• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 112
  • 33
  • 18
  • 8
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 256
  • 256
  • 204
  • 56
  • 53
  • 52
  • 42
  • 37
  • 36
  • 33
  • 32
  • 31
  • 29
  • 28
  • 27
  • 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.
161

Beslutsstödsystem Uppdragsplanering

Juhlin, Kent January 2015 (has links)
Detta arbete visar, delvis var för sig och delvis i kombination, hur regelbaserat och fallbaserat beslutsstöd kan användas vid uppdragsplanering. Uppdragsplanering utförs med hjälp av Mission Support System (MSS). Uppdragsplanering kräver en hel del arbete och en hel del erfarenhet för att den ska bli bra. Detta kan underlättas om man kan få hjälp av olika verktyg som kan dra nytta av uppsatta regler för respektive uppdrag och även dra nytta av tidigare uppdrag av samma karaktär. Sedan tidigare finns det två olika examensarbete som har undersökt respektive del av detta. Målet med detta arbete är delvis att demonstrera metoderna i en prototyp, var för sig och i kombination med varandra, och delvis att försöka besvara frågan om en kombination av metoderna presterar ett bättre beslutsstöd än när metoderna används var för sig. Detta arbete bygger på två tidigare examensarbeten. Metoden som används för att kunna bedöma vilken metod som är att föredra är att man har implementerat både verktygen i en prototyp. I prototypen planerar man sedan ett antal uppdrag och applicerar sedan dem olika metoderna var för sig och även i kombination och utvärderar resultatet. Resultatet pekar på att det ur planeringssynpunkt bör användas en kombination av de två presenterade metoderna. Däremot om man tar in tidsaspekten, så är den erfarenhetsbaserade metoden inte att rekommendera i det utförande som den är i nu. Detta eftersom den tar lång tid att applicera. Tidsåtgången är uppemot 12 timmar. Vilket inte fungerar i verkligheten. / This thesis shows, partly alone, partly in combination, how rule based and case based decision support can be used in mission planning. For mission planning Mission Support System (MSS) is used. Mission planning requires a lot of effort and experience to make a good plan. This can be facilitated if there are tools that can benefit from rules for actual or previously missions of the same character. Thera are two theses that have investigated these different aspects. The goal with this thesis is to partly demonstrate these methods in a prototype, alone and in combination, and partly try to answer the question if a combination of the methods is performing a better decision support than each of them alone. This thesis is based on two previously thesis. The method that is used to to be able to assess which method is preferable is to implement the both tools in a prototype. The prototype is then used to plan a few missions and applying the different methods alone and in combination and evaluate the result. The results indicate that from a planning point, a combination of the two methods should be used. However if one takes the time in consideration, then the case based method is not to recomend in its current status. This because the execution time is long. The execution time is up to 12 hours. Which does not work in reality.
162

Plánování cesty autonomního lokomočního robotu na základě strojového učení / Autonomous Locomotive Robot Path Planning on the Basis of Machine Learning

Krček, Petr January 2010 (has links)
As already clear from the title, this dissertation deals with autonomous locomotive robot path planning, based on machine learning. Robot path planning task is to find a path from initial to target position without collision with obstacles so that the cost of the path is minimized. Autonomous robot is such a machine which is able to perform tasks completely independently even in environments with dynamic changes. Path planning in dynamic partially known environment is a difficult problem. Autonomous robot ability to adapt its behavior to changes in the environment can be ensured by using machine learning methods. In the field of path planning the mostly used methods of machine learning are case based reasoning, neural networks, reinforcement learning, swarm intelligence and genetic algorithms. The first part of this thesis introduces the current state of research in the field of path planning. Overview of methods is focused on basic omnidirectional robots and robots with differential constraints. In the thesis, several methods of path planning for omnidirectional robot and robot with differential constraints are proposed. These methods are mainly based on case-based reasoning and genetic algorithms. All proposed methods were implemented in simulation applications. Results of experiments carried out in these applications are part of this work. For each experiment, the results are analyzed. The experiments show that the proposed methods are able to compete with commonly used methods, because they perform better in most cases.
163

