P2P技术与网络传播的未来

伴随着P2P技术和商业应用的发展,P2P技术对于未来网络传播可能产生的影响也成为一个令 人关注的问题。从目前来看,P2P技术对于网络传播的影响主要包括以下几方面:网络信息共享与 利用的方式与程度将进一步改变;围绕P2P技术思想展开的软件与信息产品开发,将在一定程度上 决定作为媒体的网络的未来面貌;P2P带来的去中心化特点将使互联网管理的难度进一步增加; P2P可能成为媒体间的交流与合作的新平台,也可能加速媒体形态的演化。从总体看,P2P技术未 来的社会影响程度,取决于政治、经济等各种力量的博弈结果,而这也将最终影响着互联网的未来。     

Will the ASA's Efforts to Improve Statistical Practice be Successful? Some Evidence to the Contrary

ABSTRACT

Recent efforts by the American Statistical Association to improve statistical practice, especially in countering the misuse and abuse of null hypothesis significance testing (NHST) and p-values, are to be welcomed. But will they be successful? The present study offers compelling evidence that this will be an extraordinarily difficult task. Dramatic citation-count data on 25 articles and books severely critical of NHST's negative impact on good science, underlining that this issue was/is well known, did nothing to stem its usage over the period 1960–2007. On the contrary, employment of NHST increased during this time. To be successful in this endeavor, as well as restoring the relevance of the statistics profession to the scientific community in the 21st century, the ASA must be prepared to dispense detailed advice. This includes specifying those situations, if they can be identified, in which the p-value plays a clearly valuable role in data analysis and interpretation. The ASA might also consider a statement that recommends abandoning the use of p-values.     

Stress-strength reliability of exponentiated Fréchet distributions based on Type-II censored data

In this paper, we consider inference of the stress-strength parameter, R, based on two independent Type-II censored samples from exponentiated Fréchet populations with different index parameters. The maximum likelihood and uniformly minimum variance unbiased estimators, exact and asymptotic confidence intervals and hypotheses testing for R are obtained. We conduct a Monte Carlo simulation study to evaluate the performance of these estimators and confidence intervals. Finally, two real data sets are analysed for illustrative purposes.     

Lower bound of average centered L2-discrepancy for U-type designs

Uniform designs are widely used in various scientific investigations and industrial applications. By considering all possible level permutation of the factors, a connection between average centered L₂-discrepancy and generalized wordlength pattern for asymmetrical fractional factorial designs is derived. Moreover, we present new lower bounds to the average centered L₂-discrepancy for symmetrical and asymmetrical U-type designs. For illustration of the theoretical results, the lower bounds for symmetrical and asymmetrical U-type designs are tabulated, and numerical results indicate that our lower bounds behave well and can be recommended for use in practice.     

On Hotelling’s T2 test in a special paired sample case

In a special paired sample case, Hotelling’s T² test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given.     

A new aging concept derived from the increasing convex ordering

In this paper, a comparison between the life distribution of a new unit with that of a used unit in the increasing convex order is made leading to a new class of life distributions which we call “new better than used in convex ordering of second order”. This class includes as subclasses the NBU and the NBUC and is a subclass of the NBUCA class. Preservation properties under convolution, random maxima, mixing and formation of coherent structures are established. Stochastic comparisons of the excess lifetime when the inter-arrival times belong to the NBUC(2) class are developed. Some applications of Poisson shock models and a test of exponentiality against NBUC(2) alternative are presented.     

A Factor-Adjusted Multiple Testing Procedure With Application to Mutual Fund Selection

In this article, we propose a factor-adjusted multiple testing (FAT) procedure based on factor-adjusted p-values in a linear factor model involving some observable and unobservable factors, for the purpose of selecting skilled funds in empirical finance. The factor-adjusted p-values were obtained after extracting the latent common factors by the principal component method. Under some mild conditions, the false discovery proportion can be consistently estimated even if the idiosyncratic errors are allowed to be weakly correlated across units. Furthermore, by appropriately setting a sequence of threshold values approaching zero, the proposed FAT procedure enjoys model selection consistency. Extensive simulation studies and a real data analysis for selecting skilled funds in the U.S. financial market are presented to illustrate the practical utility of the proposed method. Supplementary materials for this article are available online.     

Conjugal intimacy,gender and modernity in contemporary China

The new generation of modernity theorists have forecast the democratization of gender relations within intimate relationships in late‐modern times. Chinese society has undergone rapid and dramatic changes in its unique trajectory of political, social and economic reform. Using China as an example of a region which has been largely ignored in contemporary social theory, this article enters the debate to contest the extent to which conjugal relationships are democratized in line with modernity. We further test the assertion that modern marriages are characterized by increased self‐disclosure and communication between partners. Data from a national survey on Chinese families is analysed in relation to the level of self‐disclosure between husbands and wives; gender division of housework; household decision‐making; and home ownership. We highlight the impact of gender, cohort and location (urban, rural or migrant) on experiences of modernity and draw attention to the material, social and cultural factors which continue to shape conjugal relations in contemporary Chinese society. Based on our findings, we contest the argument that disclosing intimacy between intimate partners is a defining characteristic of modern relationships, and suggest that other social factors may condition degrees of self‐disclosure in marriage. Similarly, we question the extent to which heterosexual conjugal equality is attained: the cultural practices and values of patrilineal family organization, together with material circumstances, continue to influence marital relations in China.     

Associations between Students’ Perceptions of the Psychosocial School Environment and Indicators of Subjective Health in Finnish Comprehensive Schools

The study examined how far students’ perceptions of the psychosocial school environment are associated with self‐rated health, life satisfaction and subjective health complaints. Students’ perceptions were associated with one or more indicators of subjective health. Perceived health was better in direct proportion to positive perceptions. Student relations and school strain were the factors that stood out in both genders, with regard to all the health indicators. School engagement, parental support and educational aspiration were found to be important for overall perceived health of the students. This study indicates the importance of the psychosocial school environment for students’ health.     

Self as enterprise: digital disability practices of entrepreneurship and employment in the wave of ‘Internet + disability’ in China

ABSTRACT

Situated in China’s neoliberal context and its rapid development of information communication technologies (ICTs), this study aimed to examine how disabled people in China transformed themselves into new self-enterprising subjects in the wave of ‘Internet?+?Disability.’ In order to answer this question, this study tried to develop an analytical framework to illustrate the disability practices that situated in the ICTs and neoliberal context, underpinned by the discourse of ‘self as enterprise,’ and demonstrated by the practices of entrepreneurship and employment. Based on the research design of case studies and methods that included ethnographic participant observation and in-depth interviews, this study explained how a disabled entrepreneur, Mr. Yuan, took advantage of the wave of ‘Internet?+?Disability’ to realize his dream of entrepreneurship and face the uncertainties of a precarious entrepreneurship. It also explained how Mr. Yuan’s employees achieved their dreams of employment but suffered the precariousness of enterprising subjects.