipologia anomenada "plataforma". Aquest article investiga el paper de les “Innovation Jams”, en el canvi organitzacional i com IBM es compromet amb un nou model d’innovació en les organitzacions. En ell es descriuen les “Innovation Jams”, que han impulsat la innovació i consolidat la pràctica de la innovació oberta en IBM. En aquest article s’utilitza el gènere musical d’una "jamband" com una metàfora per a descriure el desenvolupament emergent i l’ús de les “Innovation Jams”, com una manera d’entendre el canvi organitzatiu. Aquest estudi longitudinal ofereix una visió actualitzada de la recerca en “Innovation Jams”, mostrant com han evolucionat des d’un concepte, a una eina de gestió i finalment a un servei. L’article conclou amb una discussió sobre les implicacions dels resultats i com aquests permeten teoritzar sobre nous models d’ innovació i el canvi en les organitzacions. La recerca duta a terme en aquesta tesi ofereix un marc per als models oberts de suport a la decisió, i suggereix que, les fonts internes i externes de coneixement poden ser utilitzades, més enllà de la innovació del producte o serveis, per a la presa de decisions amb el suport de tecnologies emergents. Les contribucions teòriques d’aquesta tesi sostenen que les organitzacions ja no poden confiar en la tecnologia de suport a les decisions que únicament es centren en la reducció de la frontera entre els aspectes racionals i no racionals de la conducta social humana, sinó que pel contrari, han de considerar la xarxa dinàmica de la organització per al suport a la decisió. D’altra banda, les implicacions pràctiques d’aquesta tesi animen les organitzacions a pensar estratègicament sobre com les tecnologies emergents poden ajudar en la presa de decisions i també com els models de decisió resultants poden ser utilitzats per a navegar per l’entorn complex existent, i, a la vegada, forjar vincles més forts amb els clients, proveïdors i la xarxa de l’organització. / Esta tesis presenta un marco para modelos abiertos de soporte a las decisiones en las organizaciones. El trabajo se vehicula a través de un compendio de artículos dónde se analizan los flujos de entrada y salida de conocimiento en las organizaciones, así como las tecnologías existentes de soporte a las decisiones. Se presentan los factores subyacentes que impulsan nuevos modelos para formas abiertas de soporte a la decisión. La tesis presenta un estudio de las distintas tipologías de modelos de soporte a las decisiones teniendo en cuenta distintos tipos de organizaciones. En el primer estudio paper#1 se presenta la evolución de las tecnologías de apoyo a las decisiones y el avance de las nuevas tecnologías para los modelos abiertos. Este estudio proporciona una visión desde una perspectiva evolutiva de la relación entre conocimiento experto y su utilización en las tecnologías de soporte a las decisiones. La investigación revela el entorno cambiante que la tecnología ofrece a la hora de adquirir conocimiento para la toma de decisiones y abre horizontes sobre el nuevo papel que los expertos tienen en estos entornos. Se sugiere que un cambio significativo en la toma de decisiones se basa en el desafío entre el papel tradicional de los expertos y no expertos. Por último, este trabajo explora las oportunidades de integración de la inteligencia artificial en la tecnología de soporte de decisiones y que beneficios adicionales pueden aportar las herramientas de inteligencia colectiva en la toma de decisiones. El segundo estudio, paper#2, investiga sobre la tipología llamada "agregada" dentro del marco de entornos abiertos para el soporte a la toma de decisiones. Se utiliza un problema de predicción como hilo conductor para poner en relieve la complejidad de la previsión de la demanda dentro de la industria del cine. Se analiza cómo se puede utilizar la tecnología para mejorar la eficacia en las decisiones. La investigación compara dos tecnologías de soporte a las decisiones: sistemas expertos y herramientas de inteligencia colectiva, e ilustra cómo la industria del cine utiliza cada una de estas tecnologías en la previsión de los ingresos de taquilla. Por último, este artículo explora los beneficios de la integración de estas tecnologías de apoyo para la obtención de predicciones más precisas. El tercer estudio, artículo #3, presenta un estudio longitudinal durante un período de 10 años que utiliza IBM “Innovation Jams”, como un contexto para la colaboración a gran escala dentro de la tipología llamada "plataforma". Este artículo investiga el papel de las “Innovation Jams”, en el cambio organizacional y como IBM se compromete con un nuevo modelo de innovación de la organización. En él se describen las “Innovation Jams”, que han impulsado la innovación y consolidado la práctica de la innovación abierta en IBM. En este artículo se utiliza el género musical de una "jamband" como una metáfora para describir el desarrollo emergente y el uso de las “Innovation Jams”, como una manera de entender el cambio organizativo. Este estudio longitudinal ofrece una visión actualizada de la investigación en “Innovation Jams”, mostrando cómo han evolucionado desde