最新刊期
卷 35 ， 期 4 ， 2007
- 摘要：Due to historical reasons,the original model of existing information networks is that one network corresponds to one main service,and this mode can’t adapts well to increasing multi-demands of networks and services.In this paper,we study the new information network architecture to address the serious shortcomings of existing information networks.First we give a new framework of Universal Network and Pervasive Services,which includes two layers:Network Communication Layer and Service Layer.Second we propose the basic model and theory of Universal Network,including accessing identifier,switching-routing identifier and mapping mechanism between them.Third we bring forward theory and mechanism of Pervasive Services,including service identifier and its parsing theory,connecting identifier and its parsing theory.In the end,we develop the prototype system and validate responding theories.Results show that our new network architecture overcomes shortcomings of existing information networks in mobility,security and so on.Also,the new network system can support pervasive services perfectly.关键词：new network architecture;universal network;pervasive services2|2395|0更新时间：2025-07-16
- 摘要：The original model of existing information networks is that one network supports one main service.To overcome the serious shortcomings of these networks,it is necessary to establish new network architecture and its basic theoretical systems.In this paper,a novel future network—Universal Network is designed by research on switching and routing theories of various current networks.Firstly the accessing identifier,switching-routing identifier and the mapping scheme between them are introduced,and then general switching-routing theory of the new network is created,the Universal Network model and theory are set up accordingly which solve the universal issues of heterogeneous networks besides security and mobility problems.A scheme is also provided to ensure the smoothing transition from existing networks to the Universal Network.Finally,an implementation of the Universal Network is put forward and the corresponding prototype system is designed.Some experiments have been performed and results show that the Universal Network is feasible,effective and reliable.关键词：switching-routing identifier;identifier mapping;general switching-routing theory;universal network2|720|27更新时间：2025-07-16
- 摘要：Based on the general principle and mechanism of traditional network services,this paper describes the pervasive service model of new universal network.In the new model,service identifier is introduced which is used as the unify description of network services,and based on service identifier this paper designs unified service management mechanism.Connect identifier is the identifier of service connect and terminal identity,which is used to support mobility and safety network services,and based on connect identifier a new transport protocol is designed for real-time network service.The parsing and mapping of service identifier connects virtual service module and virtual connect module and also completes the mapping from service identifier to multi-connect identifiers.The parsing and mapping of connect identifier connects virtual connect module and network communication layer and also completes the mapping from connect identifier to multi-switching identifiers.Prototype system and simulation can prove correctness,effectiveness and feasibility of the new service model.关键词：service identifier;connect identifier;parsing and mapping;pervasive service2|706|18更新时间：2025-07-16
- 摘要：Wireless Mesh Network(WMN) is a new distributed broadband access network.Compared with the typical mobile Ad hoc network,it is with less mobility and usually not powered by the battery.Therefore,the traditional mobile Ad hoc routing protocols are no longer suitable for WMN.In order to meet the performance requirements of multimedia traffic transmission,the routing protocol designed for WMN must be taken into account the combination of load balance,fault tolerant and throughput,etc.This paper firstly introduces typical structures and characteristics of WMN,and several relevant WMN routing protocols.Then a method of integrated metrics based Extended Dynamic Source Routing (EDSR) protocol is proposed.The analysis and simulation results show that the proposed EDSR protocol improves the throughput of WMN significantly,which reaches the target of load balance simultaneously.关键词：wireless mesh networks;routing protocol;cross-layer design;load balance2|1336|7更新时间：2025-07-16
