最新刊期
卷 33 ， 期 2 ， 2005
- 摘要：Building a human-computer interaction environment that supports natural communication and interaction among participator groups is the key issue of virtual teleconferencing system.We introduced a method that uses multiple projection screens to construct semi-immerse virtual environment,which established the correct space relationship of participators,proposed a watersheds based algorithm for stably real time video object extracted from static background and implemented position based multi-view video reconstruction and synthesizing.关键词：multi-view video;human-computer interaction;virtual teleconferencing;synthesizing2|1485|2更新时间：2025-07-16
- 摘要：The method of the removal of silicon and boron in ultra-pure water by EDI is investigated in this paper.With the investigation of voltage,conductivity of feed water in dilute and concentrate chambers,flux of feed water in dilute,concentrate and electrodal chambers,and pH value,the optimal conditions of silicon and boron removal are obtained.When the silica in feed water is 1000μg/L,the silicon in products can be decreased to 2.66μg/L,which is the best result in our country at present.And with 50μg/L boron in feed water,less than 1μg/L boron in products can be obtained.All these results meet the requirements for ULSI (Silicon:＜3μg/L,Boron:＜1μg/L).2|2781|1更新时间：2025-07-16
- 摘要：Detecting target with low signal to noise ratio is an fundamental technique used for automatic target recognition (ATR) in infrared imagery,and its performances make an ultimate impact on detection sensitivity and effective distance of a system.It is a leading key technique to indicate the ability of recognizing low-observable target in infrared imagery.Adaptive background estimation method is an efficient avenue to complete this task.On the basis of summarizing several current estimation means,a novel morphological filtering algorithm improved properly is proposed in this paper.Some theoretical analyses and experimental results show that this method is able to simplify operation of morphological conversion and to optimize formation of structuring elements.Consequently it can enhance the filtering result and accelerate the speed of operation as well.Moreover it is capable of preserving the property to protect signal characteristic and improving the inherent limitation not to be sensitive on fluctuation of noise and having better ability of adaptive background perception in morphological filtering algorithm.In conclusion this method is concise and efficient.It can provide good filtering results and robust adaptability to image targets with clutter background.关键词：infrared (IR) technique;image analysis;Target Detection;morphological filters4|1804|29更新时间：2025-07-16
- 摘要：Based on the charge control theory,an accurate analytical model for the dc I-V characteristics and small signal parameters of an AlGaN/GaN high electron mobility transistor(HEMT) is developed considering the effects of polarization and parasitic source-drain resistances.Results show that the joint effects of spontaneous and piezoelectric polarization on the performance of the device are highly dominant.The proposed model predicts a maximum saturation current of 1370mA/mm at a gate bias of 2V for a 1.0μm Al0.2Ga0.8N/GaN HEMT.The calculated results also indicate that higher saturation current,transconductance,and cutoff frequency can be achieved by lowering the parasitic resistances.The comparison between simulations and physical measurements shows a good agreement.The model is simple in calculations and distinct in physical mechanism,therefore suitable for design and research of microwave device and circuit.关键词：AlGaN/GaN;high electron mobility transistor;analytical model;polarization;parasitic source-drain resistances4|1798|4更新时间：2025-07-16
- 摘要：This paper proposes a high performance IP routing lookup algorithm based on ASIC implementation. It keeps prefixes of different length in different group associated CAMs, and uses different Hash functions to map the prefixes into the corresponding groups of the CAMs. By this means it reduces the Hash collisions and the memory usage. This scheme can finish the lookup within 1 memory access time and need only few memory accesses for each update in average. With 10ns memory, this scheme can fully match the link speed of OC-768. For its good scalability and parallelism, it can be extended to adapt larger forwarding tables and faster forwarding requirements.关键词：application specific integrated circuit(ASIC);IP routing lookup;scalability;parallelism;OC768 interface;link-speed forwarding2|1099|3更新时间：2025-07-16
- 摘要：This paper presents the hardware architecture for a Content Scrambling System (CSS) that can be used as a building block for DVD-ROM servo controller.It is designed to prevent illegal copy of DVD disc.This includes performing the authentication between DVD drive and the host and scrambling the keys.The system has been implemented in Verilog HDL and the simulation results indicate that the design is successful.Synthesis for a 0.25μm standard-cell library provides an estimation of 100MHZ achievable clock-frequency,1.69mm2 and 37.38mW power dissipation.It has sufficient performance for DVD applications.关键词：CSS(Content Scrambling System);DVD-ROM;Verilog HDL;simulation;synthesis2|998|0更新时间：2025-07-16
