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In decision making environments under uncertainty, assessments are frequently expressed in linguistic terms. When people express their opinions using linguistic terms, the meanings ascribed to these terms may not always align. This phenomenon is captured by the concept of a linguistic perceptual map, which draws from the established lattice of hesitant fuzzy linguistic term sets. Each individual or group of people (referred to as a ’profile’) possesses their own distinct perceptual map. By projecting and aggregating the opinions of these individuals or groups onto a common perceptual map, an average opinion and a level of consensus are derived. This paper extensively studies the mathematical properties of the projection function. We prove that it is a monomorphism between lattices, preserving crucial order relations. Additionally, we progress beyond existing research by introducing an interpretation function. This function facilitates the translation of the aggregated result (referred to as the ’centroid’) from the common perceptual map to each individual’s perceptual map. The properties of the interpretation function are also subject to analysis, demonstrating its role in preserving previous order relations, despite not being a morphism. To illustrate the practicality of these concepts, we propose a methodology that we apply to a real-world case study involving data in the form of ratings from the Amazon books platform. The results obtained highlight that utilizing distinct perceptual maps for each user profile statistically enhances the degree of consensus compared to scenarios where perceptual maps are not differentiated., This research has been partially supported by the PERCEPTIONS Research Project (PID2020-114247GB-I00), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Preprint

In this study, we propose a methodology using hesitant fuzzy linguistic term sets to aggregate rating values. The main idea is to define an integrated methodology for collaborative platforms involving individuals that use the same set of linguistic terms with different semantics. The objective is to fuse the opinions of different profiles of reviewers or customers when assessing an alternative. The proposed approach allows considering previous assessments to give personalized meaning to a set of linguistic terms. To this end, the concepts of linguistic perceptual maps and projections among perceptual maps are introduced to model and aggregate reviewers’ different profiles. Finally, we compute a measure of consensus to capture the agreement among reviewers’ opinions. All these concepts are applied in a real case example of rating books from Amazon to demonstrate the potential of the methodology in facilitating the evaluation and comparison of different alternatives. Using our methodology, the degree of consensus among customers can be used to rate in a more precise way the books before recommendation., This research has been partially supported by the PERCEPTIONS Research Project (PID2020-114247GB-I00), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Postprint (published version)

The concept of perceptual map is introduced in this paper to capture the semantics of linguistic assessments of an individual in a qualitative reasoning scenario, concretely in hesitant fuzzy linguistic term sets. In addition, the projected perceptual map is considered to provide a space to aggregate different perceptual maps. Qualitative distances and measures of centrality and agreement or consensus are revised based on this projected perceptual map., This research has been partially supported by the PERCEPTIONS R. P. (PID2020-114247GB-I00), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Postprint (published version)

The final publication is available at Springer via http://dx.doi.org/10.1007/s10479-017-2590-4, This paper considers the problem of finding suitable sites for wind farms in a region of Catalonia (Spain). The evaluation criteria are structured into a hierarchy that identifies several intermediate sub-goals dealing with different points of view. Therefore, the recent ELECTRE-III-H hierarchical multi-criteria analysis method is proposed as a good solution to help decision-makers. This method establishes an order among the set of possible sites for the wind farms for each sub-goal. ELECTRE-III-H aggregates these orders into an overall order using different parameters. The procedure is based on the construction and exploitation of a pairwise outranking relation, following the principles of concordance (i.e. majority rule) and discordance (i.e. respect for the minority opinions). This paper makes two main contributions. First, it contributes to the ELECTRE-III-H method by studying its mathematical properties for the construction of outranking relations. Second, the case study is solved and its results show that we can effectively represent and manage the overall influence of the various criteria on the global result at different levels of the hierarchy. The paper compares different scenarios with strict, normal, and optimistic preference, indifference and veto thresholds. Results show that the best site differs for technical, economic, environmental, and social intermediate criteria. Therefore, the best overall solution changes depending on the preference and veto thresholds fixed at the intermediate level of the hierarchy., Peer Reviewed, Postprint (author's final draft)

Understanding different perceptions of human being when using linguistic terms is a crucial issue in human-machine interaction. In this paper, we propose the concept of perceptual maps to model human opinions in a group decision-making context. The proposed approach considers a multi-granular structure using unbalanced hesitant linguistic term sets. An illustrative case is presented in the location decisions made by multinationals enterprises of the energy sector within the European smart city context., This research was supported partly by the INVITE research project (TIN2016- 80049-C2-1-R and TIN2016-80049-C2-2-R), funded by the Spanish Ministry of Science and Information Technology and the European Union Horizon 2020 Research and Innovation Programme, under the grant agreement No 731297., Postprint (published version)

