排序方式: 共有75条查询结果,搜索用时 15 毫秒
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Indo-Iranian Journal - 相似文献
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Integration Processes in European Research and Development: A Comparative Spatial Interaction Approach Using Project Based Research and Development Networks,Co‐Patent Networks and Co‐Publication Networks
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This study focuses on integration processes in European Research and Development (R&D) by analyzing the spatiotemporal dimension of three different R&D collaboration networks across Europe. The studied networks cover different types of knowledge creation, namely project‐based R&D networks within the European Union (EU) Framework Programmes (FPs), co‐patent networks, and co‐publication networks. Integration in European R&D—one of the main pillars of the EU Science Technology and Innovation policy—refers to the harmonization of fragmented national research systems across Europe and to the free movement of knowledge and researchers. The objective is to describe and compare spatiotemporal patterns at a regional level and to estimate the evolution of separation effects over the time period 1999–2006 that influence the probability of cross‐region collaborations in the distinct networks under consideration. The study adopts a spatial interaction modeling perspective, econometrically specifying a panel generalized linear model relationship, taking into account spatial autocorrelation among flows using eigenfunction spatial filtering methods. The results show that geographical factors are a lower hurdle for R&D collaborations in the FP networks than in co‐patent networks and co‐publication networks. Furthermore, it is shown that the geographical integration is higher in the FP network. 相似文献
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Rafael González‐Val 《Journal of regional science》2010,50(5):952-972
ABSTRACT This paper analyses the evolution of city size distribution in the United States throughout the twentieth century. It tests the validity of two empirical regularities studied in urban economics: Zipf's law (the rank‐size rule), and Gibrat's law, or the law of proportionate growth. The main contribution of this work is the use of a new database with information on all the cities (understood as incorporated places), without size restrictions. Our results enable us to confirm that Gibrat's law holds (weakly), and that Zipf's law holds only if the sample is sufficiently restricted at the top, not for a larger sample. 相似文献
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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
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Martínez Sánchez Rafael M. Vera-Rodríguez Juan Carlos Pérez-Jordà Guillem Moreno-García Marta Bokbot Youssef Peña-Chocarro Leonor 《African Archaeological Review》2021,38(2):251-274
African Archaeological Review - This study focuses on the chronostratigraphic sequence of the Cave of Kaf Taht el-Ghar (Dar Ben Karrich, Tétouan, Morocco) excavated in 2012 in the framework of... 相似文献
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Recent data from the site of Cerro Lampay, a Late Archaic Period compound in central Peru, sheds light on the role of ritual and architectural construction in the emergence of social complexity in the Central Andes. Excavations at this site have provided a detailed documentation of the building process that ended in the entombment of architectural compounds, including a remarkable sequence of construction events preceded by the processing and consumption of foodstuffs. There was not a single, large-scale construction event, but several small-scale events that were accompanied by consumption activities. This pattern strongly suggests a permanent reinforcement of ties and commitments through feasting, which was required in order to finish the construction process. This scenario supports the idea of emerging leadership capable of mobilizing labor for the construction requirements. Nevertheless, the reliance on feasting as ritual practices, and the small scale of these events, suggests a limited power capacity and a weakly formalized authority, which needed to be constantly reinforced through the inferred ritual practices. 相似文献