• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 42
  • 34
  • 28
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 140
  • 140
  • 140
  • 140
  • 26
  • 26
  • 25
  • 24
  • 24
  • 23
  • 23
  • 21
  • 21
  • 21
  • 20
  • 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.
11

Development of a decision making model for the assessment of electricity demand side management in the State of Kuwait

Al-Ajmi, Abdullah A. January 2014 (has links)
Kuwait’s per capita electrical energy consumption is among the largest in the world, reaching 13,663 kWh per person in 2011. The electricity demand in Kuwait is increasing, which requires additional investments in power generation. A particular challenge in Kuwait is the peak demand in summer, when extreme heat increases air conditioning loads. Peak demand reached 11,220 MW in 2011, with a fast growth rate averaging 5.6% over the last decade and a maximum production capacity of around 14,720 MW. It is not possible to cope with this demand simply by increasing generation capacity. Therefore, the only alternative available to Kuwait is to control electricity demand via demand-side management. The main objective of this research is to assess and select the optimal demand- side management (DSM) technologies for buildings in the governmental sector (office, religious and school buildings) and to investigate the key factors in the evaluation process. To achieve the research objective, a model was proposed using multi-criteria decision-making techniques to enable the forecasting and comparison of DSM alternatives that are suitable for buildings. The developed model includes environmental, economic, technical and social considerations. The research methodology is based on three main phases. Phase 1: Data collection through a mail questionnaire that was sent to 42 experts for the identification of criteria and demand-side management alternatives. Phase 2: Screening and narrowing of the data collected in Phase 1 using a set of questionnaires, including the identification of potential DSM alternatives and criteria suitable for further analysis. This phase was performed through the Delphi process, taking into consideration the opinions of 28 experts. Phase 3: Use of Multi-criteria Decision Making (MCDM) techniques, namely the Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP), to evaluate and rank the identified DSM alternatives and criteria. This was done using pairwise comparisons of 17 experts to evaluate the criteria and alternatives for the buildings (office, religious and school). The research showed that the experts identified six alternative technologies and five criteria for the selection and evaluation of governmental buildings (office, religious and school). After performing the three phases of this research project, a set of criteria and alternatives were ranked based on the information gathered from every group of experts. It was found that reduction in consumption, capital cost and ease of implementation were the three most recommended criteria for the selection of DSM technologies in Kuwait government buildings while high efficiency lighting and programmable thermostats were identified as the most recommended DSM technologies for these buildings. An important aspect of this research is that unlike engineering approaches which sometimes depend on expensive test equipment or, often for building design, expensive computer modelling exercises, the proposed framework can be easily adopted by anyone without any significant financial cost. The FAHP approach was also tested and its results compared with those of AHP. There was a slight difference between using AHP and FAHP in terms of ranking the criteria and alternatives but that the difference barely affects the ranking. It was found that the AHP provides a convenient MCDM approach for solving the complex problem of selecting the optimal DSM options for buildings. The contributions of this thesis are the development of a novel framework for systematic selection and ranking of DSM technologies in different types of buildings using the Delphi method and AHP; the identification of the most important DSM technologies and criteria for their selection for three types of governmental buildings in Kuwait; and establishing that results from using AHP and FAHP for the selection of appropriate DSM measures in these buildings are almost identical, so use of AHP is likely to be sufficient in most building studies of this type.
12

Using Mutli Criteria Decision Analysis To Develop Sustainability Assessment Tools: Biomass Supply Chains

Perruccio, Deandra Marie 01 January 2015 (has links)
Energy access remains a significant challenge in nations lacking access to resources and strong infrastructure systems, creating barriers to economic development and to increased standards of living. Small scale biomass gasification energy (BGE) systems have been developed to meet energy needs in rural areas, creating synergies between agricultural and agro-forestry systems through utilization of biomass feedstock for energy generation. The sustainability of such systems requires sophisticated planning and coordination of the biomass supply chain. The goal of this thesis is to investigate and improve structural and process related characteristics of sustainability assessments for small scale bio-energy systems, specifically focusing on establishment and management of biomass supply chains through the development and dissemination of a generic sustainability assessment framework for biomass supply chains of small-scale BGE systems in rural East Africa. Building on a preliminary sustainability assessment framework (Christensen, 2013; Joerg, 2013) this research develops an assessment tool designed to capture sustainability requirements of the biomass supply chain in the ecological, social, and economic spheres through testing on three case studies in rural Uganda. Application and analysis of a preliminary framework on pilot projects in a rural east African context using Multi Criteria Decision Analysis (MCDA) methodologies contributes to development of strategies for energy system analysis and building stakeholder capacity to incorporate social, economic, and environmental considerations. The assessment process is outlined, including scoring, data collection, contextual considerations. Model application is discussed, including the impact of weighting on decision outcomes, uncertainty management, sensitivity analysis, and identification of tradeoffs among criteria. Finally, discussion of tool usefulness verses usability contributes to bridging academic research with practitioner priorities.
13

