神经网络结构优化设计方法

神经网络的结构设计、优化方法是神经网络研究的一个方向,至今仍没一个系统有效的解决方法。主要列举了多种神经网络结构的设计方法,包括凑试方法、增长方法、修剪方法、进化方法、自适应方法和正交多项式误差逐次逼近法,并对这些神经网络优化设计的方法进行了评述和比较。     

基于调幅广播信号的动目标时差提取方法

分析了调幅信号的循环平稳性,并结合CCC方法得到了基于调幅信号的固定目标时差提取方法;进一步在分析CCC方法不足的基础上得到了运动目标时差提取方法AM-ECCC方法,仿真结果表明该方法不仅比相关方法性能有明显的提高,并且具有很好的抗噪性能。     

关键词自动标引方法综述

本文对关键词提取方法的研究进行了总结。对关键词自动标引方法进行分类梳理,将关键词自动标引方法分为统计分析方法、语言分析方法和人工智能方法三大类;主要介绍了近年比较常用的几种关键词自动标引方法,总结当前关键词自动标引方法存在的问题。     

基于改进FSM的协议一致性测试方法

介绍了一种基于FSM(finite state machine)的生成一致性测试序列的改进算法,该方法混合了UIO(unique input/output)方法和T方法,UIO方法的测试能力优于T方法,但是生成的测试序列的长度较后者要长一些。实验结果表明,本改进方法的能力与UIO方法相同,并且测试序列的长度接近于T方法。     

基于参数-值替换的错误定位方法

现有错误定位方法难以检测程序遗漏错误,提出一种方法层次的基于参数?值替换的错误定位方法。首先将出现在失败执行中的方法作为可疑方法候选集,计算该集合中元素对程序执行结果的影响度,再利用值替换技术计算高影响度方法的兴趣参数?值映射对,然后依据方法是否包含兴趣参数?值映射对对候选集中方法进行分类,并依据其影响度分别进行排序,最后生成一个可疑方法序列进行错误定位。实验结果表明该方法较其他错误定位方法具有更好的定位效果。     

面向数据融合的DS方法综述

DS方法作为一种重要的融合方法,已广泛应用于各种数据融合系统中.本文对基于DS方法的融合模型、DS方法的算法实现,以及DS方法的拓展等方面,进行了比较全面的论述.最后从数据融合角度对DS方法进行了简要的述评,并指出将DS方法与其它相关理论进行有机的结合是其主要发展趋势之一.     

电子电路中抗EMI设计

电磁干扰(EMI)可分为传导干扰和辐射干扰,消除干扰的方法可以采用硬件方法和软件方法,硬件方法主要有屏蔽、接地、隔离和滤波等,而软件方法主要是滤波。笔者对各种方法进行总结,并指出各种方法所存在的问题以及适用场合,并对一些常用方法提出改进措施。     

近红外星图质心检测C样条插值法和高斯方法比较

可见光CCD拍摄的星空图像中目标点的质心求取已经有了很多种方法,可见光中的恒星质心求取方法在近红外星图中同样适用,常用的方法有Gauss拟合法,矩方法（包括修正矩方法）和寻导法等。介绍了质心求取方法中的Gauss拟合法,分析其优劣性,并以这种方法为基础,根据近红外星图导航的实际情况提出了一种较为实用的方法,并验证比较其...     

一种改进的大规模网络拓扑发现方法

分析了基于ICMP协议的 Traceroute传统发现方法的低效,详细描述了双向树拓扑发现方法.结合启发式发现方法,提出了一种改进的拓扑发现方法.实验数据表明,该方法能够快速、准确地获得网络拓扑结构,更有效的降低网络负载.     

面向光束整形的自由曲面衍射光学设计方法(特邀)EI北大核心CSCD

光束整形技术能够实现激光光束能量分布的良好控制,在激光加工、医疗、激光核聚变等方面具有广泛的应用前景。光束整形方法主要分为几何光学方法和物理光学方法两大类,其中几何光学方法由于忽略了衍射效应,导致一些情形下的光束整形效果不够精细,但却能为物理光学方法提供良好的优化起点。结合几何光学方法和物理光学方法的复合设计方法能够设计出易于加工的自由曲面衍射光学元件,同时能抑制杂散光和散斑噪声。首先回顾了物理光学方法,然后综述了几何光学-物理光学复合设计方法的研究进展,最后对衍射光学元件设计方法的未来发展方向进行了一定的展望。     

