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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.
111

Determining sustainable lignocellulosic bioenergy systems in the Cape Winelands District Municipality, South Africa

Von Doderer, Clemens Cornelius Christian 12 1900 (has links)
Thesis (PhD(Agric))--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The energy paradigm shift from fossil fuels to renewable energy sources is driven, among others, by a growing sustainability awareness, necessitating more sophisticated measurements in terms of a wider range of criteria. Technical efficiency, financial profitability, environmental friendliness and social acceptance are some of the factors determining the sustainability of renewable energy systems. The resulting complexity and conflicting decision criteria, however, constitute major barriers to processing the information and decision-making based on the information. Seeking to implement local bioenergy systems, policymakers of the Cape Winelands District Municipality (CWDM), South Africa, are confronted with such a problem. Following a case study approach, this study illustrates how life-cycle assessment (LCA), multi-period budgeting (MPB) and geographic information systems (GIS) can aid the decision-making process by providing financial-economic, socio-economic and environmental friendliness performance data in a structured and transparent manner, allowing for a comparison of the magnitude of each considered criterion along the life-cycle. However, as the environmental impacts cannot readily be expressed in monetary terms on a cardinal scale, these considerations are given less attention or are omitted completely in a market economy. By measuring the various considerations on an ordinal scale and by attaching weights to them using the multi-criteria decision analysis (MCDA) approach, this study, illustrates how to internalise externalities as typical market failures, aiding policymakers of the CWDM to choose the most sustainable bioenergy system. Following the LCA approach, 37 lignocellulosic bioenergy systems, encompassing different combinations of type of harvesting and primary transport, type of pretreatment (comminution, drying, and fast pyrolysis) and location thereof (roadside or landing of the central conversion plant), type of secondary transport from the roadside to the central conversion plant, and type of biomass upgrading and conversion into electricity, were assessed against five financial-economic viability criteria, three socio-economic potential criteria and five environmental impact criteria. The quantitative performance data were then, as part of the MCDA process, translated into a standardised ‘common language’ of relative performance. An expert group attached weights to the considered criteria using the analytical hierarchy process (AHP). The ‘financial-economic viability’ main criterion received a weight of almost 60%, ‘socio-economic potential’, nearly 25% and ‘lowest environmental impact’, the remainder of around 16%. Taking the prerequisite of financial-economic viability into consideration, the preferred option across all areas of the CWDM (despite various levels of productivity) comprises a feller-buncher for harvesting, a forwarder for primary transportation, mobile comminution at the roadside, secondary transport in truck-container-trailer combinations and an integrated gasification system for the conversion into electricity. / AFRIKAANSE OPSOMMING: Die energie paradigma verandering van fossielbrandstowwe na hernubare energiebronne word gedryf deur ‘n groeiende klem op volhoubaarheid, wat ook meer gesofistikeerde meting in terme van ‘n wyer verskeidenheid maatstawwe vereis. Tegniese doeltreffendheid, finansiële winsgewendheid, omgewingsvriendelikheid en sosiale aanvaarbaarheid is sommige van die faktore wat die volhoubaarheid van hernubare energie stelsels bepaal. Die verskeidenheid oorwegings bring egter kompleksiteit en konflik mee by die verwerking van inligting en die besluitneming wat daarop berus. Beleidmakers van die Kaapse Wynland Distriksmunisipaliteit wat ten doel het om plaaslik bio-energie stelsels te implementeer, word met hierdie probleem gekonfronteer. Hierdie ondersoek illustreer aan die hand van ‘n gevallestudie benadering hoe lewensiklus analise, multiperiode begroting en geografiese inligtingstelsels besluitneming kan ondersteun deur die voorsiening van finansieel-ekonomiese, sosio-ekonomiese (indiensneming) en omgewingsvriendelikheid prestasie data op ‘n gestruktureerde en deursigtige wyse. Dit maak die vergelyking van die waardes van al die kriteria by elke fase van die lewensiklus moontlik. Aangesien die omgewingseffekte nie geredelik in monetêre terme op ‘n kardinale skaal gemeet kan word nie, kry hulle binne die markekonomie minder aandag of word selfs buite rekening gelaat. Deur hierdie verskeidenheid kriteria op ‘n ordinale skaal te meet en gewigte met behulp van multikriteria besluitneming aan hulle toe te ken, toon hierdie ondersoek hoe om eksternaliteite as tipiese markmislukkings te internaliseer om beleidmakers van die Kaapse Wynland Distriksmunisipaliteit in staat te stel om die mees volhoubare bio-energie stelsel te kies. Met behulp van lewensiklus analise is 37 lignosellulose bio-energie stelsels geïdentifiseer as verskillende kombinasies van oes van die bome, primêre vervoer van houtstompe, vooraf verwerking (verspaandering, droging, vinnige pirolise), die ligging van hierdie aktiwiteite (langs ‘n plantasie of by ‘n sentrale omsettingsaanleg), tipe sekondêre vervoer van houtspaanders vanaf die plantasie na die sentrale omsettingsaanleg en tipe biomassa opgradering en omsetting van die houtspaanders na elektrisiteit. Die verskillende stelsels is gemeet aan die hand van vyf finansieel-ekonomiese kriteria, drie indiensneming potensiaal kriteria en vyf omgewingsimpak kriteria. Die kwantitatiewe metings is deur middel van multikriteria besluitneming omgeskakel na ’n gestandaardiseerde “gemeenskaplike taal” van relatiewe prestasie. Lede van ‘n ekspertgroep het gewigte is aan die onderskeie kriteria met behulp van die analitiese hierargie proses toegeken. Aan die finansieel-ekonomiese lewensvatbaarheid hoof kriterium is ‘n gewig van by die 60% toegeken, aan die indiensnemingspotensiaal bykans 25% en aan omgewingsvriendelikheid sowat 16%. Die voorkeur kombinasie vir al die areas van die Kaapse Wynland Distriksmunisipaliteit sluit in ‘n saag-bondelaar vir die oesproses, ‘n plantasie-vragmotor vir primêre vervoer, mobiele verspaandering langs die plantasie, ‘n vragmotor-skeepshouer-treiler kombinasies vir die sekondêre vervoer van houtspaanders en ‘n geïntegreerde vergassingstelsel vir die omsetting van houtspaanders na elektrisiteit.
112

