1,042 research outputs found

    Fuzzy Techniques for Decision Making 2018

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    Zadeh's fuzzy set theory incorporates the impreciseness of data and evaluations, by imputting the degrees by which each object belongs to a set. Its success fostered theories that codify the subjectivity, uncertainty, imprecision, or roughness of the evaluations. Their rationale is to produce new flexible methodologies in order to model a variety of concrete decision problems more realistically. This Special Issue garners contributions addressing novel tools, techniques and methodologies for decision making (inclusive of both individual and group, single- or multi-criteria decision making) in the context of these theories. It contains 38 research articles that contribute to a variety of setups that combine fuzziness, hesitancy, roughness, covering sets, and linguistic approaches. Their ranges vary from fundamental or technical to applied approaches

    Methodology for the evaluation and design of projects considering multiple criteria and uncertainty. Application to the development of energy projects in rural areas

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    Tesi en modalitat de compendi de publicacionsIn 2015, the United Nations defined the Sustainable Development Goals in a transition towards a world without poverty and where human rights, equity and sustainability are prioritized. In particular, modern energy services are considered crucial not only to achieve universal access to energy by 2030, but due to their contribution to alleviate chronical poverty, reduce food insecurity, promote the access to modern information in schools and enhance the start of productive activities. However, the aim of global access by 2030 is still far from being complete, with more than 700 million people living in rural areas without access to electricity and using firewood and other polluting traditional biomass for cooking and heating. Decentralized energy systems are gaining attention as a more feasible solution than grid extension to provide energy to rural and inaccessible areas. The evaluation and design of decentralized systems is a complex process that needs to take into account multiple alternatives and criteria to ensure a long-term sustainability, but usually available studies in literature focus exclusively in technical and economic aspects. Also, the minority of studies following a multicriteria decision-making approach underestimate the effect of the potential lack of confidence of the experts and users consulted to weight the importance of each criterion or to evaluate a specific alternative. In this context, the objective of this thesis is to develop multicriteria procedures considering uncertainty to increase the robustness of the results. These procedures are applied to projects that foster access to energy services and promote therefore the development of rural and underprivileged areas. The thesis begins with two multicriteria procedures presented for the evaluation and the design, respectively, of rural electrification projects. These procedures are applied to two real case studies in Peru and Nigeria. Both applications provide valuable insights, for local authorities and other promoters of electrification systems in similar contexts, regarding which technologies and configurations to use in determined circumstances. At the same time, the analysis carried out enable an improvement regarding the robustness of results through the consideration of the lack of confidence of the opinions collected about the importance of the criteria and the evaluation of the alternatives. In this regard, A Methodology for Multicriteria Decision-making considering Uncertainty (MIMDU) is then developed based on fuzzy numbers to include the lack of confidence experts and users might have when weighting a criterion or evaluating an alternative. The methodology designed includes a novel procedure to quantify human opinions with non-pre-defined fuzzy numbers and a systematic process to calculate diverse rankings of alternatives and provide complimentary information that leads to a more robust decision-making. Indeed, the potential of the methodology is illustrated with an example case that shows how the lack of confidence can affect the alternatives ranking and the subsequent decision. Finally, the methodology is applied to a real case study in Colombia to select the best alternative for digestate post-treatment before its application to agricultural soil as a fertilizer. The use of MIMDU presents three major beneficial outcomes for multicriteria decision-making to foster rural development. First, the consideration of the lack of confidence of the respondents can reduce the pressure they might feel when providing an answer without complete knowledge. Second, it allows a more accurate quantification of the opinions given, turning, for example, more hesitant answers into less reliable evaluations of an alternative, that worsens its final ranking. And third, more robust decisions can be taken due to the major precision in the modelling of opinions and the possibility of comparing crisp and fuzzy-based rankings of the alternatives.Dins dels objectius de desenvolupament sostenibles, els serveis energètics moderns es consideren crucials no només per aconseguir l'accés universal a l'energia el 2030, sinó per la seva contribució a pal·liar la pobresa crònica, reduir la inseguretat alimentària, promoure l'accés a la informació moderna a les escoles i permetre l'inici d'activitats productives. Tot i això, l’objectiu d’accés mundial per al 2030 encara està lluny d’acomplir-se, ja que més de 700 milions de persones viuen a les zones rurals sense accés a l’electricitat i utilitzen llenya i altres biomasses tradicionals contaminants per cuinar i escalfar. Els sistemes energètics descentralitzats guanyen pes respecte l’extensió de la xarxa per proporcionar energia a zones rurals i inaccessibles. L’avaluació i el disseny d’aquests sistemes és un procés complex que ha de tenir en compte múltiples alternatives i criteris per garantir una sostenibilitat a llarg termini, però els estudis de literatura disponibles generalment se centren exclusivament en aspectes tècniques i econòmiques. A més, la minoria d’estudis que segueixen un enfocament multicriteri subestimen l’efecte de la manca de confiança potencial dels experts i usuaris consultats per ponderar la importància de cada criteri o avaluar una alternativa específica. En aquest context, l'objectiu d'aquesta tesi és desenvolupar procediments multicriteri considerant la incertesa per afavorir l’obtenció de resultats