最新刊期
卷 45 ， 期 8 ， 2017
- 摘要：Analyzing the primary noise of an ANC system which contains narrowband cyeference signal,nonlinear primary path and non-minimum phase secondary path,and exploring the feedback structure based on FIR filter and the feedforward structure based on FLANN filter.By discussing the advantage and the disadvantage of these two structures,we proposed a new hybrid structure in this paper.Proposed FLANN-FIR structure composites the advantages of feedforward and feedback structures,not only the predictable noise can be reduced,but also the unpredictable noise can still be suppressed.Simulations under the cases of different signal noise ratio and different nonlinear primary path demonstrate that proposed hybrid structure performs best on the convergence rate and steady-state property.关键词：narrowband active noise control;nonlinear path;non-minimum phase;functional link artificial neural network;feedback prediction102|673|6更新时间：2025-07-16
- 摘要：In the deep sub-micron technology domain,the energy consumption of data bus accounts for the energy consumption proportion of embedded multi-core chip is increasing.FV-MSB method was used to reduce the off-chip data bus energy consumption.However,it didn't deal with the non-frequent values and the lower parts of the frequent high-ordered bits values.In order to further reduce the dynamic energy consumption of which is induced by these values on the bus,an energy saving method based on frequent values and bit switching-aware for on-chip data bus is designed.Using the frequent values and the perception of the switching activities number,automatically selecting the encoding mode and so switching activities on the bus are significantly reduced,and therefore the bus dynamic energy is effectively reduced.With 70 nm technology,the results of simulation experiments show our method can improve the ratio of energy saving by about 17.76% and average ratio about 16.91%,and which is better than FV-MSB over 6.28%.And the trend of the energy saving ratio with λ shows that the method can still play the role when the technology size is further reduced in the future.关键词：frequent exchanged value;frequent value cache;bus energy consumption saving;invert encoding;coupling capacitance118|455|0更新时间：2025-07-16
- 摘要：The paper describes our thoughts of forming the system time of a Global Navigation Satellite System (GNSS),which is denoted by GNSST,and the time references TA(k) and UTC(k) of a timing laboratory where k characterizes the specific national laboratory.We also describe the roles of time scale algorithms,clock steering algorithms,and clock prediction algorithms in forming these time scales.We take Chinese Beidou satellite navigation system time (denoted BDT) as an example,and propose a twice steering algorithm to form BDT.We take the national time service center (NTSC) of China as an example to describe the idea,method,principle and theory of forming a TA(k) and a UTC(k).Then we analyze the impact of TA(NTSC) on UTC(NTSC),and the impact of UTC(NTSC) on the time synchronization precision and frequency stability performances of BDT if we steered BDT to UTC(NTSC).We also propose an idea of steering BDT to a paper time scale formed from UTC(NTSC) and UTC(BSNC).The performance is theoretically analyzed.关键词：GNSS;timing laboratory;time reference;TA(k);UTC(k);time synchronization precision;frequency stability96|414|7更新时间：2025-07-16
- 摘要：A small baseline stereo matching method based on extended phase correlation is proposed to obtain high precision sub-pixel disparity for small baseline photogrammetry.The multi-step strategy is adopted in this method.Firstly,the integer pixel disparity is calculated by an adaptive support window local matching method.Then the relationship of corresponding points is established under the guidance of integer pixel disparity.The sub images are extracted through selecting the corresponding points as the center.Finally,the sub-pixel disparity is obtained by matching the sub images utilizing an extended phase correlation matching method.The experiments are carried out by using the small baseline stereo image pair and artificial synthesis stereo image pair with sub-pixel disparity,the results show that the small baseline stereo matching method based on extended phase correlation has superior performance on precision and efficiency.关键词：stereo matching;small baseline;phase correlation;sub-pixel disparity127|356|5更新时间：2025-07-16
- 摘要：There is great significance in lie detection for the criminal investigations and law trials.In this study,according to the nonlinear characteristics of electroencephalography (EEG),it is the first time to use the sample entropy (SE),a nonlinear dynamical parameter of EEG,to see if someone is lying.The sample entropy values of 30 subjects' EEG signals in lying or honesty states were calculated and analyzed.The study found that the fluctuating range of SE values in honesty was obviously less than that in lying.It is more important that the SE values in lying was significantly higher than the honesty,which indicated that SE could be used to distinguish EEG signals between two different states of honesty and lying.This research provides a new way for EEG-based lie detection.关键词：lie detection;electroencephalography(EEG) signals;nonlinear characteristic;sample entropy113|407|9更新时间：2025-07-16
