最新刊期
卷 28 ， 期 8 ， 2000
- 摘要：A digital watermarking technique based on multiresolution decomposition is proposed.By multiresolution decomposition technique,the decomposed watermarks of different resolution are embedded into the corresponding resolution of the decomposed original image,which makes the watermark be adapted to the original image.The algorithm can extract the watermark without the original image because the embedding procedure is based on the relationship between different resolution layers of the original image.Experimental results show that the proposed technique is robust to some image processing operations and Joint Photographic Experts Group (JPEG) lossy compression.关键词：copyright protection;digital watermark;discrete wavelet transform0|2|29更新时间：2025-07-02
- 摘要：In the paper,the value of RMS radius and the visual picture of escape electron dropped spots in optimum image plane has been given.The present paper has offered data to prove that when the βeta distribution changes from β1,8 to β21,the RMS radius value increases gradually,corresponding with theoretic analysis.It has offered data to check that the RMS radius not only can characterize the system resolution properties,but also does it correspond with the electron optical modulation transfer function (MTF) in image plane,and proved that expressing the system MTF by exponential function will have the properties of fast computation speed,succinct expression,convenient usage,and have enough accuracy in low frequency space.关键词：root mean square radius;modulation transfer function;imaging systems;βeta distribution;numerical computation0|2|3更新时间：2025-07-02
- 摘要：This paper deals with the design and optimization of tree-based power/ground network in the BBL VLSIs which is a new kind of layout patlern.This problem hasn't been well discussed so far.In this paper,a new algorithm is presented to solve this problem.The algorithm includes 3 steps:at first finding the channels between the modules,then routing the power trees according to several principles,and at last determining the branch width to get the minimal area.The algorithm has achieved the object which minimizes the area of power trees with high running speed.关键词：power;ground;BBL;Lagrange multiplier methods0|2|3更新时间：2025-07-02
- 摘要：In this paper,the fabrication of polarizable electrodes in electric double-layer capacitors (EDLCs) based on carbon nanotubes is studied.These talets are prepared by using molded mixtures comprising electrodes.EDLCs with specific capacitance of about 15~25F/g are obtained.Through surveying the major electric performance parameters for the obtained capacitors and comparing them with the ones for conventional activated carbon electrodes,it reveals that carbon nanotube with high accessible surface area and good crytallizing degree has potential advantage in the fabrication of EDLCs.关键词：carbon nanotube;electric double-layer capacitors;electrical properties0|2|4更新时间：2025-07-02
- 摘要：A new approach to identify flaw position,size and shape is proposed in metallic materials.In the method,the perturbed magnetic field due to a flaw (crack) is approximated by the magnetic field produced by equivalent coils located at the conductor/air interface.This made it possible for the forward problems in inverse problems to be solved by analytical method instead of numerical methods.The new method is over ten times more rapid than the volumetric integral equation method.The reconstruction computations of a straight and a cross cracks have demonstrated that the new method is correct, efficient and rapid.关键词：flaw identification;equivalent coil;least-squares method;wavelet transform0|2|0更新时间：2025-07-02
- 摘要：How to represent and retrieve reusable software component is always of interest to the reuse community.As a software development environment supporting systematic reuse,JB system chose faceted classification as the primary classification method,with several other methods constituting a combined solution,which supports multiple retrieval methods and their combination.This paper discusses the representation,classification and retrieval of reusable components in JB system,and introduces our assumptions,design rationale,system architecture,data model and features of related subsystems.关键词：software reuse;software component;reuse library;component representation;component retrieval0|2|29更新时间：2025-07-02
- 摘要：In the field of computer vision,it's difficult to acquire disparity distribution from stereo images with monocular cues.In this paper,a "bilateral competition"filter based on cells' cooperation and competition from FACADE theory is presented.This filter applies different competition strategy to monocular cells and binocular cells when cells are cooperating and competing,and then rearranges the activity of the cells to reflect monocular cues and binocular cues.The results show that the approach is feasible to handle monocular cues and it helps us to begin a new method in the field of computer vision.关键词：stereo vision;cell dynamics;monocular feature detection;FACADE0|2|1更新时间：2025-07-02
- 摘要：According to the features of the object-oriented database and its query,the mark-based data operation parallel executing algorithm is proposed,the theoretical analysis and simulation results show that it is an efficient practical algorithm.关键词：object-oriented database;data operation;parallel0|2|0更新时间：2025-07-02
