最新刊期
卷 45 ， 期 1 ， 2017
- 摘要：Image-based localization has wide applications including auto navigation,path planning,virtual reality,etc.For the end user,a single image is required.In this paper,we present a ray-based image localization system including ray-based 3D reconstruction and pose graph optimization-based localization.By using the inherit geometry properties of ray-based camera model,the proposed reconstruction algorithm can deal with various wide FOV camera models (panorama and fisheye) to reduce the reconstruction cost and achieve a better reconstruction result.The proposed pose graph optimization localization framework can combine 2D-3D matches information and relative pose information for a better localization accuracy.Experiment result shows the effectiveness of the proposed system.关键词：image-based localization;ray based camera model;3D reconstruction;pose graph optimization;panorama339|1311|0更新时间：2025-07-16
- 摘要：The existing studies focus mainly on the zero forcing of self-interference without the suppression for the RF transmitter noise in the full-duplex base station with multiple transmit and receive antennas.Considering the suppression for the RF transmitter noise,this paper proposes a joint transmit and receive beamforming algorithm.First,we derive the analytical expression of the receiver beamforming vector based on the maximum signal-to-interference-noise ratio(SINR) criterion.The algorithm for designing the transmit beamforming vector is then given by minimizing self-interference.The simulation results show that when the signal-to-noise ratio(SNR) are 30dB and 60dB respectively,the values of the self-interference cancellation are 65.5dB and 89.8dB for the base station with three transmit and three receive antennas.Meanwhile,the corresponding improvement are 25.5dB and 19.8dB respectively compared to the SVD zero forcing scheme.关键词：wireless communication;self-interference cancellation;multi-antenna;co-time co-frequency full duplex(CCFD);beamforming;signal-to-interference-noise ratio(SINR);transmitter noise321|669|12更新时间：2025-07-16
- 摘要：There exist two criterions for the existing LDPC decoding algorithms at node-processing,majority-logic processing and fully processing.The algorithms can't make flexible tradeoffs between performance and complexity,since their threshold parameters are usually set to be unvaried.This paper first presents a generalized threshold-function,which can apply to most of the existing binary LDPC decoding algorithms to control the participating-nodes in the iterations by adjusting the threshold parameters.Then a new non-uniform quantization decoding algorithm combined with syndrome and constellation mapping information is presented,which can further reduce the complexity and memory load.Simulation results show that the presented algorithm can obtain excellent decoding performances with very low quantization level over the Rayleigh fading channel.Furthermore,it is shown that only 30% variable nodes are involved in the iterations when combined with the presented threshold-function,which can remarkably reduce the complexity.关键词：LDPC code;threshold-function;iterative decoding;decoding complexity;non-uniform quantization191|493|1更新时间：2025-07-16
- 摘要：A signal processing method based on empirical mode decomposition (EMD) is proposed,aiming at the serious interference problems that exist in the vibration displacement tests for the vehicle weapon.A new judgement criterion of determining the trend is presented for extracting the trend effectively.According to the symmetrical characteristics of the vibration signal relative to the time axis,the method determines whether the IMF component belongs to the trends by comparing the mean value between each order IMF component and the original signal.Effectiveness of the method is verified by the simulation vibration signal.The measured signals are processed by EMD,and the vibration displacement signal eventually is reconstructed.By comparing with wavelet transform method and a qualitative EMD trend determinant method,the results show that the trend extraction method based on EMD is effective and helpful to evaluate the performance of the weapon objectively.关键词：signal processing;vibration displacement;trend;EMD;wavelet transform252|1218|17更新时间：2025-07-16
- 摘要：Joint diagonalization (JD) is an efficient tool for blind source separation (BSS) problems.However,most existing JD algorithms could only be used for real-valued space BSS problems and set many constraints on target matrices.In order to solve the general complex-valued space BSS problems,a structural traits based joint diagonalization (STBJD) algorithm is proposed.The algorithm discards pre-whitening procedure,relaxes the positive-definiteness assumption on target matrices and can be used in complex-valued space,thus has more general utilizations.Matrix transformation was adapted to transform the complex-valued space target matrices being jointly diagonalized to real-valued space ones with distinct structural traits.Furthermore,the Least Square cost function for JD was established and solved by alternate least squares (ALS) iterative algorithm.The structural traits of concerned variables were fully exploited and technical utilized in the optimizing process.Finally,the mixing matrix could be estimated and the sources could be retrieved.Numerical simulations illustrated the better convergence performance of STBJD than that of the state-of-the-art algorithms such as FAJD and CVFFDIAG.Thus it could be applied to solve the BSS problems efficiently.关键词：blind source separation (BSS);joint diagonalization (JD);STBJD algorithm;alternate least squares iterative algorithm239|492|2更新时间：2025-07-16
