最新刊期
卷 29 ， 期 2 ， 2001
- 摘要：The charging characteristics of the MOSFET memory based on Si nanocrystals with various channel dimensions are investigated in the temperature range of 20-300K.Large threshold voltage shifts up to 1.8V are obtained,being obviously dependent on the channel width,and independent of the channel length.It is experimentally found that the threshold voltage shift and charge retention characteristics are almost independent of temperature.Single electron/hole charge/discharge processes are observed in the device with the narrowest channel.关键词：silicon nanocrystal;memory;MOSFET4|1379|2更新时间：2025-07-16
- 摘要：A high-efficiency clustering algorithm is presented for solving standard-cell style placement problem with very large number of cells.Compared to traditional clustering algorithms,the main feature of the presented algorithm is that an information library including all interconnect relationships between cells is built and well organized before placement,thereby endowing the clustering algorithm with characteristics of global optimality and non-redundancy computation.The clustering algorithm has been applied to a quadratic placement procedure.Experimental results show that our clustering algorithm is very perfect in both clustering quality and clustering speed,thus solves the placement problem with very large number of cells successfully.关键词：standard cell;clustering;quadratic programming;placement2|947|1更新时间：2025-07-16
- 摘要：An implementation of a low-power motion estimator dedicated to MPEG2 MP@ML is proposed.It adopts an improved multi-resolution telescopic search algorithm with low complexity.For the coarse search procedure,a new two-stage method,in which motion track search is conducted followed by adaptive telescopic search,is used instead of the unitary conventional telescopic search.In addition,the two-stage search can be early ended in accordance with the motion situation.Simulation results show that,compared with the conventional algorithm,the new algorithm reduces the computational load to only 30% while maintains same quality of the decoded pictures.To accelerate the two procedures of coarse search and motion vector refinement,a systolic array and an array of improved tree architecture are devised.Techniques such as clock gating and operand isolation are used to reduce the power consumption of the motion estimator.关键词：motion estimation;low power;multi-resolution telescopic search;clock gating2|809|0更新时间：2025-07-16
- 摘要：Monte Carlo analysis of inversion layer mobility in 6H-SiC metal oxide semiconductors is presented under the size quantization.The simulation results fit experimental data very well.A new comprehensive model for Coulomb scattering in inversion layers is developed in this paper.The model takes into account the effect of the fixed charge in insulator,the interface-state charge,the charge of the ionized impurities and their correlation.Interface roughness scattering is shown to play a strong role in the high effective transverse field.On the low effective transverse field side,Coulomb scattering becomes important.关键词：6H-SiC;monte carlo study;scattering;coulomb charge2|1360|1更新时间：2025-07-16
- 摘要：The influence of structure on hot-carrier-effect immunity for deep-sub-micron n-channel metal-oxide-semiconductor field-effect transistors (NMOSFETs) is studied using two-dimensional device simulator Medici and compared to that of counterpart conventional planar devices.The simulated structure parameters include negative junction depth,concave corner and channel effective length.Simulation results prove that grooved-gate device can deeply suppress hot carrier effect even in deep-sub micron region.The simulations also indicate that hot-carrier effect is strongly influenced by concave corner and channel length for grooved gate MOSFET.In the end,the results obtained in this work are explained from the point of interior physical mechanism of device.关键词：grooved-gate NMOSFET;hot-carrier-effect;concave corner;negative junction depth2|791|1更新时间：2025-07-16
- 摘要：Principle and method for designing high voltage thin film SOI devices with linearly doped drift region are given.LDMOS transistors are fabricated on the SOI wafers with Si film of 0.15μm and buried oxide of 2μm.The dependence of breakdown voltages of the thin film SOI devices on the concentration gradient in the linearly doped drift region is experimentally investigated for the first time.Based on the optimization of the impurity dose in drift region,the breakdown voltage over 612V is observed in the SOI LDMOS transistors with 50μm drift region.关键词：thin film SOI;high-voltage;linear doping;LDMOS2|1932|3更新时间：2025-07-16
- 摘要：The advent of the Internet and the wide availability of computers,scanners and printers make digital data acquisition,exchange and transmission a simple task.However,making digital data accessible to others through networks also creates opportunities for malicious parties to make salable copies of copyrighted content without permission of the content owner.Digital watermarking is likely to be a potential solution to this problem.Digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia documents in networked environments.It makes possible to embed a watermark (such as identification data,serials number,text or image etc.) to multimedia documents allowing copyright protection,secret communication,document authentication and so on.In this paper,we present a new digital image watermarking method based on SVD (Singular Value Decomposition),and then give some theoretical analysis about the algorithm.Extensive experimental results show that this method is much more robust than other methods presented before.关键词：digital watermark;singular value decomposition;robustness2|3420|101更新时间：2025-07-16