robustos. Aquests procediments s’apliquen a projectes que afavoreixen l’accés als serveis energètics i promouen, per tant, el desenvolupament de zones rurals i desfavorides. La tesi comença amb dos procediments multicriteri presentats per a l'avaluació i el disseny, respectivament, de projectes d'electrificació rural. Aquests procediments s'apliquen a dos casos pràctics reals al Perú i Nigèria. Ambdues aplicacions proporcionen informació valuosa, per a les autoritats locals i altres promotors de sistemes d’electrificació en contextos similars, sobre quines tecnologies i configuracions a utilitzar en determinades circumstàncies. Al mateix temps, les anàlisis realitzades permeten una millora en quant a la solidesa dels resultats mitjançant la consideració de la manca de confiança de les opinions recollides sobre la importància dels criteris i l’avaluació de les alternatives. Per fer-ho, es desenvolupa una metodologia per a la presa de decisions multicriteri que té en compte la incertesa (MIMDU) basada en nombres difusos per incloure la manca de confiança que els experts i usuaris podrien tenir quan ponderen un criteri o avaluen una alternativa. La metodologia dissenyada inclou un nou procediment per quantificar opinions humanes amb nombres difusos no predefinits i un procés sistemàtic per calcular diversos rànquings d’alternatives i proporcionar informació complementària que condueix a una presa de decisions més robusta. De fet, el potencial de la metodologia s’il·lustra amb un cas d’exemple que mostra com la manca de confiança pot afectar el rànquing d’alternatives i la decisió posterior. Finalment, la metodologia s'aplica a un estudi de cas real a Colòmbia per seleccionar la millor alternativa per al post-tractament del digestat abans de la seva aplicació a sòl agrícola com a fertilitzant. L’ús de MIMDU presenta tres grans beneficis per a la presa de decisions multicriteri per fomentar el desenvolupament rural. En primer lloc, la consideració de la manca de confiança dels enquestats pot reduir la pressió que podrien sentir al donar una resposta sense coneixement complet. En segon lloc, permet una quantificació més precisa de les opinions donades, convertint, per exemple, respostes més dubtoses en avaluacions menys fiables d’una alternativa, que empitjora la seva classificació final. I, en tercer lloc, es poden prendre decisions més robustes a causa de la precisió en la modelització d’opinionsEn 2015, la Organización de las Naciones Unidas definió los Objetivos de Desarrollo Sostenible en una transición hacia un mundo sin pobreza y donde se priorizan los derechos humanos, la equidad y la sostenibilidad. En particular, los servicios energéticos modernos se consideran cruciales no solo para lograr el acceso universal a la energía en 2030, sino por su contribución para aliviar la pobreza crónica, reducir la inseguridad alimentaria, promover el acceso a la información en las escuelas y permitir el inicio de actividades productivas. Sin embargo, el objetivo de acceso global a la energía para 2030 aún está lejos de ser completo, con más de 700 millones de personas viviendo en áreas rurales sin acceso a electricidad y utilizando leña y otra biomasa tradicional contaminante, para cocinar y calentar. Los sistemas de energía descentralizados están ganando peso respecto a la extensión de la red para proporcionar energía a áreas rurales e inaccesibles. La evaluación y el diseño de sistemas descentralizados es un proceso complejo que precisa considerar múltiples alternativas y criterios para que sea sostenible a largo plazo, pero los estudios disponibles en la literatura generalmente se enfocan exclusivamente en aspectos técnicos y económicos. Asimismo, la minoría de estudios que siguen un enfoque de toma de decisiones multicriterio subestiman el efecto de la potencial falta de confianza de los expertos y usuarios consultados para ponderar la importancia de cada criterio o para evaluar una alternativa específica. En este contexto, el objetivo de esta tesis es desarrollar procedimientos multicriterio considerando la incertidumbre para aumentar la robustez de los resultados. Estos procedimientos se aplican a proyectos que fomentan el acceso a los servicios energéticos y, por tanto, promueven el desarrollo de zonas rurales y desfavorecidas. La tesis comienza con dos procedimientos multicriterio presentados para la evaluación y el diseño, respectivamente, de proyectos de electrificación rural. Estos procedimientos se aplican a dos estudios de casos reales en Perú y Nigeria. Ambas aplicaciones pueden proporcionar información valiosa, para las autoridades locales y otros promotores de sistemas de electrificación en contextos similares, sobre qué tecnologías y configuraciones utilizar en determinadas circunstancias. Al mismo tiempo, los análisis realizados permiten una mejora en cuanto a la robustez de los resultados a través de la consideración de la falta de confianza de las opiniones recogidas acerca de la importancia de los criterios y de la evaluación de las alternativas. Para ello, se desarrolla una Metodología para la toma de decisiones multicriterio considerando la incertidumbre (MIMDU) basada en números difusos para incluir la falta de confianza que los expertos y los usuarios pueden tener al ponderar un criterio o evaluar una alternativa La metodología diseñada incluye un procedimiento novedoso para cuantificar opiniones humanas con números difusos no predefinidos y un proceso sistemático para proponer rankings de alternativas y brindar información complementaria que conduce a una toma de decisiones más robusta. El potencial de la metodología se ilustra con un caso de ejemplo que muestra cómo la falta de confianza puede afectar el ranking de alternativas y la decisión posterior. Finalmente, la metodología diseñada se aplica a un estudio de caso real en Colombia para seleccionar la mejor alternativa para el digestato post-tratamiento previo a su aplicación al suelo agrícola como fertilizante. El uso de MIMDU presenta tres importantes beneficios para la toma de decisiones multicriterio en contextos de desarrollo rural. En primer lugar, la consideración de la falta de confianza de los encuestados puede reducir la presión al dar una respuesta sin un conocimiento completo. En segundo lugar, permite una cuantificación más precisa de las opiniones emitidas, convirtiendo, por ejemplo, respuestas más vacilantes en valoraciones menos fiables de una alternativa, que empeora su clasificación final. Y tercero, se pueden tomar decisiones más sólidas debido a la mayor precisión en el modelado de opiniones y la posibilidad de comparar rankings deterministas y difusos de las alternativas.Postprint (published version

