最新刊期
卷 42 ， 期 10 ， 2014
- 摘要：We proposed a Multi-node exact Minimum Storage Regenerating code (MMSR code) based on interference alignment which is satisfying MDS nature.First, we designed the generator matrix of the storage nodes of MMSR code by Cauchy matrix, for the purposes that using interference alignment technology and repair multi-node simultaneously.Then we discussed the advantages and disadvantages of the synchronous repair mode and asynchronous repair mode.Finally, we proved the MDS nature of MMSR code and proposed a specific data reconstruction scheme for the (7, 3, 5)-MMSR code to verify the MDS nature and feasibility of MMSR code.关键词：cloud storage;multi-node repair;interference alignment;regenerating code;Cauchy matrix2|2|5更新时间：2025-07-16
- 摘要：A confidence test method based on Kolmogorov-Smirnov hypothesis test is proposed to evaluate the blind processing results of BPSK signals.The hypothesis test model is created at first.The reference signals are constructed depending on the certain identified modulation result and the phase series are extracted from the correlation between the reference signals and the observed signals.By computing the empirical cumulative distribution function of the phase series and comparing it with the specific cumulative distribution function of phase series under null hypothesis, the K-S based confidence test is performed.Simulation results show that the proposed method can be used to verify the confidence for blind processing results of BPSK signals at low signal-to-noise ratio.关键词：blind signal processing;confidence evaluation;Kolmogorov-Smirnov hypothesis test2|2|3更新时间：2025-07-16
- 摘要：Multi-target bearing-only localization on sensor network suffers from unknown association between measurements and targets, making it difficult to achieve real-time localization, especially with the existence of bearing measurement errors.A data association method is designed for multi-target localization to deal with the unknown target initial states and complex measuring phenomena.Theoretical deduction of sensing probability and gate threshold selection is given on the basis of measurement error analysis.A data association method based on scalable gate threshold is proposed to estimate target when the measurement is importing to the data fusion center, ensuring the probability that intersection of bearing measurement is real target localization.Simulation results show that the proposed method works well under different settings and the required acceptable computation load.关键词：data association;bearing-only sensor networks;multiple-target localization;sensing probability4|2|4更新时间：2025-07-16
- 摘要：The article analyzes on task planning of early warning system of LEO under dynamic disturbances innovatively.It discusses and quantifies the dynamic disturbances, puts forward the task dynamic planning model of early warning system of LEO.And then the passage researches on the solving method of the re-planning period, sets up the re-planning models under dynamic disturbances, and the model under resource disturbance is transformed into the model under new task disturbance based on two-level optimized goal.To solve the dynamic planning models, a heuristic algorithm is designed, and a example is validated for the content.The paper provides important inspiration to the dynamic task planning problem.关键词：early warning system of LEO;dynamic disturbances;task planning;mixed re-planning;heuristic algorithm2|2|1更新时间：2025-07-16
- 摘要：Optimized iterative clipping filtering (OICF) is an optimal algorithm for peak to average power ratio (PAPR) reduction, since it can achieve the required PAPR reduction with minimum in-band distortion.However, OICF needs to solve a convex optimization problem with O(N3) complexity, where N is the number of subcarriers.To reduce the complexity, a method based on the peak cancellation (PC-PAPR) is proposed.This method uses a zero-phase filter, which length is Q, to modify the spectrum of the peak pulse.After the filter, the phase of the peak pulse is not changed, and the out-of-band spectrum of the pulse is zero.Results of analysis show that the computational complexity of the PC-PAPR is O(QN), and simulation results show that the difference of PAPR-reduction performance between PC-PAPR and OICF is less than 0.06dB.关键词：multi-carriers systems;peak to average power ratio (PAPR);iterative clipping and filtering (ICF);peak cancellation;zero-phase filter2|2|1更新时间：2025-07-16
- 摘要：To solve the problem of redundant nodes in sensor networks, this paper proposes a way to determine and turn off redundant nodes in order to lengthen the network lifecycle.This paper first classifies nodes by the different locations of the neighboring nodes, and then studies the constraint relations between coverage of neighboring nodes and working nodes k in each group.On this basis, the paper determines nodes according to different redundancy rules and turns off redundant nodes.The theoretical analysis and experimental results show that the proposed algorithm can turn off redundant nodes in the network, which in turn effectively prolongs the network's lifetime.关键词：node scheduling;heterogeneous wireless sensor networks;categorization of neighborhood nodes;distance of neighborhood nodes2|3|9更新时间：2025-07-16