- 摘要：The known key escrow scheme requires equal number in key recover escrow side.This paper proposes a new key escrow scheme.In recovering session key,any assigned number of escrow side is allowable.When increasing,reducing and changing the member of escrow side,it is not necessary to modify the storing key part,and no more than 4n+1 (n is positive integer) RSA operations are needed respectively for key split or key recover.关键词：key escrow;protocol;threshold scheme2|1058|2更新时间：2025-07-16
- 摘要：Global motion compensation coding is a novel coding method based on models.Its coding efficiency is higher than that of conventional coding method with motion compensation,so it is fit for very low bit-rate applications.But the key technology of global motion compensation coding is not solved well at present,such as global motion estimation,so global motion compensation coding has not been applied widely in real-time applications.This paper focuses some research on key problems of global motion compensation coding to solve real-time global motion compensation coding.The new fast method of global motion estimation is proposed and is used in global motion compensation coding,thus the speed of global motion compensation coding is accelerated.Comparative experimental results are shown in the paper.The speed of global motion compensation coding is improved compared with former method of global motion compensation coding.2|1056|3更新时间：2025-07-16
- 摘要：This paper disscusses the probabilistic model evolutionary algorithms which are a class of new algorithms proposed recently.After introducing the original and the principles of these classes of algorithms,the paper analyzes the complex computation caused by the complex models.Based on this,a new fast evolutionary algorithm based on probabilistic models is proposed.Also,a fast algorithm which uses the Bayes network model combined with the climbing-hill searching is realized.The experimental results show that the new algorithm has quick,reliable and accurate performance.关键词：evolutionary algorithms;probabilistic models;fast computing2|1140|5更新时间：2025-07-16
- 摘要：In this paper,one of the new problems encountered in the query optimization of ORDB(object relational data base),that is,how to optimize the expensive predicates contained in the query,is discussed.In traditional query optimizers,selections have been handled by "pushdown" rules under the assumption that selection can be processed with little time or no time,and selections are processed immediately after the scan of the relation,so as to diminish the size of relations to be joined.In ORDB,however,complex methods can be embedded in selections,thus selections may take significant amount of time,and the assumption for "pushdown" is no longer sound,so attention must be paid on this new problem.Based on the analysis of some solutions,a new algorithm Predicate_Rolling_Up is presented.关键词：query optimization;join algorithm;expensive predicate;ORDB2|862|0更新时间：2025-07-16
- 摘要：This paper proposes statistical processor demand analysis(SPDA) scheme for stochastic soft real-time system.The scheme can be used to estimate the lower bound on the probability that a job meets its deadline under fixed-priority preemptive schedule.Numerical solution to SPDA is also presented.The simulation results of an example system have shown that SPDA has a high computing speed and an error below 6%.It can provide important reference for the design of soft real-time applications.关键词：stochastic soft real-time systems;SPDA analysis;lower bound estimation4|1029|0更新时间：2025-07-16
- 摘要：A simple fast algorithm by DHT to utilize various DWTs,based on structuring a transform between N-order DWTs and N-order DHT,is proposed here.The algorithm is simple in computational structure and the total number of operations for each transform is less than 5N.关键词：discrete Hartley transform;discrete W transform;fast algorithm2|1259|0更新时间：2025-07-16
- 摘要：A new method for indexing large amounts of points in high-dimensional space is proposed.The basic principle is as follows:uniformly partition the data space by Lattice vector quantization,store the lattice points by Inverted File,organize the inverted file by Trie tree,and fast access the inverted file by Trie parallel search algorithm.We called this index structure LIFT.Compared with the traditional index methods,the LIFT can build the index structure with low complexity,support very high dimensionality,and take advantage of sparsity of data points in high-dimensional space,etc.The experiments show that for high-dimensional data,the LIFT outperforms the well-known R-tree.关键词：index structure;similarity retrieval;vector quantization2|960|3更新时间：2025-07-16
