最新刊期
卷 37 ， 期 1 ， 2009
- 摘要：The dual-run-length codes are the important technique for test data compression.Test compression has two steps:first,the don’t-care bits in the test data are filled with 0 or 1s and the test data are divided into run sequences;second,every run in the sequences is converted to the compression code according to the given encoding algorithm.However,all the former existing papers focus on the second step,ignoring the importance of the first step thus to lose a certain potential compression ratio.In this paper,we address the importance of don’t-care bits filling to test data compression ratio and propose a novel algorithm,which fills don’t-care bits according to the selecting codes to achieve the higher compression ratio.This algorithm can be used with many dual-run-length codes without impacting on the decoder structure or the chip implementation flow.For the mainstream dual-run-length codes,the compression ratio is improved by 6%-9%.关键词：IC test;test data compression;run-length codes;fill don't-care bits2|1096|6更新时间：2025-07-16
- 摘要：Under the trusted environment,we rethink the three attack abilities defined in the Canetti-Krawczyk (CK) model which is a formal method for the design and analysis of key agreement protocols.We find that under the trusted environment if the signature/verification key pair is generated by TPM,the attacker in the CK model has only one attack ability:session-key query.Otherwise,he has two abilities:session-key query and one new attack ability:long-term private key corruption.In addition,TPM overcomes the weakness of the encryption algorithm based authenticator in the Canetti-Krawczyk model.Based on these,we proposed a new CK model under the trusted environment—CKTC.Thereafter,through an example of utilization of CKTC to design a key-agreement protocol,it can be seen that this formal model predigests the difficulty of the design and analysis a key-agreement protocol under trusted environment.In addition,we find that in order to enhance the security of a key agreement protocol,every country should add their own symmetric encryption modules in the TPM,and a user's signature/ verification key pair should be generated by TPM.关键词：trusted computation;Canetti-Krawczyk model2|1347|2更新时间：2025-07-16
- 摘要：Cooperative diversity could form the virtual multiple antenna array and enlarge the network capacity enormously by sharing the different network users’ antennas.However,only adoption of cooperative diversity can not combat the dynamic variation of network topology and the multipath fading of wireless transmission,for which we should employ both the cooperative diversity and the corresponding adaptive transmission strategy.Accordingly,the optimal criteria to select the cooperative relay among all the candidates is proposed in this paper,based on which a distributed relay selection protocol is presented.An adaptive cooperative transmission scheme is further proposed in accordance with the channle quality between cooperative relay and source node.Besides,closed-form expressions of BER (bit error ratio) for the proposed adaptive cooperation scheme is presented over Rayleigh fading channels.Then,numerical simulations are conducted to compare our scheme with the traditional cooperative diversity,showing the merits of the proposed adaptive cooperative diversity in terms of BER.关键词：cooperative diversity;adaptive cooperation;best cooperative relay;bit error ratio2|1627|11更新时间：2025-07-16
- 摘要：A cooperative theorem based heterogeneous wireless communication mechanism is presented,and key factors impacting on the cooperative diversity of heterogeneous communications are evaluated.An outage probability analysis solution is presented for the second hop with/without time diversity schemes,which is related to the cooperation relay number,the channel gains of the first and the second hop,the normalized power,and etc.Numerical results show that there exists some main facts impacting on the relay channel’s outage,such as diversity mechanisms,cooperative relay number,the second hop’s small scale fading,and normalized power.关键词：heterogeneous wireless communication system;cooperative communication;outage probability2|1156|5更新时间：2025-07-16
- 摘要：Two-hop multiple input multiple output- orthogonal frequency division multiplexing(MIMO-OFDM)relaying communication system is researched.Singular value decomposition is employed to transform MIMO channel on multiple sub-carriers into multiple independent sub-channels in each hop transmission,and the optimal power allocation problem is introduced to maximize system capacity.The power can be allocated jointly on multiple sub-channels at both the source node and relay node,and further,the optimal allocation algorithm is proposed with aid of Lagrange algorithm.Since the optimal algorithm is related to quartic equations and mathematical methods nowadays cannot provide its closed form for the general solution,a method is proposed to utilize iteration courses to realize optimal power allocation,and it provides the upper limit for MIMO-OFDM relaying system capacity.Numeral simulation results show that the optimal power allocation algorithm can improve the system capacity and enhance the transmission ability greatly.关键词：multiple input multiple output;Orthogonal frequency division multiplexing;relaying communication;power allocation2|956|3更新时间：2025-07-16
