最新刊期
卷 38 ， 期 6 ， 2010
- 摘要：The precession parameters of ballistic targets are of great importance to warheads and decoys discrimination.Based on dynamic ISAR image sequence,this paper analyzes the specialties of scattering and ISAR imaging of spatial ballistic targets.The history of posture changing is deduced.And a method for posture difference evaluating based on image registration is proposed.Moreover,equal interval registration method is adopted to avoid
singular registration.Precession parameters are extracted based on posture difference curve.And the extraction process is presented detailedly.Experimental results show that the posture difference can be estimated correctly and the precession parameter estimation has good precision.关键词：ballistic target;precession;ISAR image;registration;feature extraction2|2524|8更新时间：2025-07-16 - 摘要：A dynamic task scheduling approach based
on particle swarm optimization (PSO) and simulated annealing (SA) technique for
wireless sensor and actuator networks is proposed to solve the execution proble
m of tasks collaboratively among actuators.The purpose of approach is minimizin
g the maximum response time in the actuators subject to residual energy constrai
nts and schedule execution period of each task operation within given time.Simu
lation results have shown that the proposed hybrid approach is of high convergen
ce speed and good performance between task response time and balancing the energ
y dissipation among actuators.关键词：wireless sensor and actuator network;task scheduling;particle swarm optimization;simulated annealing2|1741|12更新时间：2025-07-16 - 摘要：An algorithm for effective channel
order estimation (NECOE) is proposed.Based on subspace decomposit
ion,the space spanned by the eigenvectors of the autocorrelation matrix of the
measurement vector can be divided into “signal” subspace and “noise” subspac
e,a special matrix Gv is constructed by “noise” subspace,and a new theorem is derived and proved,which indicates that the special matrix has only one zerovalued eigenvalue,if and only if La is equal to the effective channel order.Based on the new theorem,the channel order is estimated by modifying the dimension of “noise” subspace and judging the singularity of matrix Gv.
Simulations results show that the novel algorithm has perfect performance for low SNRs,especially when the channel impulse response has small head and tail taps.关键词：blind equalization;subspace decomposition;channel order;Gv matrix2|1722|7更新时间：2025-07-16 - 摘要：For the robust adaptive beamforming problem of the space distributed signal models,a robust beamforming algorithm for general signal models is proposed.
Not only the closeform solution is found,but also the optimal performance improvement can be obtained.Therein,the relationship of the proposed algorithm with the traditional diagonal loading is analyzed,and the optimal loading level can be computed exactly,the solution with the optimal negative loading has the optimal performance.The last simulation attests its correctness and effectiveness,and
indicates that the optimal weight vector is only determined by the given received data and the unknown mismatch,and is independent of the mismatch constraint parameter,but the mismatch constraint parameter is the adjective parameter for the optimal weight computing.
