International transactions in operational research, Jun 29, 2024
This article proposes a multi-objective mixed-integer linear programming model to assist event ma... more This article proposes a multi-objective mixed-integer linear programming model to assist event managers in obtaining and evaluating non-dominated solutions to the problem of selecting a daily lineup of shows and activities for a festival-be it cultural, sports, ceremonial, or any other kind. The model, which is especially adequate for designing festivals with public funding, has five objectives, relating to financial, logistical, and how renowned the festival artists or acts are. It includes support for multiple days, multiple stages, and different types of shows, all subject to constraints imposed by the intrinsic nature of the festival itself. The output of the model is a set of optimized daily lineups for the activities that constitute the festival, each corresponding to a particular compromise between the five objectives. The approach is demonstrated with a case study for a 5-day festival, for which nondominated solutions are derived, presented, and discussed. Results show that the model can provide a good variety of solutions while ensuring persistence of the more desirable shows. The model is a novel decision support tool to assist in designing festival lineups which provide optimal audience experience, a key factor in attracting spectators, tourists, and increasing comeback value.
A multiobjective modeling approach for managing large scale railway infrastructure asset renewal ... more A multiobjective modeling approach for managing large scale railway infrastructure asset renewal is presented. An optimized intervention project schedule is obtained considering operational constraints in a three objectives model: evenly spreading investment throughout multiple years, minimizing total cost, minimizing work start postponements on higher priority railway sections. The MILP model was based on a real world case study; the objectives and constraints specified by an infrastructure management company. Results show that investment spreading greatly influences the other objectives and that total cost fluctuations depend on the overall condition of the railway infrastructure. The model can produce exact efficient solutions in reasonable time, even for very large-sized instances (a test network of similar size to the USA railway network, the largest in the world). The modeling approach is therefore a very useful, practical methodology, for generating optimized solutions and an...
Multiobjective model for optimizing railway infrastructure asset renewal A multiobjective model f... more Multiobjective model for optimizing railway infrastructure asset renewal A multiobjective model for managing railway infrastructure asset renewal is presented. The model aims at optimizing three objectives, while respecting operational constraints: leveling investment throughout multiple years, minimizing total cost, minimizing work start postponements. Its output is an optimized intervention schedule. The model is based on a case-study from a Portuguese infrastructure management company, who specified the objectives and constraints, and reflects management practice on railway infrastructure. Results show that investment leveling greatly influences the other objectives and that total cost fluctuations may range from insignificant to important, depending on infrastructure condition. The results structure is argued to be general and suggests a practical methodology for analyzing trade-offs and selecting a solution for implementation.
Computer-Aided Civil and Infrastructure Engineering, 2016
A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is... more A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is presented, oriented to interventions on their constituent elements, with two upgrade levels possible for each element (partial/full repairs). The model aims at maximizing benefits and minimizing costs, and its novelty is taking into consideration, and combining, the system/element structure, volume discounts, and socioeconomic factors. The model is tested with field data from 229 sidewalks (systems) and compared to two simpler repair policies, of allowing only partial or full repairs. Results show that the efficiency gains are greater in the lower mid-range budget region. The proposed modeling approach is an innovative tool to optimize cost/benefits for the various repair options and analyze the respective trade-offs.
The location of undesirable facilities involves economic, environmental and social impacts. The c... more The location of undesirable facilities involves economic, environmental and social impacts. The costs associated and the rejection of facilities by nearby population are crucial concerns. This paper introduces a Multiobjective Mixed-Integer Linear Programming (MMILP) approach to identify locations and capacities of biogas plants to treat animal waste from dairy farms, and assign each farm to a subset of the opened biogas plants. Three objectives were considered in the mathematical model: minimizing initial investment, operation and maintenance costs; minimizing transportation cost; and minimizing social rejection. The proposed model was applied to the Entre-Douro-e-Minho Region in Portugal. The approach provided as output a set of Pareto optimal solutions, represented by maps using a Geographic Information System, each one achieving a unique combination of economic and social performance.
