指针推进移动性管理策略中指针链长度的概率

为了降低移动通信网络中位置跟踪操作的代价,指针推进策略被提出.显然,指针链长度的确定对这一策略的有效应用是至为重要的.已有论文假定移动台在位置区的逗留时间服从指数分布的条件下,对指针链的长度进行研究,但指数分布的特殊性,限制了其研究结果的应用.本文推广了上述结果,研究了移动台在位置区的逗留时间服从一般概率分布的指针推进策略,通过构造向量马氏过程,利用密度演化方法,导出了指针链长度的概率公式,这个公式可用于对各种指针推进策略性能的评价.     

固井声幅-变密度测井的影响因素分析

利用声幅－变密度测井进行固井质量的评价受到诸多因素的影响，各种影响因素对声幅－变密度测井资料的影响作用有较大的差异，根据大量测井资料分析和实验研究，对仪器偏心、测井时间，套管尺寸与重量，地层岩性，气侵、水泥环微间隔等因素的影响作用进行了较为深入的分析，为各种影响因素的识别与校正提出了相应的方法和依据。     

On the interior resonance problem when applying a hybrid FEM/MoMapproach to model printed circuit boards

A hybrid finite element method/method of moments (FEM/MoM) technique is used to analyze a printed circuit board power bus structure where the source and observation points are in the near field. The FEM is used to model the lossy region between the planes of the board including the source. The MoM is used to model the region outside the planes and provide a radiation boundary condition to terminate the FEM mesh. Numerical results for a bridged power bus structure are compared with measurements. A nonphysical interior resonance of the electric field integral equation is observed. The problem can be avoided by using a hybrid technique based on a combined field integral equation     

An iterative ADI-FDTD with reduced splitting error

We present a new iterative alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method. By recognizing the ADI-FDTD method as a special case of a more general iterative approach to solve the Crank-Nicolson (CN) FDTD scheme, the splitting error in ADI-FDTD can be reduced systematically. Numerical examples are used to illustrate the improved accuracy of this method.     

美国、加拿大城市规划与建设考察报告

为扩大我省工程咨询业在国外的影响,进一步加强工程咨询企业的国际合作,学习和借鉴发达国家在城市规划与建设领域的先进理念和经验,受美国、加拿大相关部门的的邀请,经省发展改革委批准,由江苏省工程咨询协会组织的业内领导及工程咨询专业技术骨干赴美国、加拿大考察团一行9人,于6月15日至27日对美国、加拿大城市规划与建设情况进行了学习考察.     

Effects of contact shape on biological wet adhesion

Wet adhesion is widely adopted in biological adhesion systems in nature. Wet adhesion is studied in this paper with the focus on the effect of different contact shapes (flat, concave, convex, and ring-like) on the adhesion force. The evolution of the liquid bridge between a fiber tip and substrate during the detaching process shows two transition points. The first transition from the radius-controlled to the contact-angle controlled process is critical to influence the strength and robustness of adhesion. We show that a concave shape is more effective than a flat one, while a convex shape has no advantage. A ring-like contact shape has advantages in a hydrophobic environment and on a rough surface.     

软件无线电中采样率转换技术的实现及在3G中的应用

目前移动通信标准繁多,且新旧体制混杂,很难做到统一.为了实现互连互通,目前比较可行的方法是采用软件无线电.采样率转换技术是实现互连互通的关键.文中针对第三代移动通信系统(3G)中不同通信体制的带宽、速率要求,根据分级变换的思想,对3G中的CDMA2000和TDSCDMA的采样率转换方案进行了设计,并对3G中的5种制式的采样率转换方案进行了分析比较.实验表明,这一方案可以在采样率变换的高效网络结构基础上进一步降低滤波运算量和存储量.     

基于随机分析和概率预测的固定式海洋平台结构风险评估研究

对极端海况进行了环境荷载的联合概率分析。引入了整体不确定性和敏感性分析理论,利用非正态过程、具有不同相关性的多变量随机模拟技术,求解结构的失效概率。提出结构失效分析的新方法,并利用DNV提供的历史数据,对结构失效的后果做了适当分析。以埕北12-C井组平台为实例,对平台甲板高程(Air Gap)失效分析进行了实例计算。结果表明,使用多维联合极值分布理论及相应的求解方法,是离岸工程结构物风险评估的重要手段。     

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.