Modely vícekriteriálního rozhodování v analýze obalu dat / Multi-Criteria Decision Making in Data Envelopment Analysis

Mec, Martin January 2009 (has links)
Data Envelopment Analysis is a multi-criteria decision making tool employing set of minimizing criteria (inputs) and set of maximizing criteria (outputs) for evaluating decision making unit efficiency. This method is accompanied by problems in field of input and output weight assignment, whereas benevolent basic model formulation enables decision making unit evaluation to be based on far unevenly distributed weight vector. Furthermore, data envelopment analysis basic model produces dichotomized dividing in form of efficient and inefficient decision making unit sets. Extensive set of efficient units occurs frequently and this causes difficulties in choosing one or less number efficient units. These phenomena appear often simultaneously. An implementation of multi-criteria decision making models into data envelopment analysis is exercised in order to reduce these undesired effects in applications.
14

A Comprehensive Framework Approach using Content, Context, Process Views to Combine Methods from Operations Research for IT Assessments

Bernroider, Edward, Koch, Stefan, Stix, Volker January 2013 (has links) (PDF)
Motivated by IT evaluation problems identified in a large public sector organization, we propose how evaluation requirements can be supported by a framework combining different models and methods from IS evaluation theory. The article extends the content, context, process (CCP) perspectives of organizational change with operations research techniques and demonstrates the approach in practice for an Enterprise Resource Planning evaluation.
15

Vytvoření aplikace k porovnání států pomocí metod vícekriteriálního rozhodování / VBA Application for Country Comparation by using Multi-Criteria Decision Making Methods

Hlaváček, Michal January 2011 (has links)
The aim of this work is to create an application in VBA to compare countries using multi-criteria decision making methods. The main methods, mentioned in the theoretical part are implemented in the application. In theoretical part there are also compared different multi-criteria decision making methods. This work also describes macroeconomic criteria, weigths and the selection of countries. The aim of the final part is the analysis of country comparison results.
16

Vícekriteriální hodnocení hypoték / Multi-criteria evaluation of mortgages

Suchanová, Romana January 2010 (has links)
The aim of this thesis is to find suitable mortgage, describe important criteria for comparison of mortgages and what types of mortgages the banks offer. The theoretical part of the thesis is divided into four parts. At first, I describe methods of determining the weights and methods of multi-criteria decision making. Then I focus on information about mortgage loan and about loan application process. In the third part I present variants and criteria and in the fourth I detect the best mortgage. I used WSA, TOPSIS, ELECTRE III and MAPPAC and add-on of Microsoft Excel - Sanna.
17

Application of AHP Decision-Making Method for Selecting a 4-axis Machining Center: A Case Study in Mold and Die Industry

Tsai, Jo-Peng 26 July 2008 (has links)
Selection of the right machine tools is an important decision for most manufacturing companies. The quality and efficiency of manufacture are affected by the correct adoption of machine and equipment, and it will result in reducing the cost, increasing the production, and enhancing the flexibility for the diverse type of machining parts in this competitive globalized environment. On the contrary, an incorrect selection can retard the productivity of company. This research presents the procedures of AHP method for selecting 4-axis CNC machining centers including searching the literature of selecting machines, consulting experts with abundant experience of machine tool, translating the unstructured and biased commercial specification to the objective and hierarchical evaluation criteria for selecting machines. In order to experiment the applicability of the AHP model as well as to realize the relative importance of the criteria for the mold design and manufacturing company, a company was invited as the survey objective. This method proposed in this research is general in form and can be applied to the selections of other machine tools for other manufacturing industries. Also, it is hoped that the results of this experimental study will provide a reference for the domestic machinery manufacturing company to develop 4-axis CNC machining centers.
18