- 摘要：Data consistency must be kept to ensure correct concurrency when there are conflicts between concurrent transactional workflows.Cascading aborts caused by those conflicts will increase execution costs,especially for long running and heavy-priced workflow instances.For complex transactional workflow applications in heterogeneous distributed environment,traditional concurrency control techniques can not reduce cascading aborts when the concurrency correctness is guaranteed.In this paper,we proposed a QoS-based dynamic scheduling algorithm for transactional workflows.Matching requirements of heterogeneous environment,the algorithm allows different recovery policies for scheduled activities.Furthermore,it supports QoS-based deferred-scheduling policy and SAFE-set-enlarging policy.It can adjust scheduling decisions according to the reliability,execution time or price of an activity.It is proved that the proposed algorithm produces serializing and recoverable schedules;moreover,it will not lead to starvation.Performance analysis shows that the algorithm can reduce cascading aborts,thus can provide a high degree of concurrency.关键词：transactional workflow;concurrency control and recovery;scheduling algorithm;QoS;cascading abort2|673|0更新时间：2025-07-16
- 摘要：In orthogonal frequency-division multiple access (OFDMA),closely spaced multiple subcarriers are assigned to different users for parallel signal transmission.An interleaved subcarrier-assignment scheme is preferred because it provides maximum frequency diversity and increases the capacity in frequency-selective fading channels.Carrier-frequency offsets (CFOs) between the transmitter and the receiver destroy the orthogonality and introduce ICI and multiuser interferences.A subspace-based two stages searching algorithm is proposed in this paper for estimating the CFOs of all users simultaneously in the uplink of Interleaved OFDMA systems using only one OFDMA block.Compared with existing CFO-estimation algorithms,it does not need the a priori info,such as the number of users and their occupied subchannels,so it is suitable for the case that subchannels randomly assigned.Simulation results illustrate the high accuracy and efficiency of the proposed algorithm.关键词：orthogonal frequency-division multiple access(OFDMA);carrier frequency offset(CFO);subspace;normalized root mean square error (NRMSE);world interoperability microwave access(WiMAX)2|892|0更新时间：2025-07-16
- 摘要：The completeness and correctness of detection rule set are key points to enhance the real-time detection rate of the feature interaction manager (FIM).Based on the random search capability of the genetic algorithm,an evolution algorithm of detection rule set is proposed.In the algorithm,the known interactions are added and the new services are selected to mutate by the degressive probability,which improve the evolution speed.Optimizing the detection rule set can reduce the time and space complexity.The experiment results show that the algorithm advances the performance of the FIM.关键词：next generation network;feature interaction;detection rule;genetic algorithm;detection rate2|668|2更新时间：2025-07-16
- 摘要：Using cache in the voice platform based on VoiceXML (Voice eXtensible Makeup Language) could reduce the cost of network bandwidth,server-load and delay of request.Through analyzing the cache model of voice platform,the Fitting & Predicting algorithm is proposed.It estimates the validity of the cached document by performing parameter fits to stochastic distribution and predicting the change probability of VoiceXML documents within a certain period.Simulated research indicates the algorithm surpasses the Alex protocol and can obtain a stale ratio lower than 1/10000 to meet the demand of the voice platform while effectively enhancing the system performance.关键词：cache consistency;parameter fits;VoiceXML;exponential distribution;lognormal distribution;Pareto distribution3|663|0更新时间：2025-07-16
- 摘要：A polling-on-demand scheduling algorithm for bluetooth piconet is presented,which has good characters of low delay,high channel utilization and desired fairness.The algorithm computes out estimate of packet arrival rates for upstream links by the rate estimating process,and then it works out the estimate of packet arrival number and latency for every link pair from its last poll time through present moment.According to the dynamic polling selection regulation presented in the paper,the scheduler selects a link pair that has the highest priority to poll,and computes the next polling time according to the adaptive polling interval regulation.The three traffic modes,mixed,downstream and upstream are used to compare the performance between this algorithm and other classical algorithms by simulations.The results indicate that this algorithm has the best integral performance in the first two traffic modes,and particularly,delays decrease by at least 24.1% and 41.4% respectively.The algorithm also has relatively good behaviors in the third traffic mode.This algorithm is efficient and has low complexity,and it can be used for bluetooth and other wireless networks.关键词：bluetooth piconet;scheduling algorithm;polling on demand;delay;channel utilization;fairness2|1098|3更新时间：2025-07-16