- 摘要：Based on evaluation state theory of residuated lattice and by defining probability measure in set of all evaluation states of residuated lattice and set of all formulate respectively,the probability truth degree of formula in residuated lattices semantics is introduced using the integral method,then the probability logic metric space is established in residuated lattices semantics,the approximate reasoning of quantitative logic methods have been entended to residuated lattices semantics,the feasible graded method of residuated lattices semantics is provided.关键词：residuated lattice;evaluation state;probability truth degree;probability logic metric space;approximate reasoning215|336|3更新时间：2025-07-16
- 摘要：To improve convergence and diversity of particle swarm optimization(PSO),an improved PSO which called regional-segmentation self-adapting variation particle swarm optimization (RSVPSO) algorithm is introduced.Regional-segmentation is adopted in the algorithm,using information cross between particles,narrow search region quickly; combining with self-adapting variation strategy in late iterations at the same time,improved capacity of jumping out local optimum trap and enhanced the diversity of particles,reach the goal of optimization.The proposed algorithm is applied to eight test functions and compared with the elite immune clonal selection co-evolutionary particle swarm optimization and so on.The results show that the proposed algorithm has considerable improvement in the convergence speed,search accuracy,optimum efficiency and so on.关键词：regional-segmentation;information cross;self-adapting variation;diversity207|543|7更新时间：2025-07-16
- 摘要：Unmanned aerial vehicle system (UAVS) cooperative combat model with temporal constraint of task type is insufficient making decision by single objective optimization.The multi-objective multi-strategy fusion quantum particle swarm optimization (MSQPSO) algorithm was proposed.To establish the task allocation model more accord with the actual operation situation,adding temporal constraint of task type and multi-UAV cooperative constraint,and abstracting the various capabilities of UAV.The quantum particle swarm optimization was improved by good-point set theory,scale chaos factor,quantum mutation and dynamic inertia weight.The multi-objective optimization was adopted to make decision.The final simulation results verify the effectiveness and superiority of the proposed MSQPSO algorithm.关键词：unmanned aerial vehicle;multi-task allocation;multi-objective optimization;quantum particle swarm;multi-strategy fusion219|441|8更新时间：2025-07-16
- 摘要：Stochastic resonance provided new ways detecting weak communication signals.A new method based on artificial-fish swarm optimization is proposed whose emphasis is on weak periodic signal detection based on stochastic resonance.Artificial-fish swarm optimization is combined with normalization of stochastic resonance.Noise is utilized by adding it to the signal while new adaptive step strategy and iteration stopping strategy are also used.The results of theoretical analysis and simulation experiments show this proposed method have great promotions on adaptability,stability,precision of the optimal resonance and the convergence speed,as well as a great promotion of 3-5dB on SNR gain compared with traditional stochastic resonance based on swarm optimization.Meanwhile,the time complexity of calculation is decreased by 70%.关键词：stochastic resonance;artificial-fish swarm optimization;normalization method;adaptive step98|355|14更新时间：2025-07-16
- 摘要：Multiple Supply Voltage (MSV) design is an effective ways to deal with SoC power challenge,but brings overhead on wirelength area,etc.To reduce wirelength,chip's dead space ratio and improve algorithm speed,an improved fixed outline multi-voltage floorplanning algorithm is proposed.For a given floorplan solution represented by NPE (Normalized Polish Expression),We use the shape curve adding algorithm to calculate its optimal floorplan implementation,and adopt an incremental calculation method in the process of NPE calculation and voltage assignment to reduce runtime.An improved objective function including fixed-outline constraint is proposed,and the IAD (Insertion After Delete) operator is used to post-optimize the obtained floorplan of SA.Experimental results show that compared with the existing methods,our algorithm has advantages on wirelength and dead space ratio,and all circuits achieve extremely low dead space ratio (<<1%) under different aspect ratio and different voltage island number.关键词：low power;multiple supply voltage;floorplanning;fixed-outline162|372|0更新时间：2025-07-16
- 摘要：In order to solve the problem that current coding schemes lost consistence between similar local features,this paper proposes a new graphically regularized coding algorithm.This algorithm used any current coding scheme to get the initial coding coefficients,and utilized a regularized term to preserve locality constrains both in the feature space and the spatial domain of the image.Experimental results on popular benchmark datasets show that our method improves the performances of the current coding algorithms,and the average classification accuracies of our proposed method in MSRcv2,Caltech101,Scene15,Indoor 67 and UIUC-sport has reached 91.13%,76.02%,83.76%,44.78% and 89.05% respectively.关键词：bag-of-feature;coding algorithm;graphical model;image classification112|495|1更新时间：2025-07-16