- 摘要：Compressed data separation is one of the hot research theories of signal sampling.Under the condition that the redundant dictionary and perturbation matrix satisfy mutual coherence and restricted isometry property,respectively,the reconstruction condition and error estimation of compressed data separation via nonconvex lq(0<q≤1) minimization are established.Under different redundant dictionaries and perturbation,our results show that nonconvex lq(0<q≤1) minimization can still robustly reconstruct the original signal.In view of two different redundant dictionaries-the discrete cosine transform and wavelet transform,we conduct a series of simulation experiments to testify the strong robustness and stability of nonconvex lq(0<q≤1) minimization method with various perturbation and additive noise.The obtained results provide a reference for further development and application of compressed sensing and data separation.关键词：compressed data separation;lq minimization;mutual coherence;restricted isometry property(RIP);tight frames;perturbation159|371|1更新时间：2025-07-16
- 摘要：Multi-view active learning is a technique which can realize more significant reduction on version space than traditional active learning and has been used in large-scale data analysis.This paper proposes two improvements in both hypothesis generation and sampling strategy.We integrate boosting-like idea into the active learning framework which uses the weighted voting of all hypothetic outputs from the past queries.Furthermore,a novel adaptive hierarchical competition sampling is presented.In this sampling strategy,if the number of the contention samples is large,an unsupervised spectral clustering is activated to obtain the coarse distribution of these contention samples in the feature space and then both the classification uncertainty and redundancy measures are considered in each cluster to query the unlabeled samples in batch mode by solving quadratic programming.We apply multi-view active learning in image classification in order to prove the effectiveness of the improvements and different image features are used as views to generate the corresponding hypothesis.The experiments demonstrate that our two proposals can both efficiently improve the performance of the multi-view active learning and the random combination of these views can also obtain faster convergence and better classification accuracy than state-of-the-art single-view active learning algorithms.关键词：multi-view active learning;weighted hypothesis boosting;hierarchical competition sampling;image classification169|372|3更新时间：2025-07-16
- 摘要：The problem of phase retrieval,namely,recovery of a signal only from the magnitude of its Fourier transform,or of any other linear transform.Due to the loss of phase information,this problem is ill-posed.Therefore,the prior knowledge is required to enable its accurate reconstruction.In this work,based on the framework of nonlinear compressive sensing,a novel phase retrieval algorithm which exploits the sparsity of the natural images under the image gradient operator is proposed.The algorithm incorporates the total variation regularization into the phase retrieval problem,which based on support constraints and amplitude constraints.Moreover,alternating direction method of multipliers (ADMM) is utilized for solving the corresponding non-convex optimization problem.Experimental results indicate that the performance of the proposed algorithm outperforms the classical algorithms,such as HIO,RAAR,moreover,it is robust to noise.关键词：phase retrieval;nonlinear compressive sensing;sparsity;total variation;gradient operator202|1078|4更新时间：2025-07-16
- 摘要：To solve the problem of quantization noise in OFDM systems,a study on a novel quantization noise shaper for multi-carrier signal is presented. The paper first compares the applicability of two kinds of sigma-delta modulators with the single zero and multiple zeros. Then it gives the complete scheme,theory and simulation analysis of the multi-zero sigma delta modulator for OFDM systems. Studies show that the multi-zero sigma delta modulator without oversampling can effectively reduce the quantization noise in OFDM systems,and performs better in noise shaping. Under the conditions of 3bit quantization and 6dB SNR,the bit error rate of the system deceases by 3 order of magnitude. But limited by the non-cyclic quantization noise structure,the proposed modulator cannot achieve the ideal state of eliminating the quantization noise completely.218|352|4更新时间：2025-07-16