Multiple-criteria or multiple-attribute group decision-making is a sub-field of operations research that seek to find a common and representative solution given the preferences elicited by a pre-defined group, over a set of alternatives and with respect to a set of coherent criteria (or attributes). Recently, the modelling of natural language in these processes has captured the attention of many researchers. Most of the evaluations in a group-decision making context are inherently imprecise, incomplete or vague, and therefore, experts feel more comfortable using their language rather than numerical values. The use of hesitant fuzzy linguistic term sets is one of the recent tools that enables the modelling of linguistic assessments in multiple-criteria decision-making. Nonetheless, advances in hesitant linguistic multi-attribute group decision making require the development of structures flexible enough to deal with unbalanced and multi-granular linguistic information. More tools are needed in order to really grasp the differences in the qualitative reasoning processes of each individual. This thesis, firstly, introduces a perceptual-based distance able to capture differences between unbalanced linguistic assessments, which is based on a lattice structure of hesitant fuzzy linguistic terms. Secondly, this distance is used to define a perceptual-based centroid or central opinion which, in turn, is used to define a consensus measure or degree of agreement within the group. Thirdly, with the aim to deal with multi-perceptual group decision-making contexts, where each decision maker has its own qualitative reasoning approach, a perceptual-based transformation function and a projected algebraic structure are defined. The developed tools can deal with different multi-granularity linguistic environments. Two applications are presented to demonstrate the utility, relevancy and feasibility of the methods. On the one hand, a specific perceptual-based classification and ranking, El multiple-criteria o bé multi-attributte group decision-making (MCGDM / MAGDM) és una branca del camp de OR (operations research) l'objectiu del qual és buscar solucions comunes i representatives donades unes preferències d'un grup d'experts definit, sobre un conjunt d'alternatives i en relació a un conjunt coherent de criteris o atributs. L'objectiu d'aquesta tesis és contribuir específicament en l'àrea lingüística de MCGDM / MAGDM millorant les metodologies i marcs matemàtics existents amb l'objectiu de poder modelar qualsevol tipus de situació de presa de decisions en grup que impliqui multi-granularitat i raonament qualitatiu molt heterogeni entre el grup (ús d'etiquetes lingüístiques no balancejades). En concret, la tesis es basa en l'ús de l'eina dels hesitant fuzzy lingüístic term sets (HFLTSs) que fou introduïda per Rodriguez et al (2012) amb l'objectiu de permetre als experts poder donar opinions i preferències lingüístiques usant el seu llenguatge habitual (i no, números) capturant també la incertesa, ambigüitat i manca d'informació característica en aquest tipus de decisions. La majoria d'estructures matemàtiques existents basades en l'ús de HFLTSs en problemes de MCGDM/MAGDM fan la hipòtesis que tots els experts han d'expressar-se usant el mateix set d'etiquetes lingüístiques i/o bé el pes que cada expert dona a cadascuna de les etiquetes ha de ser el mateix. Aquests estructures no són suficientment flexibles per modelar situacions de GDM de multi-granularitat que també incloguin diversitat de raonament qualitatiu amb etiquetes lingüístiques no balancejades de forma simultània. En primer lloc, la present tesis desenvolupa un nou concepte, el perceptual-map, definit sobre l'estructura algebraica de HFLTSs no balancejats i introdueix una nova distància basada en aquesta mètrica. Aquesta distància és utilitzada per definir un centroide (opinió central) i una mesura de consens per a qualsevol situació de MAGDM que necessiti de l'ús d'un set d'etiquetes lin, Postprint (published version)

Advances in multi-attribute group decision making require the development of structures flexible enough to deal with unbalanced and multi-granular linguistic information. New distances between linguistic terms are needed to aggregate opinions and measure consensus among decision makers with different profiles. In this paper, firstly, based on the lattice structure of hesitant fuzzy linguistic terms sets, a perceptual-based distance able to capture differences between unbalanced linguistic assessments is developed. Secondly, a projected algebraic structure is defined to deal with multiperceptual group decision-making contexts where each decision maker has its own qualitative reasoning approach. To this end, a methodology to aggregate unbalanced linguistic information based on different perceptual maps is developed. This methodology can also deal with different multi-granularity linguistic environments. Finally, through an illustrative example based on real data provided by the Andorra Government in a pilot test, the proposed framework is applied to classify and rank a set of secondary students according to their degree of entrepreneurial competency., Peer Reviewed, Postprint (published version)