- 摘要：The key of security on commercial information systems is to preserve the data integrity within them.Although many integrity principles have been discussed,there is still lack of a systematic commercial secure policy model.A Formal Commercial Secure Policy Model Based on Framework(FB-FCSM) is proposed,which integrates multi-integrity-principle into one systematic commercial secure model.The model has not only good compatibility but also sound scalability,and is a refinement of Clark-Wilson Integrity Secure Policy.关键词：information system security;formal commercial secure policy model;integrity2|905|2更新时间：2025-07-16
- 摘要：An improved model:the segmented and over-issued CRL synthesis model ,which issues certificate status information with certificate revocation list in public key infrastructure,is presented.It is realized by that CRL is segmented first,and then over-issued.Compared to other models,the improved model minimizes the size of CRL which can accelerate to request service,as well as the peak request rate,peak bandwidth,average loads and time piece on CRL repository.The improved model is fit for the large-scale PKIs according to the requirements.关键词：information sacurity;certificate revocation list(CRL);segmented CRL;over-issued CRL;segmented and over-issued CRL;public key infrastructure(PKI)2|843|7更新时间：2025-07-16
- 摘要：This paper develops fuzzy H∞ filter to estimate signal for a class of nonlinear discrete-time state-delayed systems with unknown bounded disturbances.First,the Takagi-Sugeno (T-S) fuzzy model is used to represent the state-space model for the nonlinear discrete-time systems.Sufficient condition for the existence of fuzzy H∞ filter based on T-S fuzzy model is established when modelling error is considered during the design process of filter by S-procedure,which reduces the conservativeness of the design of filter.According to some nature of linear matrix inequality (LMI),the design of fuzzy I∞ filter is turned into the feasible problem of LMI,which can be efficiently solved using convex optimization techniques such as the interior point algorithm.Simulation results show that the proposed design method for filter is effective.关键词：discrete-time systems;H∞ filtering;takagi-sugeno(T-S) fuzzy model;linear matrix inequality (LMI);time delays2|1049|3更新时间：2025-07-16
- 摘要：Text information extraction is an important approach to processing large quantity of text.Maximum entropy provides a kind of framework for natural language processing.A new algorithm using hidden Markov model based on maximal entropy is proposed for text information extraction.The new algorithm combines the advantage of maximum entropy model,which can integrate and process rules and knowledge efficiently,with that of hidden Markov model,which has powerful technique foundations to solve sequence representation and statistical problem,and uses the sum of all features with weights to adjust the transition parameters in hidden Markov model for text information extraction.Experimental results show that the new algorithm improves the performance in precision and recall.关键词：artificial intelligence;text information extraction;hidden Markov model;maximal entropy2|3641|23更新时间：2025-07-16
- 摘要：An adaptive noise cancellation method is presented to extract desired signal from array cross-talk signals, and is used to microphone array speech enhancement.Employing a two-stage filtering system,the method not only has a character of small amount of computations and high stability, but also has no strict limitations to the geometric structure of the microphone array and even to the noise types.Experiment results show that the method is quite effective in speech enhancement as it can cancel a large amount of noise with little distortion to speech signals,and that the method is suitable to many kinds of noisy environments and easy for real-time implementation.关键词：speech enhancement;cross-talk;adaptive noise cancellation;microphone array2|1032|2更新时间：2025-07-16
- 摘要：On the basis of the given pattern,this paper systemically analyzes and researches synthesis method of circular array pattern.Regarding the minimum of the mean distance between given pattern and synthesized pattern as optimization rule,in the case of non-restraint,zero restraint or beam scan restraint,one can respectively gain relevant optimum excitation vectors.Various simulation results show that,this method is simple and efficient on improving the character of circular array pattern.关键词：information processing;circular array;pattern;synthesis2|961|2更新时间：2025-07-16
- 摘要：The paper proposes a hardware/software partition method based on critical path and area prediction.It integrated hardware/software mapping into task scheduling and make schedule more helpful to hardware/software partitioning.The experiments show it is very efficient compared to SA-based method and Path-Analysis method.关键词：hardware/software partitioning;task scheduling;critical path;area prediction;communication synthesis2|1249|1更新时间：2025-07-16
