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摘要：Scheduling algorithms make a great impact on the performance and implementation complexity of switch architecture.Traditional maximal matching (MM) algorithm cannot get a proper balance between these two factors,so in this paper we propose a new kind of Extended Maximal Matching (EMM) algorithm.By using different weight parameters,EMM algorithm can derive different kinds of algorithms.We prove that any EMM(2) algorithm with data speedup of 2 can deliver 100% throughput,and show it can also achieve almost the same delay performance as ideal Output Queueing (OQ).Furthermore,under the situation of non-speedup,through simulation we show EMM algorithms,with more than two weight parameters,can greatly increase the throughput performance of MM algorithm.  

摘要：The contention-collision cancellation access mode in multi-star LAN can be divided into six different models according to its working mechanism.The mathematical analysis for the Ⅰth,Ⅱth,Ⅲth,Ⅳth and Ⅴth models have been presented and discussed.In this paper,the Ⅵth system model under heavy load is studied,gets expressions for the transfer probability of the customers P_ij,the mean number of customers in the steady state ,and the mean detained time of the customers in the system W,and so on.Simulation experient results are compared with the Ⅱth and Ⅳth one.So far,the theory foundation of the contention-collision cancellation access mode has been established for its application in star LAN.  

摘要：Compared with the previous standard,the compression performance of H.264 has significantly improved because of different block-size motion estimation.However,encoder using above technology becomes extraordinarily complex.Thus,a real-time video encoder based on H.264 faces enormous challenges.Making full use of the spatiotemporal correlation of video and similar motion between the different-size block,according to the central-biased characteristic of motion vector,a fast motion estimation algorithm appropriated for H.264 is proposed in this paper.By effective prediction of search window center point,adaptive selection of search patterns and termination of the search,the speed of the proposed algorithm speedups 95-247 times than full search and 4.1-6.3 times than the fast motion estimation algorithm recommended in H.264 while maintains similar distortion performance.  

摘要：Present service management models can not satisfy the emerging requirements along with the fast NGN services’ development.This paper presents a novel universal NGN service management model-USMM,which is independent of network layer aiming at network independent service layer management.NGN service management function domain is analyzed based on multi-level and multi-dimension mode which makes it easy to extend and deepen.Then a uniform service management objects description based on UML is presented,including service management processes,service management shared information/data,service management features and service management relationship.The objects description works as a meta-model to guide the development of NGN service management system.Through the comparison with other four service management models,the value of USMM is demonstrated.  

摘要：The conception of multi-mode reconfigurable terminals (RT) is given.And the basic functional architecture of RT is designed,so that RT could communicate with different kinds of radio access networks (RANs).A scheme for RT selection of RANs and radio access technologies (RATs) is proposed,which is co-operated by RT and RANs.The RT,which is the initiator of connection establishment and link changes,is responsible for processing the information associated with the local wireless environment.Then it transmits the parameters of user requirements to the network.The implement of the above functions is based on the three levels Bayesian Network model for RT’s radio access management.The network,which has the final decision-making right of RATs selection,takes charge of the issues related to the network composition.Finally,computer simulations proved the valid of this scheme.  

摘要：Ultra-wideband is of particular interest worldwide in short range wireless communication with two major propo-sals:direct-sequence ultra wideband (DS-UWB) and multi-band orthogonal frequency division multiplexing (MB-OFDM) ultra wideband.MB-OFDM is considered a mature proposal.A novel design of dual-carrier orthogonal frequency division multiplexing (DC-OFDM) is presented for MB-OFDM UWB RF system,in which two adjacent sub-carriers are adopted to realize ultra wideband communication.To cut down difficulties in hardware implementation and system complexity,combination/divider ways is used in the two sub-carriers in intermediate frequency.Moreover,some key parts in UWB RF receiver are designed,including low noise amplifier,frequency synthesizer as well as RF demodulator.In the end,a DC-OFDM UWB receiver experiment demo test bed is set up.Test results show that the researched RF receiver had been developed with the measured results meeting FCC RF standard perfectly,and the design could be used in other wideband communication systems.  

摘要：One of the key problems for Wireless Sensor Network (WSN) is the design of Medium Access Control (MAC) protocol.MAC protocol controls the activity of wireless communication module of sensor nodes,which is the major consumer of sensor energy.The energy efficiency of MAC protocol makes a strong impact on the network performance.TDMA-based MAC protocol is inherently collision free,and can rule out idle listening since nodes know when to transmit.In this paper,we present ED-TDMA,an event driven TDMA protocol for wireless sensor network.ED-TDMA improves channel utility by changing the length of TDMA frame according to the number of source nodes,while saving energy with bitmap-assisted TDMA schedule.In addition,ED-TDMA employs intra-cluster coverage to prolong network lifetime and to improve system scalability.Simulation results show that ED-TDMA performs better for wireless sensor network with high-density deployment and low traffic.  