Becoming a smart city is one of the top priorities in the urban agenda of many European cities. Among the various strategies in the transition path, local governments seek to bring innovation to their cities by encouraging multinational enterprises to deploy their green energy services and products in their municipalities. Knowing how to attract these enterprises implies that political leaders understand the multi-criteria decision problem that the energy sector enterprises face when deciding whether to expand to one city or another. To this end, the purpose of this study is to design a new manageable and controllable framework oriented to European cities’ public managers, based on the assessment of criteria and sub-criteria governing the strategic location decision made by these enterprises. A decision support framework is developed based on the AHP technique combined with an extended version of the hesitant fuzzy linguistic TOPSIS method. The main results indicate the higher relative importance of government policies, such as degree of transparency or bureaucracy level, as compared to market conditions or economic aspects of the city’s host country. These results can be great assets to current European leaders, they show the feasibility of the method and open up the possibility to replicate the proposed framework to other sectors or geographical areas., The authors acknowledge the support from the European Union “Horizon 2020 Research and Innovation Programme” under the grant agreements No 731297. Also, this research has been partially supported by the INVITE Research Project (TIN2016-80049-C2-1-R and TIN2016-80049-C2-2-R (AEI/FEDER, UE)), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Postprint (published version)

People have come to refer to reviews for valuable information on products before making a purchase. Digesting relevant opinions regarding a product by reading all the reviews is challenging. An automated methodology which aggregates opinions across all the reviews for a single product to help differentiate any two products having the same overall rating is defined. In order to facilitate this process, rating values, which capture the overall satisfaction, and written reviews, which contain the sentiment of the experience with a product, are fused together. In this manner, each reviewer’s opinion is expressed as an interval rating by means of hesitant fuzzy linguistic term sets. These new expressions of opinion are then aggregated and expressed in terms of a central opinion and degree of consensus representing the agreement among the sentiment of the reviewers for an individual product. A real case example based on 2506 TripAdvisor reviews of hotels in Rome during 2017 is provided. The efficiency of the proposed methodology when discriminating between two hotels is compared with the TripAdvisor rating and median of reviews. The proposed methodology obtains significant differentiation between product rankings., This research has been partially supported by the Secretary of Universities and Research of the Department of Enterprise and Knowledge of the Generalitat de Catalunya (2017 DI 086) and by the INVITE Research Project (TIN2016-80049-C2-1-R and TIN2016-80049-C2-2-R (AEI/FEDER, UE)), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Postprint (author's final draft)

Vies Braves (Sea Swimming Lanes) is a pioneer company in designing, promoting, and revitalizing open water and marine itineraries which are protected by buoys, and dedicated to health, leisure, educa- tional and environmental protection activities. The management team's strategic priority is the implementation of new Vies Braves in new coastal locations. In this paper, we propose a fuzzy decision-aiding ap- proach, using hesitant linguistic term sets to study the viability of new potential coastal locations. The proposed approach considers main eco- nomic, political, environmental and social criteria to nd similarities between each new alternative and existing ones., This research was supported partly by the INVITE research project (TIN201680049-C2-1-R and TIN2016-80049-C2-2-R), funded by the Spanish Ministry of Economy and Competitiveness. In addition, the authors gratefully acknowledge the encouraging support of Mr. Miquel Sunyer, CEO of Vies Braves., Peer Reviewed, Postprint (author's final draft)

When searching for recommendations online, users are often presented with similar items all having the same ratings. It is left to the user to discern which rated item is best from other information. In order to facilitate this process, we propose a new methodology to associate a measure of consensus to the ratings derived from a group of reviewers. The opinion of reviewers are considered not only from rating values but from written reviews. This allows us to express reviewer opinions as interval ratings by means of hesitant fuzzy linguistic term sets and compute a consensus. A real case example is provided to show the potential of the proposed methodology. The example provided is based on 966 TripAdvisor reviews of the twenty most reviewed hotels during 2017 in Rome at the time the data was taken. The consensus measure allows us to better understand hotel reviews., This research has been partially supported by the Secretary of Universities and Research of the Department of Enterprise and Knowledge of the Generalitat de Catalunya (2017 DI 086) and by the INVITE Research Project (TIN2016- 80049-C2-1-R and TIN2016-80049-C2-2-R (AEI/FEDER, UE)), funded by the Spanish Ministry of Science and Information Technology., Peer Reviewed, Postprint (published version)