- 摘要：As a cyber crime platform,botnet is one of the biggest network security threats.Researching the evolvement of botnets,as well as possible botnets construction methods,can improve us in-depth understanding of details of botnets,and also guide us in the botnets defense research.In this paper,we proposed a P2P-based super botnet structure,analyzed the feasibility and discussed all aspects of this new type botnet.Secondly,we evaluated effectiveness of various botnets defense strategies,our simulation results show that,when taking the actual operational conditions into account,it is difficult to completely destroy P2P-based botnets.Finally,we discussed some guidelines for defending against such new botnets.关键词：botnet;peer to peer (P2P);malware;network security2|2183|11更新时间：2025-07-16
- 摘要：This paper builds the Markov fluids analytical model in Relay System where bursty traffic packet arrival process is generated by Markov-modulated Poisson process and the transmission process is described by a phase-type process based on the channel state information.We obtain the system’s probability equilibrium equation and the asymptotic probability distribution of the system queue length using the master function method and get the method to achieve H.We use Maxtix-Geometric method to achieve the analytical expressions of effective capacity and the system’s equilibrium condition.Moreover,the other quality of service(QoS)performance metrics such as average queue length and packet loss rate are derived.The simulated result shows that the theory model and analysis are valid.关键词：relay networks;quality of service(QoS);effective capacity;Markov process;queuing analysis2|1022|1更新时间：2025-07-16
- 摘要：In this paper,a noise predictive equalization scheme is proposed for single-carrier multiple-input and multiple-output frequency domain equalization (MIMO-SCFDE) system,which utilizes a unique-word (UW) as cyclic prefix.The noise in data estimate is predicted by exploitation of the deterministic characteristic of UW and the correlation of the noise at the output of frequency domain equalizers.The predictive results are used to cancel the noises contained in the estimation of the data and enhance the system performance.Based on zero-forcing (ZF) and minimum mean square error (MMSE) criteria,ZF and MMSE noise predictive equalizers are derived respectively.Theoretical analyses show that both of the proposed techniques outperform the conventional frequency domain equalizers.Simulation results have confirmed the significant performance gain they could achieve.关键词：multiple-input and multiple-output (MIMO);frequency domain equalization;noise prediction2|1531|3更新时间：2025-07-16
- 摘要：As mobile nodes dynamically change their locations,Mobile IPv6 offers two methods of multicast services for mobile nodes,which are called remote subscription and bi-directional tunnel,but they both have shortcomings.This paper proposed a mobility prediction based fast and hierarchical mobile multicast architecture (MP-FHMM),which could configure the handoff information by predicting the mobility of the nodes before multicast handoff,and uses the improved FMIPv6 handoff method when mobile nodes are playing handoff.This architecture reduces handoff latency and packet loss rate causing by handoff.In addition,it uses a hierarchical architecture to isolate the subnet movement from outside,which reduces the frequency of rebuilding multicast tree because of nodes’ mobility.关键词：mobile IP;mobility prediction;multicast;fast handoff;hierarchical architecture2|972|0更新时间：2025-07-16
- 摘要：The general processor sharing(GPS)acts as basis for data packet switching and routing algorithms,but the criterions by which to decide processor's service weights for users,who share a same processor,are still unclear.Basing on the principle of equilibrium between users' requirement and service resources availability of networks,a new concept,service quantum which is used to quantify users' need for service resource,is introduced in this paper.The idea of service quantum is further used to improve the General Processor Sharing model toward properly deciding each user's share of the processor power and resulting in an approximate service resources provision balance between users' applications and networks.An application of the improved model in data switch is given thereafter.关键词：Quality of Service;switching;routing;algorithm2|788|0更新时间：2025-07-16
