This page has only limited features, please log in for full access.
Composite indicators are becoming more relevant for evaluating the performance of water companies from a holistic perspective. Some of them are related with economic aspects, and others focus on social and environmental features. Consequently, a multidimensional evaluation is necessary for handling the great amount of information provided by multiple single indicators of a different nature. This paper presents a two-phase approach to evaluate the sustainability of water companies. First, a partial composite indicator for each dimension (social, environmental, economic) is obtained using multi-criteria decision making (MCDM). Then, a global indicator is obtained, in terms of the values reached in the previous stage for every partial indicator, by means an optimization problem rooted in data envelopment analysis (DEA). Our proposal offers the possibility of analyzing the performance of each water company under each dimension that characterizes the concept of sustainability, as well as a joint assessment including all the dimensions, facilitating the decision-making process. We apply it to evaluate the sustainability of 163 Portuguese water companies. The results show the strengths and weaknesses of each unit and serve as a guideline to decision-makers on the aspects for improving the performance of water utilities.
Fátima Pérez; Laura Delgado-Antequera; Trinidad Gómez; Delgado- Antequera. A Two-Phase Method to Assess the Sustainability of Water Companies. Energies 2019, 12, 2638 .
AMA StyleFátima Pérez, Laura Delgado-Antequera, Trinidad Gómez, Delgado- Antequera. A Two-Phase Method to Assess the Sustainability of Water Companies. Energies. 2019; 12 (13):2638.
Chicago/Turabian StyleFátima Pérez; Laura Delgado-Antequera; Trinidad Gómez; Delgado- Antequera. 2019. "A Two-Phase Method to Assess the Sustainability of Water Companies." Energies 12, no. 13: 2638.
Purpose The purpose of this paper is to empirically examine the factors that influence the acceptance and use of mobile casual games. Design/methodology/approach A theoretical model is proposed based on the theory of reasonable action, the uses and gratifications theory, the network externalities (NEs) paradigm and the human–computer interaction literature. An empirical study was conducted through an online survey of mobile casual gamers in Spain, using a convenience sample. The proposed model was tested by an analysis of the collected data through a structural equation model using the partial least squares method. Findings The results indicate that human–mobile game interaction and NEs have a significant indirect impact on intention to play (IP), through utilitarian, hedonic and relational motivations. In addition, the full mediation effect of attitude was found between these constructs and IP, which is a very important determinant of actual use. Originality/value This study is among the few that focuses on users’ acceptance of mobile games apps, the features of which differ significantly from personal computer and console games. It highlights the effects of human–game interaction and NEs on the adoption of mobile casual games. Hence, the study contributes to the theoretical and practical understanding of the factors that lead users to adopt an entertainment mobile application.
Sebastian Molinillo; Francisco Muñoz-Leiva; Fátima Pérez-García. The effects of human-game interaction, network externalities, and motivations on players’ use of mobile casual games. Industrial Management & Data Systems 2018, 118, 1766 -1786.
AMA StyleSebastian Molinillo, Francisco Muñoz-Leiva, Fátima Pérez-García. The effects of human-game interaction, network externalities, and motivations on players’ use of mobile casual games. Industrial Management & Data Systems. 2018; 118 (9):1766-1786.
Chicago/Turabian StyleSebastian Molinillo; Francisco Muñoz-Leiva; Fátima Pérez-García. 2018. "The effects of human-game interaction, network externalities, and motivations on players’ use of mobile casual games." Industrial Management & Data Systems 118, no. 9: 1766-1786.
Fátima Pérez; María Molinos-Senante; Trinidad Gómez; Rafael Caballero; Ramón Sala-Garrido. Dynamic goal programming synthetic indicator: an application for water companies sustainability assessment. Urban Water Journal 2018, 15, 592 -600.
AMA StyleFátima Pérez, María Molinos-Senante, Trinidad Gómez, Rafael Caballero, Ramón Sala-Garrido. Dynamic goal programming synthetic indicator: an application for water companies sustainability assessment. Urban Water Journal. 2018; 15 (6):592-600.
