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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.
71

CBR-DFMA: A Case-Based System Used to Assembly Part Design in the Early Design Stage

Chang, Guanghsu, Su, Cheng Chung, Priest, John W. 01 January 2006 (has links)
Many conflicting issues exist between product design and manufacturing department. In the early design stage, designers often do not have enough expertise to successfully address all these issues. This results in a product design with a low level of assemblability and manufacturability. Hence, an intelligent decision support system is needed for early design stages to improve a design. This paper proposed a web-based intelligent decision support system, CBR-DFMA, connecting with a case base, database and knowledge base. Early experimental results indicate that potential design problems can be detected in advance, design expertise can be effectively disseminated and effective training is offered to designer by employing this system.
72

CASE BASED REASONING – TAYLOR SERIES MODEL TO PREDICT CORROSION RATE IN OIL AND GAS WELLS AND PIPELINES

Khajotia, Burzin K. 17 April 2007 (has links)
No description available.
73

A RADIOTHERAPY PLAN SELECTOR USING CASE-BASED REASONING

Zziwa, Aloysious January 2010 (has links)
Developing a head and neck cancer treatment plan for a candidate of Intensity Modulated Radiation Therapy (IMRT) requires extensive domain knowledge and subjective experience. Therefore, it takes a cancer treatment team at least 2 to 3 days to develop such a plan from scratch. Many times the team may not use a reference plan. Sometimes, to reduce the amount of time taken to generate each treatment plan, these experts recall a patient, whose plan they recently prepared, and who had similar symptoms as the candidate. Using this recalled patient's plan as the starting point, the cancer treatment team modifies it based on the differences in the symptoms of the new candidate and those of the reference patient record. The resultant plan after modification is presented as the new treatment plan for the oncologist to evaluate its suitability for treatment of the candidate. This approach is heavily dependent on the team's choice of the reference patient record. Choosing a starting treatment plan where the patient's symptoms are not the closest to the new candidate implies that more time will be spent modifying the plan than is necessary and the resultant treatment plan may not be the best achievable under the same circumstances given a better starting plan. Therefore, the team's bias in choosing the starting plan may affect the quality of treatment plan that is finally produced for the candidate. This thesis proposes a system that behaves like an un-biased radiotherapy expert - following a similar process and standards as the human experts and which searches the entire IMRT patient database and returns the record (with patient symptoms and treatment plan) for a patient whose symptoms are most similar to the candidate's symptoms. It takes in the new candidate's information (from diagnosis, scans of the tumor and interviews with the candidate), searches the database and prints out a patient record showing another patient's treatment plan as the suggested starting point for generating the new plan. The system uses Case-Based Reasoning (CBR) because it mimics the experts' approach since it makes use of previous successes and shuns reasoning that has failed in the past. This occurs by considering only treatment plans that have been implemented successfully on patients in the hospital archive. For this thesis, CBR is applied using fuzzy IF-THEN rules to search the patient database. Fuzzy logic is used because it can handle imprecise expressions commonly used in natural language to determine the appropriate weight of the patient attributes in the search process. Filtering of patient records based on parameter value ranges is also used to reduce the number of records that have to be compared. The system code developed for this thesis was prepared in Java and C Language Integrated Production System (CLIPS) using the Java Expert System Shell (JESS). This system is part of a bigger expert system that is being prepared by the Intelligent Systems Applications Center (ISAC) for Thomas Jefferson University Hospital, expected to generate a radiotherapy plan for a patient designated for IMRT treatment. Initial results from the developed prototype prove the viability of selecting similar patients using CBR. It is important to note that the overall objective of the project is to build a system that effectively aids decision support by the IMRT team when generating a new treatment plan and not to replace them. The team is expected to use the generated plan as a starting point in determining a new treatment plan. If the generated plan is sufficient, the oncologist and their team will have to check this plan (in their various capacities) against expected standards for quality control before passing it on for implementation. This will save them time in planning and allow them to focus more on the patient's needs hence a higher quality of life for the patient after treatment. / Electrical and Computer Engineering
74

Contribution à un système de retour d'expérience basé sur le raisonnement à partir de cas conversationnel : application à la gestion des pannes de machines industrielles / Contribution to an experience feedback system based on conversational case-based reasoning : application in management of failure diagnostic procedures for industrial machines