摘要：A low computational complexity differential detection scheme for Multiple Input Multiple Output system is proposed which is based on the full rate quasi-orthogonal space-time block codes.The transmitted bits are jointly mapped to construct quasi-orthogonal space-time block codes and the codes are used to perform differential encoding.At the receiver,Maximum Likelihood (ML) criterion is used to differentially decode the symbol pairs.The constellation set and joint constellation mapping defined in this paper simplify the detection algorithm and reduce the detection computational complexity.  

摘要：Multiuser interference cancellation decision feedback equalizer with error feedback filter (MIC DFE-EFF),for DS-CDMA,based on multiuser feedback structure,has been proposed.It has solved this problem that conventional adaptive decision feedback equalizer has higher bit error rate (BER) and smaller capacity.In this paper,we depict the structure of MIC DFE-EFF,analyse its algorithm and relative algorithm.It can deal with intersymbol interference (ISI),multiple access interference (MAI) and noise at the same time.Simulation results show that the proposed MIC DFE-EFF outperforms conventional DFE、DFE-EFF and PIC at bit error rate (BER) performance,also its capacity is larger than DFE and DFE-EFF.Although MIC DFE-EFF increase computational complexity compared to DFE-EFF,its computational complexity is less than PIC.  

摘要：With the combination of binary tree,segment table and route bucket after sufficient and thorough analysis of the hierarchy of IPv6 address,IPv6 address allocation policy and the characteristics of real live IPv6 backbone BGP routing tables,we propose a multi-stage algorithm for IPv6 routing table lookup in this paper.Compared with previous algorithms,the proposed scheme performs faster,occupies less memory,scales better,and supports incremental update.The evaluation results show that the sample software implementation of the proposed algorithm can forward at a rate of 16MPPS (Million Packet per Second),or 10Gbps for 80-byte minimal IPv6 packets on a PC with Pentium4 2.4GHz CPU,512M DDR333 memory,and Linux operating system.The sample implementation only needs several hundreds of kilobytes memory for the current real live IPv6 backbone BGP routing tables.  

摘要：In this paper,we suggest some parameters to evaluate the performance of various PMTU discovery methods,such as the precision,the consuming time,and the number of packages to be sent,etc.And we also suggest a new efficient and agile method called Hierarchical-Test based Empiristic-data to detect the PMTU.Then we elaborately discuss the quantitative analyses method of the algorithm.Meanwhile,we have realized the algorithm under Linux operating system environment,and have done some real-world tests based on 58 websites given stochastically within the Education and Research Network of China.Finally,we further analyze the performance of the method through these data that we have attained by experiment.  

摘要：It is a long outstanding conjecture that any (2n-1)-stage shuffle-exchange network (Omega network) is rearrageability for 2^<em>n×2^<em>n.Since then many researchers have attempted to solve this conjecture without success.A new result on the sufficiency proof has been established by Hasan.however,nobody have pointed out this proof to be incorrect.To clarify this fact is one of the objectives of this paper.The case n=3 was proved by many researchers.Using a constructive approach,this paper also proves that when n=4 the 7-stage 16×16 shuffle exchange network is rearrageability.The model of the balanced tree to avoid internal conflict,the repetition of permutations using connective graph and cycle graph,the concept of symmetry graph and equivalent transform are also presented in this paper.Based on the graph composition and bipartition the permutations 16×16 are divided into five classes,and total five assignment algorithms are proposed.These algorithms are more simple and clear and to be programmed.The techniques used for n=4 may provide useful hints for general case n＞4.  

摘要：A data-hider can reduce the amount of alterations necessary to be introduced into a cover signal for data hiding by using stego-encoding techniques.In this paper,construction of the generalized stego-encoding technique is described in a form of sparse representation.With this representation,a series of stego-coding methods are obtained,among which the previously introduced matrix encoding may be viewed as a special case.It is then demonstrated that a suitable combination of different stego-encoding schemes can provide improved performance under a given ratio between the amount of host data and that of secret data,which is better than the performance of the matrix encoding and the running encoding schemes.  

