排序方式: 共有75条查询结果,搜索用时 170 毫秒
51.
Rafael SuárezVega Dolores R. SantosPeñate Pablo DortaGonzález 《Journal of regional science》2004,44(3):569-588
Abstract. We investigate the ( r ∣ X p )‐medianoid problem for networks. This is a competitive location problem that consists of determining the locations of r facilities belonging to a firm in order to maximize its market share in a space where a competitor is already operating with p facilities. We consider six scenarios resulting from the combination of three customer choice rules (binary, partially binary, and proportional) with two types of services (essential and unessential).
Known discretization results about the existence of a solution for the set of nodes are extended. Some examples and computational experience using heuristic algorithms are presented. 相似文献
Known discretization results about the existence of a solution for the set of nodes are extended. Some examples and computational experience using heuristic algorithms are presented. 相似文献
52.
53.
54.
55.
Rafael de Miguel González Maria Luisa de Lázaro y Torres 《Journal of Geography in Higher Education》2016,40(2):267-283
This article discusses the current state of the geography discipline in Spanish Universities after putting into action the European Higher Education Area. After decades of geography teaching, following theoretical and expository discourse models, the so-called Bologna Process has been a great opportunity to reflect what geography should be taught, how geography should be taught and why geography should be taught. Aspects such as competences, employability, learning methodologies, assessment, Geographical Information Systems domain have been incorporated into the renewal of geography teaching in Spanish higher education, which has contributed to the strengthening of geography in a context of geospatial technologies revolution and public awareness of spatial challenges. 相似文献
56.
In recent years, unemployment protection systems based on individual savings have been instituted in several developing countries. Chile was one of the first to establish such a system, which at the time was widely cited as a model for other countries. This article discusses the particular political context in which the Chilean system was created before examining how it works in terms of coverage and levels of benefits received by unemployed workers. The authors undertake a detailed analysis of the administrative data produced by the system and conclude that the insurance covers only a small proportion of the unemployed, as most workers generally had precarious jobs that did not allow them to contribute to the system consistently. The Chilean case illustrates how difficult it is to establish functioning unemployment insurance in developing countries with precarious labour markets. Based on the interaction between employment characteristics and the conditions imposed by the benefit system, the article assesses the efficacy of the Unemployment Insurance Savings Accounts (UISA) system and analyses whether it can indeed serve as a model for other developing countries. 相似文献
57.
58.
59.
Rafael Major 《Perspectives on Political Science》2013,42(2):63-65
Abstract Cropsey's book, Plato's World, contains his longest and most sustained reflections on a set of Platonic dialogues, but it is not the first work he published on Plato or the last he intended to write. His last collection of essays, On Humanity's Intensive Introspection, shows that in his writings on Plato Cropsey was attempting to answer a broader question: What is philosophy? 相似文献
60.
The expansion of the Neolithic transition in Europe took place gradually from the Near East across the whole continent. At Northern Europe, observations show a slowdown in the speed of the Neolithic front in comparison to other regions of the continent. It has been suggested that the presence of high population densities of hunter-gatherers at the North could have been the main cause for this slowdown. This proposal has recently been described by a mathematical model that takes into account: (i) the resistance opposed by the Mesolithic populations to the advance of Neolithic populations in their territory, and (ii) a limitation on the population growth dynamics due to the competition for space and resources. But these two effects are not equally responsible for the slowdown of the spread. Indeed, here we show that the limitation on the population growth dynamics seems to have been the main cause of the delay of the expansion of farming in Northern Europe. 相似文献