un concepto, a una herramienta de gestión y finalmente a un servicio. El artículo concluye con una discusión sobre las implicaciones de los resultados y como ellos permiten teorizar sobre nuevos modelos de innovación y el cambio en las organizaciones. La investigación llevada a cabo en esta tesis ofrece un marco para los modelos abiertos de apoyo a la decisión, y sugiere que el uso de fuentes internas y externas de conocimiento pueden ser utilizadas más allá de la innovación del producto o servicio para la toma de decisiones con el soporte de tecnologías emergentes. Las contribuciones teóricas de esta tesis sostienen que las organizaciones ya no pueden confiar en la tecnología de apoyo a las decisiones que únicamente se centran en la reducción de la frontera entre los aspectos racionales y no racionales de la conducta social humana, sino por el contrario, deben considerar la red dinámica de la organización para el apoyo a la decisión. Por otra parte, las implicaciones prácticas de esta tesis alienta a las organizaciones a pensar estratégicamente acerca de cómo las tecnologías emergentes pueden ayudar a la toma de decisiones y también cómo los modelos de decisión resultantes pueden ser utilizados para navegar por el entorno complejo existente y, a su vez, forjar vínculos más fuertes con los clientes, proveedores y más amplios de la red de la organización. / This thesis presents a framework for open models of decision support through a compendium of papers that links research on the inward and outward flows of knowledge to the organization and decision support technologies. The framework presents underlying factors driving new and more open models of decision support. A typology of decision support models is offered considering types of problems organizations and managers charged with decision-making face. Thesis essay #1 suggests a perspective of the changing landscape for decision support technology and the advancement of new technology for open models of decision support. This study provides insight from an evolutionary perspective of expertise that has shaped the field of decision support technologies. The investigation sets out to reveal the changing landscape of expertise in supporting decision-making using technology and sheds light on the new role that experts will play in organizational decision-making. It suggests that a significant change in how decision-making is being supported which challenge the traditional role of experts and non-experts. Finally, this paper explores opportunities for decision support technology integration and the added benefits artificial intelligence can bring to collective intelligence tools. Thesis essay #2 investigates the ‘aggregate’ typology within the open model decision support framework. A forecasting problem is used to highlight the complexity of demand forecasting in supply-chain management within the film industry and how technology is leveraged for effective supply-chain management decisions. The investigation compares two decision support technologies: expert systems and collective intelligence tools and illustrates how the film industry uses each in forecasting box-office revenue. Finally, this essay explores the combined benefits in integrating each support technology for more accurate forecasting. Thesis essay #3 is a longitudinal study over a 10 year period that uses IBM Innovation Jams as a context for large-scale collaboration within the ‘platform’ typology. This essay investigates the role of innovation jams on organizational change as IBM learned to engage with a new model of organizing innovation. It describes the role innovation jams have played in shaping the practice of open innovation at IBM. This essay uses the musical genre of a “jamband” as a metaphor to describe the emergent development and use of innovation jams as a way to understand organizational change. This longitudinal study brings innovation jam research up-to-date and presents innovation jams as they evolved from a concept, a management tool, and service. The essay concludes with a discussion on the implications of the findings for theorizing about new models of organizing innovation for organizational change. Research conducted in this thesis offers a framework of open models of decision support that suggests that the use of internal and external sources of knowledge can be leveraged beyond product or service innovation, to include decision-making supported by emerging technology. Theoretical contributions of this thesis argues that organizations can no longer rely on decision support technology that solely focus on bridging the boundary between rational and non-rational aspects of human social behavior but instead, must consider the larger dynamic organizational network for decision support. Moreover, practical implications of this thesis encourages organizations to think strategically about how emerging technology can support decision making and the resulting decision support models to navigate the complex environment they work in and in turn, to forge stronger links with customers, suppliers, and the wider organizational network.
448