- 摘要：An error concealment algorithm based on lagrange interpolation in spatial field and temporal field for H.264 video was presented.Two motion vectors were obtained by interpolating in spatial and temporal field respectively.A hybrid interpolation model was constructed to get the optimal motion vector of lost motion vector by setting up a table for interpolation coefficients and judging with boundary match algorithm.Furthermore,a novel like-interlace method for slices was presented in order to reduce the bad effect of burst error in channel to the interpolation.Simulation results show that this scheme can highly improve the quality of reconstructed video and obtain a gain of about 0.5dB~1dB in PSNR,compared with lagrange interpolation in spatial field in the condition of packet loss rate with 15%.关键词：Lagrange interpolation;interpolation in two fields;motion vector;like-interlace2|1085|2更新时间：2025-07-16
- 摘要：Signature of knowledge is that signer can prove that he knows knowledge of a secret with respect to public information noninteractively and he don’t leak any secret message.Signature of knowledge has been used in many group signature schemes.In this paper,we mainly study on signature functions of knowledge with coefficient,and give out definition and proof of several kinds of signatures of knowledge of discrete logarithm with coefficient.The coefficient can increase the choices of signature functions,make signatures of knowledge more available.关键词：signatures of knowledge;group signature;signatures of knowledge of discrete logarithm with coefficient2|773|0更新时间：2025-07-16
- 摘要：Unlike other already existed iris recognition algorithms,a new efficient algorithm for iris recognition is proposed.In this approach,a bank of multi-scale and multi-orientation odd symmetric Gabor filters are used to capture local frequency information and local orientation information of the iris so as to produce discriminating features.This Algorithm can represent the feature spatial patterns of the iris more comprehensively and avoid the disadvantage caused by only capturing local frequency features or local orientation features.The method of iris matching is similar to a method computing the adopted city block distance,moreover according to the eyelid and eyelash’s distribution,a matching template is used to reduce their disturbance to minimum.Compared with the Daugman’s method,extensive experimental results demonstrate that the proposed method has an encouraging recognition performance.关键词：iris recognition;2-D Gabor filter;local frequency feature;local orientation feature2|1856|5更新时间：2025-07-16
- 摘要：Intra prediction applied in H.264/AVC improve compression efficiency greatly of I frame.But the full search algorithm is computationally expensive and there exist conflict with some real time application and embedded systems just holding limited calculation resource.In order to promote prediction speed,a fast intra prediction algorithm is proposed which select appropriate coding block size based on complexity of the image,use annular slide window to select prediction mode dynamically and define a simple block match regulation.Experiments prove it is so practical and valid that the match speed has been doubled while the quality of reconstruct picture is nearly not decrease.关键词：video coding;intra prediction;block size;annular slide window;block match regulation2|739|3更新时间：2025-07-16
- 摘要：Current statistical audio watermarking can’t guarantee imperceptibility.The proposed scheme in this paper uses a statistical method to embed watermark in the tonal components in wavelet packet domain and integrates psychoacoustic analysis to control watermark strength,which makes watermark inaudible.Error detection rate analysis and experimental results show that the proposed method is inaudible and sustainable against common signal processing manipulations and malicious attacks.关键词：digital audio watermarking;psychoacoustic model;wavelet packet decomposition2|1243|9更新时间：2025-07-16
- 摘要：Generalized self-shrinking sequences are a novel class of stream ciphers.Run-lengths is an important criterion to measure the pseudorandom property of sequences.A good pseudorandom sequence should have short run-lengths.In this paper,by using some pseudorandom properties of m sequences,we obtain a new result about family of the generalized self-shrinking sequences.It is that the run-lengths of each sequence in the sequences family,with the exception of two sequences(000… and 111…),are no greater than n*n-2.5n+3,and no greater than n*n/2-1.25n+3 if n is even.关键词：m-sequence;run-length;self-shrinking generator;shrinking generator;stream cipher2|769|1更新时间：2025-07-16