- 摘要：The optimization of secrecy rate is studied in the wireless relay-eavesdropper channel in which the nodes harvest energy.An enhanced physical layer security communication scheme is proposed based on artificial noise-aided cooperative jamming and energy cooperation.All nodes follow the save-then-transmit protocol.The nodes harvest energy first,which is then used to transmit the data.The relay is operated as an amplify-and-forward relay,and the destination sends intended jamming noise to protect information.Since the relay requires more energy,surplus energy is transferred from the destination to the relay to increase the available power of the relay.A two-step optimization algorithm to maximize the secrecy rate is derived through the optimization of the energy-saving time ratio and the jamming power allocation scaling factor.The simulation results prove that the proposed energy cooperation scheme can effectively improve secrecy rate.关键词：secrecy rate;energy harvesting;energy cooperation;cooperative jamming;physical layer security203|413|1更新时间：2025-07-16
- 摘要：For the problem of high slant-range sampling ratio and huge echo data volume in the high-resolution three-dimensional imaging system of forward-looking array SAR,the joint two-dimensional sparse sampling method in the domain of slant-range frequency and along-track time and its sparse reconstruction method for the three-dimensional imaging of the scene is presented,which is based on the sparse property of the scatterers in the three-dimensional space.From the perspective of forward-looking array SAR to observe the three-dimensional ground,the scatterers in the ground are sparse in the joint space of the slant-range direction and the along-track direction.To avoid the effect of the sparse sampling in the slant-range direction on the three-dimensional imaging,the solution of sub-pulse technique and the sparse sampling in the slant-range frequency is presented to accomplish the sparse sampling in the slant-range direction.Also,the sparse reconstruction method,which is combined with the continuity of the scatterers,is proposed to increase the robustness in the situation of low signal-to-noise ratio.Compared to the traditional imaging method with three-dimensional matched filtering,the method in this paper reduces the slant-range sampling ratio and the echo data volume,and the three-dimensional image can be directly reconstructed using the recovered scatterers.关键词：three-dimensional imaging;forward-looking array SAR;sparse sampling;compressive sensing imaging289|1453|4更新时间：2025-07-16
- 摘要：For helicopter external high precision magnetic survey pod detection platform,platform background magnetic interference mechanism is analyzed,and concluded that platform background magnetic disturbance consists of the aircraft carrier magnetic disturbance,fluctuating magnetic interference caused by pod swing and the magnetic disturbance caused by fluctuating track of platform.Magnetic survey pod trajectory calculation model and platform background magnetic interference small signal model are established.And combining with the characteristics of platform motion,small signal model solving method is given.Through simulation and calculation,the magnetic interference small signal model is verified,and the analysis results show that using the small signal model to solve and compensate the magnetic disturbance is completely possible,the adaptability is very good and magnetic disturbance compensation rate can reach more than 90%.关键词：magnetic anomaly detection;small signal model;magnetic survey pod;magnetic disturbance compensation212|999|3更新时间：2025-07-16
- 摘要：A jamming technique aiming at phase-coded stepped-frequency radar is proposed.The modulation characteristic of phase-coded stepped-frequency signal and multi-carrier phase-coded signal is analyzed.On the basis of the above,a new jamming technique of multi-carrier phase-coded repeater is presented.The new jamming effectiveness is analyzed theoretically.This method can make phase-coded stepped-frequency radar form several precede and lag lifelike false targets.The relativity of m series in equal length is studied.The opt principle of jamming signal sub-carrier and phase-coded series are presented.The conclusion is proved by simulation experiment.The studied result indicates that this jamming technique is superior to jamming technique of intermittent-sampling predictive repeater.关键词：signal processing;phase-coded stepped-frequency;multi-carrier modulation;intermittent sampling;repeater jamming236|419|5更新时间：2025-07-16
- 摘要：When the random pulse repetition interval (RPRI) compressed sensing radar suffers from the jamming of active velocity false target,the sparsity of target echoes will be destroyed and the RPRI compressed sensing radar's superiority on target detection and velocity measurement will be limited.In practice,due to the random modulation,the jammers can hardly update precise parameters such as the random PRI in time,which will induce the echo signals of true and false target to be sparse in different dictionaries.By utilizing this factor,a velocity false target identification algorithm is proposed within the frame of compressed sensing.The echo signals of true and false target can be sparsely presented and separated by building a joint dictionary.Also,to present application limitation of the algorithm,the autocorrelation of the joint dictionary under different RPRI signal's random mode is analyzed as well as its influence on the separation results.Computer simulation verifies the effectiveness and superiority of the algorithm.关键词：random pulse repetition interval signal;compressed sensing;false target identification;moving target detection163|518|3更新时间：2025-07-16