- 摘要：A discriminative learning method of environmental features is proposed for robust speech recognition,in which a simple classifier and the gradient descent algorithm are firstly used to iteratively learn the environmental features,and then the pure speech features are estimated from the observed speech features.Finally the estimations of the pure speech features are used in the back-end HMM classifier.Using the proposed method,a 33.3% reduction in word error rate is obtained relative to conventional HMM system for a speaker-independent,small vocabulary recognition task.关键词：robust speech recognition;environmental features;discriminative learning2|942|2更新时间：2025-07-16
- 摘要：This paper presents a mothod for deciding non-product-form solution systems models using station balance by means of Stochastic Petri Net(SPN).We find out three kinds of Petri net structures which may cause staiton non-product-form solution.We also give a method of solving performance bounds for non-product-form solution systems.关键词：stochastic Petri nets;station balance;non-product-form solution;product-form solution;performance bounds2|1085|1更新时间：2025-07-16
- 摘要：The distributed database (DDB)architectures as well as their data query strategies,are quite different from traditional HLR-VLR structure.This paper presents a methodology for evaluating hierarchical DDB architectures,based upon users' pdf of mobility and call characteristics.The main interests to DDB's performance are cost and call delivery delay,and research shows they are much better than those in a HLR-VLR structure.关键词：mobility management;DDB;distributed data query strategy2|780|0更新时间：2025-07-16
- 摘要：The disk array can enhance the capacity and throughput of disk storage system,which can tolerate single disk failure and accurately reconstruct lost data.But the reconstruction may reduce the throughput in the reconstruction period because of the spending of increased disk access.An approximate image reconstruction algorithm at client is proposed according to the image compression properties,which divides image into a few subimages and stores them on different disks of disk array.The relativity of DCT blocks can be used to approximately reconstruct damaged images without increasing disk access.关键词：disk array;image compression;discrete cosine transform;image recovery;multimedia server2|882|2更新时间：2025-07-16
- 摘要：Incremental placement or ECO placement is a new field in VLSI layout to meet the demand of high performance design.It detects illegal cell positions and moves cells locally to find a feasible placement solution.This paper proposes an incremental placement algorithm for standard-cell design mode.It adopts row partitioning to cope with various placement constraints,and then inserts trouble cells one by one.An integer programming (IP) problem is constructed and solved to get the best solution of cell insertion.A dual diagonal searching (DDS) method is proposed to solve this special IP problem.We prove that DDS can always be the best solution and its time complexity is O(n).Experiments on a group of industrial test cases show that our algorithm is efficient and robust.It runs 10 times faster than a simple heuristic method and reduces more than 20 percent placement modification in average.关键词：incremental placement;standard-cell;dual diagonal searching4|1167|1更新时间：2025-07-16
- 摘要：This paper describes a novel method to realize microprocessor compensated crystal oscillator (MCXO) by using the dual-mode excited AT-cut quartz crystal resonator (QXR).According to the harmonic effect,normalized beat frequency of the 3rd overtone frequency and 3 times of the fundamental frequency is almost linearly dependent on the changes of ambient temperature.By stimulating the fundamental and the 3rd overtone frequencies output simultaneously,the changes of ambient temperature was measured by the beat frequency and the temperature compensation was accomplished by the utilization of the dependence of the temperature on the beat frequency and the method of pulses deletion.This temperature measurement technique can eliminate the thermal lag due to the difference in thermal time constants of the QXR and the thermistor,and can overcome the limitation of temperature field gradient.The implementation of the means in MCXO is described.The dual-mode oscillating circuit and its block diagram are given and the practical experimental data are discussed.2|1478|0更新时间：2025-07-16
- 摘要：The symmetrical and asymmetrical double probes have been used to diagnose the electron temperature and the electron energy distribution in the dielectric barrier discharge,respectively.In this paper,the principle and setup of the diagnosis are described briefly,and the experimental results are discussed.It can be proven from these results that its electron temperature can be increased by decreasing the filled pressure and can be higher than that in DC discharge,and its electron energy distribution is obviously deviated from Maxwellian.关键词：probe diagnosis;electron energy distribution;dielectric berrier discharge;silent dischange;Plasma diagnosis;plasma display2|864|3更新时间：2025-07-16