- 摘要：The rapid growth of the Internet makes the research on resource allocation in computer networks a hot area in data communication research field.In the evolvement of the single quality of service to multiple levels of quality of service in Internet,the transmission control protocolb (TCP) will always be the main end-to-end resource allocation scheme.This paper studied the fairness of TCP connections with different propagation delays when competing for resources.It is showed that it is unfair for the connections with large propagation delays in TCP algorithm.When the propagation delays of the connections competing for bandwidth proportionally decrease,the unfairness becomes weaker.This conclusion will be very useful in the renovation of TCP algorithm.Meanwhile,the unfairness property has a promising interest to the design of differentiated services scheme.关键词：TCP (Transmission Control Protocol);propagation delay;throughput;fairness0|2|0更新时间：2025-07-02
- 摘要：On the basis of the generalized fail-safe systems theory and the concurrent error location concept,a new theory of robust fail-safe systems is proposed.A basic robust fail-safe circuit is composed of a basic functional module and an error-locating translator.Such a circuit has concurrent error location capability.Several properties to characterize robust fail-safe circuits are defined.The interconnection conditions,which basic functional modules and translators must satisfy to construct basic circuits with different robust fail-safe properties,are proved.The usefulness of the theory is discussed along with an example of partially robust fail-safe circuits.关键词：fail-safe;robust fail-safe;concurrent error location;error-locating translator;circuit interconnection0|2|4更新时间：2025-07-02
- 摘要：A mathematical model and its corresponding neural network (NN) algorithm for the postal transportation schedule problem is studied.Through analyzing the special characteristics of this schedule problem and the shortcomings of the NN algorithm,a heuristic algorithm is developed.It is proved to be effective by our simulation results.And it can generate acceptable results with good performances.关键词：combinatorial optimization;postal route optimization;postal transportation schedules;neural network0|2|1更新时间：2025-07-02
- 摘要：A new kind of linear registration of multi-modality imaging data by using relativity and periodic curvature function is presented.Experiments prove that this is a new and effective way in the medical image registration.0|2|1更新时间：2025-07-02
- 摘要：A linear output feedback synchronization approach for chaotic Genesio system with application to secure communications is described.A sufficient condition of stable asymptotic synchronization and the boundary of feedback gain is given,based on the linear stability theorem.A computer simulation for secure communication is introduced,and it shows that the receiving and transmitting system can be synchronized quickly and the information can be recovered from the transmission signals with high quality.关键词：chaos synchronization;output feedback;secure communication0|2|6更新时间：2025-07-02
- 摘要：A novel organic electroluminescent device with EuGd complex, (Eu0.1Gd0.9)(TTA)3(TPPO)2,as an emitter is described.The color of the emitted electroluminescence changes with temperature varying from 77 to 300K.This phenomenon is discussed in terms of temperature dependent yields of phosphorescence from the triplet state of the Gd and Eu chelates and the intermolecular energy transfer from Gd-chelate to Eu-chelate cages.The phosphorescent intensities of Gd-chelate and the fluorescent intensities of Eu3+ at different temperature are investigated,and the quantum efficiencies of fluorescence and phosphorescence of EuGd complex are measured.关键词：electroluminescence;rare earth complex;phosphorescence0|2|0更新时间：2025-07-02
- 摘要：The structure of nanoscale metal-oxide-semiconductor field-effect transistor (NANO-MOSFET) is introduced.Its source and drain regions are made of metal and the channel is made of intrinsic silicon.Such structure can effectively avoid short channel effects.Through solving a set of device equations,we simulate and then analyze the basic characteristics of NANO-MOSFET.The results show that the source-drain conductance of NANO-MOSFET changes dramatically when the gate voltage changes.The characteristics is desirable for digital applications,including memory cells.Simulation results also show that NANO-MOSFET can be applied as small-signal analog amplifier if properly biased.关键词：nanoscale device;MOSFET;schottky barrier;thermionic emission;ballistic transport0|2|0更新时间：2025-07-02
- 摘要：In this paper the synthesis procedure of the unequiripple function type impedance matching networks is given for the RC series and parallel load.For example of HFET-1000 chip,using the unequiripple function synthesis procedure,the structure of this network is more simple than that of Chebyshev case,and we may get better gain and stability for this amplifier.关键词：the unequiripple function;impedance matching network;RC type load;compensation procedure0|2|2更新时间：2025-07-02
