最新刊期
卷 44 ， 期 6 ， 2016
- 摘要：The linear temporal logic (LTL) model checking is widely used in processor design and verification, network protocol verification and security protocol verification.Up to now, this technique can only be realized on the platform of electronic computer.In order to conduct LTL model checking under the circumstance of deoxyribo nucleic acid (DNA), we proposed a method to check the Until constructor via a sticker automaton.We encode a finite state automaton (FSA) which is a model of the formula Until, with a DNA sticker automaton.And we convert a model of a system into its paths, as the input strings of the sticker automaton.We verify whether the system satisfies the formula or not, by using the sticker automaton.In this way, the formula Until can be checked with the double strand DNA molecules.The simulation results show that the method can successfully check the basic temporal formulas.关键词：model checking;deoxyribo nucleic acid;linear temporal logic;sticker automaton372|2|4更新时间：2025-07-02
- 摘要：The regional temperature prediction is the basis of the efficient heat dissipation in multiprocessor system-on-chips (MPSoCs).Based on the thermal resistance and capacitance (Thermal RC) model, this paper proposed a predictive thermal model combined with the second derivative.It predicts the temperature accurately with low complexity, and increases the prediction time length within a certain prediction error range to reduce the number of times that the prediction module is invoked and the extra power consumption.Experimental results show that, compared to the existing model combined with the first derivative, the proposed model increases the prediction length by 1.6 times within the same acceptable prediction error range.When the prediction time length is increased to 2.5s, the prediction accuracy of the proposed model is 3.84% higher than that of the contrastive model.关键词：multiprocessor system-on-chips (MPSoCs);thermal resistance and capacitance (Thermal RC) model;predictive thermal model2|2|1更新时间：2025-07-02
- 摘要：Introducing velocity measurement into track filtering can improve filtering accuracy, but velocity ambiguity in LPRF radar still exists, and range differential or Kalman filter cannot solve this problem completely.Thus, a new velocity ambiguity filtering method based on multi-parameter delay decision is proposed.According to Bayes track probability, multi-hypothesis delay decision can be performed on those velocity parameters that are difficult to be decided currently, so the problem of radical velocity ambiguity in LPRF radar will be solved effectively.Simulation results show that this method is helpful for velocity ambiguity resolution and radical velocity measurement filtering, thus range estimation accuracy can be improved significantly and angle estimation accuracy can be improved to a certain extent.关键词：multiple parameters;delay decision;Bayes track probability;velocity ambiguity2|3|1更新时间：2025-07-02
- 摘要：Duality is one of the most important properties of morphological operators, and it has important applications in image processing.Since the existing vector morphological operators are unable to meet the duality, it is difficult to develop vector morphological theory and applications.In order to address the issue, we studied the properties of the existing vector morphological operators, and then found color spaces and vector ordering algorithms are two important factors which directly determine whether vector morphological operators are dual or not.In this paper, the symmetric color space and the symmetric vector distance are chosen and used to define the novel vector morphological operators with duality.Moreover, the novel vector morphological filters, gradient operators are also proposed and applied to color image corrupted by noise.Experimental results show that the proposed vector morphological operators can provide better results than the existing approaches for color image filtering and edge detection.2|2|1更新时间：2025-07-02
- 摘要：Aiming at rejecting nonstationary clutter originating from slow moving vessels and surrounding tissues, a singular-spectral-weighting-based clutter suppression method for color ultrasound Doppler imaging is presented in this paper.First, a Hankel data matrix is created from each slow-time ensemble.Then, the singular value decomposition is performed to obtain the orthogonal basis functions for regression filtering.The coefficients of the filter are adaptively computed by a modified sigmoid function from the power normalized singular spectral, which allows for means to detect regions of clutter artifacts with high specificity.To analyze the efficacy of the proposed adaptive filter, in-vitro experiments were carried out.For the experiments, raw CFI data were acquired by a commercial ultrasound system (Sonix RP, Ultrasonix Inc.).Then, blood flow parameters are estimated from an estimate of the lag-one auto correlator of the filtered signal.The reconstructed flow and power images verifies that the proposed method outperforms other tested methods in rejecting high intense nonstationary clutter, which leads to improved distinguishing between blood and tissue regions.关键词：ultrasound color Doppler imaging;nonstationary clutter;hankel singular value decomposition;spectral analysis223|4|4更新时间：2025-07-02