Assessment methodologies: energy, mobility and other real world application
This paper presents a Multi-criteria Decision Aid assessment of dairy farms sustainability in the... more This paper presents a Multi-criteria Decision Aid assessment of dairy farms sustainability in the Entre Douro e Minho region in Portugal. Sustainability is a multidimensional concept encompassing often conflicting economic, social and environmental points of view, potentially involving various stakeholders and decision makers. Seven environmental and seven socioeconomic criteria were considered, aided by experts from different fields of knowledge. We used the multi-criteria classification method ELECTRE TRI to sort dairy farms into three categories, where socioeconomic and environment viability were studied separately. The results were then combined to summarize the socioeconomic and environmental viability according to four categories: Highly Sustainable, Moderately Sustainable, Marginally Sustainable and Not Sustainable. We used a Geographic Information System for better visualization and analysis of the spatial behavior of the classification obtained.
Technological and Economic Development of Economy, 2015
This paper studies the determinants of software piracy losses along five major macroeconomic dim... more This paper studies the determinants of software piracy losses along five major macroeconomic dimensions: Technological, Educational, Institutional, Access to Information and Labor force. The study was conducted based on a large dataset available from 1995 to 2010 and comprising 81 countries. As for the Technological dimension, more patents by residents increases piracy losses while the effect of R&D is the opposite (decreases piracy losses). In terms of the Educational dimension, the results show that more spending on education increase the piracy losses but, at the same time, more schooling years have the contrary effect. Concerning the Institutional dimension, nations with less corruption have lower piracy levels. Regarding the Access to Information, it seems that access to Internet diminishes the losses while the share of Internet broadband subscriptions has no effect. The results also show that, regarding the Labor dimension, employment in services has a deterrent effect while ...
Handbook of Research methods and Applications in Environmental Studies
Multi-criteria decision analysis (MCDA) is an approach to evaluate alternatives (projects, plans,... more Multi-criteria decision analysis (MCDA) is an approach to evaluate alternatives (projects, plans, candidates, courses of action, etc.) that explicitly accepts more than one evaluation dimension, instead of using a single indicator. This chapter discusses the use of MCDA for assessing environmental performance taking into account multiple evaluation criteria. Additive models are commonly used for their apparent simplicity, but they require a careful interpretation of the parameters involved, namely concerning normalization and weighting. Moreover, it is debatable whether environmental performance assessment should reflect the subjective values of a single decision maker. Therefore, a partial information multi-attribute value model is used that does not require setting exact values for criteria weights. As a case study, this chapter evaluates the environmental performance of a set of Portuguese dairy farms. Five environmental criteria are considered, which have been defined by experts from the problem domain. The VIP Analysis software is used to obtain results for different partial information assumptions. These results may support recommendations in the context of selection, ranking, or classification of problems.
Atas das I Jornadas Lusófonas de Ciências e Tecnologias de Informação Geográfica
Sistema de apoio à decisão espacial para análise do impacte ambiental da dispersão de poluentes a... more Sistema de apoio à decisão espacial para análise do impacte ambiental da dispersão de poluentes atmosféricos
This work addresses the problem of determining the most suitable sites for locating biogas plants... more This work addresses the problem of determining the most suitable sites for locating biogas plants using dairy manure as feedstock, specifically in the Entre-Douro-e-Minho Region in Portugal. A Multicriteria Spatial Decision Support System is developed to tackle this complex multicriteria decision-making problem, involving constraints and many environmental, economic, safety, and social factors. The approach followed combines the use of a Geographic Information System (GIS) to manage and process spatial information with the flexibility of Multicriteria Decision Aid (MCDA) to assess factual information (e.g., soil type, slope, infrastructures) with more subjective information (e.g., expert opinion). The MCDA method used is ELECTRE TRI, an outranking-type method that yields a classification of the possible alternatives. The results of the performed analysis show that the use of ELECTRE TRI is suitable to address real-world problems of land suitability, leading towards a flexible and integrated assessment.
This paper explores the relation between levels of taxation among different types of households i... more This paper explores the relation between levels of taxation among different types of households in the European Union and the levels of software piracy from 1996 to 2010. It extends previous works introducing a large panel data set for the European Union and it´s different regions. We estimate our model using the fixed effect, comparing results from the Euro Area and the Countries that joined EU in 2004 and 2007. Results show that levels of taxation increase the levels of software piracy losses; moreover these results depend on marital status and number of children. The weight of taxation on GDP, namely the taxes on consumption, have a positive effect on piracy losses while the impact of inflation is negative and marginal. Additional to this we also found that the relative importance of these taxes in relation to total taxation can affect this phenomenon. An increase in the weight of capital taxation would decrease software piracy while this effect was opposite when considering the relative importance of consumption taxes.
