“十三五”电力规划中新能源大规模外送的安全稳定问题

"十三五"期间国家科学推进远距离、大容量电力外送,特高压快速发展,《电力发展"十三五"规划》中提及的东北扎鲁特—山东及华北胜利—锡盟特高压外送工程等都为重要的电力外送通道,规划中的电网格局将出现大规模汇集电力通过直流送出、大规模新能源接入及交直流并列运行等特征,直流输送容量的提升将给电网安全稳定带来新的挑战和问题。依托国家电网仿真中心,从特高压交直流大规模电力外送的暂态稳定性方面进行安全稳定校核,剖析大规模电力外送给电网所带来的一系列新问题,提出可能的应对措施,有效解决国家电网"十三五"规划电网中大规模电力外送通道面临的主要安全稳定问题。     

弹药与民爆通用生产技术与装备现状

为提高弹药与民爆行业的自动化生产水平,减少操作人员,提高产品质量,对弹药与民爆通用生产技术 与装备现状进行研究。介绍弹药与民爆行业火工品、称量、压装、安全、安全检测与故障自诊断等通用生产技术, 以及高精度动态称量机、防爆电伺服压机、全自动柔性旋压机、循环式射孔弹生产线等关键技术装备在弹药与民爆 行业的应用发展,提出关于弹药与民爆行业发展的设想。     

R290替代R22的解决方案综述及展望

作为一种兼顾环保、节能的制冷剂,R290与R22的标准沸点、凝固点、临界点等基本物理性质非常接近,具备替代R22的基本条件,拥有广阔的应用前景和市场价值。但由于其与空气混合能形成易燃易爆混合物,存在重大安全隐患,抑制了R290制冷产品的推广和应用。本文通过总结国内外学者对改善R290制冷系统所做的研究,分析了R290替代R22存在的弊端,对提高R290系统安全性的解决方案进行综述,并根据最新研究,分别从减少制冷剂灌注量、间接使用R290以及加入阻燃剂方面对今后的研究方向作出展望,以期推广R290在制冷产品中的使用。     

中国水资源研究热点及发展趋势

目前水资源问题已经成为制约中国经济社会可持续发展的重要因素。运用中国知网“指数”功能,综述近年来中国国家自然科学基金和社会科学基金等资助的146篇关于水资源研究相关文献,归纳出5个水资源热点研究领域：水资源承载力、水资源安全、水资源生态、虚拟水和水足迹,对其代表理论、评价方法、主要研究领域和研究发展方向进行综述。总结出中国水资源研究发展的3个趋势：1）加强水资源领域交叉融合研究;2）在水资源安全、水生态服务功能研究等领域注重构建完整的研究框架;3）在研究成熟的领域加强评价方法创新。     

考虑元件综合重要度的电网安全性风险评估方法

从系统学角度出发,综合考虑系统中元件的结构属性、状态属性及社会属性,提出一种考虑元件综合重要度的电网安全性风险评估方法。综合元件结构重要度因子模型与元件状态灵敏度因子模型构建元件综合重要度模型,该模型克服了传统风险评估方法中对于不同元件的重要度无法表征的不足;综合考虑电网结构与状态,建立表征电网潮流分布均衡性与负荷损失的严重度模型,完善安全性风险评估指标体系。仿真结果表明,相较于传统方法,该方法对电网N-1故障风险排序更为合理,对N-k故障序列分级风险辨识度更高。     

燃煤电厂输煤程控频繁故障的应对策略及安全分析

针对某火电厂输煤程控频繁故障,对网络结构改造、控制方式进行优化,极大地提高了输煤程控系统的抗干扰能力和安全性,彻底解决了原来由于通讯频繁中断,尤其受环境温度和电磁干扰而造成的皮带异常停止和失去保护的不安全隐患,为火电厂输煤控制及其它辅助控制系统通讯异常的处理提供一些借鉴。     

A data privacy protective mechanism for wireless body area networks

As an important branch of wireless sensor networks, wireless body area networks (WBAN) has attracted widespread attention in various fields because of its portability and mobility. However, because much of the data collected by WBAN are related to personal information of the user, the sensitive private data may be at risk of leakage or malicious modification in the actual process of application and deployment. In order to assure the security and privacy of user's data in the environment of WBAN, this paper presents a Data Privacy Protective Mechanism for WBAN. In order to secure data and secure transmission, this mechanism combines symmetric key with an asymmetric key to transmit user's data. Then, it cuts and reorganizes the data in the process of transmission to better capture defense and the attacks of the nodes. Ultimately transmits the user's data securely under the condition that the data collected by the nodes are confidential and secure. Copyright © 2015 John Wiley & Sons, Ltd.     

The BER analysis of OFDMA and SC‐FDMA under pilot‐assisted channel estimation and pilot jamming in rayleigh slow‐fading channel

In this paper, the authors derived the analytical bit error rate expressions for orthogonal frequency division multiple access and single‐carrier frequency‐division multiple access (SC‐FDMA) in Rayleigh slow‐fading channel for binary phase‐shift keying/quadrature phase‐shift keying/16‐quadrature amplitude modulations under pilot jamming and pilot symbol‐assisted channel estimation. Beginning with the bit error rate analysis from the general case of pilot symbol‐assisted channel estimation technique in Rayleigh slow‐fading channel, the expressions are first modified for different modulations and then further customized to account for the Zero‐Forcing equalization in frequency or time direction with application respectively to orthogonal frequency division multiple access or SC‐FDMA without and with pilot jamming. Piecewise‐linear interpolation is used for its simplicity. The simulation results match perfectly with the theoretical predictions except for some discrepancies with SC‐FDMA, which imply that the generalized equations developed here have to be further modified to account for system‐specific features like discrete Fourier transform precoding for SC‐FDMA. Copyright © 2016 John Wiley & Sons, Ltd.     

IP2DM: integrated privacy‐preserving data management architecture for smart grid V2G networks

With the development of battery vehicles, vehicle‐to‐grid (V2G) networks are becoming more and more important in smart grid. Although battery vehicles are environmentally friendly and flexible to use two‐way communication and two‐way electricity flow, they also raise privacy‐preservation challenges, such as location and movement privacy. On the one hand, utility companies have to monitor the grid and analyze user data to control the power production, distribution, scheduling, and billing process, while typical users need to access their data later online. On the other hand, users are not willing to provide their personal data because they do not trust the system security of the utility companies where their data stored, and it may potentially expose their privacy. Therefore, in this paper, we study data management of V2G networks in smart grid with privacy‐preservation to benefit both the customers and the utility companies. Both data aggregation and data publication of V2G networks are protected in the proposed architecture. To check its security, we analyze this architecture in several typical V2G networks attacks. We conduct several experiments to show that the proposed architecture is effective and efficient, and it can enhance user privacy protection while providing enough information for utility companies to analyze and monitor the grid. Copyright © 2016 John Wiley & Sons, Ltd.     

A k‐means clustering‐based security framework for mobile data mining

Data mining is a process of digging data sets from large data‐bases, especially for use to improve the operation efficiency of a company, institution, or an organization. With the increasing cases of cyber and other computer‐related crimes, computer and mobile data security has become a matter of concern, secure, and non‐contaminated data is very important for data mining to improve the performance of a system. This paper proposes a system framework that is able to collect information and then be able to generate alerts in real time. The proposed scheme is then simulated using the K‐means clustering algorithm, which is one of the most popular clustering algorithms to determine the efficiency and the accuracy of the proposed scheme. The paper concludes by proposing further improvements to be undertaken on the proposed system to improve its efficiency and accuracy. Copyright © 2017 John Wiley & Sons, Ltd.