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101.
Chung-Chan Hung 《Journal of Earthquake Engineering》2013,17(6):759-776
A new version of the Full Operator Method (FOM) is proposed in this work. The numerical characteristics of the modified FOM (mFOM) are investigated, both theoretically and analytically. It is found that mFOM is unconditionally stable when the estimated stiffness of the structure is larger than or equal to the actual stiffness. Simulations using two numerical examples are carried out to demonstrate the capability of the mFOM. The seismic response simulation of a composite coupled wall system suggests that the mFOM is capable of generating reasonably accurate solutions despite the presence of structural complexity, material nonlinearity, and displacement control errors. 相似文献
102.
Mohammad Malakoutian Jeffrey W. Berman Peter Dusicka Arlindo Lopes 《Journal of Earthquake Engineering》2013,17(4):535-558
Previous research has proposed the Linked Column Frame (LCF) as a lateral load-resisting system capable of providing rapid return to occupancy for buildings impacted by moderate earthquake events and collapse prevention in very large events. The LCF consists of flexible moment frames (MF) and linked columns (LC), which are closely spaced dual columns interconnected with bolted links. The linked columns (LC) are designed to limit seismic forces and provide energy dissipation through yielding of the links, while preventing damage to the moment frame under certain earthquake hazard levels. The proposed design procedure ensures the links of the linked column yield at a significantly lower story drift than the beams of the moment frame, enabling design of this system for two distinct performance states: rapid repair, where only link damage occurs and quick link replacement is possible; and collapse prevention, where both the linked column and moment frame may be damaged.Here, the seismic performance factors for the LCF system, including the response modification factor, R, the system over-strength factor, Ω0, and the deflection amplification factor, Cd, are established following the procedures described in FEMA P695 [2009]. These parameters are necessary for inclusion of the system in the building code. This work describes the development of archetype structures, numerical models of the LCF systems, incremental dynamic analyses, and interpretation of the results. From the results, it is recommended that R, Ω0, and Cd values of 8, 3, and 5.5 be used for seismic design of the LCF system. A height limit of 35 m (115ft) is recommended at this time as taller LCFs are not considered in this study. 相似文献
103.
Kristin Ilves 《International Journal of Nautical Archaeology》2012,41(1):94-105
In the context of the development of different kinds of watercraft during prehistory an interdependent line of development for landing sites and harbours is often suggested, and used to argue that it is almost impossible archaeologically to locate small and early landing sites. Although the constructional properties of prehistoric watercraft suggest that landing‐structures were not absolutely necessary, there is nevertheless archaeological evidence of landing‐facilities from the Stone Age, as well as landing‐facilities for smaller boats to consider. This article will discuss to what extent ship archaeological evidence could be seen in a corresponding development to landing sites in its respective periods. © 2012 The Author 相似文献
104.
We have conducted a detailed taphonomic study of the avifauna of the Pitted Ware culture site of Ajvide on the Island of Gotland in the Baltic Sea, in order to investigate the fowling patterns and the taphonomic history of the bird remains. We have investigated cultural as well as natural modifications on the bird bones, fragmentation and fracture patterns, and performed a systematic surface modification study. No specific area for the deposition of bird remains or specific bird species was identified. All major anatomical parts of birds are present in the assemblage, but there is a dominance of specimens from the wing elements. Traces of cultural modification were observed on the bones, including cut marks, burning, modification (implements, beads, raw material), and gnawing marks. The bone surface modifications and fracture analysis indicate that the majority of the bird bones at Ajvide did not lie on the soil surface for an extended period of time before being deposited in the soil. Dry fractures increase while fresh fractures decrease towards the upper levels of the stratigraphy, indicating more extensive post‐depositional destruction. This may partly be connected to modern agriculture, but also to later use of the settlement area as a burial ground. The Ajvide assemblage contains a variety of birds living in different biotopes. However, bird hunting was mainly focused on sea birds. Auks and ducks are the most common families in the assemblage. We find it likely that the Ajvide hunters conducted organised hunting expeditions to two nearby islands for the hunting of auks, while it was possible to hunt other birds such as ducks closer to the site. The presence of medullary bone and bones from subadult birds indicates a main hunting season in late spring and early summer. However, comparisons with modern migration patterns indicate that hunting may have occurred throughout the year. Of special palaeozoological interest is the find of gannet (Morus bassanus), which apparently in Neolithic times visited the Baltic area more regularly than today. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
105.