- 摘要：A fully integrated CMOS low-IF weaver receiver working at L-band for DAB (Digital Audio Broadcasting).The receiver takes use of three methods to enhance the image reject performance.Compared with traditional In-phase and Quadrature (I/Q) structure,double quadrature weaver architecture performs higher image reject.An image-reject Low noise Amplifier (LNA) supplies additional image reject in the whole band.The phase and magnitude calibration circuit in LO buffer improves the quadrature of the LO signals.As a result,the receiver can reject the image signal more than 65dB.The cascade noise figure is 4dB and OIP3 is 22dBm.The receiver is fabricated with 0.25μm TSMC CMOS technology.The core die area is 9mm2.It is now under test.2|1296|1更新时间：2025-07-16
- 摘要：In the field of automatic test data generation,a difficult problem is the nondeterminism of program variable,e.g.,array problem and pointer problem.Array variants and pointer variants are defined as a special kind of variants,variants with variable symbol,and a path with variants with variable symbol is defined as a nondeterministic path.Generating testing data of a path is finding an input that satisfies the path constraint condition.By proving the input space satisfying the constraint of a nondeterministic path can be further partitioned into many sub-spaces,the nondeterminism is avoided when test data is searched only in a sub-space in theory.An algorithm is presented to find a sub-space by program slicing.关键词：software testing;nondeterministic path;variant with variable symbol;array and pointer2|927|0更新时间：2025-07-16
- 摘要：Network Information Security includes context security and the anonymous property of Network Communication.Dining Cryptographer (DC-net) Protocol is a famous anonymous communication protocol based on mathematicsally non-solved property.Its main characteristic focuses on that it can avoid being maliciously attacked by providing anonymous information service.After introducing basic DC-net protocol principle,we discuss some problems from engineering view point like how to construct distributed security information service based on DC-net protocol and analyze its run-time problems.关键词：security protocol;formal analysis;e-business;internet;DC(dining cryptographer)-net protocol2|1015|1更新时间：2025-07-16
- 摘要：An optical fiber bi-directional chaos secure communication system is proposed and a model of optical fiber bi-directional chaos communication is presented by coupling the all-light chaos coupling-feedback synchronous system with the injection-light semiconductor lasers and optical fiber channel.The synchronization is numerically achieved in long-haul optical fiber propagation and the system synchronous error is in detail analyzed.Chaotic laser synchronization is mainly limited by cross-phase modulation in the fiber and the propagation nonlinear phase shift is educed.Chaos analog secure communication with a sinusoidal modulation signal of 0.5GHz,chaos digital secure communication with a digital modulation signal of 0.4Gbit/s and 20Gbit/s rates and chaos shift keying secure communication with rate 0.05Gbit/s are numerically simulated,respectively.Relationship between the bit rate and the synchronous error is numerically calculated in optical fiber chaos digital secure communications.The decoding performance and the modulation bandwidth of the system are also analyzed in detail. The system shows the good abilities of robust security and high rate communications. So it could be realized for long-haul bi-directional optical fiber chaotic secure communications.关键词：optical fiber;chaos;synchronization;secure communications2|1423|5更新时间：2025-07-16
- 摘要：Aiming at the deficiencies in fundamental theory of software architecture,especially the deficiency of discovering software architecture style automatically,the EGSA(Extended Granular Computing-Based Software Architecture Model) is built by extending traditional granular computing.The information of component and connector is described as fuzzy set,and multiple fuzzy matrix is used to express structural multidimensional semantic.Furthermore,the mapping between architectures of different level and the synthetic restraint on the property of software architecture are discussed.By the decoding and fuzzy set operation,the EGSA is capable of discovering new architecture style automatically.All above work have set up basic theory of software architecture and provided theoretic goundation for further study.关键词：software architecture;granular computing;information granular;fuzzy set;bipartite graph2|1041|2更新时间：2025-07-16
- 摘要：Support vector machine is a machine study method with good performance when the sample size is small.The method of support vector machine is used to malicious executable in the paper that improves the generalizing ability with given less prior knowledge.Then simulation results express this method has better detection rate,overall accuracy and false positive rate reduced with less training sample size.2|999|3更新时间：2025-07-16