- 摘要：With the improvement of the nanometer technology, the influences among temperature, leakage power and heat conductance become increasingly significant and it should be taken into account in 3D chip comprehensive thermal analysis to solve the accurate temperature based on the iterative solution.The comprehensive thermal analysis method uses the nodal power density vector and the heat conductance matrix to solve the nodal temperature vector, and then, refreshes power density and heat conductance with the obtained nodal temperature.In order to improve the efficiency of 3D chip comprehensive thermal analysis, this work uses the heat conductance matrix as the precondition under a setting temperature.Then it proposes an efficient algorithm TPG-FTCG (CG with the Fast Transform-based Preconditioner) which has double-loop and lower inner-loop iterations.According to TPG-FTCG's fast inner-loop convergence rate, this work removes TPG-FTCG's inner-loop part then proposes a more efficient TPG solving algorithm TPG-Sli (Single-loop iterative), which only has single-loop iterative and fewer iterations.Based on the GPU parallel computing, this work compiles and refines TPG-Sli's GPU-parallel-computing algorithm.Experimental results demonstrate that:On the premise of precision losing, the TPG-Sli's GPU algorithm can achieve about 120X speedup compared with the TPG-ICCG algorithm, which uses the classical and efficient ICCG to deal with the 3D chip comprehensive thermal analysis.关键词：algorithm;thermal analysis;fast Fourier transform;GPU parallel computing150|2|0更新时间：2025-07-02
- 摘要：Spatial and temporal relations between different facial muscles are very important in the facial expression recognition process.However, these implicit relations have not been widely used due to the limitation of the current models.In order to make full use of spatial and temporal information, we model the facial expression as a complex activity consisting of different facial events.Furthermore, we introduce a special Bayesian network to capture the temporal relations among facial events and develop the corresponding algorithm for facial expression modeling and recognition.We only use the features based on tracking results and this method does not require the peak frames, which can improve the speed of training and recognition.Experimental results on the benchmark databases CK+ and MMI show that the proposed method is feasible in facial expression recognition and considerably improves the recognition accuracy.关键词：facial expression recognition;sequential facial events;Bayesian network;interval algebra198|2|7更新时间：2025-07-02
- 摘要：Conventional compressive sensing (CS) imaging methods rely on the assumption that all scatterers in the imaging scene are located exactly on the pre-defined grids.However, since the scatterers are distributed in a continuous scene, the off-grid problem inevitably exists, which makes basis mismatch between echo measurement and the assumed sensing matrix, and leads to considerable performance degradation by CS-based methods.Therefore, this paper investigates the sparse imaging for off-grid target in frequency diverse multiple-input multiple-output (FD-MIMO) radar.A sparse autofocus imaging method based on Bayesian compressive sensing (SAF-BCS) is proposed.It employs the technique of variational Bayesian inference to achieve the imaging of off-grid scatterres in light of the criterion of maximum a posteriori (MAP).Compared with the conventional sparse recovery algorithms, the proposed method adequately utilizing the prior information of the target, is able to automatically tune parameters, and thus can provide a better capability to correct the off-grid errors, and to estimate the noise power, etc.Simulation results confirm that SAF-BCS is not sensitive to grid discretization, and has a robust imaging performance.关键词：Bayesian compressive sensing;FD-MIMO radar;off-grid target;variational Bayesian inference;sparse autofocus imaging292|2|6更新时间：2025-07-02
- 摘要：Spatial modulation (SM) is a special multi-antenna transmission technology, where the transmit antenna index is exploited to convey information except for modulation signals.In order to obtain transmit-diversity gains, antenna selection technology is introduced in SM systems to increase its demodulation performance.In antenna selection technology, Euclidean distance antenna selection (EDAS) is widely applied.However, its exhaust-search detection has extremely high complexity, which limits its application.Thus, exploiting the characteristics of modulation symbols and 2-D quantization, two low-complexity and optimal antenna selection algorithms are proposed.The simulation results show that the proposed algorithms reduce the computational complexity meanwhile achieving optimal performance.关键词：spatial modulation (SM);antenna selection;low complexity.242|3|5更新时间：2025-07-02