Chicago/Turabian StyleFátima Pérez; María Molinos-Senante; Trinidad Gómez; Rafael Caballero; Ramón Sala-Garrido. 2018. "Dynamic goal programming synthetic indicator: an application for water companies sustainability assessment." Urban Water Journal 15, no. 6: 592-600.
Fatima Perez; Trinidad Gómez; Rafael Caballero; Vicente Liern. Project portfolio selection and planning with fuzzy constraints. Technological Forecasting and Social Change 2018, 131, 117 -129.
AMA StyleFatima Perez, Trinidad Gómez, Rafael Caballero, Vicente Liern. Project portfolio selection and planning with fuzzy constraints. Technological Forecasting and Social Change. 2018; 131 ():117-129.
Chicago/Turabian StyleFatima Perez; Trinidad Gómez; Rafael Caballero; Vicente Liern. 2018. "Project portfolio selection and planning with fuzzy constraints." Technological Forecasting and Social Change 131, no. : 117-129.
Trinidad Gomez; Ana F. Carazo; Fatima Perez; Julian Molina. A SUPPORT TOOL FOR SELECTING AND SCHEDULING PROJECT PORTFOLIOS. Revista Electrónica de Comunicaciones y Trabajos de ASEPUMA 2017, 18, 153 -176.
AMA StyleTrinidad Gomez, Ana F. Carazo, Fatima Perez, Julian Molina. A SUPPORT TOOL FOR SELECTING AND SCHEDULING PROJECT PORTFOLIOS. Revista Electrónica de Comunicaciones y Trabajos de ASEPUMA. 2017; 18 (1):153-176.
Chicago/Turabian StyleTrinidad Gomez; Ana F. Carazo; Fatima Perez; Julian Molina. 2017. "A SUPPORT TOOL FOR SELECTING AND SCHEDULING PROJECT PORTFOLIOS." Revista Electrónica de Comunicaciones y Trabajos de ASEPUMA 18, no. 1: 153-176.
The aim of this paper is to propose a framework in order to solve the real-world waste collection problem in a city of southern Spain modeled as an Asymmetric Vehicle Routing Problem (AVRP) with side constraints and several variations. In this problem, not only are vehicle capacity and temporal constraints considered but multiple trips are also allowed. Furthermore, two objectives will be considered: the minimization of the total distance and the balance of the working day. Finally, in order to select a single solution among all efficient (or nondominated) solutions, an interactive method is designed using reference points.
L. Delgado-Antequera; Fatima Perez; A. G. Hernández-Díaz; A. D. López-Sánchez. An Interactive Biobjective Method for Solving a Waste Collection Problem. Mathematical Problems in Engineering 2016, 2016, 1 -8.
AMA StyleL. Delgado-Antequera, Fatima Perez, A. G. Hernández-Díaz, A. D. López-Sánchez. An Interactive Biobjective Method for Solving a Waste Collection Problem. Mathematical Problems in Engineering. 2016; 2016 ():1-8.
Chicago/Turabian StyleL. Delgado-Antequera; Fatima Perez; A. G. Hernández-Díaz; A. D. López-Sánchez. 2016. "An Interactive Biobjective Method for Solving a Waste Collection Problem." Mathematical Problems in Engineering 2016, no. : 1-8.
María Molinos-Senante; Rui Cunha Marques; Fatima Perez; Trinidad Gómez; Ramón Sala-Garrido; Rafael Caballero. Assessing the sustainability of water companies: A synthetic indicator approach. Ecological Indicators 2016, 61, 577 -587.
AMA StyleMaría Molinos-Senante, Rui Cunha Marques, Fatima Perez, Trinidad Gómez, Ramón Sala-Garrido, Rafael Caballero. Assessing the sustainability of water companies: A synthetic indicator approach. Ecological Indicators. 2016; 61 ():577-587.
Chicago/Turabian StyleMaría Molinos-Senante; Rui Cunha Marques; Fatima Perez; Trinidad Gómez; Ramón Sala-Garrido; Rafael Caballero. 2016. "Assessing the sustainability of water companies: A synthetic indicator approach." Ecological Indicators 61, no. : 577-587.
