最新刊期
卷 37 ， 期 3 ， 2009
- 摘要：Web services behavior is the key aspect to compatibility and consistency of web services,which can ensure correctness and reliability in web services choreography.But few methods can conduct the trade-off between expressiveness and amenability of efficient verification,this paper gives a better answer to solve the problem.It constructs services behavioral type discipline based on extended the Martin-Lf's type theory(for short,MTT) which supports a type-theoretic formulation of services behavior structured patterns,so that services behavior in a distributed system can be verified by type checking.Then,the type rules for subtype,duality,compatibility and consistency of web services behavior are discussed.The deductions are given to show that how to verify the consistency between behavior of vendor and behavior of vendor-s.Finally,the complexity of the deduction is given.关键词：web services behavior;consistency;compatibility2|1193|17更新时间：2025-07-16
- 摘要：A proxy signature scheme enables a proxy signer to sign messages on behalf of an original signer.Proxy signature schemes have been shown to be useful in many applications.A Proxy Signature Scheme from Bilinear Pairings is proposed.It is proved that the scheme is secure in the random oracle model and more efficient than Zhang's scheme.关键词：proxy signature;bilinear pairings;provably-security2|1294|5更新时间：2025-07-16
- 摘要：An algorithm of robust linear processing for the downlink multiuser MIMO system with imperfect known CSI is proposed.This algorithm uses stable channel statistics information about the channel mean and antenna correlation,to minimize the average value of the all user’s total mean squared error over stochastic channel under the transmitter sum power constraint.This algorithm does not exactly depend on instantaneous channel information,when CSI obtained by channel estimation is not perfect,the performance loss due to the CSI mismatch can be efficiently reduced.Simulation results demonstrate that the proposed algorithm effectively ameliorate the BER and average MSE due to the CSI mismatch.关键词：multiuser MIMO;downlink;robustness;imperfect CSI2|944|1更新时间：2025-07-16
- 摘要：The roundtrip propagation loss of spherical wave is remarkable for the near-field imaging of large and complicated targets.The spherical back-projection(SBP)algorithm was modified by introducing a compensation factor for the roundtrip propagation loss.The magnitude precision of the image is increased by the modified algorithm.In the same sense,the spherical convolution back-projection(SCBP)algorithm was also modified.Comparisons of the numerical simulating between the modified SBP and the modified SCBP indicate that the precisions of the two algorithms are almost the same but the computation cost of the modified SBP is reduced.关键词：near-field imaging;algorithm;propagation loss;spherical back-projection;spherical convolution back-projection2|1102|0更新时间：2025-07-16
- 摘要：Traditional radar makes use of single polarization antenna,which doesn’t utilize the polarization characteristic of target and interference.This paper firstly introduces the polarization principle of anti-jamming and analyzes its performance.A new type of crossing polarization antenna array is presented.Then the polarization performance on this antenna array is analyzed.Simulation and test results indicate that this antenna array not only has the better anti-jamming performance but reduces the equipment quantity,which will be widely used in future.关键词：space anti-jamming;polarization anti-jamming;crossing polarization antenna array2|1374|13更新时间：2025-07-16
- 摘要：Radar high-resolution range profile (HRRP) is sensitive to amplitude-scale,which is overcame through simply normalizing the amplitude-scale to unit energy by most available HRRP radar automatic target recognition (RATR) approaches.In light of the tangent distance,we propose two algorithms to improve HRRP recognition performance using amplitude information.Experiments based on measured data shows our algorithms have a larger average recognition rate than that of the regular method by about 5 percentage points.关键词：high resolution range profile(HRRP);amplitude-scale sensitivity;radar automatic target recognition3|982|2更新时间：2025-07-16
- 摘要：Classic SVDD classifiers,which use distance measures,have lower recognition rate than normal two-class SVM classifiers.After analyzing the causes,a new measure is proposed,which can represent the more essential relationship between samples and categories.And then,a multi-level SVDD is proposed.The experiment on real one-dimensional range profiles data shows that,the multi-level SVDD reserves the lower complexity,higher expansibility and fewer requirements to sample size,ERs are reduced effectively,CR is increased even to the level of two-class SVM classifiers.关键词：pattern recognition;SVDD;multi-level architecture;multi-class classification2|980|14更新时间：2025-07-16