- 摘要：Based on frame slotted ALOHA algorithm, a grouped adaptive allocating slots (GAAS) anti-collision algorithm is presented to solve the problem of collision between the reader and multi-tag in radio frequency identification (RFID) system. First, the reader needs to obtain the time slots chosen randomly by tags and send the results to each tag; then the tags rectify the time according to the instruction; moreover, the reader skips free and collision time slots, and adaptively distributes valid ones; finally, the tags are quickly recognized in GAAS. When the number of unidentified tags is very large, the tags are grouped and the frame sizes are adjusted dynamically to reduce the processing time. The simulation results show that GAAS has higher identification efficiency and stability, and lower cost of communication. Particularly, when the number of tags is over 1000, the throughput rate still maintains above 71%. Compared with the framed slotted ALOHA-256 algorithm and the grouped dynamic framed slotted ALOHA algorithm, the proposed algorithm enhances the system efficiency by 300% and 97.2% respectively.关键词：RFID;ALOHA algorithm;tags grouping;throughput rate;adaptively allocating slots200|3|6更新时间：2025-07-02
- 摘要：Estimating of geometrical theory of diffraction (GTD) model parameters accurately and efficiently is significant for automatic target recognition.In this paper, a time-domain sparse component analysis method is designed for parameter estimation of GTD model.Firstly, potential locations of scattering centers, as well as columns of the dictionary, are reduced according to the high resolution range profile.Secondly, the time domain responses of GTD model is used to construct the dictionary, and the small amplitude areas are cut off.Compared with the presented method, not only columns of the new dictionary are reduced, but also the dictionary becomes a sparse matrix.As a consequence, it needs less memory to store, which is helpful to decrease computational complexity of component analysis.In addition, a reconstruction method based on the orthogonal matching pursuit is designed for our dictionary.Finally, experimental results demonstrate the performance and efficiency of the proposed method.关键词：GTD model;parameter estimation;sparse component analysis;time domain sparse181|2|0更新时间：2025-07-02
- 摘要：The points of spatial dataset usually consist of the spatial information and the described text information.The problem of approximate string reverse furthest neighbors search (ASRFNS) query is defined to search all points in a spatial dataset that take the given query point as its furthest neighbor while their text satisfies the string similarity constraint.Based on the existing reverse furthest neighbors search algorithm and approximate string search algorithm, we proposed two solution algorithms:the convex hull furthest cells join algorithm (CHFCsJoin) and the convex hull furthest cell approximate string serial search algorithm (CHFCASSS).In order to further improve the query performance, we also proposed an efficient algorithm of the convex hull furthest cell filter-Rtree (CHFilterRtree) which contains disk resident structure of space and keyword information.With the real dataset experiments and analysis, the results demonstrate that our proposed algorithms obtained a good performance.关键词：approximate string search;reverse furthest neighbors search;spatial database;disk resident index203|2|1更新时间：2025-07-02
- 摘要：A new unsupervised color segmentation method based on region-constrained EM (Expectation Maximization) and graph cuts is proposed, which can automatically determine the number of segments for a color image.The proposed method first obtains the superpixels of the image and extracts CIE Lab color feature and multi-scale quaternion Gabor filter feature.In order to automatically and efficiently determine the number of segments for the image and avoid the problem caused by using superpixels directly, a window is used to sample each superpixel to obtain a pixel subset which represents the superpixel.Then the feature space of the sampled pixel subsets is modeled with Gaussian mixture model, and the model parameters (including the number of components) are obtained by a region-constraint component-wise EM algorithm.Finally, the segmentation result can be obtained by α-expansion with the learned model parameters.Experimental results demonstrate the good performance of the proposed method.关键词：color image segmentation;region constraint;superpixel;component-wise EM;graph cuts216|2|2更新时间：2025-07-02
- 摘要：Visual tracking is a core technology for the application domains of intelligent monitoring, robotics and vision navigation, etc.Aiming at the problem of high complexity and poor real-time performance in the existing quasi-sequential Monte Carlo tracking algorithms, this paper presents a method based on multilevel dynamic layer representations, which simulates the posteriori probability of a state using more reliable and effective particles.Then a sampling strategy is proposed in confidence areas derived from the detector, in which each particle represents a dynamic representation and has a two-layer motion model.The observation model based on parted-mean-shift is constructed for space and appearance information.Depending on the degree of matching sub-blocks, the weight of particles is calculated and a way to detect the occlusion state of an object is put forward for realtime model update.Experimental results using challenging public video sequences show better accuracy and efficiency of the proposed method, compared with the classical particle filter and mean-shift algorithms, etc.关键词：visual tracking;confidence region;two-layer multilevel motion model;block-based observation model;model update318|2|1更新时间：2025-07-02