关键词：adaptive beamforming;worstcase performance optimization;general signal models;negative diagonal loading2|1406|10更新时间：2025-07-16 - 摘要：A global localization and selfdocking method for mobile robot is presented.The method is composed of two stages:during the offline stage,SIFT (scale invariant feature transform) algorithm is used and a DDBBF (double direction best bin first) matching method is presented to implement the 3D reconstruction of vision features;an ES (evolution strategy) and adaptive re-sampling scheme were applied in RBPF (RaoBlackwellized particle filter) to implement the mobile robot SLAM (simultaneous localization and mapping).In the online stage,the global docking station is recognized through HMM (Hidden Markov Model) based methotd,he global metric pose and location of the robot are estimated by a RANSAC algorithm;and then an epipole servoing method is presented to dock the robot precisely.Experiment results carried out with a real robot in an indoor environment show the superior performance of the proposed method.2|1635|7更新时间：2025-07-16
- 摘要：A novel design scheme of phaselocked system of hydrogen maser frequency standard is proposed based on equivalent phase comparison frequency.Using the regularity of the variation of phase difference between frequency signals,linear phase comparison is possible without the same frequency between them,namely different frequency phase comparison.If different frequency phase comparison is used in PLL of the hydrogen maser frequency standard,through suitable choice of the equivalent phase comparison between reference signal and locked signal,we can directly compared phase between different frequency signals and obtain very high phaselocked precision.Experimental results show that the design scheme is advanced and scientific.Its phaselocked precision can reach the order of magnitude of 10-12/s.Compared to traditional phaselocked system of hydrogen maser frequency standard,the system is high in phaselocked precision,simple in circuit structure,small in additional noise,and can be direct phase comparison between different frequency signals.Thus it is widely used in navigation positioning,space technology, communication,metrology,precise timefrequency measurement and control and so on.关键词：group periods;different frequency phase comparison;group phase shift;different frequency phaselocked;hydrogen maser frequency standard2|1405|5更新时间：2025-07-16
- 摘要：A novel method is proposed for multiuser carrier frequency offset (CFO) estimation for orthogonal frequency division multiple access (OFDMA) uplink with generalized carrier assignment scheme.The base station is equipped with arrayantenna.Each user’s CFO and direction of arrival (DOA) can be estimated by the DOAMatrix method utilizing the rotation invariance of the spacedomain snapshot matrix.The method is still effective even in fully loaded system with all subcarriers allocated to users,and the computational complexity can be adjusted dynamically according to the system load.Simulation results illustrate the high performance of the proposed algorithm.关键词：orthogonal frequency division multiple access;carrier frequency offset estimation;arrayantenna;rotation invariance2|1076|1更新时间：2025-07-16
- 摘要：A computeraided tuning method based on machine learning is proposed in the paper.In the method,an effect model that reveals the relationships between the tunable screws and filter electrical performance is firstly developed by using a kernel algorithm,according to the data sets from tuning experience of technician.Then,a tuning procedure of filters is constructed by using the developed machine learning model.Finally,some experiments are carried out,and the experimental results confirm the effectiveness of the method.The approach is particularly suited to the computeraided tuning of volumeproducing filters.关键词：cavity filters;computeraided tuning;machine learning;tunable screws;tuning experience3|1650|0更新时间：2025-07-16
- 摘要：For high squint DBS imaging on a constant acceleration movement platform,range walk correction and quadratic phase error compensation are challenging issues.According to these two issues,this paper proposes a DBS imaging algorithm,which corrects the range walk based on the Radon transform and compensates the quadratic phase error based on the Radon ambiguity transform.And the spatial adaptability of the algorithm is also analyzed.It is easy to understand,shows good performance and needs no prior knowledge of the movement parameters and the look angle of the radar platform.Simulation results demonstrate the validity of the method.关键词：radar imaging;Doppler beam sharpening (DBS);high squint;constant acceleration movement;Radon transform(RT);Radon ambiguity transform(RAT)2|1331|7更新时间：2025-07-16
- 摘要：Remote sensing image fusion based on support vector value contourlet transform is researched in this paper.Firstly support vector value filter and directional filter bank are rationally matched to construct support vector value contourlet transform,which has advantages of shift invariant、good generalization and strongly catching singularity ability.Then the transform is used to decompose multisource remote sensing images at multiscale、multidirection and multiresolution.At different levels,images are fused based on regional energy and regional contourlet contrast.Experiments show that,when remote sensing images being fused by using this transform,spectrum is effectively preserved while space resolution being not reduced.关键词：image processing;image fusion;remote sensing image;support vector value contourlet transform2|1721|6更新时间：2025-07-16
