最新刊期
卷 43 ， 期 4 ， 2015
- 摘要：A bidding method for collaborative decision-making is addressed for social network service (SNS).It consists of three phases as:in first bidding content organizing phase,formal semantic is proposed to express and organize the contents of decision-making tenders from publishers;in strategy selection phase,capacity evaluation based selection scheme is presented to find optimal bidding parties.Meanwhile,a trust computation method,named DecTrust,is presented to evaluate the trustworthiness of bidding parties;finally,in bidding process controlling phase,the patterns of invited tendering and bidding negotiation are proposed.Simulation results show the methodology is feasible and effective.关键词：social network service;semantic;collaborative decision-making;capacity evaluation;trust;bidding pattern2|2|0更新时间：2025-07-16
- 摘要：Application mapping is one of the key issues in MPSoC design.For MPSoC systems running multiple applications,a memory-aware and user-aware application mapping strategy is proposed.This strategy classifies the applications into hot applications which access large amounts of data and non-hot applications with moderate memory access by offline analysis.Then,the applications are further identified as critical or non-critical application with respect to the user behavior at runtime.For each application,different mapping algorithm is applied according to the above classification.Hot applications are distributed as close as possible to the shared memory.The internal communication cost and contents are minimized for critical applications,and the external communication cost and contents are minimized for non-critical applications.Experimental results show that the proposed strategy saves the overall system communication energy,compared with the single memory-aware or user-aware strategy.关键词：MPSoC(multiprocessor system-on-chip);NoC(network-on-chip);application mapping;task mapping2|2|3更新时间：2025-07-16
- 摘要：The stream processing systems,whether centralized or distributed,have to overcome the single-node bottleneck.Moreover,their static configurations also make them either shortage or surplus of resources.To this end,this paper proposes a scalable parallel-distributed stream processing system named SPSPS.The system splits a query into parallel sub-queries according to stateful query operators to minimize the communication overhead in parallel processing,and achieves order-preserving tuple processing through the stateful operator's distributor and collector.Moreover,the scalability techniques with load balancing and reconfiguration support effective adjustment of resources depending on the incoming load.The experiments on a cluster with 60 nodes prove the scalability.关键词：stream processing system;scalability;stateful operator;load balancing;reconfiguration2|2|3更新时间：2025-07-16
- 摘要：This paper presents a context-sensitive and path-sensitive algorithm for detecting null pointer dereferences (NPD).Our algorithm tracks the flow of values from the points where a null pointer might be produced to dereference points via value dependence graph that captures def-use relations and combines interval analysis results.Edges in the graph are annotated with guards that describe branch conditions in the program.In the meantime,for reducing the false warnings we propose an innovative demand-driven must-alias algorithm using this graph.Our implemented tool detects more than 70 points which might produce null pointer dereferences in ten SPEC 2000 benchmarks while keeping the false positive rate around 6%,which is excellent experimental results.关键词：program analysis;static error detection;null pointer dereference detection;demand-driven alias analysis2|2|3更新时间：2025-07-16
- 摘要：Based on the analysis of multi-dimension Bloom filter presented before,an accurate multi-dimension counting Bloom filter(AMD-CBF) query algorithm based on bijective function is proposed for big data processing.When representing or querying an element,AMD-CBF needs two steps.The first step is to hash and map each attribute of the element to their corresponding accurate counting Bloom filter (A-CBF);The second step is to transform all attributes of the element into a value by bijective function to represent the overall information of the element,then the value is hashed and mapped into a combined counting Bloom filter (C-CBF)for completing the representation and query confirmation of the elements overall.Both theoretical analysis and experiment show that the AMD-CBF can support concise representation,approximate membership query and deletion of multi-dimension data set and significantly lower false positive rate and improve query accuracy compared to similar research.关键词：big data processing;multi-dimension Bloom filter;bijective function;accurate counting Bloom filter;false positive2|2|5更新时间：2025-07-16
