最新刊期
卷 ， 期 10 ， 1995
- 摘要：Medical ultrasonic imaging technique has been widely used clinically. Unfortunately,the resolution of ultrasonic imaging is much lower than that of X-CT. In order to improve the resolution of ultrasonic imaging, efforts have have made in the field of tissue characterization in past decades. The objective of ultrasonic tissue characterization is to extract characteristic acoustic parameters from the ultrasonic echoes quantitatively,to reconstruct the medical imaging with these parameters,and then to improve the resolution of ultrasonic imaging and the effectiveness of diagnosis. In this article, the basic methods used in the area of ultrasonic tissue characterization is discussed and the progresses on integrated backscatter and elastogram are introduced. Some potential problems for further research are also discussed.关键词：Ultrasound;Tissue characterization;Integrated backscatter;Elastogram3|137|4更新时间：2025-12-08
- 摘要：Trace functions have been widely used in error correcting coding for many years,but only a few years ago the significance of trace functions in the design of stream ciphers had been recognized.For reasons, trace functions suddenly become well-known and more and more important in stream designs. Based on this situation, the paper reviews the developments and achievements in stream designs. Suggestions and view points of the author are presented too.关键词：Trace functions;Sequences;linear complexity;correlation2|132|8更新时间：2025-12-08
- 摘要：The mobile communication channel suffers from severe fading distortion due to multipath phenonmenon. This makes it necessary to adopt anti-multipath techniques in high speed mobile communication systems. On the basis of an overview of typical mobile communication channels, this paper presents survey on anti-multipath techniques in TDMA and CDMA mobile communications systems,with special attention paid to adaptive channel equalization,RAKE receiver and multiuser detection.The recently proposed diversity technique using adaptive array is also addressed.关键词：mobile communications;Multipath fading channel;Adaptive equalizer;RAKE receiver;multiuser detection;Adaptive antenna2|789|14更新时间：2025-12-08
- 摘要：In this paper some research developments and application results of the theory of waves and fields in inhomogeneous media have been summarized. Particularly some efficient numerical methods used in both forward analysis and inverse calculations of electromagnetic fields in inhomogeneous media,and their applications in numerical modeling and imaging of electrical logging have been introduced.关键词：Inhomogeneous media;Electrical logging;numerical modeling;Electromagnetic scattering and inversion2|470|20更新时间：2025-12-08
- 摘要：Based on our research achievements in the field of intelligent control in recent years and combined with some noticeable international trends,the progress on intelligent control theory is briefly surveyed.关键词：intelligent control;Intelligent analogue;Aritificial intelligence;Complex systems2|459|16更新时间：2025-12-08
- 摘要：Multicast Backbone is one of the key technologies for constructing high-speed broadbandnetworks. Many multimedia applications such as video conference systems or ccoperative office automation systems have been developed based on MBone. However, Multicast Commnunication of multimedia data on MBone brings about overload of the network,so that new algorithms and mechanisms are needed to control and manage the QoS （Quality of Service）of networks. This paper summarises the state of the art on MBone and QoS management.关键词：成组广域广播;多媒体应用;服务品质3|69|4更新时间：2025-12-08
- 摘要：A survey of current international research on MEMS is presented. The principal technology involved in MEMS and its industrial application are introduced. We have also analyzed MEMS related research conducted by leading international institutes and some suggestions are proposed for future development of MEMS technology in China.关键词：MEMS;Micromachines;sensors;Actuators2|399|48更新时间：2025-12-08
- 摘要：Companied with the rising of "Information Super Highway",Distributed Multimedia as an interdiscipline field is being paid much more attention. How to think about it and how to forsee its development tendency are very important for researchers and developers in this field. From the perspective of computer science,this paper tries to expound its rising,communciation platforrm,communciation protocol,distributed multimedia database and its applications.关键词：multimedia;Distributed multimedia;Multimedia database;Computer supported cooperative work（CSCW）.2|104|5更新时间：2025-12-08
- 摘要：Object-oriented programming has become a widely accepted and used important programming paradigm that is supported in many different languages. In this paper,an overview of current research on object-oriented programming languages （OOPLs）is given. The discussions focus on issues such as: semantics, type system, language features, distribution, OOPL variant and Smalltalk and so on.关键词：Object-oriented programming language;Type system;distribution;Prototypebased language;Smalltalk2|235|4更新时间：2025-12-08
