一种新的Shrinking序列周期及线性复杂度

给出了一种新的Shrinking序列模型,并且利用有限域理论,解决了这种新的Shrinking序列的周期及线性复杂度界。     

MIMO相关信道估计中训练序列的最优结构和最佳长度

针对存在空域相关性的多输入多输出（Multiple—Input Multiple—Output，MIMO）信道，首先设计了适用于任何给定长度的最优训练序列，该序列能够充分利用已知的信道相关信息，且具有估计均方误差最小化的特性．在此基础上，分析了相关信道下采用训练估计的数据传输机制所能达到的容量下界，得出了满足估计准确性和数据速率最优折中的最佳训练序列长度．最后，通过仿真验证了本文给出的训练序列的性能和最佳长度取值的有效性。     

邻区自配置优化简化TD-LTE网络运营

LTE网络标准化阶段由移动运营商主导提出自组织网络（Self—OrganizedNetwork,SON）的概念,目的是要通过自动化运营维护,将现在需要人员参与的工作变得自动化,尽量不需要大量人工来参与,尽量地节约运营维护成本。SON包括自配置（Self—Configuration）、自优化（Self—Optimization）、自诊断（Self—Healing）等方面。邻区自优化（AutomaticNeighbourRelation,ANR）属于自优化功能之一,能够自动维护邻区关系的完整性和有效性,从而减少非正常邻区切换,提高网络性能;另外还可以减少人工操作,降低运维成本。     

抽样序列的构造与分析

文章构造了一类新的抽样序列,给出了该序列的特征多项式、周期,并给出了de Bruijn序列控制下抽样序列的线性复杂度下界和1重量复杂度下界,分析了其在一个周期段内,该序列的0和1出现次数的相对差很小的、良好的伪随机性质。     

基于全状态伪随机序列的BIST设计

全状态伪随机序列发生器（ASPRG）是在FSR的基础上，通过修改其反馈函数而得到，其最大的优点就是利用了移位寄存器的全部状态，序列最大长度为2^n。本文首先推导得到4位和8位ASPRG的反馈网络函数，在此基础上应用ASPRG进行内建自测试（Build In Self Test）设计并优化电路结构，ASPRG既作为测试信号发生器，而它的另一种工作模式则作为特征分析使用。这样不仅简化了BIST设计，同时降低了功耗，具有较高的现实意义。     

序列的线性复杂度在循环码最小距离下界研究中的应用

本文首先介绍了有限域中傅氏变换及序列线性复杂度的概念,然后简述了循环码最小距离的几个下界,最后用序列的线性复杂度分析了循环码的最小距离,得到了关于最小距离下界的几个新定理。     

“停走”型钟控序列概率模型信息论分析

给出了"停走"型钟控序列概率模型的信息论分析,得到了控制序列与输出序列之间互信息熵的简单计算公式,给出了输入与输出序列之间互信息熵的一个下界.     

频率选择性信道下多节点放大转发协作通信中的信道估计方法

针对频率选择性信道下基于正交频分复用(OFDM,orthogonal frequency division multiplexing)技术的多节点放大转发(AF,amplify-and-forward)协作通信,提出了一种基于训练序列的最小二乘信道估计方法,推导出其均方误差性能的下界并给出了相应的最优训练序列方案.同时,该方法选取经功率分配优化后具有恒幅特性的Chu序列作为训练序列,实现了多节点AF协作通信中信道估计的最小均方误差.仿真结果证实了该信道估计方法在多节点AF协作通信环境下的有效性以及所提最优训练序列方案在系统性能上的优越性.     

GF（q）上新型自缩序列模型及研究

构造了GF（q）上一种新型的自缩序列模型,利用有限域理论,研究了生成序列的周期和线性复杂度,得到如下结论：周期上界q^n（q-1）/2,下界q^（q-1）（n/q）;线性复杂度上界q^n（q-1）/2,下界q^（q-1）[n/q]-1。这些结果表明生成序列是一种良好的密钥流序列。且当q=2时,恰是GF（2）上的自缩序列。     

序列的周期稳定性的新度量指标

本文提出了两种新的度量序列的周期稳定性的指标－定周期距离和变周期距离。文中还研究了一些序列的这两种指标的下界，并给出了衡量序列的周期稳定性的一种方法。     

胆小管超微细胞酶学研究

以电镜细胞化学的方法,观察了小鼠胆小管酶的分布。观察的12种酶中,NDPase和G6Pase三种酶分布于胆小管微绒毛;AlPase、Na~+-K~+ATPase、Mg~(++)-ATPase、Ca~(++)-ATPase、CMPase、ACase和5＇-Nase等7种酶分布于胆小管微绒毛,也分布于肝细胞邻接面细胞膜和Disse间隙微绒毛;ACPase、细胞色素氧化酶以及线粒体ATPase不分布胆小管微绒毛,也不分布Disse间隙微绒毛和肝细胞膜。据信,胆小管微绒毛上的酶参与胆汁成份的转运,提供转运所需能量以及还可能与某些代谢过程有关。本实验中磷酸水解酶类使用的铈基法及亚铁氰化钾半还原的锇酸后固定法,效果优于铅法。     

非对称性夹芯共型天线罩成型工艺设计

为满足雷达天线的圆筒状结构以及尺寸长、高空架设和力学强度要求高等特点,采用了以天线为成型模的共型罩结构和缠绕成型工艺,形成了天线与天线罩互为补强的一体性特点。为了解决天线罩对雷达天线的电性能影响,设计了非对称夹层结构,既加强了罩体强度,又因为蜂窝夹层的隔离作用,减少了罩体对天线电性能的影响,满足了雷达天线的性能要求。     

