检索结果-南通市图书馆

A new coupled-map car-following model based on a transportation supernetwork framework

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第6期22卷 141-149页

作者：姚静黄婧祎陈关荣许维胜 department of Control Science and engineering Tongji University department of electronic and Computer engineering The Hong Kong University of Science and Technology department of electronic engineering City University of Hong Kong

A new car-following model is proposed by considering information from a number of preceding vehicles with intervehicle communication. A supernetwork architecture is first described, which has two layers： a traffic network and a communication network. The two networks interact with and depend on each other. The error dynamic system around the steady state of the model is theoretically analyzed and some nonjam criteria are derived. A simple control signal is added to the model to analyze the criteria of suppressing traffic jams. The corresponding numerical simulations confirm the correctness of the theoretical analysis. Compared with previous studies concerning coupled map models, the controlled model proposed in this paper is more reasonable and also more effective in the sense that it takes into account the formation of traffic congestion.

关键词： traffic flow coupled map car-following model inter-vehicle communication supernetwork

One-Step interpolation Predictive Vector Quantization of LSP Parameters

在线全文

学校读者我要写书评

暂无评论

The Journal of china Universities of Posts and Telecommunications 1996年第1期3卷 21-26页

作者： Bao Changchun(department of Telecommunication engineering, Changchun Posts and Telecommunications institUte,Changchun 130012,P.R.china)Dai Yisong(department of electronic engineering,Jinn University of Technology,Changchun 130022,P.R.china) department of Telecommunication engineering Changchun Posts and Telecommunications Institute Changchun 130012 P. R.China rinceton.edu

A new spectral coding approach,one-step interpolation predictive vectorquantimtion of the LineSPectrum Pair(LSP)coding,is proposed. With the use of the sufficient correlation of successive LSP vectorsand because of relatively slow variation of the short term spectrum of the speech waveform, the idea ofpredictive vector quantization and DPCM techniques are used to reduce variance Of the parameters to be quantics.18 bit/home split vector quantization scheme is designed to quantize the prediction *** average spectral distortion of 1.178 dB can be achieved when frame period is 30ms.

关键词： s:speech processing line spectrum Pair vector quantization

Design and analysis on a Gires-Tournois resonator based interleaver

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2009年第1期5卷 51-53页

作者：王秀琳黄文财张宇蔡志平 department of Physics Jimei University department of Physics Xiamen University department of electronic engineering Xiamen University

A flat-top interleaver,in which a mirror on one arm of the Michelson interferomefer is replaced by a G-T resonator,is *** the interleaver,the parameters including the channel spacing of 50 GHz,ripple less than 0.05 dB,-0.5 dB passband of 43 GHz(86% of the spacing),-30 dB stopband of 42 GHz(84% of the spacing),and a channel isolation higher than 40 dB,are achieved.

关键词： Design and analysis on a Gires-Tournois resonator based interleaver THz

An ultrathin wide-band planar metamaterial absorber based on a fractal frequency selective surface and resistive film

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第6期22卷 570-575页

作者：范跃农程用志聂彦王鲜龚荣洲 School of Optical and electronic Information Huazhong University of Science and Technology department of Mechanical and electronic engineering Jingdezhen Ceramic Institute

We propose an ultrathin wide-band metamaterial absorber （MA） based on a Minkowski （MIK） fractal frequency selective surface and resistive film. This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film. The finite element method is used to simulate and analyze the absorption of the MA. Compared with the MA-backed copper film, the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz-20 GHz. The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA. Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled. Finally, further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA. This absorber may be used in many military fields.

关键词： wide-band metamaterial absorber fractal frequency selective surface resistive films

Study of a Modified Fast Adaptive Algorithm for Digital Beamforming

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and electronics 1998年第4期9卷 75-80页

作者： Wang Zhong(Dept. of electronic Tech., Chengdu Climate College, 610054, P. R. china)Huang Shunji(department of electronic engineering, University of electronic Science and Technology of china,Cbengdu 610054, P. R. china) Dept. of electronic Tech. Chengdu Climate College 610054. P. R. China department of electronic engineering University of Electronic Science and Technology of China Chengdu 610054 P. R. China

This paper provides a modified fast adaptive algorithm for digital beamforming. It is analgorithm with strict constraint minimum power sampling matrix gradient (CSMG). It has merits ofboth traditional sampling mains gradient (SMG) and strictly constrained minimum power adaptivealgorithm. 16-element uniform circular array is selected. Some results of computer simulation aregiven. The results indicate that the beam direction will change with constraint angle and can beadaptable to adjust zero very well. The algorithm is fast convergent.

