最新刊期
卷 31 ， 期 10 ， 2003
- 摘要：A novel optical User Network Interface(UNI)signaling protocol for optical network dynamic resource provisioning is proposed for dynamic lightpath provisioning.The protocol supports multi-client addressing and meets the special requirements of optical networks.The protocol has been formally specified and validated,employing a Communicating Finite State Machine (CFSM)model.Exceptional handling of the protocol is analyzed.Validations confirm that the protocol performs lightpath actions correctly under both normal and any time out conditions,with its no-deadlock,no-livelock,and other good properties.关键词：optical networks;UNI;signaling protocol;formal validation and verification4|857|0更新时间：2025-07-16
- 摘要：By analyzing the performance of the IEEE 802.11 DCF(Distributed coordination funclion),this paper discovers that the probability distribution of slot selection of the IEEE 802.11 DCF is obviously not uniform.This gives high packet collision probability.For this reason,this paper provides a simple scheme,named A-DCF.Through simulation of IEEE 802.11 DCF and A-DCF,it proves that A-DCF has more uniform probability distribution of slot selection and lower packet collision probability at almost the same saturation throughput.At the same time,A-DCF is adaptive to the network load.关键词：distributed coordination function;performance;probability distribution of slot selection;collision probability2|1272|4更新时间：2025-07-16
- 摘要：In this paper we first prove the existence of congestion externality in current Internet which leads to inefficient resource usage under a game model.Then we present a universal game theoretical framework to deal with this problem,provide a comprehensive analysis of centralized and decentralized control problems in IntServ,DiffServ,usage-based pricing,which are the most representative schemes proposed in the literature to support multi-service in resource allocation,and give a complete characterization of Nash equilibria and their existence criteria.At last we show under what conditions the solutions are system-optimal.关键词：game theory;congestion control;IntServ;DiffServ;usage-based pricing2|1253|10更新时间：2025-07-16
- 摘要：In this paper we first analyzed the effect of MAI in CDMA mobile communication when using downlink signal to position mobile station,and then proposed an algorithm through mathematical derivation.Using this algorithm we can calculate the reliability of the estimation of Time of Arrive of downlink signal,get rid of the result that is not reliable,and improve the veracity of location estimation.The algorithm is very simple .Simulation results demonstrate that the proposed algorithm can reduce error of location estimation very greatly.关键词：CDMA;downlink pilot signal;MAI;TDoA;ToA2|879|0更新时间：2025-07-16
- 摘要：According to the baseband signal model and features in Code Division Multiple Access(CDMA)communication systems,the paper analyzes SNR estimation techniques for Quadrature Phase-Shift Keying (QPSK)modulations and proposes a novel SIR estimation technique for CDMA.The results of computer simulation show that the estimation creditability using this technique is higher than others in low SIR.关键词：CDMA;SIR;estimation2|1393|1更新时间：2025-07-16
- 摘要：Dual Round-Robin(DRR)algorithm[6] is a crossbar control algorithm that is fair,highly efficient,scalable and easy to implement by hardware.To improve delay performance and fairness about DRR algorithm,we advance DRR to iDRR which can run in iterations and inherits all of advantages of DRR.The results of simulation indicate that iDRR can achieve 100% throughput,furthermore,both delay performance and fairness about iDRR precede that about DRR.We implement arbiter based on iDRR by programmable logic device which can operate at clock frequency of 80MHz.It can support 10Gbps input ports,and can be used in super high speed and large capacity routers.关键词：input queuing;matching algorithm;VOQ;DRR;iDRR2|1319|3更新时间：2025-07-16
- 摘要：Two novel location algorithms with Non-Line-of-Sight(NLOS)propagation considered are introduced.By inserting some loose varables to represent NLOS,an iterative method was introduced to mitigate the influences of NLOS propagation.The other one is,by moving the base stations virtually,to increase the distances between the base stations and the mobile to replace NLOS with Line-of-sight(LOS),then use the maximum-likelihood estimation and iterate until the solution converges.The simulations and comparisons show these two methods are more effective.关键词：wireless location;line-of-sight propagation;non-light-of-sight propagation;maximum-likelihood estimation;TOA2|1036|0更新时间：2025-07-16
