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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

The use of system development methodologies in the development of decision support systems : An interpretive study / J.P.S. Ellis

Ellis, Jacobus Philippus Swart January 2010 (has links)
The world we live in today demands systems that make our lives easier and help us make the right choices on time. There exists a growing need for quality products that help us in our day to day activities. Easy-to-use computer-based decision support systems apply all available and applicable data with the correct model, knowledge and skill of decision makers to support the user to choose the best solution. It is therefore important to develop decision support systems correctly to be of value to the user. Looking at other information system developments, the author tries to suggest ways to develop decision support systems. System development methodologies are investigated to determine if they are able to address the development of the very important decision support system components. Five methodologies were discussed and researched for their theoretical suitability to address the development of decision support systems. The author performed qualitative research using case studies and semi-structured interviews to assess the use or non-use of system development methodologies in the development of decision support systems in a South African context. Content and cross-case analyses were used to achieve results that are discussed to broaden the knowledge on the development of decision support systems. The author provides some explanations to why system development methodologies were not used in the development of the case studies. This research not only contributes to the academic body of knowledge about using system development methodologies in the development of decision support systems, but could also be useful to developers embarking on a new decision support system development. / Thesis (MSc (Computer Science))--North-West University, Potchefstroom Campus, 2011.
72

Selecting Sustainable Point-of-Use and Point-of-Entry Drinking Water Treatment: A Decision Support System

Hamouda, Mohamed January 2011 (has links)
Point-of-use (POU) and point-of-entry (POE) water treatment are forms of decentralized water treatment that are becoming increasingly sought alternatives for ensuring the safety of drinking water. Although the acceptance of POU and POE systems is still the subject of some debate, it is generally acknowledged that they have a role to play in drinking water treatment. However, some of the main drivers for the increase in the use of POU and POE alternatives include: (1) the emergence of new technologies with high removal efficiencies of target contaminants; (2) the enhanced certification system of POU and POE treatment devices and components which ensures that devices have been well engineered to achieve defined contaminant removal targets and do not add contaminants from materials of construction; (3) the inclusion of POU and POE systems as acceptable means to comply with drinking water standards; and (4) the concerns voiced by consumers in several surveys regarding the safety of centrally treated drinking water; which, regardless of whether or not these concerns are justified, have led to an increase in the use of POU and POE treatment systems. With the commercialization of these devices the task of selecting a suitable device for treatment has become cumbersome. When the inherent complexity of a particular drinking water treatment task is added to the mix, a complex decision making situation is created. Thus the need for designing a decision support tool to compare and select POU and POE treatment systems was evident. Currently the best decision aid for selecting POU and POE systems is NSF International’s listing of the devices and their contaminant reduction claims. A significant contribution of this research is the depiction of an appropriate conceptual framework for developing usable and valid decision support systems (DSSs) to select or design water or wastewater treatment systems. A thorough investigation of the methods used to develop DSSs benchmarked a systematic approach to developing DSSs, which includes the analysis of the treatment problem(s), knowledge acquisition and representation, and the identification and evaluation of criteria controlling the selection of optimal treatment systems. Finally, it was concluded that there is a need to develop integrated DSSs that are generic, user-friendly and employ a systems analysis approach. Another significant contribution of this research is applying a systems analysis approach to outline aspects of implementation, management, and governance of POU and POE water treatment systems. The analysis also included a timeline of the progress of POU and POE treatment from regulatory, industry and certification, and research perspectives. Results of the analysis were considered the first step of a conceptual framework for the sustainability assessment of POU and POE treatment systems which acts as the basis for developing a decision support system that will help select sustainable POU or POE treatment systems. In the context of POU and POE treatment, sustainability encompasses providing: (a) safe drinking water to help maintain good human health and hygiene; (b) minimum negative impact on the environment; (c) better use of human, natural, and financial resources; (d) a high degree of functional robustness and flexibility; and (e) cultural acceptance thus encouraging responsible behavior by the users. The most significant contribution of this research is developing, for the first time, a set of sustainability criteria, objectives, and quantifiable indicators to properly assess the sustainability of the various POU and POE alternatives. Twenty five quantitative and qualitative indicators covering technical, economic, environmental, and socio-cultural aspects of implementing a POU or a POE system were defined. Results of a survey of experts’ judgment on the effectiveness of the developed list of indicators generated 52 comments from 11 experts, which helped in refining and enhancing the list. The conceptual framework for assessing the sustainability of POU and POE systems represented a blueprint for building the decision support system. Decision logic and cognitive thinking was used to formulate the calculation of the 20 refined indicators. The Analytical Hierarchy Process (AHP), a recognized Multi-criteria Decision Analysis (MCDA) tool, was employed to construct the structural hierarchy of sustainability indicators. Pairwise comparison was used to help in the analysis of indicators' relative importance and develop the indicators’ weights. A survey was designed to develop the relative weights of the indicators based on the average response of 19 stakeholders to a series of pairwise comparison questions pertaining to the relative importance of the indicators. Finally, the practical contribution of this research is the development of, for the first time, a new Decision Support System for Selecting Sustainable POU and POE Treatment Systems (D4SPOUTS) suitable for a particular water treatment case. The MCDA technique explained above is combined with designed screening rules, constraints, and case characteristics to be applied to a knowledgebase of POU and POE treatment systems incorporated in the DSS. The components of the DSS were built using Microsoft® Excel® and Visual Basic® for Applications. The quality of the DSS and aspects of its usability, applicability, and sensitivity analysis are demonstrated through a hypothetical case study for lead removal from drinking water. This research is expected to assist water purveyors, consultants, and other stakeholders in selecting sustainable and cost effective POU and POE treatment systems.
73