Creating, designing and adjusting products are essential decision processes underlying creative industries, such as painting, perfume, food and beverage industries. These processes require the participation and continuous supervision of professionals with highly-developed expert sensory abilities. Training of these experts is very complex due to the difficulty of transmitting intuitive knowledge obtained from perception. A new methodology for capturing this sensory expert knowledge that relies on a machine learning tool, previously trained with 'state-action’ type patterns, jointly with an actions generator module, is proposed in this work. The method is based on a closed loop architecture together with the decomposition of complex sensory knowledge into basic elements capable of being handled by standard machine learning systems. A real case application to color-adjustment in the automotive paint manufacturing industry is presented showing the potential benefits of the method., This research has been partially supported by the INVITE Research Project (TIN2016-80049-C2-1-R and TIN2016-80049-C2-2-R(AEI/FEDER, UE)), funded by the Spanish Ministry of Science and Information Technology. The authors would like to thank the Research and Development Department of PPG Ibérica in Valladolid (Spain) for providing the research facilities used in this study. The authors also wish to gratefully acknowledge the encouraging given by Mr. Luis Ibáñez, PPG Ibérica’s General Director. We also want to thank the anonymous reviewers for their careful reading of the manuscript and their many insightful comments and suggestions., Peer Reviewed, Postprint (author's final draft)

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Sustainable Tourism on 28 Feb 2018, available online at: https://www.tandfonline.com/doi/full/10.1080/09669582.2018.1433183.", Many destinations are implementing various water management alternatives to diminish the environmental impacts of tourism and increase sustainability. These efforts toward sustainability can be understood as part of corporate social responsibility (CSR) strategies implemented by tourism destinations. This paper is focused on the tourism destination of the Costa Brava (Catalonia, Spain) and proposes a method for selecting a list of influential factors in water management for sustainable tourism destinations by considering stakeholder preferences for technical, economic, social, political, and environmental factors. A new qualitative Delphi technique is used to identify a set of qualitative and quantitative factors by surveying eight stakeholders (six water management experts and two hotel managers). In addition, the study presents the weight for each of the influential factors that decision-makers – water planners, policy-makers, tourism destination managers and hotel managers – can use in assessing water management alternatives. Although research to date has addressed many aspects of responsible tourism, there is little literature on the importance of water management in responsible strategies for tourism destinations. This paper contributes to a more efficient selection of CSR strategies in tourism destinations by proposing a new methodology for identifying key factors for assessing sustainable solutions for water problems., Peer Reviewed, Postprint (author's final draft)

Decision-making is an active field of research. Specifically, in recent times, a lot of contributions have been presented on decision-making under linguistic assessments. To tackle this kind of processes, hesitant fuzzy linguistic term sets have been introduced to grasp the uncertainty inherent in human reasoning when expressing preferences. This thesis introduces an extension of the set of hesitant fuzzy linguistic term sets to capture differences between non-compatible assessments. Based on this extension, a distance between linguistic assessments is defined to quantify differences between several opinions. This distance is used in turn to present a representative opinion from a group in a decision-making process. In addition, different consensus measures are introduced to determine the level of agreement or disagreement within a decision-making group and are used to define a decision maker’s profile to keep track of their dissension with respect to the group as well as their level of hesitancy. Furthermore, with the aim of allowing decision makers to choose the linguistic terms that they feel more comfortable with, the concept of free double hierarchy hesitant fuzzy linguistic term set is developed in this thesis. Finally, a new approach of the TOPSIS methodology for processes in which the assessments are given by means of free double hierarchy hesitant fuzzy information is presented to rank alternatives under these circumstances., Postprint (published version)

Present measures of the degree of agreement in group decision-making using hesitant fuzzy linguistic term sets allow consensus or agreement measurement when decision makers’ assessments involve hesitance. Yet they do not discriminate with different degrees of consensus among situations with discordant or polarized assessments. The visualization of differences among groups for which there is no agreement but different possible levels of disagreement is an important issue in collective decision-making situations. In this paper, we propose new collective and individual consensus measures that explicitly consider the hesitance of the decision makers’ hesitance in giving an opinion and also the gap between non-overlapping assessments, thus allowing the measurement of the polarization present within the group's opinions. In addition, an expert's profile is defined by considering the expert's behavior in previous assessments in group decision-making processes in terms of precision and dissension., Peer Reviewed, Postprint (author's final draft)

Hesitant linguistic term sets have been introduced to capture the human way of reasoning using linguistic expressions involving different levels of precision. In this paper, a lattice structure is provided to the set of hesitant fuzzy linguistic term sets by means of the operations intersection and connected union. In addition, in a group decision making framework, hesitant fuzzy linguistic descriptions are defined to manage situations in which decision makers are assessing different alternatives by means of hesitant fuzzy linguistic term sets. Based on the introduced lattice structure, two distances between hesitant fuzzy linguistic descriptions are defined. These metric structures allow distances between decision makers to be computed. A centroid of the decision making group is proposed for each distance to model group representatives in the considered group decision making framework., Peer Reviewed, Postprint (author's final draft)