- 摘要：The relationship strength model between social network nodes is the key of social networks service such as information dissemination researches and recommendation system.The traditional researches focus on modeling simple binary relations and static relations, without considering dynamic attenuation of user interaction effects.Aiming at this problem, this paper proposes a social networks user relationship strength model based on Hawkes process(HP-URS), which takes the relationship strength, similarity and history interaction behavior between users as a latent factor, latent factor incentive and presentation respectively.This model uses Hawkes process to characterize relationship between history interaction behavior and user relationship strength.This model provides a solution of the disadvantages of the original model without considering user history interaction effects and their attenuation.This paper uses the data from microblog social networks evaluating HP-URS model, and the experimental results show that this model can improve relationship strength prediction accuracy and coverage rate of the Top-N neighbor nodes based on relationship strength.关键词：social networks;Hawkes process;relationship strength prediction;microblog460|3|6更新时间：2025-07-02
- 摘要：The localization methods based on signal amplitude are widely used in radio frequency based location system, wireless sensor network and acoustic location system.The conventional gain ratios of arrival (GROA) passive localization methods take no consideration of the altitude of the source, though it is usually known.A GROA model with known altitude of the source was proposed, and the Cramer-Rao low bound (CRLB) was also derived.And then, a localization algorithm based on Newton iteration was proposed and it was proved theoretically to reach the CRLB under the Gaussian noise data model.The simulations validated the theoretical conclusions.This algorithm was also verified in a wireless monitoring network.In conclusion, this algorithm can accurately localize the source with known altitude.关键词：GROA;passive localization;known altitude;CRLB;Newton iteration282|3|0更新时间：2025-07-02
- 摘要：For the problem that falls often seriously jeopardize to the health of the elderly, this paper designs a fall detection method based on EMG signals.Firstly, the feature of fuzzy entropy is extracted from the sEMG on the gastrocnemius and vastus lateralis muscle.Then, the weighted kernel Fisher linear discriminant analysis is proposed for the dataset imbalance problem that the number of activities of daily life (ADL) is far more than the fall, and the samples nuclear matrix is adjusted by the appropriate balance parameters.Finally, the fall is identified from walking, squat and sit down by this method.The experimental results show that the method has 96.7% fall and 99.4% ADL average recognition rate, and is better than the other classification methods.关键词：fall detection;surface electromyography (sEMG);fuzzy entropy;weighted kernel Fisher linear discriminant analysis (weighted kernel FDA);pattern recognition179|2|4更新时间：2025-07-02
- 摘要：When performing dimensionality reduction with linear projections, maximum margin criterion (MMC) is often affected by outliers and noises due to L2-norm.In this paper, L1-norm-based maximum margin criterion (MMC-L1) is proposed for dimensionality reduction.It makes full use of Maximum Margin Criterion and strong robustness of L1-norm to outliers and noises.A rapid iterative optimization algorithm, with its proof of monotonic convergence to local optimum, is given.Experiments on several public image databases verify the robustness and efficiency of the proposed method.关键词：maximum margin criterion (MMC);L1-norm;linear projection;dimensionality reduction222|2|0更新时间：2025-07-02
- 摘要：In this paper the nonlinear stochastic differential equation is used to generalize an intermittency signal, and the correlation of its 1/f noise characteristics under the wavelet bases with different vanishing moments are analyzed.The simulation results show that in the middle band of the frequency spectrum, its power spectrum density (PSD) shows typical 1/f noise characteristics, and the relationship of the signal's wavelet transformation coefficient variance and the corresponding wavelet scale is linear under logarithm coordinate.In this frequency band, under some scales the signal's wavelet transformation coefficient correlations decrease with the vanishing moments growing, while in other scales, the correlations increase with the vanishing moment increasement.These results indicate that wavelet transformation does not always bring decorrelation to the intermittency signal.The relationship of the wavelet transformation coefficients' variances and the scale, and the tendency of coefficients' correlations with wavelet vanishing moments changing are analyzed.关键词：intermittency;1/f noise;wavelet transformation;correlation188|2|2更新时间：2025-07-02