Armaghan, Negar 28 May 2009 (has links)
Face à l’évolution technologique rapide des produits, l’innovation incrémentale des nouveaux produits, et la mobilité du personnel le plus expérimenté, les entreprises cherchent à formaliser et à capitaliser leurs expériences et les savoir-faire des acteurs d’entreprise en vue d’une réutilisation ultérieure. Afin de répondre à cette problématique, l’approche du raisonnement à partir de cas conversationnel (RàPCC) est une réponse potentielle à la question de la capitalisation et de la réutilisation des connaissances. Notre recherche s’intéresse aux méthodes permettant de piloter le retour d’expérience (RETEX) appliqué à la résolution de problèmes techniques. Notre méthodologie pour créer un système d’aide au diagnostic des pannes est divisée en quatre phases : la description d’événements, l’élaboration de l’ensemble des solutions apportées aux pannes, la mise en place d’une aide au diagnostic grâce aux arbres de défaillances et la mise en place d’un système informatique. Afin d’extraire les connaissances tacites et les formaliser, nous avons créé des protocoles de décision dans le but d’aider l’expert à résoudre un problème industriel. Nous avons donc proposé une formulation et l’élaboration de cas conversationnels dans le domaine du diagnostic. Ces cas doivent être stockés dans une base de cas. Afin de valider notre proposition méthodologique, nous avons réalisé la phase expérimentale dans une entreprise industrielle de l’Est de la France. Nous proposons finalement une maquette informatique conçue pour l’entreprise. Cette maquette permet de réaliser un diagnostic des pannes en créant des cas dans une base de cas pour une réutilisation ultérieure / Faced with the fast technological development of products, incremental innovation of new products, and the mobility of their most experienced staff, companies are seeking to formalize and capitalize on the experiences and know-how of their personnel in order to reuse them later. To deal with these problems, the conversational case based reasoning (CCBR) approach is a potential answer to the question of capitalization and reuse of knowledge. Our research focuses on methods to manage experience feedback (EF). We are placed in the field of experience feedback applied to technical problem solving. Our methodology for creating aided failure diagnosis systems is divided into four phases: the events description, the development of all solutions to failures, the arrangement of a diagnostic aid through fault trees and setting up a computer system. We based our work on the fault tree approach in order to extract tacit knowledge and its formalization. Our objective was to create decision protocols in order to assist the expert in solving an industrial problem. Therefore, we have proposed a formulation and development of conversational cases in diagnosis. These cases must be memorised in a database of cases. To validate our proposal methodology, we have carried out the experimental phase in an industrial company in eastern France. This experiment allowed us to validate our work and highlight its advantages and limitations. Finally, we propose a computer model designed for the company. This model enables failure diagnosis by creating the case in a case base for later utilization
75

Exploring the Development and Transfer of Case Use Skills in Middle-School Project-Based Inquiry Classrooms

Owensby, Jakita Nicole 11 April 2006 (has links)
The ability to interpret and apply experiences, or cases (Kolodner, 1993; 1997) is a skill (Anderson, et. al, 1981; Anderson, 2000) that is key to successful learning that can be transferred (Bransford, Brown and Cocking, 1999) to new learning situations. For middle-schoolers in a project-based inquiry science classroom, interpreting and applying the experiences of experts to inform their design solutions is not always easy (Owensby and Kolodner, 2002). Interpreting and applying an expert case and then assessing the solution that results from that application are the components of a process I call case use. This work seeks to answer three questions: 1. How do small-group case use capabilities develop over time? 2. How well are students able to apply case use skills in new situations over time? 3. What difficulties do learners have as they learn case use skills and as they apply case use skills in new situations? What do these difficulties suggest about how software might further support cognitive skill development using a cognitive apprenticeship (Collins, Brown and Newman, 1989) framework? I argue that if learners in project based inquiry classrooms are able to understand, engage in, and carry out the processes involved in interpreting and applying expert cases effectively, then they will be able to do several things. They will learn those process and be able to read an expert case for understanding, glean the lessons they can learn from it, and apply those lessons to their question or challenge. Furthermore, I argue that they may also be able to transfer interpretation, application, and assessment skills to other learning situations where application of cases is appropriate.
76

A combined case-based reasoning and process execution approach for knowledge-intensive work

