选择千兆位以太网还是ATM

作为一种新技术 ,千兆位以太网技术在具有强大生命力的同时 ,也有着其不成熟的一面 ,在今后的高速联网技术市场上它与ATM(AsynchronusTransferMode)哪种技术将独执牛耳 ,目前还很难断言 本文从几个方面来比较一下千兆位以太网技术和ATM技术的各自特点     

A network centrality bias: Central individuals in workplace networks have more supportive coworkers

Combining the results of two empirical studies, we investigate the role of alters’ motivation in explaining change in ego’s network position over time. People high in communal motives, who are prone to supportive and altruistic behavior in their interactions with others as a way to gain social acceptance, prefer to establish ties with co-workers occupying central positions in organizational social networks. This effect results in a systematic network centrality bias: The personal network of central individuals (individuals with many incoming ties from colleagues) is more likely to contain more supportive and altruistic people than the personal network of individuals who are less central (individuals with fewer incoming ties). This result opens the door to the possibility that the effects of centrality so frequently documented in empirical studies may be due, at least in part, to characteristics of the alters in an ego’s personal community, rather than to egos themselves. Our findings invite further empirical research on how alters’ motives affect the returns that people can reap from their personal networks in organizations.     

Risk Analysis of Safety Service Patrol (SSP) Systems in Virginia

The transportation infrastructure is a vital backbone of any regional economy as it supports workforce mobility, tourism, and a host of socioeconomic activities. In this article, we specifically examine the incident management function of the transportation infrastructure. In many metropolitan regions, incident management is handled primarily by safety service patrols (SSPs), which monitor and resolve roadway incidents. In Virginia, SSP allocation across highway networks is based typically on average vehicle speeds and incident volumes. This article implements a probabilistic network model that partitions “business as usual” traffic flow with extreme‐event scenarios. Results of simulated network scenarios reveal that flexible SSP configurations can improve incident resolution times relative to predetermined SSP assignments.     

Random Accessibility as a Parallelism to Reliability Studies on Simple Graphs

ABSTRACT

Graphs are classified according to the numbers of vertices and edges they contain. For simple graphs a concept of accessibility is defined and its relation to the graph reliability problem is investigated. Exact results are derived for special subclasses of bipartite and tripartite graphs in relation to accessibility. Several conjectures on the relation of accessibility and all-terminal reliability are numerically illustrated without proof.     

系统症结辨识的模糊分析与应用

本文基于模糊因果网络分析,提出了系统症结辨识的一种新思路,实例研究了吉林省轻工业发展现状的主要症结所在．     

Who Cares About Your Big Day? Impact of Life Events on Dynamics of Social Networks

With online social networking having revolutionized the way in which individuals communicate and interact with each other, there is heightened research interest in the dynamics of social networks. This article seeks to contribute to this stream of research by addressing the key question of the impact of major life events, such as getting married or graduating from college, on social network evolution. Consistent with prior studies on the evolution of individuals’ social networks, we specifically focus on two key attributes of an individual's network: indegree of ties and relational embeddedness. By longitudinally analyzing the network activities of a large‐scale online social network, we find that the indegree of ties increased significantly following a major life event, and that this impact was stronger for more active users in the network. Interestingly, we also find that the broadcast of major life events served to revive dormant ties as reflected by a decrease in embeddedness following a life event. We also found that one‐time life events such as weddings had a greater impact than recurring life events such as birthdays on the evolution of a user's social network. From a research perspective, our study contributes to existing research by focusing on a user's communication network as opposed to friendship network and by emphasizing how exogenous life events add a different dimension to user communication patterns. The importance of life events on social network evolution has important implications for practice as well by providing insights to advertisers as well as to social networking sites.     

Adaptive sampling without replacement of clusters

In a common form of adaptive cluster sampling, an initial sample of units is selected by random sampling without replacement and, whenever the observed value of the unit is sufficiently high, its neighboring units are added to the sample, with the process of adding neighbors repeated if any of the added units are also high valued. In this way, an initial selection of a high-valued unit results in the addition of the entire network of surrounding high-valued units and some low-valued “edge” units where sampling stops. Repeat selections can occur when more than one initially selected unit is in the same network or when an edge unit is shared by more than one added network. Adaptive sampling without replacement of networks avoids some of this repeat selection by sequentially selecting initial sample units only from the part of the population not already in any selected network. The design proposed in this paper carries this step further by selecting initial units only from the population, exclusive of any previously selected networks or edge units.     

增强高校网络思想教育实效性的思考

电脑互联网络风靡全球，网络对大学生成长提供有利条件的同时，也对他们的成长造成诸多不利影响，提高网络思想教育的实效性成为高校思想教育工作的重要课题。改进网络思想教育的方式、理念、机制，提高学校思想教育工作者开展网络思想教育能力，是当前增强网络思想教育时效性的重要着眼点。     

Mixing patterns between age groups in social networks

We present a method for estimating transmission matrices that describe the mixing and the probability of infection between age groups. Transmission matrices can be used to estimate age-dependent forces of infection in age-structured, compartmental models for the study of infectious diseases. We analyze the social network generated by the synthetic population of Portland and extract mixing patterns. Our results show that the mixing within the population consists of two groups, children and adults. Children interact most frequently with other children close to their own age, while adults interact with a wider range of age groups and the durations of typical adult contacts are shorter than typical contacts between children. Furthermore, the transmission matrix shows that children are more likely to acquire infection than adults.