最新刊期
卷 40 ， 期 6 ， 2012
- 摘要：When carrier frequency agility is applied to SAR system,there could be some problems,such as Doppler chirp rate agility,focus-out in azimuth,etc.After we analyzed the phase characteristic of radar echo,correlation algorithm was applied to pulse compression in azimuth firstly.Considering the connatural problems of low efficiency and high side lobe level that correlation algorithm had,pulse compression algorithm based on compressed sensing was presented,which made use of the sparsity of echo signals.Then,a strategy about frequency agility SAR imaging was proposed which involves pulse compression in range based on matching filter and pulse compression in azimuth based on compressed sensing.The results indicate that imaging strategy can both conquer Doppler chirp rate agility and achieve frequency agility SAR imaging,which has the merit of lower side lobe level and higher resolution.关键词：SAR;carrier frequency agility;pulse compression in azimuth;compressed sensing3|2|5更新时间：2025-07-16
- 摘要：The micro-motion feature extraction for ballistic target has attracted great attention in recent years.Because of the limitation of the angle of view,only the characteristics of micro-motion projected in the line-of-sight (LOS) could be extracted in monostatic radars.In the paper,the distributed radar networks are utilized to obtain the three-dimensional micro-motion features of ballistic targets with empennages.Profited from the multi-view of distributed radar networks,the 3-D coning vector of target is reconstructed from the micro-Doppler parameters of the scatterer on the cone apex of ballistic target,and then the precession period,spinning period,precession angle,the radius of cone bottom,and the intersection location of the spinning axis and the conning axis are solved by analyzing the relationship between the micro-Doppler curves and the precession motion of the scatterers on edge of the cone bottom.The length of target is also estimated.Simulations validate the effectiveness of the algorithm,and the robustness of the algorithm is also analyzed.关键词：micro-Doppler (m-D);distributed radar networks;ballistic target;auto target recognition (ATR)2|2|11更新时间：2025-07-16
- 摘要：With the development of high resolution (HR) synthetic aperture radar (SAR) imaging,the technology of building 3D information extraction from SAR images is becoming an important issue in radar remote sensing.In order to retrieve building height information from single HR SAR image,a model-based height estimation approach is proposed.An orthographic projection model is established to achieve the quick generation of the model hypothesis.A segmentation-based likelihood function is derived to examine the consistency between the model hypothesis and the actual SAR image.The hypothesis test procedure,which is iterated with the simulated annealing algorithm,is designed to optimize the hypothesis from the high dimensional model space.The experimental results using both of the simulated and actual airborne SAR images show the effectiveness of the proposed method.关键词：high resolution synthetic aperture radar image;building height retrieval;3D geometric parameterized model;projection model;likelihood function2|2|4更新时间：2025-07-16
- 摘要：One of the open issues of Dempster Shafer theory is how to determine basic probability assignment function (BPA).To solve this problem,a method to determine BPA based on interval numbers is proposed in the paper.At first,the model of interval numbers is constructed with the samples.Then the distance of interval numbers is used to represent difference among the attributes of the samples,so the similarity of them is calculated.At last,the similarity is normalized to get the value of BPA.The effectiveness of this method is proved by classifying the Iris Set.It concludes that the total recognition rate is 96%.This method is simple and practical;it can determine BPA in the case of the little number of the samples.关键词：evidence theory;BPA;interval number;similarity;data fusion;recognition2|2|29更新时间：2025-07-16
- 摘要：The existing salient object extraction algorithms had high time complexity and didn’t take the integrity of the objects into account,and a salient object extraction algorithm is proposed,which is adaptive to the resource-constrained environment.The mathematic model of sparse representation is built.The corresponding relation between the salient objects and spare representation,edge energy approximation pattern among regions,and gradual change pattern between adjacent regions are induced.The candidate regions are determined based on the relation,and the salient objects are locally extracted based on gradual change pattern and edge energy approximation pattern.The contrast experiments indicate that the salient objects are captured accurately and the integrity of the salient objects are well-kept under given conditions with the proposed algorithm.关键词：time complexity;object local-abstraction;sparse representation;gradual change pattern;approximation pattern of edge energy2|2|1更新时间：2025-07-16