- 摘要：This paper presents processing algorithm for wide-swath spotlight SAR data processing based on spectram analysis (SPECAN).The first step of the proposed algorithm implements SPECAN processing to range dechirped signal.This operation can eliminate azimuth spectrum folding effect and migrate and scale the azimuth data support.Then compensates azimuth quadratic phase and recovers the ideal data support via appropriate interpolation.Finally focuses image with a two-dimensional inverse Fourier transform.Discussed and gave the restriction on the pulse repetition frequency (PRF).Experiments confirm the validity of the presented algorithm.关键词：radar imaging;spotlight SAR;spectral analysis (SPECAN) processing;wide-swath image2|2053|6更新时间：2025-07-16
- 摘要：One-dimensional Otsu’s method is a classical threshold segmentation method.Following this thought,Li and Lee proposed a threshold segmentation method based on cross-entropy.A two-dimensional cross-entropy linear-type threshold segmentation method and its fast recursive formula were proposed based on the explanation and demonstration of Li and Lee’s method and corresponding with the two-dimensional Otsu’s linear-type threshold segmentation method.Compared with the two-dimensional Otsu’s linear-type threshold segmentation method,the new method can be better adapted to the cases that the variance between the object and background is large.It is shown that the new method is an available threshold selection method.关键词：threshold segmentation;Otsu’s method;cross-entropy2|1667|13更新时间：2025-07-16
- 摘要：Efficient modeling of array manifold is the essential prerequisite for the array signal processing.Due to the variable curvature of the platform and different orientations of elements,the most serious challenge faced in the modeling of array manifold for conformal array antenna is the element polarized pattern modeling in the global referenced coordinates.A uniform frame of the rotation transformation of the global Cartesian coordinates to the element local Cartesian coordinates is first established with the help of the Euler rotation.The rotation transformation of the polar coordinates of the global array to the local elements and the polarized pattern rotation of the local to the global coordinates are realized subsequently.The modeling method proposed is verified with the simulation of inherent shade effect of circular cylinder conformal array antenna.关键词：conformal antenna;array antenna;array manifold;Euler rotation2|2445|34更新时间：2025-07-16
- 摘要：Characteristics of the nonintertia fast directionality,easily form multiple beams of phased array radar antenna make it have more function than the conventional radar.In this article,both CPS scanning pattern and IPS scanning pattern are analyzed.An interlaced beam multiplexing scanning method based on IPS mode is established,which is fit for the weather phenomena with larger spectral width.After the shortcomings of presented Doppler weather radar VCP11 mode are analyzed,its scanning methods are improved,accordingly,the ideal scanning mode is derived,that is,three beams scanning is used in pitch at the same time.This scanning mode can reduce remarkably scanning time than using single beam scanning.关键词：phased array weather radar;scanning strategies;contiguous scanning;beam multiplexing;multi-beam2|1092|2更新时间：2025-07-16
- 摘要：The perfect punctured array pairs are used in a zero correlation zone (ZCZ),and then a construction method for ZCZ array pairs set is presented.The general construction method of ZCZ array set was based on perfect array,but the proposed construction method is based on perfect punctured array pairs and orthogonal matrix,ZCZ punctured array pairs set with certain volume and zero correlation zone can be synthesized through interleaved transformation when suitable shift sequences are selected.The existent range of perfect punctured array pairs is so wide that they can improve the volume limitation of perfect period correlation array.So with the proposed method,ZCZ punctured array pairs set have larger capacity of ZCZ array set,which can satisfy requirements of engineering applications.关键词：perfect array pairs;ZCZ;interleaved technique;correlation function2|721|6更新时间：2025-07-16
