最新刊期
卷 42 ， 期 2 ， 2014
- 摘要：Keyword Search over Relational Databases (KSORD),a more straightforward and user-friendly way of retriving data in relational databases,has raised much attention and been widely studied in recent years.However,there are still some problems in the existing techniques.To solve these problems,Extractor,a new KSORD system based on datagraph,is proposed in this paper.The datagraph used by Extractor is derived from exiting datagraphs,which has been improved a lot and the new features are the bases of the new generating and ranking mechanism of result trees used in Extracor.The interactive query-reformulation method based on word co-occurence is also embedded in Extractor to help users find the right query.Experiments verify the effectiveness and efficiency of Extractor.关键词：keyword search;relational database;query reformulation;top-k query2|1400|2更新时间：2025-07-16
- 摘要：A novel method for self-adaptive dual-channel pulse coupled neural networks (DC-PCNN) based on PSO evolutionary learning is proposed in order to overcome the difficulty of parameters selection of DC-PCNN.In this study an evolutionary learning algorithm and a new optimization criterion are proposed to optimize the parameters of PCNN for image fusion.In contrast with classical DC-PCNN method that needs to try different parameters settings manually,the proposed method can find the optimal parameters adaptively.Experimental results obtained on benchmark databases verify the above advantages.关键词：dual-channel PCNN;evolutionary learning;multi-criteria objective function;image fusion2|2688|11更新时间：2025-07-16
- 摘要：Many T-wave alternans (TWA) detecting algorithms have been proposed in the past,but most of them cannot provide an accurate and robust result,especially for non-stationary,non-linear and non-gaussian TWA in dynamic ECG.In this paper,a non-linear state space model with Laplace noise is proposed first,then particle filters is applied to estimate and analyze the T-wave alternans (TWA) amplitude in dynamic ECG.Simulated ECG signal with different TWA amplitudes and twadb database with clinical ECG records are evaluated by our proposed method.From the simulation results,our proposed algorithm is demonstrated the most accurate and robust for TWA detection when adding gaussian noise and non-gaussian noise,comparing to conventional spectral method (SM) and modified moving average (MMA) method.Besides,non-stationary TWA can be tracked accuratly in real-time by the proposed method.关键词：electrocardiogram (ECG);T-wave alternans (TWA);particle filter;laplacian noise2|1917|2更新时间：2025-07-16
- 摘要：By introducing opposition-based learning (OBL) in PSO,particles are enabled to find an opposite position that is closer to the global optimization solution.However,OBL only makes a good performance on the initial phrase of the evolution,while at later stages it needs to be combined with other techniques (e.g.Cauchy mutation) to improve its ability of "exploration".In this paper,a novel OBL based on the principle of lens imaging is proposed.It uses two parameters (i.e.,zoom factor and the factor of search radius),which will achieve a better balance between PSO's "exploration" and "exploitation" abilities.The simulation shows that the novel OBL possesses better convergence rate and convergence effect.关键词：opposite-based learning;particle swarm optimization;imaging lenses2|2207|26更新时间：2025-07-16
- 摘要：The transport of intensity equation is solved to recover the phase information through the combination of optics and calculation in the method of phase retrieval based on the intensity measurement.This method is proved to be a feasible way to obtain phase information theoretically and experimentally.A new derivation of Green function method in Neumann and Dirichlet boundary conditions is deduced.Because the partial derivative of Green's function is a four-dimensional matrix,large memory space will be occupied with the improvement of image resolution by solving the function directly.The numerical processing method is presented and extended to natural light conditions.At same time,an optical data collection platform is built.Simulation and actual experimental results verify this new phase retrieval method is reasonable and correct.关键词：phase retrieval;Green function;transport of intensity equation;Neumann boundary;Dirichlet boundary2|1393|1更新时间：2025-07-16
- 摘要：Because of the distortions produced by the reflection of a mirror,catadioptric omnidirectional images cannot be processed similarly to classical perspective images.In this paper,we propose to define a new model named omnidirectional total variation (Omni-TV),which reflects the omnidirectional image structure features.In order to reconstruct the images from compressive samples,the Omni-TV is used as the subject function during the image reconstruction.The simulation results show that the omnidirectional images could be reconstructed effectively and accurately.Comparing with classical TV minimization model,the images,which are recovered based on Omni-TV model,can provide higher quality both in subjective evaluation and objective evaluation.关键词：catadioptric omnidirectional imaging;compressed sensing;image reconstruction;TV norm2|2550|4更新时间：2025-07-16
