最新刊期
卷 44 ， 期 11 ， 2016
- 摘要：L7-filter is a widely used traffic classification system which relies on regular expression matching based deep packet inspect method and can identify network traffic by inspecting string patterns hidden in the packet payload.However,due to considerable computation and storage expenditures,existing L7-filter software and hardware solutions could not offer sufficient performance in the context of 40 Gbps and higher speed networks.Based on analysis of common features of the L7-filter protocol patterns,this paper proposes a hardware-accelerated method which is for achieving high performance and includes customized data structure,optimization and matching architecture.To validate the proposed method,a hardware prototype on Virtex 6 FPGA card is implemented and tested.Experimental results show that the prototype can scan network traffic at a typical rate of about 115Gbps.关键词：traffic classification;regular expression matching;100Gbps;FPGA305|981|1更新时间：2025-07-16
- 摘要：Nighttime haze removal is more difficult,since nighttime hazy images contain degradation more serious than daytime's due to illumination,resulting in lower brightness,lower contrast,uneven illumination,and chromatic aberration,etc.Depending on imaging law of nighttime hazy image,a novel dehazing algorithm based on illumination estimation is presented.Firstly,the uneven illumination is removed by estimate the illumination map.Secondly,an entropy-based scheme for nighttime images is proposed to obtain transmission map.Finally,the color of illumination is estimated by statistics of source regions.The experimental results show that the proposed algorithm can effectively remove the uneven illumination effect,increase the image contrast and improve the image visual effect.关键词：illumination estimation;dehazing;color constancy249|756|9更新时间：2025-07-16
- 摘要：When using remote sensing for land cover mapping,super-resolution reconstruction is widely used.Prior models containing the features of land cover maps can constrain the uncertainty of reconstruction.These prior models can be used properly by multiple-point statistics (MPS) by extracting the intrinsic features from them,and copying these features to the simulated regions.However,because traditional MPS methods based on linear dimensionality reduction are not suitable to deal with nonlinear data,isometric mapping (ISOMAP) is introduced in MPS to reduce the dimensionality reduction of nonlinear data and then these lower-dimensional data are classified.Current data event and the average of every classified class are compared so that a pattern can be extracted from the class that is closest to the current data event.Besides,the low-resolution original image is viewed as soft data for generating super-resolution land cover maps.Tests show that the super-resolution reconstructions of land cover maps have the similar structural features with those of reference images.关键词：land cover;remote sensing;multiple-point statistics;isometric mapping;super-resolution reconstruction275|536|1更新时间：2025-07-16
- 摘要：The preservation of structural information and polarimetric scattering properties is the major obstacle in despeckling for Polarimetric Synthetic Aperture Radar(PolSAR)images.Speckle reduction for PolSAR images using hybrid features similarity,to establish a method for extracting structural features by analyzing the structural feature and polarimetric information of PolSAR data,is proposed.The proposed method introduces structural characteristics as well as polarimetric scattering characteristics into the speckle reduction and in order to preserve them efficiently after filtering.The test results of real airborne SAR data show the effectiveness of the algorithm.关键词：polarimetric SAR;speckle reduction;structure similarity;polarimetric scattering characteristics201|444|3更新时间：2025-07-16
- 摘要：A blind identification algorithm for image copy-paste tampering with geometric invariance was proposed in this study.Firstly,gray level and gray structure are defined,the image is divided into blocks according to the gray levels of pixels,and the suspicious blocks in the image is positioned through the gray structure;Secondly,phase correlation is made for each group of suspicious block based on logarithm polar coordinate transformation,and the tampering regions are located preliminarily;Finally,the rotation angle,scale and translation measurements are calculated precisely,and the tampering regions are positioned.The experimental results show that our algorithm performs well against copy-rotate/scale-paste tampering,and its detection efficiency and robustness are better than the existing algorithms.关键词：blind forensic;copy-paste tampering;logarithm polar coordinate transformation;phase correlation195|861|4更新时间：2025-07-16