- 摘要：Virtual reality（VR） is a new technology that tries to realize an intuitive and natural human-computer interaction. It will play an extremely improtant role in promoting computer applications.In this article,we first explain the concept and characteristics of VR,and then analyze its development situations,unsolved problems and key techniques for researches. After surveying the application potentials of VR,we propose a strategy for the development of VR researches and applications in China.关键词：virtual reality;Virtual environment;human-computer interaction;Telepresence;Application systems;Development strategy2|608|59更新时间：2025-12-08
- 摘要：This paper summarizes the state of computational electromagnetics. A classification of the traditional numerical metheds in electromagnetics is given. The emphasis is placed on the survey of newly developed numerical methods in electromagnetics which may become popular in the near future. Several suggestions have been made on the future research in this area.关键词：Computational electromagnetics;Splitting method;wavelet analysis;Surface radiation condition2|1519|51更新时间：2025-12-08
- 摘要：A survey of computer-aided filter design is given. The calculation of the transfer function （transducer function）is considered first,and the references with the source programs are listed.In computer-aided LC filter design,the bottleneck is pointed out,and the explicit formulae for all pole filter design are given. For active filter CAD,the rules of program development are discussed. A review of IIR and FIR digital filters is presented and the design of quadrature mirror filter banks is examined.关键词：filter design;CAD;Passive filter;active filter;digital filter;Filter approximation2|439|18更新时间：2025-12-08
- 摘要：This paper reviews the propagation studies on personal communication with emphasis on microcell and indoor environment. Some results of experiments and theoretical researches including the works by Tsinghua University are introduced,which could be references for microcellular designers.It is shown that the emerging personal communications have put their urgent requirements on more accurate propagation characteristics in PCS environment.关键词：PCS;Propagation models;Ray tracing approach;Path loss;Delay spread2|113|12更新时间：2025-12-08
- 摘要：The problems related to the testing and fault detecting of analog integrated circuits are reviewed. The specification oriented testing technique is introduced first. Then the fault model of analog intergated circuit and the fault oriented testing method are discussed. After the introduction of testability and the design for testability of analog integrated circurt,a new algorithm for the testing and fault detecting of analog integrated circuit based on the monitoring of power supply current is discussed in detail.关键词：Testing of integrated circuit;fault detection;Analog integrated circuit2|428|8更新时间：2025-12-08
- 摘要：Recently,there has been a growing research field on engineering and design for manUfacturability of integrated circuits. It is an integration of design,fabrication,assembly and test engineering group into the process of manufacturing an IC. Under the unitized framework of driven manufacturing cost and yield,IC product will be designed and programed. So,the technique can shorten the period of research and development,reduce the manufacturing cost,increase yield and reliability of IC products. This paper describes the research progress in IC manufacturability field and gives the direction tion of further study.关键词：integrated circuit;Engineering and design for manufacturability;Yield optimization2|131|11更新时间：2025-12-08
- 摘要：In this paper,the modelling simulation and performance evaluation techniques for information networks which are from the different angles including statistics level,logical level and time level are surveyed,the issues relating to the developing course and application states as well as the direction for futher research of these techniques are discussed. Some considerations about the implementation of the techniques due to the increasement of the difficulty and nonlinerity of the information networks are presented.关键词：Information networks;Queueing network theory;simulation;Perturbation analysis;Petrinet;Control theory;Discrete event dynamic system2|148|3更新时间：2025-12-08
- 摘要：Precision guidance technology is the kernel of precision guidance weapon. It is also a research focus of the weapon technologies in the present world as a mainstay technology in forming an informational battlefield. This paper tries to put forward an overview of the present situation and future development of precision guidance weapon and its relative technology through the discussion.关键词：Precision guidance technology;Terminal homing;Present technical situation;Developing trend2|337|11更新时间：2025-12-08
- 摘要：This paper discusses two topics in detail for engineering application of digital beamforming technology. （1）Digital Beamforming Feed: Digital beamforming feed is an effective way to reduce equipment. The paper presents the principle and deduces the formulae about weighting in feed for getting satisfactory patterns. （2）Test and Correction about the Amplitude and Phase Errors among Channels: A method to test errors by means of the patterns is given. It can either be used in phased array of cooperation feed,or space feed.关键词：Radar system;adaptive array;signal processing;pattern2|298|21更新时间：2025-12-08