- 摘要：A Ku-band rotating,range-gated,fanbeam spaceborne scatterometer and its main parameters are described in this paper.This scatterometer is designed for a polar-orbit satellite with an orbit height of 500km.By simulation,the wind retrieval qualities with different antenna types are compared;and then two important parameters of the antenna,the two-way antenna gain and the half power beam-width in the range direction,are optimized,for an expected swath width of more than 1000km.It is concluded that the two-way antenna gain should be no less than 51.5dB,and -3dB beam width along the range direction (the elevation direction) is about 25degree.The results show that this new kind of scatterometer has better performance in wind retrieval compared with the spaceborne pencil-beam radar scatterometer,such as SeaWinds.Especially,the quality of retrieved wind direction can be improved significantly by this new system,under high wind-speed conditions.关键词：fanbeam;scatterometer;wind retrieval;noise;Figure-of-Merit (FoM)2|1222|3更新时间：2025-07-16
- 摘要：The performances of least mean square (LMS) time delay estimator (TDE) are analyzed using biased and unbiased estimation methods.Then a modified LMS method based on Treichler’s γ-LMS algorithm is developed for unbiased estimation in the presence of white input and output noises,in which the input noise variance is simply obtained by the Euclidean geometric interpretation of the best approximation in adaptive filters without any a priori knowledge of the interference.With this estimated variance,the proposed bias-free LMS-TDE can iteratively eliminate the input noise effects and actually enhance the true peak,thus it can reduce the probability of anomalous peak in noisy environments at lower signal-to-noise ratio (SNR) levels.It gets rid of the assumptions that the input and output noise powers are the same or their ratio is known,or the signals are all white processes.Simulations and real data application are both provided to validate its effectiveness.关键词：bias-free time delay estimation;least mean square adaptive algorithm;performance evaluation3|1470|9更新时间：2025-07-16
- 摘要：A robust method for estimating the covariance matrix using the weighted pixels vector for the joint clutter rejection is proposed.Firstly,the pixels vector is weighted based on the value of the generalized inner product.Secondly,the locations of the ground moving targets are detected using the map of joint clutter rejection with three SAR images.Thirdly,the true locations and velocities of the targets can be obtained by the local interferometric method.Finally,the performance analysis is given.Without the threshold of the sample select and only one pixel image registration being required,the improved factor with the weighted processing is much higher than that with the unweighted processing and the improved factor of the jointed processing is better than that of the paired processing.The effectiveness and robustness of the proposed method are verified with the results of the measured airborne data.关键词：GMTI;clutter rejection;sample select;three-aperture SAR2|1295|8更新时间：2025-07-16
- 摘要：The novel delay-dependent global exponential stability criteria are proposed for fuzzy cellular neural networks with time-varying delay.By constructing a new Lyapunov-Krasovskii functional,the criteria expressed by the form of linear matrix inequality (LMI) are given.Compared with the previous literature,the signs of elements of weighting matrix are first considered.Thus,the obtain results are less conservative.Moreover,the restriction of the time derivative of time-varying delays is released in the proposed criteria.The simulations are given to show the effectiveness of the criteria.关键词：fuzzy cellular neural networks;time-varying delay;exponential stability;delay-dependent;linear matrix inequality (LMI)2|922|0更新时间：2025-07-16
- 摘要：In order to improve the performance of projection approximation subspace tracking (PAST) algorithm under impulsive noise environment,based on Alpha stable distribution as the impulsive noise model,a new cost function is proposed using the robust m-estimation method and then the robust PAST algorithm (RLM-PAST) is deducted based on the recursive least m-estimate.Because the robust m-estimation function suitable for the Alpha stable noise model is used,the proposed algorithm offers good performance against impulsive noise over the PAST algorithm in direction of arrival (DOA ) estimation.The simulation results show the efficiency of the proposed algorithm.关键词：recursive least m-estimate (RLM);Alpha stable distribution;direction of arrival (DOA) estimation;subspace tracking3|975|3更新时间：2025-07-16
- 摘要：For the problem of the frequency and 2D direction of arrive (DOA) united estimation of narrow band signal for wide band receiver,a novel quick method is proposed.First,the pre-estimation is used to get the pre-estimating DOA with reference frequency,then the space filtering method is used to make the match of the signal pre-estimating DOA with its frequency,and the corresponding frequency is used to adjust the pre-estimating DOA according to the characteristic of the antenna configuration,therefore,the precise signal frequency and its DOA are obtained at the same time.The last simulation indicates that the proposed method is correct and effective to estimate the frequency and DOA of narrow signal for wide band receiver.关键词：array signal processing;two dimension direction of arrive estimation;frequency estimation;wide-band receiver;space filtering2|1067|5更新时间：2025-07-16