- 摘要：Automatic identification and tracking for specific building areas is not only of great significance in airborne remote sensing video data processing, but also one of the key technologies for task-oriented non-hovering airborne platform to search ground and boost fire control system.This paper proposes an identification and tracking algorithm of specific building areas for real complex application scenes.First, to extract local descriptors for offline reference images with target areas.At the stage of target area online identification, in order to ensure the timeliness, a fast SIFT (Scale Invariant Feature Transform) feature extraction method based on significant edges is proposed to extract local descriptors for suspected areas in large field of view images to be detected.In addition, the hierarchical feature point matching method is designed to achieve a highly reliable identification of target areas.At the stage of online tracking for target area, adaptive window and trajectory predicting technologies can effectively delineate suspected target areas, and within the limited range to recognize the final targets and track them.Real-measured data simulation results show that the proposed algorithm in complex scene conditions can realize the quick identification and stable tracking for a particular building area.It can also provide a key technical support for the future application of real systems.关键词：airborne video tracking;building area identification;local descriptor;complex scenes162|3|1更新时间：2025-07-02
- 摘要：The existing cooperative routing algorithms ignored channel assignment issue in multi-radio wireless mess network.To provide high performance service for concurrent flows, this paper combined both multi-radio multi-channel technique and cooperative communication technique to reduce co-channel interference and obtain cooperative diversity gain.Based on virtualized representation method for the cooperative communication module, this paper simplified the problem of joint cooperative routing and channel assignment to the problem of joint direct routing and channel assignment, and modeled the problem as a mixed integer linear programming, and proved it NP hard.In order to solve the problem, this paper further proposed a loose joint cooperative routing and channel assignment algorithm (L-JCRCA).The simulation results show that L-JCRCA can promote network throughput effectively.关键词：wireless mesh network;cooperative routing;channel assignment240|2|1更新时间：2025-07-02
- 摘要：Cognitive radio can improve the spectrum efficiency by fusing with technologies such as multi-input multi-output (MIMO), orthogonal frequency division multiplexing (OFDM), ultra wideband (UWB), cooperative communication, etc.Cognitive MIMO is a fusion technology of cognitive radio and MIMO, which has advantages of interference suppression, anti-multipath fading, spatial diversity, and multiplexing.However, there is intercoupling among its precoding matrices because of the interference temperature constraint in underlay sharing mode, which makes it difficult for the cognitive MIMO in the underlay interference network to obtain optimal transmitting performance.Consequently, an optimal interference align algorithm for cognitive MIMO interference network is proposed to obtain the optimized interference network transmitting performance, in which the iteration relationship between the optimal transmitting and receiving matrices is derived by interactively and alternately using transmitting precoding and receiving interference subspace matrix, and the derivation process is based on Rayleigh-Ritz theorem and convex optimization theory.In order to remove the interference temperature constraint, the Lagrange partial of dual-decomposition was exploited, and the sub-gradient projection method was adopted to update the Lagrange variable, which overcame the shortcoming of decreasing transmitting rate caused by ignorance of the matrix rank constraint in the existing semi-definite relaxation algorithms.The validity of this algorithm is verified by theoretical analysis and numeric simulations, and results also indicate that the proposed algorithm is capable of maximizing the cognitive MIMO interference network available transmitting rate.关键词：cognitive multi-input multi-output (MIMO);underlay spectrum sharing;interference network;interference alignment;Lagrange partial dual2|2|2更新时间：2025-07-02
- 摘要：When lung nodules are detected in lung CT by computers, the vessel cross section and lung nodule have similar imaging characteristics in the two-dimensional CT image sequence, resulting in unable to detect problems precisely.We employed a new strategy for the lung nodules detection algorithm, which is based on the Gestalt psychology.This method can detect lung nodules indirectly by removing blood vessels.The experimental results show that, this algorithm can effectively reduce the influence of blood vessels on lung nodule detection, so as to improve the accuracy of detection of lung nodules.关键词：Gestalt principles;blood;lung nodules2|3|4更新时间：2025-07-02
- 摘要：Aimed at the high energy consumption and communication delay due to multi-hop wired links between distant cores of traditional and large-scale network-on-chip(NoC), a virtual Torus-based adaptive wireless NoC(VT-AWiNoC) structure is proposed.The automatic detection and dynamic bandwidth allocation mechanism to hot wireless link based on the sensing parameter for link congestion measurement is adopted.Moreover, the dynamic allocation circuit for transmitter is designed to realize adaptive adjustment of the intra-chip topology and link bandwidth as different traffic patterns.We compare the performance of our proposed VT-AWiNoC to other hybrid wireless NoC topologies by setting up the energy consumption and delay estimate models.Experimental results show that the proposed topology obtains a delay improvement of 16.52% to 23.27% under random traffic pattern, an energy saving per packet of 39.19% under hotspot traffic pattern, a delay improvement of 17.20% to 21.68% and energy saving per packet of 23.49% on real application such benchmark as FFT(Fast Fourier Transform).The proposed topology achieves higher performance gains with small additional area cost.关键词：wireless network-on-chip(WiNoC);adaptive topology;congestion measurement2|2|5更新时间：2025-07-02