Our purpose in this paper is to assist decision-makers in the task of selecting project portfolios to satisfy their requirements and guarantee profitable growth. This task usually involves decision-makers having to face multiple objectives and constraints, as well as the uncertainty associated with certain parameters of the problem. Therefore, in this paper, we propose a multiobjective programming model, which includes uncertainty through the use of fuzzy parameters and allows us to represent information not fully known by the decision-makers. The resulting model has been applied to a project portfolio selection process in a public organisation.
Fátima Pérez; Rafael Caballero; Ana F. Carazo; Trinidad Gómez; Vicente Liern. A multiobjective fuzzy model for selecting and planning a project portfolio in a public organisation. International Journal of Engineering Management and Economics 2015, 5, 48 .
AMA StyleFátima Pérez, Rafael Caballero, Ana F. Carazo, Trinidad Gómez, Vicente Liern. A multiobjective fuzzy model for selecting and planning a project portfolio in a public organisation. International Journal of Engineering Management and Economics. 2015; 5 (1/2):48.
Chicago/Turabian StyleFátima Pérez; Rafael Caballero; Ana F. Carazo; Trinidad Gómez; Vicente Liern. 2015. "A multiobjective fuzzy model for selecting and planning a project portfolio in a public organisation." International Journal of Engineering Management and Economics 5, no. 1/2: 48.
Laura Cruz-Reyes; Eduardo Fernandez; Claudia Gomez; Gilberto Rivera; Fatima Perez. Many-Objective Portfolio Optimization of Interdependent Projects with ‘a priori’ Incorporation of Decision-Maker Preferences. Applied Mathematics & Information Sciences 2014, 8, 1517 -1531.
AMA StyleLaura Cruz-Reyes, Eduardo Fernandez, Claudia Gomez, Gilberto Rivera, Fatima Perez. Many-Objective Portfolio Optimization of Interdependent Projects with ‘a priori’ Incorporation of Decision-Maker Preferences. Applied Mathematics & Information Sciences. 2014; 8 (4):1517-1531.
Chicago/Turabian StyleLaura Cruz-Reyes; Eduardo Fernandez; Claudia Gomez; Gilberto Rivera; Fatima Perez. 2014. "Many-Objective Portfolio Optimization of Interdependent Projects with ‘a priori’ Incorporation of Decision-Maker Preferences." Applied Mathematics & Information Sciences 8, no. 4: 1517-1531.
Decision makers usually have to face a budget and other type of constraints when they have to decide which projects are going to be undertaken (to satisfy their requirements and guarantee profitable growth). Our purpose is to assist them in the task of selecting project portfolios. We have approached this problem by proposing a general nonlinear binary multi-objective mathematical model, which takes into account all the most important factors mentioned in the literature related with Project Portfolio Selection and Scheduling. Due to the existence of uncertainty in different aspects involved in the aforementioned decision task, we have also incorporated into the model some fuzzy parameters, which allow us to represent information not fully known by the decision maker/s. The resulting problem is both fuzzy and multiobjective. The results are complemented with graphical tools, which show the usefulness of the proposed model to assist the decision maker/s.
Francisco Jose Santana Perez; Teresa Lorenzo Gomez. Multiobjective project portfolio selection with fuzzy constraints. Annals of Operations Research 2014, 245, 7 -29.
AMA StyleFrancisco Jose Santana Perez, Teresa Lorenzo Gomez. Multiobjective project portfolio selection with fuzzy constraints. Annals of Operations Research. 2014; 245 (1):7-29.
Chicago/Turabian StyleFrancisco Jose Santana Perez; Teresa Lorenzo Gomez. 2014. "Multiobjective project portfolio selection with fuzzy constraints." Annals of Operations Research 245, no. 1: 7-29.