- 摘要：In order to overcome the shortcoming of the efficiency of the Ito algorithm for the discrete combinatorial optimization problems,an improved Ito algorithm based on collaborative diffusion coefficient and Hill climbing was proposed in this paper.To be consistent with the principle of Brownian motion,the drift and wave should be moved simultaneously,when it found a feasible solution,which continued to be a degree of renewed volatility.Experimental results show that the improved Ito algorithm for solving vehicle routing problem with a soft time window is valid,with the convergence speed,robustness and stability,especially Ito algorithm combines the ability of local search algorithms after climbing method performance has been greatly improved.Finally,according the nature of Markov chain to move to its attractive element and the transformation of the relationship between each state,the Markov chain approximation simulation algorithm which structures the Ito stochastic differential equation and its convergence was proved in this paper.关键词：Ito algorithms;drift operator;wave operator;convergence analysis;vehicle routing problem with soft time windows2|2|5更新时间：2025-07-16
- 摘要：In this paper,a method based on a simplified virtual-force model is proposed for swarm robots hunting in unknown non-convex,convex and dynamic obstacles environments.First,the motion models for the hunting target and dynamic obstacles are presented.Then through the decomposition of hunting behaviors under complicated environments,a simplified virtual-force model is formed.Based on the model,the control method is designed for swarm robots following motions of barriers and the hunting target;the stability of the hunting system is analyzed and the control parameter ranges are given.Simulation results demonstrate that the proposed method can maintain a good hunting formation and has good performance of obstacles avoidance and flexibility.Finally,advantages of this method are presented,compared with the hunting method based on loose preference rule.关键词：mobile robots;swarm robots;non-convex obstacles;simplified virtual-force model;collision avoidance;formation keeping2|2|4更新时间：2025-07-16
- 摘要：Along with the ever-growing Web,specified sensitive videos including horror videos and violent videos are disseminated over Internet and have threatened children's psychological health.It is necessary to effectively recognize and filter out these videos.So far,the existing recognition methods for specified sensitive videos either ignore the multiple contextual information among the shots,or ignore the dependent relationship among the multiple features.This paper presents a novel recognition method for specified sensitive video based on multi-context construction and linear fusion.First,multiple effective features are extracted and the multiple contextual structure graphs are constructed for the shots in one video clip.Then,a SVM classifier is trained using contextual information in each feature space.Finally,a linear dependency model is learnt to fuse multiple classifiers obtained in different feature spaces.Experiments on a specified sensitive video dataset demonstrate that the performance of our method is superior to the other existing algorithms.关键词：specified sensitive video;multi-context construction;classification fusion;linear dependency model2|2|2更新时间：2025-07-16
- 摘要：Using single feature of images to describe the image content is one-sided because of insufficient information.To solve this problem,combing SIFT and KDES-G features to describe images is proposed by generating a joint vector as a new feature vector.Considering images' spatial information,an image classification method based on the spatial visual dictionary is proposed.Images are first divided into sub-regions according to spatial pyramid,and the spatial visual dictionaries are respectively constructed by grouping features of each region into a number of clusters.The features of each region are coded by LLC based on its corresponding dictionary,and then the coded feature vectors are given different weights according to the different contribution of each region.After that,the feature vectors of different regions are concatenated and regarded as the final image description.Finally,a linear SVM is used to classify images.Experimental results show that the proposed method has better performance and robustness compared with some state-of-the-art works.关键词：image classification;feature fusion;spatial visual dictionary;local constrained linear coding ( LLC);weighted processing2|2|7更新时间：2025-07-16