Recherche d'information dirigée par les interfaces utilisateur : approche basée sur l'utilisation des ontologies de domaine / User interface-driven information retrieval : an ontology-based approach

Zidi, Amir 26 March 2015 (has links)
Ce mémoire porte sur l'utilisation des ontologies dans les systèmes de recherche d'information SRI dédiés à des domaines particuliers. Il se base sur une approche à deux niveaux, à savoir la formulation et la recommandation des requêtes. La formulation consiste à assister l'utilisateur dans l'expression de sa requête en se basant sur des concepts et des propriétés de l'ontologie de domaine utilisée. La recommandation consiste à proposer des résultats de recherche en utilisant la méthode du raisonnement à partir de cas. Dans cette méthode, une nouvelle requête est considérée comme un nouveau cas.La résolution de ce nouveau cas consiste à réutiliser les anciens cas similaires qui ne sont que des requêtes traitées auparavant. Afin de valider l'approche proposée, un système OntoCBRIR a été développé et un ensemble d'expérimentations a été élaboré. Enfin, les perspectives de recherche concluent le présent rapport. / This thesis study the using of ontologies in information retrieval systemdedicated to a specific domain. For that we propose a two-level approach to deal with i) the query formulation that assists the user in selecting concepts and properties of the used ontology ; ii) the query recommendation that uses the case-based reasoning method, where a new query is considered as a new case. Solving a new case consists of reusing similar cases from the history of the previous similar cases already processed. For the validation of the proposed approaches, a system was developed and a set of computational experimentations was made. Finally, research perspectives conclude that this present report.
164

Building a Cognitive Radio: From Architecture Definition to Prototype Implementation

Le, Bin 22 August 2007 (has links)
Cognitive radio (CR) technology introduces a revolutionary wireless communication mechanism in terminals and network segments, so that they are able to learn their environment and adapt intelligently to the most appropriate way of providing the service for the user's exact need. By supporting multi-band, mode-mode cognitive applications, the cognitive radio addresses an interactive way of managing the spectrum that harmonizes technology, market and regulation. This dissertation gives a complete story of building a cognitive radio. It goes through concept clarification, architecture definition, functional block building, system integration, and finally to the implementation of a fully-functional cognitive radio node prototype that can be directly packaged for application use. This dissertation starts with a comprehensive review of CR research from its origin to today. Several fundamental research issues are then addressed to let the reader know what makes CR a challenging and interesting research area. Then the CR system solution is introduced with the details of its hierarchical functional architecture called the Egg Model, modular software system called the cognitive engine, and the kernel machine learning mechanism called the cognition cycle. Next, this dissertation discusses the design of specific functional building blocks which incorporate environment awareness, solution making, and adaptation. These building blocks are designed to focus on the radio domain that mainly concerns the radio environment and the radio platform. Awareness of the radio environment is achieved by extracting the key environmental features and applying statistical pattern recognition methods including artificial neural networks and k-nearest neighbor clustering. Solutions for the radio behavior are made according to the recognized environment and the previous knowledge through case based reasoning, and further adapted or optimized through genetic algorithm solution search. New experiences are gained through the practice of the new solution, and thus the CR's knowledge evolves for future use; therefore, the CR's performance continues improving with this reinforcement learning approach. To deploy the solved solution in terms of the radio's parameters, a platform independent radio interface is designed. With this general radio interface, the algorithms in the cognitive engine software system can be applied to various radio hardware platforms. To support and verify designed cognitive algorithms and cognitive functionalities, a complete reconfigurable SDR platform, called the CWT2 waveform framework, is designed in this dissertation. In this waveform framework, a hierarchical configuration and control system is constructed to support flexible, real-time waveform reconfigurability. Integrating all the building blocks described above allows a complete CR node system. Based on this general CR node structure, a fully-functional Public Safety Cognitive Radio (PSCR) node is prototyped to provide the universal interoperability for public safety communications. Although the complete PSCR node software system has been packaged to an official release including installation guide and user/developer manuals, the process of building a cognitive radio from concept to a functional prototype is not the end of the CR research; on-going and future research issues are addressed in the last chapter of the dissertation. / Ph. D.
165

