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This article aims at assessing the role of related variety, that is, the relatedness of knowledge bases used by different sectors within a region, as a major driver of clusters’ development. Some recent theoretical papers underline the role of clusters as ‘knowledge platforms’ organizing the recombination of technologies in overlapping industries, following the seminal definition of clusters by Porter as ‘geographic concentrations of linked industries’. In order to investigate the role of related variety in cluster dynamics, we analyse the patterns of development of clusters specializing in photonics in Europe. Photonics constitutes a new and rapidly evolving set of technologies with a high expected degree of technological recombination. However, due to inadequate traditional sectoral classifications, we propose an original method to delineate the perimeter of photonics in patent databases. A two-step algorithm is then used to identify systematically photonic clusters in Western Europe at the local level. In the last part of the paper, a typology of technological trajectories of clusters over the last decades is developed and then correlated with a set of quantitative measures of technological relatedness. The results highly confirm the role of related variety as a major driver of success, particularly for the biggest European clusters.  相似文献   
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There has been noticeable development in the protection of linear infrastructure by UNESCO, whether on its cultural, technological or historical merits. However, with the exception of other means of transport incorporated within the field of industrial archaeology or recognised by the CIIC under the category of cultural routes, little or no consideration has been given to roads built from the mid-eighteenth century to the early part of the twentieth century. In view of this situation, this paper has the following aims. Firstly, to define the concept of ‘modern road’ and provide a brief analysis of the historical development and current situation of the same. Secondly, to assess the main contributions made to date regarding the heritage dimension of modern roads. Thirdly, to reconstruct the process of defining linear cultural landscapes, historic transportation corridors, cultural routes and heritage canals, railways and roads, in accordance with the considerations raised by ICOMOS and UNESCO. Finally, to contribute to the debate on the definition, characterisation and assessment of modern roads as world heritage assets, both intrinsically and in relation to established heritage categories.  相似文献   
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ABSTRACT

The concept of topoiesis of textual space addresses an analysis of the spatial elements that tend to provide a meaning to the literary text. Based on textual semiotics where there is an organized relational system of meanings, in this article we propose that it is possible to determine the function of space as a meaning issue from three different literary text instances (event or motive; character; and object). This distinction will permit a deeper interpretation of the sense of space in the literary text.  相似文献   
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The high Andes of western South America feature extreme ecological conditions that impose important physiological constraints on humans including high-elevation hypoxia and cold stress. This leads to questions regarding how these environments were colonized by the first waves of humans that reached them during the late Pleistocene. Based on previous research, and aided by human behavioral ecology principles, we assess hunter-gatherer behavioral strategies in the Andean highlands during the late Pleistocene and early Holocene. Specifically, we formulate three mobility strategies and their archaeological expectations and test these using technological and subsistence evidence from the six earliest well-dated highland sites in northern Chile. Our results suggest that all of the studied sites were temporarily occupied for hunting, processing animals, and toolkit maintenance. The sites also exhibit shared technological features within a curatorial strategy albeit with different occupation intensities. From this evidence, we infer that the initial occupations of the highlands were logistical and probably facilitated by increased local resource availability during a period of environmental amelioration.  相似文献   
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Relying on stochastic frontier analysis we propose a methodology to study the technological characteristics and cost efficiency levels related to the provision of public infrastructure for basic utilities. The methodology assumes a cost minimizing behaviour on the part of public officials when planning the construction of local infrastructure, which is represented by way of a flexible translog cost function. Introducing relevant definitions of scale economies, associated with larger numbers of inhabitants and dwellings, as well as economies of density, brought about by reductions in urban dispersion, we analytically determine the optimal population densities for which average cost is minimized. We illustrate our model with the water cycle sector, including water distribution, sewage collection and cleansing of wastewater, and considering data at the municipality level for the Spanish region of Castilla y León. The obtained results indicate potential cost savings in the form of decreasing average costs, as relevant scale and density economies are present, along with large inefficiency levels. Relevant policy guidelines favouring larger and denser urban sizes are drawn, as the observed cost excess is the result of a general suboptimal urban size in terms of population density, and the negative effects of dispersed settlement patterns.  相似文献   
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Classical industrial districts' literature is not focused on the role played by external ties but gives more importance to the local districts' endogenous development. Global value chains connect clusters to other external agents through external linkages and constitute a framework to analyse the complex inter-linkages between clusters and other external agents. In the field of the external ties and the global value chain approach Academia is primarily focused on the ties which link clusters in developing nations to global markets, although global value chains also consider connections between clusters in similar activities and even when both are located in developed nations. Thus, external linkages are mainly performed by multinational enterprise (MNE) affiliates which play fundamental role of knowledge diffusers and absorbers in the process of knowledge exchange throughout global value chains. The work examines the process of knowledge exchange between clusters through external ties using the global value chain approach. For this purpose, empirical work is conducted with 22 face-to-face interviews to provide a case study about a leading cluster in the global ceramic tile industry. Results show that the basic knowledge to successfully compete is locally originated, although it can be complemented with global knowledge learnt or generated in other territories. MNE affiliates bridge structural holes through external ties and reduce knowledge asymmetries within global value chains. External ties on network-based governance chains exist, matter and affect clusters allowing upgrading even between developed nations.  相似文献   
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