最新刊期
卷 35 ， 期 1 ， 2007
- 摘要：Based on the principle of trigonometric approximation and non-liner approach,a new QDDFS Architecture with high compression ratio is presented.Its design principle has been analyzed theoretically and all the parameters have also been optimized in Matlab.A high compression ratio of 655.36 is achieved at 96 dBc in a 16bit system.Finally the whole architecture for proposed scheme is given.关键词：direct digital frequency synthesizer(DDFS);trigonometric approximation;non-linear approach2|897|1更新时间：2025-07-16
- 摘要：Based on the property of bandlimited wavelet,a matching method is developed for constructing a new bandlimited scaling function,which has the similar frequency spectrum as the original signal in the band occurring main energy.The scaling filter is an optimizing filter,which locks the frequency band in that energy is concentrated,so that the filter output of the interested frequency components increases.The original signal can be processed with optimize wavelet in real time.The experimental results with electroencephalogram signals demonstrate the method is effective.关键词：self-Adapted wavelet;matching construction;signal processing2|737|1更新时间：2025-07-16
- 摘要：The traditional training methods of Gaussian Mixture Model (GMM) are sensitive to the initial model parameters,and they often lead to a sub-optimal model in practice.To resolve this problem,it proposed a new GMM optimization method.It utilized the niche techniques and Maximum Likelihood(ML) algorithm in the Genetic Algorithms(GA) training step and provided a new architecture of hybrid algorithm.The new hybrid algorithm can reduce the possibility of premature convergence presence and improve the exploitation capabilities of GA.It also used an adaptive updating strategy to control the GA mixture crossover rate and mutation rate.Besides,the other speakers’ discriminative information was integrated into fitness function to increase the accuracy of classification and make GMM more generalization ability.The experimental results show that this method can obtain more optimum GMM parameters and better results than the traditional and the two improved versions for speaker recognition.关键词：speaker recognition;niche techniques;genetic algorithms;adaptive strategy;Gaussian mixture model(GMM)2|827|3更新时间：2025-07-16
- 摘要：In this paper,the research focuses on pitch detection techniques of the low-rate WI speech coding.As the pitch doubling and halving problems of pitch detection often occurred with varied noises and Signal to Noise Ratio (SNR),voice activity detection (VAD) algorithm based on DCT band-partitioning spectral entropy is employed in pre-processing to separate speech and non-speech segments.In order to provide an accurate-pitch-cycle speech for pith detection algorithm,an improved speech decomposition algorithm in DCT domain based on the Harmonic-Noise Model is presented.Then,using the same characteristic of maximum peaks of MCAMDF and NCCF and two pro-processing techniques mentioned above,a pitch detection algorithm in a combination both of two functions together named MCAMDF-NCCF is proposed.In order to satisfy the needs of the pitch accuracy of WI coder and synthesize phase track correctly,a super resolution pitch detection algorithm named MCAMDF-NCCF-FRAC based on MCAMDF-NCCF is also given to get fractional pitch.We applied these algorithms to WI coder,the results from the subjective A/B listening test indicated that both of these two algorithms have a great performance and heavily reduce pitch doubling and halving and voiced-unvoiced error in low SNR,the quality of the synthesized speech satisfies the accuracy of the pitch detection techniques of WI coder completely.关键词：speech coding;pitch detection;voice activity detection;signal decomposition;waveform interpolation2|1685|4更新时间：2025-07-16
- 摘要：There presents a detection algorithm based on spectral mixing model reconstructed from measurement in this paper in order to detect unknown targets in unknown environment.Firstly,we project the hyperapectral imagery to suppress the background interference in order to search target spectral more accurately.Then,we estimate the spectral subspace and construct a spectral mixing model reconstructed from measurements.And based on the proposed spectral mixing modeling,we project the hyperspectral imagery,which suppress spectral signatures of background and improve the SNR,in order to increase the detection power.Finally,the Signal to Local Clutter RMSE (SLCR) and Peak Signal to Local Clutter Mean Ratio(PSLCMR),which is proposed,are used to evaluate the detection.Theoretic analysis and the results of experiment on visible/near-infrared hyperspectral imagery verify the effectiveness of the algorithm.关键词：hyperspectral imagery;Target Detection;reconstructing from measurement;spectral mixing model2|1157|9更新时间：2025-07-16