二硫化钼纳米薄片分散液的剥离制备

文中采用液相超声剥离粉末二硫化钼制备了纳米薄片分散液,通过紫外可见吸收光谱测定分散液的浓度,并探索了超声功率、超声时间以及二硫化钼初始浓度对纳米薄片分散液浓度的影响。实验结果表明,当超声功率为350 W,超声时间为48 h,二硫化钼初始浓度为10 mg/mL时,所制备的纳米薄片分散液浓度可达0.16 mg/mL。在剥离过程中加入聚乙烯吡咯烷酮,可以有效避免由于纳米薄片自身团聚而导致的分散液稳定性差的问题,所得到的二硫化钼纳米薄片分散液可稳定存放超过两个月;同时,PVP的加入可将二硫化钼纳米薄片分散液浓度提高至0.42 mg/mL。     

基于属性密码体制的区块链安全技术研究进展

区块链是一种集合了分布式存储、点对点传输、共识机制、密码学算法和智能合约等关键技术的分布式账本,具有去中心化、不可篡改、透明化等特性.近年来区块链技术的安全性问题逐渐显露,阻碍了区块链应用的发展.本文介绍了区块链的基本概念与安全模型,分析了区块链的安全性问题;然后,基于属性密码体制,从访问控制、密钥管理、数据隐私保护这三个方面分析了区块链安全技术的各类研究,论述了主要的解决方案的特点;最后,总结了基于属性密码体制的区块链安全技术研究进展,并对未来的研究工作进行了讨论.     

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.     

智能语音操控在广电端到端的系统设计及应用

在数字化中国的大背景下,在公司个人宽带与互动电视在线交费用户均突破300万户的情况下,为解决我们的用户总找不到自己喜欢看的节目,记不住频道名称和喜欢的节目,提升公司竞争力。通过对前端的点播系统、AAA系统、EPG系统、PORTAL系统、ISMP系统、媒资系统、机顶盒终端的功能进行剥离、整合和详细设计,最后完成终端用户语音操控电视直播、点播、时移、回看、页面操控、系统设置,并支持普通话和四川话方言的目的。达到提升用户体验,增加公司竞争力,促进业务的发展。系统试运行后,用户体验效果得到很大提升,完全达到预期设计目的。     

迈向数字经济新时代

数字经济以数字化丰富要素进行供给,以网络化提高要素配置效率,以智能化提升产出效能,推动经济发展质量变革、效率变革、动力变革,是保持经济中高速增长、高质量发展,建设现代化强国的关键驱动力量。首先阐述了把握数字经济发展新机遇的重要性,然后介绍了数字经济规模化高速增长和数字经济显著带动就业的现状,最后重点介绍了推进数字经济发展的关键点。下一步要加快工业互联网建设应用、推动企业数字化转型、完善政策环境、加强要素保障,从而进一步推进数字经济繁荣发展。     

铁路机车设备检修管理信息化系统的研究

随着国家轨道交通事业的迅速发展,铁路维修业务不断增多,铁路物资积累日趋丰富,鉴于自身发展的需求,文章提出在检修流程、任务派发、人员管理、物资使用、维修管理、物品存放、安全监测、循环利用等环节,都需要采用更加现代化的管理模式。通过对机车设备检修流程信息化的实现,进行检修产品全生命周期的管理,以及检修产品故障原因的总结和分析,提高检修管理和实施的效率,最终形成一个安全、稳定、高效、协同的精细化管理模式。     

Photo-Polymerization Induced Hierarchical Pattern via Self-Wrinkling

Hierarchical patterns are widely found on the biological skins in nature and can provide unique functions to surfaces such as wettability, optical, and adhesive properties. Herein, a facile and robust strategy to generate the self-wrinkling pattern on the surface of the photo-curing coating is proposed, which comprises a crosslinking monomer, photoinitiator, and fluorinated copolymer as additive. The fluorinated copolymer, which contains fluorocarbon chains possessing low surface-energy, tertiary amine as coinitiator, and anthracene in the side chain, can self-assemble to the top layer for constructing the gradient photo-crosslinking system. Upon the irradiation of ultraviolet (UV) light, the mismatch of shrinkage caused by the gradient photo-crosslinking leads to the formation of wrinkles, the morphology of which can be regulated by monomer proportion, the content of fluorinated copolymer, and the thickness of the film. Taking the spatiotemporal advantages of light, the hierarchical patterns of wrinkle are generated by programmed exposure with photomask, which has potential applications in anti-counterfeiting and encapsulation of light-emitting diode (LED) chip for displaying. This strategy provides a rapid and universal alternative method to fabricate a hierarchical pattern of the surface.     

基于ATMEL单片机及VB的船用调速器性能分析检测系统

详细介绍了利用Windows环境下实时分析软件和At89s52单片机组成的调速器性能分析检测系统。整个系统具有稳定可靠，测量精度高，实时性强，界面友好，操作简单的特点。主要功能实现根据由下位机传过来的转速值，动态分析柴油机转速变化，从而分析实时的调速阶段。最后计算出试验转速，最低转速，最高转速，稳定转速。动态调速率，瞬时调速率等技术指标。并可以保存所有数据资料，有很好的参考价值。