- 摘要：Facing the sparse LiDAR (Light Detecting and Ranging) data of New Orleans area in America,a new residential building reconstruction method based on the fusion of LiDAR and satellite imagery is proposed.The main contribution of this work is the automatic isolation of roof points and roof type recognition.Using LiDAR data boundary to identify the ROI area in satellite imagery,and using cue lines extracted from ROI areas,the building roofs are isolated.Then,based on the relationship of normal vectors,building types are recognized,and then buildings are reconstructed.Experiments show that our method can successfully reconstruct residential buildings given relatively sparse LiDAR samples,achieve a high reconstruction rate in a reasonably short time,which meet the requirement of virtual reality systems.关键词：building reconstruction;data fusion;cue lines;liDAR;roof isolation2|2035|2更新时间：2025-07-16
- 摘要：In order to make better use of information for edge detection of color image,an approach of color image edge detection which combines Gauss Manhattan distance map into RGB space is proposed in this paper.Firstly,the loss of information generated from color image to gray image conversion is analysised and a method of RGB space edge measurement is raised.Then,a new unified distance map is got from separately Gauss Manhattan distance map of color image by the measurement in three channels of RGB.Finally,a new unified distance map is mapped to range of 0~255,and the result of edge detection is obtained.Experimental results show the approach proposed in this paper has higher processing speed and better treatment effect.关键词：Manhattan distance;edge detection;RGB space;distance map5|2463|10更新时间：2025-07-16
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A Method Based on the GNC and Augmented Lagrangian Duality for Nonconvex Nonsmooth Image Restoration
摘要：The graduated nonconvex method(GNC) and augmented Lagrangian duality have superior restoration performance for nonconvex nonsmooth image restoration.However,the global convergence of the general GNC could not be guaranteed and an effective initial value could not be obtained for the augmented Lagrangian duality when they are used separately.To overcome these drawbacks,we propose a hybrid method based on the GNC and augmented Lagrangian duality by transforming the original problem into equality constrained optimization,then its dual convergence has been strictly proven.The proposed method could get an effective initial value and does not require the convexity and smoothness of the underlying problem.Moreover,an adaptive energy function is generated by the dual iterations.Experimental results show that the proposed method could enhance the quality of restored images and the efficiency of algorithm effectively.关键词：nonconvex nonsmooth;potential function;augmented Lagrangian duality;graduated nonconvex method(GNC);image restoration4|1622|2更新时间：2025-07-16 - 摘要：Currently,most of the color demosaicking algorithms using only a local spatial and spectral correlation,easily lead restored picture to blur edges and loss of fine structures.When cyclical small structures exist in the image,these local methods are prone to the distortion of the zipper effect,the raster effect,etc.To solve these problems,unifying dictionary learning and sparse coding into a variational framework,a non-local adaptive sparse representation model is proposed through non-local similarity clustering and adaptive dictionary online learning.Using the local and non-local redundancy,sparse coding constraints forced sparse coding close to its non-local means to reduce coding errors.Moreover,the fidelity term is characterized by l1-norm to suppress the heavy-tailed visual artifacts.Finally,the joint alternating minimization method and operator splitting techniques are utilized to effectively solve the model.Experimental results demonstrate the effectiveness of the proposed model and the numerical algorithm.关键词：color demosaicking;regularization;sparse representation;nonlocal similarity3|2362|4更新时间：2025-07-16