- 摘要：Concerning low efficiency detection for foggy density in traffic image,a novel algorithm was proposed to check foggy density based on distribution characteristics of natural statistics.Firstly,foggy images were partitioned as P×P pixel patches by method of the maximum overlap count.Secondly,featured function vector for local contrast and entropy was created and maximum likelihood estimation between tested image and two standard image corpuses were respectively computed.Finally,Mahalanobis-like Distances(MD) between foggy image and corpus of standard foggy image or fog-free image were achieved,and the ratio of two values could be used to measure the foggy density.Simulation shows that the value D can respond the varied tendency to density for same scene with difference density or different scene with different density.Correlation coefficient up to 0.97 between this algorithm and mean opinion scores (MOS) method indicate high linear about them and the coefficient is larger than 0.56 between mean subtracted contrast normalized (MSCN) and MOS.Comparison to PM2.5 shows that this algorithm can be used to evaluate the level for fog density.关键词：fog;image processing;density;contrast;entropy141|385|7更新时间：2025-07-16
- 摘要：A fast and effective single image dehazing algorithm is proposed in order to solve the problems of low efficiency and the color distortion of the bright grey areas after dehazing algorithm of using dark channel prior.First,the algorithm estimates the rough transmittance and the atmospheric light based on HSI color space.Then,the final transmittance is generated after smoothing the rough transmittance by guided filter and correcting the transmittance of the bright grey areas by a threshold method.Finally,tone mapping are used to get the restored image.Experiments show that the proposed algorithm has high efficiency,which can effectively improve the visibility and contrast of the restored image.关键词：image dehazing;dark channel prior;HSI color space;atmospheric scattering model335|644|13更新时间：2025-07-16
- 摘要：To address detection difficulty caused by complex scene and the deformation of the object,the salient contour of image based method is proposed in this work.Firstly,the outline of image is extracted by Globalized probability of boundary,and then the improvement of the Otsu for adaptive threshold processing is used to attain the salient contour.Next,the robust fan shape model of the object is constructed by detecting and removing the unstable contour of the object.Finally,three similar matching strategies are proposed by jointing several local and global features of contour.They are based on the features probability density distribution and can detect object,its mirror flip and rotated object,respectively.Through the experimental analysis of multiple databases,the proposed method can effectively detect object and its mirror flip,and at the same time,it can also effectively detect the rotated object in the small range of rotation angle.关键词：contour extraction;fan shape model;shape matching;object detection165|716|10更新时间：2025-07-16
- 摘要：The watershed algorithm can conduct region-based image segmentation effectively and accurately,but it tends to cause over-segmentation.To tackle the above mentioned problem,an improved watershed algorithm is proposed,as follows:first of all,the color gradient is computed using spectrum envelope filtered color image,based on which,regions with minimum gradient are marked using self-adaptive H-minima transformation method.Then,the watershed transform is applied to segment the marked gradient image.Finally,affinity propagation clustering is adopted to merge the regions segmented by the watershed transform,using color moments computed on each local region,to get the final segmentation result.Experiments conducted on public available datasets demonstrate the adaptability and robustness of proposed algorithm,compared with the relative state-of-the-art methods.The proposed method can solve the over-segmentation problem well and get accurate results.关键词：watershed algorithm;self-adaptive marking;affinity propagation;image segmentation;over-segmentation244|424|11更新时间：2025-07-16
- 摘要：In recent years,CT imaging technique has been widely used in clinical medicine domain.However for the patient with metallic implants,there is most likely bright and dark artifacts around metal objects due to beam hardening and other reasons,which will reduce the quality of the image and affect the accuracy of physician diagnosis.In order to reduce the metal artifacts in CT images,we address a method based on Mean Shift algorithm and interpolation image restoration algorithm in this paper,and the basic flow is as follows.Firstly,adaptive Mean Shift algorithm was used to smooth noise and the mild artifacts for preprocessing.Secondly,using Mean Shift simplified algorithm metal objects were segmented quickly and accurately.Thirdly,the prior image was generated by interpolated image with anatomical structures restoration,then the original projection data was replaced with the prior projection data to obtain the final corrected image.After the contrast experiment,the method in this paper not only removes metal artifacts remarkably but also protects the original anatomical structures,showing that our method achieves better appearance.关键词：metal artifact reduction;Mean Shift algorithm;interpolation;prior image;projection completion178|372|1更新时间：2025-07-16