- 摘要：For the optimization problem of rectangular packing in manufacturing field,a genetic-discrete particle swarm optimization is proposed.Through introducing the concepts of exchange operator and exchange sequence,the difficult problem of describing the update particles in the standard particle swarm optimization algorithm for combinatorial optimization problem is solved.Combining the idea of mutation and crossover in genetic algorithm strengthens the diversity and stability of the particle swarm.An improved lowest horizontal search algorithm is proposed to accelerate the convergence speed and can be used to decode to packing layout.The experimental data show that the proposed algorithm is effective and robust in solving the problem of rectangular packing.关键词：descrete partical swarm optimization;genetic alogorighm;lowest horizontal search algorithm;rectangular packing4|1|2更新时间：2025-07-16
- 摘要：The performance of these access protocols decreases dramatically when the node number increases in WLAN.To resolve this problem,we propose an adaptive backoff algorithm by estimating the active node numbers with multiple thresholds.The proposed algorithm optimizes the delay model and gives a linear function between the contention window and the active node number,and an accurate contention window index is given for the optimal contention window scheme.Then,we realize the estimation of node number by using three thresholds to identify four levels of node number changes with a calculation of the idle slot intervals.The theoretical analysis shows that the proposed backoff algorithm holds low collision probability and larger throughput,and the node number has little impact on the performance.The simulation results demonstrate the validity and scalability of the algorithm.Moreover,it outperforms other algorithms in fairness as well.关键词：IEEE 802.11;WLAN;backoff algorithm;throughput2|2|2更新时间：2025-07-16
- 摘要：The uniform search particle swarm optimization (UPSO) algorithm formula was tsansformed into a differential equation.Solving the differential equation,we get a non-recurrence location update formula,and the UPSO's convergence region for learning coefficient c and inertia coefficient w were concluded by deducing the solution convergence conditions.Finally simulation experiments were provided on the selected location of the region of convergency by 6 Benchmark functions.Experimental results show that UPSO converges when the learning coefficient and inertial coefficient are in the convergence region and diverge outside convergence region.关键词：particle swarm optimization;uniform search particle swarm optimization2|2|7更新时间：2025-07-16
- 摘要：DUET is a famous algorithm to resolve underdetermined problem using time frequency mask.Effect on rotation transform on DUET is discussed and an improved DUET algorithm is proposed in this paper.The algorithm rotates the mixtures and mixing matrix using the rotation matrix,which is formed by any two columns in the mixing matrix,and then do DUET algorithm.Because the results are different in DUET algorithms under different rotations,the algorithm sums the results to improve the distortion.Finally,several speech signal experiments demonstrate its performance and practice.关键词：underdetermined blind source separation;sparse component analysis;disjointness;time frequency mask;l0-norm2|2|0更新时间：2025-07-16
- 摘要：With the wide application of cyber-physical systems(CPS),it is of vital importance to ensure that the design and implementation of CPS meet critical performance requirements (e.g.,security,reliability).This paper presents a framework for CPS modeling and verification.In the framework,CPS are modelled by HybridUML and then the generic model is transformed to a formal model that is suitable for reasoning with the help of formal methods.The formal method adopted is differential dynamic logic(dL) whose operational model is hybrid program(HP).When transforming a HybridUML model to its corresponding HP presentation,transformation rules are defined according to semantic consistency.After transformation,CPS properties are specified on the basis of the resulting HP,and finally,the properties are automatically verified through the theorem prover KeYmaera.关键词：CPS;differential dynamic logic;HybridUML;model transformation;verification2|2|12更新时间：2025-07-16