- 摘要：Particle swarm optimization (PSO) algorithm is a new promising swarm intelligence optimization technology,and it has been extensively studied and applied because of its advantages of simpler theory,less parameters and better performance.However,each particle’s individual minimum has a low updating rate,which has been one disadvantageous factor to affect this algorithm speed and precision.In this paper,we propose a novel multi-step position-selectable updating PSO algorithm.This algorithm decomposes the standard PSO velocity single-step updating formula into three steps and selects the best one among the three resultant positions as the final updated position.This scheme refines each particle searching trajectory,increases the updating speed of individual and global minimums,and consequently improves PSO algorithm converging speed and precision without increasing the computing complexity.Six classical testing functions,including Sphere,Rosenbrock and so on,are used to verify the proposed algorithm in two ways:a fixed iteration number test and a fixed time length test.Large numbers of simulations show that the proposed algorithm is simple,robust,and efficient,and meanwhile it outperforms other four existing classical algorithms.关键词：intelligent optimization;particle swarm algorithm;multi-step position-selectable updating scheme2|1396|8更新时间：2025-07-16
- 摘要：Planar inductors downsize the inductor devices.The effect of radiation and scattering from the windings must be considered when the signal frequency reaches to radio or microwave bands.Electromagnetic radiation from PCB planar inductors is studied by wavelet method of moment.The current distribution in PCB inductors is evaluated by using Coifman intervallic scarlet as the base function and test function in the Mom.The radiation patterns of two circular PCB planar inductors are given finally.The coefficient matrixes are sparsified by applying wavelet-Mom,which decrease calculation time and save the computer sources.关键词：wavelet;PCB planar inductor;electromagnetic radiation;Mom2|1206|2更新时间：2025-07-16
- 摘要：A framework based on domain model and component composition is presented,in which domain models can be used to capture the static business requirement,describe the static relationship between two business objects.The domain application framework describes commonness and provides variety extension,in this extension all kinds of components can be integrated into the system.In this way,a new system can be built and the user requirements can also be needed.Results show the framework is capable of find the commonness and variety and make use of them,and the software quality can be improved.关键词：domain model;component composition;domain framework2|1350|2更新时间：2025-07-16
- 摘要：This paper proposes the optimal timing by maximizing signal-to-interference-plus-noise ratio (SINR) for hexagonal multicarrier modulation (HMM) over doubly dispersive channels.An iterative optimal timing algorithm is derived and it comes out that there is an allowable error between the mean delay of doubly dispersive channels and the optimal timing.In addition,an approximate optimal timing synchronization method is proposed.The theoretical analysis and computer simulation results show that the proposed optimal timing is outperform the traditional timing method about 2~3dB in SINR while signal-to-noise ratio (SNR) is 30dB and the approximate optimal timing algorithm achieves a smaller mean square error (MSE) than 10-4 over doubly dispersive channels.关键词：hexagonal multicarrier modulation;optimal timing;timing synchronization;doubly dispersive channels2|879|0更新时间：2025-07-16
- 摘要：To study the effect of the surface errors on reflector antenna performance,a computational model including systematic distortions and random errors was presented.In the model,power pattern was given by the aperture-field method according to the relation between surface errors and the phase distribution of aperture plane.Then power patterns were simulated and it is shown that random errors work in every azimuth angles and systematic distortions generate grating lobes in a few angles,the location and level of grating lobes depend on the systematic distortions.Finally,the model was applied to a practical antenna with the diameter of 8 meters,the results show that the proposed model is valid.关键词：reflector antenna;surface errors;systematic distortions;random errors;performance2|2346|12更新时间：2025-07-16