- 摘要：This paper presents a low complexity non-binary LDPC decoding algorithm,whose complexity can be reduced in the following two ways.First,a new truncation scheme is presented to define the processing/non-processing check node subsets.The check nodes with relatively high reliability are not required to be processed,which can reduce the complexity.Second,for the check nodes in the processing subset,we further present a k-order message truncation for the states and branches of the check node Trellis.In the decoding iterations,only those "live" states/branches are involved in the message updating process,which can further reduce the computational loads at check nodes.Simulation results show that the presented algorithm performs very closely to several existing improved EMS decoding algorithms,but it has the lowest complexity when decoding the non-binary LDPC codes constructed both in low/high order fields.关键词：non-binary LDPC codes;trellis;node subset;message-truncation122|278|1更新时间：2025-07-16
- 摘要：Neighboring block disparity vector derivation in 3D High Efficiency Video Coding (3D-HEVC) is a key technology to get the disparity vector.To improve the quality of the disparity vector derived from the fast algorithm,we propose a proportion combination and group searching method to get the NBDV.We first changed the rule that takes the first search DV as final NBDV,and then divide the searching candidates into several groups for the proportion combination,after that design a strategy to search the candidates in several groups.The simulation results show that the proposed algorithm has improved the coding quality with negligible coding time loss.关键词：3D-HEVC;inter-view texture coding;neighboring block disparity vector;proportion combination;searching strategy2|2|1更新时间：2025-07-16
- 摘要：Aimed at that existing reasoning methods based on fuzzy Petri nets (FPN) and intuitionistic fuzzy Petri nets (IFPN) have the defects of complicated process and low efficiency in solving the problems only related to part of the knowledge base and they cannot analyze the causes of the problems,a hybrid reasoning method based on IFPN was presented.The method combined the forward reasoning and backward reasoning,firstly,the problems which needed to be solved were converted to goal places; secondly,in order to obtain potential causes of the problems and to simplify the reasoning model,associate places and transitions of goal places were searched by backward reasoning and a submodel was constructed; lastly,the problems of complicated process and low efficiency in using the original model to reason were solved by taking the submodel as the reasoning model and using forward reasoning to compute token values of goal places.Moreover,the real causes of the problems were found out by introducing threshold and the definition of route and active route into the model to remove the invalid associate places.The examples shows that the hybrid reasoning method is feasible and effective,and that compared with the existing methods shows that it overcomes the defects of the existing methods.关键词：intuitionistic fuzzy Petri nets (IFPN);forward reasoning;backward reasoning;hybrid reasoning2|2|1更新时间：2025-07-16
- 摘要：In order to label and trace the provenance of any simulated flow in multi-tenant network testbed,an interval-based flow watermarking and provenance tracing model was proposed.When a simulation flow was generated,this model first transformed the user's watermarking content into 0-1 bit sequence and then sent packets of the flow at particular intervals according to the 0-1 bit sequence to label the flow.When the simulation flow was captured by the model,the time intervals between packets in the flow were transformed into the 0-1 bit sequence so that the watermarking content could be extracted to trace the provenance of this simulation flow.The resilience against various known attack techniques is illustrated through theoretical analysis.Moreover,a large number of experiments prove the validity of this model in tracing simulation flows under both normal and abnormal circumstance.关键词：network testbed;cloud computing;watermarking;provenance tracing;simulated flow2|2|0更新时间：2025-07-16
- 摘要：The phase property is an important parameter of the intense relativistic klystron amplifier (RKA).But the intense relativistic electric beams (IREBs) with a long rise time in terms of high-power pulse power source will cause the output microwave phase jitter when driving the RKA,which limits the RKA's applications.Based on the intense current pulse electron beam properties,the impacts on output microwave phase by the increase of the electron beams' energy in the front section of the pulse and the spurious frequency caused by energy change in the cavities are analyzed through the theory.And then some PIC simulations and experiments are studied.It is found that the increase of the electron beams' energy in the front section lead to the output microwave phase continually changing.Besides,the spurious frequency in the cavity caused by the front section of the electron beams,which lead to the output microwave phase continually jitter in the front and the early of the stable section of the pulse.In the condition of cavities' parameters are constant,the output microwave phase is significantly affected by the rate of electron beams energy in the front section:when the rate of electron beams energy increase,the amplitude of the phase jitter and the jitter duration increase.And the stabilization of the phase can be increased by reducing the Q of the cavity at the frequency point of the spurious frequency.关键词：relativistic klystron amplifier;phase characteristic;forward voltage;high power microwave2|2|2更新时间：2025-07-16
