An access network design problem with end-to-end QoS constraints

In this paper, we present an access network design problem with end-to-end quality of service (QoS) requirement. The problem can be conceptualized as a two-level hierarchical location-allocation problem on the tree topology with nonlinear side constraints. The objective function of the nonlinear mixed integer programming model minimizes the total cost of switch and fiber cable, while satisfying demand within the prescribed level of QoS. By exploiting the inherent structure of the nonlinear QoS constraints, we develop linearization techniques for finding an optimal solution. Also, we devise an effective exact optimal algorithm within the context of disjunctive constraint generation. We present promising computational results that demonstrate the effectiveness of the proposed solution procedure.     

Transient detailed balance and product form for reaction networks

This paper explores the boundary of the set of reaction networks that have an exact transient (truncated) multidimensional Poisson or product-form distribution for the number of particles of different types. Motivated by the birth–death process, we introduce the notions of transient detailed balance and delay functions, and use these notions to obtain the novel transient product-form distribution in a coagulation-fragmentation process for polymers with a tree-like structure from that of the pure coagulation process.     

充分利用网络技术全面提高会计控制质量

e7T中华财会网网络技术的发展对企业内部会计控制产生了深远的影响,文章从网络环境下内部会计控制呈现的新特点着手,分析了网络环境下内部会计控制系统所面临的风险,对存在的问题及其成因作了尝试性的探讨,提出了完善、加强内部会计控制的建议,以期达到提高网络环境下内部会计控制质量的目的。     

Connecting for success: Egocentric network types among underrepresented minority students at college

This study investigates the egocentric networks of underrepresented minority students. Adjustment to college for underrepresented minority students often means balancing between the origin (i.e., low-status family) and host (i.e., academic) environments, requiring students to develop different coping strategies. The analysis included 124 Roma university students. We employed the contact diary method and the EgoNet program for mapping students’ egocentric networks. We explored classification among egocentric networks by cluster analysis based on the network proportion of the origin, fellow, and host groups. Three clusters were distinguished. The Host-based cluster proved to be the most advantageous, while the Balancing cluster appeared to be the most disadvantageous in terms of network resources, well-being, and trust. Partners’ ethnicity and educational attainment showed a strong connection with cluster membership. Our results highlight that small fellow communities can successfully interconnect the origin and host groups in students’ egocentric networks.     

How Moroccan‐Dutch parents learn in communities of practice: Evaluating a bottom‐up parenting programme

Research shows that top‐down‐designed parenting programmes do not always meet the needs of postmigration parents. Bottom‐up programmes by migrant organizations hold a promise to fill this gap; however, research about these programmes and appropriate evaluation methodologies is scarce. Drawing upon Wenger's ( 2010 ) “communities of practice,” this paper explores an alternative perspective on parenting programme evaluation. Findings are presented from a study looking into social learning processes of postmigration parents who participated in a bottom‐up programme about raising teenagers in urban areas. Using an ethnographically inspired method combined with a preprogramme and postprogramme design, 115 Moroccan‐Dutch mothers and fathers from 15 programme groups participated. Results show that the programme provided a social learning space in which parents used themselves as resources to learn collectively about parenting. Moreover, parents consciously engaged in learning interactions across learning spaces stretched into their social networks. These analyses showed how parents' development of “learning citizenship” (Wenger, 2009 ) provides us with insight in collective learning dimensions present in a bottom‐up parenting programme, which is often not included in evaluation studies. Implications for practitioners as facilitators of parents' collective learning are presented.     

社会资本与身心健康--概念辨析基础上的关系再检验

社会资本与健康研究领域存在核心概念界定不清与理论解释欠缺两大不足。文章在社会网络的视角下对社会资本、社会凝聚和社会支持三个相互杂糅的概念进行辨析区分，并在此基础上以调查数据实证检验了社会资本对身心健康的作用效果与影响机制。结果显示，在控制社会凝聚和社会支持作用的条件下，社会资本依然对自评健康和心理健康存在显著的独立影响，但其对两种健康在影响因素和影响方向上呈现一些差异。其中，网络规模和网络顶端对自评健康和心理健康都具有显著的正向作用，而心理健康同时还受到网络差异的负向影响。从这个角度而言，社会资本对个体身心健康的影响并不必然是积极正向的。     

Analytic strategies for longitudinal networks with missing data

Missing data are often problematic when analyzing complete longitudinal social network data. We review approaches for accommodating missing data when analyzing longitudinal network data with stochastic actor-based models. One common practice is to restrict analyses to participants observed at most or all time points, to achieve model convergence. We propose and evaluate an alternative, more inclusive approach to sub-setting and analyzing longitudinal network data, using data from a school friendship network observed at four waves (N = 694). Compared to standard practices, our approach retained more information from partially observed participants, generated a more representative analytic sample, and led to less biased model estimates for this case study. The implications and potential applications for longitudinal network analysis are discussed.     

网络文化背景下汉语言的变异探析

随着互联网的普及,现在中国已经进入了网络时代,现在的人们以及各行各业都离不开网络,它与人们的生活息息相关,尤其现在的年轻人,网络已经成为他们生活中不可缺少的一部分。由于网络的及时性,更多的人已经开始习惯于从网络上获取信息。除了从网络上获取信息,人们还可以在网上交友,信息分享和进行其他的网络活动。网络活动的增多,网络语言也开始繁荣起来。为了适应网络的特殊环境,网络语言在汉语言的词汇、语法、发音和构成上都发生了很大的变异。本文将对网络语言的产生、发展以及网络语言对汉语言产生的影响进行分析。     

Testing the validity of social capital measures in the study of information and communication technologies

Social capital has been considered a cause and consequence of various uses of new information and communication technologies (ICTs). However, there is a growing divergence between how social capital is commonly measured in the study of ICTs and how it is measured in other fields. This departure raises questions about the validity of some of the most widely cited studies of social capital and ICTs. We compare the Internet Social Capital Scales (ISCS) developed by Williams [2006. On and off the ’net: scales for social capital in an online era. Journal of Computer-Mediated Communication, 11(2), 593–628. doi: 10.1111/j.1083-6101.2006.00029.x] – a series of psychometric scales commonly used to measure ‘social capital’ – to established, structural measures of social capital: name, position, and resource generators. Based on a survey of 880 undergraduate students (the population to which the ISCS has been most frequently administered), we find that, unlike structural measures, the ISCS does not distinguish between the distinct constructs of bonding and bridging social capital. The ISCS does not have convergent validity with structural measures of bonding or bridging social capital; it does not measure the same concept as structural measures. The ISCS conflates social capital with the related constructs of social support and attachment. The ISCS does not measure perceived or actual social capital. These findings raise concerns about the interpretations of existing studies of ‘social capital’ and ICTs that are based on the ISCS. Given the absence of measurement validity, we urge those studying social capital to abandon the ISCS in favor of alternative approaches.     

高端装备制造业知识网络有效性影响因素分析

分析影响高端装备制造业知识网络有效性的五个因素,构建知识网络有效性模型并进行仿真分析,得出结论:企业为提高知识吸收能力和知识释放意愿所做投入在一定范围内可以提升知识网络有效性,投入超过一定值后,这种提升作用不再明显;企业较高的知识水平、企业间良好的合作关系与适当的知识势差可以提高知识网络有效性,并根据仿真结果提出相关建议。