Janet L. Smith 《Geografiska annaler. Series B, Human geography》2000,82(4):221-233
Sweeping changes in national policy aim to radically transform public housing in the United States. The goal is to reduce social isolation and increase opportunities for low income tenants by demolishing ‘worst case’ housing, most of which is modern, high‐rise buildings with high vacancy and crime rates, and replacing it with ‘mixed‐income’ developments and tenant based assistance to disperse current public housing families. Transformation relies on the national government devolving more decision‐making power to local government and public housing authorities. The assumption here is that decentralizing the responsibility for public housing will yield more effective results and be more efficient. This paper explores the problematic nature of decentralization as it has been conceptualized in policy discourse, focusing on the underlying assumptions about the benefits of increasing local control in the implementation of national policy. As this paper describes, this conceived space of local control does not take into account the spatial features that have historically shaped where and how low income families live in the US, including racism and classism and a general aversion by the market to produce affordable rental units and mixed‐income developments. As a result, this conceived space of local control places the burden on low income residents to make transformation a success. To make this case, Wittgenstein's (1958) post‐structural view of language is combined with Lefebvre's view of space to provide a framework in which to examine US housing policy discourse as a ‘space producing’ activity. The Chicago Housing Authority's Plan for Transformation is used to illustrate how local efforts to transform public housing reproduce a functional space for local control that is incapable of generating many of the proposed benefits of decentralization for public housing tenants. 相似文献
106.
营汛体系是清朝地方治理的基层军事系统,对地方治理具有十分重要的意义。一般而言,营汛体系形成之后相对稳定,但在湘西苗疆,受自然地理环境、历史民族人口、社会环境等的影响,该体系经历了多次进入、退出,它的建立、完善与调整过程表现出明显的不稳定性,反映出其“因势而变”的特征,这种特征凸显了湘西苗疆在国家一体化进程中的特殊性与差异性。 相似文献
107.
清代县级政区分等制度自雍正年间提出,至乾隆十二年后大体厘定。但乾隆十二年至四十三年间,仍然发生了高达124次的缺分等第调整,其中又以中、简缺升为最要、要缺为主,迫使清廷于乾隆四十三年出台了繁简互换的规定并得到较为严格的执行,但仍有一些例外。自此直至道光朝仍有相当数量的缺分调整,咸丰、同治两朝改缺甚少,到了光绪末、宣统之际再度升温。各省内缺分分布存在反“中心—边缘”,“中心—边缘”双中心,沿河、沿海、交通线的线状分布,贴近经济中心等诸多模式。以1911年为例,附郭县的缺分等第整体上在府内占据优势地位,但仍有48个府存在附郭县缺分等第低于府内其他厅州县的情况。州县缺分与优瘠缺的关系亦非一一对应,湖南的案例再次证明了这一点。 相似文献
108.
关于太平天国史研究的几个问题 总被引：1，自引：1，他引：1
太平天国史的研究,有几个问题需要重新认识。洪秀全早期的宗教宣传和活动并非“纯粹的宗教宣传”,而是具有政治意义和策略价值;农民领袖平均、公有思想作为一种鼓舞农民斗志的理想无可厚非,洪秀全等所实施的现行政策与公有制理想是有距离的,他们已注意到切合实际问题,所采取的实际政策是灵活的;由平均、公有思想转到仿行资本主义思想是一种进步,这种转变不是“脱离实际”的,而是有客观因素,具有现实性;拜上帝信仰与太平天国相始终,它使太平天国兴,又使太平天国亡;太平天国起义具有革命性质,是一场具有资产阶级民主革命的某些特点或色彩的农民革命,并起了重要的历史作用。 相似文献
109.
欧阳凤莲 《世界古典文明史杂志》2009,(2)
商鞅学派的户籍管理思想在《商君书》中多有体现,而秦是中国户籍制度开创与基本规模奠定的时期。本文通过对二者在户籍的编制与管理、取得户籍的资格、户籍的分类、户籍登记的内容以及户籍的变更等几个方面的比较,考察商鞅及其学派的户籍管理思想在秦国政策中的渗透。 相似文献
110.
一个国家的水陆交通与商业发展紧密联系在一起,交通越便利,商业越发达。中古时期英国的交通状况如何?目前在国内史学界还是一个冷僻的课题。要研究中古时期英国的商业经济,必然涉及到交通问题。根据近年来英国出版的相关文史资料,具体考察了12～14世纪期间英国的水陆通行及商业运输情况,提出了以下两点看法:一、由主干道即“王家大道”、地方道路和乡村小道所组成的陆路系统已经比较完整,可以保证商业运输的需要;大规模的陆路运输不仅可以有效组织,而且出现了比较高级的“公共运输人”。二、通航水路相当发达,尤其在东部地区水运河道密布,城市和大的集市都非常繁荣;水运价格也比陆运低得多。不可否认,以现代人的标准看,当时的水陆交通还障碍重重,运输效率不高。但是,这个时期英国的水陆交通条件已经为商业运输提供了必要保障。 相似文献