- 摘要：In order to solve the problem of low power capacity and high insertion loss existing in varactor-tuned narrow filters,a tunable dielectric filter using piezoelectric transducers as tuning elements has been developed.The tuning of a dielectric resonator tuned by a piezoelectric transducer was analyzed,the control of coupling coefficient and external quality factor was discussed.The simulation results show that the coupling coefficient and external quality factor hardly varies with the tuning frequencies.A two-pole electrically tunable dielectric filter is designed and optimized by using HFSS software.The proposed filter was made of high Q-value dielectric resonators.Based on the results of ANSYS analysis,the effective measure of improving the tunability is suggested.The measured results show that center frequencies vary from 4.155GHz to 4.205GHz when bias voltages are applied from 0V to 50V with 3dB bandwidth of 37~40MHz.关键词：piezoelectric transducer;TE01 δmode dielectric resonator;dielectric filter;electrically tunable bandpass filter2|3|4更新时间：2025-07-16
- 摘要：Mutation testing is an effective fault-based testing method.However,the application of mutation testing in engineering development has been restricted by the high testing costs caused by a large number of redundant mutants.Regarding the mutants arising from the sequential statements in a program,an algorithm based on propagation-infection-execution (PIE) model was proposed,which employs the interval abstract domain to represent program state and the interval algorithm to evaluate the redundancy relation between the mutants.Meanwhile,regarding the conditional statements in a program,the redundant mutant selection algorithms based on the predicate fault hierarchy are also presented.The algorithms are designed for simple predicate and compound predicate respectively.By analyzing the effects of these algorithms,the constrained boundary condition for the development of non-redundant mutants under the condition of stratified sampling is concluded.Siemens Test Suite and other three open source projects are used to conduct experiments to compare the proposed method with random selection method.Experimental results show that the proposed method can reduce the mutant testing time cost while maintaining a high mutation score.关键词：mutation testing;mutation operators;redundant mutants;mutation cost;mutant reduction2|2|1更新时间：2025-07-16
- 摘要：SRAM-based FPGA (Field Programmable Gate Array) could be affected by SEU (Single Event Upset) in radiation environment,causing circuit function failures.This paper proposes an SEU-induced fault propagation model for FPGAs based on the graph theory and the cellular automata.In addition,this paper divides SEU effect into two parts:SBU (Single-Bit Upset) and MBU (Multi-Bit Upset) because MBU has an extra problem about conflict management.The core part of this model is the computing method of the coupling degree which is based upon relative bits from FPGA placement and routing results to make the model more accurate.After validation between fault propagation model and fault injection experiment,this fault propagation model is 19.89% more relative to fault injection experiment than the fault propagation model only counting relative bits in LUT (Look Up Table).Finally,this paper analyses an application about this model to find cells most easily leading to fault diffusion.关键词：field programmable gate array (FPGA);single event upset (SEU);single-bit upset (SBU);multi-bit upset (MBU);fault propagation model5|2|0更新时间：2025-07-16
- 摘要：Since the substrate integrated nonradiative dielectric(SINRD)waveguide fabricated directly on printed circuit boards(PCBs)was proposed,it has been a key issue how to excite the SINRD waveguide by using a planar structure.This paper presents a novel planar transition of the SINRD waveguide.The transition first uses a transition structure from microstrip to slotline.After that,since the field distribution of quasi-TEM mode of a slotline is similar to that of SINRD waveguide LSM11 mode,the main mode LSM11 of SINRD waveguide can be excited very well.By using multi-structure,two Arlon TC600 boards with different heights,the transition from microstrip to slotline can be directly fabricated on the thinner board.In this way,the good performance of the transition from microstrip to slotline can be achieved while the slotline is located almost in the middle of the dielectric strip of SINRD waveguide therefore can be used to excite the SINRD waveguide.It means that wider bandwidth and higher integration can be obtained.The simulation results and measurement data verify the novel transition.关键词：printed circuit board;slot line;substrate integrated nonradiative dielectric waveguide2|2|0更新时间：2025-07-16
