Distributed Time Synchronization in Wireless Sensor Networks via Second-Order Consensus Algorithms     

吴杰  白煜  张立毅 《天津大学学报(英文版)》2015,(2):113-121

This paper proposes a distributed second-order consensus time synchronization, which incorporates the second-order consensus algorithm into wireless sensor networks. Since local clocks may have different skews and offsets, the algorithm is designed to include offset compensation and skew compensation. The local clocks are not directly modified, thus the virtual clocks are built according to the local clocks via the compensation parameters. Each node achieves a virtual consensus clock by periodically updated compensation parameters. Finally, the effectiveness of the proposed algorithm is verified through a number of simulations in a mesh network. It is proved that the proposed algorithm has the advantage of being distributed, asymptotic convergence, and robust to new node joining.  相似文献   

Effect of Mn and Ni on microstructure and impact toughness of submerged arc weld metals     

杨立军  王会超  张智  张津  孟宪群  黄世明  白璆熠 《天津大学学报(英文版)》2015,21(6):562-566

The influences of Mn and Ni contents on the impact toughness and microstructure in the weld metals of high strength low alloy steels were studied. The objective of this study was to determine the optimum composition ranges of Mn and Ni to develop welding consumables with better resistance to cold cracking. The results indicated that Mn and Ni had considerable effect on the microstructure of weld metal, and both Mn and Ni promoted acicular ferrite at the expense of proeutectoid ferrite and ferrite side plates. Varying Ni content influenced the Charpy impact energy, the extent of which depended on Mn content. Based on the properties and impact resistance, the optimum levels of Mn and Ni were suggested to be 0.6%—0.9%,, and 2.5%—3.5%, respectively. Additions beyond this limit promoted the formation of segregation structures and other microstructural features, which may be detrimental to weld metal toughness.  相似文献   

中小学教师信息技术应用能力现状及培训建议   总被引：1，自引：0，他引：1  

张屹  马静思  周平红  范福兰  白清玉 《中国电化教育》2015,(1)

信息技术能力已成为信息化社会教师必备的专业能力,2014年6月,教育部颁布了《中小学教师信息技术应用能力标准(试行)》,开启了中小学教师新一轮信息技术应用能力提升培训。为了了解现阶段中小学教师信息技术应用能力水平,为能力提升培训的实施提供依据。该文以湖北、河南、安徽和广西四个省市中35个市区的414名中小学教师为调研对象,从标准的角度对其信息化应用能力现状开展较为全面的调研。结果表明中小学教师应用信息技术优化课堂教学能力的达标情况优于转变学习方式的能力。根据测评结果对中小学教师信息应用能力培训提出建议,也为我国推进信息化环境下教师队伍的建设提供借鉴。  相似文献   

英语教学中的“熏染”     

Bai Hua 《佳木斯教育学院学报》2015,(4)

英语学习方法很多,教学方法很多。本文不是想颠覆传统和成型的模式方法,而是从英语教学实践中得出的一种切实有用的方法,即"熏染",并依据"熏染"的原理,提出熏染的四个基本原则:持久性、恒温性、渐进性和重复性;提出熏染的五个方法:情景熏染、故事熏染、动作熏染、歌曲熏染、游戏熏染法;提出熏染的两个方式:自我渐染、相互渐染;并说明两个主义事项,一个是忌讳重视语法规范,提倡淡化语法;另一个是忌讳急功近利,强调长时间熏染。给目前的英语教学和英语学习提供一些有意义的方法途径。  相似文献   

全球价值链视角下经济失衡再分析     

白宇飞  孙俊新  陈建 《教学与研究》2015,(5)

在综述全球经济失衡影响因素的基础上,本文提出基于要素的价值链分工是造成本轮经济失衡规模庞大、持续时间长的决定因素.全球价值链影响经济失衡的机制包括:产业结构的调整、贸易统计向增加值核算转化的内在要求和贸易利得的内涵及决定因素的变化.金融危机之后各国采取的再平衡政策缓解了失衡的规模,但造成失衡的根本性因素没有变化,未来全球经济失衡仍可能加剧.  相似文献   

语言中的“反”性别歧视     

白乙静 《海外英语》2015,(6)

语言是社会的镜子,同样也随着时代的脚步而逐步更新,它过滤了违背时代潮流的“旧语”,也推出了顺应时代潮流的“新语”。而语言性别歧视话题几经斗争和演变,也都将会在语言这面镜子中得到修正和完善。传统上人们总是片面地认为性别歧视语言主要针对女性,而忽视了对男性的语言歧视;并且,既然性别歧视语言是在历史发展中产生的,那么也必然会随着历史发展而演变。因此,该文从相反的视角,提出“反”性别歧视---一方面研究女性在语言歧视中的“反抗”,另一方面也探究女性“反过来”针对男性的歧视。  相似文献   

A defensive mindset: A pattern of social information processing that develops early and predicts life course outcomes     

Kenneth A. Dodge  Yu Bai  Jennifer Godwin  Jennifer E. Lansford  John E. Bates  Gregory S. Pettit  Damon Jones 《Child development》2022,93(4):e357-e378

The hypothesis was tested that some children develop a defensive mindset that subsumes individual social information processing (SIP) steps, grows from early experiences, and guides long-term outcomes. In Study 1 (Fast Track [FT]), 463 age-5 children (45% girls; 43% Black) were first assessed in 1991 and followed through age 32 (83% retention). In Study 2 (Child Development Project [CDP]), 585 age-5 children (48% girls, 17% Black) were first assessed in 1987 and followed through age 34 (78% retention). In both studies, measures were collected of early adverse experiences, defensive mindset and SIP, and adult outcomes. Across both studies, a robust latent construct of school-age defensive mindset was validated empirically (comparative fit index = .99 in each study) and found to mediate the impact of early child abuse (38% in FT and 29% in CDP of total effect) and peer social rejection (14% in FT and 7% in CDP of total effect) on adult incarceration.  相似文献   

农产品关税配额管理改革对我国粮食安全的影响及对策分析     

王文涛  白银瑞 《常州大学学报(社会科学版)》2022,23(2):9-18

  相似文献   

Gabor传递函数相似性测度图像质量评价算法     

施明登  姚江河  白铁成 《科技通报》2014,(10)

数字图像在压缩和融合等处理中会产生退化效应,当前对图像退化中质量评价指标如均方误差(MSE),峰值信噪比(PSNR)等不能有效反映图像在退化过程中传递性能,而只是单纯计算图像之间灰度值差异,对图像质量评价不准。提出一种利用Gabor传递函数相似性测度为评价指标的图像质量评价算法,采用图像的亮度、对比度和结构相似度为场景结构基准特征,设计Gabor传递函数。通过双正交滤波器得到Gabor传递函数相似性测度,该指标能有效反映图像退化演变过程中的传递性能,合理评价参考图像和失真图像质量。仿真实验表明,利用Gabor传递函数相似性测度指标评价图像质量,能准确反映图像失真等级,在几乎所有失真类型上都能有较满意的结果,评价结果比较稳定。  相似文献   

辽宁省农村农业信息化门户网站平台建设研究     

白玲王霜李鸥等 《现代情报》2014,34(2):72-75,81

辽宁农业信息化网站平台基于现代农业的发展需求,结合辽宁地区农业发展现状,以标准化、统一化、科学化为依据,从网站的体系结构、功能模块设计和数据库的设计等方面提出了本地区农业信息网站建设总体思路、前后台功能管理及网站信息资源建设内容,为进一步开展农业信息网站的建设提供参考。  相似文献