- 摘要：The multi-reference frames technique is employed in H.264,which can improve prediction precision and meliorate video pictures quality greatly.However,the feature calls for higher computational complexity simultaneity.In order to reduce the complexity of H.264 encoder,a fast multi-reference frames selection algorithm is presented in this paper.By considering the correlation and center-biased characteristic of motion vectors in multi-reference frames adequately,the proposed algorithm makes selection for multiple references in advance,thereby it can effectively decrease the numbers of reference frames making full search and improve the coding efficiency.Experimental results show that the proposed methods can improve the speed of motion estimation module by 32.14% on average with less performance degradation and bit-rate increase.关键词：H.264;multi-reference frames;motion vector;center-biased characteristic2|1338|7更新时间：2025-07-16
- 摘要：According to the gray distribution character of vignetting image,the method of Gaussian quadrics fitting based on steepest descent method is introduced in this paper.Parameters of Hesse matrix are also deduced at the same time,and then the problem of irregular Gaussian quadrics fitting is solved.By this method,the whole gray change of image is achieved,so the vignetting phenomenon is corrected.The simulation result illuminated that the parameters of irregular Gaussian quadrics,such as vignetting image gray level,can be estimated effectively by this method.The actual processing result shows the vignetting phenomenon can be removed effectively,and consequently the quality of image is improved.Since no relative optical and geometrical parameters are needed,this method can be widely used in projects.关键词：vignetting;Gaussian quadrics fitting;steepest descent method;Hesse matrix;gray compensation algorithm2|1699|8更新时间：2025-07-16
- 摘要：Automatic video-text extraction is an important field in video content comprehension.In complex background,conventional extraction methods can not robustly locate text nor eliminate interference from background.A robust video-text extraction method is proposed in this letter.First,an unsupervised paradigm based on wavelet is applied to obtain candidate text region.Second,traversing line and its aptitude spectrum is introduced,and text refinement is carried out by extracting traversing line features.At the end,according to the stroke connectivity,MFVL is introduced and applied to obtain key-points in strokes,from those key-points region growth and geometrical restriction is performed to obtain binary text image.Experiment demonstrates that our scheme can extract text with different color,font,size in complex image,and is better than method in Refs. .关键词：wavelet transform;min-max clustering principle;traversing line;heavy line;stroke connectivity2|1477|6更新时间：2025-07-16
- 摘要：An information hiding algorithm based on chaotic grouping is proposed.The entity set is firstly acquired from the engineering graphic,then some operations are executed to the handle of the entities,and the initial values and iteration times are gotten for iteration of the chaotic system.Group operation is processed according to the iteration results,and information hidden is achieved by embedding the same message in the entities in the same group.Simulation results show that the proposed algorithm is robust against the attacks such as modification,rotation,moving and equal scaling.关键词：information hiding;two-dimension engineering graphic;chaos2|957|4更新时间：2025-07-16
- 摘要：Privacy-preserving collaborative filtering aims at protecting participating parties' privacy while providing high-quality recommendations efficiently.In the case of the number of the participating parties is greater than 2,a protocol,employing commutative encryption as its major privacy-preserving technique,has been devised to address the issue of rating a specific item in scenarios with distributed data storage,which is a key challenge in privacy-preserving collaborative filtering recommendation in that scenarios.However,the protocol does not work when the number of the participating parties is exactly 2.Employing secure comparison and secure dot product as its fundamental security infrastructure,we design a privacy-preserving two-party collaborative computing protocol to address the challenge.This protocol produces the same results as the traditional memory-based collaborative filtering recommender systems.Based on secure multi-party computation theory and simulation paradigm,the protocol's security is proved.The protocol's computation complexity and communication cost are examined as well.关键词：privacy preserving data mining;secure multi-party computation;recommender system;collaborative filtering2|1410|11更新时间：2025-07-16
- 摘要：In this paper the entropy preservability of S-Box is discussed and the definitions of condition entropy and entropy preservability of nonlinear S-Box and combining function are presented.Then the sufficient and necessary conditions for judging combining function or S-Box between condition entropy and correlation immunity and the ideal entropy preservability condition of combining function and S-Box are given.Finally,the applied entropy preservability conditions of combining function and S-Box are obtained through analyzing the inherent relation between entropy and Walsh spectrum.关键词：entropy preservability;combining function;S-box;correlation immunity2|745|0更新时间：2025-07-16
