A joint replenishment competitive location problem

Competitive Location Models seek the positions which maximize the market captured by an entrant firm from previously positioned competitors. Nevertheless, strategic location decisions may have a significant impact on inventory and shipment costs in the future affecting the firm’s competitive advantages. In this work we describe a model for the joint replenishment competitive location problem which considers both market capture and replenishment costs in order to choose the firm’s locations. We also present an metaherusitic method to solve it based on the Viswanathan’s (1996) algorithm to solve the Replenishment Problem and an Iterative Local Search Procedure to solve the Location Problem.N/

Positive Mathematical Programming: a Comparison of Different Specification Rules

In this paper, the prescriptive capacity of different types of positive mathematical programming models applied to the Alentejo agricultural sector is analysed. Model results are compared for 2000 and 2004 agricultural price and subsidies scenarios, regarding optimal combination of activities. Thus, it is tested, on one hand, models capacity to reproduce Alentejo agricultural sector behaviour, and by the other hand, their response and adjustment capacities to changes in prices and in agricultural policy.Positive mathematical programming, agricultural supply, Alentejo, Research Methods/ Statistical Methods,

A regret model applied to the maximum coverage location problem with queue discipline

This article discusses issues related to the location and allocation problems where is intended to demonstrate, through the random number generation, the influence of congestion of such systems in the final solutions. It is presented an algorithm that, in addition to the GRASP, incorporates the Regret with the pminmax method to evaluate the heuristic solution obtained in regard to its robustness for different scenarios. To the well know Maximum Coverage Location Problem from Church and Revelle [1] an alternative perspective is added in which the choice behavior of the server does not only depend on the elapsed time from the demand point looking to the center, but also includes the waiting time for service conditioned by a waiting queue.N/

A regret model applied to the facility location problem with limited capacity facilities

This article addresses issues related to location and allocation problems. Herein, we intend to demonstrate the influence of congestion, through the random number generation, of such systems in final solutions. An algorithm is presented which, in addition to the GRASP, incorporates the Regret with the pminmax method to evaluate the heuristic solution obtained with regard to its robustness for different scenarios. Taking as our point of departure the Facility Location Problem proposed by Balinski [27], an alternative perspective is added associating regret values to particular solutions.N/

Portugal and Ireland : mediaval business connections in the Atlantic

Livro de homenagem à professora Maria Bettencourt Pire

A regret model applied to the maximum capture location problem

This article addresses issues related to location and allocation problems. Herein, we intend to demonstrate the influence of congestion, through the random number generation, of such systems in final solutions. An algorithm is presented which, in addition to the GRASP, incorporates the Regret with the pminmax method to evaluate the heuristic solution obtained with regard to its robustness for different scenarios. Taking as our point of departure the Maximum Capture Location Problem proposed by Church and Revelle [1, 26], an alternative perspective is added in which the choice behavior of the server does not depend only on the elapsed time from the demand point looking to the center, but includes also the service waiting time.N/

Os herdeiros do Infante e o governo dos Açores (1460-1485)

Após uma série de estudos que temos vindo a concretizar sobre o Infante D. Henrique e a sua Casa, prosseguimos a nossa investigação acerca da figura e do património de seu sobrinho e afilhado, o Infante D. Fernando, que considerámos sempre como seu continuador, nem tanto na política que o primeiro se propôs desenvolver, mas como o titular de uma Casa de bens e cargos que não morreram com o primeiro. A tendência era — e, por vezes, sucedeu — fazer valer a força da Lei e, consequentemente, recolher à Coroa o que havia sido distribuído e institucionalizado, com objectivos muito concretos. Como vimos, o 2º Duque de Viseu, potencial herdeiro quase universal — se fosse esta figura jurídica possível — do Navegador, só muito recentemente tem vindo a ser alvo de estudos com maior profundidade. Sebastiana Pereira Lopes, na sua tese de Mestrado, foi quem, até hoje, mais dados reuniu sobre esta figura tão relevante do neo-senhorialismo quatrocentista em Portugal, numa sistematização que se impunha há muito dos seus bens móveis e imóveis, homens de sua Casa, actividades políticas, entre o Continente e o Norte de África… caracterizando aquele que António Caetano de Sousa apelidaria, anos atrás, como o “mayor senhor, que nunca houve em Hespanha, que não fosse Rey”. O seu estudo baseou-se numa bibliografia muito actual e diversificada, quer nacional quer estrangeira. [...

