产业集群企业网络体系:系统建构与结构分析

理论与实践的深入发展迫切要求加强产业集群绩效评价及其比较的定量研究,而集群企业网络体系及其结构分析是集群绩评价的基础和难点。本文运用系统论和社会网络分析工具,对集群企业网络体系系统建构和结构分析做了一个初步的探索性研究,认为集群企业网络体系是集群系统的核心层次,其结构特征可以通过网络密度、网络连通性、群体中心性、小团体结构和规则同型性等变量进行刻画,并具体阐释了各变量的分析方法及其对于集群企业网络分析的意义。     

一类具有时滞的神经网络的稳定性分析

对具有广泛应用价值的时滞Ｈｏｐｆｉｅｌｄ神经网络系统,建立了系统平衡点存在唯一的充要条件,利用常数交易法并结合不等式分析技巧讨论了神经网络模型的全局指数稳定性,获得了系统的平衡点全局指数稳定的充分条件。     

构建商业银行信贷风险分类预警模型

针对我国各类银行全面实行贷款风险五级分类管理,文章提出了一种信贷风险分类预警的方法。该方法首先应用聚类方法对指标进行筛选,然后以熵权法构建贷款风险综合指数,最后采用模糊神经网络实现对信贷风险的分类预警。该方法在综合考虑财务与非财务因素对信贷风险产生影响的同时,还可以通过对风险指标的敏感性分析来把握主要风险来源,为风险的防范工作提供重要的依据。     

"计算机网络"课程的教学改革与实践

计算机网络及其应用技术正处在一个飞速发展时期,理论与实验教学均应适应这种变化,以全面提高学生的综合素质。介绍了计算机网络课程的教学内容、教学方法与教学手段的改革实践;紧密结合理论教学,探讨了计算机网络实验课程建设,提出了一套可行的实验方案及实验室管理的建议。     

An intuitive risk factors search algorithm: usage of the Bayesian network technique in personalized medicine

The article focuses on the application of the Bayesian networks (BN) technique to problems of personalized medicine. The simple (intuitive) algorithm of BN optimization with respect to the number of nodes using naive network topology is developed. This algorithm allows to increase the BN prediction quality and to identify the most important variables of the network. The parallel program implementing the algorithm has demonstrated good scalability with an increase in the computational cores number, and it can be applied to the large patients database containing thousands of variables. This program is applied for the prediction for the unfavorable outcome of coronary artery disease (CAD) for patients who survived the acute coronary syndrome (ACS). As a result, the quality of the predictions of the investigated networks was significantly improved and the most important risk factors were detected. The significance of the tumor necrosis factor-alpha gene polymorphism for the prediction of the unfavorable outcome of CAD for patients survived after ACS was revealed for the first time.     

城乡困难家庭的求助网络及其政策启示

文章使用“城乡困难家庭调查”2014年跟踪数据,对我国城乡困难家庭的求助网络结构和家庭因素进行分析,发现：血缘和亲缘关系仍是我国城乡困难家庭最天然的帮扶网络,但官方社会救助系统的作用已超过民间系统,邻里朋友仅在血亲和官方系统失灵时起补充作用;基层治理结构对求助网络的城乡差异产生影响,流动人口家庭求助网络呈现多元均衡的特征,但面临官方救助系统的制度性缺失;人口规模、低保资格两个家庭因素对城乡困难家庭求助网络有显著影响。文章认为,应进一步发挥社会力量的作用,针对我国城乡困难家庭建立官民并举、多元协作的社会救助政策体系。     

Good health and the bridging of structural holes

Bridges that span structural holes are often explained in terms of the entrepreneurial personalities or rational motivations of brokers, or structural processes that lead to the intersection of social foci. I argue that the existence and use of bridges in interpersonal networks also depends on individuals’ health. Poor health may make it more difficult to withstand the pressures and to execute some of the common tasks associated with bridging (e.g., brokerage). I examine this possibility using egocentric network data on over 2500 older adults drawn from the recent National Social Life, Health, and Aging Project (NSHAP). Multivariate regression analyses show that both cognitive and functional health are significantly positively associated with bridging, net of sociodemographic and life-course controls. The relationship between functional (kinesthetic) health and bridging appears to be partially mediated by network composition, as older adults who have poorer functional health also tend to have networks that are richer in strong ties. Several potential mediation mechanisms are discussed. Cognitive function remains significantly associated with bridging net of network composition, suggesting that the inherent challenges of maintaining bridging positions may be more difficult to cope with for those who have cognitive impairments than for those who have functional impairments such as limited mobility. An alternative explanation is that cognitively impaired individuals have more difficulty recognizing (and thus strategically using) bridges in their networks. Theoretical implications and possibilities for future research are discussed.     

Clustering in weighted networks

In recent years, researchers have investigated a growing number of weighted networks where ties are differentiated according to their strength or capacity. Yet, most network measures do not take weights into consideration, and thus do not fully capture the richness of the information contained in the data. In this paper, we focus on a measure originally defined for unweighted networks: the global clustering coefficient. We propose a generalization of this coefficient that retains the information encoded in the weights of ties. We then undertake a comparative assessment by applying the standard and generalized coefficients to a number of network datasets.     

Nonlinear models of disability and age applied to census data

It is usually considered that the proportion of handicapped people grows with age. Namely, the older the man/woman, the more the level of disability he/she suffers. However, empirical evidence shows that this assessment is not always true, or at least, it is not true in the Spanish population. The study tries to assess the impact of age on disability in Spain. Each gender has been treated separately because it can be shown that men and women have their own pattern of behaviour. Three different methods of estimation have been used to check the link between those variables. The results seem to support the idea that the relationship among age and the intensity of disability is not always direct. One of the concluding remarks in this analysis is that the method of estimation has a great incidence in the final results, especially in central ages between 20 and 80 years old.     

Popularity breeds contempt: The evolution of reputational dislike relations and friendships in high school

In this study, we examined the dynamics of the perception of “dislike” ties (reputational dislike) among adolescents within the contexts of friendship, perceived popularity, substance use, and Facebook use. Survey data were collected from a longitudinal sample of 238 adolescents from the 11th and 12th grades in one California high school. We estimated stochastic actor-based network dynamic models, using reports of reputational dislike, friendships, and perceived popularity, to identify factors associated with the maintenance and generation reputational dislike ties. The results showed that high-status adolescents and more frequent Facebook users tended to become perceived as or stay disliked by their peers over time. There was a tendency for friendships to promote the creation and maintenance of reputational disliking but not vice versa. Adolescents tended to perceive others as disliked when their friends also perceived them as disliked. There was no evidence that either cigarette smoking or drinking alcohol affected reputational dislike dynamics. This study highlights the important role that the hierarchical peer system, online peer context, and friendships play in driving information diffusion of negative peer relations among adolescents.