- 摘要：We employ hypercomplex to describe a color image directly so that all information of the color image can be modeled.Based on hypercomplex singular value decomposition also called quaternion singular value decomposition (QSVD),we present a novel color image quality measure that can be used as a graphical or a scalar measure to predict the distortion introduced by a wide range of noise sources.It reliably measures the distortion not only within a distortion type at different distortion levels,but also across different distortion types.We compare its performance with MSE,PSNR and MSSIM,the test results show that QSVD performs better.关键词：image quality measure;image distortion;quaternion;hypercomplex;QSVD2|1234|10更新时间：2025-07-16
- 摘要：Big blocks or blocks relation techniques are applied in several image authentication schemes to improve security at the cost of localization accuracy is decreased.In this paper,an image authentication scheme based on fragile watermarking is proposed by means of the analysis of all kinds of attacks.On the basis of small blocks,the strong cryptography algorithm is applied,the watermarking is generated by SHA512 and one-way function based on knapsack problem,and is embedded via sliding window and hierarchical structure.The approach can not only resists all kinds of attacks such as vector quantization(VQ),but also localize a tamper to a 2×2 block pixels.Theory analysis and experimental results demonstrate that the proposed scheme improves the accuracy of tamper localization as well as ensure the security.关键词：fragile watermarking;hierarchical structure;tamper detection;tamper localization2|1570|21更新时间：2025-07-16
- 摘要：Finite Ridgelet Transform (FRIT) is a widely used orthogonal transform for its good property of effectively representation of linear singularities in image.But the limitation of "wrap around" effect restricts its applications in image denoising and compression.In this paper,based on analysis of the relation between "wrap around" effect and distribution of FRAT (Finite Radon Transform) coefficients,we proposed an angle-based orthogonal FRIT scheme (AFRIT) which can concentrate the coefficients energy and reduce the influence of "wrap around" more greatly than the usual ones.We then modeled the denoising problem and proposed a novel threshold selecting method based on AFRIT.Experiments carried out on different images with varying levels of addictive white Gaussian noise show AFRIT’s validity.关键词：orthogonal transform;finite ridgelet transform;image denoising;threshold2|699|1更新时间：2025-07-16
- 摘要：Optical Imaging(OI) is a functional imaging technique based on intrinsic signals which contain abundant physiological sources.In this paper,we tried to separate artery from vena based on spectrum features of the heartbeat and respiration oscillations.Vessel network was firstly extracted from a frame of cortical image by threshold segmentation and region growing method,then we computed the spectral powers of heartbeat and respiration signals separately according to an oscillation-related physiological feature that arterial oscillation distributes between 5 Hz and 6 Hz and venous oscillation distributes between 1 Hz and 2 Hz.Separation of artery and vena was successfully achieved by utilizing the spectral power-percentage of heartbeat and respiration signals.The potential value of 0.1Hz oscillation in artery and vena separation was discussed at last.关键词：optical imaging;artery and vena separation;region growing;vessel segmentation2|1309|0更新时间：2025-07-16
- 摘要：This paper proposes a new pattern model of electronic cell (E-Cell) to simulate gene expression,Analog-Cell,provides major algorithms to implement the design and shows the simulative results of the model.Compared with other E-Cell models,the characteristic of Analog-Cell lies in having abundant picture information and simulating the gene mutation on the molecule level.关键词：bioinformatics;electronic cell(E-Cell);artificial life2|1830|8更新时间：2025-07-16
- 摘要：To the problems of threat to routing security and limited energy of the nodes in sensor network,this paper presents a secure routing algorithm based on energy optimization (EOSR).The algorithms takes energy optimization,improvements of secure routing,and shorten of transmission delay as its design targets.With the multi-pile policy nodes with more energy storages will undertake more tasks of data switching,which can obtain optimal routing and prolong network lifetime.Security of routing is also efficiently improved through pre-distribution of public and private key pair.Detailed process of routing finding,routing choosing and routing deleting are given in this paper.The affectivity of this algorithm is proved with emulative experiment.关键词：Wireless sensor networks;network security;routing algorithm;energy optimization;multi-pile policy2|1496|8更新时间：2025-07-16
