Optimal and self‐tuning fusion Kalman filters for discrete‐time stochastic singular systems

Based on the optimal fusion estimation algorithm weighted by scalars in the linear minimum variance sense, a distributed optimal fusion Kalman filter weighted by scalars is presented for discrete‐time stochastic singular systems with multiple sensors and correlated noises. A cross‐covariance matrix of filtering errors between any two sensors is derived. When the noise statistical information is unknown, a distributed identification approach is presented based on correlation functions and the weighted average method. Further, a distributed self‐tuning fusion filter is given, which includes two stage fusions where the first‐stage fusion is used to identify the noise covariance and the second‐stage fusion is used to obtain the fusion state filter. A simulation verifies the effectiveness of the proposed algorithm. Copyright © 2008 John Wiley & Sons, Ltd.     

A framework to integrate software behavior into dynamic probabilistic risk assessment

Software plays an increasingly important role in modern safety-critical systems. Although, research has been done to integrate software into the classical probabilistic risk assessment (PRA) framework, current PRA practice overwhelmingly neglects the contribution of software to system risk. Dynamic probabilistic risk assessment (DPRA) is considered to be the next generation of PRA techniques. DPRA is a set of methods and techniques in which simulation models that represent the behavior of the elements of a system are exercised in order to identify risks and vulnerabilities of the system. The fact remains, however, that modeling software for use in the DPRA framework is also quite complex and very little has been done to address the question directly and comprehensively. This paper develops a methodology to integrate software contributions in the DPRA environment. The framework includes a software representation, and an approach to incorporate the software representation into the DPRA environment SimPRA. The software representation is based on multi-level objects and the paper also proposes a framework to simulate the multi-level objects in the simulation-based DPRA environment. This is a new methodology to address the state explosion problem in the DPRA environment. This study is the first systematic effort to integrate software risk contributions into DPRA environments.     

Synthesis, Characterization and Crystal Structure of Quaternary Complex of Gadolinium （Ⅲ）

Ａｎｕｍｂｅｒｏｆｌａｎｔｈａｎｉｄｅｔｅｒｎａｒｙｃｏｍｐｌｅｘｅｓｃｏｎ ｔａｉｎｉｎｇｈｅｔｅｒｏｃｙｃｌｉｃａｍｉｎｅｓｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄｓｉｎｃｅ1960 [1] .Ｉｎｒｅｃｅｎｔｙｅａｒｓｍｕｃｈａｔｔｅｎｔｉｏｎｈａｓｂｅｅｎｐａｉｄｔｏｑｕａｔｅｒｎａｒｙｃｏｍｐｌｅｘｅｓｏｆｌａｎｔｈａｎｉｄｅｓｂｅｃａｕｓｅｏｆｉｎ ｔｅｒｅｓｔｉｎｇｓｔｒｕｃｔｕｒｅ ,ｃｏｏｒｄｉｎａｔｉｏｎｍｏｄｅ ,ｃｏｍｐｅｔｉｔｉｏｎｒｅ ａｃｔｉｏｎａｎｄｐｒｏｐｅｒｔｙ[2～ 9] .ＥＳＲｃａｎｅ…     

A distributed adverse drug reaction detection system using intelligent agents with a fuzzy recognition‐primed decision model

Discovering unknown adverse drug reactions (ADRs) in postmarketing surveillance as early as possible is highly desirable. Nevertheless, current postmarketing surveillance methods largely rely on spontaneous reports that suffer from serious underreporting, latency, and inconsistent reporting. Thus these methods are not ideal for rapidly identifying rare ADRs. The multiagent systems paradigm is an emerging and effective approach to tackling distributed problems, especially when data sources and knowledge are geographically located in different places and coordination and collaboration are necessary for decision making. In this article, we propose an active, multiagent framework for early detection of ADRs by utilizing electronic patient data distributed across many different sources and locations. In this framework, intelligent agents assist a team of experts based on the well‐known human decision‐making model called Recognition‐Primed Decision (RPD). We generalize the RPD model to a fuzzy RPD model and utilize fuzzy logic technology to not only represent, interpret, and compute imprecise and subjective cues that are commonly encountered in the ADR problem but also to retrieve prior experiences by evaluating the extent of matching between the current situation and a past experience. We describe our preliminary multiagent system design and illustrate its potential benefits for assisting expert teams in early detection of previously unknown ADRs. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 827–845, 2007.     

基于嵌入式Linux的远程数据采集系统

以嵌入式微控制器为核心,将传感器网络收集来的数据通过无线电发射机发送到远程接收机,从而实现远程数据采集.系统的优势是充分利用了短波无线链路资源,适合于工作在无人区等场合.以ARM7为控制器,功耗小,性能稳定,维护方便;通信方式采用串口通信,连接线少,实现相对简单.系统设计主要应用嵌入式μCLinux系统设计、无线电发射、调制解调器等方面的知识,文中给出了调制解调器拨号协议、系统原理和软件流程等.     

Experimental Research on Erbium-doped Superfluorescent Fiber Source

The effects of the variations in fiber length, fiber mirror reflectance on efficiency and output power are experimentally investigated for erbium-doped double pass backward superfluorescent fiber sources (SFSs). The influence of fiber length on mean wavelength stability (MWS) has also been demonstrated. By incorporating a short section of un-pumped erbium-doped fiber (EDF) at the output port, the pump power dependent on MWS becomes independent of pumped EDF length. This is a novel phenomenon that hasn‘t been reported up to now,and should be helpful to SFS fabrication and theory analysis. By using a fiber Michelson interferometer as spectrum slicing component,a multi-wavelength fiber source (MWFS) with ～20 channels (from 1542nm to 1559nm) is got. The MWFS has a channel spacing of ～0. 8 nm which satisfies ITUstandard. The intensity fluctuation among channels is less than 0.5dB,and the extinction ratio of all channels is above 14dB. This kind of MWFS should be useful to wavelength division multiplexing systems.     

宏蜂窝模型的传播模型校正研究

详细介绍了 宏蜂窝传播模 型校正的基本操作流程 结果分析及注意事项 对工程 ,人员了解和开展模型校正工作有一定的指导作用 。     

国内3G网络共享问题之研究

随着国内3G时代的来临，3G网络共享问题越来越受到人们的关注。本文结合国内移动通信的现状，着重分析了3G网络共享的模式及经济效益，论述了3G网络共享的相应策略。     

Analysis and comparison of two-dimensional permanent-magnet arrays for planar motor

This paper investigates three kinds of permanent-magnet arrays used in planar motors with polarity centers distributed in the lattices of a matrix. The magnetic field of every kind of magnet array is analyzed by analytical methods. First, we give a Laplace equation of magnetic scalar potential and a series of boundary conditions. Then, we derive the analytical expressions of magnet field strength and magnet flux density in the air gap of each kind of magnet array by the method of separation of variables. Finally, we compare the three types of magnet arrays on the basis of the analytical solutions.