- 摘要：At present,research on secure multi-party computation is of great interest in the field of information security.Privacy-preserving intersect-determination of two polygons is a special secure multi-party computation problem,it can be applied in many fields,such as military field and commerce field.Scalar products protocol plays an important role in the known methods of privacy-preserving intersect-determination of two polygons,however,the current scalar products protocols aren't fit for the determination algorithm on the security and the complexity at the same time.In this paper,a protocol for privacy-preserving intersect-determination of two line segments is developed and a probability algorithm for privacy-preserving intersect-determination of two polygons is presented.Both of the theoretical analysis and the experiment results show that the new algorithms are more efficient than the current algorithm.关键词：secure multi-party computation;computational geometry;scalar product protocol;algorithm2|1629|15更新时间：2025-07-16
- 摘要：A linear iterative method for projective reconstruction based on 1D subspace is presented in the paper.It relies on the facts that the rows in the matrix including all the image points span the same linear subspace as the rows in the matrix including space points and that the basis of the subspace can consist of the three rows in the matrix comprising the first image points and a row vector which is orthogonal the former.The row vector and the depth factors are obtained based on linear iteration,and lastly the projective reconstruction is accomplished.The experiments with both simulate and real data show that the method is efficient,robust and has good property of convergence and small re-projection errors.关键词：projective reconstruction;factorization method;linear iteration2|989|6更新时间：2025-07-16
- 摘要：Based on H.264,this paper proposes a novel fast selecting inter prediction mode algorithm by using temporal/spatial correlation of video sequence.Two key parameters by which inter prediction mode is determined is adaptive updated.Simulation results show that inter macroblock encoding is obviously speeded up by using above methods.Furthermore,these algorithms are compatible with H.264 standard,and can be used in practice.关键词：video communication;H.264;prediction mode;temporal/spatial correlation2|596|6更新时间：2025-07-16
- 摘要：The adaptive Chirplet decomposition contains a lot of unknown parameters and has much difficulty in its implementation.In this condition,a fast implementation of adaptive Chirplet decomposition is presented in this paper.By computing the quadratic phase (QP) function of the signal,it is shown that the QP function is concentrated along the frequency rate curve of the signal,and the peak of the QP function yields the estimates of the Chirplet rate,time center and the amplitude;Then the initial frequency and the time extent can be obtained by the dechirp technique.The scheme of the algorithm is shown in this paper,and the results of simulated data and echolocation signal from brown bat demonstrate the validity of the method proposed.关键词：adaptive Chirplet decomposition;quadratic phase function;frequency rate curve2|929|2更新时间：2025-07-16
- 摘要：Aiming at three basic services,abnormal event alarm,information query and stream query service,the paper abstracts a QoS routing model for the multimedia sensor networks.Moreover,based on the traditional ant-based algorithm,we propose an ant-colony optimization based service aware routing (ASAR).The ASAR chooses the suitable paths to satisfy with the diverse QoS requirements from different kinds of service,thus maximizes network utilization and improves network performance.Finally,extensive simulation using NS2 is conducted to verify the effectiveness of our solution.Compared to the traditional ant-based algorithm,our ASAR algorithm has better convergence and significantly provides better QoS for multiple types of services in the multimedia sensor networks.关键词：multimedia sensor networks;ant-colony optimization;QoS routing;service aware2|1354|8更新时间：2025-07-16
- 摘要：Spatial diversity is an effective method to resist fading effect in wireless channel.Due to the limitation of size,weight and cost,it is difficult to use the multi-antenna technique on the terminal of wireless communication.Cooperative communication allows the mobile terminals with a single-antenna to share their antennas.Thus virtual multi-antenna can be created to realize transmitting diversity.LDPC code is a good linear block code.Because of the intrinsic coherence among the bits of the code word,we can create virtual multi-antenna and obtain diversity gain by making different users transmit different parts of the code word.Once diversity gain is obtained,the system performance can be improved effectively,without much rise in the system bandwidth and transmitting power,nor would the cost and complexity of the system increase evidently.关键词：fading;cooperative communication;diversity;multi-antenna;low-density parity-check code(LDPCC);coded cooperation2|782|10更新时间：2025-07-16