- 摘要：The degradation and breakdown of thin gate oxide film are related with the generation of traps in oxide layer.In this work,the electric characteristics of 8.9nm thin oxide film have been studied using TDDB (Time-Dependent Dielectric Breakdown) measurement method.In stress experiments,part of the kinetic energy of the injected electrons is dissipated by interaction with SiO2 lattice and converted into some sort of defects in oxide film that behave as traps. When the density of traps reaches a critical density Nbd,the thin oxide film breaks down.Nbd decreases as the area of test MOS capacitor increases.This phenomenon can be explained using statistic theory.Nbd can be used as an oxide quality parameter.关键词：Thin film oxide;TDDB;critical trap density Nbd;trap;charge to breakdown0|2|3更新时间：2025-07-02
- 摘要：The effects of the relative position between the interfaces of pn junction (emitter-base) and SiGe/Si on the current gain and frequency performance of SiGe/Si HBT are investigated by simulation and experiment.It is found that the performance of the HBT will degrade as the two interfaces segregate,and a considerable parasitic barrier will be formed if SiGe/Si interface is only tens angstroms away from pn junction interface towards the base,drastically deteriorating the current gain and cutoff frequency.Based on this,the effects of B dopant segregation and out diffusion in the base of SiGe/Si HBT and i-SiGe spacers are investigated.0|2|0更新时间：2025-07-02
- 摘要：In this paper,the relationship of circuit parameters and the optical bistability swithcing time of silicon photo-electronic negative resistance device is studied.The varying response to low,medium,high-light-input-intensity regions is also studied.There are many kinds of devices in silicon photo-electronic negative resistance device.In this paper,the type of Photo Lambda Bipolar Transistor (PLBT) with resistance load and photo diode load is discussed.关键词：silicon photo-electronic negative resistance device;photo lambda bipolar transistor (PLBT);the optical bistability switching time0|2|0更新时间：2025-07-02
- 摘要：The array processor chip BAP1024 with 0.35m CMOS is designed for real-timing image processing.This paper presents its logic architecture、synthesis process of EDA(Electronic Design Automation) tools、and main performance.关键词：real-timing image processing;deep-submicron technology;array processor chip;floorplanning0|2|0更新时间：2025-07-02
- 摘要：Heterogeneous computing has been widely introduced in high-performance scientific computing as well as in "general purpose" applications due to its higher performance cost ratio.However,the application program is difficult to develop because heterogeneous parallel programming and performance analysis are still empirical.In this paper,Heterogeneous Bulk Synchronous Parallel (HBSP) model is proposed and its cost model is derived.The message passing protocol of HBSP is designed and realized in all kinds of machines which support MPICH package.The FFT algorithm is studied as an example and the experimental results of FFT in several heterogeneous systems are discussed.关键词：heterogeneous computing;bulk synchronous parallel model;parallel computing model0|2|7更新时间：2025-07-02
- 摘要：Based on the double bridge structure of microelectronics test pattern,the method of defect model parameter extraction is presented in this paper.The model parameters include the parameters of defect space distribution and size distribution,which have great importance to simulate and design IC functional yield.关键词：IC;functional yield;parameter extraction0|2|2更新时间：2025-07-02
- 摘要：The aim of time-frequency analysis is to find a density in time and frequency that indicates which frequencies are present in the signal and how they evolve with time.Based on the suppression of cross-term interference in Wigner-Ville distribution,the development history and current and future challenges of time-frequency analysis are reviewed in some detail,together with some successful applications appearing in the literature.关键词：time-frequency analysis;Wigner-Ville distribution;cross-term interference0|2|0更新时间：2025-07-02
- 摘要：In recent years,digital watermarking has been widely used in copyright protection for digital images,audio,video and multimedia products.This paper presents a general watermarking framework (GWF) and fundamental demands.introduces various existing watermark generation algorithms,embedding algorithms and detection algorithms.This paper also presents some efficient watermarking algorithms and several investgative trains of thoughts,and forecasts the application foreground of the digital watermarking.关键词：copyright protection;digital watermarking;multimedia0|2|40更新时间：2025-07-02
- 摘要：A novel fast encoding algorithm is presented for vector quantization.Before encoding,four characteristic values are first computed for each codeword,then four ordered codebooks are obtained according to the ascending order of four characteristic values respectively.During the encoding process,the adaptive searching range and sequence are obtained for each input vector in order to reject a lot of unmatched codewords.The test result shows that this algorithm enables us to search merely 3% to 8% of the codewords to encode an input vector while preserving its coding performance very close to that of the full search method,and the reduction of encoding time is about 93% against full search method.关键词：vector quantization;fast encoding0|2|0更新时间：2025-07-02