- 摘要：Many researchers focus on how to detect overlapping communities effectively and accurately when coping with large-scale networks in recent years.This paper proposes a novel overlapping community detection algorithm based on a multiple label propagation strategy,called MLPS algorithm.Firstly,MLPS selects a set of nodes as initial seeds by using Influence Maximization Model,each of which is assigned a unique label;Inspired by strategy based on similarity and influence diffusion,MLPS incorporates with these two strategies to guide the process of label propagation;Finally,nodes with the same tag are divided into one community after propagation.Experimental results on synthetic datasets and real networks illustrate that MLPS has both high accuracy and modularity at the same time.In addition,another algorithm named Structural Holes between Communities Detection Algorithm (SHCDA) is presented on the basis of the output of MLPS.SHCDA computes the scores of overlapping nodes who serve as structural holes by analyzing the overlapping structure and position feature of overlapping nodes,and then selects top-k structural holes as the output.Experimental results on different datasets show that SHCDA gets the best accuracy.关键词：complex networks;overlapping community;multiple label propagation;structural holes detection164|493|2更新时间：2025-07-16
- 摘要：Opportunistic Networks are delay tolerant self-organized networks with sparse nodes,where the message propagation depends on the cooperation of nodes to fulfill a "store-carry-process-and-forward" fashion by leveraging the mobility of nodes,because there does not exist a complete path from the source to the destination in the most time.To achieve the communication of nodes in mutually disjoint clusters,we propose a Cluster Movement Model with Threshold (CMMT) and routing algorithm (CBSW),which is Cooperative Binary Spray and Wait routing algorithm based on the Ferry nodes and cluster nodes cooperation.This routing algorithm reduces of the redundancy of communication and store the cost,as well as if the destination or Ferry nodes are not found in the spraying phase,nodes carrying a message copy will forward the message only to its destination in the Waiting phase nodes etc.Simulation results demonstrate the effectiveness of the proposed CBSW protocol in terms of high delivery ratio,low overhead and small average delay.关键词：opportunistic networks;movement model;cooperation;routing algorithm205|450|2更新时间：2025-07-16
- 摘要：Micro-Doppler generated by rotation of wheels is a unique characteristic of wheeled vehicles.Extraction of micro-motion parameters of truck,etc.will offer important proof for classification and recognition of ground vehicles.Firstly,the echoes model of truck was established under narrowband signal,the mathematic expressions of Doppler induced by non-rotation scatterers and micro-Doppler induced by rotation scatterers were deduced.Secondly,corresponding dictionary bank consists of micro-motion parameters was constructed for matching pursuit,and convex optimization model under noisy condition was established for extraction of micro-motion parameters.Thirdly,for avoiding the heavy computation and storage burden induced by parameters extraction based on overcomplete dictionary,the smaller dynamic dictionary was structured after deduction of the convex function about micro-motion parameters set,the accurate and faster parameters estimation was obtained by dynamic adaptation of the dictionary and iterative approach to optimal solution under Least Square criteria.The effectiveness and robustness of the method were proved by the simulation results.关键词：truck target;micro-Doppler;micro-motion parameters estimation;dynamic dictionary168|424|2更新时间：2025-07-16
- 摘要：Background subtraction algorithm is a kind of main moving object detection framework,but it is too difficult to build a model with short establishing period,high reliability and good robustness.From the perspective of scene perception,a technique for object detection based on the framework of background subtraction is proposed.To improve the reliability of initial model,the potential foreground pixels in background,which are obtained on the basis of stable structural information in the former two frames,are replaced by the nearest neighbor pixels belonging to background,when the initial model is being established in the second frame.Integrating color information with binary feature,a two-stage classification decision mechanism is proposed,meanwhile the local decision threshold and update frequency are adaptively adjusted in accordance with the texture complexity of pixels neighborhood.Subsequently,a feedback mechanism for misclassification is presented in the update model phase.Experimental results using challenging public video sequences show the effectiveness and superiority of the proposed method,compared with other state-of-the-art tracking approaches.关键词：object detection;scene perception;binary feature;feedback mechanism187|483|1更新时间：2025-07-16
- 摘要：In order to solve the problem of setting sparsity level in sparse representation-based target detection algorithms,this paper proposes a novel collaborative representation-based algorithm for hyperspectral target detection,and then extends it into a kernel version.The key idea is that a background pixel can be approximately represented as a linear combination of its surrounding neighbors (background dictionary),while a target pixel can only be approximately represented as a linear combination of its surrounding neighbors and the prior target spectrums (union dictionary).First the unknown pixel is collaboratively represented by the background dictionary and union dictionary,respectively.Then targets can be determined by comparing the reconstruction residuals.Experimental results on real hyperspectral data set demonstrate the effectiveness of our proposed detector as well as its kernel version when compared with other algorithms.关键词：Target Detection;collaborative representation;kernel collaborative representation;hyperspectral imagery219|404|1更新时间：2025-07-16