- 摘要：This paper proposes a controlled quantum network coding scheme based on single controller so as to control the decoding operation at the receivers for traditional quantum network coding schemes.This scheme is designed based on the paradigm XQQ(Crossing Two Qubits) protocol, and it can control the decoding process of two receivers simultaneously by means of introducing the controller in controlled teleportation.Scheme analyses show that without the permission of the controller, any attacker cannot decode and acquire the quantum information from the senders in this scheme, even if he can get all the information of the receivers.Thus our scheme can enhance the security of transferring quantum information in quantum networks.关键词：controlled teleportation;quantum network coding;XQQ protocol;security2|3|1更新时间：2025-07-16
- 摘要：The erasure floor of LT Codes is mainly determined by the minimum degree of variable-nodes.Regular variable-node degree LT Codes can maximize the minimum degree of variable-nodes and improve the erasure floor of LT Codes.In this paper, a novel encoding scheme for regular variable-node degree LT Codes is proposed.Compared with existing methods, the proposed scheme is lightweight due to the elimination of the sorting operations involved in the look-up table.Meanwhile, by adding check nodes with low degree through modifying the degree distribution, the waterfall area (avalanche area) in decoding regular variable-node degree LT Codes is improved.Simulation results show that this scheme reduces the encoding time and the average overhead, and accelerates the convergence rate of symbol error rate curve efficiently.关键词：fountain code;regular variable-node degree LT codes;erasure floor;degree distribution2|2|3更新时间：2025-07-16
- 摘要：Sea clutter is consist of a speckle component modulated by texture.The stationary properties of speckle and texture will be researched in the paper.By using the discrete Fourier transform(DFT)modulated filter bank to decompose sea clutter into low-rate subband signals, two consistency factors are proposed to analyze the stationary properties of speckle and texture of different subband signals, respectively.The results show that the non-stationary characteristics of sea clutter is mainly reflected in texture.Texture is significantly non-stationary in the strong clutter region, and vice versa.Considered that sea clutter in different Doppler frequency has different stationary property, by using the consistency factor of texture as a judge function, a subband switching adaptive normalized matched filter(ANMF)detector is proposed in the paper, where the covariance matrix estimator is sample covariance matrix(SCM)or normalized sample covariance matrix(NSCM), respectively.The experimental results show that, to detect targets in real sea clutter, the subband switching ANMF detector outperforms competitors.关键词：radar target detection;non-stationary sea clutter;stationary measurement;consistency factor3|2|1更新时间：2025-07-16
- 摘要：Noise estimation is the basis of the adaptive blind signal detection.It provides the thresholds of automatic detector based on the CFAR (Constant False Alarm Rate) rule.The traditional noise estimator was complicated and cannot be easily implemented in the on-line blind signal processing system for the satellite broadband frequency-hopping signal.Utilizing the sparseness of the frequency-hopping signal, a new algorithm was proposed to facilitate the noise estimation.The reliability and complexity of the algorithm was analyzed theoretically, and the effectiveness was verified through both simulations and real signal experiments.Compared to the classical algorithm, the proposed algorithm can provide similar noise estimation results, while its computational complexity and buffer consumption was significantly reduced.关键词：noise estimation;frequency-hopping;satellite communication;energy estimation2|2|3更新时间：2025-07-16
- 摘要：Rate control is one of the key technologies in feedback-free distributed video coding(DVC) systems.This paper studies the fast method to generate side information at encoder, based on the error probability of each bitplane between side information and Wyner-Ziv(WZ) information, a bitplane error probability based encoder rate control (BEP_ERC) algorithm is proposed.Also the idea of calculating the Laplace-Cauchy mixture distribution (LCMD) model parameter αand μat encoder is proposed.Experimental results show that the proposed BEP-ERC method has a higher rate-distortion (RD) performance than other existing feedback-free algorithms, with the increament gap of 0.1～0.4dB.In addition, its computation complexity is lower.关键词：distributed video coding;feedback-free;rate allocation;correlation noise model2|3|2更新时间：2025-07-16