- 摘要：To solve the drawbacks of Dempster rule and improved rule of combination,a novel evidence combination method based on proportional conjunctive and complementary pooling criterion was presented.Firstly,the advantages and disadvantages of Dempster rule of combination were analyzed.Secondly,a new mass function based on proportional belief criterion of conjunctive and complementary belief was combined.Finally,the results of numerical examples show that the proposed approach of combination can not only maintain the advantages of original Dempster rule of combination,but also make up for its disadvantages.关键词：evidence theory;Dempster rule of combination;conjunctive and complementary pooling;proportional belief assignment2|1002|5更新时间：2025-07-16
- 摘要：This paper studies the Cramer-Rao Bounds(CRB)for estimating parameters of coherently distributed targets(CDT)using Multi-Input Multi-Output(MIMO)radars.Firstly,the MIMO radar signal model for estimating the CDT parameters is given and the general CRB expression is derived.Then,several CRBs are given in special cases such as a distributed target,a point target and a target with partial information.Thirdly,the CRB properties of MIMO radars are discussed.Finally,the MIMO radar performances are simulated in different conditions through computer simulations.Theoretical analyses and computer simulations show that the MIMO radar is superior to the traditional phased array radar in estimating the CDT parameters because the former has no beam-shape loss.The research conducted in this paper reveals the fundamental performances of the MIMO radars.关键词：MIMO radar;coherently distributed targets;Cramer-Rao bounds2|981|5更新时间：2025-07-16
- 摘要：Coherent jamming to SAR(Synthetic Aperture Radar)is hard to put into practice because of big amount of computation.This thesis has analyzed SAR coherent jamming theory,2-D convolution algorithm for SAR coherent jamming signal generation,and provided a fast algorithm.The computation procedures of these tow algorithms were analyzed in detail,and the simulation was also processed.Both theoretical analyses and simulation results indicated that fast algorithm could reduce complexity and computation amount of azimuth-processing greatly for SAR coherent jamming signal generation.Combining with modern fast digital signal processing technology,this fast algorithm could be used to generate SAR coherent jamming signals sequentially in real-time.关键词：SAR(Synthetic Aperture Radar);coherent jamming;fast algorithm;2-D convolution algorithm2|960|5更新时间：2025-07-16
- 摘要：A method based on a joint block-inner diagonalization (JBID) of a set of output auto-correlation matrices at different delays is proposed for convolutive blind source separation (BSS).A new triply iterative algorithm (TIA) following the gradient descent idea is developed to minimize a novel least squares cost function named tri-quadratic cost function which is used to express the approximation of joint block-inner diagonalization.The mixing matrix can be estimated and the source signals can be retrieved in only one stage through seeking the minimum point of the tri-quadratic cost function by alternately estimating one of the three independent variables parameter subsets combining with the block Toeplitz structure of mixing matrix and the block-inner diagonalization structure of the source signals correlation matrices being fully utilized.Furthermore,TIA is shown to have global convergence even in the presence of the estimation error of the matrix group.Simulations results illustrate that the proposed one-stage algorithm has good convergence and can retrieve the source signals more accurately than some other classic two-stage time-domain methods.关键词：blind source separation(BSS);convolutive mixtures;joint block-inner diagonalization(JBID);triply iterative algorithm(TIA)5|1082|5更新时间：2025-07-16
- 摘要：This paper introduces alpha-stable distribution as additive noise model and generalizes the constant modulus algorithm(CMA).An analytic study of the convergence properties of the generalized CMA(GCMA)is presented.It is shown that the convergence behavior can be predicted and controlled by the combination of initial gains and SIR(Signal Interference Ratio).The special properties of the GCMA are verified by computer simulations.关键词：alpha-stable distribution;constant modulus algorithm;blind beamforming2|1105|9更新时间：2025-07-16
- 摘要：In order to effectively detect ship hydrodynamic pressure field signal from wind wave background,a target detection method has been proposed based on the feature extracted according to the difference of scale wavelet power spectrum between the ship hydrodynamic pressure field signal and the wave hydrodynamic pressure field signal.By means of this method,it is possible to recognize whether target signal is involved or not in received signal.The effectiveness of the method is verified by a real target signal with additive real noise signal,especially under the high sea state and condition of low SNR.关键词：ocean wave;ship;hydrodynamic pressure field;wavelet transform (WT);scale-wavelet power spectrum2|1025|4更新时间：2025-07-16