- 摘要：A new method based on multi-task learning for the design of sparse conformal array is presented.Considering the different orientations of antennas and variable curvature radius of the platform,array manifold model for 3D conformal array is established.Combined with the framework of multi-task learning (MTL),the pattern of uniform conformal array antenna scatting on a cone aperture is studied.In accordance with the identified sparse vector supporting area,the under-determined steering vector matrix equation is transformed into the over-determined conversion feature matrix equation.The synthesis performance comparisons with matrix pencil method and genetic algorithm are performed to demonstrate the superiority of the proposed algorithm over traditional algorithm in the literature.And a sparse conformal array antennas design with favorable pattern matching is obtained by MTL method.关键词：conformal array;sparse array antennas;MTL (multi-task learning);pattern synthesis290|678|7更新时间：2025-07-16
- 摘要：A novel microblog recommendation method combining the tag correlation with the user social relation is proposed via analyzing microblog features and the deficiencies of existing microblog recommendation algorithm.Specifically,we establish a tag retrieval strategy to add tags for unlabeled users and users with few tags,and then build the user-tag matrix and obtain user-tag weights.In order to solve the problem of sparsity of the matrix,we investigate the correlation between the tags to update the user-tag matrix.Considering the significance of user social relation for microblog recommendation,a user-user social relation similarity matrix is constructed and a mechanism is designed to iteratively obtain user interest.Experimental results show that the algorithm is effective in microblog recommendation.关键词：microblog recommendation;tag retrieval;user-tag matrix;user-tag weight;tag correlation;user-user social relation similarity matrix464|1003|7更新时间：2025-07-16
- 摘要：Constructing underlying logic trees can effectively reduce the large communication overhead for centralized top-k query.In this paper,an energy-balanced optimal support-tree is proposed to solve the problem of earlier death for nodes near sink in sensor networks without fixed sink.This method aggregates node energy,degree and communication overhead,and nodes with low energy cost are chosen to be dominating nodes for data processing based on connected dominating set.In each query,nodes take turns to be root by location-based ID,which effectively balances the energy cost.The simulation experiment shows that top-k query based on support-tree outperforms the existing trees by similar query time,but lower average energy cost per round and balanced consumption among all sensor nodes after continuous top-k queries,which effectively prolong the network lifetime.关键词：Wireless sensor networks;top-k query;connected dominating set;energy-balanced;optimal support-tree275|508|2更新时间：2025-07-16
- 摘要：The diversified and high-speed development of network traffic presents a great challenge for traffic identification.As an effective method for data dimensionality reduction,the research of feature extraction is of great significance.A secondary traffic feature extraction model is described as the foundation of the secondary feature extraction algorithm of network traffic.The algorithm divides traffic data into several subsets and gathers the features extracted from different subsets.The index of influence is proposed as the reference of feature ranking and extraction.The experiment results show that the secondary traffic feature extraction model has better performance,and the algorithm can identify traffic more accurately with fewer features.关键词：secondary feature extraction;divide-conquer;ranking;influence;traffic identification216|904|2更新时间：2025-07-16
- 摘要：To calibrate the camera,a linear camera self-calibration method based on non-rigid trajectory basis is presented in this paper.Based on the fact that the trajectories of non-rigid span a low subspace which can be spanned by an orthogonality wavelet basis,the camera self-calibration can be linearly realized.Because the wavelet basis can be predefined,the solved parameters are deduced and the camera self-calibration becomes a linear optimal problem,which can improve the robustness of the algorithm.The experiments of both simulation and real data show that the presented method can efficiently realize the camera self-calibration.关键词：camera self-calibration;non-rigid;trajectory basis69|325|2更新时间：2025-07-16
- 摘要：Existing vision-based pedestrian detection methods encounter many flaws,such as high false and miss detection rates,low detection accuracy on partial occluded and small scale objects,etc.In this paper,we propose a pedestrian detection method combining textual and visual information together.First,we use a vision-based method to initially localize the candidate visual objects.Second,we analyze the text information to get the text mentions corresponding to the visual objects.Finally,we propose a Markov random field-based model to infer the coreference relations between the candidate visual objects and textual mentions,so that the visual and textual information can be fused efficiently.The experimental results on the Caltech pedestrian detection benchmark enriched with textual description information have shown that the proposed method can not only improve the pedestrian detection accuracy by combining textual information with visual information,but also outperform the baseline anaphora resolution model by combining visual information with textual information.关键词：pedestrian detection;Markov random field;text and image information combination;coreference relation;anaphora resolution115|1061|5更新时间：2025-07-16
