Assigning proctors to exams with scatter search

In this paper we present an algorithm to assign proctors to exams. This NP-hard problem is related to the generalized assignment problem with multiple objectives. The problem consists of assigning teaching assistants to proctor final exams at a university. We formulate this problem as a multiobjective integer program (IP) with a preference function and a workload-fairness function. We then consider also a weighted objective that combines both functions. We develop a scatter search procedure and compare its outcome with solutions found by solving the IP model with CPLEX 6.5. Our test problems are real instances from a University in Spain.Multiobjective combinatorial optimization, metaheuristics, scatter search

A community electrification project: combination of microgrids and household systems fed by wind, PV or micro-hydro energies according to micro-scale resource evaluation and social constraints

When electrifying isolated rural communities, usually standardized solutions have been implemented using the same technology at all the points. However these solutions are not always appropriate to the community and its population. This article aims to describe the technical design of the electrification system of the community of Alto Peru (in the region of Cajamarca, Peru), where the adequate technology was used at each area according to micro-scale resource evaluation and the socioeconomic requirements of the population. Specifically four technologies were implemented: wind microgrids in highlands, a micro-hydro power plant in the presence of a waterfall, a PV microgrid in a group of points sheltered from the wind and individual PV systems in scattered points with low wind potential. This project brought electricity to 58 households, a health center, a school, a church, two restaurants and two shops.Peer ReviewedPostprint (author’s final draft

A community small-scale wind generation project in Peru

Electrification systems based on renewable energy have proven to be suitable for providing decentralized electricity to isolated communities. Electricity generated through wind power is one of the technical options available, although infrequently used to date. This article aims to describe the main aspects of technical design, implementation and management of the first small-scale community wind generation project for rural electrification in Peru. This project took place in the community of El Alumbre, in the region of Cajamarca, which is a mountainous area characterized by low to medium wind speeds. This project, implemented by Soluciones Prácticas – Practical Action (Peru), brought electric power to the 33 households (a total of 150 inhabitants) as well as the school and health center of the community.Peer ReviewedPostprint (published version

Análisis comparativo de la tributación empresarial en los países de la zona euro durante el período 2000-2013

Tradicionalmente, algunos países han utilizado el impuesto sobre los beneficios empresariales como una vía para, partiendo de unos tipos relativamente elevados, fomentar determinadas actividades mediante incentivos o bonificaciones fiscales que permitirían reducir considerablemente esta carga fiscal empresarial. En cambio, otros Estados han optado por reducir directamente la tasa de impuestos, sin tener en cuenta los incentivos fiscales, acercando la tributación nominal a la efectiva. Esta investigación pretende analizar las divergencias existentes en la tributación por el impuesto sobre sociedades entre los distintos países de la eurozona para el período 2000-2013, observando las diferencias entre los tipos nominales y efectivos de las empresas cotizadas. De esta manera, se sitúa en el contexto actual la idea de la Comisión Europea debe adoptar un impuesto de sociedades común, y determinar qué países ejercen una mayor presión fiscal sobre los resultados de sus empresas

Ecosystem vulnerability due to urban growth policies. The role of regulatory ecosystem contributions in the land use planning

If we understand regional resilience as the ease with which different regions adapt to overcome externally produced crises, it appears as necessary to protect both ecosystems and its services, considering the position these hold in regional planning. To be able to protect and/or preserve these ecosystems, it is of paramount importance to identify the areas most vulnerable to these concerns. It has been necessary to develop a methodology to identify Ecosystemic Vulnerability associated to ecosystemic service loss, aiming to prevent its degradation by correctly protecting or preserving it through regional planning. This should help to establish pressure-mitigating policies which could result in variations in its resilience ability

The Economic crisis and immigration: Romanian citizens in the ceramic tile district of Castello (Spain)

Between 2001 and 2007 an exceptional number of immigrants arrived in the province of Castelló (Spain), the majority of whom were from Romania, attracted by the plentiful employment prospects offered by a model of production based on the intensive labour requirements of the ceramic tile and construction industries. The effects of the international economic crisis have been particularly serious in the area of Castelló, where employment has fallen by 20% in just three years. Immigrations flows from Romania have fallen, while the number of those leaving has increased, and migration plans have been modified although the size of the immigrant stock has not fallen significantly due to continued family reunification. The differential between the Spanish and Romanian welfare states, the degree of adaptation in the host society and the strategies developed by the immigrant population explain why returning migrant numbers remain moderate and migratory circulation has increased