- 摘要：A new algorithm for discovery and learning of predictive state representations in dynamical systems without reset is proposed.With proving that any landmark can be used as the initial state,the discovered landmarks are used to identify the history at any time step in a continues data,then the conditional probability of any test at any history is estimated using Monte Carlo approaches,which efficiently solves the difficult problem of obtaining the conditional probability in dynamical systems without reset,thereby it is straightforward to discover and learn predictive state representations.The empirical results show that in case of the obtained predictive state representations’s prediction quality,our algorithm has better prediction accuracy than the suffix-history algorithm,which proves the effectiveness of the proposed algorithm.关键词：predictive state representations;dynamical systems without reset;landmark;suffix-history algorithm2|867|1更新时间：2025-07-16
- 摘要：Locally Linear Embedding(LLE)is a sort of powerful manifold learning algorithm.However,LLE is a batch method.If only one new sample arrives,the whole algorithm must run repeatedly and all the former computational results are discarded.In this paper,an incremental locally linear embedding algorithm based on orthogonal iteration method is proposed,which can take advantage of former computational results effectively to process the increasing data sets.Experimental results show the effectiveness of the proposed algorithm.关键词：locally linear embedding(LLE);manifold learning;orthogonal iteration;increment2|1028|9更新时间：2025-07-16
- 摘要：Streaming media is a killer application in the future communication system.The key technologies of the distributed system for streaming media are discussed.The research state based on CDN (Content Distributed Network) and P2P (Peer to Peer) for streaming media is presented.For streaming media based on CDN scheduling algorithms, proxy caching algorithms andinteractive operations are discussed.For streaming media based on P2P data assignment algorithms, incentive mechanism, placement of media objects, multicast technology on the application layer and interactive operations are discussed.Finally, some issues to be further studied are pointed to.关键词：streaming media;peer to peer network;content distributed network.2|2003|14更新时间：2025-07-16
- 摘要：The separation of signal and image content into semantic parts plays a key role in applications such as analysis,enhancement,compression,restoration,and more.Although many approaches have been proposed to tackle this problem in recent years,they have many disadvantages.Morphological Component Analysis(MCA)is a novel decomposition method based on sparse representation of signals and images.The main idea of MCA is to decompose a signal or image into its building blocks considering that there is morphological diversity among a signal or an image’s components,which can be sparsely represented by different dictionaries.This paper introduces the theory of Morphological Component Analysis.Also,it describes the advances on morphological component analysis.Finally,several main problems have been pointed out and further research directions have been anticipated.关键词：morphological component analysis;sparse representation and decomposition;over-complete dictionary2|2838|37更新时间：2025-07-16
- 摘要：The recording technique of microelectrode arrays provides an ideal means for obtaining the large amount of neuronal electric activity,simultaneously.The technique has significant impacts on the intensive investigations for the mechanisms of neurons and their networks,as well as on the development of novel neural prosthetic and therapeutic devices.Utah microelectrode and Michigan microelectrode are two major types of rapidly developed electrode arrays that have been used in neural signal detections in-vivo.In this paper,the manufacture,the structure,the feature and the application of both types of electrode are compared.The principles and methods for the detection and analysis of neural field potentials and unit activity by using the electrode arrays are described.In addition,the challenges and further development in electrode fabrication,in neural signal recording and in signal processing are discussed.关键词：microelectrode array;neuro-electrophysiology;structure;application;field potential;spike2|2261|2更新时间：2025-07-16