- 摘要：The k-error linear complexity of periodic sequences is one of the important security indices of stream cipher systems.A general computation formula for the variance of the k-error linear complexity of random periodic sequences is given.Some upper bounds,lower bounds for the variance of the k-error linear complexity of random periodic sequences with certain periods are obtained.Furthermore,the exact value of the variance of the k-error linear complexity of a specific random periodic sequence is determined.关键词：stream cipher systems;periodic sequences;k-error linear complexity;expectation;variance2|918|2更新时间：2025-07-16
- 摘要：A new structure element used for operation of mathematical morphology is proposed under inspiration of quantum information processing technology in this paper.The structure element is not simply a liner combination of conventional structure elements.It is a multi-state structure element similar to superposition of states of quantum mechanics.The operators of mathematical morphology using the structure are defined and the meaning of the operation is interpreted.The result attained in processing of digital image using the operators with multi-state structure element can be returned to the result attained by using conventional structure element under special condition.A example of using the structure to detect the edge of binary image is given and the result is compared to that detected by using conventional structure element.关键词：image processing;mathematical morphology;quantum information2|1103|10更新时间：2025-07-16
- 摘要：Denial of service has become a major security threat in open communications networks.Authentication and key establishment protocols usually are vulnerable to network DoS attacks.This paper presents a new countermeasure to make authentication protocols without trusted third party resistant against DoS attack.By using this method,the strength of resistance can be adjusted dynamically and most parallel session attacks can be prevented.关键词：authentication protocol;key establishment protocol;denial of service;proof of work2|947|3更新时间：2025-07-16
- 摘要：Suppose that there are λ departments in a company Ω and any dept.has the right to sign a message on behalf of the company.The group signature made by the dept.should be agreed by the members whose number is over the threshold.The receiver can verify the validity of the signature but can't distinguish which dept.the signature comes from.When the dispute occurs,only the authority can "open" the group signature to distinguish where the signature comes from.Motivated by this consideration,with the combination of vector space secret sharing and subliminal channel technology,a new group signature is presented in this paper.The member can be added or deleted after the scheme founded and the public key length is independent.The "open" process in the presented group signature is realized by subliminal channel.关键词：vector space secret sharing;subliminal channel;group signature2|1696|4更新时间：2025-07-16
- 摘要：An XML-based and ontology-supported Knowledge Description Language (KDL) is first presented,which has three-tier structure(Core KDL,Extended KDL and Complex KDL),and takes advantages of strongpoint of ontology,XML,description logics,frame-based systems.And then,we introduce the framework and XML-Based syntax of KDL,and give the methods of translating KDL into first order logic.At last,the reasoning ability of KDL proved by experiment is illustrated in detail.关键词：ontology;E-commerce;description logics;frame-based systems;first order logic(FOL)2|976|2更新时间：2025-07-16
- 摘要：A group of technologies for sub-100nm process modeling and DFM (Design For Manufacturability) problem are presented.A DFM flow for standard cell design is implemented,with typical DFM patterns being discussed in detail.New design rules and solution styles are introduced as well.Based on the DFM flow and design styles,a set of DFM-friendly 90nm standard cells are designed.关键词：standard cell;design for manufacturability;resolution enhancement technologies2|957|1更新时间：2025-07-16
- 摘要：We propose an adaptive blind watermarking algorithm to embed readable watermark in the wavelet domain.By analyzing the characteristic of detail subband coefficients of the image after Discrete Wavelet Transform,we use the mean and variance of the detail subbands to modify the wavelet coefficients adaptively,and the embedded watermark is invisible to human eyes and adapted to the original image.This is a blind watermark algorithm to confirm the copyright without the original image and the watermark is a meaningful binary image.The experimental results and attack analysis show that the proposed algorithm is effective and robust to common image processing operations and some geometric attacks,such as JPEG/JPEG2000 lossy compression,additive noise,cropping,pixel-shift,and so on.关键词：digital watermark;discrete wavelet transform;blind detection;readable watermark2|1291|12更新时间：2025-07-16