- 摘要：The Stochastic Maximum Likelihood (SML) achieves exceptional performance of estimating Direction-of-Arrival (DOA).However,the high computational complexity of analytic method limits SML for further applications in practice.Considering the high computational complexity of SML,we propose a low complexity improved PSO algorithm,which outperforms the traditional PSO approach both in the number of particles and iterations.Based on the signals received by antenna,we firstly obtain the closed solution of Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) to pre-estimate the DOA.In addition,we compute the current Signal Noise Ratio (SNR) of the system as well as the SNR based Cramer-Rao Bound (CRB) of the SML.According to the pre-estimated DOA and current CRB,we then determine a small specific initialized space which is closed to the optimal solution of SML.Besides,we set a few particles in the corresponding search space.Finally,we construct the appropriate inertia factor which lead to an appropriate search speed for particles.Experimental results demonstrate that the number of particles and iteration times required by the improved PSO algorithm is about one-fifth of the traditional PSO algorithm,which greatly reduces the computational complexity of SML,the computation time is one-tenth of the traditional PSO algorithm,thus,the proposed method achieves significant merit of convergence speed.关键词：direction-of-arrival estimation;particle swarm optimization;stochastic maximum likelihood algorithm;computational complexity2|2|0更新时间：2025-07-16
- 摘要：Array transducer is the crucial component of all kinds of these instruments depending on ultrasonic phased array technology.While,efficiency changing and size error of a single element or several elements can make significant negative effects on the acoustic field and its directivity,and reduce the detection effect on the field of high performance and high resolution application.Using the adaptive algorithms,we presented a method to optimize and correct the array from the excitation mode of elements.By adjusting the excitation amplitude of each normal elements,the influence to the acoustic field from element failure can be decreased availably.The experiment results and theoretical analysis indicate that this method is much available to correct the acoustic field of the array with disabled elements by using the acoustic pressure of a few reference points in the field.In consequence,the array transducer with element failure or size errors can be well optimized by the method we proposed.关键词：ultrasonic phased arrays;element failure;directivity;distribution errors;adaptive algorithm2|2|1更新时间：2025-07-16
- 摘要：The order of the modulation used in existing adaptive demodulation schemes is no higher than 16,and the decoding of channel codes is not taken into consideration in the analysis and design.In this paper,an adaptive demodulation algorithm is studied.It includes multiple demodulation modes and can be applied to higher order quadrature amplitude modulations.A rate adaptive scheme at receiver is proposed which combines this algorithm and rateless error correcting codes.The bits whose absolute values of the log-likelihood ratio are the smallest in one symbol are deleted and the number of deleted bits varies in different demodulation modes,so the reliability and the average mutual information of demodulated bits can be boosted.From the perspective of mutual information analysis,the theoretical results of the required codeword length which meet the requirements of error performance are obtained.Moreover,the selection of the demodulation mode under a decoding complexity constraint is given.A sample scheme employing 256-QAM modulation constellations and Raptor codes is provided,and the simulation results of this sample are consistent well with those of the theoretical analysis,which confirms the effectiveness of the scheme.关键词：rateless error correcting codes;quadrature amplitude modulation;adaptive demodulate;rate adaptive;mutual information2|2|1更新时间：2025-07-16
- 摘要：The relationship between the number of non-zero singular values of the deterministic signal under the Hankel matrix and the number of frequencies in this signal is studied.It is found that if the dimension of matrix is larger than two times the number of frequencies,then no matter how much the dimension of matrix is increased,the number of non-zero singular values is always twice as much as the number of frequencies.The corresponding relationship between the non-zero singular values and single frequency component is studied,and singular value decomposition (SVD) is proposed to separate the single frequency component.The condition under which SVD separates the single frequency component is found,and SVD can accurately separate any single frequency component under this condition.This property of SVD is applied to the feature extraction of the bearing vibration signal,the time domain waveform of each vibration frequency is accurately extracted and the bearing vibration status is accurately revealed.关键词：singular value decomposition;non-zero singular value;signal decomposition;matrix dimension2|3|12更新时间：2025-07-16