- 摘要：The translation invariant analytic contourlet transform with low redundancy is proposed. In this transform, the circular symmetric filter banks decomposes image into multi-resolution detail subbands and one low-frequency subband, then the detail subbands are processed by Hilbert transform to generate two dimensional analytic signals. At last, the analytic signals are decomposed by directional filter bank to implement analytic contourlet transform with multi-scale, multi-direction, and translation invariant property. The real part and imaginary part of the analytic contourlet basis functions resemble Gabor wavelet, and conform well to the human visual system. The experiments show that the analytic contourlet transform can achieve higher performance in image denoising and compressed sensing.关键词：contourlet transform;analytic signal;translation invariant;compressed sensing4|2553|21更新时间：2025-07-16
- 摘要：A novel approach to generate test data for multiple paths coverage is presented. First, the program under test is expressed as a binary tree, and the target paths are encoded into a binary string using Huffman coding; then, genetic algorithm is employed to generate multiple test data, an individual’s fitness is the degree of the traversed path matching the target paths. The proposed approach is applied to 4 benchmark programs, and compared it with previous approaches. The results show that the proposed approach needs small amount of calculation and has high efficiency in generating test data.关键词：software testing;path coverage;test data;genetic algorithms;Huffman coding4|1579|15更新时间：2025-07-16
- 摘要：The adaptive resource allocation’s multilayer multiobjective model for multiuser multiserver power-line communication systems is analyzed with the various restrictions. Based on the fast nondominated sorting genetic algorithm II, an improved resource allocation genetic algorithm with rate or power adaptation for single and multiple objective optimization is proposed, which firstly assigns resource for RT user by using the improved multiple objective genetic algorithm so as to obtain all Pareto nondominated solutions, secondly computes the system’s remainder resource for every Pareto solution and assigns them for NRT user by using the improved single objective genetic algorithm, lastly searches the global optimal scheme from all resource allocation schemes. The algorithm is tested in the typical power-line channel environment and the simulation results indicate that it has better performances and satisfies betterly the multiple aims of multiuser resource allocation.关键词：power-line communication;resource allocation;multilayer multiobjective optimization;genetic algorithm2|1456|0更新时间：2025-07-16
- 摘要：A one-dimensional Poincaré map for the forward traveling voltage wave at the left end of Josephson junction electromagnetic system with lossless transmission line is derived. The stability at fixed point of the map is analyzed based on nonlinear dynamics theory. The bifurcation diagrams with voltage reflex coefficient as parameter are obtained through numerical computation and the dynamic evolutive process of the system is analyzed in detail. Numerical results show that under certain parametric condition complex nonlinear dynamical behaviors exist in the electromagnetic system, such as bifurcation, chaos, coexisting periodic attractors, coexisting chaotic attractors, and coexisting periodic-chaotic attractors.关键词：Josephson junction electromagnetic system;Poincaré map;bifurcation;chaos;coexisting attractors2|1685|3更新时间：2025-07-16
- 摘要：A self-calibration algorithm (SAL: self-calibration algorithm for L-shaped array) is presented for L-shaped array in the presence of mutual coupling. The proposed algorithm utilizes special mutual coupling characteristic of L-shaped array to decouple the signal source information (DOA) and coupling coefficients of antenna array so that two kinds of parameter estimations can be realized without any calibration sources. It not only calibrates mutual coupling inside sub-arrays, but also calibrates mutual coupling between sub-arrays. Compared with conventional self-calibration algorithm based on iterative alternating minimization technique, the proposed algorithm transforms joint estimation problem about DOA and mutual coupling coefficients into cascaded estimation problem, which means that we firstly estimate DOA by searching spectrum peak, and then estimate coupling coefficients so as to avoid huge computation because of multi-dimensional search and global convergence problem due to iterative. Simulation results demonstrate that the proposed self-calibration algorithm is characteristic of high accuracy and little computation.关键词：L-shaped array;DOA estimation;mutual coupling;self-calibration2|1360|9更新时间：2025-07-16