Hodnocení investičních možností PRE do malých vodních elektráren / Investment evaluation of small hydropower projects in PRE

Kovaříková, Lenka January 2010 (has links)
In recent years the greater emphasis is placed on the renewable energy sources that are environmentally friendly. Demand for renewable energy sources is supported by government incentives, which leads to an increasing pace of investment in this sector. Prices for electricity from renewable energies are far higher than the prices of conventional electricity. If the current trend continues, it is only a matter of time before they meet. According to this fact, PRE Company decided to invest in hydropower. This thesis deals with identifying of potential investment opportunities in small hydropower plants from the PRE point of view and the subsequent evaluation of these variants on the basis of multi-criteria decision making.
113

Proposta de modelo de decisão para avaliação de fornecedores baseado no ELECTRE TRI para categorização e na teoria dos conjuntos fuzzy para a modelagem da incerteza e hesitação de múltiplos tomadores de decisão / Proposal of decision model for supplier evaluation based on ELECTRE TRI for categorization and fuzzy sets theory for the modeling of uncertainty and hesitation of multiple decision makers

Galo, Nadya Regina 19 April 2018 (has links)
A gestão eficaz dos processos que envolvem os fornecedores tem grande influência na melhoria do desempenho organizacional, sendo, portanto, fundamental para desenvolver capacidades das operações de produção que podem gerar vantagem competitiva, tais como qualidade, preço e tempo de entrega. A gestão de fornecedores inclui as atividades de qualificação, seleção, avaliação e desenvolvimento de fornecedores, além da alocação de pedido quando múltiplas fontes de fornecimento são selecionadas. A qualificação é um processo importante para assegurar que os fornecedores atendam requisitos mínimos de desempenho e, idealmente, deve ser realizada com métodos não compensatórios de categorização das alternativas. Entretanto, na literatura há poucos estudos que abordam a qualificação de fornecedores. Dentre aqueles que abordam, a maioria utiliza técnicas multicritério que são compensatórias e de ordenação. Outros aspectos importantes da gestão de fornecedores é a possível presença vários tomadores de decisão, caracterizando um processo de tomada de decisão em grupo, além da subjetividade de alguns critérios que gera incerteza nos julgamentos e hesitação. Ao se considerar essas questões na gestão de fornecedores, nenhuma pesquisa na literatura apresenta uma abordagem que contemple todos as características simultaneamente. Além disso, poucas pesquisas abordam os processos da gestão de fornecedores sob uma perspectiva integrada. Com vista a estas lacunas, esta pesquisa tem por objetivo a proposição de dois modelos de decisão que consideram os processos de qualificação, seleção e avaliação de fornecedores, em um cenário de tomada de decisão em grupo, considerando a incerteza e hesitação. Os modelos propostos têm por finalidade elicitar as preferências, agregar os julgamentos e categorizar os fornecedores. O primeiro modelo utiliza a representação linguística Triangular Hesitant Fuzzy Sets, para lidar com a hesitação nos julgamentos dos tomadores de decisão, além da técnica ELECTRE TRI para a categorização dos fornecedores. O segundo modelo se baseia na aplicação representação linguística Intuitionistic Fuzzy Sets para modelar a hesitação na parametrização das variáveis linguísticas e no ELECTRE TRI para a categorização. A elicitação é realizada com o uso do Fuzzy Delphi combinado com operadores de agregação do Triangular Hesitant Fuzzy Sets e Intuitionistic Fuzzy Sets. Os modelos de decisão foram detalhados e implementados no Matlab©. Após a proposição dos métodos, dois casos ilustrativos, obtidos a partir da coleta em campo, foram apresentados para analisar o desempenho dos modelos. Os casos ilustrativos mostraram resultados de categorização consistentes, especialmente para o procedimento pessimista do ELECTRE TRI. Testes com a hesitação nos julgamentos dos tomadores de decisão evidenciaram a importância da modelagem da hesitação, pois ela tem o potencial de alterar a categorização das alternativas. Testes com os parâmetros do ELECTRE TRI, confirmaram o efeito não compensatório da técnica e que a variação do nível de corte tem o potencial de tornar a categorização mais flexível. Assim, esta tese apresenta uma revisão de literatura sobre os processos de gestão de fornecedores e sobre tomada de decisão multicritério e em grupo, a proposição de métodos de apoio à tomada de decisão, casos ilustrativos para ilustrar o modelo, análises de sensibilidade dos métodos, além das conclusões e propostas para trabalhos futuros. / Effective management of the processes that involving suppliers has a major influence on improving organizational performance and is therefore fundamental to develop production operations capabilities that can generate competitive advantage, such as quality, price and delivery time. Supplier management includes qualification, selection, evaluation and development of suppliers, as well as allocation of orders when multiple sources of supply are selected. Qualification is an important process to ensure that suppliers meet minimum performance requirements and ideally must be performed with non-compensatory methods of categorization. However, in the literature there are few studies that consider the process of supplier qualification. Among the studies that consider the qualification, most use multicriteria techniques that are compensatory and for ranking. Other important aspects of supplier management are the possible presence of several decision makers, characterizing a process of group decision making, as well as the subjectivity of some criteria that