- 摘要：To address the misjudgment caused by all boundaries of an image being equally and artificially selected as background in most of state-of-the-art models using background prior,this paper proposes an algorithm called weighted contrast optimization based on discriminative background.Firstly,a metric is constructed to roughly but objectively estimate a saliency map,which is used to choose a better background map.Based on this metric,a reliable background detection model is constructed through geodesic distance transformation after discriminating each boundary via Hausdorff distance.Then,the only background weighted contrast is improved into fore-background weighted contrast.Last,the final saliency map is obtained through weighted optimization framework.Extensive experiments on five public datasets demonstrate that the proposed algorithm outperforms state-of-the-art methods.关键词：saliency detection;background map;discriminative boundary;weighted contrast82|227|1更新时间：2025-07-16
- 摘要：The visual features of the state-of-the-art image retrieval methods lack of learning ability,which lead to low expression ability.And the efficiency of traditional index methods is fairly low for large image database.In view of this,an image retrieval method based on convolutional neural network and kernel-based supervised Hashing is proposed.Firstly,a large convolutional neural network is employed to learn the intrinsic implications of training images so as to improve the distinguish ability and expression ability of visual feature.Secondly,kernel-based supervised Hashing is applied to learn from the high-dimensional visual feature and map into low-dimensional hamming space and achieve compact Hash codes.Finally,image retrieval is accomplished in low-dimensional hamming space.Experimental results of ImageNet-1000 and Caltech-256 datasets indicate that the expression ability of visual feature is effectively improved and the image retrieval performance is substantially boosted compared with the state-of-the-art methods.关键词：deep learning;image retrieval;convolutional neural network;approximate nearest neighbor;kernel-based supervised Hashing122|1464|16更新时间：2025-07-16
- 摘要：In order to strengthen the robustness of the extracted features for individual differences and use the distribution characteristics of the features more effectively,this paper presents a hierarchical classification method of expression based on geometric and texture features.Firstly,a geometric feature extract method is constructed based on the similarity of neutral expression,which automatically matches with the similar neutral expression images of sample images and extract geometric features based on feature points scale factor.Then,texture features are extracted by using sufficient vector triangle pattern.Finally,the facial expression hierarchical classification framework is achieved by using the above features to judge expression categories in the three layers respectively.Experiment results in JAFFE database and CK database show that the proposed method improves the recognition rate compared with the methods based on the typically geometric and texture features.关键词：expression recognition;geometric and texture features;similarity of neutral expression;hierarchical classification150|537|8更新时间：2025-07-16
- 摘要：With its wide-angle imaging and information richness,the fish-eye camera has a brilliant prospect in application.This paper presents a moving object detection method for on-board monocular fish-eye cameras.Firstly,a sub-block motion compensation model is proposed to compensate image background motion,which solves the ineffective strong parallax scene compensation problem.Secondly,when it comes to solve the parameters of sub-block motion compensation model,ego-vehicle motion parameters are introduced to simplify the number of model parameters,and the direct method is used to avoid the problem that the traditional feature-point-based matching method is susceptible to mismatching feature points.Then for the image distortion problem,this paper proposes a three-plane rectification method to obtain sub-block motion compensation images.Finally,the moving object detection is realized using the difference between sub-block motion compensation images and captured images.Experimental results show the effectiveness of the proposed method.关键词：moving object detection;sub-block motion compensation;monocular vision;fish-eye camera246|484|8更新时间：2025-07-16
- 摘要：Poisson noise has strong relationship with the gray-values of image,meanwhile the gray-values of image can be represented by level line.In the framework of the Bayesian-MAP,a Poisson denoising variational regularization model is proposed.The Euler's elastica energy is used as a prior regularization term combined with negative-log Poisson likelihood.By using the alternating direction method of multipliers (ADMM),we transform the original high-order optimization problem into several low-order sub-problems.Then the lagged diffusivity fixed point iteration is applied to solve the high-order nonlinear term.For images with strong or weak Poisson noise,experiments show the validity and efficiency of the proposed method both in preserving geometric structure and suppressing noise.关键词：Poisson denoising;Euler's elastica;level line;variational regularization239|598|4更新时间：2025-07-16