Método multicriterial para seleção de processos de fundição de metais

Setti, Dalmarino January 2010 (has links)
O objetivo principal da tese foi desenvolver um método multicriterial de seleção de processos de fundição de metais (MMSPF) para fabricação de componentes, considerando-se critérios técnicos, ambientais e econômicos para ser aplicado nas fases iniciais do desenvolvimento do componente. O MMSPF é constituído pelos módulos de seleção técnica e econômica. O módulo de seleção técnica é destinado a antecipar as atividades de seleção de processos, a serem desenvolvidas na fase de projeto preliminar, enquanto o módulo de seleção econômica é destinado a antecipar as atividades de seleção de processos, necessárias à fase de projeto detalhado. O MMSPF realiza a seleção de processos de forma sequencial. Inicialmente, avaliando aspectos técnicos e, posteriormente, considerando aspectos econômicos. O MMSPF contempla as seis classes de ligas metálicas mais utilizadas na produção de componentes fundidos: aços, ferros fundidos, ligas de alumínio, ligas de cobre, ligas de magnésio e ligas de zinco, apropriadas aos processos de fundição de metais destinados à produção de peças. O MMSPF contempla os quinze principais processos de fundição de metais destinados a produção de peças: areia verde – manual (P1), areia verde – mecanizada (P2), areia verde – automatizada (P3), areia silicato - CO2 (P4), areia com resina – cura frio (P5), areia com resina – shell molding (P6), processo molde de gesso – plaster molding (P7), processo molde cerâmico (P8), investment casting (P9), molde cheio - lost foam (P10), fundição centrífuga - molde metálico (P11), molde permanente – gravidade (P12), molde permanente - baixa pressão (P13), fundição sob pressão - die casting (P14) e squeeze casting (P15) como conjunto solução da seleção. As inovações propostas pelo MMSPF foram: (i) consolidação das diferentes fontes de informação dos processos a serem utilizadas no MMSPF, por meio de uma função de agregação; (ii) utilização de aspectos ambientais como critérios para seleção de processos de fundição de metais; (iii) consideração da estimação de custos de fabricação para realizar a seleção de processos de fundição de metais a partir de um índice de custo de fabricação, relativo ao desempenho técnico. Também foi desenvolvido um aplicativo computacional para implementar o MMSPF composto por três elementos principais: um software de planilha eletrônica (Microsoft Excel), no qual são realizadas todas as operações matemáticas necessárias ao desenvolvimento das etapas operacionais do MMSPF; um banco de dados, o software livre SQLite, responsável por armazenar as informações utilizadas no aplicativo computacional do MMSPF; e a interface gráfica do usuário, que atua como elemento de conexão entre o banco de dados, o software de planilha eletrônica e o usuário. / The main objective of this thesis was to develop a Multi-criteria Method for metal Casting Process Selection (MMCPS) to manufacturing components, considering technical criteria, environmental and economic to be applied in the early stages of design of the component. The MMCPS consists modules for the technical and economic selection. The technique selection module is designed to anticipate the activities of processes selection to be developed in the embodiment design, while the economic selection module is designed to anticipate selection process activities, necessary the detailed design phase. The MMCPS conducts the selection process sequentially. Initially, evaluating technical aspects and, subsequently, considering economic aspects. The MMCPS includes the six classes of metal alloys more used in the production of cast components: steel, cast iron, aluminum alloys, copper alloys, magnesium alloys and zinc alloys, suitable for metal shape casting processes. The MMCPS covers the fifteen main metal shape casting processes: green sand – hand molding (P1), green sand – mechanized molding (P2), green sand - automatic molding (P3), silicate-CO2 (P4), air-set/nobake (P5), shell molding (P6), plaster molding (P7), ceramic mold (P8), investment casting (P9), lost foam (P10), centrifugal casting – metallic mold (P11), permanent mold-gravity (P12), permanent mold-low pressure (P13), die casting (P14) and squeeze casting (P15) as the set solution for the selection process. The innovations proposed by MMCPS were: (i) consolidation of different sources of information processes to be used in MMCPS through an aggregation function; (ii) use of environmental aspects as criteria for selection of metal casting processes; (iii) consideration of the cost estimation of manufacturing to make the metal casting process selection from an index of manufacturing cost on the technical performance. Also developed a computational tool to implement the MMCPS composed of three main elements: a spreadsheet software (Microsoft Excel), which are held every mathematical operations necessary for the development of operational steps MMCPS; a database, freeware SQLite, responsible for storing information used in the application of computational MMCPS, and the graphical user interface, which acts as a link between the database, the spreadsheet software and the user.
19