- 摘要：The UTD method applied to arbitrary surfaces is studied in this paper where the NURBS technique is introduced to construct electrically large targets and on the basis of the ray-tracing work done before, the calculation of ray fields including reflected ray field and creeping ray field are given. Combining the definition of NURBS with basic principles of differential geometry, parameters used in formulas are solved by numerical means while the line integral is expended by definition. Aiming at analyzing electrically large targets with arbitrary shapes, method presented, which doesn’t need much calculation resources and possesses higher precision, can be applied not only to typical analytical objects but also to arbitrary surfaces and examples of application are given.关键词：non-uniform rational Bezier spline(NURBS);UTD;ray fields;pattern2|1245|0更新时间：2025-07-16
-
SAR Image Despeckling Based on the Estimation of Speckle Variance in Nonsubsampled Contourlet Domain
摘要：Synthetic aperture radar (SAR) images are inherently degraded by speckle noise, that severely affects the image qualities and makes the automatic interpretation of the image data very difficult. Combine the SAR image statistical property with the favorable capability of nonsubsampled contourlet transform on describing SAR images detail information, a novel SAR image despeckling method is presented. We estimate the speckle variance in each high-frequency directional subband. The local directional statistical information and the estimated speckle variance is used to classify the nonsubsampled contourlet transform coefficients as signal and noise coefficients. The SAR image despeckling is implemented by retaining signal coefficients and restraining noise coefficients. Experimental results demonstrate that the proposed despeckling method can preserve detail information effectively and reduce the speckle noise at the same time.关键词：SAR image despeckling;nonsubsampled contourlet transform;wavelet transform2|1831|8更新时间：2025-07-16 - 摘要：To reduces the design task and time of CICC(cable-in-conduit conductor) in the superconducting magnet, a simulation design idea based on stability and strain is presented. The effect of strain on critical current density is investigated, and a corresponding quantification method is given. A model of numerical simulation design of CICC is built, and the structure of CICC is designed by the model. The numerical simulation design coincides well with the engineering design.关键词：strain;cable-in-conduit conductor;numeric simulation;stability;design for CICC2|1411|0更新时间：2025-07-16
- 摘要：Since the control state of wheel robots from encoder is colored noise in the mechanical manufacture, the traditional simultaneous localization and map building algorithms are on longer applicable. In the paper, an algorithm of colored-state-noise SLAM is proposed. Nonlinear process model is linearized and colored-state-noise model is converted into Gauss white noise one by augmenting dimension of state. The integral algorithm procedure follows the recursive order of prediction, observation, data association, update, mapping to have simultaneous localization and map building. MonteCarlo simulation results show that the proposed algorithm has higher estimate precision than those of EKF-SLAM algorithm and Fast-SLAM algorithm in colored process noise covariance.关键词：colored state noise;wheel robots;simultaneous localization and map building;estimate precision2|1304|7更新时间：2025-07-16
- 摘要：Estimation on connectivity of the end-to-end path is well done by employing the dynamic analysis on link state information. The proposed routing model computes for each node pair the predictable delivery ratio of packets transferring which happened in the most recent time slots. Each node evaluates the different relay strategies by computing the combined predictable delivery ratio, and picks the optimal strategy for packets forwarding. Simulation results show that high packet delivery ratios can be achieved while the duplicate packets remain in a small number.关键词：mobile ad hoc networks;routing;predictable delivery ratio2|1165|0更新时间：2025-07-16
- 摘要：This paper puts forward to the concept of loosely and tightly grouping-cascaded BP network model to solve the training problem of high dimension BP neural network with limited small samples. After defining the equivalence definition and relative theorem of BP neural network, the grouping-cascaded model which is proved to be equivalent to BP network is constructed and the required number of training samples between them is compared. Then this method is applied in the evaluation of the network security. Finally, the feasibility and validity of the proposed grouping-cascaded BP network model is verified with simulation results.关键词：grouping-cascaded network model;BP neural networks;equivalent;small samples2|2125|2更新时间：2025-07-16
