7 resultados para Uniqueness
em Universidad de Alicante
Resumo:
This paper is intended to provide conditions for the stability of the strong uniqueness of the optimal solution of a given linear semi-infinite optimization (LSIO) problem, in the sense of maintaining the strong uniqueness property under sufficiently small perturbations of all the data. We consider LSIO problems such that the family of gradients of all the constraints is unbounded, extending earlier results of Nürnberger for continuous LSIO problems, and of Helbig and Todorov for LSIO problems with bounded set of gradients. To do this we characterize the absolutely (affinely) stable problems, i.e., those LSIO problems whose feasible set (its affine hull, respectively) remains constant under sufficiently small perturbations.
Resumo:
Our main goal is to compute or estimate the calmness modulus of the argmin mapping of linear semi-infinite optimization problems under canonical perturbations, i.e., perturbations of the objective function together with continuous perturbations of the right-hand side of the constraint system (with respect to an index ranging in a compact Hausdorff space). Specifically, we provide a lower bound on the calmness modulus for semi-infinite programs with unique optimal solution which turns out to be the exact modulus when the problem is finitely constrained. The relationship between the calmness of the argmin mapping and the same property for the (sub)level set mapping (with respect to the objective function), for semi-infinite programs and without requiring the uniqueness of the nominal solution, is explored, too, providing an upper bound on the calmness modulus of the argmin mapping. When confined to finitely constrained problems, we also provide a computable upper bound as it only relies on the nominal data and parameters, not involving elements in a neighborhood. Illustrative examples are provided.
Resumo:
Fundamentos: La relación entre inmigración, trabajo y salud constituye uno de los retos más importantes en salud laboral y más concretamente en España por el importante incremento de proporción inmigrante acontecido en el mercado laboral. El objetivo de esta investigación es conocer la relación entre las condiciones de trabajo y sus efectos en la salud de trabajadores inmigrantes en España. Métodos: Revisión bibliográfica de artículos científicos originales en español e inglés Medline y Medes (1998-2012). Se revisaron los textos completos de los artículos incluidos. Resultados: Se incluyeron 20 estudios, 13 con metodología de investigación cuantitativa y 7 cualitativa. Los temas tratados abordaban problemas específicos de salud relacionados con el trabajo (principalmente lesiones por accidente de trabajo), incapacidad laboral y diferencias en condiciones de trabajo y empleo. Los hallazgos de los estudios mostraron mayor incidencia de lesiones por accidentes de trabajo, menores tasas de incapacidad laboral, mayor prevalencia de presentismo laboral, exposición a factores psicosociales y precariedad laboral en la población inmigrante. Conclusiones: A pesar de la singularidad del proceso demográfico migratorio, los problemas de salud y determinantes identificados no difieren de los referenciados en otros países, en otros contextos y en otros momentos.
Resumo:
This paper studies stability properties of linear optimization problems with finitely many variables and an arbitrary number of constraints, when only left hand side coefficients can be perturbed. The coefficients of the constraints are assumed to be continuous functions with respect to an index which ranges on certain compact Hausdorff topological space, and these properties are preserved by the admissible perturbations. More in detail, the paper analyzes the continuity properties of the feasible set, the optimal set and the optimal value, as well as the preservation of desirable properties (boundedness, uniqueness) of the feasible and of the optimal sets, under sufficiently small perturbations.
Resumo:
More than a hundred public air-raid shelters were constructed beneath Alicante during the Spanish Civil war. Their architectural uniqueness and humanitarian purpose render these shelters a tangible testament to our recent history. The Alicante Municipal Archives hold reports written by technicians who inspected the shelters in the 1940s, which were subsequently included in the Special Plan for public shelters in 1953. Half a century later, in 2003, information on the air-raid shelters was included in another Special Plan aimed at protecting Alicante’s archaeological heritage. Thanks to the work of the Municipal Heritage Conservation unit (COPHIAM) and the Special Protection Plan for Urban Archaeology (PEPA), the exact or approximate locations were identified for almost 90% of the shelters known to have existed. This paper describes interventions in two of these architectural spaces using advanced museology techniques. The first concerns air-raid shelter R46, located in the Plaza del Dr. Balmis in the city centre. This was built in 1938, and is rectangular with two entrances. The second is air-raid shelter R31, located in the Plaza Séneca.
Resumo:
Brasília impõe-se como um interessante caso a ser estudado. Distingue-se de todas as demais cidades do Brasil (e talvez do mundo), mas, ainda assim, reflete a quase totalidade das complexas questões que atingem qualquer grande cidade. A análise de seus processos de patrimonialização e de gestão territorial-patrimonial revela riqueza e singularidade históricas, além de revelar contradições e alta complexidade. O presente ensaio, de cunho teórico-exploratório, propõe-se a analisar o Plano de Preservação do Conjunto Urbanístico de Brasília – PPCUB, projeto de Lei Complementar proposto como política pública de proteção do patrimônio urbano, em busca de relações e conexões entre o contexto sociopolítico de construção da cidade ideal, seu desenvolvimento real e sua consagração como Patrimônio Mundial. Apenas por meio da sinergia de interesses e da ação conjunta dos diversos atores/agentes envolvidos na dinâmica urbana será possível transformar a excepcionalidade e o valor universal em acessibilidade territorial e valor local, dois pilares do desenvolvimento.
Resumo:
Studies highlight the importance of corporate social responsibility (CSR) for companies' stakeholders. Consumers, however, are often unaware of such initiatives. Understanding how to effectively communicate socially responsible initiatives is an important challenge for both researchers and managers, who invest considerable resources in CSR initiatives. This study examines consumers' responses to two types of CSR initiatives (environment-related and employee-based) using two types of message appeals (emotional and rational) across two service types (hedonic and utilitarian). Responses provide data on consumers' awareness of CSR initiatives, attitudes toward the company, perceived company uniqueness, emotional response, and attributions of company motives to engage in CSR activities. Rational appeals more effectively communicate environment-related CSR initiatives, whereas emotional appeals more effectively communicate employee-based CSR initiatives. Effects on consumers' attributions of company motives to engage in CSR are significant in both service types. Finally, rational message appeals affect consumers' CSR awareness and emotional responses in utilitarian service.