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1.
One of the most important phases of case‐oriented research is identifying the relevant population of cases. The best practice scheme suggests first identifying the positive and then the negative cases, based on the assumption that the population is small and known. This scheme is inapplicable when the population is unknown, as is the case with many public administration and public policy outcomes, which are often less visible. However, most research either ignores this difficulty or recommends a single case study. This article suggests that when the population is unknown scholars can apply the possibility principle to identify the relevant population of cases. In order to do so, a large dataset is required. In policy studies, the Comparative Agendas Project (CAP) can serve this aim. This article highlights CAP's applicability for case selection based on the possibility principle in two less visible policy outcomes: conversion and drift. In that, it not only addresses an overlooked challenge but also promotes both CAP as a useful tool for qualitative researchers and the expansion of comparative work on conversion and drift.  相似文献   
2.
Over a period of some 100 years it has gradually been accepted that the human skeletal remains found in the late nineteenth century in ancient gravels at Galley Hill, Kent are not those of early man, but are of much more recent date. This conclusion was finally verified by means of relative (N, F) and absolute (14C) dating. Here we present the results of further analysis of the remains from Galley Hill for their uranium content by a method having general application to the relative dating of fossil human and other mammalian bone.  相似文献   
3.
The transition from hunter-gathering to agriculture (Neolithic) spread gradually across Europe from the Southeast. A reduction in cultural diversity of crop farming practices has been previously observed by comparing pre-LBK Neolithic sites in Greece and the Balkans (dated about 8500 yr BP) to LBK Neolithic sites in Central Europe (dated about 7000 yr BP). The decrease in crop diversity is statistically significant even when considering only the species less likely to have been subject to smaller productivity due to climatic factors (reductions in growing season, temperature, daylight, etc.). This reduction in cultural diversity has not been explained previously. In this paper we show that spatial drift, which occurred on the front of the advancing wave of pioneer settlements, can explain the observed loss of diversity during the LBK range expansion. Our results suggest that spatial dimensions can have a relevant effect also in other case studies in which cultural drift is important.  相似文献   
4.
Structures designed according to earlier codes with inadequate seismic provisions have not performed satisfactorily during recent earthquakes. The seismic performance of an existing three-storey reinforced concrete building designed according to the 1963 ACI 313-63 is evaluated and compared to the performance of a similar frame designed according to current code provisions. Non-linear static and dynamic analyses of the reinforced concrete frames are conducted. In this study, a probabilistic approach is adopted where a large number of artificially generated ground motion records is used as input motion to the structure. The results of the analysis indicated the probability of various degrees of damage to be expected when the existing frame is subjected to different ground motion levels. This information is useful in the design of the required rehabilitation scheme to provide an identified level of protection.  相似文献   
5.
Jeff Ferrell 《对极》2012,44(5):1687-1704
Abstract: The consumerist economies of the late modern city, in combination with contemporary models of urban policing, operate to close down the public spaces of social life. In response, social groups dedicated to democratic urbanism utilize anarchic tactics of “dis‐organization” and direct action to reopen public space and to revitalize it with unregulated activity. Complicating and animating these spatial conflicts is the issue of drift. On the one hand, consumerist economies and contemporary policing strategies exacerbate urban drift, spawning the very sorts of spatial transgression they seek to control. On the other hand, many of the progressive movements that battle for open space and alternative economic arrangements themselves embrace a culture of drift, and explore drift for its anarchic and progressive potential. In this context drift can usefully be investigated as an emergent form of epistemology, community, and spatial politics.  相似文献   
6.
If RC structural walls are properly designed and proportioned, these walls can behave in a ductile manner. To achieve this goal, the designer should provide adequate strength and deformation capacity of structural walls corresponding to each performance level (e.g. immediate occupancy, life safety and collapse prevention). This study investigates the drift and ductility capacities of T-shaped structural walls on the basis of results from experimental tests and sectional analyses. To determine proper deformation capacities for T-shaped structural walls, structural performances of T-shaped walls were evaluated with several parameters such as longitudinal reinforcement ratio, distribution of longi-tudinal reinforcement, lateral confinement ratio, and axial load ratio. Based on these results, the level of deformation capacity specified in current design provisions (ICBO, UBC 1997), which were expressed as both strain-based damage limit and interstorey drift ratio, were evaluated.  相似文献   
7.