- 摘要：Distributed Virtual Environments that refer to the distributed computer and network systems are usually applied to simulations,especially to the large-scale battlefield simulations.One of their challenging issues is the time-space consistency problem.In recent years,consistency maintenance in distributed virtual environments is well studied by many researchers.The schemes can be summarized as follows:Local Lag,Time Warp,Dead Reckoning,Lock,Token and so on,but they are far from well studied.This paper focuses on the inconsistency caused by the network transport delays.There are three causations that result in the time-space inconsistency in the Environments.To maintain the consistency,this paper proposes the concept "delayed status consistency" and the related methods.Based on the concept,a distributed virtual environment model is proposed to make the methods practical for the simulation applications.The experiment result shows that our methods are suitable for the applications in distributed virtual environments.关键词：virtual reality;large-scale simulation;time-space consistency2|1623|8更新时间：2025-07-16
- 摘要：Partial compensation and complete compensation are two common failure recovery methods for transactional workflows.For complex-structured long running transactional workflows,the compensation cost may be unacceptable since the workflow must be reversed to a previously defined activity or even to the start point to ensure semantic atomicity.We presented a conceptual model for transactional workflow.Based on the model,we proposed a hierarchical failure recovery algorithm.Different from traditional methods,it supports both transactional and non-transactional sub processes,and sub processes of a workflow are nestedly structured.The algorithm determines the end compensation point dynamically in a hierarchical bottom-up manner,so the compensation sphere is confined and compensation costs are reduced.We proved the correctness of the proposed algorithm.Performance analyses showed that it is more preferable than non-hierarchical methods.The algorithm has been applied into InforFlow,a workflow management system prototype.The implementation issues were illustrated.关键词：transactional workflow;failure recovery;hierarchical;compensation2|1154|5更新时间：2025-07-16
- 摘要：This paper builds a kinematics model of the dual-arm six degree of freedom space robot,and deducts the generalized Jacobian matrix which describes the relationship between the motion rate of manipulator end and the rotation rate of joints based on this model.The deducted generalized Jacobian matrix is more simple in its model and demands less work in computation than those deducted by other methods.The formula of the generalized Jacobian matrix is explicit and is easy to solve.We can obtain the generalized Jacobian matrix only if we substitute the parameters of the space robot into the deducted formula of the generalized Jacobian matrix.The method of building the model fits to adopt the resolved motion rate control.This paper gives the simulation to control the dual-arm six degree of freedom space robot based on the resolved motion rate control method.关键词：dual-arm six degree of freedom;space robot;generalized Jacobian matrix2|1137|3更新时间：2025-07-16
- 摘要：The conflict between validity and extensibility can be solved by using a multi-side increase by degrees algorithm(shortened form MIDA) at machine learning in a data set with a feature space of high dimensionality and with large amount of samples that belong to many different classes.In the algorithm,the sample set is divided into several sample subsets step by step by double-point.These feature subsets to match each sample set may be extracted at the same time.The method of different treatment to each sample subset is similas to that facing difficult problems people consider and seek a answer from different emphases and multi sides.The algorithm can classify the difficult problems effectually and raise the extensibility and reduce the complexity in condition of established accuracy.The multi-side increase by degrees algorithm bases on a covering algorithm at machine learning.MIDA is used to classify a date set from Shanghai's stock,and the result is satisfied.关键词：machine learning;covering algorithm;multi-side increase by degrees;feature extraction3|2005|15更新时间：2025-07-16
- 摘要：When using interactive multiple model (IMM) to track targets,to select smaller model set to better cover the movement property and the maneuvering level of various targets and meanwhile to reduce computation complexity are both worthwhile and also necessary research tasks to project implementation.The main work is done through the IMM algorithm of curvilinear model,the construction of angle velocity estimation model and the extension of it to state equations,which make it possible for normal acceleration to be self-adaptively adjusted,hence it reduces the model set to associate only with M curvilinear models selating to tangential acceleration.Computation burden is reduced and algorithm's applying range is extended.The simulation further proves the conclusion.关键词：adaptive interactive multiple model(IMM) algorithm;curvilinear model;turning rate model;target tracking;model set2|1401|7更新时间：2025-07-16