- 摘要：In the researches of discrete-time two-person stochastic differential games, the uniform and exact descriptions on information pattern are absent. To solve this problem，the mathematical definitions of information pattern and other related concepts are addressed in this paper firstly, by introducing Witsenhausen’s concepts about information pattern to the discrete-time two-person stochastic differential games. Then the properties of several typical information patterns and the structures of optimal control law of differential game under these information patterns are strictly proved. The concepts and theorems of the paper provide an important theoretical tool for the researches of discrete-time two-person stochastic differential games.关键词：stochastic differential games;information pattern;state estimation;optimal control;control law2|1198|1更新时间：2025-07-16
- 摘要：In this paper, a miniaturized frequency selective surface (FSS) is presented. In this kind of FSS, each periodic cell consists of a ring slot loaded with ceramic chip capacitors for reducing the cell size, and Faraday Cage structure is introduced to eliminate the disturbance between unit cells. The loaded FSS has been analyzed and empirical formulas for calculating resonance frequency in the range of 1~4GHz is presented. The miniaturized FSS with high transmission at 2.45GHz has been designed by the empirical formulas. The dimension of the proposed FSS is miniaturized to 34 percent in comparison with the traditional FSS. The simulation and experimental result indicate that the loaded FSS has good polarized characteristic and very good stability to oblique incidence.关键词：frequency selective surface;loaded;faraday cage;finite difference time domain2|1456|3更新时间：2025-07-16
- 摘要：In this paper, a new range-dependence compensation method for bistatic stap is studied. The flaw of Registration Based range Dependence Compensation (RBRDC) is analyzed, including the algorithmic complication and unnecessary errors. A new method base on transformation field is proposed. Simulation shows the advantage of the new method.关键词：bistatic radar;ground clutter;spectrum of space-time;range-dependence compensation2|874|1更新时间：2025-07-16
- 摘要：This paper presents an adaptive signal decomposition method. The core of the proposed method is to decompose the observed signal into a series expansions of waveforms which best matches the signal local structures. These waveforms are calculated by the nonparametric waveform estimation method. With the proposed method, the adaptive adjustment of template signals makes it unnecessary for the method to require priori information, so that it has better flexibility and adaptability in practical applications. The performance of the proposed method is confirmed by testing its adaptability and convergence. The extraction results of simulation signals are compared with which of the feature extraction method based on the traditional MP decomposition and EMD decomposition, thus verified the feasibility and effectiveness of the proposed method farther.关键词：signal decomposition;nonparametric basis;adaptive template signal2|1279|3更新时间：2025-07-16
- 摘要：For the problem of electromechanical separation and negligence of feed position error in reflector antenna design. From the angle of electromechanical coupling, the distortion of main reflector and position error of feed were introduced in the formula of antenna’s far field pattern. So the effect of structure parameters including feed support structure on the main electrical parameter (such as gain, side lobe, beam width, pointing accuracy) could be researched. Due to the proposed formula, a new electromechanical coupling optimization model of whole antenna including feed support structure parameters was proposed. Simulation was done via an 8m reflector antenna. Result shows that the optimization model is more efficient than tradition ones. Finally the proposed optimization model is applied to a 40m reflector antenna with good results.关键词：reflector antennas;electromechanical coupling;optimization model;feed position error2|1835|7更新时间：2025-07-16
- 摘要：The existing methods for misuse detection of information systems are restricted because of their own limitations, such as unable to detect new kinds of misuse and need the knowledge of potential misuses. A hidden Markov model (HMM) based method is presented to detect the misuse of resource in information systems. In the HMM model, the file folders containing sensitive information are taken as the model states and the user operations as the model observation symbols. Baum-Welch algorithm is adopted to determine the model parameters. The behavioristic profiles of the insiders are determined by the HMM model and used to detect malicious actions. The simulation results show the effectiveness and adaptability of our method.关键词：information system;hidden Markov model (HMM);resource misuse;insider threat detection2|1321|2更新时间：2025-07-16
- 摘要：
Triangle Size Effect (TSE) is one of the major sources of wind estimate bias in SA mode for MF radar. So the size of antenna arrays must be considered in the design of MF radar. The effect of TSE on MF radar is analyzed from the following two aspects: (1) How the size of antenna arrays influence the error of cross-correlation function maximum; (2) How the size of antenna arrays influence the acceptance rate. The results show that the size of antenna arrays should be smaller than the patterns size to ensure the high acceptance rate. When the above condition is satisfied, the larger size of antenna arrays, the lower wind estimates bias. Finally, how to choose the appropriate size of antenna arrays is discussed.
