含介质的边界振动的微腔中薛定谔猫态的产生

采用全量子理论，考虑了边界振动的含克尔介质的微腔（振动边界视为频率为 的量子谐振子）与单模辐射场构成的系统，给出了系统的时间演化算符及其变换，得到了系统的态函数随时间的演化关系.讨论了当振动边界回到初态时的腔场态，得到了许多与已有文献不同的薛定谔猫态，这对于研究猫态的性质和应用是十分有意义的.     

增强数据速率业务(EDGE)

介绍了基于TDMA (时分多址 )的第 2代移动通信系统向第 3代系统的过渡技术EDGE (增强数据速率业务 ) ,分析了它对现有网络的影响及其提供的数据业务 ,并指出了它在技术上的优点 ,说明EDGE是一种很好的向第 3代网络演进的方式。     

基于多粒度软件网络模型的软件系统演化分析

软件系统是一类典型的人工参与的复杂系统,理解软件系统的演化规律有助于更好地指导软件工程实践.本文从包、类和特征三个粒度上构建软件系统的网络模型,利用复杂网络理论依次从网络规模、质量、结构控制三方面定量分析软件系统演化规律.以经典的Lehman演化定律为基准,对比软件系统在不同粒度下的演化差异.研究结果表明：（1）不同粒度下软件系统表现出的演化特性有所不同,其中在类粒度下效果更好;（2）持续增长、持续变化、自我调节和主体维持四项定律表现出与构建软件网络的粒度无关;（3）包粒度下系统演化对软件质量影响不大,而反馈系统定律仅在类粒度下成立.     

适应NGN/3G演进的我国数字集群通信务实发展策略

文章阐述我国数字集群通信现状及主要问题,指出数字集群通信的重要性及其与 N GN /3G 演进的关系,重点论述适应 NG N /3G 演进要求的我国数字集群务实发展的策略。     

Current role and future evolution of the ISDN Signaling system inNTT's network

The current role of the integrated services digital network (ISDN) Signaling System is examined, covering general features of the ISDN protocol, functionalities supporting ISDN services, and functionalities supporting existing services. The Signaling System No.7 (SS7) network and its operation are described. The future evolution of the ISDN signaling system is discussed     

反射式需求工程过程演化建模

用反射机制为软件系统需求工程过程演化建模,将需求工程过程的开发活动作为反射系统的基层,实现软件系统的功能需求,将软件系统的非功能需求作为反射系统的元层,对需求工程过程的开发活动进行调节、控制,并将非功能需求的性质反射到功能需求.定义了有色Petri网及其范畴,并用有色Petri网范畴描述软件系统非功能需求性质的模拟、保持和反射机制;用有色Petri网建立反射式需求工程过程演化形式化模型,模拟了软件系统需求工程过程中功能需求和非功能需求的迭代、增量、演化,为软件系统需求工程过程演化建模提出了一种新的方法.     

Sequential Detection of Markov Targets With Trajectory Estimation

The problem of detection and possible estimation of a signal generated by a dynamic system when a variable number of noisy measurements can be taken is here considered. Assuming a Markov evolution of the system (in particular, the pair signal–observation forms a hidden Markov model (HMM)), a sequential procedure is proposed, wherein the detection part is a sequential probability ratio test (SPRT) and the estimation part relies upon a maximum a posteriori probability (MAP) criterion, gated by the detection stage (the parameter to be estimated is the trajectory of the state evolution of the system itself). A thorough analysis of the asymptotic behavior of the test in this new scenario is given, and sufficient conditions for its asymptotic optimality are stated, i.e., for almost sure minimization of the stopping time and for (first-order) minimization of any moment of its distribution. An application to radar surveillance problems is also examined.      

Explanation of launch condition choice for GRIN multimode fiberattenuation and bandwidth measurements

In order to predict the attenuation and bandwidth of a graded index (GRIN) multimode fiber system accurately, the fiber composing the system is best characterized by a restricted launch attenuation measurement and an over-filled-launch (OFL) bandwidth measurement of the fibers. The rationale for these launches is provided in terms of the power evolution in the fiber and its impact on system performance, and the basic physics of GRIN multimode fiber. Experimental results are shown that demonstrate the results     

量子计算与超导量子计算机

量子计算是一种基于量子力学相干叠加原理的新型计算体系,具有超越传统计算体系的优越性能。超导量子计算因为其在规模可扩展性方面的潜力而得到广泛的重视。超导约瑟夫森结是超导量子计算机方案中的关键器件,可用来控制超导体中的宏观波函数。阐述了量子计算的发展和优势,介绍了约瑟夫森结的原理以及三种超导量子比特的特性,并分析了面临的挑战。     

ISDN applications at Tenneco Gas

The evolution from analog to integrated services digital network (ISDN) telecommunication services at Tenneco Gas and the features of its telephone system are described. The results of implementing ISDN in data operations are examined. The benefits of ISDN for Tenneco are briefly summarized     

面向LTE-Advanced的CoMP试验系统及外场试验网

介绍了面向下一代移动通信系统的发展与演进,分析了3GPP LTE-Advanced系统需求指标及关键技术,针对LTE-Advanced系统协作多点(CoMP)技术,研发了试验系统,并基于试验系统搭建了外场试验网。测试结果表明了CoMP技术的优势。     