- 摘要：A new quorum generation algorithm has been presented.A symmetric quorum can be generated based on this algorithm.And the size of the quorum is about 2*sqrt(N).In the basis on the message of transfer,the synchronization delay time of the distributed exclusion has been reduced to T.Through the quorum re-constructing,the sites fault-tolerance of Maekawa type distributed mutual exclusion algorithm has been increased to N-1.The message number exchanged of the CS execution will be reduced to 2m-3m,our distributed mutual exclusion algorithm in this paper has reduced the message complexity of Maekawa type distributed mutual exclusion algorithm m messages,m is the quorum size.关键词：relaxed cyclic difference set;distributed;mutual exclusion;algorithm2|931|8更新时间：2025-07-16
- 摘要：A generalized group-oriented threshold signcryption scheme based on elliptic curve cryptosystem and Schnorr’s signature schemes is proposed in this paper.This scheme simultaneously fulfills the (t,n) threshold signcryption and the (k,l) threshold shared verification,and it has improved the drawbacks of Wang et al.’s scheme and Hsu et al.’s scheme.Our scheme provides both confidentiality and authenticity for group communication with lower communication cost and more efficient computation.Without divulging recipient’s private key and the message m,non-repudiation of sender is provided by means of public verifiability in our scheme.In addition,our scheme can achieve semantic security by preventing the message guess attack.关键词：threshold signcryption;shared verification;group communication;elliptic curve cryptosystem2|1040|8更新时间：2025-07-16
- 摘要：Accurate measurement of network bandwidth is crucial for many Internet applications and protocols.Based on the analysis of IGI algorithm used to measure network available bandwidth,an improved measurement algorithm has been proposed.The experiment results show that the improved algorithm outperforms the current IGI in the evaluation precision and tracing capability.On the other hand,an improved PTR algorithms has been introduced to make the measurement value more stable and more accurate,especially when the bottleneck link on the network path is under high utilization,without making the measurement time added too much and bringing two much network overload into the measured network path.关键词：network available bandwidth;packet pair;active probing;probing gap model(PGM)2|1786|6更新时间：2025-07-16
- 摘要：This paper proposes a link-based optimized shared-protection algorithm for multicast (LB-OSPM) sessions against single link failure in WDM networks.LB-OSPM allows different protection paths of a working tree to share reserved wavelengths.By introducing wavelength usage matrix and wavelength reservation matrix to record the detailed usage of past reserved wavelengths,LB-OSPM also enables the sharing of reserved wavelengths between protection links belonging to different multicast sessions if these links are not going to act simultaneously.Study uses the topology of European Optical Network (EON) to calculate the network blocking probability of LB-OSPM under various conditions of wavelength resources and network loads.The results demonstrate that LB-OSPM lowers network blocking probability by means of a sharing mechanism.Meanwhile,it assures a 100% restorability rate in the case of single link failure.关键词：wavelength division multiplexing(WDM);multicast;shared protection4|570|0更新时间：2025-07-16
- 摘要：A new perfect signal based on perfect punctured binary pairs is presented,which is quasiperfect punctured binary array pairs.The sizes and the transform features of quasiperfect punctured binary array pairs were discussed.By analyzing its Fourier spectrum and studying its existing necessary conditions,we got some theory basis for searching quasiperfect punctured binary array pairs with computer.Some quasiperfect punctured binary array pairs with small size are listed by computer reaching.关键词：information theory;array pairs;quasi2perfect;signal theory2|930|7更新时间：2025-07-16
- 摘要：Vision-based human motion analysis is currently one of the most active research fields,and the human motion recognition is a challenging research topic in this field.Human motion recognition has many promising applications such as intelligent surveillance,perceptual interface and content-based video retrieval.In this paper,the improvements of this topic in the last several years are discussed in detail from three aspects:the category of human motions,motion representation methods and motion recognition methods.At the end of the survey,some vital problems of human motion recognition are presented and analyzed.关键词：computer vision;intelligent surveillance;motion representation;motion recognition3|4275|37更新时间：2025-07-16