Alternative Schemes for Dynamic Secure VPN Deployment in UMTS

Three alternative schemes for secure Virtual Private Network (VPN) deployment over the Universal Mobile Telecommunication System (UMTS) are proposed and analyzed. The proposed schemes enable a mobile node to voluntarily establish an IPsec-based secure channel to a private network. The alternative schemes differ in the location where the IPsec functionality is placed within the UMTS network architecture (mobile node, access network, and UMTS network border), depending on the employed security model, and whether data in transit are ever in clear-text, or available to be tapped by outsiders. The provided levels of privacy in the deployed VPN schemes, as well as the employed authentication models are examined. An analysis in terms of cost, complexity, and performance overhead that each method imposes to the underlying network architecture, as well as to the mobile devices is presented. The level of system reliability and scalability in granting security services is presented. The VPN management, usability, and trusted relations, as well as their behavior when a mobile user moves are analyzed. The use of special applications that require access to encapsulated data traffic is explored. Finally, an overall comparison of the proposed schemes from the security and operation point of view summarizes their relative performance. Christos Xenakis received his B.Sc. degree in computer science in 1993 and his M.Sc. degree in telecommunication and computer networks in 1996, both from the Department of Informatics and Telecommunications, University of Athens, Greece. In 2004 he received his Ph.D. from the University of Athens (Department of Informatics and Telecommunications). From 1998–2000 was with the Greek telecoms system development firm Teletel S.A., where was involved in the design and development of advanced telecommunications subsystems for ISDN, ATM, GSM, and GPRS. Since 1996 he has been a member of the Communication Networks Laboratory of the University of Athens. He has participated in numerous projects realized in the context of EU Programs (ACTS, ESPRIT, IST). His research interests are in the field of mobile/wireless networks, security and distributed network management. He is the author of over 15 papers in the above areas. Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Greece, in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981 and 1984, respectively. From 1983 to 1986, he was on the faculty of Electrical Engineering and Computer Science at the University of Connecticut, Storrs. From 1986 to 1994 he was on the faculty of the Electrical and Computer Engineering Department at Northeastern University, Boston, MA. During the period 1993–1994 he served as Director of the Communications and Digital Processing Research Center at Northeastern University. During the summers of 1990 and 1991, he was a Visiting Scientist at the IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens, Greece, where he is presently a Professor in the Department of Informatics and Telecommunications, and Director of the Communication Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. His research interests are in the design and performance analysis of broadband networks, and wireless/mobile communication systems and services. He has authored more than 150 papers in the above areas. Since 1995, he is leading the research activities of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies & Services (ACTS) and Information Society Technologies (IST) programmes funded by the European Union (projects RAINBOW, Magic WAND, WINE, MOBIVAS, POLOS, ANWIRE). He is chairman of the board of the Greek Universities Network, the Greek Schools Network, and member of the board of the Greek Research Network. In 1994, he received the Guanella Award for the Best Paper presented at the International Zurich Seminar on Mobile Communications.     

澳洲插头产品的法规要求及标准解析

介绍了澳大利亚插头产品的法规要求及插头的型式、尺寸、参数和测试要点,分析了插头的电流额定值和配线之间的关系,强调了插销绝缘套的要求。对重要的试验项目,如弯曲试验、插销绝缘套的耐磨试验、温升试验、高温压力试验进行了说明。     

卫星遥感温室气体的大气观测技术进展

全球、区域及城市的碳浓度、碳源汇信息是应对气候变化、达成双碳目标、完善国际谈判、支持治理政策制定与执行的重要依据。国际认可的“自上而下” 方法将卫星观测作为基础的通量计算技术, 是验证温室气体排放清单的重要手段。系统介绍了温室气体的卫星探测载荷原理、类别和发展, 以及反演、估算CO2、CH4 和N2O 的浓度和排放通量的方法, 还有探测缺失和误差存在的影响因素等; 分析了对卫星探测温室气体能力提高的迫切需求, 浓度反演和排放量估算精度不足, 以及N2O、氟化物等其他温室气体遥感研究缺乏、地基遥感验证能力薄弱等问题; 最后总结了我国温室气体卫星遥感技术的发展趋势, 主要是面向主被动高时空分辨率卫星的研制应用、高精度多尺度排放量估算(特别针对城市、小区域和点源尺度)、氟化物遥感评估等主题, 以加强对碳排放的量化观测, 并增强对碳循环的理解, 提高感知和应对气候变化的能力。     

Wireless IP and Its Challenges for the Heterogeneous Environment

The tremendous momentum toward building a mobile wireless Internet using the Internet Protocol (IP) has thrust many challenges upon the technology developers and the operators. These challenges encompass the 2.5G, 3G, and future solutions and standards. Some of the key issues deal with supporting IP traffic across different wireless and MAC protocols, end-to-end QoS and mobility, traffic engineering and scalability, protection/restoration, operations and management, authentication/privacy/security, billing, and content and context aware networking. This article addresses the drivers, the issues, and solutions (wherever possible) in the above areas, and concludes with a summarization of the challenges that lie ahead.     