- 摘要：By using the non-linear operators (such as Isomap,WordNet etc.),how to promote the traditional text information processing techniques to "understanding" level was discussed.Based on manifold analysis,the distribution of Chinese words in a continuous semantic space was primarily studied.Short messages clustering based on WordNet was investigated.Experimental results prove that these methods can reflect the internal relation of texts.关键词：semantic distance;manifold learning;words categorization;short message clustering3|1566|8更新时间：2025-07-16
- 摘要：Aiming at two-classes image pattern recognition problem of object and background,a novel image feature selection method,named immune antibody construction algorithm (IACA) is proposed,inspired by the biological immune antibody encoding principle.In the case of sample parameter estimation,IACA considers entropy to measure individual feature’s sensitivity of object and background,and defines the inclusion and complementary formulas about multi-features in set theory perspective.Guided by the minimum energy principle,image immune antibody construction rules and corresponding algorithm are proposed to find an optimized feature subset as object immune antibody.Furthermore,the dimension of the subset can be automatically determined without prior setting.The induction proved the result was the optimal feature subset.Data testing result shows that IACA has a lower computational complexity and error recognition rate than other methods,which has verified the superiority and the advanced nature of the method.关键词：image object recognition;feature selection;biological immune2|2206|0更新时间：2025-07-16
- 摘要：A class of maximum rate control-guaranteed rate(MRC-GR) algorithm is advanced,which can provide maximum rate control and guaranteed rate for flows simultaneously.For each network node employing scheduling algorithms belonging to MRC-GR,a method is presented to decide the upper bound and the lower bound on network end-to-end delay,and the delay bounds for source models conforming to token bucket and synchronization unit model are given.Simulations for worst-case fair weighted fair queueing with maximum rate control scheduling algorithm,which is an instance of MRC-GR,are carried on to validate the theoretic analysis.关键词：QoS control;delay;maximum rate control-guaranteed rate (MRC-GR) algorithm;guaranteed rate;maximum rate control2|959|0更新时间：2025-07-16
- 摘要：The diffusion model proposed by Perona and Malik is unstable.This will lead to the "staircasing effect" in image denoising.The lattice Boltzmann anisotropic diffusion model (LBADM) is proposed by introducing a medium between the nodes of the lattice based on the lattice Boltzmann isotropic diffusion model (LBIDM).The force represented by the forward diffusion process dominates in the LBADM.This means the Lattice Boltzmann model LBADM is stable.The experiment and discussion showed that our algorithm can overcome the staircasing effect of the P-M model well.Compared to the Perona and Malik’s isotropic diffusion model ,the lattice Boltzmann anisotropic diffusion model had higher peak signal-to-noise ratio.关键词：image denoising;lattice boltzmann model;P-M model;partial differential equation2|1420|11更新时间：2025-07-16
- 摘要：Empirical Mode Decomposition (EMD) is a decomposition algorithm which is used to analyze nonlinear and time-varying signal.Different from the traditional signal analysis method,the decomposition is data-driven and self-adaptive.A review work about the current development of one dimensional EMD and Bidimensional EMD is introduced.At first,some basic concepts and main algorithm ideas are described.Then the advantages and shortages of EMD are discussed.At the end of the paper,several problems which are waiting to be solved are listed.关键词：EMD;IMF;Hilbert transform2|4583|56更新时间：2025-07-16
- 摘要：Race exponent,a new evaluation criterion,is designed to measure the competitive capacity of individual,which develops from the idea of keeping population balance between fitness growth and individual diversity.In this paper,the race exponent is used to measure the absolute value of individual while ranking the population and its offspring according to it.The position parameter,generated by simulated annealing process,is used to measure the relative value of individual in rank.The weighted average value of race exponent and position parameter is used to be the survival probability of individual in rank,which can effectively control the selection pressure of population in iteration and keep population structure reasonably.The simulation tests of classical function show that the evolutionary algorithm,with simulated annealing rank selection operator,can restrain premature convergence phenomenon effectively during the evolutionary process while increasing the search efficiency greatly.关键词：race exponent;simulated annealing rank selection operator;ethnic group evolution algorithm2|1120|6更新时间：2025-07-16
