最新刊期
卷 40 ， 期 4 ， 2012
- 摘要：In this paper,based on the smart home system as one of the most typical applications of wireless multimedia sensor networks,we abstract the system model.In order to provide multimedia data in the network to the user quickly and easily,we design a gateway in smart home system to support the interconnection with heterogeneous networks.We use HDLC (High Data Link Control) protocol to guarantee reliable data transmission in the design of the gateway access to the PSTN,and implement the HDLC protocol based on FPGA.In order to improve the processing efficiency of HDLC chip,receiving buffer is designed as a multi-Block FIFO and supports to read and write multiple Blocks concurrently.The multi-Block receiving buffer includes the independent BRAM mode and shared BRAM mode to adapt to a variety of requirements and reduce the CPU interrupt effectively.Modelsim is utilized to simulate the function of FPGA-based HDLC chip to verify reading and writing,transmitting and receiving,time slot,interrupts and other functions.Finally,verilog code runs in the actual test board and the FPGA-based HDLC chip is verified on the test board.关键词：multimedia sensor networks;smart home;gateway;high data link control (HDLC);field programmable gate array (FPGA)3|3|7更新时间：2025-07-16
- 摘要：According to the trajectory tracking control of a car-like mobile robot,a sliding mode tracking control scheme is presented in this paper.An equivalent control law is obtained by using PI-type sliding surface and a switching control law is gotten by replacing sign function by variable rate function.The stability of the system is proved by Lyapunov theory.Simulation results demonstrate that the proposed strategy can not only track any reference trajectories,but also greatly reduce the chattering phenomenon of the system.Even though external disturbances exist,the proposed approach has a satisfactory control quality.关键词：car-like mobile robot;trajectory tracking;sliding mode control2|2|16更新时间：2025-07-16
- 摘要：This paper presents a point pattern matching algorithm based on local relative shape context and Q-spectra of line graph.A line graph is constructed for each point,and the spectrum decomposition is performed on the signless Laplacian matrix of line graph.The eigenvalues(Q-spectra) obtained from the spectrum decomposition are used to represent the point's feature,and the initial matching probability is calculated.Local relative shape context is defined to compute the similarity distance between any two points.Q-spectra method is combined with local relative shape context via a probabilistic relaxation approach to get the matching result.Experimental results indicate the effectiveness and feasibility of the proposed algorithm.关键词：line graph;Q-spectra;local relative shape context;probabilistic relaxation;point pattern matching2|2|4更新时间：2025-07-16
- 摘要：A Gabor wavelet and Memetic algorithm based face recognition technique named MA-Gabor is proposed in this paper.MA-Gabor can attain more distinctive features with less computational time by using particular Gabor wavelet filters in the feature extraction on specific areas of the face image.The Memetic algorithm is introduced in optimizing the Gabor wavelet filters' design in MA-Gabor.Experimental results show that the Memetic algorithm can achieve better design than conventional optimization approaches.The MA-Gabor algorithm,using optimized Gabor wavelet filters in feature extraction,attains higher recognition rate than state-of-the-art face recognition techniques.关键词：face recognition;Gabor wavelet;memetic algorithm2|2|12更新时间：2025-07-16
- 摘要：Due to the fact that GIS(Geographic Information System) could provide high-resolution image with commercial observation satellites,this commercial availability of unprecedented and timely information and images of the earth poses significant threats to national security.Since existing access control models could not avoid the information inference according to the authorization results,a privacy-preserved RBAC for Raster Data is proposed,in PPR-RBAC,fake objects are made to protect sensitive raster objects,and authorization mechanisms are contributed for user to access sensitive raster objects by sensitive object activation.In conclusion,PPR-RBAC is formally proved to be safe and it lays the groundwork for the security deployment of PPR-RBAC in GIS.关键词：GIS;raster data;sensitive information protection;data counterfeiting;sensitive object activation2|3|0更新时间：2025-07-16
- 摘要：Based on the field-emission theory,the wear of electrode materials and the work energy were studied, and the single-hole EDMing contrast experiments with different process parameters were designed and carried out.The analysis on experimental results show that,copper electrode has the higher discharging energy,higher machining efficiency but lower material wear comparing with A3# steel ones;the carbon deposition layer on the end surface plays a better role in reducing the wear of copper electrode while has little effect on A3# ones;and to copper electrode,the bigger ratios of valid discharging time will be helpful to improve the machining efficiency,lower the wear of electrode,but the wear-reducing function of carbon deposition layer will recede either.关键词：EDM;wear of electrode material;carbon deposition layer2|2|5更新时间：2025-07-16