generates uncertainty in judgments and hesitation. When considering these issues in supplier management, none of the studies found in the literature presents an approach that contemplates all features simultaneously. In addition, few researches deal with supplier management processes from an integrated perspective. In view of these gaps, this research aims to propose two decision models that consider the processes of qualification, selection and evaluation of suppliers, in a scenario of group decision making, considering the uncertainty and hesitation. The proposed models have the purpose the elicitation of the preferences, the aggregation of the judgments and the categorization of the suppliers. The first model uses the linguistic representation Triangular Hesitant Fuzzy Sets, to deal with the hesitation in the judgments of the decision makers, in addition to the ELECTRE TRI technique for the categorization of the suppliers. The second model is based on the application of the linguistic representation Intuitionistic Fuzzy Sets to model the hesitation in the parameterization of the linguistic variables and in the ELECTRE TRI for categorization. Elicitation is performed with the use of Fuzzy Delphi combined with aggregation operators of the Triangular Hesitant Fuzzy Sets and Intuitionistic Fuzzy Sets. The decision models were detailed and implemented in Matlab©. Two illustrative cases, obtained from the field collection, were presented to analyze the performance of the models. The illustrative cases showed consistent categorization results, especially for the pessimistic procedure of ELECTRE TRI. Tests with hesitation in the judgments of decision makers highlighted the importance of modeling hesitation, since it has the potential to change the categorization of alternatives. Tests with the ELECTRE TRI parameters confirmed the non-compensatory effect of the technique and that the variation of the cut level has the potential to make categorization more flexible. Thus, this thesis presents a review of the literature on supplier management processes and on multicriteria and group decision making, the proposition of methods to support decision making, illustrative cases to illustrate the model, method sensitivity analyzes, besides the conclusions and proposals for future works.
114

[en] MEASUREMENT AND EVALUATION OF INTANGIBLE ASSETS AND VALUE CREATION OF DIAGNOSIS AND TESTING LABORATORIES FOR ELECTRICAL EQUIPMENTS / [pt] MENSURAÇÃO E AVALIAÇÃO DOS ATIVOS INTANGÍVEIS E CRIAÇÃO DE VALOR DAS ATIVIDADES DE LABORATÓRIOS DE DIAGNÓSTICO E ENSAIOS DE EQUIPAMENTOS ELÉTRICOS

ARNOLDO FURTADO DE SA 20 February 2019 (has links)
[pt] Dentre os objetivos do Plano Estratégico do Sistema Eletrobras, destacam-se a intensificação da atuação integrada em pesquisa, desenvolvimento e inovação (PD e I) e a mensuração dos ativos tangíveis e intangíveis para geração de valor para o Sistema Eletrobras. Nesse contexto, esta pesquisa buscou contribuir para o aprimoramento da gestão de ativos intangíveis no âmbito da Rede de Laboratórios das Empresas Eletrobras (Relase), ao tornar disponível um modelo de mensuração e avaliação de ativos intangíveis desenvolvido para laboratórios de diagnóstico e ensaios de equipamentos elétricos. A pesquisa pode ser considerada descritiva, metodológica e aplicada. A partir dos resultados da revisão bibliográfica e documental sobre os temas centrais da pesquisa, adaptou-se, para fins de aplicação em laboratórios de diagnóstico e ensaios de equipamentos elétricos, um modelo conceitual que já vem sendo adotado por instituições de Ciência e Tecnologia europeias para elaboração de seus relatórios de capital intelectual. Para a proposição e seleção dos indicadores e métricas que integram o modelo, empregaram-se métodos multicritério de apoio à decisão combinados com lógica fuzzy. A aplicabilidade do modelo pôde ser demonstrada mediante um estudo empírico no Laboratório de Diagnóstico em Equipamentos e Instalações Elétricas (Labdig) do Centro de Pesquisas de Energia Elétrica (Cepel). Considera-se que o ferramental desenvolvido por esta pesquisa possa ser replicado no âmbito da Relase, que abrange hoje um total de 98 laboratórios, sendo 16 destes acreditados para serviços de calibração. / [en] Among the objectives of the Eletrobras System Strategic Plan, two of them are highlighted – the intensification of the integrated practice in research, development and innovation (RD and I); and the measurement of tangible and intangible assets to generate value for the Eletrobras System. In this context, this dissertation aims at contributing to the improvement of the management of intangible assets within the Eletrobras Companies Laboratories Network (Relase – Rede de Laboratórios das Empresas Eletrobras), by providing an intangible asset measurement and assessment model developed for electrical equipment diagnosis and testing laboratories. The research can be considered descriptive, methodological and applied. Based on the results of the bibliographic review and documentary analysis on the central themes of the research, a conceptual model was adapted for the context of diagnosis and testing laboratories, which has already been adopted by European Science and Technology institutions concerning elaboration of their intellectual capital reports. In this research, for the proposal and selection of indicators and metrics, multicriteria decision support methods were incorporated into the model, combined with fuzzy logic. The applicability of the model has been demonstrated through an empirical study in the Laboratório de Diagnóstico em Equipamentos e Instalações Elétricas (Labdig) do Centro de Pesquisas de Energia Elétrica (Cepel). The results of this research can be replicated within Relase, which covers today a total of 98 laboratories, of which 16 are accredited for calibration services.
115