Belief Change in Reasoning Agents / Axiomatizations, Semantics and Computations

Jin, Yi 26 January 2007 (has links) (PDF)
The capability of changing beliefs upon new information in a rational and efficient way is crucial for an intelligent agent. Belief change therefore is one of the central research fields in Artificial Intelligence (AI) for over two decades. In the AI literature, two different kinds of belief change operations have been intensively investigated: belief update, which deal with situations where the new information describes changes of the world; and belief revision, which assumes the world is static. As another important research area in AI, reasoning about actions mainly studies the problem of representing and reasoning about effects of actions. These two research fields are closely related and apply a common underlying principle, that is, an agent should change its beliefs (knowledge) as little as possible whenever an adjustment is necessary. This lays down the possibility of reusing the ideas and results of one field in the other, and vice verse. This thesis aims to develop a general framework and devise computational models that are applicable in reasoning about actions. Firstly, I shall propose a new framework for iterated belief revision by introducing a new postulate to the existing AGM/DP postulates, which provides general criteria for the design of iterated revision operators. Secondly, based on the new framework, a concrete iterated revision operator is devised. The semantic model of the operator gives nice intuitions and helps to show its satisfiability of desirable postulates. I also show that the computational model of the operator is almost optimal in time and space-complexity. In order to deal with the belief change problem in multi-agent systems, I introduce a concept of mutual belief revision which is concerned with information exchange among agents. A concrete mutual revision operator is devised by generalizing the iterated revision operator. Likewise, a semantic model is used to show the intuition and many nice properties of the mutual revision operator, and the complexity of its computational model is formally analyzed. Finally, I present a belief update operator, which takes into account two important problems of reasoning about action, i.e., disjunctive updates and domain constraints. Again, the updated operator is presented with both a semantic model and a computational model.
449

Advanced Reasoning about Dynamical Systems

Gu, Yilan 17 February 2011 (has links)
In this thesis, we study advanced reasoning about dynamical systems in a logical framework -- the situation calculus. In particular, we consider promoting the efficiency of reasoning about action in the situation calculus from three different aspects. First, we propose a modified situation calculus based on the two-variable predicate logic with counting quantifiers. We show that solving the projection and executability problems via regression in such language are decidable. We prove that generally these two problems are co-NExpTime-complete in the modified language. We also consider restricting the format of regressable formulas and basic action theories (BATs) further to gain better computational complexity for reasoning about action via regression. We mention possible applications to formalization of Semantic Web services. Then, we propose a hierarchical representation of actions based on the situation calculus to facilitate development, maintenance and elaboration of very large taxonomies of actions. We show that our axioms can be more succinct, while still using an extended regression operator to solve the projection problem. Moreover, such representation has significant computational advantages. For taxonomies of actions that can be represented as finitely branching trees, the regression operator can sometimes work exponentially faster with our theories than it works with the BATs current situation calculus. We also propose a general guideline on how a taxonomy of actions can be constructed from the given set of effect axioms. Finally, we extend the current situation calculus with the order-sorted logic. In the new formalism, we add sort theories to the usual initial theories to describe taxonomies of objects. We then investigate what is the well-sortness for BATs under such framework. We consider extending the current regression operator with well-sortness checking and unification techniques. With the modified regression, we gain computational efficiency by terminating the regression earlier when reasoning tasks are ill-sorted and by reducing the search spaces for well-sorted objects. We also study that the connection between the order-sorted situation calculus and the current situation calculus.
450

