PMU based voltage security assessment of power systems exploiting principal component analysis and decision trees

The need for feature selection and dimension reduction is felt as a fundamental step in security assessment of large power systems in which the number of features representing the state of power grids dramatically increases. These large amounts of attributes are not proper to be used for computational intelligence (CI) techniques as inputs, because it may lead to a time consuming procedure with insufficient results and they are not suitable for on-line purposes and updates.This paper proposes a combined method for an online voltage security assessment in which the dimension of the token data from phasor measurement units (PMUs) is reduced by principal component analysis (PCA). Then, the features with different stability indices are put into several categories and feature selection is done by correlation analysis in each category. These selected features are then given to decision trees (DTs) for classification and security assessment of power systems.The method is applied to 39-bus test system and a part of Iran power grid. It is seen from the results that the DTs with reduced data have simpler splitting rules, better performance in saving time, reasonable DT error and they are more suitable for constant updates.     

浅谈中型企业IT运维管理

文章阐述了建设一支适合本企业IT运维的专业队伍,通过应用IT技术掌控运维队伍,使IT运维业务正常、有序、高效开展的思路,为生产管理服务,提供一个安全、可靠、高效、快捷的信息网络平台。     

基于系统权变理论的高校科研团队模式研究

高校科研团队建设已成为全面提高高校科研工作水平的重要环节,日益成为科学研究的基本组织形式。本文从＂投入—转化—产出＂的视角对高校科研团队的组织系统的运行机理、内外部因素和核心（动力）因素进行了较详尽的剖析,然后运用组织系统权变理论构建了线性模式、星型模式、平行模式、联邦模式、分布模式和虚拟模式共六种不同的高校科研团队组织模式,对高校科研团队建设的理论与实践有着一定的理论价值和现实意义。     

权变理论对留学生教学管理及其培养模式的启发

从权变理论的特性这一独特视角,分析留学生教学管理及其培养模式中出现的问题,并借用权变理论提出不同类型留学生教学管理机构模式下的培养模式,提出在留学生教育的规模、层次等方面实现分类教学、因材施教、按需教学的方案,解决留学生教育发展不同阶段的管理问题,逐渐完善留学生教育管理体系.     

新型学校预警系统在山洪灾害防治项目中的应用

我国山洪预报预警系统的技术研究工作开展较晚,当下山洪、泥石流、滑坡等山地灾害频发,对人民群众的安全和经济的发展都产生了极大的影响。本文在这样的背景之下,探讨了学校山洪预警系统的技术应用问题,分别从系统构成、技术要求和实现功能等方面加以论述,为学校山洪预警系统的建设提供了很好的指导。该系统具有自动接收、发布、传递水文气象和地质灾害信息,提供各学校节点实时水文气象数据、山洪预警信息、灾害应急预案、校内在册师生人员资料登记以及通知公告等数据信息的发布等功能。在实际使用中,性价比高,实用性强,具有较大的社会效益和经济效益。     

Complementary Effects of Information Technology Investment on Firm Profitability: The Functional Forms of the Complementarities

Abstract

This paper focuses on developing economic theory on the interrelation between information technology investment components. Three functional forms to model the joint effects between components of investment on firm accounting profitability are identified and empirically tested. The results suggest that the complementarities between components of IT investment can be best modeled by using the multiplicative functional forms, providing a framework to model the joint effects of different factors that impact firm profitability.     

实时预想事故自动选择算法

为了加快在线安全评定的速度,避免预想事故选择中的遮蔽现象。本文提出了一种能满足实时运行要求的实时预想事故自动选择算法,并提出了一种双机并行循环实时控制模型和三种基于事故链的性能指标,从而可以随着系统运行情况的变化自动形成预想事故序列表,使得运行人员随时了解这些事故对于系统安全运行影响的相对严重性．在此基础上,用ＦＯＲＴ－ＲＡＮ－７７语言编制并在ＷＡＸ／ＶＭＸ—７５０小型机调试通过了ＲＴＣＡＣＳ实时在线运行程序,通过对ＩＥＥＥ－１４节点和ＩＥＥＥ—３０节点实验系统进行计算,获得了满意的结果,表明本算法是一种切实可行的提高在线安全评定工作速度的方法。     

Board-Level Information Technology Governance Effects on Organizational Performance: The Roles of Strategic Alignment and Authoritarian Governance Style

ABSTRACT

We report on two empirical studies that explore key factors that help translate information technology governance by the board of directors into organizational performance. The first study shows that strategic alignment partially mediates the effect of board-level information technology governance on performance. The second study demonstrates that authoritarian governance style negatively moderates the effect of board-level information technology governance on performance. Together, these studies open up the black box between board-level information technology governance and organizational performance.     

构建校园网络安全保障体系

该文分析了校园网络环境的特殊性及校园网络安全管理的现状,指出了建立校园网络安全管理技术体系的途径,探讨了校园网络应急响应组的建立,确立了应急响应组的职能及响应机制,为构建校园网络安全保障体系提出了全方位的安全策略。     

完善库什塔依水电工程的安全体系 树立绿色环保示范电站新形象

库什塔依水电工程建设中始终把安全生产工作放在首位,以"完善大安全管理体系,夯实安全管理基础,打造流域开发绿色环保示范新形象"为目标,坚持"安全第一,预防为主、综合治理"的工作方针和"以人为本"的管理理念,采取多项措施,建设流域开发绿色环保示范电站新形象。自工程开工以来,未发生任何安全伤亡事故,实现了安全生产"零事故"的目标。