- 摘要：The end-to-end performance of a dual-hop amplify-and-forward relaying system is investigated over composite multipath-lognormal fading channels by using Mixture Gamma(MG)channel model.Novel exact closed-form expressions for the cumulative distribution function and the moment-generation function of the end-to-end signal-to-noise ratio are derived.Moreover, the average symbol error rate, outage probability and the diversity order are found based on the above new expressions, respectively.These expressions are more simple and accuracy than the ones obtained by using Generalized-K(KG)channel model.Finally, numerical and simulation results are shown to verify the accuracy of the analytical results.关键词：dual-hop relaying;composite multipath-lognormal fading;mixture Gamma;generalized-K;performance analysis2|2|1更新时间：2025-07-16
- 摘要：The information rate is an important metric of the performance of a quantum-secret-sharing scheme.In this paper, we characterize the quantum access structures by means of the theory of hypergraph.Furthermore, we derive the optimal information rate and the construction of perfect quantum-secret-sharing schemes corresponding to the quantum access structures with at most four players which are given in terms of the relationship between certain access structures and hypergraphs.The exact values for the optimal information rate in 5 of the 13 access structures are computed and the relevant construction of perfect secret sharing schemes is discussed.At the same time, the upper bounds for the information rate of other 8 quantum access structures are computed.关键词：information rate;quantum-secret-sharing scheme;quantum access structures;hypergraph;quantum entropy2|2|6更新时间：2025-07-16
- 摘要：In view of the poor time-efficiency and generality of the traditional macro cell method, an improved macro cell method(IMCM)is proposed, capable of extracting the dispersive properties of any 1D reciprocal artificial periodic transmission line(APTL)with finite periodicity.Key to the IMCM lies in that the multiple-root problem of the initially extracted phase shift constant is transferred to the problem of judging the starting frequency of the phase unwrapping, making it easy to determine the uniquely correct phase shift constant.Since the electromagnetic coupling effects among unit cells of a periodic structure are rigorously considered in the IMCM, both the dispersion and Bloch impedance characteristics can be accurately and effectively extracted with simulation or measurement only once, however strong the coupling intensity is.As examples, the proposed IMCM is applied to extract the dispersive properties of the classical reciprocal asymmetric microstrip composite right-/left-handed transmission lines(CRLHTLs)in the unbalanced and balanced states, and the extraction results are compared to those from the traditional eigenmode method, unwrapping method(UPM)and single cell method.Furthermore, S parameters of the microstrip CRLHTL are retrieved using the extraction results of the IMCM and the UPM, and the former S parameters coincide perfectly with the full-wave results, confirming the accuracy of the IMCM.关键词：improved macro cell method;artificial periodic transmission line;dispersion and Bloch impedance characteristics2|2|0更新时间：2025-07-16
- 摘要：Given that the attacker has the side information of adaptivity criterion, it is an urgent problem for the steganographer to improve the security of large-payload and adaptive steganography.This paper proposed a game-theoretic model for the two sides.Through theoretical derivation, we provided the necessary conditions for game equilibrium, along with the mixed strategies and expected payoffs of the two sides in equilibrium.Results of numerical simulation validated the theoretical analysis.This research reveals that the attacker's strategy is independent of the number of hidden bits, and the expected payoff increases with the number of hidden bits.The probability that one position is selected by steganographer to embed more bits is always greater than zero and increases with the complexity of that position.These conclusions bring some guidance for devising secure adaptive steganography with large payload.关键词：steganography;game theory;large-payload;equilibrium2|2|1更新时间：2025-07-16