- 摘要：In order to analyze the application effect of spectral analysis techniques in different scenes and provide an optimal one for forest applications,numberical simulations and multi-baseline interferometric synthetic aperture radar(InSAR) data in forest scenario were used to analyze the extraction result using five spectral analysis techniques.It is discovered that,signal to noise ratio (SNR) has little effect on Capon method,and has greater impact on weighted noise subspace fitting estimator (NSF),multiple signal classification (MUSIC) and weighted signal subspace fitting estimator (SSF) method.In tomographic SAR (TSAR) experiment,Capon method has best result in forest canopy/vertical structure information extraction.NSF method has best result in canopy height and topographic information extraction followed by MUSIC.This experiment provided a reference for spectral analysis technique choice in forest information extraction using multi-baseline TSAR.关键词：SAR;tomographic SAR (TSAR);beamforming;Capon;multiple signal classification (MUSIC);weighted signal subspace fitting estimator (SSF);weighted noise subspace fitting estimator (NSF);forest vertical structure4|4|2更新时间：2025-07-16
- 摘要：There are power frequency interference and other kinds of noise in the electro encephalo gram (EEG)signal acquisition process.They make the signal show non-stationary and a variety of multi-form waveform in the instantaneous structure.Then such signal will affect the normal processing of the speech in DIVA(Directions Into Velocities of Articulators) model.Therefore,this paper proposes an adaptive sparse decomposition model for the feature extraction of EEG signal structure and makes use of Matching Pursuit algorithm to solve the optimal atom.Then the original EEG signal can be represented by atoms in the complete atomic library.Finally,this model removes noise that exists in the EEG signal and is compared with wavelet transform method.Simulation results show that after we put the denoising EEG signal into the model,the phonetic pronunciation improves.关键词：directions into velocities of articulators (DIVA) model;electro encephalo gram (EEG) signal;noise;sparse decomposition3|2|2更新时间：2025-07-16
- 摘要：The traditional Sparse Recovery (SR) algorithms are unsuitable for signal reconstruction of Multiple Measurement Vectors (MMV) for the following two reasons,one is the high computing burden,and the other is that the presented algorithms are not used to the case when MMV are arbitrary sparse structure.To solve the problems,a novel fast sparse recovery algorithm is proposed.Firstly,the Matrix Smoothed L0-norm (MSL0) algorithm is adopted to reconstruct the MMV of arbitrary sparse structure and estimate the initial support.Secondly,using the relationship between the sparse level and measurement number,the pre-selection support is obtained from choosing the initial support.Thirdly,the final support is gotten with Bayesian Group Testing (BGT) method.And finally,the MMV is reconstructed precisely via the final support.The proposed algorithm makes full use of high efficiency of the MSL0 and redundancy support elimination ability of the BGT.The algorithm can not only reconstruct MMV of arbitrary sparse structure more efficiently,but also has higher reconstructed accuracy and better robustness.ISAR imaging experiments based on real data show the validity of the proposed algorithm.关键词：sparse recovery;arbitrary sparse structure;multiple measurement vectors;Bayesian group testing;matrix smoothed L0-norm3|2|12更新时间：2025-07-16
- 摘要：Clutter background suppression is always a difficulty of infrared (IR) dim and point target detection.Background suppression is divided into background estimation and difference filtering.Aiming at the nonlinear distribution of strong clutter background,a spares kernel recursive least squares (KRLS) based nonlinear background suppression algorithm is proposed.This method uses sequence images as training sample in supervised learning model.The complexity of learned function is controlled,and the redundant information is discarded by sparsification.In this way,the generalization of learning machine can be enhanced;moreover,the computational burden can be reduced.In the experiments,real IR images are used to test the algorithm,and the parameters are analyzed.Experimental results show that different kinds of strong clutter background can be estimated,and then be suppressed.关键词：IR background suppression;strong clutter;background estimation;sparse;kernel recursive least squares2|3|2更新时间：2025-07-16
- 摘要：In order to avoid the iterative computations in passive location,two theoretical analysis frameworks used to solve two kinds of location equations are presented via converting the nonlinear measurement equations into the pseudo-linear equalities.First,two kinds of mathematical model for the pseudo-linearization of two nonlinear measurement equations are formulated,which are not limited to specific physical measurements,and then the corresponding weighted linear least squares (WLS) solutions are derived.Subsequently,the theoretical estimation variances of the two analytical solutions are derived through first-order perturbation analysis methodology,and their theoretical location performances are proved to be able to attain the corresponding Cramér-Rao bound (CRB) before the threshold effect occurs and,hence,the asymptotical optimality of the two pseudo-linearization location methods are verified.Finally,the AOA/TOA location and AOA/TDOA/FDOA location are taken as examples to describe the application of the two pseudo-linearization location methods,and the simulation experiments are conducted to corroborate the effectiveness of the theoretical analysis in this paper.4|2|4更新时间：2025-07-16