- 摘要：There have been various reliable multicast protocols now,but they can’t satisfy special real-time requirement in applications,that is,before new data reach continuously in a certain time step the old data must be recovered,otherwise,the old data are invalidated.A real time reliable multicast protocol is put forward for the special application requirement.It takes techniques of hybrid FEC,hierarchical network local recovery and an active NAK mechanism to control and reduce the recovery time effectively,and use NAK suppression mechanism to preserve its high scalability.For evaluating the performance of the protocol,the processing and recovery procedure delays in the node and end-system are quantitated accurately through the Passion theory on the basis of modeling the protocol communication in this paper.Then the transport delay calculating formula is presented.The simulated results show the transport delay of the protocol has good robustness and scalability.关键词：internet;reliable multicast;active NAK;local recovery;transport delay2|1195|1更新时间：2025-07-16
- 摘要：According to the theory of cyclostationary,symbol rate of some digital modulated signals,whose symbol rate gives out basic cyclic frequency,can be retrieved by estimating cyclic frequencies of signal's nonlinear transform such as cyclic autocorrelation.Nonlinear transform of signal will generate symbol-rate sinusoidal wave and its harmonics as well as continuous colored background self-noise,which distribute mainly within low frequency band and can disturb the identification of spectral lines especially when available data is not enough.This paper delves into the frequency characteristic of nonlinear transform and proposes a novel nonlinear filtering algorithm,which can be utilized to suppress continuous colored background self-noise,based on an obvious fact that symbol-rate spectral line will stand out within its nearby frequency domain,a key advantage that will never belong to continuous self-noise.All-sided Monte Carlo simulations have been carried out to justify this algorithm.关键词：electronic countermeasure;statistical signal processing;cyclostationary signals;symbol rate estimation;nonlinear filtering2|1066|14更新时间：2025-07-16
- 摘要：Beamlet transform is an efficient tool presented by Donoho for multiscale analysis.A fast algorithm for discrete beamlet transform was proposed which reduced the complexity for computing the pixel coordinates on beamlets.This paper improved the complexity-penalized energy based multiscale linear features extraction method.It established the two-scale relationship of the maximal beamlet energy in the dyadic square,and presented a threshold-processed maximal beamlet energy algorithm which could avoid the problem of selecting penalty factor.Experimental results prove the efficiency of the method proposed.关键词：beamlet transform;multiscale;linear feature4|631|8更新时间：2025-07-16
- 摘要：In this paper we analysis the performance of Rife algorithm and point out when the true frequency is much close to quantized frequency of DFT (discrete Fourier transform) Newton’s iteration will be disconvergent because of decreasing of Rife algorithm’s precision.In order to solve the problem we present a modified Rife (MRife) algorithm by moving the signal frequency to the midpoint of two neighboring discrete frequencies and then estimate the frequency using the Rife algorithm.The simulation results show that the performance of MRife does not fluctuate with the distribution of signal frequency.The RMSE (root mean square error) of one iteration of Newton’s method whose initialization is MRife is close to CRLB (Cramer-Rao Lower Bound) throughout the frequency band and the performance is steady.关键词：frequency estimation;iteration;maximum likelihood;Cramer-Rao Lower Bound(CRLB)2|1982|40更新时间：2025-07-16
- 摘要：It is well known that the successful applications of the Kalman filter are dependent on whether the prior knowledge of the statistical characteristics of the measurement noise is known.In this paper,the effects of the inaccuracy of the measurement noise covariance on the filter performance are first analyzed briefly.The feature of the wavelet transform separating a noise signal into the signal and noise parts in real time is combined into Kalman filter.A new method,making the Kalman filter under unknown measurement noise covariance condition valid,is then proposed.The presented method can track the changes of the measurement noise covariance and estimate the covariance in real time.Finally,the applications of the proposed method for the information fusion are discussed.The simulation results verify the effectiveness of the proposed method.关键词：Kalman filter;measurement noise;divergence;wavelet1|2165|11更新时间：2025-07-16