- 摘要：Multi-objective optimization algorithms with preference are an important branch of multi-objective optimization.Its main aim is to find the Pareto optimal solutions in local regions interested by Decision Makers.Based on the idea of MOEA/D algorithm to search the Pareto front according to uniformly distributed weight vector,this paper proposes a weight vector based multi-objective optimization algorithm with preference.In the proposed method,the weight vector with preference is designed,by which the solutions around the preferred point interested by Decision Maker are found.Compared with existing algorithms,the simulation results verify that the proposed method can support multiple reference points,flexibly control the extent of preferred region,have no special requirement of the position of preference points and achieve better converge.关键词：multi-objective optimization;multi-objective optimization algorithms with preference;weight vector;preferred solution280|575|3更新时间：2025-07-16
- 摘要：In order to characterize the reliability of CMOS inverter,a kind of low-frequency noise model is deduced in detail by using the characteristics of load current and output voltage,based on the carrier fluctuation theory,and the accuracy of the model was verified by experimental data.The experiment results indicate that load current power spectral follows the changing rule of the 1/f noise,decreasing with the increase of frequency;the normalized noise power spectral density of load current decreases with the increase of the channel width or length.Using the experimental data,the relationship between 1/f noise and interface trap state densityof CMOS inverter is established.Verify that the 1/f noise can be used to characterize the reliability of CMOS inverter.It is proved that the larger interface trap state density,the larger the noise magnitude,leading to the degradation of device reliability and significant rise in device invalidation rate.That provides a feasible and effective method for evaluating the reliability of CMOS inverter.关键词：CMOS inverter;low-frequency noise;reliability;defect151|455|1更新时间：2025-07-16
- 摘要：Area and SER (Soft Error Rate) evaluation models at logic level are proposed for area and reliability optimization of MPRM (Mixed-Polarity Reed-Muller) circuits,the trade-off between area and reliability is achieved by using Pareto dominance based multiobjective optimization.The area is computed by decomposing the XOR part of MPRM circuit as trees of XOR gates and counting in XOR gate sharing among multiple outputs.The SER is computed by using signal probability and fault propagation techniques,and taking into account the logic masking effects and correlations among signals in the circuit network.Based on the proposed area and SER evaluation models,the Pareto optimal set for area and SER of MPRM circuit is obtained by using polarity optimization method with Gray code based exhaustive search strategy,the final solution is selected by using a metric called efficiency factor.Experimental results by using a set of benchmark circuits from MCNC show that,in comparison with the MPRM circuits with minimized area,the selected MPRM circuits have improved reliability with less area overhead.关键词：MPRM circuits;reliability optimization;area optimization;analytical SER evaluation model;Pareto dominance;multiobjective optimization194|497|6更新时间：2025-07-16
- 摘要：RAM is one of the most important macro-cells of FPGA,and RTL synthesis plays a critical role on the effective use of RAM resources in FPGA development.For the difficulty of multi-resources and multi-targets in RAM technology mapping of RTL synthesis,this paper presents a method of technology mapping for FPGA on-chip RAM.In this method,an unified technology-independent RAM model is proposed,and based on this model,RAM technology mapping is performed through a series of steps,including model set-up,mode-matching,cost calculation,and binding.When applied in RTL synthesis,this method is capable of mapping various styles of RAM RTL descriptions into the most appropriate type and number of FPGA on-chip RAM resources.Experimental result shows that this method achieves comparable RAM mapping results as the mainstream FPGA RTL synthesis tools-Synplify and XST,this technology has been integrated into the self-developed RTL synthesis-Hqsyn and has been applied into the FPGA market.关键词：FPGA(Field Programmable Gate Arrays);RTL(Register-Transfer-Level) synthesis;on-chip RAM;technology mapping149|428|1更新时间：2025-07-16