Método multicriterial para seleção de processos de fundição de metais

Setti, Dalmarino January 2010 (has links)
O objetivo principal da tese foi desenvolver um método multicriterial de seleção de processos de fundição de metais (MMSPF) para fabricação de componentes, considerando-se critérios técnicos, ambientais e econômicos para ser aplicado nas fases iniciais do desenvolvimento do componente. O MMSPF é constituído pelos módulos de seleção técnica e econômica. O módulo de seleção técnica é destinado a antecipar as atividades de seleção de processos, a serem desenvolvidas na fase de projeto preliminar, enquanto o módulo de seleção econômica é destinado a antecipar as atividades de seleção de processos, necessárias à fase de projeto detalhado. O MMSPF realiza a seleção de processos de forma sequencial. Inicialmente, avaliando aspectos técnicos e, posteriormente, considerando aspectos econômicos. O MMSPF contempla as seis classes de ligas metálicas mais utilizadas na produção de componentes fundidos: aços, ferros fundidos, ligas de alumínio, ligas de cobre, ligas de magnésio e ligas de zinco, apropriadas aos processos de fundição de metais destinados à produção de peças. O MMSPF contempla os quinze principais processos de fundição de metais destinados a produção de peças: areia verde – manual (P1), areia verde – mecanizada (P2), areia verde – automatizada (P3), areia silicato - CO2 (P4), areia com resina – cura frio (P5), areia com resina – shell molding (P6), processo molde de gesso – plaster molding (P7), processo molde cerâmico (P8), investment casting (P9), molde cheio - lost foam (P10), fundição centrífuga - molde metálico (P11), molde permanente – gravidade (P12), molde permanente - baixa pressão (P13), fundição sob pressão - die casting (P14) e squeeze casting (P15) como conjunto solução da seleção. As inovações propostas pelo MMSPF foram: (i) consolidação das diferentes fontes de informação dos processos a serem utilizadas no MMSPF, por meio de uma função de agregação; (ii) utilização de aspectos ambientais como critérios para seleção de processos de fundição de metais; (iii) consideração da estimação de custos de fabricação para realizar a seleção de processos de fundição de metais a partir de um índice de custo de fabricação, relativo ao desempenho técnico. Também foi desenvolvido um aplicativo computacional para implementar o MMSPF composto por três elementos principais: um software de planilha eletrônica (Microsoft Excel), no qual são realizadas todas as operações matemáticas necessárias ao desenvolvimento das etapas operacionais do MMSPF; um banco de dados, o software livre SQLite, responsável por armazenar as informações utilizadas no aplicativo computacional do MMSPF; e a interface gráfica do usuário, que atua como elemento de conexão entre o banco de dados, o software de planilha eletrônica e o usuário. / The main objective of this thesis was to develop a Multi-criteria Method for metal Casting Process Selection (MMCPS) to manufacturing components, considering technical criteria, environmental and economic to be applied in the early stages of design of the component. The MMCPS consists modules for the technical and economic selection. The technique selection module is designed to anticipate the activities of processes selection to be developed in the embodiment design, while the economic selection module is designed to anticipate selection process activities, necessary the detailed design phase. The MMCPS conducts the selection process sequentially. Initially, evaluating technical aspects and, subsequently, considering economic aspects. The MMCPS includes the six classes of metal alloys more used in the production of cast components: steel, cast iron, aluminum alloys, copper alloys, magnesium alloys and zinc alloys, suitable for metal shape casting processes. The MMCPS covers the fifteen main metal shape casting processes: green sand – hand molding (P1), green sand – mechanized molding (P2), green sand - automatic molding (P3), silicate-CO2 (P4), air-set/nobake (P5), shell molding (P6), plaster molding (P7), ceramic mold (P8), investment casting (P9), lost foam (P10), centrifugal casting – metallic mold (P11), permanent mold-gravity (P12), permanent mold-low pressure (P13), die casting (P14) and squeeze casting (P15) as the set solution for the selection process. The innovations proposed by MMCPS were: (i) consolidation of different sources of information processes to be used in MMCPS through an aggregation function; (ii) use of environmental aspects as criteria for selection of metal casting processes; (iii) consideration of the cost estimation of manufacturing to make the metal casting process selection from an index of manufacturing cost on the technical performance. Also developed a computational tool to implement the MMCPS composed of three main elements: a spreadsheet software (Microsoft Excel), which are held every mathematical operations necessary for the development of operational steps MMCPS; a database, freeware SQLite, responsible for storing information used in the application of computational MMCPS, and the graphical user interface, which acts as a link between the database, the spreadsheet software and the user.
20