- 摘要：In service-oriented computing networks,it is urgently needed to objectively evaluate service entity's QoS.In previous studies,service entity's QoS is only a weighted QoS that is perceived by users.It cannot objectively reflect the QoS that the service entity can provide in actual network environment.Combined with the actual service composition environment of service entities to characterize QoS of the service entity,a policy for the trusted QoS evaluation and service selection with environment aware is proposed:(1) the QoS of service entity is characterized with different load QoS feature vectors;(2) a trust reasoning and evolution mechanism subjected to trusty entity is established to effectively avoid the shortage of creditable generalization in the trust evolution mechanism;(3) the creditability of service entities and QoS feature vector are deduced based on service entities through the trust evolution;(4) combined with the current service load,a more objective evaluation of QoS that service entities actually provide is obtained.Finally,an integrated trusted QoS evaluation and service selection algorithm is given.Experimental results demonstrate the effectiveness of the policy.关键词：service composition;QoS evaluation;trust reasoning;service selection;Quality of Service2|3|7更新时间：2025-07-16
- 摘要：An approach was proposed for building segmentation from high resolution SAR (Synthetic Aperture Radar) images based on an improved Markov random field (MRF) model.Aiming at the property of low SNR (Signal to Noise Ratio) of SAR images and the complexity of building textures,we obtained the initial segmentation using the maximum likelihood (ML) algorithm based on the multi-scale MRF model and involved the Gabor similarity between pixels based on the traditional MRF potential function,and employed the ICM (Iterative Conditional Model) algorithm to implement the segmentation.The experimental results on several real SAR images show that the proposed approach performs better than traditional methods in the segmentation accuracy,and building boundaries are clearly obtained by the proposed approach.关键词：high-resolution SAR image;building segmentation;multi-scale Markov model;Gabor feature2|3|10更新时间：2025-07-16
- 摘要：The wideband bistatic echo of a precession cone-shaped target is modeled and the procession parameter estimation method is proposed based on the monostatic and bistatic high resolution range profile (HRRP) sequences and extended Hough transform.Then,the bistatic ISAR imaging model of precession target is introduced and the optimum imaging time is derived.By selecting the optimum bistatic HRRPs,a clear bistatic ISAR is obtained via the classical fast Fourier transform processing.Finally,the dynamic simulation results based on the monostatic and bistatic scattering coefficients of a cone-shaped model calculated via the FEKO software validate the proposed method.关键词：bistatic radar;precession;parameter estimation;inverse synthetic aperture radar2|2|5更新时间：2025-07-16
- 摘要：During the process of motion for humanoid robot,it may fall due to some uncertainty factors.Since the falling is inevitable,research on the optimal control of falling for humanoid robot is achieved.By thorough analysis of falling action,optimal control for falling action based on parameter optimum is proposed.For the sensitivity of initial value of problem and lack of SQP (Sequence of Quadratic Programming) in the parameter optimum method,a filter of initial states is designed and a method based on improved SQP filter algorithm is present to improve the optimization process.The optimization results are obtained by comparing with control of the minimum principle and finally the control method is validated in the simulation and experiment.关键词：humanoid robot;falling motion;optimal control;parametric optimum2|2|1更新时间：2025-07-16
- 摘要：The exponential stability of a class of cellular neural networks with multi-pantograph delays is studied.In view of nonlinear measure,a sufficient condition is derived for the existence,uniqueness and exponential stability of the equilibrium point.And the method gains the exponential convergent velocity of the solutions.Finally,an example is provided to illustrate effectiveness of the method.关键词：cellular neural networks;exponential stability;pantograph delay;nonlinear measure;convergent velocity2|3|11更新时间：2025-07-16
- 摘要：A discrete glowworm swarm optimization (DGSO) algorithm is designed to tackle the travelling salesman problem.A new encoding schema and decoding schema are given with the characteristics of the TSP problem,and a new distance formula and encoding update formula for the new algorithm are given.In order to enhance the capability of the algorithm local searching,and to speed up the algorithm convergence speed,the 2-opt local search scheme is integrated into the new algorithm for solving TSP problem.The proposed algorithm was evaluated on 10 TSP test problems.The numerical experiments show that the proposed algorithm can find the global optimal solution with less computation and evolving time.In case of large scale TSP algorithm can achieve optimal solution of the theory and the error of the optimal solution is also less than 1%.关键词：discrete glowworm swarm optimization algorithm;glowworm swarm optimization;TSP;2-Opt2|2|42更新时间：2025-07-16