Proposta de modelo de decisão para avaliação de fornecedores baseado no ELECTRE TRI para categorização e na teoria dos conjuntos fuzzy para a modelagem da incerteza e hesitação de múltiplos tomadores de decisão / Proposal of decision model for supplier evaluation based on ELECTRE TRI for categorization and fuzzy sets theory for the modeling of uncertainty and hesitation of multiple decision makers

Nadya Regina Galo 19 April 2018 (has links)
A gestão eficaz dos processos que envolvem os fornecedores tem grande influência na melhoria do desempenho organizacional, sendo, portanto, fundamental para desenvolver capacidades das operações de produção que podem gerar vantagem competitiva, tais como qualidade, preço e tempo de entrega. A gestão de fornecedores inclui as atividades de qualificação, seleção, avaliação e desenvolvimento de fornecedores, além da alocação de pedido quando múltiplas fontes de fornecimento são selecionadas. A qualificação é um processo importante para assegurar que os fornecedores atendam requisitos mínimos de desempenho e, idealmente, deve ser realizada com métodos não compensatórios de categorização das alternativas. Entretanto, na literatura há poucos estudos que abordam a qualificação de fornecedores. Dentre aqueles que abordam, a maioria utiliza técnicas multicritério que são compensatórias e de ordenação. Outros aspectos importantes da gestão de fornecedores é a possível presença vários tomadores de decisão, caracterizando um processo de tomada de decisão em grupo, além da subjetividade de alguns critérios que gera incerteza nos julgamentos e hesitação. Ao se considerar essas questões na gestão de fornecedores, nenhuma pesquisa na literatura apresenta uma abordagem que contemple todos as características simultaneamente. Além disso, poucas pesquisas abordam os processos da gestão de fornecedores sob uma perspectiva integrada. Com vista a estas lacunas, esta pesquisa tem por objetivo a proposição de dois modelos de decisão que consideram os processos de qualificação, seleção e avaliação de fornecedores, em um cenário de tomada de decisão em grupo, considerando a incerteza e hesitação. Os modelos propostos têm por finalidade elicitar as preferências, agregar os julgamentos e categorizar os fornecedores. O primeiro modelo utiliza a representação linguística Triangular Hesitant Fuzzy Sets, para lidar com a hesitação nos julgamentos dos tomadores de decisão, além da técnica ELECTRE TRI para a categorização dos fornecedores. O segundo modelo se baseia na aplicação representação linguística Intuitionistic Fuzzy Sets para modelar a hesitação na parametrização das variáveis linguísticas e no ELECTRE TRI para a categorização. A elicitação é realizada com o uso do Fuzzy Delphi combinado com operadores de agregação do Triangular Hesitant Fuzzy Sets e Intuitionistic Fuzzy Sets. Os modelos de decisão foram detalhados e implementados no Matlab©. Após a proposição dos métodos, dois casos ilustrativos, obtidos a partir da coleta em campo, foram apresentados para analisar o desempenho dos modelos. Os casos ilustrativos mostraram resultados de categorização consistentes, especialmente para o procedimento pessimista do ELECTRE TRI. Testes com a hesitação nos julgamentos dos tomadores de decisão evidenciaram a importância da modelagem da hesitação, pois ela tem o potencial de alterar a categorização das alternativas. Testes com os parâmetros do ELECTRE TRI, confirmaram o efeito não compensatório da técnica e que a variação do nível de corte tem o potencial de tornar a categorização mais flexível. Assim, esta tese apresenta uma revisão de literatura sobre os processos de gestão de fornecedores e sobre tomada de decisão multicritério e em grupo, a proposição de métodos de apoio à tomada de decisão, casos ilustrativos para ilustrar o modelo, análises de sensibilidade dos métodos, além das conclusões e propostas para trabalhos futuros. / Effective management of the processes that involving suppliers has a major influence on improving organizational performance and is therefore fundamental to develop production operations capabilities that can generate competitive advantage, such as quality, price and delivery time. Supplier management includes qualification, selection, evaluation and development of suppliers, as well as allocation of orders when multiple sources of supply are selected. Qualification is an important process to ensure that suppliers meet minimum performance requirements and ideally must be performed with non-compensatory methods of categorization. However, in the literature there are few studies that consider the process of supplier qualification. Among the studies that consider the qualification, most use multicriteria techniques that are compensatory and for ranking. Other important aspects of supplier management are the possible presence of several decision makers, characterizing a process of group decision making, as well as the subjectivity of some criteria that generates uncertainty in judgments and hesitation. When considering these issues in supplier management, none of the studies found in the literature presents an approach that contemplates all features simultaneously. In addition, few researches deal with supplier management processes from an integrated perspective. In view of these gaps, this research aims to propose two decision models that consider the processes of qualification, selection and evaluation of suppliers, in a scenario of group decision making, considering the uncertainty and hesitation. The proposed models have the purpose the elicitation of the preferences, the aggregation of the judgments and the categorization of the suppliers. The first model uses the linguistic representation Triangular Hesitant Fuzzy Sets, to deal with the hesitation in the judgments of the decision makers, in addition to the ELECTRE TRI technique for the categorization of the suppliers. The second model is based on the application of the linguistic representation Intuitionistic Fuzzy Sets to model the hesitation in the parameterization of the linguistic variables and in the ELECTRE TRI for categorization. Elicitation is performed with the use of Fuzzy Delphi combined with aggregation operators of the Triangular Hesitant Fuzzy Sets and Intuitionistic Fuzzy Sets. The decision models were detailed and implemented in Matlab©. Two illustrative cases, obtained from the field collection, were presented to analyze the performance of the models. The illustrative cases showed consistent categorization results, especially for the pessimistic procedure of ELECTRE TRI. Tests with hesitation in the judgments of decision makers highlighted the importance of modeling hesitation, since it has the potential to change the categorization of alternatives. Tests with the ELECTRE TRI parameters confirmed the non-compensatory effect of the technique and that the variation of the cut level has the potential to make categorization more flexible. Thus, this thesis presents a review of the literature on supplier management processes and on multicriteria and group decision making, the proposition of methods to support decision making, illustrative cases to illustrate the model, method sensitivity analyzes, besides the conclusions and proposals for future works.
116