- 摘要：This paper first proposes a novel and fast image retrieval framework.In this method,lattice vector quantizer is adopted to quantize and code the feature vectors extracted from images,and the inverted file and Hash table are used to store and index the quantized feature vectors.Fast query can be implemented because of the good geometric and algebraic properties of the lattice.In the end,the performance is analyzed theoretically,and the experimental results are presented.关键词：information retrieval;index;vector quantization0|2|1更新时间：2025-07-02
- 摘要：This paper introduces the idea of resolution to vector quantization technique and analyzes existing vector quantization algorithms according to definition of resolution.In allusion to the demerits about the resolution,a typical resolution modulation method is presented and the corresponding high-resolution algorithms are also given.The experiments give satisfactory results.关键词：image code;high-resolution;vector quantization0|2|1更新时间：2025-07-02
- 摘要：A processing technique based on electrostatic film-posting technology is suggested for preparing electron transmission film at the input of microchannel plate(MCP).The relation between film posting and glow discharge of the gases is discussed,and a 4nm thick electron transmission film at the input of MCP is fabricated for the first time.Experiments show that the electron transmission film contains only aluminum and oxygen elements.The volume resistance and dark current of MCP aren't found to change before and after film posting,while the electron gain increases slightly.关键词：microchannel plate;electron transmission film;image tube0|2|5更新时间：2025-07-02
- 摘要：Network Survivability is an important issue in ATM network.In this paper,after analyzing the procedure of fast restoration,the restoration schedule problem is highlighted.The restoration schedule strategy with priority,P-RS,is presented to solve the problem,with different requirements of restoration time of various services in consideration.The results of simulation show that P-RS could improve the Valid Restoration Ratio to enhance the network survivability.关键词：survivability;valid restoration ratio;alternative routing;restoration schedule0|2|1更新时间：2025-07-02
- 摘要：We present Semantic Chunk Assembling algorithm (SCA) for intelligent abstract system Ladies to simplify the analysis of complex Chinese sentences based on Comprehensive Information Lexicon (CIL) in this paper. CIL describes comprehensive information of words and SCA organizes words of complex sentences into semantic chunks according to the assembling rules. The experimental results indicate that it is quick and effective.关键词：automatic abstract;grammatical and semantic analysis;CIL;semantic chunk assembling0|2|1更新时间：2025-07-02
- 摘要：The paper defines the waveform space,the distance and the limit of waveform on the basis of Boolean process with Boolean operation,and also deduces many properties of waveform and waveform space from the engle of mathematics.Consequently it more perfects the Boolean process.Based on the theory the paper not only defines delay operator,deduces the properties of delay operator,argues continuity of the defined distance but also gives the condition of gateway sensitization and brings forth the outlook of Boolean process.关键词：Boolean process;waveform space;waveform distance;waveform limit;waveform function;delay operator;gateway sensitization0|2|0更新时间：2025-07-02
- 摘要：Different estimation methods of the probabilities of sparse events for the computation of the entropy in large-scale modern Chinese text are applied in this paper.Experiments based on the corpus of four years' People's Daily show that the 0-order,1-order and 2-order entropy are 9.62,6.18 and 4.89 bits respectively.In addition,the influence of such factors as the scale of corpus is also discussed.关键词：entropy;perplexity;statistical language model0|2|0更新时间：2025-07-02
- 摘要：Parallel computation is always a main focus in scientific application domain,and the high performance and easy developing parallel environment is the fundamental for prototyping parallel applications.In this paper,a hierarchical object-oriented parallel application framework is proposed.It is an innovative parallel class library for structured grid applications,and allows for parallel software development in the preferred serial environment and such software to run invariably and efficiently on parallel architectures.关键词：framework;parallel;object-orientation0|2|0更新时间：2025-07-02
- 摘要：The problem of estimating the frequency of a sinusoidal signal in noise is discussesed.Combing DFT transform and interpolation,The frequency of a sinusoidal signal is estimated.The method can improve the accuracy of frequency estimation,and be easily implemented.关键词：frequency estimation;DFT transform;interpolation;mean square error0|2|2更新时间：2025-07-02
- 摘要：D-S evidence theory is a very useful tool in dealing with the uncertainty problems,but its application is limited by the shortcomings of combination rules.Yager had provided some the modified rules,but his rules have some deficiencies.So in this article the new combination rules are proposed which are better than D-S's and Yager's rules in combining the conflicted evidences.关键词：D-S theory of evidence;evidence;combination rules8|5|237更新时间：2025-07-02