- 摘要：A convenient and efficient approach of removing the spurious DC modes in three-dimensional finite-element solution for modeling complex cavity is proposed.This method is based on higher-order hierarchical basis functions.Application of this approach results in a robust,accurate and efficient eigenmode solver of complex cavity which significantly saves the memory as well as computational time compared with the commercial electromagnetic software.关键词：cavity;finite-element method;spurious modes;multi-beam klystron;hierarchical basis2|2|1更新时间：2025-07-16
- 摘要：Based on the simplified circuit model of the commercially available Varactor diode,TRL analysis on quartz is introduced in this paper for the analysis of the passive parts of the diode chip.The diodes chip model in 3mm is setup by the analysis of all the parasitic parameters and working environment.By using TRL arithmetic,the values of lumped elements in the diode chip model are determined.The measured on-wafer results agree well with simulated results of the diode chip.The methods of modified diodes chip model may find its applications in the design of millimeter circuits such as mixers and frequency multipliers.关键词：GaAs Varactor diode;chip circuit model;discontinuity;millimeter-wave2|2|0更新时间：2025-07-16
- 摘要：For the problem of recovering sparse vector with noisy measurements,robust approximate l0 norm minimization algorithm is proposed.Firstly,l0 norm is approximately expressed by arctan function.Secondly,the model of sparse recovery in the present of noise is constructed based on approximate l0 norm.Finally,the model is solved by quasi-Newton method to estimate sparse vector.Simulation results show that our algorithm needs fewer measurements and provides the better accuracy than the existing methods.关键词：compressed sensing;sparse recovery;basis pursuit;smoothed l0 norm3|2|23更新时间：2025-07-16
- 摘要：Multiple-input multiple-output (MIMO) radar as a new radar system is proposed at the beginning of 21st century,which has been attracting much attention of researchers and institutions all over the world.In this paper,MIMO radar theory is summarized based on the current literature firstly.Then,the potential capabilities of system configuration,signal design,target detection,parameter estimation and high resolution performance are introduced.At the same time,the restricting factors in practical application are pointed out.Finally,some further work and the technical difficulties in MIMO radar are predicted.关键词：multiple-input multiple-output radar;diversity techniques;waveform design;Target Detection;parameter estimation;high resolution2|2|51更新时间：2025-07-16
- 摘要：A confluence of existing researches have shown that using priori knowledge can efficiently mitigate the heterogeneous clutter of airborne/space-based radar.A brief overview of significant progress in knowledge-aided (KA) methods for airborne radar clutter suppression is presented.The recent advances of clutter mitigation methods exploiting a prior knowledge in indirect way,such as associating radar data with dissimilar data,intelligent training and filter selecting,are introduced.Especially,some methods for registration of radar data and other resources data are elaborated.The progress in Bayesian filtering and data pre-whitening which can directly filter the incoming multi-dimensional data stream are analyzed,including the priori covariance matrix estimation,pre-whitened STAP filtering and Bayesian STAP filtering.Furthermore,a brief overview of the KA CFAR algorithms,high-fidelity clutter modeling and validation data of KA-based airborne radar adaptive processing algorithms are conducted.Although great progress has been made in clutter mitigation methods using KA,there are some unsolved problems in the real application.For these problems,we give some idea about using multiple data sources and effectively exploiting prior knowledge.关键词：airborne radar;clutter mitigation;space-time adaptive processing;knowledge aided2|3|14更新时间：2025-07-16