- 摘要：The fractional wavelet transform extend the analysis method of wavelet transform about time-frequency domain to time-fractional frequency domain,can characterize signal features in time and fractional-frequency domain.Based on the theory of multiresolution analysis(MRA) of the fractional wavelet,the new forms about coefficient decomposition and reconstruction of discrete fractional wavelet transform(DFRWT) are given and made two-dimensional expansion.According to the feature of subband coefficient energy of image based on DFRWT varies with different p order,a novel image threshold denoising method based on DFRWT is proposed.The method in conditions of keeping the energy of low frequency subband for absolute great value,appropriate to raise the distribution of energy percentage,more beneficial for image noise suppression.The experimental results show that the performance of this method is better than the traditional wavelet threshold denoising method both in vision effect and peak signal to noise ratio.关键词：fractional wavelet transform;wavelet transform;multiresolution analysis;image denoising2|2295|9更新时间：2025-07-16
- 摘要：An image data query algorithm based on latent semantic indexing in domain ontology and singular value decomposition is proposed.It projects query expansion vector on latent semantic area.A new method to computing similarity between query vectors and query documents is proposed.Users can get accurate and effective retrieval results using the similarity.The experimental results show that the proposed solution can improve image index query recall ratio and precision ratio.关键词：image index query;ontology;latent semantic indexing;singular value decomposition2|2108|2更新时间：2025-07-16
- 摘要：A fundamental problem in XML data handling is hierarchical data sorting.This paper focuses on this problem and proposes an effective sorting algorithm called XPSort for XML document.XPSort exploits multi-core CPU to parallelize the executions of the mutually independent tasks generated by scanning the XML document;and effectively reduces disk I/Os through data compression,single temporary-file storage and avoidance of tree-matching.XPSort overcomes the issues of inefficient space utilization,large number of random I/Os and inability to handle right-deep tree in NEXSORT,and avoids data redundancy and large disk I/O costs in HERMES.Extensive experiments on XML documents with different characteristics show that XPSort outperforms other existing sorting algorithms.关键词：XML document;hierarchical data;sorting algorithm;parallel algorithm2|1424|1更新时间：2025-07-16
- 摘要：Along with the ever-growing Web,horror videos sharing in the Internet has threatened children's psychological health.It is necessary to effectively recognize and filter out these horror videos.So far,several horror video recognition methods based on Multi-Instance Learning (MIL) have been proposed.However,all these methods suppose that the instances in a bag are independent,ignoring the contextual cue and statistical cue in horror videos.In this paper,we propose a novel multi-view joint sparse coding model for horror video recognition.This model considers video from three different viewpoints including set view,contextual view and statistical view.The set view treats a video as a set of independent frames.The context view models the contextual relationship among key frames in a video using an e-graph.The statistical view represents a video as a histogram feature based on bag-of-words model.Then,three kernel functions are designed for the three viewpoints,respectively.Finally,the three kernels are integrated into a unified multi-view joint sparse coding classification framework to recognize the horror video scenes based on reconstruction residual.Experiments on a horror video dataset demonstrate that our method's performance is superior to the other existing algorithms.关键词：horror video;sparse coding;multi-view;kernel2|1734|4更新时间：2025-07-16
- 摘要：This paper proposes an approach to analyze the temporal and spatial correlations between objective activities from multiple non-overlapping camera network.Based on the similarity of moving models and the relationship of moving space,each vision field of camera network is segmented into semantic active regions automatically.Then a Cross Kernel Canonical Correlation Analysis is implemented to explore the correlations between these active regions and the topology of the camera network.This topology can reflect the temporal and spatial information of objectives cross multi-cameras and improve the accuracy of objects re-identification by removing false objects.Compared with existing methods,our approach does not depend on the individual tracking and is efficient in complex and crowed scene.The experiment results show that our approach performs effectively and efficiently in multi camera surveillance network.关键词：camera view decomposition;KCCA;multiple camera content understanding2|1484|5更新时间：2025-07-16