单目图像序列光流三维重建技术研究综述

由单目图像序列光流重建物体或场景的三维运动与结构是计算机视觉、图像处理与模式识别等领域的重要研究内容,在机器人视觉、无人机导航、车辆辅助驾驶以及医学影像分析等方面具有重要的应用。本文首先从精度与鲁棒性等方面对单目图像序列光流计算及三维重建技术近年来取得的进展进行综述与分析。然后采用Middlebury测试图像序列对HS、LDOF、CLG-TV、SOF、AOFSCNN 和 Classic ＋NL 等典型光流算法以及 Adiv、RMROF、Sekkati 和DMDPOF等基于光流的间接与直接重建方法进行实验对比分析,指出各对比方法的优点与不足,归纳各类方法的性能特点与适用范围。最后对利用分数阶微分模型、非局部约束、立体视觉以及深度线索解决亮度突变、非刚性运动、运动遮挡与模糊情况下光流计算及重建模型的局限性与鲁棒性问题进行总结与展望。     

A Novel Local-Dielectric-Thickening Technique for Performance Improvements of Spiral Inductors on Si Substrates

A novel local-dielectric-thickening technique is presented for performance improvements of Si-based spiral inductors.This technique employs the processes of deposition,photolithography,and wet-etching,to locally thicken the oxide layer under the inductor,which can decrease the substrate loss and improve the inductor performance.Both the structures and processes are compact,economical,and compatible with CMOS processing.Several square spiral inductors with different inductances are fabricated,and the quality factors and the self-resonant frequencies both increase clearly with this proposed technique:for the 10,5，and 2nH inductors,the peak quality factors are effectively improved by 46.7%,49.7%，and 686%,respectively;however,the improvement percents of the selfresonant frequencies are more significant,which are 92.1%,91.0%,and no less than 68.1%，respectively.     

机动6m抛物面天线车结构总体方案探讨

文章遵循策划、分解、综合及优化的总体方案研究思路,根据要求,提出了三个机动6 m抛物面天线车结构总体备选方案;针对系统结构组成,详细分析了天馈线、天线座、拖车以及系统标定等子系统所有可能的结构方案;最后综合权衡研究三个备选方案在技术、质量、成本、周期等多方面的优劣,选择了最佳结构总体方案,确保了所选方案具有合理性、可行性、经济性、先进性和科学性。实践证明,所选方案用户满意,实施效果良好。     

攀枝花广电工程项目管理策略与方法运用

工程项目管理就是要求工程建设任务在规定的时间和成本控制范围内达到预期的各项管控目的,它贯穿于项目的设计、施工准备与施工、使用与维护3个阶段,重点是施工准备与施工阶段的安全、质量、成本、进度、合同方面的控制与管理。结合工作实践,介绍了攀枝花市广电工程建设项目在施工准备与施工过程中的管理策略及其方法运用。     

一种智慧协同网络多参数的多路径路由算法

多路径路由技术采用多条路径同时传输,作为优化资源配置和负载均衡的重要技术,在路由可靠性、QoS路由、传输效率等多方面比单路径传输具有优势.现有互联网网络资源配置和路由机制相对静态和僵化,导致多路径技术的发展存在发展的局限性.现有多路径技术考虑在路由层面不利于多路径路由选择和计算,难以保证传输性能,降低网络传输效率.智慧协同网络能够动态感知网络需求,灵活适配网络资源,更好的支持路由可扩展性.本文在智慧协同网络架构下提出了一种智慧协同网络多参数的多路径路由算法.该算法制定了智慧协同网络多参数的多路径路由协议,对网络性能参数CPU占用率、往返时延(RTT)、带宽进行加权计算得到路径权重值,根据权重值进行流量分配.采用图论理论对网络流量分配及模型进行了分析.并在Mini-Net平台上进行了开发和实验,结果表明,该算法能够优化网络配置,减小往返时延,提高网络吞吐量,从而提高网络性能,实现负载均衡.     

宇航用电感器和变压器的失效特征分析

基于美国宇航用电感器和变压器发生失效的类型、原因、检测方法和发生频次的数据，总结了其失效特征，并给出了电感器和变压器在MIL-STD-981中各项试验重要性的认识。通过对美国和国内宇航用电感器和变压器由设计、生产产生的失效和实验中失效的对比分析。给出了此类元件的失效特征。依据国情，提出了如何通过制定标准和失效数据分析工作来提高国产宇航用电感器和变压器可靠性的建议。