- 摘要：Circuit partitioning is an important stage in the very large scale integration (VLSI) physical design automation,which influences further circuit design.The VLSI circuit partitioning problem is an NP-hard combinatorial optimization problem.In this paper,we propose a scatter search method for the problem,which incorporates the single-vertex-move based Fiduccia-Mattheyses algorithm (FM) within the scatter search framework.The FM algorithm is used for local exploitation,while the scatter search strategy is used for global exploration.To meet the quality and diversity of initial solutions required by the scatter search method,we incorporate the greedy randomized adaptive search procedure (GRASP) with the clustering method to generate initial solutions.Experimental results show that the proposed scatter search algorithm is capable of partitioning large benchmark circuits,and yields results better than those of the well-known multilevel partitioning package hMetis.关键词：scatter search;GRASP;FM algorithm;circuit partitioning3|2|3更新时间：2025-07-16
- 摘要：Multi-input-multi-output(MIMO) scheme at 6GHz is one of the enabling technologies for the next generation mobile communication.However,indoor channel measurement and characterization is rarely conducted at this band.An extensive MIMO channel measurement is performed at 6.0GHz-6.4GHz under typical office environment with channel sounder based on vector network analyzer.Results on path loss,delay spread and spatial correlation,which show great difference compared with those at 2.45GHz in similar environment,are presented. Therefore,our measurement results provide guidance for the design and development of the system working on 6.0-6.4GHz band.关键词：6.0-6.4GHz;MIMO;channel characteristic;channel measurement2|2|4更新时间：2025-07-16
- 摘要：In the process of applying traditional simulated annealing algorithm and tabu search algorithm to solving multi-peak complex functions,the following problems often occur:particles converge to the local optimal solution too fast,the late converge slows down and search ability turns poor.In order to solve these problems,the definition of function complexity is proposed,and adaptive simulated annealing algorithm and tabu search algorithm are presented based on the function complexity.In these algorithms,the step length control parameters are adaptively adjusted according to the function complexity;then rough solution of the function is obtained in terms of regulated step length;finally,and the original step length is used to acquire the global optimal solution.Experiments show that the proposed method cannot only transcend the limits of the local optimal solution,but also reduce iteration of the above algorithms,and efficiently improve local and global search ability.关键词：function complexity;simulated annealing algorithm;tabu search algorithm;function optimization2|2|10更新时间：2025-07-16
- 摘要：A computationally efficient method that combines the subspace and projection separation approaches is proposed for 3-D frequency estimation of multiple sinusoids.From the perspective that 3-D sinusoids is a series of 2-D sliced matrices distributed in the third dimension,frequency parameters in the first dimension are estimated by applying the conventional MUSIC-based method to the covariance of the series of slice in the third dimension.Subsequently,a set of projection separation matrices is constructed to separate and estimate the frequency parameters in the second and the third dimension through a set of slices distributed in the third and the second dimension,respectively.The 3-D frequency parameters are automatically paired.For only the original scale of sampled data array is utilized,and the proposed method is more computationally attractive.Computer simulations show that the proposed algorithm is superior to IMDF and HOSVD methods of 3D case in terms of estimation performance and computational complexity.关键词：3-D frequency estimation;subspace-based method;projection separation approach2|2|2更新时间：2025-07-16
- 摘要：An improved affine projection algorithm for network echo cancellation with its fast version is proposed to increase the convergence speed.On the basis of the sparse structure characteristic of network echo path,each coefficient of adaptive filter in the new algorithm obtains different step-size in proportion to its current absolute value,which leads to high overall convergence speed.Statistical analysis of the new algorithm provides theoretical basis for its outstanding capacity in converging to the objective system.The simulation result verifies that the new algorithm achieves faster convergence speed and lower final misalignment.In addition its low computational complexity satisfies the requirement of real-time system.关键词：network echo cancellation;sparseness;affine projection algorithm;proportionate affine projection algorithm2|3|6更新时间：2025-07-16