- 摘要：Aiming to adverse influence on the filtering precision of nonlinear state estimation caused by the random observation noise and the improvement of larger calculated amount from linear state estimation in marginalized particle filter, a novel real-time marginalized particle filter based on weights consistency optimization is proposed.Firstly, according to the extraction and utilization of prior information from observation system model, the consistency optimization method of particle weights in observation lifting scheme is given by the construction of consistency distance and consistency matrix, which improves the filtering precision of particle filter used in nonlinear state estimation.Secondly, the real-time marginalized particle filter is proposed by the structure optimization of time update and observation update steps, which decrease the computational complexity of Kalman filter used in the linear state estimation in view of Monte Carlo simulation principle.Finally, the concrete steps of new algorithm are given by the dynamic combination of the consistency optimization method and the real-time marginalized particle filter.The filtering precision and calculated amount of new algorithm is analyzed on the basis of single station radar observation target tracking simulation scene.The theoretical analysis and experimental results show the feasibility and efficiency of algorithm proposed.关键词：nonlinear estimation;Marginalized particle filter;observation lifting;weights optimization2|2|1更新时间：2025-07-16
- 摘要：In compressed sensing (CS for short) theory, the projection matrix optimization is a kind of approach of improving performance by increasing the amount of information of observational data.This paper presents a CS projection matrix optimization algorithm based on quasi-Newton method.The algorithm is divided into two steps.First, use threshold function to restrain the non-diagonal elements in order to make the Mutual Coherence between the projection matrix and sparse dictionary approximate Welch bound.Second, use Rank two to check and get Hessian matrix inverse to amend the direction of the gradient search.Two steps are alternately performed until the projection matrix which meets the requirement of the optimal solution is worked out.This algorithm always maintains descent and has a super-linear convergence rate, which requires less computation.Experimental results show that when signal sparse degree or observation data is identical, this proposed algorithm outperforms other algorithms.关键词：compressed sensing;projection matrix optimization;Gram matrix;quasi-Newton method2|2|4更新时间：2025-07-16
- 摘要：For SLA-aware service composition problem (SSC), a multi-objective discrete particle swarm optimization algorithm (MDPSO) is proposed in this paper and an optimization model for this algorithm is also built.According to the character of this SSC problem, a particle updating strategy is redesigned by introducing crossover operator.A particle mutation strategy is proposed to increase the swarm diversity and restrain particle swarm's premature convergence.In addition, algorithm MDPSO+ is formed by incorporating a local search strategy based on constraint-domination into the algorithm MDPSO.At last, some parameters in algorithm MDPSO are analyzed and set with relative proper values, and then the algorithm MDPSO and the algorithm MDPSO+ are compared with the recently proposed algorithm E3-MOGA and NSGA-II on different-scale cases;the results show that algorithm MDPSO+ can solve the SSC problem more effectively.关键词：MDPSO;service level agreement;swarm diversity;local search2|4|4更新时间：2025-07-16
- 摘要：Because the existing single channel speech enhancement technologies perform not well in the tracking and suppression of non-stationary noise, the speech enhancement method based on online energy adjustment is proposed.The normalized critical band energy parameters are employed as the feature in Gaussian mixture model (GMM) to distinguish the background noises.Based on the AR-HMM of clean speech and the noise of corresponding type, the power spectrums of speech and noise are estimated under minimum mean square error (MMSE) criteria.When the differences between the training data and test data are considered in the non-stationary noise environment, the online adjustment method for the speech and noise models is necessary.The scaling factor of speech energy is estimated with the iterative expectation maximization (EM) algorithm and the one of noise energy is estimated with the re-estimation approach similar to the training stage.And the initial scaling factor of noise energy is obtained by minima-controlled recursive averaging (MCRA) algorithm.The evaluation of the proposed method is performed under the standard of ITU-T G.160.The test results reveal that, comparing with the two reference methods, the proposed method performs well in non-stationary noise environments, including larger noise reduction and shorter convergence time.关键词：speech enhancement;non-stationary noise;hidden Markov model;Gaussian mixture model2|2|4更新时间：2025-07-16