- 摘要：In this paper,a new kind of pedestrian detection method is investigated;the single DMP model is combined with the couple pedestrian DPM to solve the pedestrian detection problem because of the pedestrian visual occlusion under common traffic models.This method extracts DPM feature through dataset such as INRIA,ETH,and then obtains the single/couple DPM model through LatentSVM training method.Moreover,the traffic pedestrian.distribution scene can be classified and divided first and then separated and remixed by the classification detention method.Firstly the target image will match with couple pedestrian template SDP-DPM.Secondly if couple pedestrian target can not be detected,the scene will be classified as single distribution,and then matching template will switch to single pedestrian template,the results will be saved.Thirdly when the couple pedestrian are detected,the distribution will be classified and mixed,and then corresponding couple pedestrian filtering response can be saved.Finally the second matching will launch with single pedestrian template,weighted sum of the two detection results.The test proved that the method stated above can efficiently detect pedestrians under scenes that pedestrian heavily cover each other,and this method also can be more accurately compared with the traditional DPM method and other popular detection methods.关键词：pedestrian detection;DPM;occlusion;traffic scene237|490|10更新时间：2025-07-16
- 摘要：Combining conventional theory with non-Archimedean theory,we study the properties of T-functions.We focus on the criteria of single cycle T-functions and entropy preservability of the most significant bit output sequence generated by T-functions.Utilizing the parameters,the connection between criteria of single cycle T-functions in two different theories is established.The situation each criterion is suited for is cleared.On the other hand,we define the notion of entropy preservability of T-functions.We talk about the entropy preservability of most significant bit output sequences generated by T-functions with uniform differentiability.We present the condition for entropy preservability of most significant bit output sequences and show the transitivity.关键词：T-functions;uniform differentiability;parameter;entropy preservability186|396|0更新时间：2025-07-16
- 摘要：Network applications in Software-Defined Network (SDN) are always required to implement several functions to meet the network service demands,but how to arrange the function modules running on SDN controller to achieve multiple function packet processing is a problem to be solved.To compose the network functions,we introduced parallel and sequential composition schemes based on multiple tables;secondly,we put forward functional composition algorithms that can adapt with any multiple-table openflow switches;finally,we devised and implemented a Ryu-based control module which is used to do the function composition.Experimental results show that the method can reduce the storage cost and processing delay effectively compared with the existing schemes.关键词：software-defined network;multiple tables;function composition;Ryu controller526|1181|2更新时间：2025-07-16
- 摘要：In the existing rule-based performance optimization approaches at software architecture (SA) level,it has not been fully concerned that the count and the order of each rule usage are uncertain in the optimization process.As a result,the search space for performance improvement is limited and the better solutions are hard to find.Aiming to this problem and taking the system response time minimum as the optimization objective,firstly,a model called RPOM is defined to abstract rule-based software performance optimization at SA level as the mathematical problem for solving the optimal rule sequence.Secondly,a framework named RSEF is designed to support the execution of a rule sequence.Furthermore,an evolutionary algorithm named EA4PO is proposed to find the optimal performance improvement solution by introducing statistical learning,constraint checking and repairing.Finally,a web application is taken as a case in the experiments for comparing with the existing methods.The experimental results indicate that the shorter system response time can be obtained and the statistical learning can obviously improve the convergence rate and the solution quality in our approach.关键词：performance evaluation;performance optimization;software architecture;search-based software engineering286|396|1更新时间：2025-07-16
- 摘要：A modeling method based on hierarchical Bayesian networks (HBN) which can be used in the susceptibility assessment of electronic system interfered by electromagnetic pulse (EMP) is proposed.According to the hierarchical structure of the electronic system and the feature of its EMP effects,steps to assess the system susceptibility are discussed.Analyzing the couple path by using the interaction sequence diagram (ISD),and the proper volume nodes of the base level of the ISD and the probability distribution of the electromagnetic stress in these nodes are determined.The topology relationship between the HBN and ISD is created by adding the directed arc from the base proper volume nodes of the ISD to the root nodes of HBN.The base proper volume level is considered as new root level to rebuild the HBN of system which can be used as the susceptibility assessment model of electronic system interfered by EMP.A case study demonstrates the effectiveness of the proposed methodology.关键词：electromagnetic pulse(EMP);susceptibility;vulnerability;reliability;electronic system;hierarchical Bayesian networks;assessment model167|1712|10更新时间：2025-07-16