This paper proposes a measure of consensus for group decision making in the hesitant fuzzy linguistic term sets framework. An extension of the set of hesitant fuzzy linguistic term sets is considered to capture differences among discordant assessments. The difference between a pair of disjoint assessments is given by a measure that takes into account the gap between them. The proposed measure of consensus is defined using this extension, and, as a result, we obtain more accurate values, i.e., the new measure is able to distinguish among group consensus levels that were indistinguishable according to existing measures of consensus. An illustrative example is provided to show the potential of the proposed consensus degree, the process of its computation and a comparison with an existing approach based on a similarity among decision makers., Peer Reviewed, Postprint (author's final draft)

The final publication is available at Springer via http://dx.doi.org/10.1007/s13762-016-0982-7, Multi-criteria decision-making methods support decision makers in all stages of the decision-making process by providing useful data. However, criteria are not always certain as uncertainty is a feature of the real world. MCDM methods under uncertainty and fuzzy systems are accepted as suitable techniques in conflicting problems that cannot be represented by numerical values, in particular in energy analysis and planning. In this paper, a modified TOPSIS method for multi-criteria group decision-making with qualitative linguistic labels is proposed. This method addresses uncertainty considering different levels of precision. Each decision maker’s judgment on the performance of alternatives with respect to each criterion is expressed by qualitative linguistic labels. The new method takes into account linguistic data provided by the decision makers without any previous aggregation. Decision maker judgments are incorporated into the proposed method to generate a complete ranking of alternatives. An application in energy planning is presented as an illustrative case example in which energy policy alternatives are ranked. Seven energy alternatives under nine criteria were evaluated according to the opinion of three environmental and energy experts. The weights of the criteria are determined by fuzzy AHP, and the alternatives are ranked using qualitative TOPSIS. The proposed approach is compared with a modified fuzzy TOPSIS method, showing the advantages of the proposed approach when dealing with linguistic assessments to model uncertainty and imprecision. Although the new approach requires less cognitive effort to decision makers, it yields similar results., Peer Reviewed, Postprint (author's final draft)

This paper models the assessments of a group of experts when evaluating different magnitudes, features or objects by using linguistic descriptions. A new general representation of linguistic descriptions is provided by unifying ordinal and fuzzy perspectives. Fuzzy qualitative labels are proposed as a generalization of the concept of qualitative labels over a well-ordered set. A lattice structure is established in the set of fuzzy-qualitative labels to enable the introduction of fuzzy-qualitative descriptions as L-fuzzy sets. A theorem is given that characterizes finite fuzzy partitions using fuzzy-qualitative labels, the cores and supports of which are qualitative labels. This theorem leads to a mathematical justification for commonly-used fuzzy partitions of real intervals via trapezoidal fuzzy sets. The information of a fuzzy-qualitative label is defined using a measure of specificity, in order to introduce the entropy of fuzzy-qualitative descriptions. (C) 2016 Elsevier Inc. All rights reserved., Peer Reviewed, Postprint (author's final draft)

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Experimental & Theoretical Artificial Intelligence on 27.04.2015, available online: http://www.tandfonline.com/doi/10.1080/0952813X.2015.1024489, A social multi-criteria evaluation framework for solving a real-case problem of selecting a wind farm location in the regions of Urgell and Conca de Barberá in Catalonia (northeast of Spain) is studied. This paper applies a qualitative multi-criteria decision analysis approach based on linguistic labels assessment able to address uncertainty and deal with different levels of precision. This method is based on qualitative reasoning as an artificial intelligence technique for assessing and ranking multi-attribute alternatives with linguistic labels in order to handle uncertainty. This method is suitable for problems in the social framework such as energy planning which require the construction of a dialogue process among many social actors with high level of complexity and uncertainty. The method is compared with an existing approach, which has been applied previously in the wind farm location problem. This approach, consisting of an outranking method, is based on Condorcet's original method. The results obtained by both approaches are analysed and their performance in the selection of the wind farm location is compared in aggregation procedures. Although results show that both methods conduct to similar alternatives rankings, the study highlights both their advantages and drawbacks., Peer Reviewed, Postprint (author's final draft)

Hesitant fuzzy linguistic term sets were introduced to grasp the uncertainty existing in human reasoning. In this paper, inspired by absolute order-of-magnitude qualitative reasoning techniques, an extension of the set of hesitant fuzzy linguistic term sets is presented to capture differences between non-compatible preferences. In addition, an order relation and two closed operations over this set are also introduced to provide a lattice structure to the extended set of hesitant fuzzy linguistic term sets. Based on this lattice structure a distance between hesitant fuzzy linguistic term sets is defined., Peer Reviewed, Postprint (author's final draft)