- 摘要：The implicational irreducible elements, finite implicational decomposable elements and finite implicational decomposable irreducible elements based on linguistic truth-valued lattice implication algebra were discussed in this paper, their structure characteristics were investigated about implicational irreducible elements, finite implicational decomposable elements, and finite implicational decomposable irreducible elements, and it is proved that a part elements of linguistic-valued lattice implication algebra were generated by tensor product operation.关键词：linguistic truth-valued lattice implication algebra;implicational irreducible element;finite implicational decomposable element;finite implicational decomposable irreducible element2|2|0更新时间：2025-07-16
- 摘要：Fault detection and diagnosis for Air-Conditioning(AC)system in intelligent building is the guarantee of building safety, comfort and energy-saving.However, the identification of unknown modes for AC system is still one of the key difficulties.The Gaussian Mixture Model(GMM)is not confined to a specified probability distribution and the distribution of given data can be obtained on the basis of classification.With excellent computing performance any continuous distribution can be fitted via GMM.Hence, a new idea of clustering based on GMM to identify the unknown operation modes in AC is developed.The simulation experiment has qualified the accuracy and reliability of this GMM mode identification approach.关键词：air-conditioning(AC)system;operation mode;Gaussian mixture model(GMM);identification approach2|2|0更新时间：2025-07-16
- 摘要：2D-to-3D conversion is a feasible solution to the problem of 3D-content deficiency.In the conversion, depth extraction from a single 2D image is the key step.We propose a depth estimation method based on edge-gradients ratio and object-guided energy model.First, we obtain two blurred images from the input defocused image via Gaussian smoothing using two different kernels.Then, we estimate the sparse depth map generated from the gradients ratio at edge locations in the two blurred images.Next, we recover the full depth map from the sparse depth map by matting Laplacian interpolation.Objects are then extracted from the input image by adaptive threshold binary segmentation on its visual saliency map.Finally, the refined depth map is obtained through object-guided depth filtering.Synthetic and real images experimental results both show that our algorithm is superior to the existing methods.关键词：2D-to-3D;defocused image;depth map;visual saliency;depth refinement2|2|3更新时间：2025-07-16
- 摘要：The dynamic testing for automaticlly identifing security vulnerabilities in binary executables has received increasingly interest in recent years.In this paper, we present a new automated whitebox fuzzing tool EWFT(Execution-based Whitebox Fuzzing Tool), which implements dynamic symbolic execution and taint tracing techniques during program execution.Our contributions are:1)we propose a ROBDD(Reduced Ordered Binary Decision Diagram)-based approach to analyse execution process, 2)we introduce a new path weight analysis algorithm(PWA)for searching path space and automating test data generation, and 3)we build a prototype tool that automatically finds software vulnerabilities.Results of our experiments show that execution-based whitebox fuzzing is powerful to identify variety of security vulnerabilities in real applications.Compared to the related work in the research area, it explored deeper program paths on the average, and achieved higher structural coverage.关键词：dynamic test;software vulnerability analysis;test generation;data compression2|2|3更新时间：2025-07-16
- 摘要：Chain of trust (CoT) is one of the key technologies for constructing trusted system.As viewed from theories and application systems of CoT, this paper introduced several representative models and the latest investigations including noninterference-based CoT theory and composition security-based CoT theory firstly.Afterward, this paper expatiated advantage and shortage of two CoT theories in detail.Secondly, this paper introduced the development of application systems comprising static CoT and dynamic CoT, and analyzed the remote attestation technology of chain of trust, and presented the CoT systems in cloud computing environment, and analyzed the security deficiency of those systems, and then discussed the conformance testing and security evaluation for CoT application system.Finally, this paper put forward the research and development trend for CoT.关键词：trusted computing;theory of CoT (chain of trust);noninterference theory;composition security theory;static CoT;dynamic CoT;security of CoT application systems2|2|10更新时间：2025-07-16
- 摘要：With the rapid development of Internet of Things(IoT), heterogeneous physical entities have been connected to the network to form massive virtual resources, which bring many new challenges to the name service in both performance and functionality.From a performance point of view, we firstly give an in-depth analysis and detailed comparison among different resolution services and discovery services which are based on hierarchical DNS technology, flat DHT technology or mixing the two technologies.Then from a functionality point of view, we describe the latest research for the purpose of addressing three key issues:compatible for heterogeneity, equitable and federated resolution, and privacy protection.Finally, we summarize the development trends of name service and indicate the future research directions.关键词：Internet of Things;name service;naming;addressing;resolution;discovery2|2|1更新时间：2025-07-16