- 摘要：With the particular research on thermal and visual images,a color image fusion algorithm using the contourlet transform is presented.Firstly,through the IHS (Intensity-Hue-Saturation) transform,the color visual image is converted from RGB color space to IHS space.Next,with the contourlet transform and weighted average fusion rule,the intensity component and thermal image are merged into a grayscale image,which is then linearly stretched to have the same mean and variance as the intensity component.Finally,the stretched grayscale fused image replaces the original intensity component,and the final RGB color fused image is achieved by the inverse IHS transform with the H,S and replacement component.On the one hand,with the proposed scheme,the contourlet transform as a new mathematical tool is introduced to image fusion area.On the other hand,the algorithm provided a new color image fusion strategy of thermal and visual images.The experimental results show that,with the proposed color fusion method,the fused image produced by the contourlet transform is of better quality than that obtained through the wavelet transform.Moreover,the color fusion approach obviously improves fusion performance over the traditional IHS transform fusion method.关键词：color image fusion;contourlet transform;wavelet transform;IHS transform2|2320|29更新时间：2025-07-16
- 摘要：This paper presents a new document segmentation algorithm,called context-adapted wavelet-domain hidden Markov tree (CAHMT) model,which extends a recently emerged wavelet-domain hidden Markov tree (HMT) model[1].The proposed CAHMT can achieve more accurate quality in document segmentation with low computation complexity.In addition to further improving the segmenting performance,we combine differential operator and the lowest frequency subband (called scale coefficients in wavelet transform) with CAHMT and produce much better visually segmentation quality than the HMT does.关键词：document segmentation;wavelet transform;hidden Markov tree model;context-adapted;differential operator;scale coefficients2|1170|7更新时间：2025-07-16
- 摘要：Recent years,decomposing an image into cartoon component (bounded variation component) and oscillating component (texture component) is an important problem in the field of image processing.The cartoon component of an image is modeled by a bounded variation (BV) function;the corresponding incorporation of BV penalty terms in the variational functional leads to solve PDE equations.Daubechies replaced the BV penalty term by a Besov term and wrote the problem in a wavelet framework.Following her ideas,we propose a new image decomposition algorithm based on the digital curvelet transform.By designing a digital curvelet transform algorithm and a scale-dependent thresholding rule,elegant and numerically efficient schemes are obtained.We can see that this approach is very robust to additive noise and can keep the image edges stable.关键词：image decomposition;ridgelet;curvelet;negative Hilbert-Sobolev space;besov space;total variation minimization2|1074|2更新时间：2025-07-16
- 摘要：A novel technique based on mutual information and thin-plate spline is proposed for the registration of coronary angiography images.This method not only resolves the uncertain problem of the calculating block size of traditional template matching method,but also removes the bad influence of the starting point of the optimization and insures to find global minimum.Experimental results show that the proposed method is able to achieve sub-pixel registration precision.关键词：elastic registration;angiography;mutual information;thin-plate spline2|1169|1更新时间：2025-07-16
- 摘要：To solve the problem of present iris location,a new iris location algorithm based on multi-scale local-direction contour detection is proposed.The multi-scale local-direction contour of iris image is decomposed by gabor wavelet,then the obvious vertical contour is reconstructed by selecting multiple scales and local directions coefficients.The binary image of main exterior iris contour is chose based on the location parameters of the iris inner contour,then the coarse exterior iris parameters are obtained based on the standard Hough transform.In order to improve the accuracy of iris location,the center and radius are decided accurately in a small scope by using Hough transform again.Comparative simulation results show that the performance of speed and robust is better than the existed method.关键词：iris location;Hough transform;nonlinear data fitting;multi-scale-direction decomposition2|560|3更新时间：2025-07-16
- 摘要：Global robust stability of a class of Cohen-Grossberg neural networks with multiple delays and parameter perturbations is analyzed.By way of constructing a suitable Lyapunov functional,the criteria expressed by the form of linear matrix inequality (LMI) are given for the global robust stability of equilibrium point.In addition,all results are established without assuming any symmetry of the interconnecting matrix,and the differentiability and monotonicity of activation functions.The simulation samples have proved the effectiveness of the conclusion.关键词：Cohen-Grossberg neural networks;multiple delays;parameter perturbations;robust stability;linear matrix inequality(LMI);lyapunov functional2|572|3更新时间：2025-07-16
