基于csQCA的P2P网络借贷平台信用影响因素

针对P2P网络借贷平台成交量及数量减少的现象,运用网络爬虫技术等方法,获取了上市系、国资系、风投系、创业系4个类别共40个P2P网络借贷平台的实际数据;建立了基于品牌信用、交易信用、人气信用、服务信用4个维度的P2P网络借贷平台信用评估模型;运用csQCA方法对其平台信用影响因素进行构型分析。研究表明:交易信用中的信息透明度是影响P2P网络借贷平台信用的主要要素,其次是品牌信用中的合规程度;高品牌信用是上市系和创业系P2P网络借贷平台高信用值产生的必要条件;高交易信用是国资系P2P网络借贷平台高信用值产生的必要条件。政府和P2P网络借贷平台应重点关注品牌信用和交易信用的变化,为借款人和出借人营造良好的交易氛围。     

A Lower Bound for the Wrap-around L2-discrepancy on Combined Designs of Mixed Two- and Three-level Factorials

The objective of this article is to study the issue of employing the uniformity criterion measured by wrap-around L₂-discrepancy to assess the optimal foldover plans. For mixed two- and three-level fractional factorials as the original designs, general foldover plan and combined design under a foldover plan are defined, and the equivalence between any foldover plan and its complementary foldover plan is investigated. A lower bound of wrap-around L₂-discrepancy of combined designs under a general foldover plan is obtained, which can be used as a benchmark for searching optimal foldover plans. Moreover, it also provides a theoretical justification for optimal foldover plans in terms of uniformity criterion.     

Geometric Anisotropic Spatial Point Pattern Analysis and Cox Processes

We consider spatial point processes with a pair correlation function, which depends only on the lag vector between a pair of points. Our interest is in statistical models with a special kind of ‘structured’ anisotropy: the pair correlation function is geometric anisotropic if it is elliptical but not spherical. In particular, we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial point patterns.     

二维奇异非稳态问题有限元解的误差估计

二维奇异问题的有限元方法是实际中经常会遇到的一类问题,对其解决有重要意义.本文讨论二维奇异非稳态问题的有限元方法,证明了弱解的存在唯一性,并给出有限元解的加权L2-模估计.     

On gart's test for interaction of second order

Gart (1972) ottered a Statistic on testing the hypothesis of no second-order interaction in a 2×s×t contingency table. The statistic was tn be used as an asymptotic chi-square with (s-1) (t-1) degrees of freedom. We show that this statistic suiters from the drawback that unless certain side conditions hold, the statistic would reject the null hypothesis with probability approaching one asymptotically even in the null case. Hence the statistic is not strictly valid for the hypothesis for which it was intended.     

RIDICULING THE ‘WHITE BREAD ORIGINAL’

The 1994 US Supreme Court decision in Luther Campbell et al. v. Acuff-Rose Music, Inc., written by Justice David Souter, reversed a lower court decision and argued in favor of the rap group 2 Live Crew's playful critique of Roy Orbison's ‘Oh Pretty Woman’ by its function as parody. This essay seeks to contextualize that decision by showing the roots of 2 Live Crew's recording in the practice of ‘covering’ – the re-recording of an existent popular composition – and thus the possibilities for redefining authorship that arose with the advent of digital technology. The compositional techniques allowed by computer programs led to the proliferation of sampling in the hip-hop community, thereby liberating sounds from the original content and reconfiguring them in new songs. The technique allowed a critical, and in some cases adversarial, stance to be taken towards long-standing Western definitions of authorship and ownership. 2 Live Crew added to this rich stew of possibilities the familiar and time-tested genre of parody. Their piece took what one judge referred to as the ‘white bread original’ of the Roy Orbison record and twisted about the implicit point of view with regard to gender and sexuality. Discussion of the legal complications that followed upon the suing of the group by the holder of the copyright in the Orbison song, Acuff-Rose Music, Inc., includes the apparently sanctioned use of the song in the Disney-produced film Pretty Woman as well as the use of other Orbison material in director David Lynch's Blue Velvet. The essay concludes with suggestions as to how the language of Justice Souter's decision allows not only for future parodies but also a reinvigoration of speech, one which calls into question power relationships codified in US copyright statutes.     

援苏抗德与丘吉尔的现实主义外交

二战初期,随着希特勒向西线大举进攻,丘吉尔临危受命,出任英国首相.面对纳粹德国的威胁,他从现实的国家利益出发,积极推动英苏合作.苏德战争爆发后,丘吉尔立即发表声明支持苏联抵抗纳粹德国的侵略.援苏抗德是丘吉尔现实主义外交的代表性例证.     

基于加权组合和最小二乘法改进的GM(2,1)模型

文章通过分析指出了GM(2,1)模型存在灰微分方程与白化方程无法匹配以及默认经过初始值点的缺陷;利用权值p1、p2对一阶灰导数和背景值进行加权组合,建立了GM(2,1)模型的一种改进形式--GM(2,1,p1,p2模型,利用最小二乘法确定系统最终参数.实例验证结果表明,改进GM(2,1)模型具有更高的预测精度.     

Comparing several experimental groups with a control in the multivariate case

This paper presents a multivariate extension of Dunnett's test for comparing simultaneously k treatment group means with a single control group mean. A test based on Hotelling T²statistics is presented and approximate critical values are evaluated for the case of equal numbers of observations in each group, for the .05 and .01 levels of significance, for 1 to 5 variates, for 1 to 10 treatment groups, and for varying degrees of freedom. The accuracy of the procedure for generating approximate critical values is assessed via simulation studies conducted for selected cases and an example is presented using real data.