- 摘要：This paper presents the theory of neighborhood image processor,and two new modes of the neighborhood function pipeline structure:contract mode and cascade mode.These modes are based on independent image processing algorithms and can fulfill many independent image processing algorithms in real time.They represent the parallel data and parallel processing principles of parallel image processor,and the flexible integration of multiple algorithms.The new modes are best suitable to the requirement of synthetic algorithms by practical problems.This neighborhood function pipeline structure can not only enhance the image processing speed greatly,but also improve the system flexibility.In this paper,the contract mode and cascade mode neighborhood function pipeline structures are discussed and the combination of multiple image processing functions in the function pipeline is presented.关键词：parallel image processing;neighborhood image processor;neighborhood function pipeline0|2|3更新时间：2025-07-02
- 摘要：This paper discusses about low-power state encoding of finite state machines(FSM's) using genetic algorithm(GA).Based upon the probabilistic model of FSM's,GA based parallel searching is implemented in the encoding space.Moreover,area and state transition information may be both included in the 'fitness’ measurement to realize some trade-off between area and power.The test results for some FSM's show that this approach may lead to 20% power reduction.关键词：genetic algorithm;finite state machine;low-power;encoding;fitness0|2|2更新时间：2025-07-02
- 摘要：The lifetime spectra of positrons in SrTiO3 capacitor-varistor ceramics sintered in different atmospheres were measured.The average lifetime decreases with an increase of H2 percentage in sintering atmosphere.More oxygen vacancies are produced in more strongly reducing atmosphere,and more F'-centers are formed because oxygen vacancies will catch electrons.As a result,the lifetime of positron is reduced.The PAT results also show the changes in electron concentration and in energy band structure of samples sintered in different atmospheres.The results were supported by x-ray diffraction analysis.关键词：SrTiO3 ceramics;PAT;sintering atmosphere0|2|1更新时间：2025-07-02
- 摘要：To satisfy the application of diode laser in laser cooling and trapping of atoms,a driver for acousto-optical modulator,whose power and frequency can be controlled by signal,has been made.The adjusting range of power and frequency are 0W to 2W and 54MHz to 120MHz,respectively.To measure the time response of frequency,a method combining F-P and double pass of an AOM is proposed,and time response of power is also measured.关键词：laser cooling;frequency control;output power control;driver for AOM0|2|0更新时间：2025-07-02
- 摘要：Based on RSA public key encryption system,a new software key escrow system is proposed.This new system provides not only effectually anti-flaw in other software key escrow systems,but also satisfies tracing message's sender and receiver,and satisfies other escrow characteristics.So the new approach is established for the software key escrow encryption system.关键词：RSA public key encryption system;key escrow encryption system;software key escrow encryption system0|2|1更新时间：2025-07-02
- 摘要：It was proposed to co-doped erbium and oxygen in a-SiCx∶H or β-SiC with wide band gap in order to realize 1.54μm luminescence of erbium at room temperature.The electronic structure of erbium-related defects in β-SiC were calculated with cluster-model and EHMO theory.and photoluminescence of erbium in a-SiCx∶H were realized (at 77K).The results indicated that a-SiCx∶H or β-SiC could be good host materials for 1.54μm luminescence of erbium at room temperature.关键词：Si-based alloy;Er-O complex;luminescence;EHMO theory0|2|0更新时间：2025-07-02
- 摘要：This paper developed a simple GeSi MOSFET device model,and based on this model,we analyzed the influence of GeSi MOSFET longitudinal structure on device performance.Then the relation of the thickness of cap layer,the carrier density in channel,and the density of delta doped ion on the barrier height Φw of quantum well in channel layer are deduced.Also the relation of the density of delta doped ion,the thickness of gate oxide layer and the thickness of cap layer on the threshold voltage and the relation of the gate voltage on the carrier density in channel are derived.After these analyses,we get several valuable results for our further research.Because of the assumptions in this model,these results are not precise but instructional.In order to get precise results,we simulated the structures of GeSi PMOSFET and GeSi NMOSFET by MEDICI.关键词：GeSi MOSFET;device model;simulation0|2|0更新时间：2025-07-02
- 摘要：This paper presents a nonlinear dynamic large-signal model for GaAs MESFETs with charge sources as elements by way of charge-control methodology.Besides solving the problems of charge non-conservation and current non-consistency under DC and RF conditions,the model realizes the quasi-two-dimensional dynamic analysis considering the temperature characteristics and self-heating effect.关键词：large-signal model;charge-control methodology;self-heating effect;quasi-two-dimensional analysis0|2|0更新时间：2025-07-02
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