- 摘要：In this paper,we consider the problem of minimizing sum power under the constraint of a sum rate in fading Gaussian multiple input multiple output(MIMO) broadcast channel(BC) with additive Gaussian noise.This problem arises frequently in dynamic resource allocation of wireless communication systems.It is the complementary problem to sum rate maximization with a sum power constraint for fading MIMO downlink.We first formulate the equivalent convex optimization problem using the duality between the MIMO multi-access channel(MAC) and the MIMO BC.Then we derive a simple and fast iterative water-filling algorithms based on the subgradient and bisection methods that compute sum power of the transmitter.Theory analysis and numerical simulations show that the proposed algorithm converges to the minimum sum power globally and efficiently.关键词：multiple input multiple output(MIMO) broadcast channel(BC);sum power;dynamic resource allocation;subgradient;bisection2|1327|4更新时间：2025-07-16
- 摘要：Based on the combinatorial double auction theory,a Grid resource allocation model,in which the users and the Grid service providers participate in the combinatorial double auction for resource allocation,is proposed.The model is more suitable for the Grid environment.A novel resource pricing method is proposed to obtain the detailed price information related to the allocation.The simulation results demonstrate that the proposed scheme can carry out the resource allocation and pricing efficiently.Moreover,the buyers with the higher bids and the sellers with the lower bids will get the payoff during the pricing process.关键词：grid;resource allocation;pricing;combinatorial auction;combinatorial double auction2|2093|10更新时间：2025-07-16
- 摘要：Traffic model has been set up for input-queued Crossbar fabric in this paper.Precise definitions for arrive traffic are given according to the cell’s arrive rate,burst and balance.Meanwhile,existence theorems of different kinds of traffic are also provided and proved,respectively.Precisely computing granularity is provided by the burst degree B and the unbalance degree U discussed in the model.The traffic model provided in this paper offers a theoretical reference to the evaluation of scheduling algorithms based on IQ-VOQ scheme.As compared with the self-similarity model in LAN,the Poisson model in WAN and the ON/OFF model of data services,the traffic model proposed in this paper is more adapt to the precise evaluation of scheduling schemes based on IQ-VOQ Crossbar fabric,and therefore the theory reference is provided for designing the switching fabric schemes.关键词：arrive traffic;arrive rate;admissible traffic;burst traffic;balanced traffic2|973|4更新时间：2025-07-16
- 摘要：It is a challenging problem to provide quality-of-service (QoS) guarantees in next generation high-speed network,and the QoS routing is one of the key issues of the problem.For the problem of multi-constrained QoS routing with the inaccurate state information of networks,a critical point model is constructed,and an algorithm based on the depth of the distance vector,MCPSA,is proposed for the problem.The MCPSA aims to select the path with the minimal depth of distance vector from the paths computed by an existing algorithm for QoS routing pre-computation.Theoretical analysis indicates the performance of the algorithm is superior to that of the other algorithm.Finally,extensive simulations are used to demonstrate the efficiency of the proposed algorithm for the problem of multi-constrained QoSR with the inaccurate state information.关键词：multi-constrained path selection;quality of service (QoS);QoS routing;the depth of the distance vector2|873|2更新时间：2025-07-16
- 摘要：A blind reduced-rank multi-user detector(MUD)based on a new variable threshold reduced-rank subspace selection and an improved dimension estimation is proposed.By using the new reduced-rank subspace selection,a proper reduced-rank subspace can be obtained quickly and the subspace can be reused.The improved Akaike Information Criterion(AIC)is adopted to estimate the dimension of the signal subspace in the subspace tracking.The computation of dimension estimation can be reduced by using the criterion in the same error probability.Because AIC has a risk of overestimating the dimension of the signal subspace,the performance of the blind reduced-rank multi-user detector is specially analyzed when the signal subspace dimension is overestimated.The simulation results show that the proposed reduced-rank subspace selection algorithm can achieve the desired system performance with lower computational complexity.关键词：blind MUD;reduced-rank subspace;subspace tracking;variable threshold;signal subspace2|851|1更新时间：2025-07-16
- 摘要：In multi-carrier systems,the most popular of the pilot-aided timing estimators is the one proposed by Schmidl and Cox(S&C),which only one training symbol is used for symbol timing recovery and carrier frequency acquisition.Generally,the proper action of the timing estimator may be strongly affected by the presence of disturbances,like narrowband interference(NBI)signals.This paper investigates the effect of NBI signals,on the timing synchronization for multi-carrier systems.The performance of the S&C symbol timing synchronizer is evaluated in an analytical way in the presence of narrowband interferers.Also,the probabilities of both missing and false detection of a training sequence are addressed.关键词：multi-carrier systems;narrowband interference;symbol timing synchronization;training symbol2|808|0更新时间：2025-07-16