- 摘要：Communication protocol reverse engineering of malwares is significant base for various network security applications.However,recent works have limited accuracy and integrity in identifying protocol fields and are especially weak in understanding fields' semantics.This paper proposed a method for communication protocol reverse engineering based on dynamic taint analysis.By building an extended taint propagation graph (ETPG) recording both instruction and function level behaviors of a malicious process,dividing the protocol data into different syntax fields and inducing the semantic information of individual fields were achieved.A prototype system was implemented and evaluated with malware samples.The results show that this method can divide the syntax fields and extract semantic information accurately and effectively.关键词：malware;protocol reverse engineering;dynamic taint analysis2|2|8更新时间：2025-07-16
- 摘要：As a new variant of the hypercube,the exchanged hypercube reduces the cost of topology connecting when the scale of networks increases.According to the graphic definition of Exchanged Hypercube,in this paper,we obtain its formulized definition,prove that the subgraphs of exchanged hypercube are isomorphic to hypercubes,propose the concepts of EHS(s,t) and EHT(s,t),and on the basis of these concepts,prove that there are only even circles with length no more than 4,and that the vertex connectivity and edge connectivity of exchanged hypercube are both min{s+1,t+1}.To enlarge the application range of the exchanged hypercube,we put forwards three strategies embedding hypercubes into exchanged hypercubes as well,and prove that,when n=s+t+1,Qn-1 can be embedded into the exchanged hypercube EH(s,t) homeomorphically.关键词：interconnecting network;exchanged hypercube;hypercube;connectivity;isomorphic;homeomorphic;embedding2|3|4更新时间：2025-07-16
- 摘要：In many fields,data stream continues to grow in terms of generation speed,scale and vibration,which makes the data stream mining more difficult.RCSW is used in data stream mining to finish data steam sampling.The three concept such as real-time T,key time point set,data stream processing ratio are proposed.Then an algorithm for data stream speed anomaly detection is proposed,which monitor and predict flow velocity.The system intelligently adjust ring buffer and data stream processing ratio if there is excessive flow velocity,in order to solve the conflicts commendably between data processing power and flow velocity,throughput and limited memory.Experimental results show that it is an algorithm for data stream speed anomaly detection which can ensure normal execution of data stream mining and well meet the need of the system real-time.关键词：data stream;ring circular sliding window (RCSW);time point;real-time T2|2|1更新时间：2025-07-16
- 摘要：Watermarking algorithms in general only have single function,and dual watermark algorithms have interference problems between the two watermarks.To address these issues,this paper proposes a mutual support dual watermark algorithm.Firstly embed robust watermark in the image,and then divided the image into blocks,extract measurement matrixes from the key of the robust watermark and observe each image block using these matrixes in accordance with the compressive sensing (CS) theory,the measurements are the semi-fragile watermark which will be registered as a zero-watermarking.The use of zero-watermarking can reduce the impact of visual effect on the original image by dual watermark,and effectively avoid the interference problems.The introduction of CS theory realizes the interaction between the two watermarks.On the one hand,the robust watermark provide measurement matrixes and secrecy support for the semi-fragile watermark,on the other hand,the semi-fragile watermark can Enhance the robust performance of the robust watermark and verify the authenticity of its key.关键词：digital watermark;compressive sensing (CS);dual watermark;zero-watermarking;singular value decomposition (SVD)2|2|8更新时间：2025-07-16
- 摘要：In directional sensor networks,the coverage of the target region can be enhanced by adjusting the sensing directions of nodes.A greedy iterative algorithm of coverage enhancing problem in directional sensor network is proposed.In each iteration,the sensing directions of those nodes that can most increase the coverage are adjusted.This iteration process is repeated until the coverage cannot be increased by adjusting the sensing direction of any node.Moreover,a computational geometry method for region calculations in this algorithm is proposed to improve the computational accuracy and reduce the computing time.Extensive simulation results have shown that this algorithm has fast convergence speed and short execution time.And it outperforms existing algorithms with respect to the coverage of the target region.关键词：wireless sensor network;directional sensor node;coverage enhancing;greedy algorithm;iterative algorithm2|3|7更新时间：2025-07-16
