大数据背景下基于社交网络的聚类随机游走抽样算法研究

数字经济时代,社交网络作为数字化平台经济的重要载体,受到了国内外学者的广泛关注。大数据背景下,社交网络的商业应用价值巨大,但由于其网络规模空前庞大,传统的网络分析方法 因计算成本过高而不再适用。而通过网络抽样算法获取样本网络,再推断整体网络,可节约计算资源, 因此抽样算法的好坏将直接影响社交网络分析结论的准确性。现有社交网络抽样算法存在忽略网络内部拓扑结构、容易陷入局部网络、抽样效率过低等缺陷。为了弥补现有社交网络抽样算法的缺陷,本文结合大数据社交网络的社区特征,提出了一种聚类随机游走抽样算法。该方法首先使用社区聚类算法将原始网络节点进行社区划分,得到多个社区网络,然后分别对每个社区进行随机游走抽样获取样本网 络。数值模拟和案例应用的结果均表明,聚类随机游走抽样算法克服了传统网络抽样算法的缺点,能够在降低网络规模的同时较好地保留原始网络的结构特征。此外,该抽样算法还可以并行运算,有效提升抽样效率,对于大数据背景下大规模社交网络的抽样实践具有重大现实意义。     

冷战后的中美政治安全关系

冷战结束十年以来 ,美国的对华政策依然摇摆不定。之所以如此 ,是因为十年来美国视中国为敌还是为友 ,或者非敌非友 ,至今还未定性。而美国难于在其国际政治安全战略中给中国定性的原因 ,则与以下的三个层次密切相关 ,即美国的国内政治层次、中美关系的发展层次和全球层次。     

The Myth of the Computer Hacker

The seriousness of computer hacking is not exaggerated, it is far worse than that. The computer hacker has attained the status of myth; society associates all computer crime with a mythical perpetrator that bears no resemblance to reality. This paper will argue that in the early stages of the myth the computer hacker was regarded as a highly skilled but mentally disturbed youth who has an unhealthy association with computers. The new reality of electronic commerce resulted in pressures that culminated in the computer hacker becoming regarded as a dangerous criminal. A thorough analysis of the statistics will demonstrate that the majority of computer intruders are neither dangerous nor highly skilled, and thus nothing like the mythical hacker.     

完善我国证券监管的几点法律思考

加强证券监管和完善证券监管的法制建设现已成为各国共识。我国的证券市场经过二十年的发展, 在证券监管法制建设方面虽已取得可喜的成绩, 但仍面临着许多问题和挑战。本文现就我国证券监管的法制建设有关问题做些思考。     

伊朗核危机与中国石油安全

伊朗核危机中,伊朗凭借其地缘、能源“优势”大力开展“政治性能源外交”,与美国展开“能源博弈”,这一状况将对中国的石油安全造成一定的影响。为了突破能源“困境”,中国需要做出一些“战略性”的政策调整。     

特许经营:未来的选择——兼议电子商务与特许经营之互补关系

特许经营在世界各地强劲的发展着 ,它既是市场高度化的结果 ,又是促使市场进一步发展的重要条件。它的主要优势在于 :1 对中小投资者来说具有低风险和低门槛进入的便利。 2 对主导企业来说是实现低成本扩张、规模效益以及加大无形资本边际回报的途径。 3 对这种经营方式本身来说它能随着IT行业的迅猛发展 ,可以与电子商务形成优势互补 ,所以特许经营将成为经营方式未来的选择     

Community involvement in land regularization for informal settlements in Tanzania: A strategy for enhancing security of tenure in residential neighborhoods

This paper documents and analyzes how landholders managed to uplift status of their neighborhood from hazard land as designated by the 1978 master plan to a regularized residential settlement through land regularization in Dar es Salaam city. Specifically, explores policy framework governing land regularization and how the local community explored the opportunities it offers. Documents the local community planning and land regularization processes undertaken focusing on land use planning, drainage construction, and cadastral survey and discuses how financial resources were raised, trust was built as well as factors which sustained community involvement towards meeting their interests of securing tenure. The paper also, draws challenges facing land regularization policy and recommends areas for further interventions commensurate with the human dimension challenges in securing tenure.Underlying community involvement, those aspects of community, which have been connected to the idea of social capital namely existence of committed leadership in land development matters, embracing mechanism for participatory decision making process and educational background to local leaders were particularly important in determining success for the case. Others include economic ability to contribute, high proportion of landholder settlers, land conflict task force formulation, local consensus to solve commonly felt problems, existence of strong community organization, and unwritten norms put in place to regulate individual behavior in building construction. Weak legal recognition of informal settlement, lengthy and bureaucratic procedures in planning and approval of regularization plans, weak knowledge on land management matters, short-term title deeds with low financial betterments, political popularity are identified critical challenges.Some of recommendations put forward include formalization of the grass-roots role in decision-making, decentralizing some of land development control functions to sub-ward leaders and training the same in basic land management matters. Others include definition of norms; by-laws and government facilitation of informal land parceling. Besides community support should be sought so as to create partnership in the promotion of security of tenure in informal areas. The study concludes that, unless land development activities ongoing in informal settlements are closely monitored and regulated as the settlement grow, it will be too costly socially and economically to retrofit once the settlement have identified.     

基尼系数合意值和警戒线的探讨

 近年来，很多学者对基尼系数的经验法则尤其是警戒线提出了质疑。本文首先分析了收入分配的合意类型，然后依据相对贫困、贫富差距及中等收入者的收入份额三个指标来界定合意的收入分配，最后根据合意收入分配确定基尼系数的合意值和警戒线。本文结论表明，0.3—0.4可以被认为是基尼系数的合意值,0.4作为基尼系数警戒线也是比较合理的。     

电子政府的信息网络安全及防范对策

本文从信息网络系统、安全管理、安全技术人才等方面分析了我国电子政府信息网络的安全问题 ,结合我国电子政府的现状与特点 ,提出了电子政府信息网络安全的防范对策 ,即构建一个由网络技术支撑层、网络技术应用层、网络管理层、网络安全人才层组成的信息网络安全体系结构。     

網絡組織成員合作的穩定性模型分析

本文應用博弈論建立了一個網絡組織成員合作的穩定性模型,通過模型分析作者提出網絡組織的穩定性依賴於多種因素,其中,信任機制、懲罰機制是網絡組織穩定的基本因素。本文通過對中國網絡組織的一般性分析,指出特殊主義文化背景下的中國網絡組織的信任機制和懲罰機制更多的來源於非正式制度,而非正式制度作用的空間局限性,是導致中國區際網絡組織穩定性差的重要原因,本文最後提出了中國網絡組織穩定性提升的建議。