- 摘要：For video plus depth based mobile 3D video streaming,this paper proposes a cross-layer optimized rate adaptation and error control method.The proposed method tunes the coding rate and intra refresh coding ratio at the application layer,and modulation and channel coding scheme at the physical layer by minimizing the end-to-end 3D video distortion.Thus,the proposed method can reach the goal of adapting source rate to the channelbandwidth as well as leveraging the error control strengths between the application layer and physical layer.Correspondingly,the virtual view quality of the 3D video at the receiver can be improved.Experimental results show that the proposed method can efficiently improve the 3D video streaming performance.关键词：mobile 3D video streaming;cross-layer rate adaptation;error control2|1573|0更新时间：2025-07-16
- 摘要：A novel neural network model named fuzzy lattice constructive morphological neural network (FL-CMNN) is presented to overcome the deficiency of the original constructive morphological neural network(CMNN),which suffers for the problem of decision function in classification phase.The fuzzy lattice inclusion measure function is introduced to calculate the membership of testing sample belong to the hyper-boxes trained by the CMNN.Three standard datasets are employed to evaluate and compare the presented FL-CMNN with the CMNN,artificial neural network(ANN),support vector machine(SVM)and K nearest neighbor(KNN)classifiers.Experimental results have revealed that the presented FL-CMNN yields better performance than the original CMNN model.It also achieved comparative classification accuracies with much lower computational cost than traditional ANN and SVM model.关键词：mathematical morphology;morphological neural network (MNN);fuzzy lattice;pattern recognition2|1303|2更新时间：2025-07-16
- 摘要：Using optimization algorithm to solve the node localization problem has become a research focus.This paper makes deep analysis on the distance relationship between two successive localization results and designs a neighborhood function,and then proposes the greedy localization algorithm based on greedy idea.The proposed algorithm is divided into two phases.In the first phase,a set of estimated positions is generated based on the greedy iterative optimization.In the second phase,some unknown nodes will be elevated to anchor nodes,and the first phase is executed again.The second phase is repeated until there is no node that can be elevated to an anchor node.Finally,the experimental results show the proposed algorithm achieves more accurate result and take less time than the existing optimization localization algorithms.关键词：node localization;optimization algorithm;neighborhood function;greedy idea;iterative optimization4|1359|4更新时间：2025-07-16
- 摘要：To conquer the problem of lack of direct torque in the under-actuated systems such as single wheel robots missiles satellites and spacecrafts,a device of torque generation is proposed in this paper.The research results are acquired under the theory of classic electromagnetism,and the details of the mechanism of the device are explained.The torque provided by the proposed mechanism is proportion to the speed,so it is rather convenient to perform exact control by motors.The experiments carried out on single wheel robot's lateral and yaw control respectively are included to demonstrate the superior performance the proposed method over some traditional ones,which illuminating the promising practical application potentiality of under-actuated systems.关键词：under-actuated;torque;electromagnetic effect;single wheel robot2|1208|0更新时间：2025-07-16
- 摘要：Integrate circuits(ICs) may be inserted malicious circuits as a hardware Trojan during fabrication.A novel hardware Trojans non-destructive detection technique using the electromagnetic side channel signals of chips is proposed.The technique includes two steps.Firstly,the surface of chip is divided into smaller sub-blocks,and a suitable input vector set is generated with a special selection algorithm.Secondly,based on the projection pursuit with negative entropy index,the detector could find out the data structure enables reflect high dimension special rules without obvious information loss,so as to attain the goal of feature abstraction and identification on side channel signals of IC chips.The detection experiments against an exemplary AES-128 hardware Trojan circuit showed that the technique proposed in this paper could distinguish the difference of side channel signal's feature between the genuine chip and tested chip,and consequently could detect the existence of the hardware Trojan.关键词：integrate circuit(IC);hardware Trojans;electromagnetic analysis;projection pursuit;Trojans detection5|1650|9更新时间：2025-07-16