- 摘要：Due to the sale-free and small-world characters of Protein-Protein Interaction (PPI) network data,current clustering algorithms did not perform well.According to the topological structural characters of PPI networks,this paper proposed an ant colony optimization clustering algorithm based on joint strength (JSACO).This method modified the pickup/drop rules of ACO algorithm by means of introducing the concept of joint strength,which regarded the joint strength as pickup rule to cluster the protein nodes.In addition,the protein nodes which had the low joint strength were abandoned in accordance with drop rule and the final clustering result was obtained.Finally the PPI data in MIPS database was used to test the algorithm and the clustering result was compared with other PPI clustering methods.The simulation results show that JSACO algorithm performs better in terms of precision value and consumes less time.关键词：PPI Network;joint strength;ACO algorithm;clustering2|2|10更新时间：2025-07-16
- 摘要：This paper investigates the network lifetime optimization issue for two-hop cooperative Orthogonal Frequency Division Multiplexing (OFDM) systems recruiting multiple relays.In order to maximize the network lifetime,we propose an exhaustive algorithm which takes energy pricing concept into account.Specifically,all possible combinatorial strategies of subcarrier pairing and relay selection are firstly formulated and by applying standard Lagrange technique,the optimal power assignment which minimizes the total energy consumption subject to network throughput constraints,can be theoretically derived.Accordingly,the candidate with smaller energy sacrifice is designated as the optimum solution.Since the real world applications of the proposed approach are restricted by prohibitively high computational complexity,two low complexity alternatives are consequently designed based on the price of unit Signal-to-Noise Ratio (SNR).The essence of these methods is that relay selection and subcarrier pairing are optimized in two steps.Simulation results indicate that,the network lifetime performance of the proposed algorithms significantly outperforms the existing schemes.关键词：orthogonal frequency division multiplexing (OFDM);power allocation;relay selection;subcarrier pairing;cooperative communication2|2|1更新时间：2025-07-16
- 摘要：Traditional Ad Hoc network routing protocols are mainly based on the condition "Shortest Path",and possibly form many congestion nodes to cause routing instability and re-routing.To this point,this paper proposed a new bio-inspired adaptive routing protocol (ATAR) based on a mathematic model ARAS which is originally a model for its host Escherichia coli cells to adapt to changes in the availability of a nutrient.In this paper,queue buffer of routing node and hop count of feedback are defined as a new metric,fitness,which represents the comprehensive factor of congestion level and the length of routing path.We map the fitness of neighbors of routing node to the cell volume growth speed in the improved ARAS model,and calculate the state values of neighbors with the model.Then,the routing node selects the next hop according to the maximum.Using this method,we can adaptive to choose a leisurely node as the next hop with shorter path.关键词：bio-inspired;adaptive;congestion;routing protocol;Escherichia coli2|2|0更新时间：2025-07-16
- 摘要：Providing fairness performance for traffic flows is an important requirement for today's routing and switching equipments.To meet this requirement,we first discuss the feasibility of implementing flow scheduling in this paper.Then,based on the discussion,it comes up with a layered and hybrid fair scheduling (LHFS) scheme.LHFS is a hierarchical and hybrid algorithm for CICQ (Combined Input and Cross-point Buffered) switches.With LHFS,each input and output port can schedule variable length packets independently with a complexity of O(1).Theoreuical analyses show that LHFS can provide delay up-bound and fair service guarantees.Finally,we implement LHFS in SPES (Switch Performance Evaluation System) to verify the analytical results.关键词：buffered crossbar;scheduling policy;fair service;layered and hybrid2|2|0更新时间：2025-07-16
- 摘要：Due to the limited sensing range for sensors,moving target tracking has to be realized by relaying from one sensor to the other in sensor networks.Thus,the tracking procedure can be modeled as a Markovian chain system.By reconstructing the innovation equation,the relaying Kalman filter(RKF) algorithm is designed in the light of the Bayesian theory.On this basis,the interacting multiple sensor filter(IMSF) algorithm is proposed further by mixing the initial state and covariance at one cycle,which has a bit better tracking performance than the RKF algorithm,but at the cost of the computational complexity.Finally,simulation results show the effectiveness of the proposed algorithms.关键词：sensor networks;Markovian jump system;target tracking;collaborative tracking4|2|4更新时间：2025-07-16