- 摘要：To overcome the drawback that nodes in Named Data Networking are insensitive to the change of the content popularity,a dynamic content popularity based cache management strategy is proposed.The strategy divides the cache into primary and secondary one.The former is used to identify popular content and the latter is used to protect it.Standard Bloom Filter is adopted by the strategy to filter popular content requests.The strategy also introduces sliding window and hash table to analyze the content of secondary cache in fine granularity and manage the cache content.Simulation results show that,compared with traditional strategies,our algorithm prolongs the cache residence time of high popularity content,increases cache hit ratio and reduces server loads.Our algorithm is also scalable and has the ability to process packets at 40Gbit/s.关键词：named data networking;dynamical content popularity;line speed;content management210|482|1更新时间：2025-07-16
- 摘要：Implicit authentication mechanism plays an important and unique role in addressing the collision between security and usability on intelligent mobile device.However,most of current studies are usually built on a single feature or action,while suitable for a particular action and scenes.To solve this problem,we proposed a multi-feature fusion based on implicit authentication scheme,which uses the unique feature,such as the location,environment,posture,gait,biometric and behavioral,during use device.In the scheme,the data,such as sensors,biological and behavioral data,are collected,multi-features are trained and extracted by using the support vector machine.Then,the multi-feature fusion model is designed,and the framework of implicit authentication is constructed for calculating the user confidence level.At last,personalized security policy is designed,and the scheme authenticates user continuously and transparently.Experimental results validate the effectiveness of the proposed scheme and balance the security and usability and energy consumption.关键词：implicit authentication;multi-feature fusion;intelligent mobile device;support vector machine90|800|3更新时间：2025-07-16
- 摘要：Algorithm based on the backward recurrence for computing the integer order Bessel functions of the first kind is stable and efficient.However,the orders of the starting points should be high enough and the normalization is required.In this paper,we introduce an algorithm based on the Taylor series expansion (TSE),in which all the quantities involved are expressed in the exponential format so as to expand the numeric range of calculation.Comparison against du Toit's algorithm as well as MATLAB and Mathematica shows that our algorithm is stable and reliable.关键词：Bessel function;Taylor series expansion;exponential scaling109|312|0更新时间：2025-07-16
- 摘要：In the process of data fusion with evidence theory,precise belief structures required in original evidence theory are not always available.At this point,approaches for combination of interval-valued belief structures is needed.Existing approaches in DST and DSmT framework are reviewed,examined and analyzed.The paper proposed four version of CDI (Distribution Conflict of Interval-valued belief structures) for combination of evidence.CDI1~CDI4 are all fit for DST and DSmT framework.The approaches can deal with imprecise and uncertain information.The accuracy of combination result from CDI1~4 improves gradually.Numerical examples and comparison of results of existing approaches for interval-valued belief structure are provided throughout the paper.关键词：interval-valued belief structures;Dezert-Smarandache theory(DSmT);rules of evidence combination83|308|1更新时间：2025-07-16
- 摘要：In this paper,we first analyze the unequal impacts of various cover bits on the quality of decoded speech for parameter codecs,and further design a ranking scheme for available cover bits to utilize the cover fully.Moreover,we present an adaptive VoIP steganography based upon the performance ranking of cover bits,which can adaptively choose the optimal steganographic positions to enhance the imperceptibility of covert communications.The proposed methods are evaluated and tested with a large number of speech samples as the cover.The experimental results show that the proposed ranking scheme is sound and feasible,and the presented steganogaphic method also outperforms the existing ones.关键词：steganography;voice over IP(VoIP);information hiding;performance ranking201|333|5更新时间：2025-07-16
- 摘要：Logic Petri nets are the abstraction and extension of the Petri nets with inhibitor arcs and high level Petri nets,and can describe the Business Logic among activities concisely and accurately in process mining.To further improve the simplicity and fitness of the mining models of complex systems,especially the systems with the complex AND-OR relation in parallel activities,a method of process mining is proposed based on Logic Petri nets to improve Petri net models in this paper.An algorithm of mining logic transitions is presented to transform the business logic among activities in event logs into logic expressions adequately.Experiment results illustrate that the mining logic Petri nets can represent the event logs more properly and succinctly than the corresponding Petri nets.关键词：process mining;Petri net;logic Petri net;logic transition;mining algorithm186|459|3更新时间：2025-07-16