- 摘要：The major signal in protein coding regions for most of genomic sequences is three-base periodicity.In this paper,we analyze this periodicity using wavelet transformation (WT) and propose a novel prediction approach for the protein coding regions of DNA sequences based on WT.This approach is able to predict and locate the coding regions simultaneously and is independent of training sets or existing database information.The validity of this approach is verified by a great deal of research results from theoretical analysis and experiments.The sensitivity and the specificity of novel approach reach 81% and 75% respectively.So,the prediction effectiveness is good.Especially,the sensitivity of novel approach is greatly improved compared with other techniques currently in use.关键词：DNA sequence;coding regions (CDS);Wavelet translation;prediction2|1033|4更新时间：2025-07-16
- 摘要：Present a security analysis of the Qian-cao-xues new threshold proxy signature scheme from bilinear pairings,which does not posses the strong unforgeability property,anyone including original signer can forge a valid threshold proxy signature for any message,at the same time,this scheme can't resist original signer changing attack.An improved threshold proxy signature scheme (denoted as scheme one) is proposed,which can resolve the security problem existing in the Qian-cao-xues new threshold proxy signature scheme.Based on scheme one,by combining vector space secret sharing with multi-proxy signature,a new and wider multi-proxy signature (denoted as scheme two) is constructed.Then scheme one becomes the typical representative of scheme two.In scheme two,the multi-proxy signature can be easily produced if an authorized subset of participants pool their secret shares,and it is impossible for them to generate a multi-proxy signature if an unauthorized subset of participants pool their secret shares.The validity of the partial signature and the multi-proxy signature can be verified by means of verification equations.Moreover the suspected forgery can be traced and the malicious participants can be caught.None of the possible attacks can successfully break this scheme.关键词：threshold proxy signature;bilinear pairing;strong unforgeability;original signer changing attack;vector space secret sharing3|955|9更新时间：2025-07-16
- 摘要：Two new hierarchical identity-based signature (HIBS) schemes are proposed.In random oracle model,the two schemes have the following results:The signature generation algorithms are efficient;They are provably secure and have good exact security against existential forgery for selective-ID attack;Signature size in the latter HIBS scheme is constant and independent to hierarchy depth;Both HIBS schemes have tight security reduction.关键词：identity-based signature;hierarchical;bilinear pairings;provable security2|511|12更新时间：2025-07-16
- 摘要：Recognizing and dealing with covert channel is the key requirement of TCSEC to evaluate the B2 or above products,as well as the key requirement of international standard CC to evaluate the EAL5 or above products.Now covert channel analysis is the main bottleneck of development of security information system with high security level.Based on the secure OS(SLinux) designing and implementing,this paper emphasis describes the identification processing,mainstream methods,bandwidth computation and analysis report of covert channel.It can give important edification on advanced secure information system research.关键词：covert channel;designing for security OS;recognizing and dealing with2|1147|7更新时间：2025-07-16
- 摘要：M-type stars play a significant role in the study of star evolution.The LAMOST project,the largest sky survey project being implemented in China,urgently needs a system for auto-recognizing M-type stars.This paper presents a novel method that can automatically recognize M-type stars.This method consists of three main steps:First,after a wavelet transform with 5 scales on the spectra in a selected wavelength region,the wavelet features are extracted from the transformed coefficients on the 5th scale.Then,the characteristic frequency of M-type stars and the locations of absorption bands are obtained accurately through the wavelet features.Finally,based on the results of the former step,M-type stars in all kinds of celestial bodies can be recognized.The extensive experiments with real observed spectra show that the proposed method is effective and the correct rate of this method is as high as 97.56%.关键词：astronomical spectra;detection of absorption bands;characteristic frequency;wavelet feature;wavelet transform2|1019|11更新时间：2025-07-16
- 摘要：In order to reduce the registration frequency and the handoff latency in LEO satellite IP networks,a VMR-based handoff management scheme was presented.When the handoff happens,the VMR associated with user segment network’s MR decided whether to transfer itself and register with the MR’s home agent by the cost function.The VMR’s data structure,the handoff operation procedure and the cost function model were presented,and the proposed method’s numerical simulation was carried on.The simulation result indicates that the proposed scheme can realize the isolation between the handoff and the registration procedure and be used in the LEO satellite IP networks.关键词：satellite IP networks;network mobility;VMR;handoff;simulation2|680|0更新时间：2025-07-16