- 摘要：It is proposed that the essence of fixed network operator transformation is shifting their work emphasis from telecommunication network operation to providing user-centered comprehensive information services.The scope of service is expanded from current network access to informatin convergence integration.Based on network transformation,new price mechanism of information service will be built,and the industrial value chain will be remolded finally.The concept of telecommunication information supermarket is proposed,and its whole design is given subsequently.A brandnew commercial model of the supermarket broadband platform and its establishment are described,and the trend of broadband personality is introduced finally.The emergence of telecommunication information supermarket can lead to a new business model,stimulate consumer demand increasing,make CP(content provider) market prosperous and gain a dominant position in industrial value chain.Results show that this whole design of telecommunication information supermarket is correct,and it has great significance and important reference value to enterprise transform.关键词：telecommunication enterprise transform;comprehensive information services;information supermarket;broadband2|1125|0更新时间：2025-07-16
- 摘要：This paper discussed the complexity of softswitch because of its multi-protocol property.How to deal with the protocol relationships in each protocol group or between different protocol groups was studied.Generic PDU was designed.The extensibility and availability of softswitch were also under consideration.Based on a mechanism of SIP-T,the information translation mode and information encapsulation mode coexisted widely in the generic PDU,by which the high efficiency of system and integrality of information were ensured.The necessity and validity of protocol relationship and protocol grouping were proved.UML was used to design the softswitch.关键词：softswitch;protocol relationship;protocol grouping;generic protocol2|682|0更新时间：2025-07-16
- 摘要：Packet delay in radio link protocol layer is the critical part of session setup delay.Previous study assumed saturation to calculate this delay.But the saturation assumption does not hold for session setup.This paper analyzes the RLP packet delay in session setup.Through the study of the transmission status of all frames in the same packet,we propose an iterative calculation method.Simulation results demonstrate that the proposed method can accurately calculate the packet delay in session setup.Comparing the packet delay under the saturation assumption with the packet delay under session setup,we can find that the former delay can be 100 ms longer than the later one.关键词：wireless data communications;radio link protocol;session setup;packet delay2|855|0更新时间：2025-07-16
- 摘要：In comparison with the multiplex training scheme,superimposed pilot has the advantage of efficient bandwidth and high information rate,thus become more and more attractive.In this paper,the closed form expression of MSE and receive SINR as a function of pilot parameter is deduced,based on the first-order statistic channel estimation algorithm;then an optimal design scheme of superimposed pilot for MIMO systems is proposed to achieve the optimized MSE,receive SINR and PAPR simultaneously;at last the relationship of MSE,receive SNR and pilot parameters is analyzed through simulation,which further validate of optimization scheme.关键词：superimposed pilot;first order statistic;PAPR(peak to average power ratio)2|1244|1更新时间：2025-07-16
- 摘要：In CSFQ,when there exist adaptive flows there will be error between the measurement value of throughput and its real value,furthermore the fairness is seriously degraded.To resolve the problem,the paper mainly studies that how to improve the accuracy of the computation of α value,and proposes a queue length embedded core-stateless fair queue algorithm (QL-CSFQ).In QL-CSFQ,the queue length is concerned to improve the accuracy of the computation of α value.The paper compares QL-CSFQ to CSFQ in fairness,utilization of bandwidth,the queue length and its jitter using large amount of simulations,and the results show that QL-CSFQ can decrease the impact of measurement error on the fairness.关键词：active queue management;congestion control;core-stateless;fairness;queue length2|630|1更新时间：2025-07-16