关键词：medium frequency radar;triangle size effect;full correlation analysis3|1019|1更新时间：2025-07-16 - 摘要：Reliability of Traveling Wave Tubes (TWTs) are crucial for operation of many armaments. However, due to the complexity and expensiveness of TWTs, the way to precisely evaluate their reliability under small sample size is still the problem to face. In this way, prior information, such as expert experience and historical data, can be used to enhance the estimation precisions. With a fuzzy prior distribution construction method for TWTs introduced, based on fuzzy membership functions, prior information can be effectively merged with test data using Bayes method. Reliability evaluation for some satellite TWTs shows that, the precision can be enhanced notably for data with small samples or high truncation levels by using Bayes estimation with normal fuzzy prior distributions. And the estimation can be modified by increasing test information. Furthermore, the bandwidth of the normal priors can be used to adjust the proportion of prior information within the post-Bayes distributions.关键词：traveling wave tube;reliability evaluation;small samples;Bayes method;fuzzy prior information2|1465|1更新时间：2025-07-16
- 摘要：Topology control aims to maintain network connectivity and reduce energy consumption for Ad hoc networks using steered beam directional antennas. To derive analytical expressions to determine the critical transmission range and neighbor number K, we employ quadrat statistical methods. A distributed neighbor-based topology control approach, referred to as the DK-Neigh, is proposed to maintain the outdegree of every node equal to or slightly below a specific value K. The approach can build the resulting communication graph with high probability connected. Extensive simulations are carried out, which show that the DK-Neigh is to achieve a high probability (more than 96%) of connectivity. If width of beam is smaller than 60, average energy cost of nodes is reduced at least 15% than the topology control protocol K-Neigh using omni-directional antennas. Simulations show the DK-Neigh is more energy-efficient while maintaining network connectivity.关键词：Ad Hoc networks;directional antennas;topology control;energy efficient2|1164|2更新时间：2025-07-16
- 摘要：The nonlinear chirp of laser reduces the range resolution of synthetic aperture imaging ladar. The compensating algorithms by establishing reference path are developed. An equal delay theory to compensate nonlinear chirp phase errors and asynchronous trigged phase errors is proposed, including three methods: establishing matched target LO path, establishing reference path and twice coherent detection, establishing reference path and phase shifting calculation. The mathematical flow of the algorithm is established. The simulation of the airborne synthetic aperture imaging ladar model validates the feasibility. The characteristics of three methods are discussed finally.关键词：synthetic aperture imaging ladar;equal delay;nonlinear chirp signal;range resolution2|1117|7更新时间：2025-07-16
- 摘要：An integrated capacitive sensor with comb electrodes is researched and the electrostatic capacitance of its external electrons is analyzed using conformal transformation. The analysis expressions and physical model are built and simulated by Ansys. The calculation results based on the expressions are in agreement with the simulation results by Ansys. It shows that the theoretical model we have gotten is right. These expressions can be used in design and application of capacitive sensors with comb electrodes.关键词：capacitive sensor;electrostatic capacitance;external electrons;conformal transformation2|1493|1更新时间：2025-07-16
- 摘要：Having researched further into the NMŁ system(Nilpotent Minimum Łukasiewicz Logic), the strong completeness of NMŁ is discussed. Firstly,the properties of NMŁ-chain are studied and it is proved that each NMŁ -chain is partially embeddable into . Secondly, the finite strong completeness theorem of NMŁ is investigated by means of the partially embeddable property. Finally, it points out that NMŁ does not enjoy the strong completeness about infinite theory.关键词：fuzzy logic;NMŁsystem;partially embeddability;strong completeness2|961|4更新时间：2025-07-16