Statistical And Spatial Approaches To Marina Master Plan For Turkey

Karanci, Ayse 01 February 2011 (has links) (PDF)
Turkey, with its climate, protected bays, cultural and environmental resources is an ideal place for yacht tourism. Subsequently, yacht tourism is increasing consistently. Yacht tourism can cause unmitigated development and environmental concerns when aiming to achieve tourist satisfaction. As the demand for yacht tourism intensifies, sustainable development strategies are needed to maximize natural, cultural and economic benefits. Integration of forecasts to the strategic planning is necessary for sustainable and use of the coastal resources. In this study two different quantitative forecasting techniques - Exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) methods were used to estimate the demand for yacht berthing capacity demand till 2030 in Turkey. Based on environmental, socio-economic and geographic data and the opinions gathered from stakeholders such as marina operators, local communities and government officials an allocation model was developed for the successful allocation of the predicted demand seeking social and economical growth while preserving the coastal environment. AHP was used to identify and evaluate the development, social and environmental and geographic priorities. Aiming a dynamic plan which is responsive to both national and international developments in yacht tourism, potential investment areas were determined for the investments required to accommodate the future demand. This study provides a multi dimensioned point of view to planning problem and highlights the need for sustainable and dynamic planning at delicate and high demand areas such as coasts.
117

Fan And Pitch Angle Selection For Efficient Mine Ventilation Using Analytical Hierachy Process And Neuro Fuzzy Approach

Taghizadeh Vahed, Amir 01 May 2012 (has links) (PDF)
Ventilation is a critical task in underground mining operation. Lack of a good ventilation system causes accumulation of harmful gases, explosions, and even fatalities. A proper ventilation system provides adequate fresh air to miners for a safe and comfortable working environment. Fans, which provide air flow to different faces of a mine, have great impact in ventilation systems. Thus, selection of appropriate fans for a mine is the acute task. Unsuitable selection of a fan decreases safety and production rate, which increases capital and operational costs. Moreover, pitch angle of fans&rsquo / blades plays an important role in fan&rsquo / s efficiency. Therefore, selection of a fan and its pitch angle, which yields the maximum efficiency, is an emerging issue for an efficient mine ventilation. The main objective of this research study is to provide a decision making methodology for the selection of a main fan and its appropriate pitch angle for efficient mine ventilation. Nowadays, analytical hierarchy process as multi criteria decision making is used, and it yields outputs based on pairwise comparison. On the other hand, Fuzzy Logic as a soft computing method was combined with analytical hierarchy process and combined model did not yield appropriate results / because Fuzzy AHP increased uncertainty ratio in this study. However, fuzzy analytical hierarchy process might be inapplicable when it faces with vague and complex data set. Soft computing methods can be utilized for complicated situations. One of the soft computing methods is a Neuro-Fuzzy algorithm which is used in classification and DM issues. This study has two phases: i) selection of an appropriate fan using Analytical Hierarchy Process (AHP) and Fuzzy Analytical Hierarchy Process (Fuzzy AHP) and ii) selection of an appropriate pitch angle using Neuro-Fuzzy algorithm and Fuzzy AHP method. This study showed that AHP can be effectively utilized for main fan selection. It performs better than Fuzzy AHP because FAHP contains more expertise and makes problems more complex for evaluating. When FAHP and Neuro-Fuzzy is compared for pitch angle selection, both methodologies yielded the same results. Therefore, utilization of Neuro-Fuzzy in situation with complicated and vague data will be applicable.
118