ONTOLOGY MERGING USING SEMANTICALLY-DEFINED MERGE CRITERIA AND OWL REASONING SERVICES: TOWARDS EXECUTION-TIME MERGING OF MULTIPLE CLINICAL WORKFLOWS TO HANDLE COMORBIDITIES

borna, jafarpour 16 December 2013 (has links)
Semantic web based decision support systems represent domain knowledge using ontologies that capture the domain concepts, their relationships and instances. Typically, decision support systems use a single knowledge model—i.e. a single ontology—which at times restricts the knowledge coverage to only select aspects of the domain knowledge. The integration of multiple knowledge models—i.e. multiple ontologies—provides a holistic knowledge model that encompasses multiple perspectives, orientations and instances. The challenge is the execution-time merging of multiple ontologies whilst maintaining knowledge consistency and procedural validity. Knowledge morphing aims at the intelligent merging of multiple computerized knowledge artifacts—represented as distinct ontological models—in order to create a holistic and networked knowledge model. In our research, we have investigated and developed a knowledge morphing framework—termed as OntoMorph—that supports ontology merging through: (1) Ontology Reconciliation whereby we harmonize multiple ontologies in terms of their vocabularies, knowledge coverage, and description granularities; (2) Ontology Merging where multiple reconciled ontologies are merged into a single merged ontology. To achieve ontology merging, we have formalized a set of semantically-defined merging criteria that determine ontology merge points, and describe the associated process-specific and knowledge consistency constraints that need to be satisfied to ensure consistent ontology merging; and (3) Ontology Execution whereby we have developed logic-based execution engines for both execution-time ontology merging and the execution of the merged ontology to infer knowledge-based recommendations. We have utilized OWL reasoning services, for efficient and decidable reasoning, to execute an OWL ontology. We have applied the OntoMorph framework for clinical decision support, more specifically to achieve the dynamic merging of multiple clinical practice guidelines in order to handle comorbid situations where a patient may have multiple diseases and hence multiple clinical guidelines are to be simultaneously operationalized. We have demonstrated the execution time merging of ontologically-modelled clinical guidelines, such that the decision support recommendations are derived from multiple, yet merged, clinical guidelines such that the inferred recommendations are clinically consistent. The thesis contributes new methods for ontology reconciliation, merging and execution, and presents a solution for execution-time merging of multiple clinical guidelines.
74