    Fuzzy Mathematics

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    This book provides a timely overview of topics in fuzzy mathematics. It lays the foundation for further research and applications in a broad range of areas. It contains break-through analysis on how results from the many variations and extensions of fuzzy set theory can be obtained from known results of traditional fuzzy set theory. The book contains not only theoretical results, but a wide range of applications in areas such as decision analysis, optimal allocation in possibilistics and mixed models, pattern classification, credibility measures, algorithms for modeling uncertain data, and numerical methods for solving fuzzy linear systems. The book offers an excellent reference for advanced undergraduate and graduate students in applied and theoretical fuzzy mathematics. Researchers and referees in fuzzy set theory will find the book to be of extreme value

    Full Issue

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    Decision analysis in the UK energy supply chain risk management: tools development and application.

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    The aims of this thesis are developing decision-making tools for risk identification, risk causal relationships analysis, risk prioritisation, and long-term risk mitigation strategy recommendations in the UK energy supply chain. The thesis is comprised of four study phases in eight chapters. In phase I, a framework is introduced including 12 risk dimensions, and 5 classification perspectives. Then, in phase II, the Neutrosophic Revised Decision-Making Trial and Evaluation Laboratory (NR-DEMATEL) method has been utilised in order to analyse the 12 identified risk dimensions based on the causal interrelationships between them. Additionally, a novel Hesitant Expert Selection Model (HESM) to systematically assist researchers with the expert selection process is proposed. In phase III, two extensions of the original Best-Worst Method (BWM) are proposed in order to contribute to the theoretical development and application of the BWM in energy supply chain risk prioritisation. The Neutrosophic Enhanced BWM (NE-BWM) and hybrid Spanning Trees Enumeration and BWM (STE-BWM) are introduced to enhance the efficiency of the original BWM in dealing with uncertainty in experts’ subjective judgements. In phase IV, a novel stratified decision-making model is introduced. It is based on Concept of Stratification (CST), game theory and Shared Socio-economic Pathway (SSP) to deal with long-term risk mitigation planning for the most critical identified risks. The model has been applied in the region of Highland and Argyll in Scotland based on the primary data obtained from experts to prioritise flooding risk mitigation strategies which were recommended by the Scottish Environment Protection Agency (SEPA). The stratified decision-making model is aimed at taking into account both UK socio-economic situations and flooding risk impacts for the long-term decision making

    Uncertain Multi-Criteria Optimization Problems

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    Most real-world search and optimization problems naturally involve multiple criteria as objectives. Generally, symmetry, asymmetry, and anti-symmetry are basic characteristics of binary relationships used when modeling optimization problems. Moreover, the notion of symmetry has appeared in many articles about uncertainty theories that are employed in multi-criteria problems. Different solutions may produce trade-offs (conflicting scenarios) among different objectives. A better solution with respect to one objective may compromise other objectives. There are various factors that need to be considered to address the problems in multidisciplinary research, which is critical for the overall sustainability of human development and activity. In this regard, in recent decades, decision-making theory has been the subject of intense research activities due to its wide applications in different areas. The decision-making theory approach has become an important means to provide real-time solutions to uncertainty problems. Theories such as probability theory, fuzzy set theory, type-2 fuzzy set theory, rough set, and uncertainty theory, available in the existing literature, deal with such uncertainties. Nevertheless, the uncertain multi-criteria characteristics in such problems have not yet been explored in depth, and there is much left to be achieved in this direction. Hence, different mathematical models of real-life multi-criteria optimization problems can be developed in various uncertain frameworks with special emphasis on optimization problems