This paper offers a new method inspired by classic importance-performance analysis (IPA) that provides a global index of importance versus performance for firms together with a new version of the IPA diagram. The index compares two rankings of the same set of features regarding importance and performance, taking into account under-performing features. The marginal contribution of each feature to the proposed global index defines a set of isocurves that represents an improvement in the IPA diagram. The defined index, together with the new version of the diagram, enables, by means of qualitative reasoning techniques, the assessment of a firm’s overall performance and therefore enhance decision making in the allocation of resources. The proposed method has been applied to a Taiwanese multi-format retailer and managerial perceptions of performance and importance are compared to assess the firm’s overall performance., Peer Reviewed, Postprint (author's final draft)

The final publication is available at Springer via http://dx.doi.org/10.1007/s00500-015-1696-3, Performance measurement is a key issue when a company is designing new strategies to improve resource allocation. This paper offers a new methodology inspired by classic importance-performance analysis (IPA) that provides a global index of importance versus performance for firms. This index compares two rankings of the same set of features regarding importance and performance, taking into account underperforming features. The marginal contribution of each feature to the proposed global index defines a set of iso-curves that represents an improvement in the IPA diagram. The defined index, together with the new version of the diagram, will enable the assessment of a firm's overall performance and, therefore, enhance decision making in the allocation of resources. The proposed methodology has been applied to a Taiwanese multi-format retailer and managerial perceptions of performance and importance are compared to assess the firm's overall performance., Peer Reviewed, Postprint (author's final draft)

Given a finite totally ordered set of linguistic terms, the operations intersection and connected union provide a lattice structure to the set of hesitant fuzzy linguistic term sets. In this framework, hesitant fuzzy linguistic descriptions of a given set of alternatives are considered. A distance between hesitant fuzzy linguistic descriptions is introduced based on the properties of the lattice. This metric structure allows distances between decision makers to be computed. A centroid or group representative is defined in group decision-making processes where decisión makers are assessing different alternatives by means of hesitant fuzzy linguistic term sets., Peer Reviewed, Postprint (author's final draft)

Energy problems are serious problems caused by limited resources and by human activity such as deforestation, water pollution and various other long-term practices that have environmental impact which produces global warming and climate change. These complex problems usually involve multiple conflicting criteria and multiple decision makers. They require the use of multi-criteria decision-making methods to evaluate different types of variables with respect to sustainability factors addressing conflicting economic, technological, social and environmental aspects. These factors, especially social ones, are not always precise, as imprecision and uncertainty are features of the real world. Therefore, in order to provide useful data from experts' assessments, in this thesis a new multi-criteria decision-making method, as a useful tool in energy planning, is presented. This method supports decision makers in all stages of the decision-making process with uncertain values. An exhaustive literature review on multi-criteria decision analysis and energy planning has been conducted in this thesis. First, the in-depth study of criteria and indicators in the energy planning area is presented. Some well-known multi-criteria decision-making methods and their applications are introduced. In these problems, it is often difficult to obtain exact numerical values for some criteria and indicators. In order to overcome this shortcoming, qualitative reasoning techniques integrated with multi-criteria decision-making methods are capable of representing uncertainty, emulating skilled humans, and handling vague situations. This study proposes a Qualitative TOPSIS (Q-TOPSIS) method, which is a new method for ranking multi-criteria alternatives in group decision making. This new method, in its first step, takes into account qualitative data provided by the decision makers' individual linguistic judgments on the performance of alternatives with respect to each criterion, without any previous a, Los problemas de la energía son problemas graves causados por los recursos limitados y las actividades humanas como la deforestación, contaminación del agua y otras prácticas con efectos a largo plazo. Estas prácticas tienen un gran impacto ambiental y dan lugar al efecto invernadero, que ocasiona el calentamiento global y cambio climático. Los problemas complejos implican generalmente múltiples criterios contradictorios y múltiples decisores. Requieren el uso de métodos toma de decisiones multicriterio para evaluar diferentes tipos de variables con respecto a factores de sostenibilidad, incluyendo aspectos conflictivos económicos, tecnológicos, sociales y ambientales. Estos factores, especialmente los sociales, no siempre son precisos, dado que la imprecisión y la incertidumbre son características del mundo real. Por lo tanto, con el fin de proporcionar datos útiles a partir de evaluaciones de expertos, en esta tesis se presenta un nuevo método de toma de decisiones multicriterio, como una herramienta útil en la planificación de la energía. Este método permite a los decisores utilizar valores con imprecisión en todas las etapas de la toma de decisiones. En esta tesis se ha realizado una revisión exhaustiva de la literatura sobre el análisis de la decisión multicriterio y la planificación de la energía. En primer lugar, se presenta el estudio a fondo de los criterios e indicadores en el área de planificación de la energía. Se introducen algunos de los métodos más conocidos de toma de decisiones multicriterio y sus aplicaciones. En estos problemas, a menudo es difícil obtener valores numéricos exactos para algunos criterios e indicadores. Para superar esta deficiencia, la integración de técnicas de razonamiento cualitativo en métodos de decisión multicriterio permite representar la incertidumbre, emular el trabajo de seres humanos cualificados y manejar situaciones vagas. Este estudio propone un método TOPSIS cualitativo (Q-TOPSIS), que es un nuevo método de ranking, Postprint (published version)