- 摘要：An algorithm of adaptively cooperative spectrum sensing based on optimal relay was proposed, which can overcome the problems about fading of sensing channel and huge consumption of relaying.This algorithm was based on the consideration of sensing performance and energy consumption and obtained optimal tradeoff between performance and consumption by opportunistic relaying, benefit function based selection of optimal relay and mechanism of system parameters adjustment.Meanwhile, detailed theoretical formulas and performance analysis of the algorithm were given.And the comparative simulation of sensing performance of non-relay cooperative sensing algorithm, optimal relay fixed cooperative sensing algorithm and this algorithm under different system parameters were done as well.The results show that the proposed algorithm has certain advantages.关键词：cognitive radio;spectrum sensing;opportunistic relaying;optimal relay;parameters adjustment2|2|2更新时间：2025-07-02
- 摘要：To preserve the privacy of social networks, most existing methods are applied to satisfy different anonymity models, but some serious problems are involved such as often incurring large information losses and great structural modifications of original social network after being anonymized.Therefore, an improved privacy protection model called SimilarGraph is proposed, which is based on k-degree anonymous graph derived from k-anonymity to keep the network structure stable.Where the main idea of this model is firstly to partition network nodes into optimal number of clusters according to degree sequences based on dynamic programming, and then to reconstruct the network by means of moving edges to achieve k-degree anonymity with internal relations of nodes considered.To differentiate from traditional data disturbing or graph modifying method used by adding and deleting nodes or edges randomly, the superiority of our proposed scheme lies in which neither increases the number of nodes and edges in network, nor breaks the connectivity and relational structures of original network.Experimental results show that our SimilarGraph model can not only effectively improve the defense capability against malicious attacks based on node degrees, but also maintain stability of network structure.In addition, the cost of information losses due to anonymity is minimized ideally.关键词：social network;privacy preservation;k-degree anonymity;information loss2|2|4更新时间：2025-07-02
- 摘要：The radiation effect of FP-GaN HEMT was investigated by using proton radiation source.After low irradiation fluence, the phenomena of an increase in carrier density of GaN material was found.The device showed negligible degradation at low proton fluences.At high fluences, the decreased drain current and transconductance as well as the obviously shifted threshold voltage of HEMT were observed.And the ohmic contact was so relative robustness to proton, but the Schottky characteristics degraded obviously.Utilizing the depletion approximation theory and the introduction of acceptor defects to express radiation induced defects in AlGaN/GaN heterostructures, we developed irradiation induced acceptor defects damage model for AlGaN/GaN HEMT.The simulations indicated that the acceptor defects induced in both channel and buffer layer dominate the radiation damage in AlGaN/GaN HEMT.A good agreement between calculations and experiments presents the validity of this model.The annealing results proved that the damage induced by proton may be partially recovered.SiN-passivated FP-AlGaN/GaN HEMTs appear to be attractive candidates for space and terrestrial applications, and the HEMTs are resistant to displacement damage.关键词：AlGaN/GaN HEMT;proton-irradiation;irradiation induced acceptor defects;radiation hardness4|4|2更新时间：2025-07-02
- 摘要：In order to give a complete signal detection and estimation method based on Duffing system, this paper uses the coupling Duffing oscillator, and introduces the variable scale method, to detect and estimate the sinusoidal signal with unknown frequency and arbitrary phrase just by one Duffing oscillator.Besides, this paper puts forward a simplified method which is based on chaotic oscillator for estimating the amplitude and phase of the signal to be measured, and integrated method principle and the simulation experiment result proves that this method has high estimation precision, strong ability to resist noise interference and the advantages of good real-time performance.Finally, using a simulation result of a analog signal for verifying the availability and accuracy of the detection and estimation method is proposed.关键词：chaotic oscillator;variable scale;sine signal detection;low signal to noise ratio;high precision estimation2|3|11更新时间：2025-07-02