- 摘要：A real-time frequency selection system based on backscatter sounding and interference monitoring for the short-wave communication is developed in this paper.Using fast sweeping-frequency and backscatter ionogram auto-scaling techniques,the usable frequency range is obtained,and,the clean channel is obtained simultaneously by interference automatic analysis technique based on time-availability.Then,the real-time communication frequency is selected by the fusion of the two kinds of information above.Some test results of specific communication links are given and further analysis of special cases is presented.The experimental results show the effectivity of the proposed system.关键词：HF backscatter sounding;interference monitoring;shortwave communication;real-time frequency selection2|4|3更新时间：2025-07-16
- 摘要：In order to improve the accuracy of fault diagnosis for dynamic system,and reduce the diagnosis influence from operating environment,a new fusion method in multiple classifier system based on dynamic weight is proposed.The new approach dynamic assigns weights to base classifiers according to their classification accuracy and decision support value.Bigger weights are assigned to more reliable decision output,and the weights of unreliable outputs are close to zero.In this sense,a subsystem is used to make final decision instead of system.Experimental results demonstrate that the new fusion method can get good fault diagnosis performance,and it can get higher accuracy than single classifier and some common used fusion methods.关键词：fault diagnosis;multiple classifier system;data fusion;decision support value;dynamic weight2|2|2更新时间：2025-07-16
- 摘要：Privacy protection is indispensable in data mining,and many PPDM (privacy-preserving data mining) methods have been proposed.One such method based on data perturbation is SVD (singular value decomposition)-based method,which treats all samples and attributes equally.However,different samples and attributes may have different requirements for privacy protection,and may be not equally important for data mining.So,it is better to treat them differently.This paper proposed an improved SVD-based perturbation method,which can perturb different samples and attributes to different degrees.In addition,this paper proposed an improved privacy-preserving classification mining method using this improved SVD-based perturbation algorithm.The experiments showed that while maintaining data utility,the proposed privacy-preserving classification mining method can protect privacy better than the original SVD-based method.关键词：privacy preserving;data mining;singular value decomposition2|2|11更新时间：2025-07-16
- 摘要：Based on the sixth type of covering-based rough set model,covering semantics of modal logic S4 is proposed.The reliability and completeness theorems with respect to covering semantics are proved by means of the relationships between covering model and Kripke model.Moreover,the relationships between covering semantics and Alexandrov topological semantics are also discussed.It is proved that covering semantics and Alexandrov topological semantics are harmonious and consistent.关键词：modal logic;covering semsntics;Kripke semantics;topological semantics;completeness2|2|0更新时间：2025-07-16
- 摘要：The traditional trend of DNA computing aims at solving computationally intractable problems in the filed of graph theory and permutation and combination.For the objective to solve the Ménage problem with biological operations,this paper gave a mathematical model and analyzed the difficulties of solving the problem with DNA computation.An improved mathematical model of the Ménage Problem to overcome these difficulties was proposed.In order to improve the efficiency,using the extended separation and extended multi-separation operation,this paper proposed a sticker DNA algorithm of the Ménage problem and analyzed the complexity of the algorithm.Consequently,it showed the operation steps and carried out simulation experiments by an instance.关键词：DNA computing;circle permutation;Ménage problem;sticker model2|2|1更新时间：2025-07-16
- 摘要：To solve the problems of the multiple nodes,redundant data and unstable structure in traditional road-network models,a road-based model based on traffic network features and human's understanding of the road network,is constructed in this paper.In this model,the traffic and spatial attributes of the roads are expressed in detail,and traffic network is described by road intersection relationship.On the basis of lessening data and simplifying model structure,an improved A* algorithm is proposed.The results of the simulation experiment show that the proposed model and corresponding optimal path searching algorithm meet the needs of practical applications,besides,certain advantages can be found in storage cost of the model and search efficiency of the algorithm.关键词：intelligent transportation system;road-based model;improved A* algorithm2|2|1更新时间：2025-07-16