Similarity Determination and Case Retrieval in an Intelligent Decision Support System for Diabetes Management

Walker, Donald January 2007 (has links)
No description available.
166

Case Adaptation for an Intelligent Decision Support System for Diabetes Management

Cooper, Tessa L. January 2010 (has links)
No description available.
167

Lessons Learned from Designing a Comprehensive Case-Based Reasoning (CBR) Tool for Support of Complex Thinking

Richmond, Doug 25 May 2007 (has links)
This research study focused on learning lessons from the experience of designing a comprehensive case-based reasoning (CBR) tool for support of complex thinking skills. Theorists have historically identified, analyzed, and classified different thinking processes and skills. Thinking skills have been increasingly emphasized in national standards, state testing, curricula, teaching and learning resources, and research agendas. Complex thinking is the core of higher-order thinking. Complex thinking is engaged when different types of thinking and action converge to resolve a real-world, ill-structured issue such as solving a problem, designing an artifact, or making a decision. By integrating reasoning, memory, and learning in a model of cognition for learning from concrete problem-solving experience, CBR can be used to engage complex thinking. In similar and different ways, CBR theory and the related theories of constructivism and constructionism promote learning from concrete, ill-structured problem-solving experience. Seven factors or characteristics, and by extension, design requirements, that should be incorporated in a comprehensive CBR tool were extracted from theory. These requirements were consistent with five theory-, research-based facilitators of learning from concrete experience. Subsequent application of the Dick, Carey, and Carey model to these design requirements generated twenty-nine specifications for design of the tool. This research study was carried out using developmental research methodology and a standard development model. The design process included front-end analysis, creating a prototype of the tool, and evaluating the prototype. / Ph. D.
168

Statistical Experimental Design Framework for Cognitive Radio

Amanna, Ashwin Earl 30 April 2012 (has links)
This dissertation presents an empirical approach to identifying decisions for adapting cognitive radio parameters with no a priori knowledge of the environment. Cognitively inspired radios, attempt to combine observed metrics of system performance with artificial intelligence decision-making algorithms. Current architectures trend towards hybrid combinations of heuristics, such as genetic algorithms (GA) and experiential methods, such as case-based reasoning (CBR). A weakness in the GA is its reliance on limited mathematical models for estimating bit error rate, packet error rate, throughput, and signal-to-noise ratio. The CBR approach is similarly limited by its dependency on past experiences. Both methods have potential to suffer in environments not previously encountered. In contrast, the statistical methods identify performance estimation models based on exercising defined experimental designs. This represents an experiential decision-making process formed in the present rather than the past. There are three core contributions from this empirical framework: 1) it enables a new approach to decision making based on empirical estimation models of system performance, 2) it provides a systematic method for initializing cognitive engine configuration parameters, and 3) it facilitates deeper understanding of system behavior by quantifying parameter significance, and interaction effects. Ultimately, this understanding enables simplification of system models by identifying insignificant parameters. This dissertation defines an abstract framework that enables application of statistical approaches to cognitive radio systems regardless of its platform or application space. Specifically, it assesses factorial design of experiments and response surface methodology (RSM) to an over-the-air wireless radio link. Results are compared to a benchmark GA cognitive engine. The framework is then used for identifying software-defined radio initialization settings. Taguchi designs, a related statistical method, are implemented to identify initialization settings of a GA. / Ph. D.
169

Influence des facteurs émotionnels sur la résistance au changement dans les organisations

Menezes, Ilusca Lima Lopes de January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
170