- 摘要：The existing methods for analyzing non-stationary signal all have different defects.The time-frequency resolution of short-time Fourier transform is limited by the uncertainty principle.The boundary effect and mode mixing of Hilbert-Huang transform often result in an unclear time-frequency distribution.Analytical mode decomposition is only suitable for analyzing multi-component signal with constant frequencies.For the multi-component signal with time-varying frequencies, especially when the spectrum overlaps, a method termed generalized analytical mode decomposition (GAMD) is proposed for analyzing these signals.In GAMD, generalized Fourier transform is used to convert the time-varying frequencies to constant ones without overlapping in spectrum and then the analytical mode decomposition is adopted to handle the transformed signal.Lastly, the inverse generalized Fourier transform is used to demodulate the obtained mono-components.Hence, GAMD is very suitable for analyzing time-varying non-stationary signals.The proposed GAMD method is compared with short-time Fourier transform and Hilbert-Huang transform through analyzing simulation signals and the results indicate that GAMD possesses more accurate decomposing results and higher time-frequency resolution.关键词：time-frequency analysis;generalized Fourier transform;analytical mode decomposition;empirical mode decomposition;non-stationary signal2|3|2更新时间：2025-07-02
- 摘要：Community detection is an important and crucial issue in social networks.Using different objects' information can help detect the community structure.However, many existing community detection methods are hardly applied in heterogeneous networks.To address the above problem, we propose a semantic-path based community detection method.This method first calculates the similarity matrix based on semantic paths, obtaining the reliability matrix to build a graph regularization term.Then the nonnegative matrix factorization is employed to achieve the community detection in heterogeneous networks.Simulation on real web data demonstrates that our proposed algorithm can detect the community structure in heterogeneous networks.关键词：heterogeneous network;community detection;semantic path;nonnegative matrix factorization2|4|3更新时间：2025-07-02
- 摘要：According to the characteristics of differential evolution, a multi-objective evolutionary algorithm based on dynamic population multi-strategy differential models and decomposition (MOEA/D-DPMD) is proposed to solve the expensive problems.The algorithm divides the population into three sub-populations and each sub-population is corresponding to a differential evolution strategy.In order to improve the performance of the algorithm, the size of sub-population is adjusted dynamically on the basis of a differential evolution strategy contribution.Each strategy is adopted to participate in coordination during the evolution process.Through the test simulation on the LZ09 benchmarks with complicated Pareto Set (PS), MOEA/D-DPMD shows a best performance with a neighborhood size of 25.Via the comparative analysis of different schemes of differential strategy, MOEA/D-DPMD also performs well.The experimental results indicate that MOEA/D-DPMD has a better performance in terms of convergence and diversity compared with MOEA/D and NSGA-II, which is an effective way for solving complex multi-objective optimization problems.关键词：decomposition mechanism;multi-strategy differential evolution;dynamic population;multi-objective optimization2|2|12更新时间：2025-07-02
- 摘要：Multimodal optimization aims to search multiple optima (global and/or local optima) simultaneously, which gives rise to a challenging task for traditional optimization algorithms.This paper proposes a two-stage algorithm to solve multimodal optimization problems.In the first stage, NCDE with neighborhood mutation strategy tries its best to find as many approximate positions of optimal solutions as possible on the fitness landscape.After NCDE runs a certain number of iterations, DMC method is employed to divide the entire population into multiple clusters, and then CMA-ES algorithm is used to perform fine search on each cluster which is found by NCDE.Additionally, search point replenishment strategy is put forward to balance cluster size and to increase search capability of our algorithm in the beginning of the running.Extensive comparative experiments is made between our proposed approach and 9 state-of-the-art algorithms on two benchmark sets, the results show that the new algorithm is effective and superior to the other algorithms on the majority of test functions.关键词：crowding differential evolution;covariance matrix adaptation evolution strategy;multimodal optimization;niching;neighborhood mutation2|2|0更新时间：2025-07-02
- 摘要：An encoder rate control algorithm is proposed for the distributed residual video coding, which is based on scrambling the pixels of a residual frame with pseudo-random code in order to realize rate estimation at the fame level, i.e., estimating one rate for each residual frame.A quantization index estimation algorithm is also proposed to increase the ratio of successful decoding and solve the problem of rate underestimation.In the mean time, the statistical characteristics of the residual signal at the encoder can approximately represent the correlation between the signals at both the encoder and the decoder.No predicted side information needs to be generated at the encoder.The simulation results show that the proposed algorithm has low encoder complexity, high successful decoding ratio, less latency, and good RD performance.关键词：distributed residual coding of video;encoder rate control;scrambling with pseudo-random code2|2|3更新时间：2025-07-02