Case Based Decision Support System Forbid Markup Estimation Of International Construction Projects At The Tender Stage

Gur, Ahmet K 01 December 2005 (has links) (PDF)
Subsequent to preparation of a valid base estimate for a construction project tender, it is required to add a bid markup on top of the base estimate. While an exaggerated bid markup weakens the competitiveness of the contractor, an underestimated one makes the contractor susceptible to financial losses. Therefore, an effective and reliable bid markup estimation method is indispensable to the success of a contractor both at the tender and the performance stages. The prevalent practice among contractors is to identify a certain percentage to add on the base estimate relying on their judgment without substantial ex! plicit support. In this thesis, a case based decision support system, which will count on the experience of the top experts of Turkish international contractors, will be constructed. Meanwhile, factors which are essential to bid markup estimation are to be identified.
75

An agent-based location evaluation model

Sirikijpanichkul, Ackchai January 2008 (has links)
Truck transportation is considered as a favourable mode by shippers to carry freight at most ranges of distance as it has more flexibility in fleet size, capacity, scheduling, routing, and access. Although truck is considered as the popular mode for freight transportation, road-rail intermodal freight transportation becomes an attractive alternative to road only mode since the latter has no longer assured a reliable service due to traffic congestion problem. It also raises public concern in environmental and road safety impacts. Intermodal freight transportation is defined as a system that carries freight from origin to destination using two or more transportation modes where transfers between modes occur at an intermodal freight terminal. Success of the terminal depends on four major factors, namely: location, efficiency, financial sustainability, and rail level of service. Among these, the location is one of the most crucial success factors and needs to be considered carefully as it has direct and indirect impacts on a number of stakeholders including terminal users, terminal operators, transport network infrastructure providers, and community. Limitations of previous terminal location evaluation models in representing individual preference and behaviour as well as accommodating negotiation and communication between the players bring in an opportunity to develop a new model which is more flexible and capable of providing a solution that is not necessary to be optimal, but acceptable for every player without requiring explicit trade-offs. This thesis is aimed at demonstrating the feasibility of applying an agent-based approach to the evaluation of intermodal freight terminal location and investigating terminal effectiveness against stakeholder equity and some important aspects arising from the different stakeholders’ viewpoints. Agent technologies were introduced to model the stakeholders as individual agents. The agent concept was adopted to develop a decentralised location evaluation system that is able to balance the terminal effectiveness with the stakeholder equity. The proposed agent-based location evaluation model was modelled as a hierarchical control system that comprises three decision levels: local level, stakeholder level and policy level. Policy level is the highest decision level, which is represented by a policy maker. Apart from the policy level, the rest can be viewed as operational decision levels. Local level is the lowest control level. At this level, each stakeholder was classified into stakeholder groups based on their characteristics and interest. The terminal scenarios were then evaluated based on benefit maximisation criteria. Stakeholder control is the higher control level than the local level. It represents the control level where negotiations and decisions between groups of people (stakeholders) with different point of views are made. At this level, negotiation process was used to determine terminal location based on preference and equity of stakeholders. The determined terminal site was then used in the evaluation against constraints to ensure that all agents are satisfied. The terminal location decision for South East Queensland (SEQ) was applied as a case study of this thesis. The SEQ strategic freight transport model was developed, calibrated, and validated to assist in providing inputs for the evaluation of terminal location. The results indicated that for the developed agent-based location evaluation model, Yatala was selected as the most appropriate terminal location that results in the highest effectiveness and equity (as measured by level of satisfaction and Gini coefficient, respectively). Other location evaluation models were also used in comparison with the developed agent-based location evaluation model. Those include P-Median, P-Centre, and maximum covering models. It was found that the agent-based location evaluation model outperformed the other location evaluation models. Finally, a sensitivity analysis was conducted in order to evaluate the consistency of model outputs against the uncertainties in the input parameters. In most cases, the terminal location decisions obtained from the developed agent-based location evaluation model was not sensitive to the changes in those parameters. However, the results suggested that when a unit cost of truck travel delay increased, the impact on the final terminal location decisions was observed. This thesis demonstrated the feasibility of applying a decentralised approach to terminal location decision problem using a multi-agent concept and evaluating it against other well-known location problems. A new framework and methodology for the planning of intermodal terminal location evaluation was also formulated. Finally, the problems of terminal location evaluation and optimisation of intermodal freight terminal operation were integrated into a single evaluation model.
76