    Fuzzy Sets in Business Management, Finance, and Economics

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    This book collects fifteen papers published in s Special Issue of Mathematics titled “Fuzzy Sets in Business Management, Finance, and Economics”, which was published in 2021. These paper cover a wide range of different tools from Fuzzy Set Theory and applications in many areas of Business Management and other connected fields. Specifically, this book contains applications of such instruments as, among others, Fuzzy Set Qualitative Comparative Analysis, Neuro-Fuzzy Methods, the Forgotten Effects Algorithm, Expertons Theory, Fuzzy Markov Chains, Fuzzy Arithmetic, Decision Making with OWA Operators and Pythagorean Aggregation Operators, Fuzzy Pattern Recognition, and Intuitionistic Fuzzy Sets. The papers in this book tackle a wide variety of problems in areas such as strategic management, sustainable decisions by firms and public organisms, tourism management, accounting and auditing, macroeconomic modelling, the evaluation of public organizations and universities, and actuarial modelling. We hope that this book will be useful not only for business managers, public decision-makers, and researchers in the specific fields of business management, finance, and economics but also in the broader areas of soft mathematics in social sciences. Practitioners will find methods and ideas that could be fruitful in current management issues. Scholars will find novel developments that may inspire further applications in the social sciences

    Fuzzy Sets, Fuzzy Logic and Their Applications

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    The present book contains 20 articles collected from amongst the 53 total submitted manuscripts for the Special Issue “Fuzzy Sets, Fuzzy Loigic and Their Applications” of the MDPI journal Mathematics. The articles, which appear in the book in the series in which they were accepted, published in Volumes 7 (2019) and 8 (2020) of the journal, cover a wide range of topics connected to the theory and applications of fuzzy systems and their extensions and generalizations. This range includes, among others, management of the uncertainty in a fuzzy environment; fuzzy assessment methods of human-machine performance; fuzzy graphs; fuzzy topological and convergence spaces; bipolar fuzzy relations; type-2 fuzzy; and intuitionistic, interval-valued, complex, picture, and Pythagorean fuzzy sets, soft sets and algebras, etc. The applications presented are oriented to finance, fuzzy analytic hierarchy, green supply chain industries, smart health practice, and hotel selection. This wide range of topics makes the book interesting for all those working in the wider area of Fuzzy sets and systems and of fuzzy logic and for those who have the proper mathematical background who wish to become familiar with recent advances in fuzzy mathematics, which has entered to almost all sectors of human life and activity

    Optimization for Decision Making II

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    In the current context of the electronic governance of society, both administrations and citizens are demanding the greater participation of all the actors involved in the decision-making process relative to the governance of society. This book presents collective works published in the recent Special Issue (SI) entitled “Optimization for Decision Making II”. These works give an appropriate response to the new challenges raised, the decision-making process can be done by applying different methods and tools, as well as using different objectives. In real-life problems, the formulation of decision-making problems and the application of optimization techniques to support decisions are particularly complex and a wide range of optimization techniques and methodologies are used to minimize risks, improve quality in making decisions or, in general, to solve problems. In addition, a sensitivity or robustness analysis should be done to validate/analyze the influence of uncertainty regarding decision-making. This book brings together a collection of inter-/multi-disciplinary works applied to the optimization of decision making in a coherent manner

    Fuzzy Sets, Fuzzy Logic and Their Applications 2020

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    The present book contains the 24 total articles accepted and published in the Special Issue “Fuzzy Sets, Fuzzy Logic and Their Applications, 2020” of the MDPI Mathematics journal, which covers a wide range of topics connected to the theory and applications of fuzzy sets and systems of fuzzy logic and their extensions/generalizations. These topics include, among others, elements from fuzzy graphs; fuzzy numbers; fuzzy equations; fuzzy linear spaces; intuitionistic fuzzy sets; soft sets; type-2 fuzzy sets, bipolar fuzzy sets, plithogenic sets, fuzzy decision making, fuzzy governance, fuzzy models in mathematics of finance, a philosophical treatise on the connection of the scientific reasoning with fuzzy logic, etc. It is hoped that the book will be interesting and useful for those working in the area of fuzzy sets, fuzzy systems and fuzzy logic, as well as for those with the proper mathematical background and willing to become familiar with recent advances in fuzzy mathematics, which has become prevalent in almost all sectors of the human life and activity
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