- 摘要：In the paper, we mainly focus on classifition on multi-view data.Considering that ensemble methods can combine weak classifiers to construct a strong classifier, and topic model can learn latent representations from complex data, we try to introduce ensemble idea to topic model, such that predictive latent representation could be obtained and multi-view classifier could be learned.We propose multi-view supervised latent Dirichlet allocation (multi-view sLDA) model by combining latent Dirichlet allocation model and the mixture of softmax model which is an ensemble classification model.Moreover, we derive a parameter estimation algorithm of the proposed model based on variational expectation maximization (EM) procedure.The experimental results on two real datasets show the effectiveness of the proposed model.关键词：multi-view classification;probabilistic topic model;variational expectation maximization2|2|1更新时间：2025-07-16
- 摘要：Considering the hardware resources limitation in the satellite onboard IP switch, a high capacity shared memory switch fabric with 8 priorities, variable-length packets scheduling mechanisms and pointer copy is presented.The specific structure, the key scheduling algorithm and the working processes of the circuits are provided.Xilinx V4sx55 FPGA are used to realize a 8×8 switch fabric, the circuits occupy 164K bytes on-chip memory resources and 5982 4 input lookup tables, which can meet the requirements of triple modular redundancy.When the working frequency is 100MHz, 64 bit width off-chip SRAM, the peak throughput of the switch fabric can reach 1.6Gbps.Using 64 bit width, 133MHz DDR off-chip memory, the peak throughputs can reach 4.25Gbps.The fabric can be used in multi-stage switch fabrics which can meet the demand of throughputs over 10Gbps.关键词：satellite onboard IP switch;variable-length scheduling;queue management2|2|0更新时间：2025-07-16
- 摘要：A camera calibration method based on three orthogonal constraints was presented for determining intrinsic parameters.Camera coordinate system was set as world coordinate system, so only 5 camera intrinsic parameters and 1 projection scale factor need to be solved.A calibration pattern containing 7 spatial points was developed which can be moved and rotated in the camera's field of view.At least 2 images were captured to set up constraint equations.Thus, camera intrinsic parameters can be solved in the closed-form solution based on matrix eigenvalue decomposition.In calibrating the same camera, the method performed the same as the classical plane-based calibration method, relative difference is about 1.3%.Experiments with both synthetic and real data show that our method has high accuracy and is robust.关键词：camera calibration;projection equation;orthogonal constraint;closed-form solution2|2|3更新时间：2025-07-16
- 摘要：Based on Erlang-A and Erlang-C, a decentralized cloud computing system composed of multiple cloud domains is simplified to multiple queuing systems.The admission control of delay-sensitive service requests can be implemented based on abandonment rate, since waiting service requests are overflowed at a certain abandonment probability.The abandonment probability is introduced into Riordan Formula, while the asymptotic peakedness factor of aggregate overflow based on spatial stochastic process is introduced into Hayward's approximation.The overflow loss performance is studied using equivalent random theory.The performance improvement of the multiple queuing systems is testified by the numerical simulation under admission control based on abandonment rate.关键词：cloud computing;multiple cloud domains;loss performance;overflow load;abandonment rate2|2|3更新时间：2025-07-16
- 摘要：Configurable business process model enable the sharing of common processes among different organizations in a controlled manner, this model is intended to be configured to meet the requirements of specific organizations, then leading to individualized process models, so it is important issue to formal modeling and verify for configurable business process model.Owing to the characteristic of goal model can express users' intentions, in this paper, we provide a novel analytical method of configurable business process model which based on the goal model, in this method, we add the goal model to WF-net (GWF-net) and incorporate users' intentions into business process model;following, we transform the ordinary business process model expressed by GWF-net into configurable business process model by adding the configuration operation;finally, presents its correctness analysis of configurable GWF-net and provide the consistency theorem between the users' requirements and configuration procedure of configurable business process model, so that we ensure the validation of business process model through the fulfill goal.关键词：goal model;GWF-net (Goal WF-net);configurable business process model;process configuration2|2|6更新时间：2025-07-16