This paper proposes a new model of consensus based on linguistic terms to be implemented in Delphi processes. The model of consensus involves qualitative reasoning techniques and is based on the concept of entropy. The proposed model has the ability to reach consensus automatically without the need for either a moderator or a final interaction among panelists. In addition, it permits panelists to answer with different levels of precision depending on their knowledge on each question. The model defined hasbeen used to establish the relevant features for the definition of a type of chronic disease. A real-case application conducted in the Department of Neonatology of Máxima Medical Center in The Netherlands is presented. This application considers the opinions of stakeholders of neonate health-care in order toreach a final consensual definition of chronic pain in neonates., This paper proposes a new model of consensus based on linguistic terms to be implemented in Delphi processes. The model of consensus involves qualitative reasoning techniques and is based on the concept of entropy. The proposed model has the ability to reach consensus automatically without the need for either a mod- erator or a final interaction among panelists. In addition, it permits panelists to answer with different levels of precision depending on their knowledge on each question. The model defined has been used to establish the relevant features for the definition of a type of chronic disease. A real-case application conducted in the Department of Neonatology of M ́ axima Medical Center in The Netherlands is pre- sented. This application considers the opinions of stakeholders of neonate health- care in order to reach a final consensual definition of chronic pain in neonates., Peer Reviewed, Postprint (author’s final draft)

Multi-Criteria Decision Aid (MCDA) methods include various collections of mathematical techniques related to decision support systems in non-deterministic environments to support such applications as facility management, disaster management and urban planning. This paper applies MCDA approaches based on qualitative reasoning techniques with linguistic labels assessment. The aim of this method is ranking multi-attribute alternatives in group decision-making with qualitative labels. Finally this method is applied to a case of urban planning in selection of the less energy consumption project in a geographical area in Catalonia., Peer Reviewed, Postprint (published version)

The concept mapping methodology aims to respond to the non trivial task of conceptualising abstract thoughts by means of a focus group composed by experts from the studied domain. The approach defines a set of general steps that allow experts to lead the generation of ideas, group the ideas in a conceptual map of interrelated concepts using clustering multidimensional scaling and clustering techniques, analysing the quality of the conceptual maps and deciding on a final interpretation. In this sense, this final decision is not trivial because clustering techniques provide a set of potentially conceptual maps so experts must select the one that fits best according to their opinion. For this reason, we present the global index of consensus as an indicator for filtering the most suitable clustering solutions using qualitative reasoning. It promotes the consensus of experts opinions and ensures objectivity in the final interpretation. The index outperforms three of the most well-known clustering validation indexes in a case study focused on the meaning of excellence in the hospitality industry.; This work presents the global index of consensus as an indicator for filtering the most suitable clustering solutions using qualitative reasoning that promotes the consensus of experts' opinions, which is one of the key aspects in the concept mapping methodology. The index outperforms three of the most well-known clustering validation indexes in a case study focused on the meaning of excellence in hospitality. (C) 2015 Elsevier B.V. All rights reserved., Peer Reviewed, Postprint (author's final draft)

Given a finite totally ordered set of linguistic descriptions, the extended set of qualitative labels with different levels of precision L is constructed. In this framework, qualitative descriptions of a given set are L-fuzzy sets. A distance between L-fuzzy sets is introduced based on the properties of the lattice L. An illustrative example in the retail sector applied to assess a firm’s overall performance using perceptions of managers in the firm’s different departments is presented., Given a finite totally ordered set of linguistic descriptions, the extended set of qualitative labels with different levels of precision L is constructed. In this framework, quali- tative descriptions of a given set are L -fuzzy sets. A distance between L -fuzzy sets is introduced based on the properties of the lattice L . An illustrative example in the retail sector applied to assess a firm’s overall performance using perceptions of managers in the firm’s different departments is presented., Peer Reviewed, Postprint (author’s final draft)