Víctor Pérez; Flor Guerrero; Mercedes González; Fátima Pérez; Rafael Caballero. Composite indicator for the assessment of sustainability: The case of Cuban nature-based tourism destinations. Ecological Indicators 2013, 29, 316 -324.
AMA StyleVíctor Pérez, Flor Guerrero, Mercedes González, Fátima Pérez, Rafael Caballero. Composite indicator for the assessment of sustainability: The case of Cuban nature-based tourism destinations. Ecological Indicators. 2013; 29 ():316-324.
Chicago/Turabian StyleVíctor Pérez; Flor Guerrero; Mercedes González; Fátima Pérez; Rafael Caballero. 2013. "Composite indicator for the assessment of sustainability: The case of Cuban nature-based tourism destinations." Ecological Indicators 29, no. : 316-324.
Beatriz Rodríguez; Julián Molina; Fatima Perez; Rafael Caballero. Interactive design of personalised tourism routes. Tourism Management 2012, 33, 926 -940.
AMA StyleBeatriz Rodríguez, Julián Molina, Fatima Perez, Rafael Caballero. Interactive design of personalised tourism routes. Tourism Management. 2012; 33 (4):926-940.
Chicago/Turabian StyleBeatriz Rodríguez; Julián Molina; Fatima Perez; Rafael Caballero. 2012. "Interactive design of personalised tourism routes." Tourism Management 33, no. 4: 926-940.
Ana F. Carazo; Ignacio Contreras; Trinidad Gómez; Fátima Pérez. A project portfolio selection problem in a group decision-making context. Journal of Industrial & Management Optimization 2012, 8, 243 -261.
AMA StyleAna F. Carazo, Ignacio Contreras, Trinidad Gómez, Fátima Pérez. A project portfolio selection problem in a group decision-making context. Journal of Industrial & Management Optimization. 2012; 8 (1):243-261.
Chicago/Turabian StyleAna F. Carazo; Ignacio Contreras; Trinidad Gómez; Fátima Pérez. 2012. "A project portfolio selection problem in a group decision-making context." Journal of Industrial & Management Optimization 8, no. 1: 243-261.
This paper proposes a methodology for obtaining a synthetic indicator to facilitate decision making in practical situations. It is based on goals provided by the users, which will be included in a synthetic indicator by a goal-programming approach. This methodology facilitates interpreting the values of the synthetic indicator, and thus helps in the decision-making process. We not only formulate these indicators, but also analyze their properties and apply them to the analysis of a complex concept, sustainable tourism. We use this methodology to study the case of coastal areas of Andalusia (Spain), attempting to identify the main characteristics of the different elements, their weakness and strengths.
Francisco J. Blancas; Rafael Caballero; Mercedes González; Mercedes González Lozano; Fátima Pérez. Goal programming synthetic indicators: An application for sustainable tourism in Andalusian coastal counties. Ecological Economics 2010, 69, 2158 -2172.
AMA StyleFrancisco J. Blancas, Rafael Caballero, Mercedes González, Mercedes González Lozano, Fátima Pérez. Goal programming synthetic indicators: An application for sustainable tourism in Andalusian coastal counties. Ecological Economics. 2010; 69 (11):2158-2172.
Chicago/Turabian StyleFrancisco J. Blancas; Rafael Caballero; Mercedes González; Mercedes González Lozano; Fátima Pérez. 2010. "Goal programming synthetic indicators: An application for sustainable tourism in Andalusian coastal counties." Ecological Economics 69, no. 11: 2158-2172.
This paper introduces an indicator system to evaluate sustainability in established coastal tourism destinations, applying the recommendations and definitions of the World Tourism Organization (WTO). We also develop a new synthetic indicator to simplify the measurement of sustainability and facilitate the comparative analysis of destination ranking. This measurement was obtained by applying a procedure to reduce the number of subjective decisions made by the analyst, using a novel two-stage aggregation methodology based on principal component analysis and on the distance to a reference point. The synthetic indicator obtained was applied to Spanish coastal destinations, and the results serve as a guideline for tourism planning. The conclusions of this research can be extrapolated to the study of other tourism destinations.