- 摘要：Considering lack of comparative studies on Ping-pong handover,a comprehensive evaluation was carried out to estimate the handover performance of layer-3 of TCP protocol based on end-to-end for various Mobile IPv6 extensions.Simultaneously,the latency,throughput and packets loss rate of ping-pong handover in classical mobile IPv6 protocols such as MIPv6,HMIPv6,FMIPv6 and FHMIPv6 are simulated.Based on which,a novel scheme,optimized FHMIPv6 is proposed.A new Hop-by-Hop option header named TM (Tunnel Message) header,PCoA Table and Tunnel Table are defined in this scheme to implement MN’s fast and seamless handover.Compared with FHMIPv6,the new scheme can further reduce the handover latency and eliminate the possibility of packets loss as well as improve the whole throughput.关键词：Ping-pong handover;MIPv6;FMIPv6;HMIPv6;FHMIPv64|1161|5更新时间：2025-07-16
- 摘要：In this paper,the starting point problem of parameters estimation for LFM signal based on Newton’s method is investigated.The DPT algorithm is used to gain the estimated value of the coefficient of frequency modulation and the center frequency of the LFM signal,and the two estimation values are used as the starting point of Newton's method.The performance analysis show that when signal-to-noise ratio(SNR) is greater than the SNR threshold of the DPT algorithm,the two estimations are in the range of the convergence region needed by Newton's method.So it will guarantee the convergence of Newton's method.The simulation results show that when SNR is greater than SNR threshold,the RMS error of the parameter estimations can reach the CRLB.The computational complexity of the algorithm proposed in this paper is low,and the algorithm is convenient for realizing quasi-real-time LFM signal processing.关键词：LFM signal;parameter estimation;Newton's method;maximum likelihood;Cramer-Rao lower bound(CRLB)2|1376|9更新时间：2025-07-16
- 摘要：The soft X-ray picosecond framing camera based on the gated microchannel plate (MCP-XPFC) is a type of ultra-fast diagnostic tool that applied widely for ICF and plasma researches.By using the uniform design,a temporal-resolved regression equation of MCP-XPFC was presented.The analytic emphasis is the interaction of the gating electric pulse's width and amplitude on the temporal resolution.The temporal resolution of camera was computed by the gating theoretic model and the regression equation respectively,and measured by femtosecond laser system on the base of two groups parameters,the gating electric pulses applied on the micro-strip lines of the MCP-XPFC with V1(t) (250ps,1200V) and V2(t) (170ps,1400V).At last,the theoretic and experimental error was analyzed.The optimized voltage range are 800~1200V for electric pulse of 250 ps and 1100~1200V for electric pulse of 170ps.关键词：microchannel plate (MCP);uniform design;framing camera;temporal resolution;gating electric pulse3|1445|0更新时间：2025-07-16
- 摘要：In Mobile Wireless Sensor Networks (MWSN) with a sparse node population,an end-to-end path may be broken frequently or may not exist at any time due to nodes’ mobility,which makes it impossible to apply the existing shortest-path routing protocols based on static topology for MWSN.An RSSI-based opportunistic routing protocol for MWSN,called OR-RSSI,is proposed in this paper.In OR-RSSI,Opportunistic Probability(OP)based on the RSSI of the Sink’s Beacon packets and Mobility Vector (MV) is established and the best node with the highest OP is chosen to store and relay packets at each hop after packets are broadcasted.Simulation results show that OR-RSSI performs better on successful delivery ratio,goodput and energy overhead as compared with traditional TinyAODV.关键词：mobile wireless sensor networks;opportunistic routing;RSSI;mobility vector2|1499|9更新时间：2025-07-16
- 摘要：SAT-based bounded model checking (BMC) is introduced as a complementary technique to OBDD-based symbolic model checking,and is a verification method for parallel and reactive systems.However,until now the properties verified by bounded model checking are very limited.Temporal logic PSL is a property specification language (IEEE-1850) describing parallel systems and is divided into two parts,i.e.the linear time logic FL(Foundation Language)and the branch time logic OBE(Optional Branching Extension).The specification checked by BMC is extended to PSL and its algorithm is also proposed.Firstly,define the bounded semantics of PSL,and then reduce the bounded semantics into SAT by translating PSL specification formula and the state transition relation of the system M into the propositional formulas,respectively.Finally,verify the satisfiability of the conjunction of the two propositional formulas.The algorithm results in the translation of the existential model checking of the temporal logic PSL into the satisfiability problem of propositional formula.An example of a queue controlling circuit is used to interpret detailedly the executing procedure of the algorithm.2|906|1更新时间：2025-07-16
