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71.
A simplified model useful for assessing economic losses due to moderate seismicity events in urban areas has been developed by studying the behavior of buildings before yielding their structural system, allowing for nonuniform stiffness along their height. In particular, buildings are modeled as cantilever shear beams with uniform mass and parabolic reduction of lateral stiffness. This particular stiffness distribution is relevant, as it could be expected to occur in buildings where earthquake action is a critical structural design criterion. The equation of motion governing the dynamic behavior of the proposed model is solved analytically, finding mode shapes in terms of first and second zero-order Legendre functions. The solution is verified by comparing it with results obtained from fine mesh finite element models. The effect of reducing the lateral stiffness is then studied in the first five modes of vibration. Results include modal periods, mode shapes, modal participation factors, and derivatives of mode shapes. In general, it is found that effects of reduction of lateral stiffness in mode shapes are moderate when the lateral stiffness in the free end is smaller than about seventy percent of the lateral stiffness at the fixed end, but become significant for larger reductions. Effects are particularly important for the derivative of the mode shapes, which could play a significant role in estimating interstory drift demands in buildings. Model usefulness is showcased by analyzing a test case where both acceleration and drift demands are assessed by considering uniform beams and beams with parabolic stiffness variation, finding notable improvements by considering the latter. 相似文献
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Joan Negre Facundo Muñoz Juan Antonio Barceló 《Journal of Archaeological Method and Theory》2018,25(3):777-794
Most quantitative approaches to distributional analysis in archaeology assume a homogeneous study surface that is amenable to easy generalisations. This framework has been widely used to describe settlement processes, disregarding the spatial heterogeneity inherent to geographic reality. In other words, researchers have often assumed that the correlation between the elements of a spatial distribution is a function of the Euclidean distance (i.e. straight line distance) between them. Other archaeological studies have tested alternative measures to Euclidean distances, such as cost-based ones, both to describe optimal routes and to assess spatial autocorrelation in a point pattern. Nevertheless, until now there has been no suitable model to introduce these measures into spatial statistical equations. In order to overcome this obstacle, we approach the implementation problem inversely by embedding the spatial pattern under study into a Euclidean frame of reference based on its cost-distance pairwise matrix. This paper describes the application of this methodology on one of the main tools used by archaeologists to assess settlement patterns: Ripley’s K function. We present two case studies, covering both macroscale and mesoscale, with significant variations in the results depending on the use of the Euclidean or cost-based approach. Data, functions and results have been R-packaged for the sake of reproducibility and reusability, allowing other researchers to build upon our methods. 相似文献
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Jonas M. Nordin 《International Journal of Historical Archaeology》2018,22(4):663-685
This paper deals with the presence of Sámi in central and southern Sweden in the seventeenth century. The Nordic countries have generally been believed to be ethnically homogeneous, with the** colonial subjects not being present in the center of these empires. If the multicultural aspects of early modern Nordic countries are at all discussed, Sámi and other ethnic groups are understood as peoples living on the outskirts of the empires. This notion has cemented an idea that cities such as Copenhagen or Stockholm were inhabited solely by peoples from southern Scandinavia and the continent. Drawing on the experience of the role and presence of indigenous people from the Americas and the Arctic in cities such as London in the seventeenth century, this paper examines the multi-ethnic aspects of early modern Stockholm, capital of Sweden, as an imperial center. 相似文献
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Eric D. Tourigny 《International Journal of Historical Archaeology》2018,22(4):843-864
Much of the meat consumed in nineteenth-century southern Ontario (Upper Canada) came in the form of preserved barreled products. The specific ways of obtaining, preparing and consuming these products resulted in unique regional foodways. Through analyses of historical and archaeological evidence, this paper investigates how barreled meat was packed, shipped and purchased in Upper Canada and discusses the various ways its consumption impacted the lives of its residents and contributed to the formation of local identities. An investigation of butchery marks and body portion distributions lead to a possible method for archaeologically distinguishing between barreled and non-barreled meat assemblages. 相似文献
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Arturo Rodríguez Morató 《International Journal of Cultural Policy》2018,24(5):628-646
ABSTRACTThis article examines cultural policy strategies supporting urban regeneration, focusing on its particular characteristics in the Ibero-American context. We start by developing a systematic contrast between the different circumstances that have led to the emergence of these strategies in the Ibero-American sphere and in other parts of the world. Our examination of the Ibero-American regenerative experience also includes a consideration of the paradigmatic cases that arose initially in the Iberian Peninsula and the typological analysis of subsequent Latin American experiences. The consideration of all these different elements ends up providing a global vision of the specificity of the phenomenon in its Ibero-American context. 相似文献
80.
Biological invasions are one of the great threats to Earth’s ecosystems and biodiversity in the Anthropocene. However, species introductions and invasions extend deep into the human past, with the translocation of both wild and domestic species around the world. Here, we review the human translocation of wild plants and animals to the world’s islands. We focus on establishing criteria used to differentiate natural from human-assisted dispersals and the differences between non-native and invasive species. Our study demonstrates that, along with a suite of domesticates, ancient people transported numerous wild plants and animals to islands and helped shape ecosystems in ways that have important ramifications for modern conservation, restoration, and management. 相似文献