Francisco Javier Blancas; Mercedes González; Mercedes González Lozano; Fatima Perez. The assessment of sustainable tourism: Application to Spanish coastal destinations. Ecological Indicators 2010, 10, 484 -492.
AMA StyleFrancisco Javier Blancas, Mercedes González, Mercedes González Lozano, Fatima Perez. The assessment of sustainable tourism: Application to Spanish coastal destinations. Ecological Indicators. 2010; 10 (2):484-492.
Chicago/Turabian StyleFrancisco Javier Blancas; Mercedes González; Mercedes González Lozano; Fatima Perez. 2010. "The assessment of sustainable tourism: Application to Spanish coastal destinations." Ecological Indicators 10, no. 2: 484-492.
Journal of the Operational Research Society (JORS) is the world's longest established OR journal and an official journal of The OR Society. It is the aim of the Journal to present papers which are relevant to practitioners, researchers, teachers, students and consumers of operational research, and which cover the theory, practice, history or methodology of OR.
M Laguna; J Molina; Fatima Perez; R Caballero; Alfredo G. Hernández-Díaz. The challenge of optimizing expensive black boxes: a scatter search/rough set theory approach. Journal of the Operational Research Society 2010, 61, 53 -67.
AMA StyleM Laguna, J Molina, Fatima Perez, R Caballero, Alfredo G. Hernández-Díaz. The challenge of optimizing expensive black boxes: a scatter search/rough set theory approach. Journal of the Operational Research Society. 2010; 61 (1):53-67.
Chicago/Turabian StyleM Laguna; J Molina; Fatima Perez; R Caballero; Alfredo G. Hernández-Díaz. 2010. "The challenge of optimizing expensive black boxes: a scatter search/rough set theory approach." Journal of the Operational Research Society 61, no. 1: 53-67.
In the field of single-objective optimization, hybrid variants of gradient based methods and evolutionary algorithms have been shown to performance better than the pure evolutionary method. This same idea has been used with Evolutionary Multiobjective Optimization (EMO), obtaining also very promising results. In most of the cases, gradient information is used as part of the mutation operator, in order to move every generated point to the exact Pareto front. This means that gradient information is used along the whole process, and then consumes computational resources also along the whole process. On the other hand, in our approach we will use gradient information only at the beginning of the process, and will show that quality of the results is not decreased while computational cost is. We will use a steepest descent method to generate some efficient points to be used to seed an EMO method. The main goal will be generating some efficient points in the exact front using the less evaluations as possible, and let the EMO method use these points to spread along the whole Pareto front. In our approach, we will solve box-constrained continuous problems, gradients will be approximated using quadratic regressions and the EMO method will be based on Rough Sets theory Hernandez-Diaz et al. (Parallel Problem Solving from Nature (PPSN IX) 9th International Conference, 2006).
Alfredo G. Hernandez-Diaz; Carlos Coello Coello; Fatima Perez; Rafael Caballero; Julian Molina. Using a Gradient Based Method to Seed an EMO Algorithm. Multiple Criteria Decision Making 2009, 327 -337.
AMA StyleAlfredo G. Hernandez-Diaz, Carlos Coello Coello, Fatima Perez, Rafael Caballero, Julian Molina. Using a Gradient Based Method to Seed an EMO Algorithm. Multiple Criteria Decision Making. 2009; ():327-337.
Chicago/Turabian StyleAlfredo G. Hernandez-Diaz; Carlos Coello Coello; Fatima Perez; Rafael Caballero; Julian Molina. 2009. "Using a Gradient Based Method to Seed an EMO Algorithm." Multiple Criteria Decision Making , no. : 327-337.