As devices that used software became available to the masses the problem of software piracy arose... more As devices that used software became available to the masses the problem of software piracy arose. Recent theoretical works modeled the software piracy phenomenon; others tried to empirically explain the determinants that can explain this phenomenon. Empirical literature in the latter case is still in it´s infancy. This chapter reviews the theoretical literature focusing on three major models, those that deal with diffusion models, network externalities and with game theory. It also presents the empirical literature in which we identify eight stylized results that reflect key variables across five macroeconomic dimensions that explain software piracy: Economic, Cultural, Technological, Legal and Educational dimensions.
The assessment of the environmental sustainability of agricultural infrastructures involves the u... more The assessment of the environmental sustainability of agricultural infrastructures involves the use of multiple evaluation criteria and the analysis of geographical information. A Geographic Information System (GIS) is a computer system capable of assembling, storing, analyzing, and displaying geographically referenced information. However, the GIS technology still suffers from several shortcomings due in large part to a lack of capable analytical capacity of supporting spatial decision problems. The most 2 common solution for GIS to evolve into an effective tool for decision support is to couple them with operational research tools and in particular Multicriteria Decision Aid (MCDA). Due to the technological advances in the field of information systems, there is a great need to research how to integrate GIS, MCDA, the Internet, modeling and databases aiming at creating Web Multicriteria Spatial Decision Support Systems (Web MC-SDSS). A Web MC-SDSS methodological framework is proposed for a fully integrated system of GIS and a specific MCDA method-ELECTRE TRI, through the construction of a Macro written in Visual Basic for Applications (VBA) in ArcGIS software. This macro interacts with a Web Algorithm Server for computing MCDA results. The developed Web MC-SDSS, named ELECTRE TRI in ArcGIS, is applied on a case study analysing the environmental sustainability of dairy farms in the Entre-Douro-e-Minho (EDM) Region.
The location of hazardous material incineration facilities is an important problem due to the env... more The location of hazardous material incineration facilities is an important problem due to the environmental, social, and economic impacts that they impose. The costs associated with the facilities and the risks placed on nearby populations are important concerns as are the distributions of these costs and risks. This paper introduces a mixed-integer, multiobjective programming approach to identify the locations and capacities of such facilities. The approach incorporates a Gaussian dispersion model and a multiobjective optimization model in a GIS based interactive decision support system that planners can access via the Internet. The proposed approach is demonstrated via a case study in central Portugal where the national government has decided to locate a large facility for the incineration of hazardous industrial waste. Due to intense local and national opposition, construction of the facility has been delayed. The system has been designed so that it can be used by decision makers with no special training in dispersion modeling, multiobjective programming, or GIS.
This paper builds upon previous work entailing, in a first stage, the development of a geographic... more This paper builds upon previous work entailing, in a first stage, the development of a geographic information system based environmental modelling approach and, in a second stage, the development of a stand-alone, more generic integrated spatial decision support system. The latter system was designed to address general spatial decision problems in a way that enables interactive definition of mathematical models, the spatial entities involved and their attributes. This manuscript focuses primarily on a further development to implement a multicriteria modelling framework supporting sophisticated evaluation and comparison of hypothetical alternative scenarios in the context of spatial decision problems. Typically several conflicting and generally incommensurable criteria are involved, which derive from the multidimensional nature of most of the decision problems. In such circumstances, multicriteria techniques are recommended to be used in the analysis process. Overall, at the very beg...
Fires, earthquakes, floods, acts of terrorism, nuclear accidents and other catastrophes that may ... more Fires, earthquakes, floods, acts of terrorism, nuclear accidents and other catastrophes that may occur in (or affect) urban areas, constitute an important concern for emergency and rescue services, such as fire departments and medical assistance. This paper introduces a multiobjective approach to identify evacuation paths and the location of shelters for urban evacuation planning. Six objectives including risks associated to paths and shelter locations, evacuation path lengths, and the final evacuation time from shelters to, for instance, hospitals, were considered in a mixed integer linear programming model. The proposed approach was tested for a simulated fire situation concerning the historical urban city center of an old European city (Coimbra, Portugal). The modeling approach may also support other emergency situations for which evacuation plans are pertinent. The solutions generated are compared in the objective space via various graphical techniques and represented via color-coded graphics in a Geographic Information System (GIS) where evacuation routes, rescue facilities and the respective building assignments are shown.