Ανάπτυξη και υλοποίηση δικτυακής πύλης αναζήτησης και εύρεσης βιβλίων βασισμένη σε τεχνολογίες Web 2.0 και σε οντολογίες με χαρακτήρα εξατομίκευσης

Καλού, Αικατερίνη 13 July 2010 (has links)
Στη παρούσα διπλωματική εργασία, πραγματοποιείται μία ποιοτική επισκόπηση του όρου Σημαντικός Ιστός και των τεχνολογιών αναπαράστασης γνώσης και συμπερασμού που υπόκεινται σε αυτόν, όπως οντολογίες, μέθοδοι και εργαλεία ανάπτυξης οντολογιών, γλώσσες αναπαράστασης οντολογιών καθώς και η επέκταση της εκφραστικότητας των οντολογιών με την προσθήκη κανόνων. Επίσης, γίνεται εκτενής αναφορά σε μία άλλη εξελικτική τάση, που κυριαρχεί στο χώρο του Web, το Web 2.0. Στα πλαίσια του Web 2.0, αναλύονται έννοιες όπως mashups και Web APIs. Ειδικά για την έννοια των Web APIs, γίνεται αναφορά και ανάλυση συγκεκριμένων APIs, όπως αυτά της Amazon και του EBay. Οι έννοιες του Σημαντικού Ιστού και του Web 2.0 παρουσιάζονται πολλές φόρες ως ανταγωνιστικές για το μέλλον του Ιστού. Εντούτοις, γίνεται σαφές όλο και περισσότερο ότι οι δύο αυτές έννοιες είναι συμπληρωματικές. Στα πλαίσια της διπλωματικής εργασίας, αναπτύχθηκε μια εφαρμογή η οποία θα συνδυάζει αυτές τις δύο κυρίαρχες τεχνολογικές τάσεις. Πιο συγκεκριμένα, η εφαρμογή αποτελεί ένα πλαίσιο αναζήτησης βιβλίων από το Amazon και το Half eBay με χαρακτήρα εξατομίκευσης. Για την εφαρμογή, κάθε χρήστης αποτελεί μία αυτόνομη οντότητα. Συνεπώς, το περιεχόμενο της εφαρμογής προσαρμόζεται ανάλογα με το προφίλ του χρήστη κάθε φορά. Η υλοποίηση της εφαρμογής στηρίζεται αποκλειστικά στην ανάπτυξη οντολογιών, στη συγγραφή κανόνων (για την εξατομίκευση), στη δημιουργία ενός mashup και στα Web APIs. Τέλος, να σημειωθεί ότι η εφαρμογή στηρίζεται σε μία κατανεμημένη αρχιτεκτονική 3-επιπέδων. / In the present diploma thesis, one qualitative review is realised for the concepts of Semantic Web and of technologies of representation of knowledge and reasoning that being in this, such as ontologies, methods and tools for ontology development, representation languages of ontologies as well as the extension of expressiveness of ontologies with the addition of rules. Also, it becomes an extensive report in an other evolutionary tendency, that dominates in the space of Web, Web 2.0. In the scope of Web 2.0, concepts such as mashups and Web APIs are analyzed. Specifically for the concept of Web APIs, we make a report and an analysis of concrete APIs, as those of Amazon and EBay. The concepts of Semantic Web and Web 2.0 are presented a lot of times as competitive for the future of Web. Nevertheless, it becomes more and more obvious that these two concepts are complemental. In the scope of these diploma thesis, was developed an application which combines these two dominant technological tendencies. In particular, the application constitutes a framework of searching books from Amazon and Half eBay with a personalised character. For the application, each user constitutes an autonomous entity. Consequently, the content of application is adapted depending on the profile of user each time. The implementation of application is supported exclusively in the ontology development, in the writing of rules (for the personalisation), in the creation of a mashup and in Web APIs. Finally, it is marked that the application is supported in a distributed 3-tier architecture.

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