- 摘要：In this paper,we propose a new time-domain estimator for OFDM signal by using over-sample processing.The proposed estimator is able to achieve wider estimation range of carrier frequency offset with higher accuracy than cyclic prefix(CP)based estimator.And the results of computer simulation show the proposed estimator overcomes the impact of carrier frequency offset and achieves the same accuracy regardless of the carrier offsets.关键词：OFDM;carrier frequency offset estimation;carrier synchronization2|858|0更新时间：2025-07-16
- 摘要：A new adaptive closed loop robust blind image digital watermarking technique in wavelet domain is proposed.The embedding process is modified according to the results of the performance analysis of watermarking.If the watermark can not meet the requirements or the embedded watermark renders visual artifact,the embedded intensity of watermark is modified so as to obtain the optimal embedding effect.The convergence of the closed loop techniques is proved.The probabilities of false alarm and detection are also given which are used as the performance measures of the closed loop system.The watermark detection process adlopt independent component analysis and do not need any information about original image and original watermark and can extract not merely detect the perfect watermarks embedded.Experimental results show that this adaptive closed loop robust blind watermarking performs better than the traditional adaptive watermarking.The method proposed in this paper has a good robustness to the popular watermark test software-Stirmark.关键词：adaptive closed loop watermarking system;blind detection;independent component analysis2|825|8更新时间：2025-07-16
- 摘要：Two perspective images of single scene taken by uncalibrated perspective cameras are constrained by the epipolar geometry,which is the key to many problems of computer vision.This paper addresses the problem of robust estimating the epipolar geometry employing a new method based on messy genetic algorithm,which use each gene to stand for a pair of correspondences,and take every chromosome as a minimum subset for epipolar geometry estimation.The method would eventually converge to a globally optimal solution and is relatively unaffected by the outliers.Experiments with both synthetic data and real images show that our method is more robust and precise than other typical methods because it can efficiently detect and delete the bad corresponding points,which include both bad locations and false matches.关键词：epipolar geometry;fundamental matrix;messy genetic algorithm(mGA)2|841|3更新时间：2025-07-16
- 摘要：An anomaly intrusion detection method based on a HMM is given.We pass the system call trace of unix privileged process into a HMM to get state transition sequences.Preliminary experiments prove the state transition sequences can express the different mode between normal action and intrusion behavior more stably and more simply than the short sequence in TIDE can do.Although building a HMM is computationally expensive,we can get three advantages,that is,smaller profile database,needing smaller training data,and greater difference between normal data and abnormal data.So we can detect more quickly and with lower false positive rate.关键词：intrusion detection;anomaly detection;HMM;system call;normal profile2|2147|8更新时间：2025-07-16
- 摘要：It is the basis for security of information systems to establish an information system security model.For information systems the security models in existence have showed insufficiency obviously.To adapt the properties of highly opened and distributed network based information systems today,through the definition of security domains,the new model gives study on unique domain system,simple system and complex system respectively.A model adaptable for the security of information systems is presented.Thus a basis for the security of information systems is found theoretically.关键词：security model;security policy;information system security;security domain2|1087|8更新时间：2025-07-16
- 摘要：This paper first proposes a DNA algorithm based on surface for the maximal matching problem.The main idea is to generate the possible solution space step by step in the solid surface,and at the same time these fault solutions are deleted through the digestion process of restriction enzymes.Finally the influence of the edge order on the solution generating process is discussed.Our results show that the solution space can be efficiently reduced by a reasonable arrangement of the order of edges.关键词：DNA computing;surface-based fashion;maximum matching problem2|1143|12更新时间：2025-07-16
- 摘要：Fingerprint identification has been studied widely because it is the most significant biometrics technology and has the potential to be widely adopted in very civilian applications.But so far,the existed fingerprint identification algorithms cannot extract features accurately and are time-consuming.In this paper,a new algorithm which is based on the ridge-sampling is presented.The algorithm overcomes the main shortcomings of the current available algorithms and is simple,fast,effective and robust.关键词：fingerprint identification;pattern matching;fingerprint orientation2|1648|1更新时间：2025-07-16