Evacuation planning is an important component of emergency preparedness in urban areas. The numbe... more Evacuation planning is an important component of emergency preparedness in urban areas. The number and location of rescue facilities is an important aspect of this planning, as is the identification of primary and secondary evacuation routes for residents to take. This article introduces a multiobjective approach to identify these aspects of evacuation planning. The approach incorporates a multiobjective model into a geographical information systems-based decision support system that planners can access via the Internet. The proposed approach is demonstrated with a case study for the City of Coimbra, Portugal, for evacuation during major fires. Although presented in this context, this approach is applicable to other emergency situations such as earthquakes, floods, and acts of terrorism.
This paper introduces a mixed-integer, bi-objective programming approach to identify the location... more This paper introduces a mixed-integer, bi-objective programming approach to identify the locations and capacities of semi-desirable (or semi-obnoxious) facilities. The first objective minimizes the total investment cost; the second one minimizes the dissatisfaction by incorporating together in the same function "pull" and "push" characteristics of the decision problem (individuals do not want to live too close, but they do not want to be too far, from facilities). The model determines the number of facilities to be opened, the respective capacities, their locations, their respective shares of the total demand, and the population that is assigned to each candidate site opened. The proposed approach was tested with a case study for a particular urban planning problem: the location of sorted waste containers. The complete set of (supported or unsupported) non-inferior solutions, consisting of combinations of multi-compartment containers for the disposal of four types of sorted waste in nineteen candidate sites, and population assignments, was generated. The results obtained for part of the historical center of an old European city (Coimbra, Portugal) show that this approach can be applied to a real-world planning scenario.
As software is central in today's world, the problem of software piracy is of increasing importan... more As software is central in today's world, the problem of software piracy is of increasing importance. It reduces the revenues of firms that develop new software and, therefore, it may hinder innovation and growth. To understand better the causes of this phenomenon this paper presents a survey of the empirical literature regarding software piracy and discusses if the findings are coherent with the theoretical literature. Overall we are able to identify eight stylized facts in five dimensions: the Economic, Cultural, Educational, Technological and Legal. Moreover we argue that most of these findings are coherent with that which the theoretical models imply.
International transactions in operational research, Jun 29, 2024
This article proposes a multi-objective mixed-integer linear programming model to assist event ma... more This article proposes a multi-objective mixed-integer linear programming model to assist event managers in obtaining and evaluating non-dominated solutions to the problem of selecting a daily lineup of shows and activities for a festival-be it cultural, sports, ceremonial, or any other kind. The model, which is especially adequate for designing festivals with public funding, has five objectives, relating to financial, logistical, and how renowned the festival artists or acts are. It includes support for multiple days, multiple stages, and different types of shows, all subject to constraints imposed by the intrinsic nature of the festival itself. The output of the model is a set of optimized daily lineups for the activities that constitute the festival, each corresponding to a particular compromise between the five objectives. The approach is demonstrated with a case study for a 5-day festival, for which nondominated solutions are derived, presented, and discussed. Results show that the model can provide a good variety of solutions while ensuring persistence of the more desirable shows. The model is a novel decision support tool to assist in designing festival lineups which provide optimal audience experience, a key factor in attracting spectators, tourists, and increasing comeback value.
A multiobjective modeling approach for managing large scale railway infrastructure asset renewal ... more A multiobjective modeling approach for managing large scale railway infrastructure asset renewal is presented. An optimized intervention project schedule is obtained considering operational constraints in a three objectives model: evenly spreading investment throughout multiple years, minimizing total cost, minimizing work start postponements on higher priority railway sections. The MILP model was based on a real world case study; the objectives and constraints specified by an infrastructure management company. Results show that investment spreading greatly influences the other objectives and that total cost fluctuations depend on the overall condition of the railway infrastructure. The model can produce exact efficient solutions in reasonable time, even for very large-sized instances (a test network of similar size to the USA railway network, the largest in the world). The modeling approach is therefore a very useful, practical methodology, for generating optimized solutions and an...