- 摘要：In the paper,we propose a new design of unitary space-time constellations which is generated based on a combination of permutation method and rotation method.This method can provide better performance for the unitary space-time constellation signal.At the same time,for this joint constellation,a new classification demodulation algorithm is given.This algorithm can recognize the class of transmission signal with very low error probability and reduce the research range under the maximum-likelihood algorithm,so both the error performance and the complexity of constellations can be improved.Theoretical analysis and simulation results all show that the performances of proposed constellations are better than some other constellations which are designed by only one method while the complexity of demodulation is reduced greatly.关键词：unitary space-time constellation;permutation method;rotation method;joint;class2|2|0更新时间：2025-07-16
- 摘要：In order to reduce the hardware complexity and the delay of high-order SVD processor,two improved CORDIC modules including Arc Tan and Rotation functions are designed.These two improved CORDIC modules have better performance in terms of register saving and real-time quality.In this paper,a 2×2SVD module using above-mentioned CORDIC modules with 19bit data width has implemented on XilinxVirtex6 and the throughout reaches 25.9Gbps.Compared with the 2x2SVD module using IP core,it reduced 27.6% registers,27.7% LUTs and improved 14% real-time performance.Moreover,the trend curves of hardware consumption are presented which have testified that these two improved CORDIC modules can reduce 40% hardware complexity of 16-order SVD processor.关键词：singular value decomposition(SVD);coordinate rotation digital computer(CORDIC);vector rotation2|2|1更新时间：2025-07-16
- 摘要：In wireless sensor networks (WSNs),node replication attacks and Sybil attacks can disrupt the network's operations such as data aggregation and threshold voting schemes.To launch these attacks,it is necessary to go through the neighbor discovery verification process firstly,which is not frequent in WSNs.Considering the above observations,a one-way key chain ID authentication (OKCIDA) defense mechanism was presented to decrease the probability for attackers to mount such attacks at any time.Moreover,the symmetric parameters was constructed based on the elliptic curve discrete logarithm problem;then combines with OKCIDA and utilizes node neighbor relationship,a location-free neighborhood authentication protocol (LFNA) was introduced to stop replica nodes and Sybil nodes from successfully joining into the network.Finally,the security of LFNA was proved and analyzed.Compared with several existing important mechanisms,the proposed method is superior in security and cost.关键词：wireless sensor network;node replication attack;Sybil attack;authentication;one-way key chain3|3|2更新时间：2025-07-16
- 摘要：In order to analyze the security and universality of the arithmetic proposed by Sheng et al,the concept of information loss in single iteration and average speed of information loss in dynamic system is proposed based on information theory.It is shown that the information loss of the 2nd bit-operation transformation is 12 bits,and which of the standard 2nd bit-operation transformation is related to the exponent e.It is possible that the information loss of the 2nd bit-operation transformation is so small.Not all of the float number in[-1,1]can be traversed by the standard 2nd bit-operation transformation just because the 1023-e is used as the shift number.The concept of transient data and 1st transient transformation is proposed further,and the arithmetic proposed in literature[14]is improved as well.The output sequence of random digital chaotic system can be transformed as float number in[0,1]by the improved arithmetic.The information loss of this transformation is L-1 bits,which is approached to the maximum speed of information loss Imax=L under the computing precision L.The transformed sequence is uniform distributed which can be proved by χ-verification.关键词：digital chaotic;uniformity;transient data;transient transformation2|2|0更新时间：2025-07-16
- 摘要：To solve the multi-receiver time-dependent ciphertext retrieval problem efficiently,by borrowing the technique of identity-based broadcast encryption,we propose a cryptosystem of one to many public key timed-release searchableencryption (PKTRSEOM).In our PKTRSEOM model,the sender transmits anencrypted message to cloud server so that only the intended authorized user group member can search the target ciphertext containing specified keywords,but cannot decrypt it until the release time in the future.We formalize the notion of PKTRSEOM and its security game model.Then,we construct two provably secure PKTRSEOM schemes which are secure under the q-DBDHI assumption and give the rigorous proof for both schemes.The efficiency analysis shows that the two schemes achieve constant costs from the sender's and the recipient's points of view in the running process of the system and the second scheme is more efficient than the relevant schemes.关键词：timed-release;searchable encryption;one-to-many;provable security3|3|3更新时间：2025-07-16