In the field of single-objective optimization, hybrid variants of gradient-based methods and evolutionary algorithms have been shown to perform better than an evolutionary method by itself. This same idea has been recently used in Evolutionary Multiobjective Optimization (EMO), obtaining also very promising results. In most cases, gradient information is used along the whole process, which involves a high computational cost, mainly related to the computation of the step lengths required. In contrast, in this paper we propose the use of gradient information only at the beginning of the search process. We will show that this sort of scheme maintains results of good quality while considerably decreasing the computational cost. In our work, we adopt a steepest descent method to generate some nondominated points which are then used to seed the initial population of a multi-objective evolutionary algorithm (MOEA), which will spread them along the Pareto front. The MOEA adopted in our case is the NSGA-II, which is representative of the state-of-the-art in the area. To validate our proposal, we adopt box-constrained continuous problems (the ZDT test suite). The gradients required are approximated using quadratic regressions. Our proposed approach performs a total of 2000 objective function evaluations, which is much lower than the number of evaluations normally adopted with the ZDT test suite in the specialized literature. Our results are compared with respect to the ldquopurerdquo NSGA-II (i.e., without using gradient-based information) so that the potential benefit of these initial solutions fed into the population can be properly assessed.
Alfredo G. Hernandez-Diaz; Carlos Coello Coello; Fátima Pérez; Rafael Caballero; Julian Molina; Luis V. Santana-Quintero. Seeding the initial population of a multi-objective evolutionary algorithm using gradient-based information. 2008 IEEE Congress on Evolutionary Computation (IEEE World Congress on Computational Intelligence) 2008, 1617 -1624.
AMA StyleAlfredo G. Hernandez-Diaz, Carlos Coello Coello, Fátima Pérez, Rafael Caballero, Julian Molina, Luis V. Santana-Quintero. Seeding the initial population of a multi-objective evolutionary algorithm using gradient-based information. 2008 IEEE Congress on Evolutionary Computation (IEEE World Congress on Computational Intelligence). 2008; ():1617-1624.
Chicago/Turabian StyleAlfredo G. Hernandez-Diaz; Carlos Coello Coello; Fátima Pérez; Rafael Caballero; Julian Molina; Luis V. Santana-Quintero. 2008. "Seeding the initial population of a multi-objective evolutionary algorithm using gradient-based information." 2008 IEEE Congress on Evolutionary Computation (IEEE World Congress on Computational Intelligence) , no. : 1617-1624.
Recent works have shown how hybrid variants of gradient-based methods and evolutionary algorithms perform better than a pure evolutionary method both for single-objective and multiobjective optimization. This same idea has been used with Evolutionary Multiobjective Optimization (EMO), obtaining also very promising results. In most cases, gradient information is used as part of the mutation operator (and only for unconstrained MOPs), in order to move every generated point to the exact Pareto front. In our approach, we use the Karush-Kuhn-Tucker optimality condition for constrained optimization problems to combine the information provided by the gradient vector of each objective function and the gradient vectors of constraint functions to obtain a feasible movement direction in those points near the border. In our approach, gradients of the objective functions will be approximated using quadratic regressions, trying to avoid local optima. The proposed algorithm is able to converge on several nonlinear constrained multiobjective optimization problems obtained from a benchmark, consuming few objective function evaluations (between 150 and 1000). Our results indicate that our proposed scheme may produce a significant reduction in the computational cost, while producing results of good quality, when it is incorporated into a hybrid MOEA or when it is used to seed an EMO algorithm.
Alfredo G. Hernandez-Diaz; Carlos Coello Coello; Luis V. Santana-Quintero; Fatima Perez; Julian Molina; Rafael Caballero. On the Use of Projected Gradients for Constrained Multiobjective Optimization Problems. Computer Vision 2008, 712 -721.
AMA StyleAlfredo G. Hernandez-Diaz, Carlos Coello Coello, Luis V. Santana-Quintero, Fatima Perez, Julian Molina, Rafael Caballero. On the Use of Projected Gradients for Constrained Multiobjective Optimization Problems. Computer Vision. 2008; ():712-721.
Chicago/Turabian StyleAlfredo G. Hernandez-Diaz; Carlos Coello Coello; Luis V. Santana-Quintero; Fatima Perez; Julian Molina; Rafael Caballero. 2008. "On the Use of Projected Gradients for Constrained Multiobjective Optimization Problems." Computer Vision , no. : 712-721.