- 摘要：The conflict between fast convergence rate and small steady-state misadjustment is a problem of the improved multiband-structured subband adaptive filter (IMSAF) algorithm with a fixed regularization factor.Based on the principle of minimizing the system noise,the power of the subband posteriori error is assumed to equal the power of the subband noise.Under this assumption a variable regularization matrix for the IMSAF algorithm is proposed to solve this problem.Simulation results show that the proposed method is superior to the IMSAF algorithm in terms of convergence rate,steady-state misadjustment and tracking capability.关键词：adaptive filtering;improved multiband-structured subband adaptive filter (IMSAF);variable regularization matrix3|2|1更新时间：2025-07-16
- 摘要：In order to analyze the non-linear and non-stationary spectrum occupancy time series which cannot be directly analyzed base on traditional time series method,a novel prediction modelling method of spectrum occupancy time series based on ensemble empirical mode decomposition (EEMD) and Artificial Neural Network (ANN) is proposed.Firstly,the spectrum occupancy time series is decomposed into serval intrinsic model function (IMF) so as to make every component stationary.Then in view of the stationary time series,a prediction ANN model is established correspondingly for each IMF.Simulative experiment for practical measured data shows that the proposed method has higher precision in comparison with other methods,i.e.,effective to non-linear and ono-stationary complicated spectrum occupancy time series prediction.关键词：electromagnetic environment;electromagnetic spectrum;spectrum occupancy;ensemble empirical mode decomposition (EEMD)2|2|1更新时间：2025-07-16
- 摘要：Future airspace window is a new method for fire shooting,and the aiming-points configuration for it is a key point to solve for practical shooting operation.To describe the ammo dispersion decided by aiming-points configuration,the intermediate function is adopted.A function approximation method with derivative-free optimization is used to optimize the configuration parameters,with the distance norm of the intermediate function and that of the optimal intermediate function set as an index,so that the kill probability under the given configuration can approximate its upper bound.With mesh configuration and circular configuration as examples,the proposed approximation method and an analytical method are respectively applied to solve the aiming-points configuration parameters,as well as the kill probability,in different relative errors.The results show the advantages of the approximation method in more approaching the upper bound of kill probability and more universal in applications.关键词：future airspace window;aiming-points configuration;function approximation;derivative-free method2|2|3更新时间：2025-07-16
- 摘要：The electromagnetic radiation of computer contains video information which causes the information leakage.In this paper,a method is proposed according to the effect of human visual,based on the random scrambling,which called complementary scrambling,for preventing the leakage of video information through the electromagnetic radiation.The effect of human visual can eliminate the interference of noise to video image by adding and subtracting the random noise to each contiguous frame of video information,and imposes noise on displayed screen images while keeping the quality of the image.And realize the function of preventing the video information electromagnetic leakage.Finally,the feasibility of the method is verified by experiments.关键词：video information;electromagnetic leakage;information security;complementary scrambling3|3|2更新时间：2025-07-16
- 摘要：Quantum-dot cellular automata (QCA) is an emerging nano-device that can be considered as a promising alternative for semiconductor transistor.An improved dual-edge triggered structure and JK flip-flop are proposed.The reliability of the dual-edge triggered structure is higher than that of previous designs through the probabilistic transfer matrix.Furthermore,compared to the previous designs of JK flip-flop,the dual-edge triggered JK flip-flop based on the vertically-stacked block has less cell number and smaller area.关键词：quantum-dot cellular automata;JK flip-flop;dual-edge triggered structure;probabilistic transfer matrix2|3|1更新时间：2025-07-16
- 摘要：This paper investigates the problem of optimal data collection strategies for wireless sensor networks (WSNs) with limited resources.First,a sensor node periodically collects data and utilizes the Kalman filter (KF) to filter noise.Then,considering that communication is a primary source of energy consumption,we develop data transmission strategies to decide at which times the sensors should transmit their data.The proposed strategies can maximize the accuracy of data gathered by the base station for a required network lifetime.To be more specific,for single-hop networks,the optimal data transmission strategy is obtained which can minimize the estimation error.Based on this single-hop optimal strategy,the modified data transmission strategy is proposed for multi-hop networks.Simulation and prototype experiment results show the effectiveness of the presented strategies.关键词：Wireless sensor networks;data collection;energy efficiency;data accuracy;Kalman filtering2|3|1更新时间：2025-07-16
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