Study on application possibilities of Case-Based Reasoning on the domain of scheduling problems / Etude de l'application du raisonnement à partir de cas pour des problèmes d'ordonnancement

Kocsis, Tibor 12 December 2011 (has links)
Ces travaux concernent la mise en place d'un système d'aide à la décision, s'appuyant sur le raisonnement à partir de cas, pour la modélisation et la résolution des problèmes d'ordonnancement en génie des procédés. Une analyse de co-citation a été exécutée afin d'extraire de la littérature la connaissance nécessaire à la construction de la stratégie d'aide à la décision et d'obtenir une image de la situation, de l'évolution et de l'intensité de la recherche du domaine des problèmes d'ordonnancement. Un système de classification a été proposée, et la nomenclature proposée par Blazewicz et al. (2007) a été étendue de manière à pouvoir caractériser de manière complète les problèmes d'ordonnancement et leur mode de résolution. Les difficultés d'adaptation du modèle ont été discutées, et l'efficacité des quatre modèles de littérature a été comparée sur trois exemples de flow-shop. Une stratégie de résolution est proposée en fonction des caractéristiques du problème mathématique. / The purpose of this study is to work out the foundations of a decision-support system in order to advise efficient resolution strategies for scheduling problems in process engineering. This decision-support system is based on Case-Based Reasoning. A bibliographic study based on co-citation analysis has been performed in order to extract knowledge from the literature and obtain a landscape about scheduling research, its intensity and evolution. An open classification scheme has been proposed to scheduling problems, mathematical models and solving methods. A notation scheme corresponding to the classification has been elaborated based on the nomenclature proposed by Blazewicz et al. (2007). The difficulties arising during the adaptation of a mathematical model to different problems is discussed, and the performances of four literature mathematical models have been compared on three flow-shop examples. A resolution strategy is proposed based on the characteristics of the scheduling problem.
77

Simulação da produção de madeira serrada

Heinrich, Daniele January 2010 (has links)
O aumento da competição e a aceleração dos avanços tecnológicos têm contribuído para o desenvolvimento de novos conceitos e estratégias de produção, direcionando as empresas à busca contínua de novas oportunidades de negócios e melhorias dos processos produtivos. A indústria de madeira serrada no Brasil, na sua grande maioria, apresenta estrutura produtiva precária, com baixa produtividade, e sua sobrevivência depende da busca por melhorias de eficiência técnica e econômica dos processos de transformação. Nesta busca de melhorias de processos, a simulação de sistemas pode ser utilizada como ferramenta de apoio à decisão no planejamento da produção de serrarias, contribuindo para a competitividade das empresas. Esta dissertação objetiva desenvolver um modelo de simulação da produção de madeira serrada para auxiliar no planejamento da produção de uma serraria. O trabalho verificou a real potencialidade do uso da simulação no processo produtivo da serraria, se mostrando uma alternativa para o planejamento da produção da mesma. Com o uso da ferramenta estudada, o sistema produtivo foi modelado e validado utilizando o pacote de simulação Arena. Dentre os resultados desta dissertação, podem ser destacados: o modelo de pesquisa, a identificação das variáveis do sistema, o desenvolvimento e a validação do modelo. / The growing competition and the acceleration of technological advances have been contributing for the development of new production concepts and strategies, guiding companies into the search for continuous new business opportunities and productive processes improvements. Most of sawn wood industry in Brazil presents poor productive structure with low productivity, and its survival depends on the search for improvements on technical and economic efficiency of transformation processes. On this search, system simulation can be used as a supporting tool when deciding about the saw production planning, which contributes in favor of company competition. This paper work aims the development of a sawn wood production simulation model in order to help in the planning of a sawmill production. This work verifies the real potentiality when using the simulation during the sawmill productive process, which demonstrates it can be an alternative for the planning of the sawmill production. After using the above studied tool, the productive system was modeled and validated based on Arena simulation package. Among all the results of this study, some deserve to be highlighted: the research model, the identification of the system variables, and the model development and validation.
78