- 摘要：Microwave HBTs' development and application status,equivalent circuit models used in HBTs,its large-and small-signal modeling technique,parameter's extraction methods and research progresses are reviewed.关键词：heterojunction bipolar transisters(HBT);large-signal;small-signal;model;parameter extraction3|931|6更新时间：2025-07-16
- 摘要：Grid resource monitoring is very important to the grid distributed computing environment.A great deal of heterogeneous resource and the status of each node in the grid environment can be achieved by monitoring the system.Analyzing the data gathered by monitoring will help improve the system performance in concrete application.GridFerret Model is a grid resource discovery and monitoring model based on mobile agent,it combines mobile agent technology with grid technology,exerting the advantages of the two technologies to reduce the network traffic during the grid resource discovery and monitoring process.Grid technology and mobile agent technology are introduced in this paper.Then,the design and implementation of Gridferret's architecture is discussed in detail.关键词：grid;monitoring;GridFerret;LDAP;distributed computing2|2569|4更新时间：2025-07-16
- 摘要：Zero-knowledge set is a set that has zero-knowledge quality.The structure of the set makes that a prover can commit to any arbitrary finite set of strings and for any string,reveal with a proof whether a given element is in the set without revealing any knowledge beyond the verity of these membership assertions.In this paper,we propose a new Group Key Distribution protocol based on zero-knowledge set and Peterson commitment so that the identity and number of the group members can be concealed and realize key distribution at the same time.The protocol not only provides a dynamic distribution on a group key,but also guarantees nobody can get additional information about other members except the group key.Compared with previous work,our protocol can provide more security,and is suitable for some special network application,such as secret network meeting.关键词：zero-knowledge set;Pederson commitment;group key distribution protocol2|1212|2更新时间：2025-07-16
- 摘要：Fuzzy lattice based on finite L-context has limit on expansion and time and spatial complexity.Fuzzy-attributes concept lattice in common sense and cut calculation on it were defined to simplify lattice construction.A construction algorithm was presented.Two fuzzy parameters α and on level of concept lattice node were defined to avoid extracting invalid association rules induced by high abbreviation.A case was given to demonstrate the principles for abstracting indefinite rules and computing their support and confidence.A comparison experiment between construction algorithm and Godin algorithm was made.The result shows that construction algorithm is superior to Godin algorithm on time-spatial complexity.关键词：artificial intelligence;fuzzy attribute concept lattice;fuzzy language variable;knowledge discovery2|1420|16更新时间：2025-07-16
- 摘要：The performance evaluation on a triple-layered LEO/MEO/GEO satellite network is carried out by Petri Net-based analysis and software simulation.The GSPN model of a triple-layered satellite network is constructed,and then used to evaluate the network performance with SPNP (Stochastic Petri nets Package) 6.0 software.The effectiveness of the results obtained by Petri Net-based analysis is verified in comparison with these by network simulation using OPNET,and some new results,such as the performance of the triple-layered network is better than that of LEO one under high load,are derived thereby.关键词：satellite communication;low earth orbit(LEO)/medium earth orbit(MEO)/geosychronons earth orbit(GEO) satellite network;generalized stochastic petri nets(GSPN) model;performance analysis;optimum network performance(OPNET)4|1104|3更新时间：2025-07-16
- 摘要：The efficiency of retrieval system is crucial for large-scale information retrieval systems.By analyzing the documents and the users' query logs of a real search engine,a blocking inverted file structure is proposed.Simulation results show that the retrieval algorithm under the new organization of the inverted file can decrease its execution time significantly,and the optimal parameter selection for this blocking organization is discussed.关键词：search engine;information retrieval;inverted file;retrieval efficiency2|2470|2更新时间：2025-07-16
- 摘要：Microprocessor is one of the key technologies of IT industry.This research focuses on multi-level set-associative TLB performance of the general purpose microprocessor.We analyze the performance of different TLB structures using trace-driven simulation,and discuss chip size and design complexity.Above experimental results are applied to Unity-863 environment to get valuable conclusions.It's also applicable for similar processors and system-on-chip.关键词：MMU;TLB;Micro-TLB;Level-2 TLB;performance evaluation2|1280|0更新时间：2025-07-16