- 摘要：Dependable service components selection is the key to implement dependability assurance in distributed virtualized environment.The service components selection can be modeled as Multi-Constrained Optimal Path(MCOP) problem,and service components will be selected by searching trust path.However,existing trust path search algorithms have disadvantages of high complexity and low performance.And the researches about modeling dependable service components selection lack the consideration of trust relationships and evidence spread among service components during service construction and composition.Therefore,we proposed the concept of QoD,the Quality of Dependability,introducing the attributes(e.g.componentintimacy) to describe and restrict the model of service components selection in distributed virtualized environment.We also designed a heuristic optimal trust service path search algorithm HA_OTPS,and chose service components on the optimal trust service path to satisfy users' demand for service dependability.The experimental results showed that HA_OTPS has shorter execution time and higher utility of search results than the existing trust path search algorithms.关键词：distributed virtualized environment;dependability assurance;service composition;trust path93|380|1更新时间：2025-07-16
- 摘要：Information rate of secret sharing scheme is an important indicator to measure the communication efficiency of secret sharing,in view of the problem that the existing secret sharing schemes efficiency are not high,a verifiable secret sharing scheme with information rate for m/(m+1) was proposed based on multiple linear.In this scheme,the shared secret is m dimensional vector,the verifiability can be achieved by using the multiple linear pair property of multilinear map.And,as well,the scheme is provably secure under the multilinear Diffie-Hellman problem.The performance analysis results show that this scheme has a higher communication efficiency compared with the existing secret sharing schemes under the same level of security,which is more suitable for those data fault-tolerant communication limited application scenarios.关键词：verifiable secret sharing;multilinear map;information rate;multilinear Diffie-Hellman problem136|633|8更新时间：2025-07-16
- 摘要：For the formation control problem of the car-like mobile robot with longitudinal slip,a formation control algorithm is proposed based on the compensation of slip ratio and fuzzy logic.Firstly,the real velocity of the robot is acquired by sensors.And decrease the noise through filtering.Then the real velocity is compared with the input velocity signal to get the estimation of slip ratio,which represents the degree of slip.According to the leader-follower method,a formation control strategy with compensation of slip ratio is designed,and fuzzy logic is adapted to design controller parameters.Finally,simulations are designed in the Microsoft Robotics Developer Studio 4.The simulation results show the effectiveness of the presented method in many situations when the leading or following robot slips.关键词：car-like mobile robot;longitudinal slip;fuzzy control;formation control149|424|6更新时间：2025-07-16
- 摘要：Progressive Bayesian methods formulate the Bayesian update as continuously pseudo-time probability density evolution to perform posterior state estimation.In this paper we derive a novel Gaussian nonlinear filter based on progressive Bayesian framework.A progressive Bayesian solution is firstly derived under linear Gaussian condition.It is proved that the moment evolution of the dynamic system determined by linear Gaussian solution possess the consistency with Kalman-Bucy filter for constant state estimation.For nonlinear system,by using first order Taylor expansion,an approximate solution is derived and the resultant progressive extended Kalman filter is presented.Simulation results demonstrate the superior performance of progressive extended Kalman filter over extended Kalman filter,moreover the performance degrading of nonlinear filtering caused by narrow shape likelihood is avoided.关键词：nonlinear filtering;progressive Bayesian;Kalman-Bucy filter;extended Kalman filter89|763|3更新时间：2025-07-16
- 摘要：Dynamic economic dispatch (DED) is a multi-stage decision problem with space and time coupling.In order to get the global optimal solution,a DED problem generally has been transformed into a high-dimensional constrained numerical optimization problem to solve.In this study,a novel global optimization algorithm,cluster evolutionary algorithm (CEA),is proposed to solve DED problem.In CEA,a virtual cluster organization is constructed among individuals so as to dynamically adjust the searching process of simulated evolutionary system while improving the optimization efficiency of population.In simulations,CEA is applied to 2 DED testing systems for verifying its feasibility.Meanwhile,a comparative study is carried out with other existing methods.Results clarify the significance of the proposed algorithm and verify its performance.Considering the quality of the solution obtained,CEA seems to be a promising alternative approach for solving the DED problem.关键词：evolutionary algorithm;cluster searching mechanism;dynamic economic dispatch64|322|0更新时间：2025-07-16