关键词： Beam steering Adaptive algorithm Gradient Convergeuce

A Very Efficient Approach for the Synthesis of 2-D Recursive Fan Filters

在线全文

学校读者我要写书评

暂无评论

The Journal of china Universities of Posts and Telecommunications 1995年第1期2卷 25-34页

作者： Zhu Weiping(department of Telecommunication engineering, Nanjing University of Posts and Telecommunications Nanjing 210003, P. R. china) AND Shogo Nakamura (department of electronic engineering, Tokyo Denki University Tokyo 101, Japan)

In this paper, we present a very efficient approath for the synthesis of twodimensional (2-D) re-cursive fan filters based on 1-D filter design. The investigation of the elliptical approximation theory mekesit possible to decompose a 1-D analogue filter into a series-parallel combination of all-pass sections. The 1-Ddigital filter obtained from this decomposition, while used as the prototype for 2-D filter synthesis, results ina grearly simplified realization architecture for fan filters. The final transfer function of the fan filter,which is reduced lo a combination of several lower-order all-pass sections, not only has fewer coefficients butalso enjoys optimal magnitude response. Some illustrative examples are given in this paper to show the effec-tiveness and simplicity of the proposed method.

关键词： digital filters filter algorithm recursive filtering methods

The Design, Performance Analysis and Implementation of VCAT in Backbone Networks for Software Radio System

在线全文

学校读者我要写书评

暂无评论

china Communications 2009年第1期6卷 85-91页

作者： Wang Peng1, JiaDong1, Jin Depeng2 , Zeng Lieguang2 1JiangNan Institute of Computer Technology, Wuxi, Jiangsu, 214083, P. R. china 2department of electronic engineering, Tsinghua University, Beijing, 100084, P.R. china JiangNan Institute of Computer Technology Wuxi Jiangsu 214083 China department of electronic engineering Tsinghua University Beijing 100084 China

Software Radio is a kind of promising technology in today and future’s communication systems. To share the resources of software radio systems to a large extent, we need to connect the instruments through backbone networks, such as the Multi-Service Transport Platform (MSTP), which is a dominating network technology that adopts both telecom and datacom traffic into existing transport infrastructures — Synchronous Digital Hierarchy (SDH). Virtual concatenation (VCAT) is one of the key technologies in MSTP. Compared with traditional contiguous concatenation, VCAT reduces transmission granularities, provides more flexibility to Network Management System (NMS) and as a result, improves the network efficiency greatly. In this paper, we introduce our design and implementation of VCAT module for a MSTP ASIC. The procedure of theoretical analysis to determine several important performance related parameters is also discussed in detail. The over- all design has been thoroughly simulated and verified through our self-made FPGA board, and has been successfully applied in our MSTP ASICs. We believe our work is significant for future development of software radio technology.

关键词： SRT VCAT NMS MSTP ASIC

Improved Populating Code-Excited Linear Predictive Coder

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Journal of china Universities of Posts and Telecommunications 1994年第1期1卷 45-51页

作者： Bao Changchun Zhao Guoqian (department of Telecommunication engineering, Changchun Post and Telecommunication institute, Changchun 130012, P. R. china) Dai Yisong (department of electronic engineering,Jilin University of Technology, Changchun 130012, P.

Although CELP coding has provided good quality synthetic speech at medium and low bit rates,the computation of an exhaustive search for stochastic codebook is extremely complex. This paper studies the exhaustive search procedure for determining the optimum excitation,and develops an effective search method by using improved populating codebook as excitation source. The computational cost of CELP coder was reduced to 1/26 that of a conventional full-gaussian codebook search.

关键词： Speech processing Vocoder Linear prediction

IN SITU INTERFEROMETRIC STUDY ON THE GELATION PROCESS OF POLYACRYLIC ACID GELS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2000年第4期18卷 373-377页

作者： Ying Guan Qiang Chen Xian-min Zhang Yu-xing Peng Jian Xu Polymer Physics Laboratory, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, china department of Information & electronic engineering, Zhejiang University, Hangzhou 310027, china Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, china Chinese Acad Sci Inst Chem Ctr Mol Sci Polymer Phys Lab Beijing 100080 Peoples R China Zhejiang Univ Dept Informat & Elect Engn Hangzhou 310027 Peoples R China Chinese Acad Sci Chengdu Inst Organ Chem Chengdu 610041 Peoples R China

In situ interferometry was used to investigate the gelation process of polyacrylic acid (PAA) gels. The basic principle of the in situ interferometry technique is illustrated. It can give sufficient information for non-destructive and successful investigation of the whole gelation process. The effect of initiator concentration on the gelation process was studied. The polymerization rate of AA increases with increasing initiator concentration. The error arising from the thermal effect in the gelation process can be neglected.

关键词： in situ interferometry gelation polyacrylic acid