- 摘要：This paper introduces a two-hierarchy pipeline structure for FIR filters design.It is a flexible ASIC architecture for user specified symbol rate.By adopting the inner clock several times faster than the input data sampling rate,multiplying and adding component can be highly shared to reduce the area.In light of the number of taps of the filter N and the multiple of inner clock frequency to sampling rate M,N/M-1 taps should be added in the chain of taps in this two-hierarchy pipeline architecture,which separate computations into N/M groups.The two hierarchies of pipeline are in-group with M stages and between-group with N/M stages respectively.As the number of taps of filter increases,the structure can be easily extended without increasing the delay of critical path.This method is flexible and can be adopted in other similar application specific filters design.关键词：DSP(digital signal processing);FIR filter;IC(integrated circuit);pipeline;multiply-add2|1335|5更新时间：2025-07-16
- 摘要：DC-DC converters were considered as one type hybrid dynamic systems (HDS)-switched linear systems (SLS) and the concept of switched linear systems was introduced to DC-DC converter controlled systems.Based on systematical model,output controllability (OC) of DC-DC converters was studied which provides the basis of modern control method application in DC-DC converters.At first,the concept of switched linear systems was introduced and the basic DC-DC converters were built as switched linear system models.Then the output controllability definition and its sufficient and necessary criterion for switched linear systems were given.At last,the output controllability of basic DC-DC converters was analyzed.The simulation analysis and experimental verification of output controllability for Buck converter was given as an example.The analysis method of output controllability for DC-DC converters could be extended to other power converters or all switched circuit to study the output controllability.关键词：DC-DC converters;hybrid dynamic systems;switched linear systems;output controllability2|1185|5更新时间：2025-07-16
- 摘要：A novel combinatorial nonperiodic defected ground structure (CNPDGS) with daul-stopband is proposed.The microwave circuits with the CNPDGS structure are simulated by finite-difference time-domain (FDTD) method.The influences of lattice dimensions on the characteristic of frequency are studied.The filters with daul-stopband formed by microstrip and proposed CNPDGS are designed and manufactured.The curves of the simulated results and measured results are presented.The measured results are in agreement well with the simulated results.For the filter,the pass-band between the two stopbands is tunable.The location and the bandwidth of the pass-band are varied with the sizes of lattice dimension.The distance between two stop-bands can be changed from 3.5GHz to 12GHz.The filter with the expected pass-band can be obtained by the selection of the lattice dimension.The filter with proposed CNPDGS can effectively reject the lower frequencies and higher frequencies in signal.关键词：combinatorial nonperiodic defected ground structure (CNPDGS);stopband characteristic;dual-stopband;finite-difference time-domain (FDTD)2|848|0更新时间：2025-07-16
- 摘要：High energy density self-healing metallized-film pulse capacitor is the key component of inertial confinement laser fusion facility.Generally,the Weibull distribution model is adopted as lifetime distribution to analyze the capacitor reliability,but the results can not satisfy the demands and the cost of tests is very high.By analyzing degradation mechanism of metallized-film capacitor,this paper uses nonhomogeneous compound Poisson process to describe performance degradation process,and then presents a life distribution model of metallized-film pulse capacitor.Using this model,we can analyze the capacitor reliability through degradation data.This technique can not only assess and verify reliability level of the capacitors but also save tests cost.关键词：metallized-film pulse capacitor;reliability;degradation failure;inertial confinement fusion laser facility2|1291|18更新时间：2025-07-16
- 摘要：A new speech sources separation and speaker tracking technique is introduced based on microphone arrays.By means of spatial property of the received speech signals from microphone arrays,this method utilizes beamforming to estimate the DOA of the speaker of interest,and attenuates unwanted voices by nulling other directions.Considering the speech environments where the speaker may freely move and the background voices exist,an adaptive algorithm is used to track the movements and the source direction variations automatically.Computer simulations validate the effectiveness of the technique.Compared with the conventional methods,the scheme needs no training sequence,and have great potential practical advantages.关键词：microphone arrays;speech separation;speaker tracking;beamforming2|1511|3更新时间：2025-07-16
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