Extraction et modélisation de connaissances : Application à la conception de procédés / Extraction and Modeling of Knowledge : Application in Process Design

Roldan Reyes, Eduardo 23 November 2012 (has links)
L'activité de conception est un processus complexe et décisif dans le cycle de vie des produits et des procédés de fabrication. Dans le contexte actuel, les chercheurs et ingénieurs de conception notent une nette augmentation de la complexité des produits et procédés, pour satisfaire au mieux l’ensemble des exigences croissantes provenant de l’ensemble des acteurs du cycle de vie (industriels et utilisateurs) mais aussi du monde normatif. La gestion des connaissances et de l’expertise métier est un atout important pour rendre plus efficace et accélérer ce processus. Les recherches actuelles sur la gestion des connaissances font émerger des méthodes et outils performants pour identifier, formaliser, exploiter et diffuser la connaissance et les expériences issues de conceptions passées en vue de produire rapidement de nouvelles solutions. Parmi les approches existantes le Raisonnement à Partir de Cas (RàPC) et la Programmation Par Contraintes (PPC) correspondent aux besoins identifiés en Génie des Procédés. A partir de l’analyse de ces deux approches, ce travail propose un couplage du RàPC et de la PPC afin de fournir un cadre méthodologique et un outil logiciel pour une aide à la conception. Le RàPC permet de capitaliser et de remémorer les expériences passées. Toutefois, la modification de la solution passée pour répondre aux exigences du nouveau problème nécessite l’ajout de nouvelles connaissances aussi appelées connaissances d’adaptation. La PPC, quant à elle, offre justement un cadre approprié pour modéliser et gérer la connaissance permettant l’obtention d’une solution à un problème mais aussi ces connaissances d’adaptation. Outre la formalisation des connaissances d’adaptation, une des difficultés réside dans l’acquisition de ces connaissances. Dans l’approche proposée, le cycle traditionnel du RàPC a été modifié de façon à créer une boucle d’interaction avec l’utilisateur. Lorsqu’un échec d’adaptation se produit, cette boucle est activée et l’expert est sollicité pour apporter les modifications nécessaires à l’obtention d’une solution appropriée. Cette correction est l’occasion d’acquérir en ligne cette nouvelle connaissance, qui sera par la suite mise à jour et ajoutée dans le système. Un cas d’étude sur la conception d’une opération unitaire de génie des procédés permet d’illustrer l’approche. / Design is a complex and crucial process within the lifecycle of products and production processes. In the current context, design engineers and researchers notice an increasing in complexity of products and processes, in order to meet all the requirements coming from all the participants(manufacturers and users alike) in the life cycle and in the normative world as well. Knowledge management is an important asset to accelerate this process and improve its efficiency. Current research on knowledge management is producing new methods and tools to identify, formalize, exploit and disseminate knowledge from past designs experiences to produce new solutions rapidly. Among existing approaches, Case-Based Reasoning (CBR) and Constraint Programming (CP) are suited to needs identified in Process Engineering. Based on the analysis of these two approaches, this work proposes a coupling of CBR and the CP to provide a methodological framework and a software tool to assist design. The CBR allows to capitalize and retrieve past experiences. However, transforming the past solution to fit the new problem requirements needs the addition of new knowledge also known as Adaptation Knowledge. CP, meanwhile, offers an appropriate framework to model and manage knowledge required to obtain an appropriate solution to a problem, but also the adaptation knowledge. In addition to the formalization of adaptation knowledge, one of the remaining major difficulties lies in knowledge acquisition. In the proposed approach, the traditional CBR cycle has been modified to create a user interaction loop. When an adaptation failure occurs, this loop is activated and the expert is asked to make the necessary changes to achieve an appropriate solution. This correction is an opportunity to acquire this new knowledge online, which will be subsequently updated and added into the system. A case study on the design of a unit operation of Process Engineering is used to illustrate the approach

Page generated in 0.0304 seconds