We document and quantify a significant reduction in crop diversity in the early central European Neolithic using a large multi-site database of archaeobotantical remains we compiled from published Neolithic sites across southwest Asia and Europe. Two hypotheses are proposed to account for the observed changes: one which claims that the different environmental conditions of central Europe selected for a different set of crop choices and strategies than in use in southeast and Mediterranean Europe; and a null hypothesis that explains the change as a drift process associated with a small founding population that subsequently undergoes rapid expansion. Through an agent-based simulation model, we test the null hypothesis and demonstrate that the drop in diversity exceeds that predicted by a drift process. We conclude by re-evaluating the possible adaptive changes underlying crop use in early Neolithic Europe.  相似文献   
8.
The present study was an attempt to document changes in frequencies of dental morphology traits and understand phenetic affinities of Parsis, who migrated to the Indian subcontinent around the 8th century. Despite successfully integrating themselves into the Indian society, they have retained their ethnicity and distinct cultural practices. This study was conceived as a result of an excavation at the site of Sanjan, Gujarat which, as per historical records, is believed to be the first town in the Indian subcontinent with a large Parsi settlement thereby facilitating a diachronic comparison between the ancestral and extant Parsi groups. We compared and analysed dental traits between the two groups expecting a very close relationship between them owing to their ancestor–descendent relationship. Eleven discrete dental traits were selected and scored using the Arizona State University Dental Anthropology System (ASUDAS). Frequency changes were assessed by comparing trait frequencies; whereas phenetic affinity between Parsis was assessed by statistically comparing them with 13 populations using Smith's mean measure of divergence (MMD) statistic. Comparison of dental trait frequencies between Sanjan and extant Parsi samples show significant differences in incisor morphology, Carabelli cusp and Hypocone development. Trait frequencies, MMD values and 2D multidimensional scaling (MDS) plot indicate that extant Parsis and Sanjan samples are distantly separated from each other. Extant Parsis show closer affinity to low caste Mahars and tribal Madia Gonds than South and Central Asian groups. Sanjan is distant from all other groups including extant Parsis. It is likely that genetic drift accentuated by their small numbers and strict endogamy has resulted in divergence of Parsi groups. Similarly, their convergence with Maharashtran groups indicates admixture of Parsis with local groups, which supports earlier conducted mtDNA studies. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
9.
Film as a tool for learning offers considerable opportunity for enhancing student understanding. This paper reflects on the experiences of a project that required students to make a short film demonstrating their practical understanding of qualitative methods. In the psychogeographical tradition, students were asked to “drift” across the urban environment and record their own experiences of the places encountered. The findings suggest this “drift-film” strategy can be successful in sensitizing individuals to the benefits of qualitative methods, can enhance students' ability to story-board and structure their arguments, and develop key editing skills which can be transferred to future employability.  相似文献   
10.
The role of residual deformations when evaluating the performance of multi-storey frame structures subjected to ground motion is investigated in this paper. The limitations of damage indices available in the literature, either based on ductility, energy dissipation or a combination of both, in capturing such a significant aspect of the seismic response of frame structures are discussed. The concept of residual deformations as a critical complementary indicator to cumulative damage, introduced in a companion paper (Part I) for single-degree-of-freedom (SDOF) systems, is herein extended to multi-degree-of-freedom (MDOF) frame systems. The seismic performance of multi-storey frame structures, either representative of new designed or existing structures, is investigated, focusing on the response in terms of residual deformations. Residual deformations are shown to be sensitive to the hysteretic rule adopted, to the system inelastic mechanism as well as to the seismic intensity. The influence of higher modes and P-Δ effects on the final residual deformations is addressed. A combination of maximum drift and residual drift in the format of a performance matrix is used to define the system's global performance levels and is then extended to a framework for an alternative performance-based seismic design and assessment approach.  相似文献   
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