- 摘要：The resolution precision and algorithm stability of the short-time fractional Fourier transform (STFRFT) time-frequency method was studied.Firstly,the mathematical expression of the STFRFT time-frequency resolution was given in this paper,which is beneficial to the time-frequency resolution theory quantitative comparison,and simulation results showed that the theoretical quantitative value is basically consistent with the observed value.Secondly,this paper proposed a fast calculation method of STFRFT to decrease the computational complexity,its calculation amount comparing with the traditional search method was reduced about an order of magnitude;Finally,the paper gave the estimation error theoretical analysis of the algorithm and applied the method to analyze the multi-target signal.The simulation results showed that this method could effectively suppress cross-terms and resolve the problem of multi-component signal separation.关键词：short-time fractional fourier transform(STFRFT);time-frequency transform;order estimation;multi-component signal separation2|2943|19更新时间：2025-07-16
- 摘要：There could be large error in Compressive Sensing Ultra-Wide Band (CS-UWB) channel estimation because of the coherence of sensing information matrix and the noise interference.Firstly,the Adaptive Sensing Information (ASI) matrix is constructed by measurement vector weighting,which has the desirable properties of low coherence and containing measurement information to support the sparse recovery algorithms to obtain optimal atoms.Secondly,a modified Sparsity Adaptive Matching Pursuit (SAMP) algorithm is proposed to recovery sparse signal accurately without prior information of sparsity or SNR.Finally,a non-convex CS-UWB channel estimation method is presented based on the ASI matrix and the modified SAMP algorithm.Both the theoretical analysis and the experimental results show that this method can accurately reconstruct UWB communication channel in low SNR conditions with very low compressive sampling ratio.关键词：compressive sensing;ultra-wide band communication;sparse channel estimation;adaptive sensing information operator;modified SAMP algorithm2|1725|9更新时间：2025-07-16
- 摘要：Blind source separation (BSS) for convolutive mixtures can be solved efficiently in the frequency domain,however,the permutation problem must be solved in the frequency domain BSS.This paper studies the influence of distance between frequency bins and separation quality at each frequency on permutation algorithm based on the amplitude correlation between neighbor bins,and proposes an improved method for permutation.The influence factor is utilized to control the influence of separation quality and distance between frequency bins on permutation.Lager influence factor is set for frequency bins of short distance and good separation quality;otherwise a smaller factor is set.Functions for setting influence factor are discussed in detail in this paper.Experiments of BSS for instantaneous mixtures,convolutive mixtures and real-room recorded data are made at last.The results demonstrate the performance of the proposed algorithm is good.关键词：blind source separation;signal processing;permutation;amplitude correlation;influence factor2|1962|1更新时间：2025-07-16
- 摘要：In order to protect the confidentiality and privacy security of the composite documents within the whole life cycle,we leverage attribute-based encryption (ABE) algorithm to propose a secure self-destruction scheme for composite documents,referred to as SelfDoc.We firstly set up a new composite document structure by employing the idea of multilevel security,and then,use an access key to encrypt the composite document and the ABE algorithm to encrypt the access key.After a series of algorithms for extracting and transforming from the two ciphertexts,we obtain ciphertext shares and encapsulated self-destruction object,both of which are stored into two distributed hash table (DHT) networks and cloud servers respectively.Nodes in the DHT networks will self-discard the ciphertext shares periodically,so the original ciphertext and access key are unrecoverable after the expiration time,and the function of secure self-destruction is achieved.Compared with existing schemes,the security analyses indicate that SelfDoc scheme is able to resist the traditional cryptoanalysis or brute-force attack,and the Sybil attacks from the DHT networks.关键词：composite document;privacy security;attribute-based encryption;secure self-destruction;DHT network2|2176|7更新时间：2025-07-16
- 摘要：In order to further improve the identification efficiency of the Radio frequency identification (RFID) system,an efficient anti-collision protocol based on on-demand slot assignment is proposed.In this protocol,each identification round is divided into two steps including reservation stage and identification stage.The proposed protocol avoids collision frame slots and empty frame slots by the capture mechanism of reservation collisions and by the reservation mechanism of frame slots,respectively.Furthermore,the optimal bit number of reservation random code and the optimal number of reservation slots are given for obtaining the optimal efficiency.The paper analyses the circuit complexity of tag based on the protocol,and proposes the tag estimation method suitable for the protocol.Performance estimation shows that the average efficiency of the protocol is about 91.28% and it significantly outperforms the existing anti-collision protocols in terms of communication complexity and identification speed.关键词：radio frequency identification(RFID);anti-collision;reservation;capture;tag estimation2|1547|3更新时间：2025-07-16