- 摘要：A method for establishing network protocol model in OPNET based on its ESTELLE description is proposed.The process tree structure in OPNET was used to realize the embedded modules structure in ESTELLE,and the EFSM in ESTELLE were modeled by process modeling mechanism in OPNET.As an example,the course of building MIL-STD 188-220C protocol simulation model with this method was introduced.关键词：protocol modeling;specification description;FSM3|674|1更新时间：2025-07-16
- 摘要：A modification on Mahalanobis distance on samples of limited size by compensation for errors of non-dominant eigenvalues and asymmetrical distribution on dominant principle components is proposed.By the introduction of modified Mahalanobis distance,one can compute efficiently the nearest neighbor in transformed space,with compensation for errors of non-dominant eigenvalues and more accurate characterization of the projection distribution of feature vector on every dominant principal component.Experimental results on UCI dataset for handwritten digit recognition indicate that modified algorithm is effective to improve the recognition performance.关键词：eigenvalue;asymmetrical distribution;Mahalanobis distance;error2|1001|1更新时间：2025-07-16
- 摘要：Otsu’s method is a frequently used thresholding segmentation method.In this paper,in order to utilize the information of edge region,we present a curve thresholding segmentation method based on two-dimensional Otsu’s method.The traditional two-dimensional Otsu’s method can be regarded as a special case of it.Experimental results show that for images with noise the proposed method can obtain better segmentation effect than the traditional two-dimensional Otsu’s method.In order to decrease the amount of computation and promote the speed of segmentation,a recursive algorithm and a wavelet transfer combining with the recursive algorithm are shown.The recursive algorithm only need search the main-diagonal and one sub-diagonal of the two dimensional histogram.Compared with the recursive algorithm of traditional two-dimensional Otsu’s method,the searching space is obviously decreased from searching L×L points to 2L-1 points.关键词：image segmentation;threshold selection;Otsu’s method2|3290|80更新时间：2025-07-16
- 摘要：MPEG-4 is a new ISO standard for video coding.However,its rate-control scheme,Q2,would results in the video quality fluctuation at the low-bit and low-delay video communication.The bit-allocation algorithm of Q2 is analyzed,and its disadvantages are presented.Based on Least Square Support Vector Machine (LS-SVM),a novel bit-allocation algorithm is proposed to improve the bit-allocation accuracy.Subsequently,the proposed algorithm is used to improve Q2.Compared with Q2,the improved Q2 significantly decreases the video quality fluctuation,and improves the picture visual quality.Experimental results verify the proposed bit-allocation algorithm.关键词：MPEG-4;rate control;least square support vector machine;target bit allocation2|499|1更新时间：2025-07-16
- 摘要：MPEG-4 FGS is a fine-grain scalable coding method for MPEG-4.The 8*8 frame interlaced bit-plane coding structure used by the MPEG-4 FGS coding does not support intra-frame dynamic bit rate allocation,and therefore is incapable of supporting content-based streaming transport.Regarding the limitation of the MPEG-4 FGS coding,we propose an intra-frame fine-granular scalable coding method (A-FGS) based on the MPEG-7 content description standard to achieve the goal of real-time intra-frame streaming coding.An optimal bit rate allocation algorithm is also provided for the A-FGS coding method.By using the characteristic of having few non-zero coefficient in the intra-frame 8*8 macro-block high bit-plane,we apply a dynamic bit rate allocation method to improve the coding efficiency in mid bit rate range by about 0.5dB.关键词：fine granularity scalable;scalable coding;rate allocation2|804|0更新时间：2025-07-16
- 摘要：The reconstruction of PROPELLER MRI data is a typical reconstruction of non-Cartesian data.The sampling density compensation in the current gridding reconstruction is accomplished through the convolution of non-Cartesian data,which requires calculating a large number of distances between each other non-Cartesian positions when the number of data is large such as PROPELLER.Therefore the density compensation is highly computationally intensive.In this paper,a new algorithm was proposed for density estimation based on gridding a unity data vector.Since no more computations of distances were needed,the time complexity of the algorithm was decreased greatly.In the experiments,the proposed algorithm is shown to be able to perform the density compensation much more rapidly than the traditional algorithm while achieving equivalent quality of reconstruction.关键词：MRI(Magnetic Resonance Imaging);PROPELLER;gridding reconstruction;density compensation2|664|3更新时间：2025-07-16