- 摘要：This paper proposes a new single-channel speech separation method based on sparse decomposition.The new method is based on the construction algorithms of quasi-KLT bases proposed in this paper.First,it is proved that based on the ideal quasi-KLT bases generated from the sources,both sources can be perfectly separated from a single mixture by l exp(0) optimization.Then,considering the fact that the ideal quasi-KLT bases cannot be obtained in practice,orthogonal matching pursuit (OMP) template-matching quasi-KLT bases generated from the single mixture are first proposed,and then perform single-channel speech separation by l exp(0) optimization using the OMP template-matching quasi-KLT bases.Finally,simulation results demonstrating the perfect separation of both sources from a single-channel speech mixture by l exp(0) optimization using ideal quasi-KLT bases,as well as the effective performance of single-channel separation of two speech sources using the OMP template-matching quasi-KLT bases are presented.关键词：speech separation;sparse decomposition;l exp(0) optimization;orthogonal matching pursuit (OMP);Karhunen-Loeve transform (KLT)3|3|5更新时间：2025-07-16
- 摘要：We propose a new multiscale image representation based on OSV model.We obtain with OSV model,in which we give single scale decomposition.Then we give a hierarchical adaptive representation for the different features in images by iterating OSV model for different monotone scale parameters,applying the decomposition to the residual information of the previous step.The result multiscale decomposition is nonlinear.We discuss the numerical discretization of the new method.The numerical results show an excellent decomposition effect and significant improvement over Nezzar method.关键词：multiscale decomposition;OSV model;variational minimization2|3|1更新时间：2025-07-16
- 摘要：A novel image classification method based on sparse coding and multiple kernel learning is proposed in the paper.Traditional methods of image classification used common sparse coding but lose the spatial information.We add this spatial information by dividing the image with the spatial pyramid.With the nonlinear SVM for image classification,each level of spatial pyramid has its own kernel,and we adopt machine learning for the optimal trade-off between different kernels.A much more discriminative kernel can be seen as the linear combination of base kernels corresponding to different pyramid levels.The experiments on the benchmark dataset show the effectiveness and robustness of our method.The precision on scene categories dataset can reach 83.10%,and it is the best result comparing to the state-of-the-art work.关键词：image classification;multiple kernel learning (MKL);sparse coding;spatial pyramid2|2|24更新时间：2025-07-16
- 摘要：In order to explore dimensionality reduction and classification in hyperspectral remote sensing image,an algorithm based on semi-supervised marginal Fisher analysis(SSMFA) and k-nearest-neighbor simplex(kNNS) is proposed in this paper.First,the data are projected from a high-dimensional space onto low-dimensional space by SSMFA combined with the information of different classes.Then,classification is performed under the kNNS classifier by using a few neighbors from each class.The experimental results on the Urban data set,Washington DC Mall data set and Indian Pine data set show the effectiveness of the proposed algorithm,when i(i=4,6,8) labeled samples and 10 unlabeled samples of each class are randomly selected for training and 100 samples of each class for testing,the overall accuracy of our proposed algorithm is improved by 0.8%-2.5%,2.8%-4.5% and 4.0%-7.0%,respectively,as compared with MFA+kNNS,MFA+kNN and other methods.关键词：hyperspectral images;land cover classification;graph embedding framework;nearest neighbor2|3|7更新时间：2025-07-16
- 摘要：Constrained Energy Minimization (CEM) algorithm is very sensitive to spectral difference of the same object and cannot detect the large targets.We proposed a sample weighting CEM algorithm.Through spectral vector unitization,the errors caused by different environment are decreased,and target recognition accuracy is increased.To decrease the proportion in the sample autocorrelation matrix,we use spectral correlation as a similarity measure to weight the samples.The modified algorithm acquired the satisfied effect for large targets.关键词：target detection;constrained energy minimization;spectral vector unitization;sample weighting2|2|3更新时间：2025-07-16