Martin, Andreas 11 1900 (has links)
Knowledge and knowledge work are key factors of today’s successful companies. This study devises an approach for increasing the performance of knowledge work by shifting it towards a process orientation. Business process management and workflow management are methods for structured and predefined work but are not flexible enough to support knowledge work in a comprehensive way. Case-based reasoning (CBR) uses the knowledge of previously experienced cases in order to propose a solution to a problem. CBR can be used to retrieve, reuse, revise, retain and store functional and process knowledge. The aim of the research was to develop an approach that combines CBR and process execution to improve knowledge work. The research goals are: a casedescription for knowledge work that can be integrated into a process execution system and that contains both functional and process knowledge; a similarity algorithm for the retrieval of functional and procedural knowledge; and an adaptation mechanism that deals with the different granularities of solution parts. This thesis contains a profound literature framework and follows a design science research (DSR) strategy. During the awareness phase of the design science research process, an application scenario was acquired using the case study research method, which is the admission process for a study programme at a university. This application scenario is used to introduce and showcase the combined CBR and process execution approach called ICEBERG-PE, which consists of a case model and CBR services. The approach is implemented as a prototype and can be instantiated using the ICEBERG-PE procedure model, a specific procedure model for ontology-based, CBR projects. The ICEBERG-PE prototype has been evaluated using triangulated evaluation data and different evaluation settings to confirm that the approach is transferable to other contexts. Finally, this thesis concludes with potential recommendations for future research. / Computing / D. Phil. (Information Systems)
77

(Meta)Knowledge modeling for inventive design / Modélisation des (méta)connaissances pour la conception inventive

Yan, Wei 07 February 2014 (has links)
Un nombre croissant d’industries ressentent le besoin de formaliser leurs processus d’innovation. Dans ce contexte, les outils du domaine de la qualité et les approches d’aide à la créativité provenant du "brain storming" ont déjà montré leurs limites. Afin de répondre à ces besoins, la TRIZ (Acronyme russe pour Théorie de Résolution des Problèmes Inventifs), développée par l’ingénieur russe G. S. Altshuller au milieu du 20ème siècle, propose une méthode systématique de résolution de problèmes inventifs multidomaines. Selon TRIZ, la résolution de problèmes inventifs consiste en la construction du modèle et l’utilisation des sources de connaissance de la TRIZ. Plusieurs modèles et sources de connaissances permettent la résolution de problèmes inventifs de types différents, comme les quarante Principes Inventifs pour l’élimination des contradictions techniques. Toutes ces sources se situent à des niveaux d’abstractions relativement élevés et sont, donc, indépendantes d’un domaine particulier, qui nécessitent des connaissances approfondies des domaines d’ingénierie différents. Afin de faciliter le processus de résolution de problèmes inventifs, un "Système Intelligent de Gestion de Connaissances" est développé dans cette thèse. D’une part, en intégrant les ontologies des bases de connaissance de la TRIZ, le gestionnaire propose aux utilisateurs de sources de connaissance pertinentes pour le modèle qu’ils construisent, et d’autre part, le gestionnaire a la capacité de remplir "automatiquement" les modèles associés aux autres bases de connaissance. Ces travaux de recherche visent à faciliter et automatiser le processus de résolution de problèmes inventifs. Ils sont basés sur le calcul de similarité sémantique et font usage de différentes technologies provenantes de domaine de l’Ingénierie de Connaissances (modélisation et raisonnement basés sur les ontologies, notamment). Tout d’abord, des méthodes de calcul de similarité sémantique sont proposées pour rechercher et définir les liens manquants entre les bases de connaissance de la TRIZ. Ensuite, les sources de connaissance de la TRIZ sont formalisées comme des ontologies afin de pouvoir utiliser des mécanismes d’inférence heuristique pour la recherche de solutions spécifiques. Pour résoudre des problèmes inventifs, les utilisateurs de la TRIZ choisissent dans un premier temps une base de connaissance et obtiennent une solution abstraite. Ensuite, les éléments des autres bases de connaissance similaires aux éléments sélectionnés dans la première base sont proposés sur la base de la similarité sémantique préalablement calculée. A l’aide de ces éléments et des effets physiques heuristiques, d’autres solutions conceptuelles sont obtenues par inférence sur les ontologies. Enfin, un prototype logiciel est développé. Il est basé sur cette similarité sémantique et les ontologies interviennent en support du processus de génération automatique de solutions conceptuelles. / An increasing number of industries feel the need to formalize their innovation processes. In this context, quality domain tools show their limits as well as the creativity assistance approaches derived from brainstorming. TRIZ (Theory of Inventive Problem Solving) appears to be a pertinent answer to these needs. Developed in the middle of the 20th century by G. S. Althshuller, this methodology's goal was initially to improve and facilitate the resolution of technological problems. According to TRIZ, the resolution of inventive problems consists of the construction of models and the use of the corresponding knowledge sources. Different models and knowledge sources were established in order to solve different types of inventive problems, such as the forty inventive principles for eliminating the technical contradictions. These knowledge sources with different levels of abstraction are all built independent of the specific application field, and require extensive knowledge about different engineering domains. In order to facilitate the inventive problem solving process, the development of an "intelligent knowledge manager" is explored in this thesis. On the one hand, according to the TRIZ knowledge sources ontologies, the manager offers to the users the relevant knowledge sources associated to the model they are building. On the other hand, the manager has the ability to fill "automatically" the models of the other knowledge sources. These research works aim at facilitating and automating the process of solving inventive problems based on semantic similarity and ontology techniques. At first, the TRIZ knowledge sources are formalized based on ontologies, such that heuristic inference can be executed to search for specific solutions. Then, methods for calculating semantic similarity are explored to search and define the missing links among the TRIZ knowledge sources. In order to solve inventive problems, the TRIZ user firstly chooses a TRIZ knowledge source to work for an abstract solution. Then, the items of other knowledge sources, which are similar with the selected items of the first knowledge source, are obtained based on semantic similarity calculated in advance. With the help of these similar items and the heuristic physical effects, other specific solutions are returned through ontology inference. Finally, a software prototype is developed based on semantic similarity and ontology inference to support this automatic process of solving inventive problems.
78