A new approach for Delphi processes including a measure of consensus based on linguistic terms is introduced in this paper. The measure of consensus involves qualitative reasoning techniques and is based on the concept of entropy. In the proposed approach, consensus is reached automatically without the need for neither a moderator nor a final interaction among panelists. In addition, it permits panelists to answer with different levels of precision depending on their knowledge on each question. An illustrative example considering the opinions of stake holders in neonate health-care to reach a final consensual definition of chronic pain in neonates is presented., Peer Reviewed, Postprint (published version)

This paper compares two multi-criteria decision making (MCDM) approaches based on linguistic label assessment. The first approach consists of a modified fuzzy TOPSIS methodology introduced by Kaya and Kahraman in 2011. The second approach, introduced by Agell et al. in 2012, is based on qualitative reasoning techniques for ranking multi-attribute alternatives in group decision-making with linguistic labels. Both approaches are applied to a case of assessment and selection of the most suitable types of energy in a geographical area., Peer Reviewed, Postprint (published version)

When a group of experts is involved in the design of a new product as a team, consensus and Group decision making (GDM) techniques able to deal with complex descriptions are required. In addition, individual decisions based on human sensory perception, such as color, smell or taste, are usually qualitative and made under uncertainty. In this paper we consider a methodology based upon qualitative reasoning techniques for representing and synthesizing the information given by a group of experts in order to capture the sensorial aspects of the alternatives. A real application of the proposed GDM method to chocolates design has been conducted throughout 2012 with the Chocolate Chef Oriol Balaguer’s team. We present the results obtained by applying the proposed methodology to aggregate experts’ opinion during a creative session. In this session, some members of Oriol Balaguer’s team tested and evaluated combinations of black chocolate with six different fruits, considered as alternatives, to select the best combination for the design and creation of a new cake., Peer Reviewed, Postprint (published version)

Creation and design of products based on human sensory perceptions, such as color, smell or taste, require the participation of professionals or experts with highly developed sensory abilities. When a group of experts is involved in such creative process as a team, consensus and group decision-making (GDM) techniques able to deal with qualitative descriptions and uncertainty, can be required. In this paper we consider a methodology based upon qualitative reasoning techniques for representing and synthesizing the information given by a group of experts in order to capture the sensorial aspects of the alternatives. A real application of the proposed GDM method to chocolates design has been conducted throughout 2012 with the Chocolate Chef Oriol Balaguer’s team. We present the results obtained by applying the proposed methodology to aggregate experts’ opinion during a creative session. In this session, some members of Oriol Balaguer’s team tested and evaluated combinations of black chocolate with six different fruits, considered as alternatives, to select the best combination for the design and creation of a new cake., Peer Reviewed, Postprint (published version)

This paper presents a methodology for a collaborative recommender system (RS). The methodology is based on the compatibility of groups of users defining their profiles via a qualitative order-ofmagnitude model. The distributive lattice structure of the space of qualitative descriptions is considered in defining the distance between existing users and the RSs new users. An application to movie recommendations is presented to show and compare the efficiency of the proposed methodology., Postprint (published version)

This paper presents the foundation for a new methodology for a collaborative recommender system (RS). This methodology is based on the degree of consensus of a group of users stating their preferences via qualitative orders-of-magnitude. The structure of distributive lattice is considered in defining the distance between users and the RSs new users. This proposed methodology incorporates incomplete or partial knowledge into the recommendation process using qualitative reasoning techniques to obtain consensus of its users for recommendations., Postprint (published version)

Ordinal scales are commonly used in rating and evaluation processes. These processes usually involve group decision making by means of an experts’ committee. In this paper a mathematical framework based on the qualitative model of the absolute orders of magnitude is considered. The entropy of a qualitatively described system is defined in this framework. On the one hand, this enables us to measure the amount of information provided by each evaluator and, on the other hand, the coherence of the evaluation committee. The new approach is capable of managing situations where the assessment given by experts involves different levels of precision. The use of the proposed measures within an automatic system for group decision making will contribute towards avoiding the potential subjectivity caused by conflicts of interests of the evaluators in the group., Postprint (published version)

This paper presents a mathematical framework to assess the consensus found among different evaluators who use ordinal scales in group decision-making and evaluation processes. This framework is developed on the basis of the absolute order-of-magnitude qualitative model through the use of qualitative entropy. As such, we study the algebraic structure induced in the set of qualitative descriptions given by evaluators. Our results demonstrate a weak, partial and semi lattice structure that in some conditions takes the form of a distributive lattice. We then define the entropy of a qualitatively-described system. This enables us, on the one hand, to measure the amount of information provided by each evaluator and, on the other hand, to consider a degree of consensus among the evaluation committee. This new approach is capable of managing situations where the assessment given by experts involves different levels of precision. In addition, when there is no consensus regarding the group decision, an automatic process assesses the effort required to achieve said consensus., Postprint (published version)