- 摘要：The research issues that must be dealt with in the progress of automatic Chinese speech recognition from laboratory demonstration into commerical use were described briefly. The characteristics and rules of phonetic ceding for Chinese speech were examined,putting emphasis on:（1） More explicilty using language model at the initial/final level should be helpful for continuous Chinese speech recognition;（2）The combination of distinctive guiding features and descriptive uniform features should speed searching,reduce mismatching and improve discriminating allophones. The challenges for improving robust speech recognition at the acoustic processing stage was also discussed. A step by step training and adaptation method was presented for large vocabulary continuous Chinese speech recognition.关键词：speech recognition;language model;Acoustic processing;feature extraction;Training and adaptation2|482|50更新时间：2025-12-08
- 摘要：Digital image/video compression has been one of the hottest research areas in information technology in the past decade. In this paper,recent advances in image and video compression techniques are introduced. For still image compression,techniques based on human visual perception are emphasized, such as quantiser design in transform domain coding techniques. Techniques using neural network and fractal are introduced too. For video compression,the MPEG-2 technique is emphasized because of its benchmark position for video coding. The evolving MPEG-4 video coding（its general goal and requirement） is mentioned too. Model based coding is introduced as a potential method for MPEG-4. Finally, some current and future applications of digital image/video compresion techniques such as HIDTV are presented.关键词：Compression;Perceptual entropy;MPEG-2;MPEG-4;Model-based coding;Digital TV2|286|23更新时间：2025-12-08
- 摘要：In this paper,three traditional 3D imaging approaches called 3D imaging with beaded plate,projection-type 3D display and holograhpy are introduced first; then the metheds generating 3D stereoscopic imaging with computer are emphatically reviewed, including autostereoscopic display techniques which are intensitively dealed with by researchers in recent years;finally,the application of 3D stereoscopic imaging technique in aerospace, industry, education, medicine and national defense etc. are described and the main directions of 3D stereoscopic imaging technique in the future are predicted.关键词：D display;Autostereoscopic imaging technique;Man-machine interface2|1190|29更新时间：2025-12-08
- 摘要：The importance of Semiconductor Artificial Neural Networks（SANNs） is interpreted.The research contents and the main development in SANNs are discussed. The performance requirements of general purpose Neuro Processors are analyzed. By comparing the advantages and disadvantages of All Analog, All Digital and Digital-Analog processing mode,some basic ideas of research on general purpose Neuro Processors at present time in our country are proposed.关键词：Neural netowrk;semiconductor;Neuro processor;VLSI2|166|8更新时间：2025-12-08
- 摘要：The research fields,current level and problems of vacuum microelectronics are presented,including basic structures of vacuum microdevices, field emission array, physics of microtip,new materials,new principles of vacuum microelectronics and main applications.关键词：Vacuum microelectronics;field emission;New material;Field emission array;Field emission display;Microwave device2|129|9更新时间：2025-12-08
- 摘要：The potential advantages and the situation of thin-film fully depleted CMOS/SOI technology at home and abroad are discussed in this paper. The trend of developing CMOS/SOI technology is presented also. At last,the conclusion that the fully depleted CMOS/SOI will become the main technology in the next generation silicon VHSI and ULSI is obtained.关键词：CMOS/SOI;Fully depleted;SIMOX;BESOI2|159|12更新时间：2025-12-08
- 摘要：The research and progress of silicon heterojunction and pseudo-heterojunction bipolar devices are summarized on the basis of our previous work. It is indicated that GeSi HBT will be the dominant technique of silicon bipolar stuctures,and silicon pseudo-heterojunction bipolartransistor has the superiority for low temperature application.关键词：silicon;Heterojunction;Pseudo-heterojunction;Bipolar device2|54|0更新时间：2025-12-08
- 摘要：This paper elaborates the importance of modern frequency synthesizer techniques used in modern electronic system,and summarizes the trends of modern frequency sysnthesizer techniques to serialization, miniaturization, modularization and engineering practicability. The emphases are put on description of the latest progress of PLL frequency synthesizer and DDS which are used widely. Also, the advanced devices of monolithic PLL frequency synthesizer, ALL, monolithic DDS etc. and the advanced techniques of FLL, upconverter,miniaturization,etc. are introduced in detail.关键词：frequency synthesizer;Phase-lock;microwave;millimeter wave;Frequency agility2|717|129更新时间：2025-12-08
- 摘要：In this paper,the new technique of millimeter wave quasi-optical power combining and free spatial power combining are reviewed,and our own method and achievement are simply introduced.We also discuss the problems to be solved.关键词：millimeter wave;power combining2|624|50更新时间：2025-12-08