Vibrational spectroscopy of keratin fibres : A forensic approach

Panayiotou, Helen January 2004 (has links)
Human hair profiling is an integral part of a forensic investigation but it is one of the most technically difficult subjects in forensic science. This thesis describes the research and development of a novel approach for the rapid identification of unknown human and other related keratin fibres found at a crime scene. The work presented here is developed systematically and considers sample collection, sample preparation, analysis and interpretation of spectral data for the profiling of hair fibres encountered in criminal cases. Spectral comparison of fibres was facilitated with the use of chemometrics methods such as PCA, SIMCA and Fuzzy Clustering, and the less common approach of multi-criteria decision making methodology (MCDM). The aim of the thesis was to investigate the potential of some vibrational spectroscopy techniques for matching and discrimination of single keratin hair fibres in the context of forensic evidence. The first objective (chapter 3) of the thesis was to evaluate the use of Raman and FT-IR micro-spectroscopy techniques for the forensic sampling of hair fibres and to propose the preferred technique for future forensic hair comparisons. The selection of the preferred technique was based on criteria such as spectral quality, ease of use, rapid analysis and universal application to different hair samples. FT-IR micro-spectroscopy was found to be the most appropriate technique for hair analysis because it enabled the rapid collection of spectra from a wide variety of hair fibres. Raman micro-spectroscopy, on the other hand, was hindered with fluorescence problems and did not allow the collection of spectra from pigmented fibres. This objective has therefore shown that FT-IR micro-spectroscopy is the preferable spectroscopic technique for forensic analysis of hair fibres, whilst Raman spectroscopy is the least preferred. The second objective (chapter 3) was to investigate, through a series of experiments, the effect of chemical treatment on the micro-environment of human hair fibres. The effect of bleaching agents on the hair fibres was studied with some detail at different treatment times and the results indicate a significant change in the chemical environment of the secondary structure of the hair fibre along with changes in the C-C backbone structure. One of the most important outcomes of this research was the behaviour of the fÑ-helix during chemical treatment. The hydrogen bonding in the fÑ-helix provides for the stable structure of the fibre and therefore any disruption to the fÑ-helix will inevitably damage the molecular structure of the fibre. The results highlighted the behaviour of the fÑ-helix, which undergoes a significant decrease in content during oxidation, and is partly converted to a random-coil structure, whilst the fÒ-sheet component of the secondary structure remains unaffected. The reported investigations show that the combination of FT-IR and Raman micro-spectroscopy can provide an insight and understanding into the complex chemical properties and reactions within a treated hair fibre. Importantly, this work demonstrates that with the aid of chemometrics, it is possible to investigate simultaneously FT-IR and Raman micro-spectroscopic information from oxidised hair fibres collected from one subject and treated at different times. The discrimination and matching of hair fibres on the basis of treatment has potential forensic applications. The third objective (chapter 4) attempted to expand the forensic application of FT-IR micro-spectroscopy to other keratin fibres. Animal fibres are commonly encountered in crime scenes and it thus becomes important to establish the origin of those fibres. The aim of this work was to establish the forensic applications of FT-IR micro-spectroscopy to animal fibres and to investigate any fundamental molecular differences between these fibres. The results established a discrimination between fibres consisting predominantly of fÑ-helix and those containing mainly a fÒ-sheet structure. More importantly, it was demonstrated through curve-fitting and chemometrics, that each keratin fibre contains a characteristic secondary structure arrangement. The work presented here is the first detailed FT-IR micro-spectroscopic study, utilising chemometrics as well as MCDM methods, for a wide range of keratin fibres, which are commonly, found as forensic evidence. Furthermore, it was demonstrated with the aid of the rank ordering MCDM methods PROMETHEE and GAIA, that it is possible to rank and discriminate keratin fibres according to their molecular characteristics obtained from direct measurements together with information sourced from the literature. The final objective (chapter 5) of the thesis was to propose an alternative method for the discrimination and matching of single scalp human hair fibres through the use of FT-IR micro-spectroscopy and chemometrics. The work successfully demonstrated, through a number of case scenarios, the application of the technique for the identification of variables such as gender and race for an unknown single hair fibre. In addition, it was also illustrated that known hair fibres (from the suspect or victim) can be readily matched to the unknown hair fibres found at the crime scene. This is the first time that a substantial, systematic FT-IR study of forensic hair identification has been presented. The research has shown that it is possible to model and correlate individual¡¦s characteristics with hair properties at molecular level with the use of chemometrics methods. A number of different, important forensic variables of immediate use to police in a crime scene investigation such as gender, race, treatment, black and white hair fibres were investigated. Blind samples were successfully applied both to validate available experimental data and extend the current database of experimental determinations. Protocols were posed for the application of this methodology in the future. The proposed FT-IR methodology presented in this thesis has provided an alternative approach to the characterisation of single scalp human hair fibres. The technique enables the rapid collection of spectra, followed by the objective analytical capabilities of chemometrics to successfully discriminate animal fibres, human hair fibres from different sources, treated from untreated hair fibres, as well as black and white hair fibres, on the basis of their molecular structure. The results can be readily produced and explained in the courts of law. Although the proposed relatively fast FT-IR technique is not aimed at displacing the two slower existing methods of hair analysis, namely comparative optical microscopy and DNA analysis, it has given a new dimension to the characterisation of hair fibres at a molecular level, providing a powerful tool for forensic investigations.
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An automated multi criteria assembly line design generation method for decision making support : an automotive case study / Ανάπτυξη μεθόδου λήψης αποφάσεων για τον σχεδιασμό συστημάτων παραγωγής : εφαρμογή στην αυτοκινητοβιομηχανία