Método multicriterial para seleção de processos de fundição de metais

Setti, Dalmarino January 2010 (has links)
O objetivo principal da tese foi desenvolver um método multicriterial de seleção de processos de fundição de metais (MMSPF) para fabricação de componentes, considerando-se critérios técnicos, ambientais e econômicos para ser aplicado nas fases iniciais do desenvolvimento do componente. O MMSPF é constituído pelos módulos de seleção técnica e econômica. O módulo de seleção técnica é destinado a antecipar as atividades de seleção de processos, a serem desenvolvidas na fase de projeto preliminar, enquanto o módulo de seleção econômica é destinado a antecipar as atividades de seleção de processos, necessárias à fase de projeto detalhado. O MMSPF realiza a seleção de processos de forma sequencial. Inicialmente, avaliando aspectos técnicos e, posteriormente, considerando aspectos econômicos. O MMSPF contempla as seis classes de ligas metálicas mais utilizadas na produção de componentes fundidos: aços, ferros fundidos, ligas de alumínio, ligas de cobre, ligas de magnésio e ligas de zinco, apropriadas aos processos de fundição de metais destinados à produção de peças. O MMSPF contempla os quinze principais processos de fundição de metais destinados a produção de peças: areia verde – manual (P1), areia verde – mecanizada (P2), areia verde – automatizada (P3), areia silicato - CO2 (P4), areia com resina – cura frio (P5), areia com resina – shell molding (P6), processo molde de gesso – plaster molding (P7), processo molde cerâmico (P8), investment casting (P9), molde cheio - lost foam (P10), fundição centrífuga - molde metálico (P11), molde permanente – gravidade (P12), molde permanente - baixa pressão (P13), fundição sob pressão - die casting (P14) e squeeze casting (P15) como conjunto solução da seleção. As inovações propostas pelo MMSPF foram: (i) consolidação das diferentes fontes de informação dos processos a serem utilizadas no MMSPF, por meio de uma função de agregação; (ii) utilização de aspectos ambientais como critérios para seleção de processos de fundição de metais; (iii) consideração da estimação de custos de fabricação para realizar a seleção de processos de fundição de metais a partir de um índice de custo de fabricação, relativo ao desempenho técnico. Também foi desenvolvido um aplicativo computacional para implementar o MMSPF composto por três elementos principais: um software de planilha eletrônica (Microsoft Excel), no qual são realizadas todas as operações matemáticas necessárias ao desenvolvimento das etapas operacionais do MMSPF; um banco de dados, o software livre SQLite, responsável por armazenar as informações utilizadas no aplicativo computacional do MMSPF; e a interface gráfica do usuário, que atua como elemento de conexão entre o banco de dados, o software de planilha eletrônica e o usuário. / The main objective of this thesis was to develop a Multi-criteria Method for metal Casting Process Selection (MMCPS) to manufacturing components, considering technical criteria, environmental and economic to be applied in the early stages of design of the component. The MMCPS consists modules for the technical and economic selection. The technique selection module is designed to anticipate the activities of processes selection to be developed in the embodiment design, while the economic selection module is designed to anticipate selection process activities, necessary the detailed design phase. The MMCPS conducts the selection process sequentially. Initially, evaluating technical aspects and, subsequently, considering economic aspects. The MMCPS includes the six classes of metal alloys more used in the production of cast components: steel, cast iron, aluminum alloys, copper alloys, magnesium alloys and zinc alloys, suitable for metal shape casting processes. The MMCPS covers the fifteen main metal shape casting processes: green sand – hand molding (P1), green sand – mechanized molding (P2), green sand - automatic molding (P3), silicate-CO2 (P4), air-set/nobake (P5), shell molding (P6), plaster molding (P7), ceramic mold (P8), investment casting (P9), lost foam (P10), centrifugal casting – metallic mold (P11), permanent mold-gravity (P12), permanent mold-low pressure (P13), die casting (P14) and squeeze casting (P15) as the set solution for the selection process. The innovations proposed by MMCPS were: (i) consolidation of different sources of information processes to be used in MMCPS through an aggregation function; (ii) use of environmental aspects as criteria for selection of metal casting processes; (iii) consideration of the cost estimation of manufacturing to make the metal casting process selection from an index of manufacturing cost on the technical performance. Also developed a computational tool to implement the MMCPS composed of three main elements: a spreadsheet software (Microsoft Excel), which are held every mathematical operations necessary for the development of operational steps MMCPS; a database, freeware SQLite, responsible for storing information used in the application of computational MMCPS, and the graphical user interface, which acts as a link between the database, the spreadsheet software and the user.

Page generated in 0.0384 seconds