The Study of Project-Based Learning in Preservice Teachers

Anderson, Ashley Ann January 2016 (has links)
Project-based learning (PBL) is a teaching approach where students engage in the investigation of real-world problems through their inquiries. Studies found considerable support for PBL on student performance and improvement in grades K-12 and at the collegiate level. However, fewer studies have examined the effects of PBL at the collegiate level in comparison to K-12 education. No studies have examined the effects of PBL with preservice teachers taking educational psychology courses. The purpose of this study was to provide an analysis of PBL with preservice teachers taking educational psychology courses. An experiment was conducted throughout two semesters to evaluate student achievement and satisfaction in an undergraduate educational psychology child development course and in an undergraduate educational psychology assessments course, which included the same students from the first semester. Student achievement was determined using quantitative and qualitative analyses in each semester and longitudinally. Results in semester one indicated that the comparison group outperformed the PBL group. Results in semester two suggested there were no differences in instructional styles between groups. Longitudinal analyses showed that the comparison group declined in performance over time, whereas the PBL group improved over time; although, the comparison group still outperformed the PBL group. Results of this study indicate that PBL was not an influential teaching method for preservice teachers taking educational psychology courses.
79

A case-based reasoning methodology to formulating polyurethanes

Segura-Velandia, Diana M. January 2006 (has links)
Formulation of polyurethanes is a complex problem poorly understood as it has developed more as an art rather than a science. Only a few experts have mastered polyurethane (PU) formulation after years of experience and the major raw material manufacturers largely hold such expertise. Understanding of PU formulation is at present insufficient to be developed from first principles. The first principle approach requires time and a detailed understanding of the underlying principles that govern the formulation process (e.g. PU chemistry, kinetics) and a number of measurements of process conditions. Even in the simplest formulations, there are more that 20 variables often interacting with each other in very intricate ways. In this doctoral thesis the use of the Case-Based Reasoning and Artificial Neural Network paradigm is proposed to enable support for PUs formulation tasks by providing a framework for the collection, structure, and representation of real formulating knowledge. The framework is also aimed at facilitating the sharing and deployment of solutions in a consistent and referable way, when appropriate, for future problem solving. Two basic problems in the development of a Case-Based Reasoning tool that uses past flexible PU foam formulation recipes or cases to solve new problems were studied. A PU case was divided into a problem description (i. e. PU measured mechanical properties) and a solution description (i. e. the ingredients and their quantities to produce a PU). The problems investigated are related to the retrieval of former PU cases that are similar to a new problem description, and the adaptation of the retrieved case to meet the problem constraints. For retrieval, an alternative similarity measure based on the moment's description of a case when it is represented as a two dimensional image was studied. The retrieval using geometric, central and Legendre moments was also studied and compared with a standard nearest neighbour algorithm using nine different distance functions (e.g. Euclidean, Canberra, City Block, among others). It was concluded that when cases were represented as 2D images and matching is performed by using moment functions in a similar fashion to the approaches studied in image analysis in pattern recognition, low order geometric and Legendre moments and central moments of any order retrieve the same case as the Euclidean distance does when used in a nearest neighbour algorithm. This means that the Euclidean distance acts a low moment function that represents gross level case features. Higher order (moment's order>3) geometric and Legendre moments while enabling finer details about an image to be represented had no standard distance function counterpart. For the adaptation of retrieved cases, a feed-forward back-propagation artificial neural network was proposed to reduce the adaptation knowledge acquisition effort that has prevented building complete CBR systems and to generate a mapping between change in mechanical properties and formulation ingredients. The proposed network was trained with the differences between problem descriptions (i.e. mechanical properties of a pair of foams) as input patterns and the differences between solution descriptions (i.e. formulation ingredients) as the output patterns. A complete data set was used based on 34 initial formulations and a 16950 epochs trained network with 1102 training exemplars, produced from the case differences, gave only 4% error. However, further work with a data set consisting of a training set and a small validation set failed to generalise returning a high percentage of errors. Further tests on different training/test splits of the data also failed to generalise. The conclusion reached is that the data as such has insufficient common structure to form any general conclusions. Other evidence to suggest that the data does not contain generalisable structure includes the large number of hidden nodes necessary to achieve convergence on the complete data set.
80