- 摘要：We present an on-wafer measurement technique of semiconductor wafer using special coplanar microwave probes.The probe parameters are repeatable enough for S-parameter measurements and the probe life is with 100,000 contacts guaranteed.The multi-contact microwave wafer probe has been developed for on-wafer testing and sifting of GaAs integrated circuits with coplanar type.The insertion loss of microwave probe with a GSG footprint pattern is typically less than 3.0dB,and the return loss is at least 10dB at frequencies below 14GHz.关键词：microwave probe;on-wafer test;semiconductor integrated circuit2|1623|1更新时间：2025-07-16
- 摘要：With the development of low power mobile wireless personal communication and the improvement of performance of CMOS technology,to implement a RF front end of a wireless communication system using CMOS technology is not only neceessary but also feasible.In this paper,special issues to implement the RF integrated circuits are discussed.Firstly,a variety of transceiver architectures are reviewed in comparison of their characteristics and kernel issues that should be addressed in transceiver design.Secondly,important building blocks of CMOS RF front end,including low noise amplifier,mixer,frequency synthesizer and power amplifier,are discussed.The core subject of such building blocks such as figure of merit,possible circuit schematics and others are presented.Thirdly,the possibilities and methods to integrate the inductor and capacitor in the RF band are figured out in this paper.And,finally a perspective for the development of CMOS RF integrated circuits are dressed out.关键词：CMOS radio-frequency integrated circuits;architecture of transceivers;low noise amplifier;mixer;frequency synthesizer;power amplifier2|2809|5更新时间：2025-07-16
- 摘要：The actuality and the developing level of lipreading at the present time is introduced in this paper,and the contents,approaches and the significance on the research of lipreading are paid particular attention to.This paper aims to arouse people's attention and interests into this new field,to participate in the study of the lipreading problems actively,and to achieve more successes correlated to this problem.关键词：lipreading;lip movement;automatic speech recognition;gesture recognition;expression computing3|2540|13更新时间：2025-07-16
- 摘要：To resolve the contradiction of domain currency and abstract quality of automatic abstracting systems,we put forward the solution to build automatic abstracting systems based on multiagent technologies.To build such systems,there are two key problems:firstly,how many abstracting agents for each domain are suitable in some load.Secondly,what coordination strategy should be used.In this paper,the model of an automatic abstracting system based on multiagent technologies is given,and three kinds of coordination algorithms are set forth.We analyze the performance of the system based on the simulations,and get suitable number of abstracting agents for each domain in given load.Furthermore,we compare three given coordination algorithms.关键词：automatic abstracting;multiagent system;agent number;coordination algorithm;simulation;analysis2|848|3更新时间：2025-07-16
- 摘要：Collective I/O is a kind of effective organization of I/O subsystem.In the paper we analyze the data sieving technique and present the design and implementation of a parallel I/O system.The performance evaluations have shown good I/O performance.关键词：Collective I/O;data sieving;NOW2|1083|0更新时间：2025-07-16
- 摘要：We first introduce the bandwidth-delay-constrained least-cost multicast routing problem,and then propose a related heuristic genetic algorithm.The algorithm has the following characteristics:(1)the preprocessing mechanism,(2)the tree structure coding method,(3)the heuristic crossover technique,and (4)the instructional mutation process.Finally,simulations are showed to prove that the genetic algorithm is efficient and effective.关键词：QoS;multicast routing;NP-complete problem;genetic algorithm2|1490|11更新时间：2025-07-16
- 摘要：Routing approach influences the switch rate and load equilibrium of network directly.In China mainland,network switch rate is about 45%.It is said that raising one percent of switch rate of current telecommunications network will result in revenue almost one billion Yuan RMB.In the paper,on the bases of demerit-analysis of route-selecting methods being used in switch,a new routing approach based on neural network prediction was presented,including performance indicators,routing method,and recurrent neural network prediction.After that,simulation results were analyzed and compared.It's better by virtue of its better distribution and intelligent decision ability,and provides excellent solution to improve network switch rate and balance network load.关键词：routing;neural network prediction;switch rate;load balancing2|850|2更新时间：2025-07-16
- 摘要：The development of Internet applications necessitates routers' ability to support those functions such as firewalls,provision of QoS or traffic billing etc.All these functions need classification of packets,based on which it is determined how different packets are processed subsequently.In this article,the authors survey the recent advances in the research of IP classification and introduce some of the typical algorithms.The authors also evaluate three of them in a virtual environment and compare their pros and cons.关键词：IP classification;lookup algorithm2|1373|4更新时间：2025-07-16