- 摘要：A nonlinear filtering method called Interacting Multiple Region Model (IMRM) is proposed to estimate the state and continuous system parameter together.IMRM regards the continuous system parameter space as a set of disjoint sub-regions,and each sub-region is assigned to a sub-model respectively.IMRM runs a bank of sub-filters in parallel.At each time step,IMRM computes the mixed initial condition for each sub-model by interaction operation,and each sub-filter estimates the state and system parameter on the condition that the system parameter belongs to a unique sub-region.In order to implement the IMRM efficiently,Unscented Transformation based IMRM (UT-IMRM) is developed by using the unscented kalman filter as the sub-filter.A target tracking experiment is designed to test the performance of UT-IMRM.Experimental results show that UT-IMRM achieves better estimation performance than that of IMM when the system parameter doesn’t belong to the IMM model set.关键词：interacting multiple model;parameter estimation;unscented Kalman filter2|2|0更新时间：2025-07-16
- 摘要：Aimed at the strong nonlinear and non-Gaussian characteristics of maneuvering target tracking system under compound K noise,an adaptive unscented particle filter (AUPF) algorithm is proposed.Based on constant acceleration (CA) model and its modified filtering algorithm,the algorithm adopts a new proposal distribution which combines unscented Kalman filter (UKF) and strong tracking filter (STF) and enhances the system performance for tracking general mobile and step mobile.The AUPF algorithm is applied to track several kinds of typical maneuvering targets based on the model of compound K noise.And the comparison with the unscented particle filter (UPF) algorithm is given.The simulation results show that AUPF algorithm has good track performance for tracking various maneuvering targets and has high tracking precision.关键词：maneuvering target;constant acceleration model;AUPF algorithm;strong tracking filter;compound K noise2|2|5更新时间：2025-07-16
- 摘要：This paper investigates the design of image transition junction of half mode substrate integrated waveguide(HMSIW)and its potential application in the design of power splitter.Firstly,the limitation of applying HMSIW to design power splitter is revealed and then an image transition of HMSIW(ITHMSIW)is proposed followed by the introduction of the design principle.With simulation and experimental analysis,the feasibility of HMSIW equipped with image transition is validated in comparison with HMSIW.After that,an HMSIW crisscross three-way power splitter with image transition junction is designed and tested.The corresponding results illustrate that the HMSIW image transition proposed has good performance and can effectively extend the application areas for HMSIW in microwave and millimeter-wave power splitter design.关键词：half mode substrate integrated waveguide;power splitter;substrate integrated waveguide2|2|0更新时间：2025-07-16
- 摘要：The eigenvector method for maximum-likelihood estimation of phase error has better algorithmic performance than phase gradient autofocus (PGA).However,this method requires eigendecomposition of the sample covariance matrix,which is a computationally expensive task and also limits the real-time application.In order to overcome such difficulty,an autofocus algorithm using the projection approximation subspace tracking (PAST) approach is proposed.With this method,the procedures of covariance matrix estimation and eigendecomposition can be avoided and the computational cost can be reduced to the level of that of PGA.Monte Carlo tests and real SAR data validate that the new approach outperforms PGA.关键词：phase gradient autofocus (PGA);eigenvector method;eigendecomposition;projection approximation subspace tracking (PAST)4|3|5更新时间：2025-07-16
- 摘要：This paper puts forward a method for automatically extracting the P300 from electroencephalography (EEG) signals within several trials based on Infomax independent component analysis (ICA).An algorithm for signaling equilibrium is proposed to enhance the effectiveness of ICA decomposition.After the mixed signal is decomposed by Infomax ICA,the independent component (IC) of P300 is automatically selected according to the standard deviation of the fixed-temporal-pattern of the IC,and applied in P300 reconstruction.Experimental results show that the P300 can be obtained automatically after six trials on the experimental data,and the result of its Pearson correlation coefficient (PCC) within the average of 29 trials (standard signal) is 0.9035.However,the PCC of the average result of six trials and standard signal is only 0.5105,demonstrating the practical applicability of Infomax ICA.This algorithm enhances the objectivity of P300 extraction within several trials.关键词：independent component analysis(ICA);P300;electroencephalography(EEG);fixed-temporal-pattern2|2|6更新时间：2025-07-16