- 摘要：Surrogate model-based evaluation strategy is a main method aiming at solving human fatigue in interactive genetic algorithms.Different substituted individuals are selected in surrogate evaluation strategy will lead to different performance,even divergence.To solve the problem,non-random selection method of substituted individuals based on clustering is proposed.Three kinds of distance,including generalized approximate distance,clustering approximate distance and center approximate distance,are given so as to judge which class individuals belong to.Taking fashion evolutionary design system as an example,simulation results indicate the methods have better stability than random selection method.They effectively avoid misguiding evolutionary process caused by irrational selection.关键词：selection of individuals;clustering;surrogate model;interactive genetic algorithms2|693|3更新时间：2025-07-16
- 摘要：Three time-domain adaptive schemes including time-variance convergence parameter blind LMS(TVCPBLMS),time-variance convergence parameter soft decision weight blind LMS(TVCPBLMS) and time-variance convergence parameter ideal decision weight blind LMS(TVCPBLMS) based on wireless mobile communication OFDM systems for channel estimation are proposed.These novel schemes could trace adaptively the channel characteristic through time-variance convergence parameter and decision weight.Simulation showed that the novel schemes had better performances with high accuracy and fast converges than those of the blind LMS method,especially via different time delay spread,time and Doppler frequency.Furthermore,these schemes are not only suitable in wireless mobile communication systems to estimation channel characteristic but also suitable in radar and spaceflight to estimation the other characteristic parameters.关键词：OFDM systems;channel estimation;blind method2|1186|3更新时间：2025-07-16
- 摘要：In this paper,we investigate the effect of imperfect channel state information (CSI) on the capacity of multiple-input multiple-output (MIMO) systems.A design of variable power adaptive modulation using imperfect CSI,subject to an average power and BER constraint,is proposed.Based on the statistic distribution of Wishart matrix,we derive the capacity expression of such systems in a closed-form.The results show that our design is more robust to CSI imperfections than the system designed under a perfect CSI assumption.关键词：multiple-input multiple-output (MIMO);channel state information (CSI);adaptive modulation2|1070|1更新时间：2025-07-16
- 摘要：Sensor nodes can be compromised by attackers and inject large amounts of bogus data to exhaust network resources.A practical traceback mechanism is proposed,in which each forwarding node marks packets with a certain probability.By collecting enough packets,sink node will construct a path back to the source node.It is proved that the mechanism is secure against all forms of attacks and other two marking methods are proposed to improve the performance of the mechanism.Simulation results show that the mechanism is efficient and practical.关键词：Wireless sensor networks;security;traceback2|1125|11更新时间：2025-07-16
- 摘要：A novel particle-pair cooperative optimizer(PPCO)is proposed for speaker identification based on vector quantization.In this algorithm,two initial particle-pairs simultaneously explore for the best speaker codebook,and each particle-pair which consists of two particles performs basic operations of particle swarm optimization(velocity updating and position updating)and conventional LBG algorithm in sequence at each iteration.Information is exchanged when particle-pairs are reorganized periodically.And then two elitist particles selected from two initial particle-pairs respectively continue to move toward the global optimum.Experimental results have demonstrated that the performance of this new algorithm is much better than that of LBG,FCM,FRLVQ-FVQ,FEP and PSO consistently with lower speaker identification error rates,shorter computational time and higher convergence rate.The dependence of the final codebook on the selection of the initial codebook is also reduced effectively.2|1115|0更新时间：2025-07-16
- 摘要：The filter system is the most pivotal part of the digital audio equalizer;its precision and effect influence the whole audio equalizer performance.In this paper a new design method for audio equalizer is proposed,that is digital audio equalizer system based on Field Programmable Analogy Arrays (FPAA) of switch capacitance technology.With this method,the audio equalizer system will be greatly enhanced in convenience,efficiency and performance ,low cost.The frequency responses of Elliptic function filters of switch capacitance is very closely to the ideal sound styles frequency response curves,which is a good system of the audio equalizer filters.With the further development of switch capacitance technology,current model and voltage model technology,FPAA will expect a considerable development and wider application in medical,instrument,senior audio,automatic test equipment,communications and motor vehicle etc.关键词：audio equalizer;field programmable analogy arrays (FPAA);filters;simulation3|1501|2更新时间：2025-07-16