Multiobjective model for optimizing railway infrastructure asset renewal A multiobjective model f... more Multiobjective model for optimizing railway infrastructure asset renewal A multiobjective model for managing railway infrastructure asset renewal is presented. The model aims at optimizing three objectives, while respecting operational constraints: leveling investment throughout multiple years, minimizing total cost, minimizing work start postponements. Its output is an optimized intervention schedule. The model is based on a case-study from a Portuguese infrastructure management company, who specified the objectives and constraints, and reflects management practice on railway infrastructure. Results show that investment leveling greatly influences the other objectives and that total cost fluctuations may range from insignificant to important, depending on infrastructure condition. The results structure is argued to be general and suggests a practical methodology for analyzing trade-offs and selecting a solution for implementation.
Computer-Aided Civil and Infrastructure Engineering, 2016
A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is... more A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is presented, oriented to interventions on their constituent elements, with two upgrade levels possible for each element (partial/full repairs). The model aims at maximizing benefits and minimizing costs, and its novelty is taking into consideration, and combining, the system/element structure, volume discounts, and socioeconomic factors. The model is tested with field data from 229 sidewalks (systems) and compared to two simpler repair policies, of allowing only partial or full repairs. Results show that the efficiency gains are greater in the lower mid-range budget region. The proposed modeling approach is an innovative tool to optimize cost/benefits for the various repair options and analyze the respective trade-offs.
The location of undesirable facilities involves economic, environmental and social impacts. The c... more The location of undesirable facilities involves economic, environmental and social impacts. The costs associated and the rejection of facilities by nearby population are crucial concerns. This paper introduces a Multiobjective Mixed-Integer Linear Programming (MMILP) approach to identify locations and capacities of biogas plants to treat animal waste from dairy farms, and assign each farm to a subset of the opened biogas plants. Three objectives were considered in the mathematical model: minimizing initial investment, operation and maintenance costs; minimizing transportation cost; and minimizing social rejection. The proposed model was applied to the Entre-Douro-e-Minho Region in Portugal. The approach provided as output a set of Pareto optimal solutions, represented by maps using a Geographic Information System, each one achieving a unique combination of economic and social performance.
Assessment methodologies: energy, mobility and other real world application
This paper presents a Multi-criteria Decision Aid assessment of dairy farms sustainability in the... more This paper presents a Multi-criteria Decision Aid assessment of dairy farms sustainability in the Entre Douro e Minho region in Portugal. Sustainability is a multidimensional concept encompassing often conflicting economic, social and environmental points of view, potentially involving various stakeholders and decision makers. Seven environmental and seven socioeconomic criteria were considered, aided by experts from different fields of knowledge. We used the multi-criteria classification method ELECTRE TRI to sort dairy farms into three categories, where socioeconomic and environment viability were studied separately. The results were then combined to summarize the socioeconomic and environmental viability according to four categories: Highly Sustainable, Moderately Sustainable, Marginally Sustainable and Not Sustainable. We used a Geographic Information System for better visualization and analysis of the spatial behavior of the classification obtained.
Technological and Economic Development of Economy, 2015
This paper studies the determinants of software piracy losses along five major macroeconomic dim... more This paper studies the determinants of software piracy losses along five major macroeconomic dimensions: Technological, Educational, Institutional, Access to Information and Labor force. The study was conducted based on a large dataset available from 1995 to 2010 and comprising 81 countries. As for the Technological dimension, more patents by residents increases piracy losses while the effect of R&D is the opposite (decreases piracy losses). In terms of the Educational dimension, the results show that more spending on education increase the piracy losses but, at the same time, more schooling years have the contrary effect. Concerning the Institutional dimension, nations with less corruption have lower piracy levels. Regarding the Access to Information, it seems that access to Internet diminishes the losses while the share of Internet broadband subscriptions has no effect. The results also show that, regarding the Labor dimension, employment in services has a deterrent effect while ...
Handbook of Research methods and Applications in Environmental Studies
Multi-criteria decision analysis (MCDA) is an approach to evaluate alternatives (projects, plans,... more Multi-criteria decision analysis (MCDA) is an approach to evaluate alternatives (projects, plans, candidates, courses of action, etc.) that explicitly accepts more than one evaluation dimension, instead of using a single indicator. This chapter discusses the use of MCDA for assessing environmental performance taking into account multiple evaluation criteria. Additive models are commonly used for their apparent simplicity, but they require a careful interpretation of the parameters involved, namely concerning normalization and weighting. Moreover, it is debatable whether environmental performance assessment should reflect the subjective values of a single decision maker. Therefore, a partial information multi-attribute value model is used that does not require setting exact values for criteria weights. As a case study, this chapter evaluates the environmental performance of a set of Portuguese dairy farms. Five environmental criteria are considered, which have been defined by experts from the problem domain. The VIP Analysis software is used to obtain results for different partial information assumptions. These results may support recommendations in the context of selection, ranking, or classification of problems.