- 摘要：Monitoring the sleep quality accurately can play an effective supporting role in helping people improve the quality of sleep.In the present study,a novel feature extraction algorithm is proposed based on the natural visibility graph and horizontal visibility graph methods.The slope of visibility degree distribution,the mean of visibility distance,the mean of averaged visibility distance and the mean of improved weighted visibility graph were extracted,and trained by the least square-support vector machines (LS-SVM) classifier.The mathematical model between electroencephalogram (EEG) and sleep state was established and verified by different samples.The results demonstrated that the classification accuracy of different states improved about 5.72% compared to the existing weighted visibility graph,the classification accuracy of shallow sleep states improved about 9.65%.关键词：EEG(Electroencephalogram);visibility graph;LS-SVM(Least square-support vector machines)106|924|0更新时间：2025-07-16
- 摘要：An efficient and accurate technique based on the impedance theory of cavity-backed slot antenna is introduced to calculate the resonant frequencies of a rectangular enclosure with a slot on its wall.Expressing electromagnetic fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure,an integral equation for equivalent magnetic current is obtained by enforcing the boundary condition across the slot.The Method of Moments is used to solve the integral equation for the input impedance.We can get resonant frequencies from the zero reactance or the minimum resistance on the frequency-impedance curves.Our method is verified successfully by experimental results and CST.The effects of the cavity size,of the slot length,and of the slot offset on the resonant frequency are discussed.关键词：cavity-backed slot antenna;resonant frequency;shielded enclosure;method of moments172|930|1更新时间：2025-07-16
- 摘要：The evolution strategy (ES) based on covariance matrix adaptation (CMA) is an excellent,gradient-free stochastic local optimization method.The learning mechanism based on CMA enables evolution strategy algorithm to have invariance to any invertible linear transformation of the search space,and to have outstanding capability for solving the ill-conditioned and/or highly non-separable problems.The learning mechanism of CMA has a solid theoretical foundation in mathematics,which may have a certain reference significance to guide the design of other evolutionary algorithms.This paper aims at analyzing the learning mechanisms of CMA-ES in detail,and providing its main mathematical foundations.Finally,the advantages and disadvantages of various CMA-ES variants are compared by a series of experiments,and the difference in performance is compared seriously between our improved variant and other CMA-ES variants.关键词：evolution strategy;covariance matrix adaptation;adaptive learning;multivariate normal distribution93|1351|2更新时间：2025-07-16
- 摘要：The equations of tortuous channel LEMP (lightning electromagnetic pulse) fields are derived by decomposing the micro dipole into the perpendicular component and the horizontal component.Then the electromagnetic fields on earth surface at different bottom discharge channel length and different upper part discharge channel tilt angle are calculated.The results show that the peak-value of LEMP mainly depends on the length of bottom discharge channel,in middle and far ranges with the increase of the bottom discharge channel length,the amplitude of corresponding electromagnetic field will be smaller.The tilt angle of upper part discharge channel has little impact on LEMP in near ranges,and the amplitude of electromagnetic field in intermediate area and far area will decrease with the increase of tilt angle.Moreover,the impact of tilt angle on electromagnetic field amplitude will be greater with the increase of the distance.关键词：lightning electromagnetic field;tortuous discharge channel;surface electromagnetic field;pulse function63|374|1更新时间：2025-07-16
- 摘要：The correctness of design and implementation of operating systems is difficult to be described with the traditional quantitative methods,because of the enormous size and complexity.This paper illustrates our method of formal design and verification of microkernel operating system.We construct the system model with the non-deterministic automaton in the assembly level,and use the Hoare triples to describe the previous and post conditions of the interface functions,as the definitions of function correctness.We take the module of memory management in the self-implemented VSOS (Verified Secure Operating System) as an example,to illustrate our formal method.Meanwhile,we formally describe the constructed memory management model and operation semantics of system behaviors in the Isabelle/HOL theorem prover,and verify the correctness of design and implementation of the memory management.The result shows that the method proposed is feasible and efficient.关键词：operating system;memory management;formal design;formal verification;theorem proving179|602|2更新时间：2025-07-16
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