- 摘要：Aiming at some limitations of traditional network formal description languages,a novel network architecture description language,named INSADL,is proposed and its design philosophy and major characteristics are introduced.By absorbing the main research results and practical experiences of software engineering,INSADL emphasizes on explicitly separating service from protocol that can effectively support the formal modeling of network architecture.As an example of INSADL’s application,how to specify the architecture of distributed streaming media service (DSMS) in INSADL is also introduced and discussed.By describing and analyzing the entity components,interaction connectors and architectural configuration of DSMS architecture,the formal description and architectural analysis capabilities of INSADL are demonstrated and validated.关键词：network architecture;architecture description language;INSADL;streaming media service2|1122|1更新时间：2025-07-16
- 摘要：The vector finite element-boundary integral (FE-BI) method is adopted to formulate the radiation problem for cavity-backed patch antenna.The well-conditioned asymptotic waveform evaluation (WCAWE) is integrated into the FE-BI method to realize fast computing of input impedance of patch antenna over a wide frequency band.In contrast to classical AWE techniques,WCAWE is robust and doesn’t stagnate.Moreover,unlike the linearized Krylov subspace methods,WCAWE doesn't require the neglection of higher order terms or the introduction of extra degrees of freedom.Numerical results for input impedance are presented to illustrate the robustness of the WCAWE.关键词：higher order vector basis functions;finite element-boundary integral method;WCAWE;antenna2|1124|1更新时间：2025-07-16
- 摘要：Detecting the order of multipath channel is the first step of a parametric channel estimator in wireless communication.It is critical to improve the performance of system.However,the methods to estimate the order of multipath are mainly based on Akaike information theoretic criterion (AIC) or minimum description length (MDL).They perform good at high SNR but bad at low SNR.In this paper,an improved constant false alarm rate algorithm based on forward-backward averaging (FB-CFAR) is proposed to detect the order of multipath channel.Simulation results in an OFDM system demonstrate that this algorithm can improve the probability of correct detection at low SNR effectively.关键词：parametric channel model;wireless communication;FB-CFAR;order of multipath channel2|888|0更新时间：2025-07-16
- 摘要：It is an important challenge to find out a suitable key establishment scheme for wireless sensor networks due to limitations of power,computation capability and storage resources.Many schemes based on random predistrubution technique and public key cryptography are investigated.Recently,a practical identity-based encryption technique is proposed.This paper presents an identity-based key establishment scheme for key predistribution and exchange in wireless sensor networks.It reviews first the identity-based encryption,particularly,the Boneh-Franklin algorithms.It describes a novel key establishment scheme based on the basic Boneh-Franklin and Diffie-Hellman algorithms.It discusses the efficiency and security of our scheme by comparing with random key assignment technique and symmetric key technique.关键词：identity-based cryptography;network security;Diffie-Hellman key exchange;wireless sensor network3|1845|34更新时间：2025-07-16
- 摘要：A novel traffic-based approach of quaternion (O,A,P,R) for failure measuring in transport network is put forward.In order to measure the extent of traffic lost and potential risk incurred by failures,two metrics,Service Outage Index (SOI) and Service Affected Index (SAI),are defined.They are weight ratios of lost services over total services and affected services over total services respectively.And by connecting these discrete assessment values of SOI and SAI,time-varied continuous assessment functions come into being.Based on them,a new approach of quaternion (O,A,P,R) for failure measuring is proposed.In the quaternion,four components represent four corresponding aspects of failures:services lost,potential risks,failure processes,and remarks.The quaternion and other approaches are applied into an example network which is a part of one carrier’s transport network in China,and the comparison results in whatever single failure or multiple failures scenarios show the quaternion is better than others.关键词：failure measuring;transport networks;service outage index(SOI);service affected index(SAI);quaternion2|951|2更新时间：2025-07-16
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