- 摘要：To achieve high diagnostic PET imaging,we propose a novel total variation (TV) based alpha-divergence minimization reconstruction algorithm.The presented cost function uses the alpha-divergence to measure the discrepancy between the measured and the estimated emission projection data and utilizes the TV regularization to regularize the consistency of solution.A semi-implicit iteration scheme is used in the proposed algorithm by adapting the subgradient theory; and then an adaptive nonmonotone line search scheme is taken to guarantee the algorithm convergence.The experiments from the simulated phantom data and the real emission data show that the presented algorithm performs better than the other classical PET reconstruction methods in the noise suppressing and the edge details preserving.关键词：positron emission tomography (PET);alpha-divergence;total variation;adaptive nonmonotone line search2|2|1更新时间：2025-07-16
- 摘要：The identification of phase transition plays an important part on the detection of the weak signal by Duffing oscillator.Traditional identification algorithm has the complicated calculation and the low precision,which confine the applications of Duffing oscillator,so it's necessary to seek a better identification algorithm.In the paper the state equation of Duffing using sine function as the driving force is set up by the Euler-maruyama algorithm.In the filtering process of Duffing with extended Kalman filter,the recursion expression of Kalman gain is derivated,then a new method associated with the gain to identify the phase transition of Duffing is offered,and meanwhile,according to the transition of Kalman gain with the amplitude of signals,the method of weak-signal detection with the joint system is offered.The simulation shows that the method can effectively detect the weak signals.Compared with the Lyapunov identification method,the simulation time of the new algorithm falls two orders of magnitude,and the precision of the calculation improves remarkably.关键词：Duffing oscillator;extended Kalman filter;sine perturbation;identification of phase transition2|2|12更新时间：2025-07-16
- 摘要：A geometric approach for DEMs simplification is proposed.The main idea is to uniformly pick points from DEM in the sense of geodesic metric,resulting in terrain-adaptive samples in Euclidean metric.This method randomly sample point from mesh nodes,then judge if the point can be accepted or not according to its geodesic distance from sampled point set,and repeat the whole process until no points can be added.By defining weighted geodesic distance positively related to terrain variation,results with more points in rugged terrain areas and sparse points in flat areas can be obtained.Moreover,the distribution of samples is very fit for high performance terrain visualization.This method is really simple and can retain the topographical details more effectively.关键词：Poisson disk;DEM simplification;geodesic distance;adaptive sampling2|2|1更新时间：2025-07-16
- 摘要：In order to improve the performance of the traditional optimum space filtering algorithm,a polarization-space adaptive beamforming algorithm based on PSA(Polarization Sensitive Array) was presented in this paper.The signal model and basic idea of the proposed algorithm were given,and then the principle of polarization-space adaptive filtering was discussed.Furthermore,the performance of the proposed algorithm was analyzed and compared through numerical simulations.Theoretical analysis and simulation results show that the proposed algorithm can effectively improve the SINR and reduce the effect of pointingerror,and that it obviously outperforms traditional optimum filtering approach.关键词：polarization sensitive array;polarization-space filtering;adaptive beamforming;eigenspace2|2|6更新时间：2025-07-16
- 摘要：Due to the difficulty in association and estimation of multi-target track in the presence of data association uncertainty,clutter,noise and miss-detection,a fuzzy clustering based algorithm for track continuity in probability hypothesis density (PHD) filter is proposed in this paper.Firstly,a multi-step prediction of current target states is made,and then the weighted labels are assigned to them according to the inertia.Secondly,the fuzzy membership degrees of the current state estimates belonging to the tracks are obtained with the maximum entropy fuzzy clustering.Finally,the tracks are maintained by the use of all the information.Different from the traditional estimate-to-track association,the proposed algorithm does not update the track information by simply summing the log likelihood ratios between adjacent frames,but takes the entire multi-frame information into account by the operations such as weighting and clustering.The simulation results show that the proposed algorithm can maintain target tracks more accurately,even when the targets cross each other,implying strong robustness and excellent performance of track continuity.关键词：fuzzy clustering;probability hypothesis density (PHD) filter;data association;track continuity2|3|7更新时间：2025-07-16
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