- 摘要：A high-resolution SAR image target feature extraction method based on Separate Ensemble Empirical Mode Decomposition (SEEMD) is proposed in this paper.Firstly,target scattering function is obtained in the image wave-number domain via SEEMD.Then the target scattering feature parameters are estimated,we can classify targets into different scattering types by these parameters.The computer simulation and the real data experiment show the validity of the method.关键词：high-resolution SAR image;feature extraction;empirical mode decomposition2|2|0更新时间：2025-07-16
- 摘要：To deal with the degradation of the conventional range alignment algorithm under low SNR,an ISAR (Inverse Synthetic Aperture Radar) range alignment method is proposed based on iterative weighted least squares fitting.Utilizing the stationary moving characteristic of the target,the proposed method make alternatively iterative update of both the range migration and the weighted matrix,thus realizing the range alignment based on the estimation of the parameters of the target motion.The simulation demonstrates that the proposed method can effectively restrain the transmission of the jump error and relieve the decline of the parameter estimation precision caused by the drift error,which shows a good performance in range alignment.关键词：ISAR;range alignment;weighted least squares;iterative update2|2|8更新时间：2025-07-16
- 摘要：The main task of access control is to prevent unauthorized accesses to information resources.Conflict detection and resolution mainly solves problems caused by various security policies among different information systems.With the development of computer and communication technology,several access control models have appeared such as discretionary access control,mandatory access control,role based access control,task-based access control,access control for distributed environment and cross-domain,spatiotemporal attribute based access control and security attribute based access control,etc.The paper analyzes and summarizes the existing domestic and international research situation in the field of access control and conflict detection and resolution from the theoretical research and application aspects,indicates exiting problems in ubiquitous networks for the cyber-physical society,and points out some development trends of fine-grained and multi-level security access control model and scalable method for its policy.关键词：access control;conflict detection;present status;development trend3|2|44更新时间：2025-07-16
- 摘要：Pedestrian detection is an active area of research with challenge in computer vision.This study conducts a detailed survey on state-of-the-art pedestrian detection methods from 2005 to 2011,focusing on the two most important problems:feature extraction,the classification and localization.We divided these methods into different categories;pedestrian features are divided into three subcategories:low-level feature,learning-based feature and hybrid feature.On the other hand,classification and localization is also divided into two sub-categories:sliding window and beyond sliding window.According to the taxonomy,the pros and cons of different approaches are discussed.Finally,some experiences of how to construct a robust pedestrian detector are presented and future research trends are proposed.关键词：pedestrian detection;object detection;intelligent surveillance;driver assistance systems15|3|57更新时间：2025-07-16
- 摘要：According to the application of wireless sensor networks in three dimensions,a novel 3D positioning algorithm based on Euclidean for wireless sensor networks is proposed.The problem of the distance calculation between an unknown node and an anchor node is transformed into a solution of the distance between the vertices in Hexahedral.It can be realized by the method of coordinates.The coverage is increased by the way of cyclic iterative method.Simulation results indicate that the performance of the algorithm is good and the algorithm can effectively realize the position of nodes for wireless sensor networks in three dimensions.关键词：wireless sensor network;3D position;Euclidean algorithm4|2|10更新时间：2025-07-16
- 摘要：A distributed medium access control algorithm applied in vehicular ad hoc networks is presented to improve the utilization rate of wireless channel.It includes the construction of a kind of user irrepressibility protocol sequence based on Chinese Remainder Theorem,and the assignment of the protocol sequences to the vehicular nodes which are also called users.The vehicular nodes transmit or receive the packet according to the assigned sequences instead of the coordination by base station or access point.The designed user irrepressibility protocol sequences can guarantee that each vehicular user can successfully transmit a packet within a period.The simulation results show that the transmission delay under the control of protocol sequences mentioned is less than that of slotted ALOHA.关键词：vehicular ad hoc network;protocol sequences;user irrepressibility;slotted ALOHA;transmission delay2|2|2更新时间：2025-07-16