- 摘要：The reliability analysis for the magnetic head includes solders joint early drops splash protection and solders joint post failure analysis.In actual production,applying the jetting solder ball bonding (SBB) technology,solder splash have occurred frequently.Combining the laser heating and nitrogen pressure technology,this thesis aimed at building a new double of droplet model for calculating the striking velocity of the solder which is used to connect the Built-DFH in Slider,while different parameters of the laser heating and the nitrogen pressure are compared through the orthogonal test.The controllable scanning magnetic fields and bias are further incorporated and the failure of magnetic solder joint is studied.The results showed that before the solder falls,laser energy is the most important factor affecting the solder splash.After the solder falls,we find that the temperature of the melting ball has no decrease during the fall.The temperature of the impinging melting ball depends on its initial value.The failure of magnetic solder joint is caused by solder droplet splash and intermetallic compounds.关键词：solder splash;nitrogen pressure;dynamic flying height;double droplet model2|2|0更新时间：2025-07-16
- 摘要：The sparsity and group sparsity have important applications in the statistics,signal processing and machine learning.This paper summarized and analyzed the differences and relations between various group sparse models.In addition,we compared different models' variable selection ability,variable group selection ability,variable selection consistency and variable group selection consistency.We also summarized the algorithms of group sparse models and pointed the advantages and disadvantages of the algorithms.Finally,we point out the future research directions of the group sparse models.关键词：sparsity;group sparsity;variable selection;variable group selection;consistency2|2|4更新时间：2025-07-16
- 摘要：Spectral capture technique collects information with more color channels than traditional trichromatic sensing.Therefore it provides more detailed properties of the light source and the scene.Possible applications span across lots of fields such as remote sensing,materials science,bio-photonics,environmental monitoring,computer vision and so on.Spectral capture technique needs to record massive data in spatial,temporal and spectral dimension,whereas traditional spectral capture systems suffer from temporal and spatial scanning which is not suitable for video capture.Nowadays,with rapid development in sampling theory and electronic techniques,spectral video acquisition is becoming feasible.This paper presents a review and comparisons on the capturing techniques of high resolution spectral video,especially on hyperspectral video capturing research.In the end,relative applications and future work of hyperspectral video capture are also discussed.关键词：hyperspectral;video capture;resolution3|3|5更新时间：2025-07-16
- 摘要：In this paper,a scheme of cooperative jamming with optimal relay selection and power allocation is proposed.The proposed scheme selects one node from the intermediate nodes as relay and the rest nodes as friendly jammers.The relay operates in amplify-and-forward (AF) strategy.Jammer weights are derived to null the jamming signals at the destination and relay node and maximize the jamming signal at the eavesdropper.Furthermore,a closed-form optimal solution of power allocation between the selected relay and cooperative jammers is derived.Numerical simulation results show that the proposed scheme can outperform the conventional schemes at the same power consumption.关键词：physical layer security;relay selection;cooperative jamming;power allocation4|3|5更新时间：2025-07-16
- 摘要：Feature selection as a substantial preprocess step is a key factor for improvement of classification accuracy.The network traffic is characterized by huge volume and high dimensions.So how to extract the optimal feature subset in short time is practical for traffic classification based on machine learning.A novel method is proposed,which partitions the traffic dataset into several small subsets,and applies special feature selection algorithm to them respectively.Finally,the optimal feature subset is obtained by voting on these alternative feature subsets.The experiment results show that the proposed method has good time efficiency in searching optimal features and helps to improve classification accuracy efficiently.关键词：divide and conquer;voting;traffic classification;feature selection2|2|6更新时间：2025-07-16