- 摘要：Most algorithms are based on policy evaluation in reinforcement learning.The Gaussian process temporal difference is an algorithm that uses Bayesian solution to evaluate value functions.In the method,Gaussian process builds a probabilistic generative model between the immediate reward and the value function through Bellman Equation and Bayesian rule.In order to improve the efficiency of the algorithm,approximate linear approximation for new samples is solved by on-line kernel sparse and least squares in state space.However,the time complexity is still high.To deal with this problem,a Bayesian temporal difference algorithm bases on random projection algorithm is proposed.The elements in dictionary state set are mapped to hash values by hash function.According to the hash values,groups are divided and the comparison between the states is reduced.The experimental results show that this algorithm not only improves the execution speed,but also obtains balance between execution time and precision of the state value function.关键词：reinforcement learning;markov decision process;gaussian process;random projection;temporal difference learning245|1343|0更新时间：2025-07-16
- 摘要：The bandwidth limitation in wideband audio communication systems degrades the subjective quality and naturalness of the reproduced signals.In this paper,a wideband to super-wideband audio bandwidth extension method was proposed by using echo state network.The echo state network is adopted to model the mapping function between the low-and high-frequency spectral coefficients of audio signals,and the temporal evolution of audio features is represented by continuously state updating on the basis of the recursive structure in the network,for effectively estimating the high-frequency spectral envelope.By combining the high-frequency fine spectrum extended by spectral translation,the proposed method can effectively extend the bandwidth of wideband audio to super-wideband.Evaluation results show that the proposed method upgrades the auditory quality of wideband audio,and gains better extension performance than the Gaussian mixture model-based bandwidth extension method in terms of both static and dynamic distortions for most test data.关键词：audio coding;audio bandwidth extension;echo state network;spectral translation166|399|0更新时间：2025-07-16
- 摘要：The classical method based on artificial noise for physical layer security cannot enhance the reliability of the legitimate user.Aiming at this problem,this paper proposes a dynamic method to generate artificial noise and glean benefit from the artificial noise for the legitimate user.The main idea is that the sender pre-generates artificial noise,then analyzing the interference of the noise to the legitimate user,the sender change the phase of received artificial noise of the legal user to align the noise and the desired signal.Analytical and simulation results show that the method proposed significantly improves the performance of legal users when the eavesdropper reached the same level of interference in both methods.关键词：physical layer security;dynamic artificial noise;signal alignment141|439|1更新时间：2025-07-16
- 摘要：In the context of distributed estimation in wireless sensor networks (WSN),due to transmission power/bandwidth constrains,it is significant to reduce size of transmitted data.In this paper,a distributed estimation scheme,namely,multi-level quantization scheme (MQS) is proposed.The quantization threshold optimization problem is formulated by using asymptotic performance as an optimality criterion.The optimum quantization thresholds are obtained by resorting to particle swarm optimization algorithm.The explicit expression of the Cramér-Rao lower bound is derived.The proposed method is compared with uniform quantization scheme (UQS) and no quantization scheme (NQS).Theoretical analysis and simulation results demonstrate that the MQS scheme outperforms the UQS.Moreover,with 3-bit quantization,the MQS can provide estimation performance very close to that of the NQS.关键词：Wireless sensor networks;multi-level quantization;distributed estimation;particle swarm optimization algorithm175|879|2更新时间：2025-07-16
- 摘要：With the rise of computational social science,analyzing social sentiment with data mining methods has attracted widespread attention and has become a hot spot in recent years.Existing researches of sentiment analysis mainly focus on modern text,but hardly involve the ancient short text literature.This paper proposes a short text feature extension based transfer learning model CATL-PCO(Correlation Analysis Transfer Learning-Probability Co-occurrence).Through sentiments analysis in ancient literature,this paper can discovery social and cultural development in the ancient era.CATL-PCO expands the ancient literature feature vector based on the frequent word pairs,and utilizes transfer learning method to train three sentiment classifiers.CATL-PCO solves the problem of sparsity of short text feature vector,and the scarcity of modern translation,which improves the cognition of Chinese History.Experiments demonstrate the effectiveness of the proposed method on the dataset of Chinese poems in Tang Dynasty.Moreover,different periods of Tang and Song Dynasty,and different genres are analyzed in this paper in details.关键词：sentiment analysis;computational social science;poetries of the Tang dynasty and Song dynasty;transfer learning241|1021|7更新时间：2025-07-16