- 摘要：A 155Mbps QAM demodulator is designed for digital millimeter-wave communication. A novel parameter named Signal Resource Quantity (SRQ) incorporating peak and average power ratio, demodulation threshold and bandwidth was introduced to find out the best order of QAM for high-speed millimeter-wave communication. The 4~64QAMs win in 4~1024QAMs according to their SRQs. How gain deviation of AGC and carrier leakage affect the demodulation performance were studied. A zero-jitter timing recovery detector was implemented by the theories of pre-filtering Nyquist raised sine signal with small roll-off factor. An improved PFD carrier recovery algorithm with adaptive power threshold was proposed to avoid wrongly capturing constellation points in the case of high-order QAM. The design has been applied to a millimeter-wave link successfully, and the algorithms work robustly. The demodulation loss was less than 2dB when the BER was equal to 1E-8.关键词：QAM;millimeter-wave;demodulator;timing recovery;carrier recovery2|1549|0更新时间：2025-07-16
- 摘要：The feature extraction is one of the key steps and difficulties for Synthetic Aperture Radar(SAR) Auto Target Recognition. This paper proposes a novel method based on Non-negative Matrix Factorization for SAR images feature extraction and target recognition. In order to make full use of local spatial structure information for target feature extraction to achieve target recognition, it takes the form of non-negative weighted combination of basis vectors to construct SAR target images. First, the level set SAR image segmentation method is adopted to get the target image from noisy SAR image, then, after non-negative matrix factorization, the resulting weighted vectors are regarded as the feature vectors of the target images, and finally, Fisher Linear Discriminant is considered as a classifier to perform target recognition. The method is used for recognizing three-type target motels in MSTAR database. Compared to other classical methods, the experimental results show that the new method is an effective approach for SAR images feature extraction and target recognition.关键词：SAR;target recognition;NMF;Fisher Linear Discriminant2|2005|11更新时间：2025-07-16
- 摘要：This paper presents a new minimum mean squared “normalized-error” (MMSNE) beamforming technique, against arbitrary unknown heavy-tailed impulsive noises. This new beamformer aims to minimize the “normalized error” between the desired signal and the the beamformer’s output. This normalized error is defined in terms of the instantaneously adaptive infinity-norm snapshot-normalized data. This new MMSNE beamformer outperforms the fractional lower order moments (FLOM)-beamformer with these advantages: (1) simpler computationally with a closed-form solution, (2) needing no prior information nor estimation of the impulsive noise’s effective characteristic exponent’s numerical value, (3) applicable to a wider class of heavy-tailed impulsive noises, (4) providing lower estimation error, and (5) offering better interference-rejection.关键词：array signal processing;beamforming;Fractional Lower Order Moments;impulsive noise2|1737|6更新时间：2025-07-16
- 摘要：A feedback mechanism of the Page Test is proposed to establish. From the aspects of the estimation of SNR on square output of the matched filter, normalization, and the gate calculation, the algorithm and information feedback flow are researched. We also study the effect of SNR mismatch on the detection performance and the effect of gate-SNR design on the false alarm performance. The experiment on the sea shows that the performance of the Page Test with sound field prediction and feedback mechanism is improved evidently when processing lower frequency signals with lower SNR, and its performance is better than the conventional space-time background equalization algorithm.关键词：the page test;active sonar;feedback2|1107|5更新时间：2025-07-16
- 摘要：The design problem of state feedback robust controller is concerned for a class uncertain Markov jump linear system which mode is not available completely. And the controller guarantees the closed-loop steady-state variance to be less than given upper bounds based on linear matrix inequality (LMI) method, system variance has been analyzed and conditions of existence of such controllers are proposed and proved. A parameterized representation of a set of desired controllers is characterized in terms of the feasible solutions to the LMI system. Finally, the simulation results show the effectiveness of the method.关键词：variance constraint;H∞ performance;Markov jump system;linear matrix inequality4|1040|1更新时间：2025-07-16