- 摘要：In Grid,it is an important strategy that using multicast to realize the large-scale information resource sharing.However,it is very difficult to ensure the security of multicast.In this paper,based on the basic principles of the centralized key distributed strategy and the distributed key distribution strategy,according to the multicast mechanism in Grid,considering the dynamic factors of multicast members,we present the member hierarchy method for key distribution,the member discovery protocol,the clustering protocol and the key distribution strategy,thus constituting the key distribution strategy of security multicast in Grid.In order to validate the feasibility and the availability of this strategy,a simulation experiment is done.The results show that it is feasible and efficient to ensure the security multicast in Grid.关键词：multicast;member hierarchy method;member discovery protocol;clustering protocol;key distribution2|665|0更新时间：2025-07-16
- 摘要：This paper analyzes the security of a group signature scheme based on Chinese Remainder Theorem proposed by Chen-ZW recently.The security of Chen-ZW's scheme relies on the assumption of integer factorization,but it is computable to factor the large integer in the scheme because all the group members share a same RSA modulus n.Therefore,the security assumption is unsuitable for the scheme,and the advantage of the scheme is virtually nonexistent.The paper also gives a modified scheme,which elaborately eliminates the defect of the original scheme and improves the efficiency of the protocol.关键词：group signature;revocation;Chinese remainder theorem;integer factorization3|617|10更新时间：2025-07-16
- 摘要：With the spectra of digital modulated signal and its non-linear transform being analyzed,two new modulation feature parameters are proposed and descriptions of another two features are modified.Then a novel identification scheme is obtained,capable of blind identification of many commonly used digital modulations in AWGN,using a neural-network-ensemble-classifier.The proposed spectrum-shape parameter is anti-noise,while the new spectrum-line one is robust against modulation parameters,and the performance of neural network ensemble is much better than that of a single network classifier.Simulation results show that the recognition rate can reach 94% when SNR is above 5dB.关键词：modulation identification;spectrum feature;fusion;neural network ensemble2|2286|12更新时间：2025-07-16
- 摘要：Dither modulation with distortion compensation is a quantization watermarking algorithm that can achieve high capacity,and it uses the quantization error as the compensation to improve the performances of dither modulation,while the compensation factor is one of the key factors that affect its performances.This paper establishes a common model measuring the robustness of the algorithm from the principle of the minimum distance decoder in quantization watermarking algorithms.Then,this paper uses rate distortion theory to model the lossy compression channel,and obtains the method that can get the minimum bit error rate under lossy compression.The theoretical result shows that the larger the compression strength is,the smaller the compensation factor should be.The experimental result confirms the validity of the theoretical result.关键词：digital watermarking;quantization;compensation factor;lossy compression;bit error probability2|1182|5更新时间：2025-07-16
- 摘要：To detect DDoS attack accurately and in time,the performance of real-time method based on VTP was evaluated,and the effectiveness of this method is proved.Using this method to calculate the Hurst parameter of traffic data set of Lincoln Lab of MIT,the law of change of Hurst parameter during DDoS attack is found—it is that the Hurst parameter increases faster at the beginning of an attack and then it decreases slowly;while the traffic is all DDoS attack traffic,the Hurst parameter descends absolutely (from 0.95 to 0.45).So a technology of detecting DDoS attack on real-time is proposed.关键词：network security;DDoS;real-time detection;Hurst parameter;VTP(Variance-Time Plots)2|919|7更新时间：2025-07-16
- 摘要：A method for controlling chaos by improvement of correlativity is presented.The chaotic dynamic system can be controlled to its equilibrium point and periodic orbits by improving correlativity of a chaotic signal.Mathematical theory analysis is given and computer simulation results are provided to support such controllability of the coupled map lattice system.关键词：chaotic control;correlation integral;the coupled map lattice;spatio-temporal chaos2|956|0更新时间：2025-07-16
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