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Using data describing the historical distribution of county seats in the United States, we (1) replicate the traditional ratio-variable test of the size-density law, (2) test a new multivariate, nonratio form of the law, and (3) introduce an alternative method of testing, one which avoids three possible problems in traditional analyses: ratio-variables, multicollinearity, and logarithmic transformation.  相似文献   
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In real-world applications, the k-shortest-paths between a pair of nodes on a network will often be slight variations of one another. This could be a problem for many path-based models, particularly those on capacitated networks where different routing alternatives are needed that are less likely to encounter the same capacity constraints. This paper develops a method to solve for k differentiated paths that are relatively short and yet relatively different from one another, but not necessarily disjoint. Our method utilizes the sum of a path's distance plus some fraction of its shared distance with each other path. A minimax algorithm is used to select the path whose largest sum of length, plus shared length vis-à-vis each previously selected path, is as small as possible. We present computational results for the Chinese railway system, comparing the paths generated by a standard k-shortest-path algorithm with those from our new model.  相似文献   
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A shipwreck from the early 3rd century BC was discovered in the Black Sea's suboxic depths off Ere?li, Turkey, during the 2011 E/V Nautilus expedition. Remote investigation revealed the trawl‐damaged remains of a merchant ship carrying multiple amphora types associated with Aegean and Pontic production areas. Also discovered were elements of the ship's hull that show evidence of both pegged mortise‐and‐tenon and laced construction. The wreck provides crucial archaeological evidence for both maritime connectivity and ship‐construction methods during a period of political and economic transition.  相似文献   
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孙丹 《东南文化》2018,(3):62-69
长江下游西部北阴阳营文化、薛家岗文化随葬猪下颌骨的习俗比较广泛,汉水流域甚至发展为主要以猪下颌骨随葬的葬仪。随葬猪下颌骨所彰显的财富与地位特征逐渐变强后再渐弱。距今7000年左右,即在随葬猪下颌骨的最初阶段,只体现出一定的财富属性。距今6000—4500年,随葬猪下颌骨隐含的财富与地位特征最强。之后,这种习俗渐趋消失,与财富、地位的关联性也微乎其微。随葬猪下颌骨的习俗可能是与黄河流域社会上层交流的要素之一。  相似文献   
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As the criterion used by archaeologists for determining early white porcelain is quite ambiguous, the origin of Chinese white porcelain remains a point of disagreement. In this study, we systematically investigate 61 typical Xing porcelains of the late Northern dynasties to the early Sui dynasty (550–600 CE) using spectrophotometer, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD), and analyze the differences between early white porcelain and celadon of Xing kiln in terms of their whiteness and raw materials characteristic. The results show that early white porcelain is a new type of ware that differs from celadon, which can be distinguished by whiteness, with a whiteness greater than 8% being early white porcelain and a whiteness less than 8% being celadon. It is assumed that the ancient potters created the whiter wares based on celadon by improving the glaze and selecting new raw materials for the body, but the production of this type of ware was short lived and subsequently refined in the Sui dynasty (581–618 CE) owing to the limited improvement in whiteness.  相似文献   
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徐团辉 《华夏考古》2015,(2):109-115,126
从战国初年的历史形势和韩国的发展战略出发,考虑韩国灭郑的军事策略,结合考古材料,韩国迁都宜阳、阳翟的记载应是可信的。对文献记载的混乱现象应予以全新解读:韩国迁都宜阳、阳翟的时候,平阳作为政治中心在继续使用。换言之,韩国在保持平阳都城地位的同时,迁都宜阳、阳翟,以此来服务灭郑的军事战争。宜阳和阳翟是具有浓厚军事色彩的临时性都城,带有战时陪都的性质。  相似文献   
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伪色诺芬《雅典政制》史料价值初探   总被引:1,自引:0,他引:1  
伪色诺芬《雅典政制》作为公元前5世纪后期雅典的历史文献,对于研究雅典政治状况、原提洛同盟"盟邦"与雅典的关系以及探析民主政治的实质具有重要的史料价值。作者主要从平民的权利、海上霸权两个方面论述雅典民主制保持完好的原因,评述"盟邦"主权遭到雅典侵夺的历史事实,从而证明雅典民主制乃是建立在全体雅典人对非雅典人剥削、奴役基础之上的。当政者所采取种种强化民主的措施,其目的都是为了维护雅典人的根本利益。  相似文献   
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