Μίχαλος, Γεώργιος 14 February 2012 (has links)
The objective of the present study is the development of a method for the automated design of assembly lines using a multiple criteria approach. This method aims at supporting the decision making process during the early design stages as well as during the reconfiguration stages of assembly lines. Towards this target, a complete approach is proposed investigating the aspects of the design problem in both human and automation based assembly lines. At first, the current practices for design /reconfiguration of automated/ human based assembly lines were analysed and the decision making process was modelled in each case. Following the design problem was formulated in a way that allows its solution by the use of search algorithms which are easier and more efficient to apply. Models capable of systematically generating the alternative assembly lines designs were designed and implemented. An intelligent search algorithm was applied to these models allowing the efficient exploration of the design problem solution space and the fast identification of high quality design solutions with respect to several user defined criteria (such as investment cost, flexibility etc.). All the aforementioned were incorporated into two distinct software tools, having as objective the support of assembly line design and reconfiguration. The first tool incorporates the design model and algorithms in a standalone application that can automatically generate, simulate and evaluate alternative assembly lines designs based on the product structure and the available equipment and processes. The second tool was developed as a web based application that allows the reconfiguration of human based assembly lines through the concept of dynamic job rotation. The tool is able to derive alternative rotation schedules and evaluate them against criteria that are used for the case of human based assembly lines. The main outcome of this work is the complete method that was proposed and realized through software tools, which is capable of providing solutions for the design and reconfiguration of assembly lines. The method can assist design engineers in real time through the automated generation, evaluation and identification of high quality design alternatives. The evaluation of the case studies revealed the efficiency of the suggested approach to produce such designs and validated its applicability to industrial environments. / Το αντικείμενο αυτής της διατριβής είναι η ανάπτυξη μια πολυκριτηριδιακής μεθόδου για την αυτοματοποίηση της διαδικασίας σχεδιασμού γραμμών συναρμολόγησης. Η μέθοδος προορίζεται για την υποστήριξη της διαδικασίας λήψης αποφάσεων τόσο κατά τα αρχικά στάδια του σχεδιασμού όσο και κατά τον επανασχεδιασμό / αναδιαμόρφωση της γραμμής παραγωγής. Προς αυτή την κατεύθυνση προτείνεται μια ολοκληρωμένη προσέγγιση του προβλήματος η οποία εξετάζει τις ιδιαιτερότητες τόσο των αυτοματοποιημένων γραμμών συναρμολόγησης όσο και των γραμμών που απασχολούν ανθρώπινο δυναμικό. Αρχικά, ερευνήθηκαν οι σημερινές πρακτικές που χρησιμοποιούνται στο σχεδιασμό αυτοματοποιημένων συστημάτων παραγωγής αλλά και των γραμμών που βασίζονται στο ανθρώπινο δυναμικό. Κατόπιν οι διαδικασίες αυτές μοντελοποιούνται με αποτέλεσμα, την ανάπτυξη μοντέλων, τα οποία είναι ικανά να παράγουν με συστηματικό τρόπο εναλλακτικούς σχεδιασμούς μιας γραμμής συναρμολόγησης. Επιπρόσθετα, ένας ευφυής αλγόριθμος εφαρμόζεται στα μοντέλα αυτά, επιτρέποντας την αποδοτική και γρηγορότερη ανάδειξη σχεδιασμών υψηλής ποιότητας ως προς τα κριτήρια που έχει θέσει ο σχεδιαστής. Τα παραπάνω μοντέλα και ο αλγόριθμος αναζήτησης υλοποιήθηκαν σε δύο λογισμικά εργαλεία που αναπτύχθηκαν, με στόχο την στήριξη του σχεδιασμού γραμμών παραγωγής. Το πρώτο εργαλείο αποτελεί ένα αυτοτελές λογισμικό το οποίο έχει ως κύρια λειτουργία του την δημιουργία και αξιολόγηση εναλλακτικών σχεδιασμών αυτοματοποιημένων γραμμών παραγωγή, χρησιμοποιώντας ως εισόδους την δομή του προϊόντος και τον διαθέσιμο εξοπλισμό. Το δεύτερο εργαλείο χρησιμοποιεί την τεχνολογία των ιστοσελίδων (web interface) και χρησιμοποιείται για την δημιουργία χρονοπρογραμμάτων για τους εργάτες μιας γραμμής παραγωγής επιτρέποντας την αναδιαμόρφωση της σε σύντομο χρονικό διάστημα. Η ερευνητική συμβολή της παρούσας διατριβής έγκειται στην ανάπτυξη μεθόδου η οποία προσφέρει ολοκληρωμένη λύση για την υποστήριξη λήψης αποφάσεων κατά τον σχεδιασμό και την αναδιαμόρφωση γραμμών συναρμολόγησης και υλοποιείται μέσω των κατάλληλων εργαλείων λογισμικού. Η αξιολόγηση των περιπτώσεων της αυτοκινητοβιομηχανίας απέδειξε την αποδοτικότητα και εφαρμοσιμότητά της σε βιομηχανικό περιβάλλον.
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Aplicação de método de tomada de decisão multicritério para priorização de projetos Lean Six Sigma / Application of multi-criteria decision-making method for Lean Six Sigma projects prioritization