- 摘要：A self-organizing learning algorithm is proposed to perform invariance extraction and recognition of handwritten digits.In order to built adaptively an optimal network topology in the learning procedure for a given recognition problem so as to avoid overtraining,an adaptive pruning method is proposed.Computer simulation show that the proposed algorithm is effective on extracting invariance of handwritten digits and optimizing a network topological architecture.关键词：pattenr recognition;havdwritten digit;handwritten digit rcognition;feature extraction2|894|0更新时间：2025-07-16
- 摘要：Electrostatic precipitator needs every kinds of important information of whole system,especially system fault information,to run stably.This paper analyzes back corona fault and place-line distance shorten failure by PRONY method,which are two indiscriminative faults of electrostatic precipitator.The research result shows that PRONY method can distinguish these two faults efficiently,which can redeem the inefficiencies of traditional methods.关键词：electrostatic precipitator;fault detection;PRONY2|957|0更新时间：2025-07-16
- 摘要：In order to achieve high compression ratio in coding stereo video sequences,one sequence of stereoscopic sequences is independently coded by a conventional MPEG-type scheme,only a few reference frames in another sequence are coded.The rest of frames,however,are neither coded nor transmitted.They are reconstructed at the decoder using a stereoscopic frame estimation technique.This paper studies the highly spatial and temporal correlation between images,disparity fields and motion vector fields in the neighbor frames of stereoscopic sequences and proposes a frame estimation technique to explore these correlations.As to those un-estimated regions due to occlusion,this paper also constructs a cost function combined with the continuity of image intensity and the distribution characteristic of motion and disparity vector to estimate the motion vectors and intensities of them.The experiment results show that this frame estimation algorithm has good results on view perception and PSNR.关键词：stereoscopic;occlusion;frame estimation2|846|0更新时间：2025-07-16
- 摘要：It is well known that human body can be approximately modeled by articulated object.The anatomical knowledge reveals that there exist multiple constraints on human motion such as rigidity constraint,static rotation constraint,and so on.In this paper,we estimate 3D human motion by rigidity and coplanar constraints.In theory,we analyze the 3D structure of multi-link from motion,and investigate the relationship among the number of the frames and links and the number of equations and unknowns.By Genetic Algorithm,the robust numerical solutions can be achieved.The experiments with the simulated data and the real images are included to demonstrate the validity of the theoretic results.关键词：articulated model;rigidity constraint;coplanar constraint;motion Analysis.3|764|1更新时间：2025-07-16
- 摘要：The problem of concern here is parameter estimation of two-dimensional harmonics in the presence of multiplicative and additive noise.Two-dimensional cyclic statistics which can restrain two-dimensional multiplicative noise and two-dimensional additive noise efficiently are employed to estimate the frequencies and phases.Simulation examples illustrate the algorithm.关键词：two-dimensional;cyclostationary;cyclic statistics;multiplicative noise2|1029|3更新时间：2025-07-16
- 摘要：A differential method for capacity control is presented based on the analysis of the capacity of learning machines.Our method that can be applicable to the set of nonlinear hypothesis functions as well as the set of linear ones generalizes the theory about the capacity control of SVMs.A new learning machine is proposed based on differential capacity control method.In our learning machine,a good generalization performance can be obtained by the right balance struck between the empirical risk and the differential of the set of hypothesis functions that controls the machine capacity.Simulation results show the feasibility of our learning machine.关键词：learning machine;support vector machines;capacity control;pattern recognition;regression estimation2|1099|1更新时间：2025-07-16
- 摘要：In order to strengthen the anti-jamming ability for high-frequency surface wave radar (HFSWR),the paper proposes a uideband receiving antenna arrays for the HESWR based on orthogonal loop/whip antenna to combine modern antenna theory with digital signal processing techniques.The scheme and performance with the software and hardware design are presented too.关键词：high-frequency surface wave radar;adaptive anti-interference;orthogonal loop/whip antenna2|1612|3更新时间：2025-07-16
