A Minimax Method for Finding the k Best “Differentiated” Paths

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.     

Tracing the origin of Chinese early white porcelain in the late sixth century—evidence from Xing kiln

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.     

韩国迁都宜阳、阳翟考辨

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。     

伪色诺芬《雅典政制》史料价值初探

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。     

试论《武王践祚》的文本流变

《上海博物馆藏战国楚竹书》(七)所收《武王践祚》,实为两种战国"简本"(甲本和乙本)的合抄。传世本则是参考了这两种简本,合编整理而成。与甲本相比,乙本在叙事及文字上更接近于原始的记录,成文应早于甲本。但甲本与乙本之间并没有直接的文本传承关系,应是两系文本发展的不同形态。参照乙本,可以推测《武王践祚》的原初结构,并不包括武王勒铭段。从文献体裁及文章内容看,甲本及传世本的这一段文字,应是合编自其他文献。《武王践祚》三个本子的比较研究显示,早期文献在流传过程中,不仅存在着文字的增饰、丢失与改动等现象,同时还存在着同种文献不同形态的合编整理甚至是不同文献的合并现象。这对我们认识早期文献形成及流传的特殊性,并进而讨论早期文献的史料价值,无疑具有重要的参考意义。     

AN ECOLOGICAL SAFETY SHELTER ESTABLISHED ON THE SNOWY HIGHLAND

<正>On the snowy highland,the splendid view of mountains and waters vie with each other;the birds and beasts stroll idly as in a courtyard,and the flourishing woods and grasses stretch as far as the eyes can see.Is"Shambhala"a fairyland?Over the years,the central government and Tibet have focused on protecting the highland ecology and have attained impressive achievements.Under the blue sky     

DEM Algorithm for Progressive Collapse Simulation of Single-Layer Reticulated Domes under Multi-Support Excitation

In this paper, the Member Discrete Element Method (MDEM) is modified and perfected for three aspects: the algorithm itself, loading and computational efficiency, and to accurately and quantitatively simulate the progressive collapse for large-span spatial steel structures. In addition, the corresponding computational programs are compiled. First, from the perspective of the method, a meshing principle for discrete element models is determined, a treatment for material nonlinearity and strain rate effect is proposed, and a damping model is established. Next, the Displacement Method is introduced to determine the multi-support excitation for the MDEM, and then motion equations of particles under multi-support excitation are derived. On this basis, the specific process of gravitational field loading is presented. Furthermore, parallel implementation strategies for the MDEM based on OpenMP are constructed. Finally, the collapse simulation of a 1/3.5-scaled single-layer reticulated dome shaking table test model under multi-support excitation is carried out. The comparison demonstrates that the ultimate load and failure mode as well as the complete collapse time of the numerical results are consistent with the experimentally measured responses, and the configuration variations from member buckling and local depression until collapse failure are fully captured. Moreover, the displacement time-history curves obtained using MDEM are almost identical to the experimental measurements, and there is a nuance only in the amplitude. It is verified that MDEM is capable of precisely addressing the collapse failure for large-span spatial steel structures. Additionally, the failure mechanism for structures of this type is naturally revealed.     

神话对唐诗的影响

唐诗中存在着大量取材于古代神话的诗作,这反映了神话对唐诗的显著影响,但这一文学现象很少为学界所关注。本文侧重于从美学角度探析唐诗对七类古代神话的运用。唐诗人不是歌咏原生态的古代神话,而是运用它们的象征意义抒情言志。唐诗大量取材古代神话的现象主要与唐代崇尚道教的社会环境及诗人的不幸的人生遭遇等有关。     

辽代琥珀来源的探讨

本文主要以中、西文献记载为依据,结合考古出土以及以往的研究成果,论证辽代的琥珀原材料很可能来自遥远的欧洲波罗的海沿岸.波罗的海琥珀由基辅罗斯北部诺夫哥罗德城,沿伏尔加河南下,到达地中海.再东经黑海、里海,达河中地区.然后经皮毛之路、丝绸之路进入辽境.