- 摘要：The degree distribution has a very important influence on the decoding efficiency of fountain codes.The decoding performance is good when the message size is large,but it drops dramatically when the size becomes smaller,which is the inevitable result of using the existing degree distributions to encode.In this paper,we present a new scheme to design the degree distribution.First,we combine the robust soliton degree distribution with the modified binary exponential distribution and further adjust the degree by optimizing the ripple size.By doing this we can get modified binary robust distribution(MBRD),which can also perform well when the source message size is small.Through simulation experiments,we have verified that MBRD greatly improves the encoding and decoding performances.Moreover,compared with the existing degree distributions,the smaller the source message size becomes,the more evidently the performance is improved.关键词：fountain codes;LT codes;degree distribution;ripple size2|2|6更新时间：2025-07-16
- 摘要：Randomly distributed sensor nodes in the sensor network may receive weak signals.Signal combining technology can be used to enhance the performance of signal perception for the sensor network system.This paper focuses on the combining weight estimation for weak signal combining for the wireless sensor network.Taking the combined signal autocorrelation coefficient as the object function,this paper proposes an eigen value decomposition-based combining weight estimation algorithm.The algorithm does not require to estimate the noise correlation matrix,and can be applied to the non-uniform noise variance environment.The numerical simulation results show that the proposed algorithm outperforms classical eigen-based algorithm using the combined signal SNR or power as the object function,under low SNR environment with non-uniform noise variance for weak sensor nodes signal combining.关键词：wireless sensor network;signal combining;eigenvalue decomposition;autocorrelation coefficient2|2|1更新时间：2025-07-16
- 摘要：The periodicity is a feature of science and engineering phenomena,so detecting periodicity from complex and noise-included samples and measuring its parameters are important topics in signal processing.Spectral correlation is a useful tool to find second-order periodicity of cyclostationary signals.This paper investigates the reasons,procedures and features using spectral correlation to analyze cyclicity.First,internal relations between main definitions in spectral correlation theory are summarized and mathematic diagrams reflecting their transforming or mapping relations are built.Then a method to calculate spectral correlation based on the diagrams is proposed.By analysis of single periodic signals and connections between periods and results in each operation,physical functions of cyclic autocorrelation,spectral correlation,limit periodic spectrum and cyclic frequency,etc,are interpreted.关键词：cyclostationary signals;spectral correlation;cyclic autocorrelation;second-order periodicity;Wigner-Ville distribution3|3|7更新时间：2025-07-16
- 摘要：The bandwidth limitation of wideband audio degrades the subjective quality and the naturalness.In this paper,a bandwidth extension of audio signals from wideband to super-wideband was proposed by using a similarity correlation degree-based neural network.Firstly,the fine spectrum of wideband audio was converted to a multi-dimensional phase space.Then,a similarity correlation degree-based neural network was built up to reproduce the high-frequency fine spectrum.In addition,Gaussian mixture model was used to estimate the high-frequency spectral envelope.Finally,the bandwidth was extended to super-wideband by the proposed method in the ITU-T G.722.1 wideband codec.Evaluation results indicate that the proposed method is preferred over the reference methods and achieves a comparable subjective quality with the G.722.1C super-wideband codec.关键词：audio coding;audio bandwidth extension;similarity correlation degree-based neural network;phase space reconstruction;Gaussian mixture model2|2|0更新时间：2025-07-16
- 摘要：A fast repairing algorithm is proposed especially for the bottom hollow existing in spherical virtual image (SVI).First,the mapping relationship between spherical panorama and the corresponding SVI is acquired,and the location mapping model is constructed based on the relationship of different SVIs obtained at different moments.Then,the correspondence between different spherical panoramas is solved and the missing parts are repaired.At last,through luminance adjustment and edge blending,the repairing result is optimized.Theoretical analysis and experiment results show that,through using the feature of bottom hollow's fixed location,a fast repairing algorithm is built with the complexity of O(n),which can realize the repairing of bottom hollow in SVI quickly and effectively.关键词：spherical virtual image (SVI);image repairing;location mapping model;hollow repairing2|2|0更新时间：2025-07-16
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