- 摘要：For the nonlinear filtering problem of target tracking in aperiodic sparseness sampling environment, a novel auxiliary quadrature particle filter(AQPF) based on Gauss-Hermite quadrature and target characteristics is proposed.In the proposed algorithm, a set of quadrature point probability densities based on the Gauss-Hermite quadrature is proposed to approximate the important density function.At the same time, the proposed algorithm can incorporate target observation, time interval of the target observation and the target speed into the construction of important density function, which can effectively enhance the diversity of samples and improve the performance.Finally, the experimental results show that the performance of the proposed algorithm is better than these of the unscented Kalman filter(UKF), quadrature Kalman filter(QKF), particle filter(PF), auxiliary particle filtering(APF)and Gaussian particle filter(GPF), and can effectively estimate the target states.关键词：aperiodic sparseness sampling;Gauss-Hermite quadrature;quadrature particle filtering;target characteristic2|3|1更新时间：2025-07-16
- 摘要：In two-tiered wireless sensor networks, a query-driven mode means that queries are processed in a distributed way at the sensor network level of the tiered architecture.When the data generating rates of the sensor nodes are high and the query frequencies are low, using query-driven mode can deeply shrink the amount of data flow and decrease the energy consumption of the sensor nodes.Under such mode, how to support region-based Top-k queries efficiently is a challenging problem.To solve this problem, firstly, a novel data aggregation tree named DAT is constructed.Then, a novel data aggregation scheme for region-based Top-k queries is proposed based on DAT.Theory analysis and simulation results show that, compared with existing schemes, our proposed scheme performs much better in efficiency.关键词：query driven;data aggregation;Top-k;two-tiered sensor networks2|2|4更新时间：2025-07-16
- 摘要：For the public key encryption scheme based on the ergodic matrices constructed by Pei et al., this paper proves that breaking this scheme is not harder than solving polynomial discrete logarithm problem on finite field applying the properties of ergodic matrices and linearization method.Thus, we show that their proof of security is not correct for this public key encryption scheme.关键词：public key cryptography;ergodic matrix;discrete logarithm problem;security analysis2|2|2更新时间：2025-07-16
- 摘要：It has a great significance to analyze the elastic deformation of the vessel wall for cardiovascular diseases' clinical treatment and the selection of the surgical plan.On the premise of making reasonable assumptions, firstly, establish the deformation model of infinitesimal's displacement.Secondly, use the finite element analysis method to divide the area of the vessel wall into a number of triangular surface infinitesimal, export the triangular surface deformation model by the displacement functions of triangle's three vertices and three sides.Finally, this deformation model is verified by simulation, compared with the literature methods, this method shows that it is able to not only calculate the size but also show the direction of the strain and give the results of the strain in three directions.关键词：vessel wall;small strain;mechanical model;medical image analysis2|2|2更新时间：2025-07-16
- 摘要：In order to reduce the complexity of the issue of acoustic and video image calibration.A kind of calibration method of the deviation between acoustic image and video image with microphone array is studied.The formulation of calibrating the deviation is deduced based on the basic problem(translation、rotation and scaling)of the acoustic image and video image.A compound sound-light calibrator is designed to achieve a value of the coordinate deviation of acoustic and video image.By repeating the experiment at five different positions, five group deviated coordinates are achieved.Five correction values are obtained depend on the calibrated modal in this paper.The calibration of the deviation between the sound and light will be accomplished by adding the calibration value into the Microphone array acoustic imaging algorithm.The experimental result shows that the error is 0.12°, which is in the range of allowance error(0.2°).This calibration method is could be as a general method to calibrate acoustic image and video image.关键词：microphone array;acoustic image;video image;deviation;calibration method2|2|1更新时间：2025-07-16