Hybrid intelligent decision support system for distributed detection based on ad hoc integrated WSN & RFID

Alshahrany, Falah January 2016 (has links)
The real time monitoring of environment context aware activities, based on distributed detection, is becoming a standard in public safety and service delivery in a wide range of domains (child and elderly care and supervision, logistics, circulation, and other). The safety of people, goods and premises depends on the prompt immediate reaction to potential hazards identified in real time, at an early stage to engage appropriate control actions. Effective emergency response can be supported only by available and acquired expertise or elaborate collaborative knowledge in the domain of distributed detection that include indoor sensing, tracking and localizing. This research proposes a hybrid conceptual multi-agent framework for the acquisition of collaborative knowledge in dynamic complex context aware environments for distributed detection. This framework has been applied for the design and development of a hybrid intelligent multi-agent decision system (HIDSS) that supports a decentralized active sensing, tracking and localizing strategy, and the deployment and configuration of smart detection devices associated to active sensor nodes wirelessly connected in a network topology to configure, deploy and control ad hoc wireless sensor networks (WSNs). This system, which is based on the interactive use of data, models and knowledge base, has been implemented to support fire detection and control access fusion functions aimed at elaborating: An integrated data model, grouping the building information data and WSN-RFID database, composed of the network configuration and captured data, A virtual layout configuration of the controlled premises, based on using a building information model, A knowledge-based support for the design of generic detection devices, A multi-criteria decision making model for generic detection devices distribution, ad hoc WSNs configuration, clustering and deployment, and Predictive data models for evacuation planning, and fire and evacuation simulation. An evaluation of the system prototype has been carried out to enrich information and knowledge fusion requirements and show the scope of the concepts used in data and process modelling. It has shown the practicability of hybrid solutions grouping generic homogeneous smart detection devices enhanced by heterogeneous support devices in their deployment, forming ad hoc networks that integrate WSNs and radio frequency identification (RFID) technology. The novelty in this work is the web-based support system architecture proposed in this framework that is based on the use of intelligent agent modelling and multi-agent systems, and the decoupling of the processes supporting the multi-sensor data fusion from those supporting different context applications. Although this decoupling is essential to appropriately distribute the different fusion functions, the integration of several dimensions of policy settings for the modelling of knowledge processes, and intelligent and pro-active decision making activities, requires the organisation of interactive fusion functions deployed upstream to a safety and emergency response.
79

