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Higher dimensional algebra frees mathematics from the restriction to a purely linear notation, in order to improve the modelling of geometry and so obtain more understanding and more modes of computation. It gives new tools for noncommutative, higher dimensional, local to global problems, through the notion of «algebraic inverse to subdivision». We explain the way these ideas arose for the writters, in extending first the classical notion of abstract group to abstract groupoid, in which composition is only partially defined, as in composing journeys, and which brings a spatial component to the usual group theory: An example from knot theory is used to explain how such algebra can be used to describe some structure of a space. The extension to dimension 2 uses compositions of squares in two directions, and the richness of the resulting algebra is shown by some 2-dimensional calculations. The difficulty of the jump from dimension 1 to dimension 2 is also illustrated by the comparison of the commutative square with the commutative cube-discussion of the latter requires new ideas. The importance of category theory is explained, and a range of current and potential applications of higher dimensional algebra indicated.  相似文献   
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Understanding cooperation among authoritarian regimes remains a puzzle for researchers; in particular, those working in post-Soviet Eurasia. Research suggests that autocrats are becoming increasingly coordinated in their efforts to thwart democracy, with authoritarian-led regional organizations offering an effective vehicle to extend autocrat time horizons. In contrast, older studies, including insights from failed regional integration among former Soviet states, suggest that the absence of democracy limits cooperation, although in both cases there is a lack of detail on the mechanisms enabling or constraining relations between autocrats. This article addresses this shortcoming by developing a theoretical framework based around autocrat survivability or “regime security” and applying it to the important case of the newly formed Eurasian Economic Union (EAEU), drawing on original interview data with experts and stake-holders in Belarus, Kazakhstan, and Russia. The argument forwarded in this article is that concerns over regime security create antagonistic cooperation drivers. In the case of the EAEU, regime security provides a strong explanation for the inability of member states to coordinate policy. The implication is that future studies should pay close attention to the way the material and ideational aspects of authoritarian rule combine to drive, but also limit relations between autocrats.  相似文献   
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Recognizing that the vogue of postmodernism has passed, Simon Susen seeks to assess whatever enduring impact it may have had on the social sciences, including historiography. Indeed, the postmodern turn, as he sees it, seems to have had particular implications for our understanding of the human relationship with history. After five exegetical chapters, in which he seems mostly sympathetic to postmodernism, Susen turns to often biting criticism in a subsequent chapter. He charges, most basically, that postmodernists miss the self‐critical side of modernity and tend to overreact against aspects of modernism. That overreaction is evident especially in the postmodern preoccupation with textuality and discourse, which transforms sociology into cultural studies and historiography into a form of literature. But as Susen sees it, a comparable overreaction has been at work in the postmodern emphasis on new, “little” politics, concerned with identity and difference, at the expense of more traditional large‐scale politics and attendant forms of radicalism. His assessment reflects the “emancipatory” political agenda he assigns to the social sciences. Partly because that agenda inevitably affects what he finds to embrace and what to criticize, aspects of his discussion prove one‐sided. And he does not follow through on his suggestions that postmodernist insights entail a sort of inflation of history or historicity. Partly as a result, his treatment of “reason,” universal rights, and reality (including historiographical realism) betrays an inadequate grasp of the postmodern challenge—and opportunity. In the last analysis, Susen's understanding of the historical sources of postmodernism is simply too limited, but he usefully makes it clear that we have not put the postmodernist challenge behind us.  相似文献   
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This article is an exploration of concept of monks as “soldiers of Christ” in Byzantine Anatolia during the late sixth and early seventh centuries CE. Through a case study of Theodore of Sykeon, this article will explore monks as agents of continuity in the Byzantine Anatolia of the late sixth and early seventh centuries through Theodore's conflicts with the emperors, imperial authorities, and the regional episcopal hierarchy. The conflicts Theodore had with various authority figures of his time were about helping them see the right path of supporting Catholic orthodoxy as the normative belief system of Byzantine society and integrating his rural community of Sykeon into the wider web of imperial and episcopal urban patronage. Thus, conflict in this context was a catalyst for social order and stability rather than a symptom of social collapse. This article also fits into the historiography of the holy man as local patron in Late Antiquity, suggesting an alternate interpretation of this phenomenon as first put forward in Peter Brown's seminal works on this subject.  相似文献   
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This paper presents the findings arising from neutron activation analysis (NAA) of northern Chilean domestic ceramic samples from Caleta Vitor (n = 38) and clay samples (n = 15) from nearby valley, coast and highland contexts. This study presents the first NAA data set of ceramics spanning a temporal period of 1500 years (c.2000 to c.476 bp ) from the Vitor Valley as well as the first attempt to use NAA to characterize potential clay sources in the region. On the basis of this study, we argue that the majority of domestic ceramics from Caleta Vitor share compositional similarities with clay samples collected from nearby valleys, allowing us to infer that the Caleta Vitor populations primarily procured their clay for domestic ceramics from local sources throughout a 1500‐year period. Thus, despite the fact that there were inter‐regional interactions during this period that included the influence of powerful Andean polities, it would appear that domestic ceramics continued to be produced locally, and by implication it can be argued that such interactions did not substantially affect this sphere of material culture production. Further, the apparent continuities in domestic ceramic production allow us to reflect on local decision‐making processes throughout the cultural phases considered in this research.  相似文献   
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Efforts to address HIV/AIDS have brought new opportunities and resources to LGBT (lesbian, gay, bisexual, transgender) activism in many parts of the developing world. However, increased attention in terms of both political opportunities and economic resources is uneven across the diverse population of LGBT peoples and activists. Lesbian activists have reaped far fewer benefits than their gay men counterparts. Building on existing approaches to movement visibility and invisibility, we posit a ‘political economy of in/visibility’ to analyse lesbian activism in China and Myanmar, where activists face particularly restrictive political and economic conditions. Rather than focus on visibility as a movement pre‐condition, objective or strategy, we examine the sources of in/visibility and their interactions with activists’ agency; in/visibility emerges from political and economic conditions, but is continuously reshaped by activists who negotiate them. We demonstrate that, despite challenges, lesbian activists respond in ways that help advance LGBT rights advocacy broadly, sometimes even with tactics that their more visible gay counterparts avoid. These interactions subsequently influence the conditions that shape in/visibility. Investigating the political economy of in/visibility, therefore, has significant implications for understanding not only lesbian activism, but also LGBT advocacy and collective mobilization, especially under politically and economically restrictive conditions.  相似文献   
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Capacity design aims to ensure controlled ductile response of structures when subjected to earthquakes. This article investigates the performance of existing capacity design equations for reinforced concrete coupled walls and then proposes a new simplified capacity design method based on state-of-the-art knowledge. The new method is verified through a case study in which a set of 15 coupled walls are subject to nonlinear time-history analyses. The article includes examination of the maximum shear force in individual walls in relation to the total maximum shear force in the coupled wall system, and subsequently provides recommendations for design.  相似文献   
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