- 摘要：A ridge regression-based diagonal loading method is proposed.The absolute residual is used as the penalty function in the algorithm by analyzing the curve of the number of snapshot with residual.The least squares estimation for the variance of residuals is replaced by absolute approximation to enhance the robustness of the ridge parameter.The simulations demonstrate that the method can suppress the fluctuation of side lobe not only in small sample number but also in the circumstance with array errors.关键词：beamforming;diagonal loading;ridge regression;least squares;penalty function2|2|2更新时间：2025-07-16
- 摘要：To make an optimal trade-off between the tracking accuracy and the radiation risk in a period of time, this paper studies the scheduling problem of selecting the active/passive sensors in the multi-platform for target tracking.The problem is formulated as a partially observable Markov decision process (POMDP), which can take both target tracking and emission control into account.Based on the foresight optimization, the approximate accuracy reward and the radiation cost, which are derived from the unscented transformation sampling and hidden Markov model (HMM) filter respectively, transform our problem into a tree search problem, and the branch and bound method is used for problem solution.The simulation results demonstrate the effectiveness of our approach.关键词：sensor scheduling;partially observable Markov decision process;foresight optimization;unscented transformation sampling;branch and bound2|2|3更新时间：2025-07-16
- 摘要：A compact multiframe myopic deconvolution algorithm in the frequency domain is described that utilizes multiframe short exposure images and the corresponding turbulent atmosphere phases from wave front sensing.Firstly, the algorithm employs the estimated point spread functions (PSFs) based on the turbulent atmosphere phases to adjust to be better correct forms gradually.The cost function that uses Fourier spectral ratio to reducing the number of unknown variables is minimized alternately to restore the object image and estimate PSFs by conjugate gradient algorithm.To diminish noise amplification in the frequency domain and avoid the reconstructed image turning to be a local minimum, the structure-adaptive applicability filter (SAAF) and multiple basis constraints are used.Computer simulations are conducted to investigate the performance of the proposed method offer the possibility of improved object reconstructions over multiframe Tikhonov regulation deconvolution and multiframe Richardson-Lucy deconvolution.关键词：exposure image;myopic deconvolution;spectral ratio;structure-adaptive applicability filter;conjugate gradient2|2|0更新时间：2025-07-16
- 摘要：This paper proposes a method for aerial ocean images segmentation based on multi-gauss characteristic space cover learning.Firstly, we analyze the distribution characters of sea background images and find that they are diversity in location, direction and geometrical morphology but clustering and can be covered by one or more spheroids.Then, we use the multi-gauss model to describe them and get the number of gauss components adaptively based on the maximum Bayesian posteriori probability and 3δ criterion.Finally, we segment the aerial ocean images series according to their cover learning results.The experimental results show that this method can get the cover learning model accurately and effectively and segment the aerial ocean images with high precision and low error in less time.关键词：aerial ocean images;multi-Gauss model;characteristic space;cover learning;image segmentation2|2|3更新时间：2025-07-16
- 摘要：Based on the analysis of the configuration and the character of the circularly polarized antenna with tilted beam, a novel CSRR-FS(Complementary Split Ring Resonator with Flower-Spiral, CSRR-FS)structure is proposed to increase the bandwidth of the antenna.This structure is designed through the flower-spiral arm and five complementary split ring resonator(CSRR)splits loaded on ground plane.The VSWR(voltage standing wave ratio)is enhanced through the flower-spiral structure.And respectively, five CSRR splits are loaded on the perfect electronic conductor ground plane to miniaturize the ground plane and decrease the cross-polarization component.The axial ratio is improved through the ground plane loaded five CSRR splits.Simulated and measured results both show that the relative bandwidth of the novel antenna with the CSRR-FS structure is 24% from 5.5GHz to 7GHz in the condition of circularly polarized radiation.And while, it is an azimuth angle of 30° tilted beam by the CSRR-FS structure.The bandwidth increases 1.8 times as wide as one without the CSRR-FS structure in the same condition.The proposed structure is an effectively method for increasing the bandwidth of circularly polarized antenna with tilted beam.关键词：circularly polarized antenna;tilted beam;flower-spiral structure;CSRR2|5|0更新时间：2025-07-16
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