Rolando, Daniel Augusto Rainha [UNESP] 16 February 2018 (has links)
Submitted by DANIEL AUGUSTO RAINHA ROLANDO null (danielrolando@gmail.com) on 2018-04-05T16:00:00Z No. of bitstreams: 1 Dissertação_Rolando-DAR.pdf: 3156622 bytes, checksum: ac92904a2c656de7add0c53bd32f6e49 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-04-06T18:54:51Z (GMT) No. of bitstreams: 1 rolando_dar_me_guara.pdf: 3156622 bytes, checksum: ac92904a2c656de7add0c53bd32f6e49 (MD5) / Made available in DSpace on 2018-04-06T18:54:51Z (GMT). No. of bitstreams: 1 rolando_dar_me_guara.pdf: 3156622 bytes, checksum: ac92904a2c656de7add0c53bd32f6e49 (MD5) Previous issue date: 2018-02-16 / Para a delimitação de um processo de tomada de decisão na escolha de projetos Lean Six Sigma, é necessário definir os fatores críticos, tanto de sucesso (como por exemplo: envolvimento e comprometimento da gestão, entendimento das ferramentas e técnicas do Lean Six Sigma, ligação do projeto com a estratégia de negócios) quanto de fracasso (como por exemplo a falta do envolvimento da gestão, resistência à mudança cultural, inexistência de gestão de projetos). Desta forma, este trabalho foi conduzido por meio de modelagem com validação de dados reais, com o objetivo de propor uma adaptação de métodos de auxílio à tomada a decisão para seleção de projetos Lean Six Sigma baseado nos fatores críticos de sucesso e fracasso. Para tanto, com base na revisão da literatura, foram identificados os fatores críticos de sucesso e fracasso para seleção de projetos Lean Six Sigma. Em seguida, uma análise de dois métodos de tomada de decisão multicritério, PROMETHEE e ANP, foi realizada por meio da aplicação dos modelos em um portfólio de projetos de uma empresa multinacional de grande porte. Como resultado, houve assertividade de 95% na seleção dos melhores projetos do portfólio, comparado aos projetos executados pela empresa mostrando-se que os dois modelos são aderentes ao problema. Como resultado, é possível constatar que o PROMETHEE se mostrou mais assertivo, principalmente nas comparações quantitativas, tendo aplicabilidade tanto para decisões individuais quanto em grupos. O ANP, por fazer a análise de preferência dos critérios de forma pareada (utilizando a escala comparativa de Saaty) torna mais fácil seu em grupos grandes de decisores, porém a comparação utilizando a escala de Saaty dificulta a análise de critérios quantitativos, bem como para pequenos grupos ou em decisões individuais. / To define a decision-making process in the Lean Six Sigma projects’ choice, it is necessary to define the critical success factors (e. g., management involvement and commitment, understanding the tools and techniques of Lean Six Sigma methodologies), and critical failure factors (e. g., lack of management involvement, cultural change resistance, project management weakness, etc.). In this way, this work was conducted through the modeling method with the objective of proposing an adaptation of decision-making aid methods process to select Lean Six Sigma projects based on the critical success and critical failure factors. Therefore, based on the literature review, the critical success and critical failure factors for the selection of Lean Six Sigma projects were identified. An analysis of two multi-criteria decision-making methods, PROMETHEE and ANP, was performed through the application of the models in a project portfolio of a large multinational company, presenting 95% assertiveness in the selection of the best portfolio projects compared to the executed projects by the company, showing that the two models are adherent to the problem. In addition, PROMETHEE has been more assertive, mainly in quantitative comparisons, and the use of the method are applied for both individual and group decisions; the ANP, by doing the preference analysis of the criteria in pair-to-pair way, using the Saaty’s comparative scale, makes it easier in large groups of decision makers. However, the comparison using the Saaty scale makes it difficult to analyze quantitative criteria as well as small groups or in individual decisions

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