无线传感器的网络技术应用分析

无线传感器网络是近年来发展迅速的无线网络,与传统的无线网络相比具有更高的技术优势。本文介绍了无线传感器网络的主要特征和优势,通过与传统无线网络的技术比较分析了无线传感器的网络技术应用热点。     

Unleashing the Power of Networks: Shareholder Activism,Sustainable Development and Corporate Environmental Policy

In recent years, a new trend has emerged in which shareholder activists have formed networks to empower shareholders and magnify shareholder voices. This study explores the structural patterns and effectiveness of shareholder activism networks and shows how those networks affect corporate sustainability policies. We draw upon stakeholder influence theory, stakeholder network management theory and recent studies on activism networks to examine a shareholder activism network formed around environmental issues. The study found that (1) the structure of shareholder activist networks is largely driven by organizational attributes such as organization type, organizations’ human resources, media visibility and history; and (2) activist organizations with high centralities and eigenvector centralities enjoy more efficient results. This study contributes to our understanding of the business responses to shareholder demands on improving environmental performance and paves the way for future research on sustainable development through partnerships with shareholder networks. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment     

Planning rapid transit networks

Rapid transit construction projects are major endeavours that require long-term planning by several players, including politicians, urban planners, engineers, management consultants, and citizen groups. Traditionally, operations research methods have not played a major role at the planning level but several tools developed in recent years can assist the decision process and help produce tentative network designs that can be submitted to the planners for further evaluation. This article reviews some indices for the quality of a rapid transit network, as well as mathematical models and heuristics that can be used to design networks.     

基于成员组的局部信任模型研究

信任机制作为对等网络安全问题解决方案,在国际上得到广泛研究,并取得许多重要成果。文章分析了信任机制的特点、性质和组成,重点分析了一种P2P网络信任模型:基于成员组的局部信任模型,并给出下一步可能的发展方向。     

供应链二级分销网络的一种成本优化模型

提出了一种二级分销网络的成本优化的模型。模型研究了单个工厂的制造商和多个分销商组成的二级分销网络成本优化问题,把保证不发生缺货情况作为约束条件。综合考虑了订货成本、库存持有成本、运输成本和建立分销点和分销中心的成本,并给出了基于遗传算法的模型求解步骤。     

基于改进遗传算法的FIR数字滤波器的优化设计

提出了利用基于BP(Back Propagation)神经网络的遗传算法来设计FIR数字滤波器的方法。针对遗传算法很难实现全局最优和搜索速度比较慢的缺陷,提出了改进算法,该算法充分利用了遗传算法的全局搜索功能强和BP神经网络的搜索效率高,优化了搜索时间,提高了算法性能,对于解决大规模多极值优化问题特别有效。最后,以设计低通滤波器的实例验证算法的可行性。     

计算机信息技术在高校网络安全中的应用研究

网络已经成为高等教育的重要组成部分,然而高校的网络安全问题逐步呈现。因此提高计算机技术在高校网络安全中的应用是保证高校网络安全的基础。本文分析计算机技术在高校网络安全中的具体应用。     

How to Mend a Fragmented City: a Critique of ‘Infrastructural Solidarity'

Cities in Latin America in particular have been investing in new transportation networks such as bicycle systems, metros and bus rapid transit (BRT) technologies in recent years. These infrastructures are promoted as cures for trenchant social and spatial divisions as much as for traffic gridlock and vehicular pollution. This article unpacks the theory that infrastructures might mend cities that have been fragmented into disparate parts by uneven capitalist development. I argue that this ‘infrastructural solidarity' thesis relies on a troubled imagination—shared across urban design and strands of urban theory—that infrastructures are static, formal arrangements that concretize relations and enforce social cohesion or fragmentation. This article draws on qualitative research on the TransMilenio BRT system in Bogotá, Colombia, as well as on the work of Bruno Latour, suggesting that the political life of infrastructure is better revealed when such systems are understood as dense knots of shifting relations with complex temporalities. Arguments for the value of this type of actor‐network theory (ANT) reading often skew towards the esoteric, but the TransMilenio case shows how sorting through infrastructural ontologies actually matters in terms of how urbanists—academic and practicing—conceive of and work towards just and functional cities.     

如何做好GSM网络的维护与优化工作

GSM网络的维护工作是一个循环闭合的过程,其设计、工程建设、维护、优化工作的循环往复才能铸就优秀的无线网络。所以只有切实注重每个环节,才能把网络建设好、维护好。文章介绍了影响GSM网络的维护的因素,维护的措施,并阐述了维护和优化GSM网络的意义。     

Computing systemic risk using multiple behavioral and keystone networks: The emergence of a crisis in primate societies and banks

What do the behavior of monkeys in captivity and the financial system have in common? The nodes in such social systems relate to each other through multiple and keystone networks, not just one network. Each network in the system has its own topology, and the interactions among the system’s networks change over time. In such systems, the lead into a crisis appears to be characterized by a decoupling of the networks from the keystone network. This decoupling can also be seen in the crumbling of the keystone’s power structure toward a more horizontal hierarchy. This paper develops nonparametric methods for describing the joint model of the latent architecture of interconnected networks in order to describe this process of decoupling, and hence provide an early warning system of an impending crisis.     

