Characterization of ZBGAN glasses

The physical and electrical properties of a ZrF₄-BaF₂-GdF₃-AIF₃-NaF (ZBGAN) glass have been studied. The addition of NaF increases the glass-forming ability of the base composition glass yet does not degrade the optical characteristics. The viscosity decreased with increasing NaF, suggesting that the increased glass-forming ability was due to the confusion principle. The electrical conductivity decreased with increasing NaF for low temperatures but increased at higher temperatures. The activation energy showed an increase with increasing NaF. The data suggest that the conductivity is not due to the total fluorine ion concentration.     

Managing the Knowledge‐Creating Context: A Strategic Time Approach

Understanding the contexts of knowledge is necessary to manage knowledge processes successfully. The goal of this paper is to provide a theoretical framework for understanding and utilizing knowledge that is embedded in contexts, focusing on the relationship between time and knowledge processes. This paper integrates the time lens and the literature on the knowledge based view to develop four different time contexts that can enable different organizational knowledge processes. Propositions on how to utilize time to create enabling contexts for organizational knowledge creation and innovation are developed. Suggested intervention strategies help to create contexts for knowledge creation and exploitation.     

开放式大坝安全监控系统总体设计

大坝安全监控系统是一个庞大的系统工程。基于大坝安全监控涉及信息量大、覆盖的知识面广等特点 ,遵循现代计算机应用软件模块化开发、可扩充、易操作的原则 ,充分利用网络技术、数据库技术、成熟的决策支持系统研制技术等学科先进理论及方法 ,提出了“一机四库系统”的设计思想 ,采用了三层Client/Server体系结构 ,设计了动态再生的系统平台 ,从而实现对大坝安全性态的实时在线监控 ,并且为通用的大坝安全监控系统的开发提供了一个新思路。     

分立拉曼放大器中的瞬态研究

研究了在有增益饱和的反向抽运光纤拉曼放大器 (FRA)中的瞬态现象 ,并通过解析表达式及数值分析发现瞬态持续时间可用信号在FRA光纤中的往返传播时间 (一般在 10 - 1 ms量级 )来表征。在级联FRA中功率瞬态会随着级数的增加而恶化。分析还表明在前向抽运的饱和FRA中 ,交叉增益饱和将导致信道串扰和消光比下降。最后讨论了如何设计增益箝制的FRA(GC FRA)以最大限度地抑制瞬态     

The Use of Ecological Momentary Assessment to Test Appraisal Theories of Emotion.

Although appraisal theories have received strong empirical support, there are methodological concerns about the research, including biased recall, heuristic responding, ethical issues, and weak and unrealistic induction of emotions in laboratories. To provide a more ecologically valid test of appraisal theories, the authors used ecological momentary assessment, in which the emotions and appraisals of Singaporean police officers were measured online over the course of an ordinary workday. The research focused on happiness. Support was obtained for predictions, demonstrating the generalizability of appraisal theories to a nonlaboratory setting and circumventing the shortcomings of previously used methodologies. Also, evidence was obtained that happiness was reported primarily in association with a specific combination of 3 relevant appraisals: high pleasantness, high perceived control, and low moral violation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

TOP3：事件

数字证书力促网银交易安全，短信网址号码首次统一，MP3联盟逃不过专利怪圈。[编者按]     

Equivalent nonlinearization of nonlinear systems to random excitations

The broadest class of solvable reduced Fokker-Planck equation is given and a new equivalent nonlinear method is presented to obtain an approximate probability density function for the response of a nonlinear oscillator to Gaussian white noise excitations. The method is based on the least mean-square criterion and Euler equation. It is shown that this method, which is simpler and more reasonable, generalizes Caughey's method and gives the same results as Cai and Lin under purely additive excitations. Examples are given to show the applications of the method. In one of the examples, this method leads to a better approximation than that obtained from the energy dissipation criterion.     

Online pricing for bandwidth provisioning in multi-class networks

We consider the problem of pricing for bandwidth provisioning over a single link, where users arrive according to a known stochastic traffic model. The network administrator controls the resource allocation by setting a price at every epoch, and each user’s response to the price is governed by a demand function. We formulate this problem as a partially observable Markov decision process (POMDP), and explore two novel pricing schemes––reactive pricing and spot pricing––and compare their performance to appropriately tuned flat pricing. We use a gradient-ascent approach in all the three pricing schemes. We provide methods for computing unbiased estimates of the gradient in an online (incremental) fashion. Our simulation results show that our novel schemes take advantage of the known underlying traffic model and significantly outperform the model-free pricing scheme of flat pricing.     

Sensor networks: evolution, opportunities, and challenges

Wireless microsensor networks have been identified as one of the most important technologies for the 21st century. This paper traces the history of research in sensor networks over the past three decades, including two important programs of the Defense Advanced Research Projects Agency (DARPA) spanning this period: the Distributed Sensor Networks (DSN) and the Sensor Information Technology (SensIT) programs. Technology trends that impact the development of sensor networks are reviewed, and new applications such as infrastructure security, habitat monitoring, and traffic control are presented. Technical challenges in sensor network development include network discovery, control and routing, collaborative signal and information processing, tasking and querying, and security. The paper concludes by presenting some recent research results in sensor network algorithms, including localized algorithms and directed diffusion, distributed tracking in wireless ad hoc networks, and distributed classification using local agents.