摘要：when GPS is used to determinate the inter-satellite relative position and the precise dynamic model of inter-satellite relative movement cannot be obtained,the least square method is usually used in the post data processing,but in practice,the stochastic model used by LS method do not take into account the characteristic of heteroscedastic,space- and time-correlated of real GPS measurements.In order to solve this problem and improve the positioning precision,this paper proposes a new relative positioning method,which first founds the spline function model based on the continuity of the relative position,then eliminate the time correlation of GPS double-difference measurements based on epoch-difference theory,then uses MINQUE to solve variance-covariance components of de-correlated GPS measurements iteratively,finally uses LAMBDA to fix the integer ambiguities and determinates the relative position.The experiment simulation gets two conclusions:(1)spline function model can not only benefit eliminating time correlation of GPS measurements in dynamic condition,but also improve the relative positioning precision greatly because of its functions of saving the number of unknown parameters and smoothing noise;(2)the iterative stochastic modeling using MINQUE method can improve relative positioning precision more based on spline function model.  

摘要：This paper presents a new strategy of particle-pair (PP) for vector quantization (VQ) in image coding.In this strategy,two particles are combined into a particle-pair based on conventional particle swarm optimization (PSO) algorithm.At each iteration,the particle-pair performs basic operations of PSO (velocity updating and position updating) and conventional LBG algorithm in sequence.The codevectors flying over the boundary are replaced with the training vectors,which have large distortions.This strategy prevents the particle from being trapped in a local optimum,memorizes and estimates the best direction the particle moves toward to find the optimum codebook design.The codevectors are scattered reasonably both in high density distribution regions and low density areas of the training vector space.Experimental results have demonstrated that the performance of this new algorithm is much better than that of FKM,FRLVQ,FRLVQ-FVQ consistently with shorter computational time and higher convergence rate,and the dependence of the final optimum codebook on the selection of the initial codebook is reduced effectively.  

摘要：In this paper we propose a blind super-resolution image restoration algorithm based on Support Vector Machines (SVM).Firstly,Sobel operator and local variance were used to extract feature vectors that contain information about different Point Spread Functions (PSFs) and SVM was used to classify these feature vectors.The acquired mapping between the vectors and corresponding blur parameters provided the identification of the blur.After blur identification,a super-resolution image was reconstructed from several low-resolution images obtained in different illumination conditions.The reconstructed image has high spatial resolution and dynamic range.We also propose a sub-pixel registration algorithm based on Retinex theory.Simulation results demonstrate the effectiveness and higher performance of the proposed method in both objective measurements and subjective visual quality.  

摘要：Based on the properties of NonSubsampled Contourlet Transform,shift invariance,multiscale and multidirectional expansion,a novel multisensor images fusion method was proposed.The proposed method was applied to the multifocus and the multispectral images fusion in the experiments respectively.We gave the subjective judgment and numeric measurement of the fusion image based on visual effect and information indexes.To evaluate the performance of the proposed algorithms,we compared our results with those of the algorithms,such as contourlet transform,wavelet transform and principal component analysis.The simulation results indicate that the proposed method outperforms the others in terms of both visual quality and objective evaluation criteria,and maintains much more detail information as well.At the same time,the proposed algorithm widens the applications of the NSCT.  

摘要：A new method for image de-noising which colligated the strong point of Contourlet transform and the magnitude of the detail of image in every scale and direction.This paper deals with the problem of snuffing out the Contourlet coefficients to exceed,and it also can solve the problem of taking no consideration of image details.Experiment on image de-noising shows that:compare to the wavelet threshold,Contourlet threshold and multi-scale threshold using Contourlet transform,the two methods both pick up the image detail better and improve the peak signal-to-noise ratio.  

摘要：The Empirical Mode Decomposition (EMD) developed by Huang etc.of NASA is an advanced method for signal analysis.But there is an involved end issue in the course of getting two envelops of the data using spline interpolation.In this paper,a new self-adaptive method to dealing with the end issue is proposed.Generally,it extends the extrema sequence near the ends of the data by the most suited sequence in the inner data.For the chosen inner sequence has the most similarity of tendency with the ends,the data extension is reasonable.After the extension,the spline does not swing at both ends of the data.The result of experiment proved that the new method can be used to solve the end issue effectively.  

摘要：The Discrete W Transforms (DWT) have been widely used in the field of digital signal and image processing.Due to its high computational complexity,many fast algorithms for computing the DWT have been reported in the literature to improve the computational speed and hardware complexity.In this paper,a recursive algorithm for computing the DWT is proposed.By using Clenshaw’s recurrence formula,we derive an efficient method for computing the type-II,-III,and -IV DWT of sequences with general length.The results indicate that the proposed algorithms achieve a simple computational structure which is particularly suitable for parallel VLSI realization.  