- 摘要：We propose an algorithm addressing the problem of template drift in object tracking.Template drift is a common phenomenon in which the target gradually shifts away from the template and the template is gradually occupied by background objects due to template update.In order to solve this problem,this paper derives expressions that accurately evaluate the influence of template drift on the template-updating filter,so that the filter achieves a quasi-optimal balance between reducing template drift and keeping track of target appearance variations in a spatiotemporally adaptive manner.Experimental results based on a wide range of real-world video sequences containing diverse degrees of target appearance variations confirm the effectiveness of our algorithm.关键词：object tracking;template drift;template matching;adaptive Kalman filtering3|1418|11更新时间：2025-07-16
- 摘要：By inspiration of the granular evolutionary algorithm,a Granular Agent Evolutionary algorithm for Classification (GAEC) is proposed.The method uses the granular agent to denote the set of examples that have similar attributions and the knowledge base guides the evolutionary of granular agent.Also some granular evolutionary operators are designed for classification problem.Assimilation operator,exchange operator,and differentiation operator reflect the competitive,cooperative and self-learning ability of agent respectively.Finally,some classification rules are extracted from granular agents by some strategies to forecast the sort of new data.Empirical studies show that the algorithm has a good classification prediction,and only need a small price for the training time.In most UCI datasets,the performance of GAEC is better than G-NET,OCEC and C4.5,which have good performance.关键词：classification;granular agent;assimilation;exchange;differentiation3|968|0更新时间：2025-07-16
- 摘要：Aperture arrays are often designed to provide airflow through shielding walls so that the interior temperature of electronics equipment can be controlled bellow a required level.The electromagnetic energy leakage through the aperture arrays is inevitable,thus the near-field shielding effectiveness must be analyzed when the distance between the radiator and the shielding wall or the distance between two adjacent shielding walls satisfies the near-field condition.In this paper,the FEM for apertures is firstly introduced based on electromagnetic field theory,and the calculation approach of shielding effectiveness by numerical method and the formulation based on the plane wave theory are compared.Then,the effects of some related parameters on near-field shielding effectiveness are analyzed thoroughly.As a result,an approach to improve near-field shielding effectiveness is presented.By the FEM,the shielding effectiveness of aperture arrays with different shapes is analyzed.As the theoretical analysis and simulation results showing,the shielding effectiveness of aperture arrays is greatly overestimated by the classical plane wave theory and the numerical method is more effective in the calculation of near field.The results from numerical simulation shows that the near-field shielding effectiveness can be elevated by reducing the ratio of the size of an aperture to the wave-length of radiator or increasing the number of apertures while the area of apertures keeps unchanged,and three kinds of aperture arrays commonly used in engineering have the similar near-field shielding effectiveness.关键词：aperture array;near-field;FEM;shielding effectiveness2|1301|5更新时间：2025-07-16
- 摘要：As the high-power amplifier nonlinear effect,the limited bandwidth of the navigation signal distortion increase,which would affect navigation signals in the power spectrum,and pseudo-code tracking accuracy.To address this issue,this paper established the generic model for analyzing navigation signals non-linear distortion,used out-of-band power loss,the correlation loss and the offset of zero-crossing of S-Curve to assess the impact on navigation system performance,and analyzed how the bandwidth restrictions and nonlinear effects impacted on Rectangular pulse shaped,SRC(Square Root cosine) pulse shaped,BPSK modulation and BOC modulation.关键词：non-linear amplifier;spectrum regrowth;PRN tracking accuracy2|1427|6更新时间：2025-07-16