- 摘要：Authentication builds the trust relationship between communication parties,which is a magnitude guarantee for secure communications.However,existing protocol testing techniques focus on validating the protocol specification.Those techniques can not satisfy the requirements of testing protocol authentication as their lack of the method for describing security properties.Therefore,a protocol security property testing method is proposed for testing protocol authentication.This testing method uses a new formal model-Symbolic Parameterized Goal Extended Finite State Machine (SPG-EFSM) for describing protocols and their security properties.Then,a protocol attack algorithm is designed for testing protocol authentication based on different attack scenarios.Through test experiments on the well-known protocol Woo-lam and μ TESLA,it is found that the SPG-EFSM based attack algorithm can find several protocol security flaws and has better feasibility and high coverage.关键词：protocol testing;security properties;authentication testing;formal model;attack classification92|398|0更新时间：2025-07-16
- 摘要：Space-time adaptive processing (STAP) needs to estimate clutter covariance matrix by training sample data.However,this estimation is always corrupted by outliers,which even lead to target self-nulling phenomenon.Hence,a novel robust STAP algorithm based on joint sparse recovery of clutter spectrum is proposed,which can eliminate the influence of outlier.This algorithm is applied in side-looking airborne radar.When the sparse recovery is high resolution,the algorithm exploits the characteristic that distribution and correlation between clutter and outlier are different among multiple snapshots.The norm is employed to select the most suitable sparse recovery coefficients to estimate the clutter spectrum,so outlier can be eliminated effectively.Monte Carlo experiments prove that the proposed algorithm has advantages in robustness and target detection over other conventional STAP algorithms in non-homogeneous clutter environments.关键词：airborne radar;space-time adaptive processing;sparse recovery;outlier110|356|6更新时间：2025-07-16
- 摘要：A method for blind classification of Space-Time Block Codes (STBCs) with a single receive antenna based on elementary fourth-order cumulants is proposed. Firstly,the theoretical values and variance of various signal constellations were obtained by computing the ensemble averages over the ideal noise-free constellation. And then the thresholds were gained by the likelihood ratio test (LRT) for the tests in the hierachical classification scheme. Finally,the automatic classification of modulation scheme was realized by comparing the experimental values and the thresholds. Furthermore,unlike other methods,this algorithm does not require any prior information of the channel coefficients,and noise power and,consequently,is well-suited for non-cooperative context. The simulation shows that the proposed algorithm performs well even at a low signal to noise ratio (SNR).关键词：space-time block codes (STBCs);modulation classification;single receiver antenna;elementary fourth-order cumulants132|323|2更新时间：2025-07-16
- 摘要：A Method for Construction self-dual codes over Z4 is proposed by using self-dual codes over the ring Z4+vZ4,where v2=1.A Gray map from (Z4+vZ4)n to Z42n is introduced,and some properties about self-dual codes over Z4+vZ4 are given.It showns that the Gray image of a self-dual code over Z4+vZ4 of length n is a self-dual code over Z4 of length 2n.Further,some extremal Type I and Type Ⅱ codes over Z4 are constructed.关键词：gray map;linear codes;self-dual codes127|391|0更新时间：2025-07-16
- 摘要：In order to decrease the high tracking precision press of free space optical communication,simplify the optical antenna structure and reduce the system size,a new specialized micro-channel plate-photomultiplier tube(MCP-PMT) using complex waveguide anode is first proposed in this paper,which could be used in free space optical communication system (FSO).First of all,from the view point of photomultiplier model of microchannel plate,the principle of new device is described and the effect of both transmission and position anode of complex waveguide anode to constraints of vacuum photomultiplier system is analyzed; Secondary,the device characteristic of the complex waveguide anode devices is investigated through analytical method of modulation transfer function(MTF),and the corresponding relations between design parameters of device and imaging ability is given.Based on the above,constraint relation between high-speed signal detection and optical axis position are investigated and corresponding design and correction method of electro-optical system are derived.At last,this kind of new device is verified through experiment in the vacuum furnace.关键词：free space optical (FSO);micro-channel plate-photomultiplier tube(MCP-PMT);complex waveguide anode112|372|7更新时间：2025-07-16
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0