System performance evaluation of the FSA submarine opticalamplifier system

The FSA submarine optical amplifier system developed for commercial use is designed to transmit 2.5 and 10 Gb/s signals flexibly; its repeater spacing is 90 km. It contains six line pairs to yield a maximum transmission capacity of 60 Gb/s. Its system configuration, and the characteristics of its fibers and optical amplifiers, which realize effective dispersion and optical passband management, are introduced. We discuss its performance with regard to the parameters significant in optically amplified transmission: evolution of zero dispersion wavelength (ZDW), polarization mode dispersion (PMD), and fiber nonlinearity induced impairments. Signal-to-noise ratios (SNR's) for 2.5 and 10 Gb/s signal transmission are measured and the improvements offered by polarization scrambling are also discussed. Finally, ZDW, PMD, and SNR characteristics of the system after installation are reported     

Operations and management of a campus packet network

The operation and management of the Kansas University Packet Switch Network (KUPSN),which provides interactive and file transfer services to its users, is discussed, focussing on the problems encountered and solutions developed. Areas of network management of particular concern are identified, and tools developed to deal with them are described. Management system integration and the evolution of problem-handling procedures are discussed     

COSNET-a coherent optical subscriber network

A complete coherent multichannel system, designed for application in the local loop, is presented. The concept of a uni- and bidirectional system and its technical realization in a laboratory demonstrator are described. The network control, including frequency management of the bidirectional channels, and network security are discussed. Attention is paid to the scenario for evolution from a narrowband to a complete broadband system. All aspects are integrated in a demonstrator, which is capable of supporting a large number of narrowband and broadband distributive and communicative services. Novel technical solutions for frequency management, data induced polarization switching (DIPS), high-speed encryption, and network signaling are presented     

TD-SCDMA移动通信系统的增强和演进

时分-同步码分多址(TD-SCDMA)作为具有中国自主知识产权的第三代移动通信标准之一,即将全面商用化。TD-SCDMA未来的增强和演进是目前热点问题之一,各种方案不断提出,但还没有一个结合短期发展和长期发展的可持续发展计划。根据采用的关键核心技术不同,文章提出了TD-SCDMA增强和演进的4阶段论:第一阶段为当前的TD-SCDMA阶段;第二阶段是TD-SCDMA短期演进,即HSxPA阶段(包括HSDPA、HSUPA和HSPA演进);第三阶段是长期演进阶段;最后一阶段是基于TD-SCDMA的时分双工(TDD)超3G(B3G)或者第4代移动通信系统阶段。详细描述了演进过程中每个阶段的主要特点,以及多输入多输出(MIMO)、正交频分复用(OFDM)等新技术在演进过程的使用。     

3GPP LTE小区间干扰协调方案研究

随着3G移动通信系统逐步成熟,3GPP已经开始了对其长期演进(LTE)系统的研究和标准化工作。由于使用了新的物理层技术,使得小区间干扰抑制成为一个热点问题。针对该问题,介绍了目前小区间干扰协调/躲避研究方面的现状,对几种具有代表性的方案进行了研究,最后对各方案进行了系统级计算机仿真分析。     

Gibbs光学双稳系统稳态与非稳态运转区域的确定

从Gibbs混合光学双稳系统的耦合方程出发，利用线性稳定性分析的方法，确定了系统稳态与非稳态的运转区域。并数值分析了系统在非稳态区域的动力学行为，即系统失稳后的演化模式。结果表明，当延迟时间取不同数值时，非稳态区域的状态可以是稳定、周期振荡和混沌。     

The statistics of polarization-dependent loss in opticalcommunication systems

In this letter, we study the statistics of polarization-dependent loss (PDL) in optical systems and evaluate its evolution with system length. We show rigorously that within the range of conceivable parameters in optical links, the distribution of PDL is Maxwellian when it is expressed in decibels. The accumulation of the mean-square PDL with system length stays linear in most systems, but may assume an exponential growth in very long systems with large PDL. The analytical results are compared with numerical simulations and an excellent agreement is observed     

Experimental identification of thermal induced warpage in polymer–metal composite films

Composite thick films consisting of multi-layered polymers and metals are widely used in integrated circuits(IC) and its packaging, and it arises intricate stress and warpage problems due to complex inner stress distribution and evolution. The wafer warpage origination and evolution of multi-layered polyimide (PI)/Cu composite film is measured in-situ by a Multi-beam Laser Optical Sensor (MOS) system. It's found that PI has an intricate influence on wafer warpage evolution and Cu plastic deformation due to viscoelasticity and glass-transition, and the influence differs in different structures and at different temperatures. Nonlinearity of the curvature–temperature curve of the composite occurs at much lower temperature than in single PI or Cu film, showing mutual effect of PI and Cu. Unlike bare or capping PI film that totally stress relaxed at high temperature, bottom PI coated by Cu film sustains a medium compressive stress, indicating that Cu coating film has restrained stress relaxation of PI. The warpage evolution during heating is different from that during cooling, perhaps due to different deformation mechanism.     

Engineering education in Poland

Basic engineering education in Poland is described. The factors effecting education which are specific to that country, including its political situation and the efforts of the academic community during the last several decades to keep in touch with the global flow of people and information, are emphasized. The basic structure of the Polish educational system is discussed and illustrated with several statistics. The decentralization of the academic system is discussed, along with obstacles to further progress. The evolution of curricula for students of telecommunications is analyzed, and the aid of the European Community (EC) in restructuring and modernizing Polish universities is presented. Some comments on continuing education are made