A new texture image retrieval way

This paper proposes a new texture image retrieval method for the considering of the population search and random information exchange merits of evolving programming which can be used to optimize image feature vector extraction. The experimental results show that this way can efficiently improve the retrieval accuracy and realize fasttips with the advantage of evolving programming algorithm.     

Low-complexity blind multiuser detection of DS-CDMA signal in dispersive channels

The problem of blind multiuser detection in dispersive channels of Code-Division Multiple-Access (CDMA) in the presence of both Multiple-Access Interference (MAI) and In-terSymbol Interference (ISI) is considered. In practice, it is showed that by incorporating the desired user's signature waveform and the auxiliary vector, the information of the user can be identified using the suboptimal subspace method. The major contribution of this paper is to propose a minimum-mean-square-error detector with the suboptimal subspace-based blind technique for joint suppression of MAI and ISI in the dispersive CDMA channels.     

混沌反馈调制语音保密通信系统

在硬件实验研究的基础上,建立一种环形蔡氏电路,简述其工作原理及其特点。在此基础上提出用环形蔡氏电路实现混沌反馈调制的一种语音保密通信方案,分析了该方案的同步原理,讨论了发送端和接收端电路参数匹配情况下的同步收敛特性,设计了硬件实验电路,进行了语音混沌保密通信的硬件实验研究,给出了实验结果。     

激光干涉诊断电热化学发射装置产生的等离子体射流

叙述了用光楔错位干涉与高速摄影技术相结合诊断电热化学发射装置中等离子体发生器产生的等离子体射流的方法,得到了等离子体射流的电子密度和温度等参数的分布。该方法有助于改进电热化学发射装置中等离子体发生器的设计及其效能的提高。     

Schottky barrier thin-film transistor (SBTFT) with silicidedsource/drain and field-induced drain extension

A novel Schottky barrier thin-film transistor (SBTFT) with silicided source/drain and field-induced drain (FID) extension is proposed and demonstrated. In the new device configuration, a metal field-plate (or sub-gate) lying on the passivation oxide is employed to induce a sheet of carriers in a channel offset region located between the silicided drain and the active channel region underneath the main gate. The new device thus allows ambipolar device operation by simply switching the polarity of the bias applied to the field plate. In contrast to the conventional SBTFT that suffers from high GIDL (gate-induced drain leakage)-like off-state leakage current, the new SBTFT with FID is essentially free from the GIDL-like leakage current. In addition, unlike the conventional SBTFT that suffers from low on-off current ratio, the new device exhibits high on/off current ratio up to 10⁶ for both n- and p-channel modes of operation. Moreover, the implantless feature and the ambipolar capability of the new device also result in extra low mask count for CMOS process integration. These excellent device characteristics, coupled with its simple processing, make the new device very promising for future large-area electronic applications     

Beam-cavity interaction circuit at W-band

In this paper, we describe the design, fabrication, and bench study of a millimeter-wave cavity employed as a relativistic klystron output structure. The oxygen-free electronic-grade copper cavity was prepared by electro-discharge machining and diffusion bonding, and cleaned and tuned to 91.4 GHz. Measured cavity characteristics are presented and compared with theory, including quality factor Q, coupling parameter β, scattering matrix S₁₁, and axial electric field profile E_z. This paper provides the basis for an understanding of the cavity as a transfer structure     

Reconfigurable parallel inner product processor architectures

This paper presents a novel approach for low-power high-performance inner product processor design. The processor is dynamically reconfigurable for computing inner products of input arrays with four or more combinations of array dimensions and precision. The processor mainly consists of an array of 8×8 or 4×4 small multipliers plus two or three arrays of adders. It requires very simple reconfigurable components. The whole network may be reconfigured by using a few control bits for the desired computations, and the reconfiguration can be done dynamically. The design is regular, modular, and can easily be pipelined, and most parts of the network are symmetric and repeatable. A set of low-power high-performance parallel counters is also proposed for the implementation of the design, which could lead to a significant reduction in worst case power dissipation compared with traditional binary-logic based architectures, while showing superiority in speed, VLSI area, and layout simplicity     

Via-free broadband microstrip to CPW transition

A broadband microstrip to coplanar waveguide (CPW) transition is proposed. The design is based on vertical resonant coupling between the microstrip and CPW. The transition does not require via holes, wire bonds, or air bridges. The design of the transitions at C band shows good agreement with return loss better than -15 dB over 2.8-7.5 GHz. The new transition has the advantages of broad bandwidth and easy fabrication     

Admission control in time-slotted multihop mobile networks

The emergence of nomadic applications have generated a lot of interest in next-generation wireless network infrastructures which provide differentiated service classes. So it is important to study how the quality of service (QoS), such as packet loss and bandwidth, should be guaranteed. To accomplish this, we develop am admission control scheme which can guarantee bandwidth for real-time applications in multihop mobile networks. In our scheme, a host need not discover and maintain any information of the network resources status on the routes to another host until a connection request is generated for the communication between the two hosts, unless the former host is offering its services as an intermediate forwarding station to maintain connectivity between two other hosts. This bandwidth guarantee feature is important for a mobile network to interconnect wired networks with QoS support. Our connection admission control scheme can also work in a stand-alone mobile ad hoc network for real-time applications. This control scheme contains end-to-end bandwidth calculation and bandwidth allocation. Under such a scheme, the source is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real time applications. In the case of ATM interconnection, the bandwidth information can be used to carry out an intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine via simulation the system performance in various QoS traffic flows and mobility environments     

DWDM系统维护与故障处理初探

随着波分复用技术在传输网络上的进一步应用,对波分复用系统的维护和故障处理成了广大维护人员关心的重点,本文主要以实际的例子探讨了维护和排障工作的方法和要点,为日常工作提供参考。