- 摘要：The detection model of Frequency-Hopping(FH) signal based on channelization is studied.After introducing and deriving the traditional detection model,the reason why the complexity of this model is high is analysed and a kind of step-division detection model is presented.By the operation of step-division,the useless bandwidth monitored is reduced,the computation is reduced largely and the utilization efficiency of the resource for the model is increased.After deriving the computation formula of every step-division,a kind of assembly-line model is presented.It can reduce the computation further and enhance the practical value of the model.The simulation results show that the computation of the improved model is reduced largely comparing with the condition model.关键词：Frequency-Hopping(FH) communication;signal detection;channelization2|2|4更新时间：2025-07-16
- 摘要：In the S-P networks,the design of P-transformation is very important,and is related to integral diffusion performance of block cipher.Based on the importance of P transformation,we propose the concept of a class of special bit transformation.We prove that the special bit transformation is involutory transformation and it's branch number is 4.We also give the number of input-output correspondences whose weight sum equals to 4.By further analyzing,it is shown that the special bit transformation has good diffusion performance though it's branch number does not obtain maximum.关键词：a class of special bit transformation;involutory transformation;branch number;diffusion performance2|2|0更新时间：2025-07-16
- 摘要：An improved QIM (Quantization Index Modulation) steganography was proposed and it can be used for efficient information hiding in G.729A compressed speech stream.This paper wants to detect this type of steganography.This paper proves that such steganography will significantly change the imbalance and correlation distribution characteristics of codeword (quantization index) in the stream.And then it designs statistical models to extract the quantitative feature vectors of these characteristics.Combining the extracted vectors with the support vector machine,this paper constructs an ensemble classifier for detecting the QIM-based steganography in the G.729A speech stream.The experimental results show that the classifier can achieve up to 98% correct detection towards G.729A encoded speech stream with detection time less than 30 milliseconds.关键词：information hiding;steganalysis;G.729A;quantization index modulation;codeword distribution characteristics2|2|4更新时间：2025-07-16
- 摘要：Based on a continuous-time state-space structure and the generalized bilinear transformation(GBT),a parameterization for IIR digital filter design is proposed.The cost function can be minimized without stability monitoring because the corresponding stability region is the entire parameter space.Simulation shows that the performance of the filters obtained with the proposed approach is better than that of those designed with an existing one in terms of passband ripple,stopband attenuation and group delay.关键词：infinite impulse response(IIR) digital filter design;state-space realization;GBT;parameterization2|2|6更新时间：2025-07-16
- 摘要：A method of coupling waveguide slot's active impedance calculation is presented due to the complicated electromagnetic field in waveguide and disadvantage in engineering application.The equation contained slot's active impedance is created according to the relation between the S matrix and the input impedance at the port of coupling waveguide.Newton method is applied to solve the higher order fractional equation to obtain the coupling slot's active impedance which takes mutual coupling between slots into account.Computer simulation results obtained by applying S matrix extracted from HFSS software in coupling slot's active impedance formula indicates that the method proposed in this paper is effective and suitable for coupling slot of large waveguide slots array antenna design.关键词：coupling waveguide slot's active impedance;active impedance;S matrix;input impedance2|2|0更新时间：2025-07-16
- 摘要：A novel Hybrid Evolutionary Algorithm based on Quantum computing (HQEA) is proposed.In the algorithm population is divided into subpopulations by niche methods.Each subpopulation can obtain optimal solution by the self-adaptive operator and all subpopulations can co-evolve by quantum dynamic mechanism.Initialization chaotic sequence is not as well as random in homogeneity,so this approach proposes strategy of unsymmetrical area to obtain optimal solution more.This approach adopts real-coded chromosome to solve precision and efficiency problem of binary system.The algorithm can adjust to dynamic environment more because of the distributed and parallel characteristic based on quantum dynamic mechanism.The convergence of the HQEA is proved and the strategy for improving the performance of HQEA has been analyzed.Its superiority is shown by some simulation experiments in this paper.关键词：quantum evolutionary algorithm;quantum dynamic mechanism;coevolutionary;multi-modal function optimization;real-coded chromosome2|2|1更新时间：2025-07-16
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