- 摘要：A range-Doppler clutter power spectrum density (PSD) computation method for pulse Doppler radar is introduced in this paper.For the contradiction between precision and rapidity in clutter-simulation,a novel and real-time computation method is proposed for clutter PSD,with which the data of the area units are pre-stored and then the clutter PSD is reconstructed at real time.High precision and high speed (The time of clutter PSD computation is less than 100ms.) are achieved by applying this method.关键词：pulse Doppler radar;clutter;PSD;range-Doppler2|2238|1更新时间：2025-07-16
- 摘要：The history,research areas and development directions of the artificial immune system are reviewed.The research on immune mechanism,algorithm and application are emphasized. The similarities and differences between the AIS and evolutionary algorithms,neural networks,general optimized algorithm are studied.Based on the disadvantage of AIS,the development directions are discussed.关键词：artificial immune system;evolutionary algorithms;neural networks4|6068|116更新时间：2025-07-16
- 摘要：Rijndael has been selected by NIST to become the Advanced Encryption Standard(AES)and published as FIPS 197 in November 2001.The cryptanalysis of AES is the most attentive problem at present.In this paper,some new developments on cryptanalysis of AES including Integral Cryptanalysis,Power Analysis and Algebraic Attack are introduced and some potential research ways are presented so as to draw our attention.关键词：AES;integral cryptanalysis;power analysis;Algebraic attack2|2272|13更新时间：2025-07-16
- 摘要：This paper mainly compares some different PFQ scheduling algorithms according to their QoS parameters such as end-to-end delay,delay jitter and so on.Two different methods to reduce complexity of these algorithms in hardware implementation are also provided.关键词：packet fair queuing;timestamp;GPS8|1387|0更新时间：2025-07-16
- 摘要：An equal-average equal-norm nearest neighbor codeword search algorithm(EENNS)is presented for vector quantization in this paper.Before encoding,the mean value and norm are first computed for each codeword,and then codewords are ordered according to the ascending order of their mean values.During the encoding process,the algorithm first selects the codeword that has minimum mean distance from the input vector as the tentative matching codeword,and then applies two efficient elimination criteria to search the nearest codeword close to the tentative matching codeword up and down.Experimental result shows that this algorithm is more efficient than the equal-average nearest neighbor search algorithm(ENNS)and recently-presented norm-ordered search algorithm(NOS).关键词：vector quantization;codeword search;fast encoding2|894|6更新时间：2025-07-16
- 摘要：In order to deal with the copyright issues in DVB environment,a MPEG domain watermarking algorithm is proposed here.The watermark is embedded by modulation of corresponding DCT coefficients according to human visual system.The threshold of the detection correlator is dynamically adjusted along the time-axis to fit the frame characteristics.The proposed method is of low complexity and easy to be implemented in terminal consumer electronics devices.It has enough robustness in the copy control and user tracing scenarios.关键词：digital video watermarking;digital watermarking;copyright protection2|843|1更新时间：2025-07-16
- 摘要：An effective method of calculating and eliminating the multiple-access interference (MAI) introduced by the pilot signal in cdma2000 systems is presented in this paper.Its applications to single-cell and multi-cell environments are also described.Computer simulations show that the RAKE receiver with the proposed pilot cancellation scheme can not only ensure the accuracy of channel estimation and combine separable multi-path components but also effectively eliminate the MAI due to the pilot signal.So the system performance is greatly improved.Besides,pilot cancellation at symbol rate leads to relatively low hardware complexity in its implementation for practical systems.关键词：pilot cancellation;RAKE receiver;CDMA20002|658|0更新时间：2025-07-16
- 摘要：This paper presents a novel Hybrid ARQ (Automatic Repeat reQuest) scheme,which jointly utilizes RCPT (Rate Compatible Punctured Turbo) codes and CPC (alternate "Codeword retransmission"and"Parity retransmission" & Chase combining) strategy.Performance of the proposed scheme is investigated by numerous simulations and compared with several current Hybrid ARQ schemes using RCPT codes over Rayleigh fading channel.Numerical results show that the proposed scheme can provide better performance with lower system complexity.关键词：hybrid ARQ;RCPT codes;alternate"codeword retransmission"and"parity retransmission";chase combining4|769|0更新时间：2025-07-16