- 摘要：Spaceborne synthetic aperture radar（SAR） is a kind of modern high resolution sidelooking imaging radar. Making use of the techniques of the synthetic aperture,pulse compression and digital information processing,it obtains high resolution in azimuth direction and in range direction. In this paper,the present situation and development trend of spaceborne SAR are summarized. The main techniques of SAR are disscussed,which include spaceborns SAR patterns and systems,and information processing and imaging processing of SAR digital image. Finally, the imaging results using SEASAT-A satellite SAR raw data are provided.关键词：synthetic aperture radar;radar imaging;radar signal processing;Microwave remote sensing2|413|48更新时间：2025-12-08
- 摘要：The broad band microwave radiation generated in electron beam-phasma interaction has gotten more attention in recent years for its potential of tunable frequency. The main radiation mechanisms are plasma radiation and beam radiation. In this paper, the experimental investigations and the theroetical studies including the inverse Compton scattering,the bunched electron radiation due to Soliton field and the radiation by nonlinear plasma electron current are reviewed.关键词：Broad band microwave radiation;plasma radiation;Beam radiation2|130|2更新时间：2025-12-08
- 摘要：Designing and using low RCS radar antennas is an interesting and important research subject. In this paper,a review of antennas′RCSR is given and several RCSR techniques, such as offset reflector antenna,FSS main or sub-reflector antenna and FSS antenna or feed radome,offset feed, microstrip antenna,etc. are discussed. FSS sub-reflector antenna and FSS feed radome,which reduce the antennas′RCS by restraining the mode component of scattering by antennas,are more simple and can be easily used to practice. And a summary on the techniques and development of analyzing FSS is also given.关键词：antenna;Antenna scattering;microstrip antenna;radar cross section;frequency selective surface;Equivalent circuit model2|463|16更新时间：2025-12-08
- 摘要：Profile reconstructions of stratified medium are basic electromagnetic inverse problens.They are of great significance for reconstruction of complex medium. In this paper,the current situation of research on these problems is summaried,in which some of our works are included.关键词：inverse scattering;reconstruction;Stratified medium;Profile2|74|2更新时间：2025-12-08
- 摘要：This paper surveys generalized spectral domain immittance method,methtod of lines and its fast algorithm,full wave discrete image method and other full wave methods. The comparison of characteristics of these methods is also presented. They can be effectively used to analyse planar layer dielectric structures. The recent research works of authors are included in the paper.关键词：electromagnetic theory;Numerical analysis;Spectral domain method;Method of lines;Image theory;Planar layer dielectric2|132|4更新时间：2025-12-08
- 摘要：Investigations in the performance models and their computer simulations are important links in thermal imaging technologies and provide the theoretical basis and analytical tcols for system design,analysis,verification and genesis of new concepts. It is deemed as a key subJect of investigations in various countries and a number of model versions have been successively presented in USA. As our national thermal imaging technologies are developing ,investigations in this subject have advanced too. This paper reviews the state-of-art and progresses of the static performnace models of thermal imaging system at home and abroad,gives an analysis of the concepts adopted and the characteristics of technological proressing for several models,and points out the tendencies that deserve attention.关键词：Thermal imaging system;Infrared focal plane array;Static performance;Mathematics model;Computer simulations2|298|14更新时间：2025-12-08
- 摘要：Upon the strong motive force of society′s needs,the theory and technology on character recognition are developed. The theory system has been formed preliminary,the achievements in technology have begun to be practical in society. Although it is not ripe,the development of the research of brain and the improvement of the computer technology will promote its development until it reaches the goal.关键词：Charactet recognition;pattern matching;feature extraction;Combination of multiple classifiers2|1276|65更新时间：2025-12-08
- 摘要：Techniques in multisensor identity fusion for nilitary target identification are discussed in this paper. Included here are the definition,concept,processing construction and algorithm of identity fusion as well as examples of their application. The major problems and difficulties in identity fusion,possible ways ofsolution,and prediction of the future trend of the development in identity fusion techniques are also presented.关键词：data fusion;Estimate;target identification;Identity fusion;sensor2|614|65更新时间：2025-12-08
- 摘要：Research involving some sort of combination of Genetic Algorithms（GAs） and Artificial Neural Networks（ANNs） has attracted a lot of attention recently. Some current work combining GAs and ANNs can be divided into two broad categories:supportive combinations,which typically involve using a genetic algorithm to select training data and to interpret the output behavior of neural networks; collaborative combinatoins, which typically involve using the GA to determine the neural network weights or the network topology or both. This article presents a review of the state of the art and research prospects in this area.关键词：artificial neural networks;genetic algorithms;Evolution and learning6|2172|216更新时间：2025-12-08
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0