Atas das I Jornadas Lusófonas de Ciências e Tecnologias de Informação Geográfica
Sistema de apoio à decisão espacial para análise do impacte ambiental da dispersão de poluentes a... more Sistema de apoio à decisão espacial para análise do impacte ambiental da dispersão de poluentes atmosféricos
This work addresses the problem of determining the most suitable sites for locating biogas plants... more This work addresses the problem of determining the most suitable sites for locating biogas plants using dairy manure as feedstock, specifically in the Entre-Douro-e-Minho Region in Portugal. A Multicriteria Spatial Decision Support System is developed to tackle this complex multicriteria decision-making problem, involving constraints and many environmental, economic, safety, and social factors. The approach followed combines the use of a Geographic Information System (GIS) to manage and process spatial information with the flexibility of Multicriteria Decision Aid (MCDA) to assess factual information (e.g., soil type, slope, infrastructures) with more subjective information (e.g., expert opinion). The MCDA method used is ELECTRE TRI, an outranking-type method that yields a classification of the possible alternatives. The results of the performed analysis show that the use of ELECTRE TRI is suitable to address real-world problems of land suitability, leading towards a flexible and integrated assessment.
This paper explores the relation between levels of taxation among different types of households i... more This paper explores the relation between levels of taxation among different types of households in the European Union and the levels of software piracy from 1996 to 2010. It extends previous works introducing a large panel data set for the European Union and it´s different regions. We estimate our model using the fixed effect, comparing results from the Euro Area and the Countries that joined EU in 2004 and 2007. Results show that levels of taxation increase the levels of software piracy losses; moreover these results depend on marital status and number of children. The weight of taxation on GDP, namely the taxes on consumption, have a positive effect on piracy losses while the impact of inflation is negative and marginal. Additional to this we also found that the relative importance of these taxes in relation to total taxation can affect this phenomenon. An increase in the weight of capital taxation would decrease software piracy while this effect was opposite when considering the relative importance of consumption taxes.
As devices that used software became available to the masses the problem of software piracy arose... more As devices that used software became available to the masses the problem of software piracy arose. Recent theoretical works modeled the software piracy phenomenon; others tried to empirically explain the determinants that can explain this phenomenon. Empirical literature in the latter case is still in it´s infancy. This chapter reviews the theoretical literature focusing on three major models, those that deal with diffusion models, network externalities and with game theory. It also presents the empirical literature in which we identify eight stylized results that reflect key variables across five macroeconomic dimensions that explain software piracy: Economic, Cultural, Technological, Legal and Educational dimensions.
The assessment of the environmental sustainability of agricultural infrastructures involves the u... more The assessment of the environmental sustainability of agricultural infrastructures involves the use of multiple evaluation criteria and the analysis of geographical information. A Geographic Information System (GIS) is a computer system capable of assembling, storing, analyzing, and displaying geographically referenced information. However, the GIS technology still suffers from several shortcomings due in large part to a lack of capable analytical capacity of supporting spatial decision problems. The most 2 common solution for GIS to evolve into an effective tool for decision support is to couple them with operational research tools and in particular Multicriteria Decision Aid (MCDA). Due to the technological advances in the field of information systems, there is a great need to research how to integrate GIS, MCDA, the Internet, modeling and databases aiming at creating Web Multicriteria Spatial Decision Support Systems (Web MC-SDSS). A Web MC-SDSS methodological framework is proposed for a fully integrated system of GIS and a specific MCDA method-ELECTRE TRI, through the construction of a Macro written in Visual Basic for Applications (VBA) in ArcGIS software. This macro interacts with a Web Algorithm Server for computing MCDA results. The developed Web MC-SDSS, named ELECTRE TRI in ArcGIS, is applied on a case study analysing the environmental sustainability of dairy farms in the Entre-Douro-e-Minho (EDM) Region.