- 摘要：Blink artifacts and power noise are constantly found:to strongly iufluence the acquisition and analysis of EEG signals.In this paper,by comparing the efficiencies of two ICA algorithms—Infomax-ICA and Extended-Infomax-ICA methods in extracting blink artifacts and power noise in the EEG signals,it was shown that ICA algorithms were insensitive to disturbance in the conditions of low signal-noise-ratio,and ICA algorithms demonstrated a strong robustness in processing non-stationary signals.Though blink slow waves could be extracted by infomax algorithm,but power noise was unlikely to be removed by it.Therefore,Extended-Infomax ICA algorithm should be used.By applying Extended-Infomax algorithms,blink artifacts and power noise contained in the 16-channel EEG signals of Alzheimer-disease patients were removed successfully(the lowest signal-noise-ratio for power noise can be -40dB).Meanwhile,it proved by calculating approximation entropy (ApEn) that ICA algorithms could preserve the nonlinear characteristics of EEG after removing the interference.关键词：EEG;blink artifacts;power noise;independent component analysis;infomax2|2346|11更新时间：2025-07-16
- 摘要：Ultra wideband(UWB)signaling is an important new emergent technology for wideband multiple- access communication system.A theoretical analysis of UWB signals for various modulation methods is presented.Power spectral density for the time-hopping modulated UWB and for a direct sequence phase coded UWB approach are detailed,which can provide important insights into the design and interference performance of UWB communication system in a multiple-access environment.关键词：UWB;multiple access communications;power spectral density2|1302|7更新时间：2025-07-16
- 摘要：The protection of bidder privacy and the prevention of bidder default are the keys in the designing of Secure Electronic Auction Scheme.This paper gives a secure sealed-bid auction scheme using only a one-way function.Our scheme can satisfy all the secure requirements of sealed-bid auction stated and has the advantages similar to the scheme of [1].关键词：sealed auction scheme;one -way function;bidder anonymity;privacy protection2|928|3更新时间：2025-07-16
- 摘要：The performance of wavelet packet modulation based on Quadrature Amplitude Modulation under different channel models is theoretically analyzed in this paper,and we simulate the wavelet packet multi-carrier modulation system,which is compared with OFDM orthogonal freqaency division multiplexing modulation system based on DFT from variant aspects.Finally,the possibility of wavelet packet modulation application in Digital AM transmission system is discussed.关键词：digital AM;wavelet packet transform;multi-carrier modulation;QAM2|964|2更新时间：2025-07-16
- 摘要：The decomposition of the multi-channel filter banks has been discussed.It is known that any discrete wavelet transform or two band subband filtering with finite filters can be decomposed into a finite sequence of simple lifting steps.The proof of this decomposition is provided using an algebraic method.It is also proved that multi-channel filter does not have this decomposition.It proposes using lifting scheme and block factorization of the polyphase matrix to construct 2M-channel FIR filter banks from M-channel FIR filter banks. This method is easy to build non linear filter banks, such as integer-integer transforms.关键词：filter banks;polyphase matrix;factorization;lifting scheme4|791|0更新时间：2025-07-16
- 摘要：For an linear code,it is proved that,if it is r-equiweight for one r with 0＜r＜k,then it is r-equiweight for all 0＜r＜k.关键词：generalized hamming weight;r-equiweight code;maximal projective code.2|1106|0更新时间：2025-07-16
- 摘要：This paper proposes a method for allocating the transmit power on cdma2000-1x forward link channel under the conditions of multi-path and different rate,i.e.,based on the dependency that exists between the respective signal qualities of the pilot channel and traffic channels to allocate the forward link power reasonably.With laboratory test and theory deduction,the paper gives the graphics of their dependency,and then an optimal pilot signal quality is found which minimizes the total transmit power under the condition of 1%FER.关键词：power allocation;code division multiple access(CDMA);system capacity2|858|1更新时间：2025-07-16
- 摘要：This paper brings forward a new DFS algorithm utilized in WLAN/WPAN and gives the disposition processing.As a material application example,the paper simulates the algorithm in HIPERLAN/2.Compared to other algorithm,the result of simulation indicates that the new algorithm has these characteristics such as fast finding interference and steady changing frequency.The algorithm can satesfy request of WLAN/WPAN in complex communications environment and ensure Quality of Service (QoS) of systme.It has been used successfully in the HIPERLAN/2 system developed.关键词：WLAN;WPAN;dynamic frequency selection (DFS);HIPERLAN/2;QoS2|938|2更新时间：2025-07-16
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