Simulação da produção de madeira serrada

Heinrich, Daniele January 2010 (has links)
O aumento da competição e a aceleração dos avanços tecnológicos têm contribuído para o desenvolvimento de novos conceitos e estratégias de produção, direcionando as empresas à busca contínua de novas oportunidades de negócios e melhorias dos processos produtivos. A indústria de madeira serrada no Brasil, na sua grande maioria, apresenta estrutura produtiva precária, com baixa produtividade, e sua sobrevivência depende da busca por melhorias de eficiência técnica e econômica dos processos de transformação. Nesta busca de melhorias de processos, a simulação de sistemas pode ser utilizada como ferramenta de apoio à decisão no planejamento da produção de serrarias, contribuindo para a competitividade das empresas. Esta dissertação objetiva desenvolver um modelo de simulação da produção de madeira serrada para auxiliar no planejamento da produção de uma serraria. O trabalho verificou a real potencialidade do uso da simulação no processo produtivo da serraria, se mostrando uma alternativa para o planejamento da produção da mesma. Com o uso da ferramenta estudada, o sistema produtivo foi modelado e validado utilizando o pacote de simulação Arena. Dentre os resultados desta dissertação, podem ser destacados: o modelo de pesquisa, a identificação das variáveis do sistema, o desenvolvimento e a validação do modelo. / The growing competition and the acceleration of technological advances have been contributing for the development of new production concepts and strategies, guiding companies into the search for continuous new business opportunities and productive processes improvements. Most of sawn wood industry in Brazil presents poor productive structure with low productivity, and its survival depends on the search for improvements on technical and economic efficiency of transformation processes. On this search, system simulation can be used as a supporting tool when deciding about the saw production planning, which contributes in favor of company competition. This paper work aims the development of a sawn wood production simulation model in order to help in the planning of a sawmill production. This work verifies the real potentiality when using the simulation during the sawmill productive process, which demonstrates it can be an alternative for the planning of the sawmill production. After using the above studied tool, the productive system was modeled and validated based on Arena simulation package. Among all the results of this study, some deserve to be highlighted: the research model, the identification of the system variables, and the model development and validation.
80

Um sistema de apoio a decisão utilizado no planejamento e controle de produção de uma empresa aeronaútica / Reinaldo de Almeida. -

Almeida, Reinaldo de. January 2007 (has links)
Resumo: Este trabalho aborda o problema de identificação dos efeitos causados por eventuais falhas no abastecimento de certos materiais ou equipamentos na linha de montagem de aeronaves. Tal problema consiste em avaliar se o atraso na disponibilidade de um determinado material pode ser absorvido pela flexibilidade existente na rede de atividades da produção. Dessa forma, foi desenvolvido um sistema de apoio à decisão para o planejamento e controle da produção, utilizando simulação de eventos discretos para avaliar se o sincronismo entre os elos da cadeia produtiva está se comportando a contento e, em caso negativo, disponibilizar informações para as correções necessárias. A grande dificuldade na modelagem do sistema está na necessidade de integração de uma complexa cadeia de suprimentos a uma grande rede de atividades necessárias à manufatura das aeronaves. Apesar da complexidade, o sistema criado é capaz de identificar antecipadamente o impacto causado na montagem pelos insumos atrasados, além de prover uma visão de quais materiais, e respectivos fornecedores, apresentam um atraso que não pode ser absorvido pelo sistema, o que facilitaria o trabalho dos gestores da cadeia de suprimentos para aumentar a robustez do sistema. / Abstract: This work approaches the effects identification of problems caused by eventual fails in the provisioning of material or equipments in one assembly line of aircrafts. Such problem consists in evaluating if a delay in the availability of a material can be absorbed by the flexibility in the activities network of the production. This way, a decision support system was developed to support the planning and control of the production, using systems simulation, to evaluate if the synchronism among the links of the productive chain is behaving as necessary; in negative case, the system must to provide information for manager's action. The great difficulty to produce a model of this system is about the necessary integration of a complex supply chain to a big activities network associate to aircrafts manufacture. In spite of that complexity, the system developed is able to identify the impact caused in the assembly line by each late input, providing a vision of which materials, and respective suppliers, have a delay that cannot be absorbed by the production line. So, this research looks for facilitate the manager works in to increase the system robustness. / Orientador: Edgard Dias Batista Junior / Coorientador: Fernando Augusto da Silva Marins / Banca: José Antonio Perrella Balestieri / Banca: José Arnaldo Barra Montevechi / Mestre

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