WCDMA网络的规划及优化

WCDMA作为第三代移动通信的一个重要分支,其广泛应用建设已迫在眉睫。而我国WCDMA建设和优化的挑战面临着时间紧、规模大、优化艰、管理难的难题。而在网络建设的初期,前期的网络规划是关键因素,从源头上准备建设一个高质量、能提供多种类型业务、有竞争力的网络,是WCDMA网络规划的出发点。     

天津滨海新区物流基础设施网络优化研究

通过对物流基础设施及物流基础设施网络内涵的介绍，从天津滨海新区物流基础设施网络的发展现状出发，分析了目前物流基础设施网络建设中出现的问题，并从物流基础设施网络的结构、功能、规模和布局等方面提出了优化的对策和建议。     

CREDIBLY IDENTIFYING SOCIAL EFFECTS: ACCOUNTING FOR NETWORK FORMATION AND MEASUREMENT ERROR

Understanding whether and how connections between agents (networks) such as declared friendships in classrooms, transactions between firms, and extended family connections, influence their socio‐economic outcomes has been a growing area of research within economics. Early methods developed to identify these social effects assumed that networks had formed exogenously, and were perfectly observed, both of which are unlikely to hold in practice. A more recent literature, both within economics and in other disciplines, develops methods that relax these assumptions. This paper reviews that literature. It starts by providing a general econometric framework for linear models of social effects, and illustrates how network endogeneity and missing data on the network complicate identification of social effects. Thereafter, it discusses methods for overcoming the problems caused by endogenous formation of networks. Finally, it outlines the stark consequences of missing data on measures of the network, and regression parameters, before describing potential solutions.     

高职高专院校计算机网络专业实践教学的研究

本世纪是信息和知识经济迅速发展的世纪,随着计算机网络技术的日益普及和迅猛发展,计算机网络教育已经在社会的各个领域得到普及,不断推动着社会和经济的发展。社会对专业技术人才的要求越来越高,动手能力强,且熟练掌握计算机知识和网络系统设计、建设规划和维护是他们必备的素质。针对高职高专网络教育教学的特点,结合本人自身的教学体会以及计算机网络专业学生的实际就业情况,对实践性教学进行了深入研究,总结了一些适用性较强的教学方法。     

高速铁路CPⅢ控制网置平处理结果分析

目前(边角)后方交会控制网已成为构建高速铁路CPⅢ网的主要形式,但所采用的数据处理方法一直采用经典的约束网平差,未采用先进的控制网置平技术等测量数据处理方法。经过中铁八局集团有限公司和西南交通大学的共同努力,研制出了和国外同类软件一样具有控制网置平功能的CPⅢ网数据平差软件包(WZTCS)。本文根据WZTCS的CPⅢ网置平功能特点,利用CPⅠ、CPⅡ和CPⅢ控制网仿真试验和在建客运专线的工程实例,证实了采用先进的控制网置平技术比采用经典的约束网平差,CPⅢ控制网的精度和平顺性更高。     

Co-ordination and integration mechanisms to manage logistics processes across supply networks

Literature on supply chain management (SCM) emphasises the importance of co-ordination and integration mechanisms to manage logistics processes successfully across supply networks. This requires managers to (1) know the driver variables that must be addressed, since they determine how such processes can be designed and managed; and (2) understand how co-ordination and integration mechanisms interact with such variables and—as a consequence—with logistics processes. The paper addresses the second issue, as it tries to explain how logistics processes can be structured and controlled across supply networks by leveraging co-ordination and integration mechanisms, with consequences for strategic and operational choices for both the individual companies and the whole supply network. This issue has been investigated by analysing three case-studies of SCM interventions on logistics processes across different supply networks, involving central firms as well as several suppliers and customers.     

Solving the generalized transportation problem

This paper advocates a mathematical programming approach for solving the classical transportation problem generalized to include non-linear demand and supply functions and non-linear transport costs. Such an approach is made possible by the recent public availability of a powerful optimizing system called MINOS, assembled for the solution of large programming problems for which the constraint set is linear and spatial. Primal and dual program formulations for this generalized transportation problem are set out in the paper, and brief computational experience with the software system in solving several illustrative problems is recorded.     

无线传感器网络功率控制技术综述

随着物联网在中国的发展,无线传感器网络(WSN)已成为当今的一个研究热点,由于WSN是一个能量受限网络,需要降低能量消耗以延长网络的正常使用寿命,功率控制技术正是降低其能量消耗的重要手段。为充分了解WSN功率控制技术研究现状,介绍了网络的功率控制问题,分析了无线传感器网络的功率控制技术,说明了研究基于跨层设计的功率控制技术的必要性。     

Multi-subject stochastic blockmodels with mixed effects for adaptive analysis of individual differences in human brain network cluster structure

Recently, there has been a renewed interest in the class of stochastic blockmodels (SBM) and their applications to multi-subject brain networks. In our most recent work, we have considered an extension of the classical SBM, termed heterogeneous SBM (Het-SBM), that models subject variability in the cluster-connectivity profiles through the addition of a logistic regression model with subject-specific covariates on the level of each block. Although this model has proved to be useful in both the clustering and inference aspects of multi-subject brain network data, including fleshing out differences in connectivity between patients and controls, it does not account for dependencies that may exist within subjects. To overcome this limitation, we propose an extension of Het-SBM, termed Het-Mixed-SBM, in which we model the within-subject dependencies by adding subject- and block-level random intercepts in the embedded logistic regression model. Using synthetic data, we investigate the accuracy of the partitions estimated by our proposed model as well as the validity of inference procedures based on the Wald and permutation tests. Finally, we illustrate the model by analyzing the resting-state fMRI networks of 99 healthy volunteers from the Human Connectome Project (HCP) using covariates like age, gender, and IQ to explain the clustering patterns observed in the data.