- 摘要：In real-time applications,such as IP phones and remote conference systems,packet loss that impairs quality of transmitting severely is inevitable.FEC (Forward Error Correction) is a better way for repairing lost packets.In this paper,a method of lost repairing with FEC based on RTP(Real-time Transport Protocol) was designed and implemented. Then a testing method of lost repairing function and results are illustrated.关键词：FEC;packet loss;lost repairing;RTP3|1824|4更新时间：2025-07-16
- 摘要：The requirements for software configuration management (SCM) technologies in component-based software development are studied,and the component-based SCM system model has been proposed,which can satisfy the requirements.In this paper,an SCM system based on this model is introduced,and the management strategies and key techniques of the system are discussed.关键词：software engineering;software configuration management;software reuse;software component;version control2|1508|10更新时间：2025-07-16
- 摘要：A key management scheme for multilevel security in distributed applications is presented.The scheme adopts BELL-LaPadula model as multilevel access control policies.We use Chinese Remainder Theorem,introduce the notions of first-secret-key-element,second-secret-key-element and writing-element,and construct sharing information of session key.The scheme is efficient,secure and dynamic.At the same time,there are many practical applications involving the scheme for key management such as meeting in the network and talking in the network etc.关键词：key management;multilevel security system;Chinese remainder theorem;distributed application3|1211|3更新时间：2025-07-16
- 摘要：The Max-Log-MAP algorithm (MLM) is a simplified version for the decoding of Turbo codes.Architecture of parallel array is suggested based on the MLM algorithm and is easy to implement by VLSI.The data flow directions and the computation procedures of the algorithm structure are obtained,the relations among the nodes and data frames are analyzed and the simple time sequencing of data operations are given.The architecture is justified by computer simulation.关键词：Max-Log-MAP algorithm;soft output decoding;parallel structure;array2|900|0更新时间：2025-07-16
- 摘要：A novel software-only video codec is presented in this paper.By using modified block truncation coding and motion compensation technique based on one-step predictive motion estimation,the proposed codec can compress real-time videophone pictures below the bit-rate of 100 kbps on current PC.Compared to other similar algorithms,the presentation has substantially improved performance in bit-rate and PSNR at the premise of keeping the real-time property.关键词：software-only video;block truncation coding;motion compensation;decimation/interpolation2|1771|1更新时间：2025-07-16
- 摘要：This paper describes a dependability analysis algorithm for degradable fieldbus system.Our algorithm is valid for a general problem model:The system contains several performances (each performance consists of several particular functions),and can be at different performance at the beginning of work.In addition,the system's performance will be changed by some faults as it is working.Finally,the structure of system is scalability.In this paper,reliability and availability are connected to evaluate the dependability of system.Another difference between our algorithm with previous algorithms is that our algorithm is based on system performances.关键词：fieldbus;degradable system;dependability2|1162|1更新时间：2025-07-16
- 摘要：We give an optimal dynamic model with ASE amplified spontaneous emission noise power consideration for wavelength converters using semiconductor optical amplifiers (SOA) via cross-gain modulation (XGM).The theoretical results indicate that bigger bias current can perform better ER and SNR.Pump power should be in a certain range to get good performance.There is an optimal length of SOA for certain pump and probe wave.The experimental results of wavelength conversion of 2.5Gbit/s SDH signal can be explained by this model.关键词：cross-gain modulation;all optical wavelength conversion;ASE;semiconductor optical amplifier2|1284|1更新时间：2025-07-16
- 摘要：The SiGe/Si HBTs operating at low temperature were fabricated.The current gain hfe(Ic/Ib)over 16000 and β(ΔIc/ΔIb)over 26000 have been observed at 77K,exceeding those at 290K by about 51 and 73 times,respectively.The temperature dependence of DC characteristics of the HBT between 290K and 77K was described and analyzed.The departure from theoretical expectation of this dependence at very low temperature was discussed.2|928|1更新时间：2025-07-16
- 摘要：In order to accommodate to the irregular fabrication configuration,the 3D electromagnetic parameters extraction method of partial element equivalent circuit (PEEC) technology is used to model the cells of automatically partitioned ground/feeding plane with arbitrary shape.Then the response analysis in the time domain for the nonlinear circuit including I/O buffers is performed.The simulation result for a high-speed dual-coplanar PCB well fits the measured one,which indicates the validity of the proposed method.关键词：dual-coplanar PCB;PEEC technology;automatically partition4|945|0更新时间：2025-07-16
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