- 摘要：The research work of hardness on evolutionary algorithm is an important branch of evolutionary computation.It aims to study the relationship between the performance of evolutionary algorithm and the characters of the optimization problem.And,the goal of the hardness research is estimating the performance of an evolutionary algorithm deployed in one optimization problem by using limited information.This paper summarizes six kinds of hardness theories on evolutionary algorithm,such as fitness-distance correlation model,fitness landscape methods,landscape state machine,optimal contraction theorem,epistasis methods,etc.and eight hardness indicators with them.Furthermore,this paper discusses the advantages and disadvantages of these methods,and prospects the trends of this research field.关键词：fitness landscape;spatial correlation;landscape state machine;epistasis measure;optimal contraction theorem;optimization hardness2|1593|4更新时间：2025-07-16
- 摘要：Choosing coastline as landmark is an important automatic image-based method for satellite navigation.The method selects a specific area in the remote sensing image,detects the coastline in it,and matches it with the corresponding region of the standard global coastline template library.The calculated offset determines how to adjust the posture of the satellite.Considering the characteristics of the automatic image navigation process,we propose a method to detect land and sea boundary in infrared channel of remote sensing images.The method,which is based on level set,is initialized by the standard template library and is equipped with region-scalable fitting energy model.The experimental results indicate that our algorithm has advantages in efficiency,stability and accuracy.关键词：edge detection;level set;image processing2|1308|6更新时间：2025-07-16
- 摘要：In breast-CAD system,the segmentation of breast mass is an important step for pretreatment.In this work,the Gmac model is applied for breast mass segmentation,meanwhile,two improved methods to solve the Gamc model are proposed:the improved Level-set algorithm and the improved split-bregman algorithm.In experiment part,we select 483 medical images for test.The CM for the two algorithms is 64% and 76% and AMED is 4.4750 and 1.4602 respectively.The experimental results show the improved split bregman method is more effective for breast-mass segmentation.Besides,the ACWE model and GAC model are used for comparison and the results indicate that the Gmac model is more suitable for breast-mass segmentation.关键词：breast lumps segmentation;global optimal active contour model;split bregman method4|1669|1更新时间：2025-07-16
- 摘要：Integral circuit is the key element to restore the signal in the current-based electronic voltage transformer(EVT),and its performance directly affects the steady and the transient characteristics of the EVT.An integral circuit with DC-isolating control used in the current-based EVT was proposed.It can effectively block the DC component of the input signal,resulting in the improvement of the transient performance of the EVT.And its frequency width can assure below 40th harmonic voltage measurement.The method of using the thermal resistor to compensate the temperature characteristic of the integral circuit was also proposed,which can improve the stability of the EVT.An EVT prototype based on the designed integral circuit was developed and then tested.The analysis and then experimental results demonstrated the practicability and the validity of the proposed integral circuit.关键词：electronic voltage transformer;integral circuit;signal restore;temperature compensation;transient performance2|1934|1更新时间：2025-07-16
- 摘要：Thermal annealing is widely used to promote copper grain growth and reduce electrical resistance of the through-mask plated redistribution layer in wafer level package.However,the crack on the surface of the sputtered copper seed layer prevents the plating process in the crack and increases the electrical resistance,and results in void formation on the interface between the sputtered seed layer and the plated copper interconnects.To solve this problem,the sputtered seed layer was slightly etched before the electroplating process and a TaN layer was sputtered on the Cu interconnect surface before thermal annealing process.The process suppressed void formation during the electroplating process and the annealing process at 300℃.This process resulted in grain growth at elevated temperature and lower electrical resistance in the copper interconnects.关键词：through-mask plating;void;thermal annealing2|2498|0更新时间：2025-07-16
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