Environmental justice: accessibility of urban public green spaces in two European cities

Although it is unanimous that urban green infrastructure is essential to increase the population’s wellbeing, in many developed countries the availability of green spaces is limited or its distribution around the city is uneven. Also, the availability of public green spaces may be directly related with the geographical location of the city. In Europe, Northern and Central European countries tend to have higher amount of public green spaces compared with the Mediterranean countries. It is also recognized that the distribution of public green spaces is related to the location of social classes. This means that some minorities in society, such as the elderly or ethnic minorities, have less access or are deprived of access to green spaces compared to the rest of the population. In addition, the current planning for urban regeneration and renewal of degraded areas, including slums or ghettos redevelopment, creating new high quality recreational public green spaces, result sometimes in projects that enhance the paradox of green gentrification. Aim of this study is to present evidence about environmental justice in the distribution of the public green spaces in both Tartu, Estonia and Faro, Portugal. Quantitative indicators of public green spaces were calculated in each city districts. The accessibility of those spaces was measured using the “walkability” distance and grid methods. The results revealed that there were more availability and accessibility of public green spaces in Tartu than in Faro. Even so, in Tartu there were inequalities between the soviet-era housing block districts, where the majority of Russian inhabitants live, and the rest. Roma communities in Faro were located in districts without access to public green spaces. Availability of public green spaces was varying from 1.22 to 31.44m2/inhabitant in districts of Faro and 1.04 to 164.07m2/inhabitant in districts of Tartu. In both cities 45% of the inhabitants had accessible public green spaces within 500m from the residence, meanwhile after the development of the proposed new green infrastructure will be 68% for the city of Faro and 86% for Tartu.infraestrutura verde urbana é uma rede de espaços verdes, que inclui parques, jardins ou avenidas arborizadas, estrategicamente planeada de modo a promover a continuidade dos fluxos ecológicos na cidade e, por isso, proteger a fragmentação dos habitats e promover a biodiversidade (European Commission, 2013). Por outro lado, esta infraestrutura tem associados diversos serviços ecossistémicos que asseguram a qualidade de vida das populações urbanas. Incluído nos serviços ecossistémicos pode estar a regulação da temperatura do ar e da água e a melhoria da sua qualidade; o fornecimento de recursos de origem vegetal ou animal, por exemplo, alimentos, madeira, algodão ou lã; entre outros. Para além disso, a presença de espaços verdes nas cidades tem contribuído para o aumento da prática de exercício ao ar livre assim como da melhoria da saúde pública e do aumento da socialização entre indivíduos da mesma comunidade (e.g. Maas, Verheij, Groenewegen, Vries, & Spreeuwenberg, 2006; Gill et al., 2008; Hartig et al., 2010; Dai, 2011). Apesar de ser evidente que a relação entre os espaços verdes e o meio urbano é essencial para o aumento da qualidade de vida das populações (Panagopoulos et al., 2016), observa-se que, ainda em muitos países desenvolvidos, a disponibilidade destes espaços verdes é reduzida ou, por outro lado, a sua distribuição ao longo da cidade é desigual. Alguns autores (Fuller & Gaston, 2009; Kabisch, Strohbach, Haase, & Kronenberg, 2016) afirmam que a disponibilidade de espaços verdes na cidade pode estar diretamente relacionada com a localização geográfica da cidade, por exemplo, no caso da Europa, consideram que os países nórdicos têm tendência a ter maior área de espaços verdes na cidade em comparação com os países localizados ao logo do mediterrâneo. Ou ainda, afirmam que a distribuição dos espaços verdes na cidade está relacionada de acordo com a localização das classes sociais (Park & Kwan, 2017). Isto significa que algumas minorias da sociedade, como por exemplo idosos ou minorias étnicas, têm menor acesso ou são desprovidas de acesso aos espaços verdes em comparação com a restante população (Hoffimann, Barros, & Ribeiro, 2017)