- 摘要：Stochastic Resonance(SR)is getting more and more attention in recent few years,as it can be used as a tool of using noise to enhance output signal-to-noise-ratio.One of the key problems is how to design a simple and efficient SR system.As for the weak signal detection,we analyzed two-state quantizers and two-state quantizer arrays,deduced the optimal two-state quantization detector and asymptotic optimal array SR detector,and gave out the designing criterion of asymptotic optimal array SR detector.According to the theoretical analysis,we designed a robust array SR detector and parameter selection algorithm based on noise sample collection,which can achieve good detection performance even the ambient noise is unknown.关键词：weak signal detection;stochastic resonance;nonlinear systems;non-Gaussian noise2|1184|17更新时间：2025-07-16
- 摘要：An H.264-based packet loss resilient intra refresh algorithm is presented in this paper.Firstly,the intra-refresh matrix is created to record the dependent relation of the blocks in the current frame to that in the reference frame.Secondly,based on intra-refresh matrix,an end-to-end rate distortion(ME2ERD)model for packet loss network is proposed to estimate the motion mode of a block.Then,by using supplemental enhancement information(SEI)domain,an adaptive intra refresh method is achieved to reduce the quality degradation due to error propagation.Compared with random intra refresh method,the proposed technique can improve the video quality more than 5dB over variable and error-prone channel.Furthermore,this algorithm is compatible with H.264 without any increasing channel burden and arithmetic complexity,and can be used in practice.关键词：packet loss resilience;intra refresh;SEI domain2|1389|1更新时间：2025-07-16
- 摘要：A linear iterative method for projective reconstruction based on rank 1 matrix containing the images of all points in all views,which can deal with all the images in a unified manner,is presented in the paper.In the method,the unknowns are the 3D motion and relative depths of the set of points,not their 3D positions.The coordinates of the points along the camera plane are given by their image positions.The knowledge of the coordinates enables us to solve the projective reconstruction problem by the linear iterative method based on the rank 1 matrix.Experiments with both simulated and real data show that the method for projective reconstruction has good property of convergence,computational cost and projective errors.关键词：projective reconstruction;linear iteration;rank 12|1039|4更新时间：2025-07-16
- 摘要：Optimization calculation is one of the important application fields in Neural Network.This paper proposes a Neural Network computational method of nonlinear programming problems based on precise F-function for the problems of not catering to network size,computational efficiency and accuracy when solving the constraint nonlinear programming problems in current Neural Network.A low order precise F-function of constraint nonlinear programming problems is served as energy function of Neural Network.The dynamics equation of Neural Network is constructed and the clarification of its stability is given by the most rapid decreasing principle of the energy function.Theoretical analysis and computational example emulation show that the proposed Neural Network dynamics equation globally and precisely constringes a local optimization solution of the original programming problems.In particular,the neural network dynamics equation is easy to be mapped as dynamic circuit,which is a Real-time calculation method for engineering optimization problems.关键词：neurocomputing;nonlinear programming;exact penalty function;dynamics equation;real-time calculation2|1824|2更新时间：2025-07-16
- 摘要：In this paper,a novel joint channel estimation and symbol detection algorithm is proposed.Based on the idea of generalized distribution law,the likelihood function which is used to achieve the optimal sequence detection is factored into products of several terms of local probability function.An intuitive factor graph is adopted to describe the relationship of these terms.Then a distributive joint channel estimation and symbol detection method is deduced by applying sum-product algorithm on the factor graph directly,which approximates the performance of optimal sequence detection with low computational complexity.Meanwhile,particle filter is introduced to solve integrals of continuous variables in the algorithm,by which a real-time channel tracking is presented.Thus the demand for pilot symbols can be reduced and the spectrum utilization efficiency is improved.Simulation results show that the new algorithm can achieve good performance with low computational complexity.关键词：symbol detection;channel estimation;factor graph;sum-product algorithm;particle filter2|1177|4更新时间：2025-07-16
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