摘要：A nonparametric fMRI data noise analysis procedure is proposed in the paper.The fMRI noise is classified into structured and unstructured noise by their temporal characteristics,and their impacts to efficiency of statistical tests are discussed separately.The canonical correlation analysis technique is exploited to extract the underlying structured signals from which the neural response signals are picked up by surrogate test based on reduced autoregression model.The temporal autocorrelation of unstructured noise is eliminated by the randomization method without changing the spectral power.The spectral power of noise in low frequency range descends and the "white noise" assumption applies better after the application of the procedure.Two kinds of simulation data sets are generated and to which the F-test based on multitaper spectral analysis is applied to test the validity of the technique.Twenty sets of fMRI data are then processed and some task-related areas go undetected in original data are gotten.  

摘要：The phenomenon of Chaos can be observed extensively in both nature and human society.The fundamental characteristic of chaotic behavior is its unstable trajectory,and the sensitive dependence on initial conditions,so it is also referred as the butterfly effect.How to exploit the beneficial aspect of Chaos has become an important part of nonlinear science.In this paper,the issues of application of Chaos theory to error control coding are addressed.As the interleaver and parity-check matrix respectively play a critical component in Turbo codes and LDPC codes,we conduct the research on the application of chaotic theory to the design of them.We present the improved designing methods of interleaver and parity check matrix according to the immanent randomness of the Henon chaotic model for Turbo codes and LDPC codes respectively.Simulation results show that the Henon method can yield higher coding gain compared with the traditional Turbo codes and LDPC codes,showing that Henon chaotic model a good tool for constructing good codes.  

摘要：An improved equivalent circuit model for ferroelectric liquid crystal (FLC) in which the anisotropic electro-optical properties are presented is proposed to simulate the AC stabilization technology.The coupling effects of electric fields to dielectric tensor as well as the surface anchoring forces due to alignment layers are included in the model by equivalent current sources to make it has the capability in optical response prediction and dynamic analysis when dielectric anisotropy of FLC is of a relatively high value.Optical responses in cases of positive anisotropy and negative anisotropy,and with AC stabilization technology are displayed,and the dielectric torque,ferroelectric torque and polarization reversal current are given.The simulation results indicate a good quantitative agreement with the theoretical analysis and the published results.  

摘要：The Terahertz (THz) technology is currently a scientific frontier in the world.In this paper,a review of THz techniques is presented that include THz sources,detectors,signal processing methods,and THz signal’s applications.The future investigations on terahertz signal processing and analysis are also discussed.  

摘要：This paper proposes a differential encoding and detection scheme for distributed MIMO system where channel estimation is not needed to know the channel knowledge.At the transmitter,space-time codes are constructed with symbols which are differentially modulated by phase.The phase information is detected using two consecutive received signal vectors.The proposed scheme is evaluated in different channel propagation delay cases,and the simulation results show that the bit error rate (BER) performance is nonidentical in different propagation delay cases:the BER first decreases and then increases as the channel propagation delay changes from 0.1 symbol period to 0.9 symbol period.The BER performance is better when the propagation delay is about 0.6 symbol period,and there exists a delay case when the system achieves better performance.  

摘要：As for a search engine,keeping up with the evolving Web is necessary.We concern about modeling on an effective Web page collecting policy and propose an adaptive refresh strategy based on the relevance,which is used to adjust the process.On one hand,we think the refresh behavior follows the properties of the Poisson process and analyze the strategy on how to crawl the Web effectively.Further,the relevance is on the basis of the affiliation detecting and the contents analysis.It is used to adjust the process.This makes the process more targeted.The experimental results validate the feasibility of the approach.  

摘要：Proposing a novel handoff algorithm based on fuzzy logic and pre-decision method,which can adapt to the dynamic network condition and reduce the system load,is applied to the All-IP heterogeneous network for vertical handoffs.And it is combined with the forward difference prediction for the signal strength of next time to improve the handoff accuracy.The results of simulations indicate that the proposed algorithm can make accurate handoff decision and eliminate the ping-pong effect in the process of vertical handoffs.  

摘要：We can find the first harmonic current component is1 of injecting to the nonlinear networks by using fundamental-wave balance principle,when sinusoidal voltage source Us is applied to the proper port of the nonlinear network.The frequency and amplitude of sinusoidal voltage source is called fundamental harmonic solution,when is1=0.If n-fundamental harmonic solution can be found,then n-periodic solution of original network certain exist correspondingly.If first harmonic solution is nonexistent,the original network has no periodic solution also.Taking the Colpitts circuit as example,the close relation between reactive power balance and periodic oscillation can be shown.Chaotic oscillation shape and properties of Chua’s circuit can be explained by the fundamental-wave balance principle.The universality of the conclusion can be extended to the three dimensional nonlinear network .Its correctness can be verified by the Simulink.  