The location of hazardous material incineration facilities is an important problem due to the env... more The location of hazardous material incineration facilities is an important problem due to the environmental, social, and economic impacts that they impose. The costs associated with the facilities and the risks placed on nearby populations are important concerns as are the distributions of these costs and risks. This paper introduces a mixed-integer, multiobjective programming approach to identify the locations and capacities of such facilities. The approach incorporates a Gaussian dispersion model and a multiobjective optimization model in a GIS based interactive decision support system that planners can access via the Internet. The proposed approach is demonstrated via a case study in central Portugal where the national government has decided to locate a large facility for the incineration of hazardous industrial waste. Due to intense local and national opposition, construction of the facility has been delayed. The system has been designed so that it can be used by decision makers with no special training in dispersion modeling, multiobjective programming, or GIS.
This paper builds upon previous work entailing, in a first stage, the development of a geographic... more This paper builds upon previous work entailing, in a first stage, the development of a geographic information system based environmental modelling approach and, in a second stage, the development of a stand-alone, more generic integrated spatial decision support system. The latter system was designed to address general spatial decision problems in a way that enables interactive definition of mathematical models, the spatial entities involved and their attributes. This manuscript focuses primarily on a further development to implement a multicriteria modelling framework supporting sophisticated evaluation and comparison of hypothetical alternative scenarios in the context of spatial decision problems. Typically several conflicting and generally incommensurable criteria are involved, which derive from the multidimensional nature of most of the decision problems. In such circumstances, multicriteria techniques are recommended to be used in the analysis process. Overall, at the very beg...
Fires, earthquakes, floods, acts of terrorism, nuclear accidents and other catastrophes that may ... more Fires, earthquakes, floods, acts of terrorism, nuclear accidents and other catastrophes that may occur in (or affect) urban areas, constitute an important concern for emergency and rescue services, such as fire departments and medical assistance. This paper introduces a multiobjective approach to identify evacuation paths and the location of shelters for urban evacuation planning. Six objectives including risks associated to paths and shelter locations, evacuation path lengths, and the final evacuation time from shelters to, for instance, hospitals, were considered in a mixed integer linear programming model. The proposed approach was tested for a simulated fire situation concerning the historical urban city center of an old European city (Coimbra, Portugal). The modeling approach may also support other emergency situations for which evacuation plans are pertinent. The solutions generated are compared in the objective space via various graphical techniques and represented via color-coded graphics in a Geographic Information System (GIS) where evacuation routes, rescue facilities and the respective building assignments are shown.
Evacuation planning is an important component of emergency preparedness in urban areas. The numbe... more Evacuation planning is an important component of emergency preparedness in urban areas. The number and location of rescue facilities is an important aspect of this planning, as is the identification of primary and secondary evacuation routes for residents to take. This article introduces a multiobjective approach to identify these aspects of evacuation planning. The approach incorporates a multiobjective model into a geographical information systems-based decision support system that planners can access via the Internet. The proposed approach is demonstrated with a case study for the City of Coimbra, Portugal, for evacuation during major fires. Although presented in this context, this approach is applicable to other emergency situations such as earthquakes, floods, and acts of terrorism.
This paper introduces a mixed-integer, bi-objective programming approach to identify the location... more This paper introduces a mixed-integer, bi-objective programming approach to identify the locations and capacities of semi-desirable (or semi-obnoxious) facilities. The first objective minimizes the total investment cost; the second one minimizes the dissatisfaction by incorporating together in the same function "pull" and "push" characteristics of the decision problem (individuals do not want to live too close, but they do not want to be too far, from facilities). The model determines the number of facilities to be opened, the respective capacities, their locations, their respective shares of the total demand, and the population that is assigned to each candidate site opened. The proposed approach was tested with a case study for a particular urban planning problem: the location of sorted waste containers. The complete set of (supported or unsupported) non-inferior solutions, consisting of combinations of multi-compartment containers for the disposal of four types of sorted waste in nineteen candidate sites, and population assignments, was generated. The results obtained for part of the historical center of an old European city (Coimbra, Portugal) show that this approach can be applied to a real-world planning scenario.
As software is central in today's world, the problem of software piracy is of increasing importan... more As software is central in today's world, the problem of software piracy is of increasing importance. It reduces the revenues of firms that develop new software and, therefore, it may hinder innovation and growth. To understand better the causes of this phenomenon this paper presents a survey of the empirical literature regarding software piracy and discusses if the findings are coherent with the theoretical literature. Overall we are able to identify eight stylized facts in five dimensions: the Economic, Cultural, Educational, Technological and Legal. Moreover we argue that most of these findings are coherent with that which the theoretical models imply.
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Papers by Luís Alçada