Resource smoothing: A cost minimization approach

From the available literature, there seems to be no defined approach to resource smoothing exercise except those attempted by Weist (1967, Management Science, 13, B359-B377) and Burgess and Killebrew (1962, Journal of Industrial Engineering, 13, 76-83). The aim of the smoothing exercise is to achieve optimal resource usage by avoiding high peaks and deep valleys in the project resource profile. The general approach has always been to move some activities with floats in the high peak regions to be started at a later date, and as this is done, the valleys will be filled to smooth the resource profile subject of course to time constraint. If this approach is followed as it is, it would be difficult to determine optimality especially when many resources are involved. A cost minimization approach is envisaged in the present study with no limitation on the number of resource inputs. In a situation where the resources are assumed to have the same value, the cost assigned to each of them should be similar. The method follows the general concept but with a difference; cost of the activity in question is considered. The exercise is continued until all the floats are exhausted. The optimum result would then be the one with the minimum cost profile. From examples used for the evaluation, the results obtained are comparable to those of the above two researchers, and some with better results in the majority of cases.     

Decision Support System of Truck Routing and Refueling: A Dual‐Objective Approach

The variable‐route vehicle‐refueling problem (VRVRP) is a variant of the network‐flow problem which seeks, for a vehicle traveling from origin s to destination d, both the route and the refueling policy (sequence of fuel stations to use between s and d) that jointly minimize the fuel cost of operating the vehicle. Commercial‐grade decision support systems that solve the VRVRP are widely used by motor carriers, but they provide heuristic solutions only. Exact methods are available from the academic side, but because they focus on minimizing costs, they tend to cut fuel costs in exchange for increased vehicle miles (which can increase fuel consumptions and pollutants emission). We propose a new approach to the VRVRP that allows carriers to jointly seek the two possibly conflicting goals; minimizing fuel cost and vehicle miles. Computational testing shows that our approach (i) outperforms the commercial software products in both goals, and (ii) finds solutions that require significantly less vehicle miles than those given by the exact method proposed in the academic literature, without incurring unacceptable increases in fuel cost.     

布什政府中东国际广播效能评析

为了缓解“9·11”事件后中东强烈的反关甚至仇美情绪，布什政府决定加大对中东的广播宣传。布什政府认为，从整体上讲，中东的媒体环境对美国是“不友好的”，甚至是“充满敌意的”；中东民众所接触到的有关美国的信息是“不真实的”，甚至是“被歪曲的”。这些“不真实”、“不可靠”的信息误导了中东民众，使他们对美国产生了“误解”和“仇恨”。正是基于这种逻辑，布什政府在“9·11”事件后不久很快建立起包括萨瓦电台、自由电视台、自由阿富汗电台等在内的中东广播网络，目的是宣传美国的外交政策，传播美国的价值观，舒缓中东民众对美国的敌意，增进中东民众对美国的好感。但是从2002年初至今的情况来看，布什政府对中东的广播宣传并没有达到预期的效果，其核心原因在于中东民众对美国中东政策的不满。     

局域网技术在计算机硬件实验室建设中的应用

本文介绍了把NOVELL网络应用于微机原理与接口技术等硬件实验中的方法与优势 ,以求能充分利用现有资源 ,改进计算机硬件实验教学的手段 ,提高硬件实验的教学效果 .     

Ranking terrorists in networks: A sensitivity analysis of Al Qaeda's 9/11 attack

All over the world, intelligence services are collecting data concerning possible terrorist threats. This information is usually transformed into network structures in which the nodes represent the individuals in the data set and the links possible connections between these individuals. Unfortunately, it is nearly impossible to keep track of all individuals in the resulting complex network. Therefore, Lindelauf et al. (2013) introduced a methodology that ranks terrorists in a network. The rankings that result from this methodology can be used as a decision support system to efficiently allocate the scarce surveillance means of intelligence agencies. Moreover, usage of these rankings can improve the quality of surveillance which can in turn lead to prevention of attacks or destabilization of the networks under surveillance.The methodology introduced by Lindelauf et al. (2013) is based on a game theoretic centrality measure, which is innovative in the sense that it takes into account not only the structure of the network but also individual and coalitional characteristics of the members of the network. In this paper we elaborate on this methodology by introducing a new game theoretic centrality measure that better takes into account the operational strength of connected subnetworks.Moreover, we perform a sensitivity analysis on the rankings derived from this new centrality measure for the case of Al Qaeda's 9/11 attack. In this sensitivity analysis we consider firstly the possible additional information available about members of the network, secondly, variations in relational strength and, finally, the absence or presence of a small percentage of links in the network. We also introduce a case specific method to compare the different rankings that result from the sensitivity analysis and show that the new centrality measure is robust to small changes in the data.     

The influence of network structures of Wikipedia discussion pages on the efficiency of WikiProjects

As a platform for discussion and communication, talk pages play an essential role in Wikipedia to facilitate coordination, sharing of information and knowledge resources among Wikipedians. In this work we explore the influence of network structures of these pages on the efficiency of WikiProjects. Project efficiency is measured as the amount of work done by project members in a quarter. The study uses the comments on WikiProject talk pages to construct communication networks. The structural properties of these networks are studied using ideas from social network theory. We develop three hypotheses about how network structures influence project effectiveness and examine the hypotheses using a longitudinal dataset of 362 WikiProjects. The evaluation suggests that an intermediate level of cohesion with a core of influential users dominating network flow improves effectiveness for a WikiProject, and that greater average membership tenure relates to project efficiency in a positive way. We discuss the implications of this analysis for the future management of WikiProjects.     

Gamers’ confidants: Massively Multiplayer Online Game participation and core networks in China

Through a survey of more than 18,000 participants in a Chinese Massively Multiplayer Online Game (MMOG), this study examines how the size and diversity of Chinese gamers’ core networks vary by individuals’ sociodemographic, socioeconomic and game-related characteristics. It represents the first study focusing exclusively on the gamer population and one of the most recent examining personal networks in contemporary China, home to over 560 million Internet users. We found that Chinese gamers have notably larger and more diverse core networks than those of major studies. Coplaying patterns and attachment to the game community contributed significantly to network size and diversity.     

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.     

试析新媒介环境下的网络问政

网络问政已经成为政府执政的重要补充方式,且作用日益显著。本文界定了网络问政的内涵,分析了网络问政的三种主要形式,并进而对政务微博的发展概况和运用中的关系把握做了尝试性探讨。