摘要：Based on quantum genetic algorithm(QGA),a novel improved quantum genetic algorithm(NIQGA)to solve combinatorial optimization problem is proposed.To make full use of interference and entanglement characteristics of quantum state,dynamic step length in adjustment of angle of quantum gate,quantum crossover operation and quantum mutation operation are introduced,therefore high efficiency for optimization is achieved.Two typical combinatorial optimization problems—0/1 knapsack problem and route selection problem,are adopted to confirm the performance of NIQGA.Experimental results show that compared with GA and QGA,NIQGA is characterized by fast convergence rate and excellent capability on global optimization,especially better performance for combinatorial optimization problem with less correlation of genes.  

摘要：The functional connectivity between different brain regions is of importance for human brain to accomplish cognitive tasks,and it may appear as correlated temporal behavior of neural activity.It will help to investigate the brain underlying mechanism to noninvasively localize coherent sources which underlie the scalp EEG recordings.Classical MUSIC(Multiple Signal Classification) method has difficulty on localizing coherent sources.This paper presented a class of MUSIC for coherent sources localization in transformation data space.At first,the coherent source region is coarsely estimated by a prior knowledge or other mapping methods.And then,a transformation matrix designed to suppress the source activity is constructed.At last,using the transformation matrix to project the scalp EEG recordings into a new transformation data space,where the coherent sources can be localized by classical MUSIC method.Computer simulations reveal that under different levels of noise,in contrast to other coherent source localization algorithms,the proposed method has rather less mean localization bias and run much faster.  

摘要：This paper investigates the probability distribution of speech components as well as the correlation characteristic between adjacent components,and presents a new speech model for enhancing noisy speech in adaptive KLT domain.Based on this model,a novel speech enhancement algorithm using MAP estimation is proposed,which incorporates the inter-frame correlation information as a form of joint probability density function into MAP under Gaussian model assumption for speech and noise components.The obtained estimation result keeps simple and avoids deficiency of classic approaches in enhancing noisy speech.In simulations with speech signals degraded by various noises,the proposed algorithm shows improved performance for a number of objective and subjective measures.  

摘要：Distributed video coding(DVC) is a new video compression paradigm based on two key information theories:Slepian-Wolf and Wyner-Ziv theorems,and it has the advantage of very lightweight encoder,high compression efficiency and inbuilt robustness.In this paper,pixel-domain Wyner-Ziv video algorithm,which is a typical DVC scheme,is analyzed at first.Then a performance improved method for pixel-domain Wyner-Ziv video coding system is presented.The proposed method,without sacrificing the encoder complexity,can calculate high quality side information using bi-directional motion estimation and reconstruct decoding frames using side information by joint iteration function based on Huber-Markov random field.Simulation results show that a better visual quality and 2dB average gain of Power Signal-to-Noise Ratio (PSNR) can be achieved with the proposed method at the decoder.  

摘要：The purpose of this paper is to evaluate the blur extent of the motion blurred SAR image.Combined with the averaging operation,a simple adaptive filter was proposed to identify the motion blur extent by using the autocorrelation method,which is expected to be the measure of the motion blurred SAR image.  

摘要：In this paper,we propose an approach to automatic extraction of spatio-temporal salient unit from video sequences.Firstly,a class-related feature granulation algorithm is proposed,which can map original feature space to concept space based on fuzzy information granular.To detect spatial salient regions,segmented homogenous regions are classified according their prominent importance.Then,salient regions are tracked and the results of tracking are sequences of temporal coherent regions,called spatio-temporal salient unit.Experimental results verify efficiency of proposed approach in spatial and temporal aspects.  

摘要：Pseudorandom sequence have been widly used in stream cipher,channel coding,and spread spectrum communication.m sequence is a excellent pseudorandom sequence.Based on m sequence ,we first present reconstructing it’s state transition diagram and gained the state transition diagram of the new sequence called m subsequence in this paper.We prove that the first class m subsequences is existent,and present first class of m subsequences feedback functions.In the end we analyze m subsequences properties and affirm that possess with ideal balanced property、run property 、periodic property and good linear complexity.Statistic results show that m subsequences autocorrelation property have δ (t) function characteristic.More new m subsequence can be obtained by using this constructing method.