Improved regulatory oversight using real-time data monitoring technologies in the wake of Macondo

Carter, Kyle Michael 10 October 2014 (has links)
As shown by the Macondo blowout, a deepwater well control event can result in loss of life, harm to the environment, and significant damage to company and industry reputation. Consistent adherence to safety regulations is a recurring issue in deepwater well construction. The two federal entities responsible for offshore U.S. safety regulation are the Department of the Interior’s Bureau of Safety and Environmental Enforcement (BSEE) and the U.S. Coast Guard (USCG), with regulatory authorities that span well planning, drilling, completions, emergency evacuation, environmental response, etc. With such a wide range of rules these agencies are responsible for, safety compliance cannot be comprehensively verified with the current infrequency of on-site inspections. Offshore regulation and operational safety could be greatly improved through continuous remote real-time data monitoring. Many government agencies have adopted monitoring regimes dependent on real-time data for improved oversight (e.g. NASA Mission Control, USGS Earthquake Early Warning System, USCG Vessel Traffic Services, etc.). Appropriately, real-time data monitoring was either re-developed or introduced in the wake of catastrophic events within those sectors (e.g. Challenger, tsunamis, Exxon Valdez, etc.). Over recent decades, oil and gas operators have developed Real-Time Operations Centers (RTOCs) for continuous, pro-active operations oversight and remote interaction with on-site personnel. Commonly seen as collaborative hubs, RTOCs provide a central conduit for shared knowledge, experience, and improved decision-making, thus optimizing performance, reducing operational risk, and improving safety. In particular, RTOCs have been useful in identifying and mitigating potential well construction incidents that could have resulted in significant non-productive time and trouble cost. In this thesis, a comprehensive set of recommendations is made to BSEE and USCG to expand and improve their regulatory oversight activities through remote real-time data monitoring and application of emerging real-time technologies that aid in data acquisition and performance optimization for improved safety. Data sets and tools necessary for regulators to effectively monitor and regulate deepwater operations (Gulf of Mexico, Arctic, etc.) on a continuous basis are identified. Data from actual GOM field cases are used to support the recommendations. In addition, the case is made for the regulator to build a collaborative foundation with deepwater operators, academia and other stakeholders, through the employment of state-of-the-art knowledge management tools and techniques. This will allow the regulator to do “more with less”, in order to address the fast pace of activity expansion and technology adoption in deepwater well construction, while maximizing corporate knowledge and retention. Knowledge management provides a connection that can foster a truly collaborative relationship between regulators, industry, and non-governmental organizations with a common goal of safety assurance and without confusing lines of authority or responsibility. This solves several key issues for regulators with respect to having access to experience and technical know-how, by leveraging industry experts who would not normally have been inaccessible. On implementation of the proposed real-time and knowledge management technologies and workflows, a phased approach is advocated to be carried out under the auspices of the Center for Offshore Safety (COS) and/or the Offshore Energy Safety Institute (OESI). Academia can play an important role, particularly in early phases of the program, as a neutral playing ground where tools, techniques and workflows can be tried and tested before wider adoption takes place. / text

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