- 摘要：To solve the particles impoverishment and the real-time decline caused by re-sampling and the proposal distribution optimization, a novel particle filtering algorithm based on generalized unscented transformation is proposed. The generalized unscented transform and the one-step state prediction and observation update of Kalman filter are introduced to realize the optimization of state estimation by the latest observation information. Then, by means of combining the improved algorithm with interacting multiple model, the interacting multiple model particle filtering algorithm based on generalized unscented transformation is proposed. The theoretical analysis and experimental results show that the new algorithm is close to the standard particle filter in computational complexity and superior to the standard particle filter and its improved algorithms in precision.关键词：hybrid system;particle filtering;interacting multiple model;generalized unscented transformation2|1257|6更新时间：2025-07-16
- 摘要：This paper investigated the early detection problem of multiple moving targets in MIMO radar systems using the track-before-detect (TBD) techniques. Based on the binary generalized likelihood ratio test (GLRT) with a priori known number of targets, a suboptimum multi-target TBD algorithm using successive-target-cancellation and polar Hough transform (STC-PHT) was proposed, and false alarm probability and detection probability formulae were derived. Compared with previous multi-target TBD algorithms, the new proposed algorithm has low computational complexity, no need for the prior information of the number of targets, and avoids the implementation of multiple hypothesis tests when the number of targets is unknown. The simulation results show that the new proposed algorithm can effectively improve the detection performance of MIMO radar at low signal-to-noise ratio.关键词：MIMO radar;Successive-Target-Cancellation;Polar Hough Transform;track-before-detect;generalized likelihood ratio test4|1877|13更新时间：2025-07-16
- 摘要：A new method for joint estimation of ranges direction-of-arrivals(DOA’s) and frequencies of multiple near-field sources without pairing parameters is presented. A new matrix has been obtained from the transformation of the constructed four-order cumulant matrix. The parameters are directly given by the eigenvalues and eigenvactors of the new matrix. Compared with several existing methods, the proposed methed can achieve automatic pairing. Finally, the simulation result are presented to validate the performance of the proposed method.关键词：near-field source;cumulant;DOA estimate;range estimate;frequency estimate;automatic pairing2|1130|3更新时间：2025-07-16
- 摘要：For a given number of elements sparse linear array provides a larger aperture. However, it samples the incident signal non-uniformly, so the analytic expression of its peak sidelobes can’t be obtained by traditional FFT method. An analysis of side lobe structure of non-uniform sparse linear array based on lattice theory is presented. First, the array manifold lattice is modeled. Then the relationship between nearest lattice points and the peak sidelobes structure is investigated. Thus the problem of getting the sidelobe peaks becomes the problem of finding the nearest lattice points from the origin in array manifold lattice. This method can find the number and wavenumber vector with respect to peak side lobe whose gain is higher than the given gain precisely. Computer simulation results are presented to show its effectiveness and accuracy.关键词：non-uniform sparse linear array;lattice theory;peak side lobe structure2|1399|1更新时间：2025-07-16
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- 摘要：A nonparametric Wasserstein distance-based active contour model that is able to utilize image histogram information in local region is presented. To quantify the similarity between two regions, we proposed to compare their respective histograms using the Wasserstein distance; Due to a Gaussian kernel introduced, intensity information in local regions is extracted and embedded in model to guide the motion to overcome the difficulties in image segmentation caused by intensity inhomogeneities. In addition, the regularity of the level set function is intrinsically preserved by the level set regularization term to ensure accurate computation and avoids expensive reinitialization of the evolving level set function. Experiment results prove that our model segments texture images with intensity inhomogeneity effectively.关键词：image segmentation;Gaussian kernel;Wasserstein distance;histogram2|1491|5更新时间：2025-07-16
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