- 摘要：A practical method of measuring microwave resonator unloaded Q-factor is presented,which could eliminate phase shift of feed line when Q-factor is estimated by critical-points method.The presence of the phase shift would rotate the resonator’s input-impedance locus in Smith Chart,thereby affecting measurement result.To de-embed the phase shift,an objective function was introduced to find the proper rotation angle caused by feed line instead of calibration using extra measurement.The method was demonstrated by simulation data and measurement data.关键词：critical-points method;microwave resonator;unloaded Q-factor;phase shift2|952|1更新时间：2025-07-16
- 摘要：To solve the effect of the velocity on the range profile,a compound velocity measurement method for the stepped-frequency Chirp signal is presented.With the derivation of narrowband tracking ranges,velocity compensation and envelope migration are finished.Then with the correlation processing of the positive-positive stepped-frequency signals,and followed with the tracking loop,the velocity is coarse estimated and tracked.After that the acceleration is compensated with the tracking velocity derivation.At last with the correlation processing of positive-negative stepped frequency signals,the precise velocity is obtained.Simulation results prove the feasibility of the proposed method.关键词：stepped-frequency chirp signal;velocity measurement;high speed moving target;positive negative correlation2|1136|10更新时间：2025-07-16
- 摘要：A five-dimensional hyperchaotic system is constructed by introducing two controllers into the Lorenz system.Existence of hyperchaotic behavior is proved by Lyapunov exponents.Equlibrias and dissipation of hyperchaotic system are analyzed.Based on the stability criterion of linear system,projective synchronization of hyperchaotic system is achieved through linear separation methods.关键词：hyperchaotic system;Lyapunov exponents;linear separation;projective synchronization2|1241|2更新时间：2025-07-16
- 摘要：In this paper,a new method for equalizing the channel frequency response errors is presented based on the echo data in airborne radar.The method selects a pair of highly-correlated echoes from the reference and under-equalization channels,which are taken as the expected signal and the input signal of the equalizer,respectively.The wiener filter theory can then be used to estimate the coefficients of the equalizer.Theory analysis shows that the estimated equalizer approaches the practical mismatch errors in the situation that the clutter-to-noise ratio (CNR) is high enough.This method can equalize the mismatch of the transmission line and the receiver simultaneously,without refitting the radar equipments in use.Experimental results of a pair of measured data are given to demonstrate the validity of the proposed method.关键词：channel equalization;airborne radar;measured data;ground clutter model2|989|3更新时间：2025-07-16
- 摘要：In order to avoid the overflow and parameter sensitivity in standard electromagnetism-like mechanism algorithm,a formula for particle charge is presented.Based on the attraction-repulsion principle in the electronic space,the particle is moved towards favorable region along the direction of total force exerted on it.The neighbor search is adopted to improve the particles in the population in order to enhance the local exploration ability.Based on these,a modified electromagnetism-like mechanism algorithm is proposed and its convergence to the vicinity of global optimum with probability one is proved.Simulation results on 28 benchmark problems demonstrate that the novel algorithm has the fast convergence and good performance in comparison with other existing algorithms.关键词：attraction-repulsion;unconstrained optimization;electromagnetism-like mechanism(EM)algorithm2|1146|19更新时间：2025-07-16
- 摘要：The computational burden of cross-ambiguity function is very large for measuring the time delay difference and the Doppler frequency shift of passive radar,which is difficult to meet the real-time requirements by the general algorithms. This paper proposes two fast algorithms of cross-ambiguity function for passive radar:the multi-stage decimation FFT algorithm and the pre-weighting multi-stage decimation FFT algorithm. The multi-stage decimation FFT algorithm decreases the length of the anti-aliasing filters and save the computational amount and the storage. The pre-weighting multi-stage decimation FFT algorithm avoids the cycle of the first-stage filter multiplication in different time delays and further increases the computational efficiency at the expense of the large storage. Experimental results show that the proposed algorithms can effectively increases the computational efficiency.关键词：passive radar;cross-ambiguity function;multi-stage decimation;pre-weighting2|2106|20更新时间：2025-07-16
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