- 摘要：The research of the cognitive radio networks is facing rigorous challenges with the insufficience of the radio spectrum resources and multi-user contention environment.The fundamental principles of the spectrum handoff was elaborated, including the concepts and characteristics of the spectrum handoff, the classification of the proactive and reactive decisions of the spectrum handoff, spectrum handoff process abstract modeling methods, etc.Then five spectrum handoff algorithms based on the probability theory, Markov process, queuing theory, fuzzy logic, fuzzy neural network, were summarized, which were mainly on the ground of mathematic modeling tools.Some significant research findings of each spectrum handoff algorithm in the academic circle were reviewed.Finally, on account of the analysis of the existing algorithms and research achievements, some important problems of imperfect spectrum detection, target channel selection, idle channel dynamic character that were existed in the current research were summarized and the future research direction of the spectrum handoff were predicted.关键词：cognitive radio networks;spectrum handoff;handoff approach;handoff process;abstract approach2|2|8更新时间：2025-07-02
- 摘要：Bayesian network is one of the main tools for data mining.In such cases as large equipment fault diagnosis, geological disaster forecast, operational decision, etc, good results are expected to achieve based on small data sets.Therefore, this article focuses on the problem of learning Bayesian network from small data sets.Firstly, the structure constraint model based on the probability distribution of the connection was built.Then, the improved-Bayesian Dirichlet-binary particle swarm optimization algorithm was proposed.Secondly, the monotonicity parameter constraint model was defined and the monotonicity constraint estimation algorithm was proposed.Finally, the proposed algorithm was applied to construct the threat assessment model.Then, the model was used for reasoning with the variable elimination method.Experimental results reveal that the structure learning algorithm outperforms classical binary particle swarm optimization algorithm and the parameter learning method surpasses maximum likelihood estimation, isotonic regression and convex optimization method for small data sets.The threat assessment model is also proved to be effective.关键词：Bayesian network;small data sets;binary particle swarm optimization;threat assessment2|2|7更新时间：2025-07-02
- 摘要：A polarimetric active radar calibrator (PARC) is used to calibrate wideband high-resolution radars, confirming the high-resolution imaging can accurately characterize radar targets.However, the PARC is an active component and induces additional distortion, affecting the system distortion compensation.This paper was based on the "method of paired echoes" and the distortion compensation in the frequency domain.After transforming the frequency compensation into the filtering in the time domain, we proposed to intercept the time filter for modifying the PARC distortion.The experimental results based on real radar data confirm the accuracy of the theoretical analysis and the proposed modification method and after the modification the PARC can approximately compensate the system distortion.关键词：wideband high-resolution radar;Calibration;high-resolution imaging;radar target;active component;distortion compensation;echo2|2|1更新时间：2025-07-02
- 摘要：The traditional ship detection algorithms, such as 2L-IHP (Two Looks Internal Hermitian Product), Pol-IHP (Polarimetric Internal Hermitian Product), etc, usually utilized two sub-look images cross-correlation to decrease omitted detection for small ships.However, because they were constrained by the number of sub-look images, the previous methods could not increase ship-sea contrast to much extent, which affected the ship detection accuracy.Therefore, this paper proposes a detection algorithm based on generalized multi-sublooks correlation using polarimetric SAR (POLSAR) data.Firstly, the sub-look decomposition method is applied for POLSAR data to get multi-sublook POLSAR images.Then the correlation matrix and the coherence operator based on the generalized similarity parameter (GSP) are defined to calculate the coherence image of the multi-sublook images.Finally, the constant false alarm rate (CFAR) detection method is utilized for ship detection by the calculated cumulative distribution function (CDF) of the coherence image.The experiments prove that ship-sea contrast can be increased with the number of sublook images by the propose method, which reduces the undetected probability of the ships and also improve the ship detection accuracy significantly.关键词：polarimetric SAR;multi-sublooks correlation;generalized similarity;constant false alarm rate;ship detection2|2|1更新时间：2025-07-02
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