最新刊期
卷 37 ， 期 8 ， 2009
- 摘要：Constructing the phylogenetic tree of life is an important resort of learning the origin and the evolution among species.By introducing the concept of "kernel",a method to achieve phylogenetic tree based on KEGG metabolic pathway is presented.We firstly solved the problem of pathway abstraction with no metabolic information lost,and secondly we defined the similarity between different metabolic pathways as the summation of weighted matching score of the kernel subgraph and the non-kernel one respectively.Based on the distance matrix obtained by the two steps above,we construct the phylogenetic tree of several species.The experiments show that it is an efficient method according to the comparison between the trees obtained and NCBI taxonomy.关键词：phylogenetic tree;metabolic pathway;kernel-based method;pathway alignment2|1048|3更新时间：2025-07-16
- 摘要：The existing works only consider how to efficiently process skyline computation for a single table.That is,they assume the issued skyline queries do not involve any traditional relational operator.Clearly,in most real applications,the query efficiency is extremely low because of this unreasonable assumption.Motivated by these facts,we regard skyline computation as a special relational operator and study the equivalence transformation rules of implementation order of it and traditional relational operators.Then based on these equivalence transformation rules,we can efficiently improve the query performance.Moreover,we present sufficient theoretical proofs to demonstrate the correctness of the proposed equivalence transformation rules.The extensive experiments also show that the after-transforming solutions markedly outperform the before-transforming counterparts.关键词：database;skyline query;relational operator;equivalence transformation rules;query optimization2|854|0更新时间：2025-07-16
- 摘要：Ant Colony Optimization is a novel simulated evolutionary algorithm which has been used successfully to solve many complicated combinatorial optimization problems,but its convergence analysis is seldom researched.The mathematical model of a class of ant colony algorithms is described by TSP problem.On the basis of the decomposition of state space and the construction of reflecting barrier,an almost everywhere strong convergence of the algorithms and the quality that the algorithms can guaranteedly converge to a global optimum set in a finite number of steps are demonstrated by using the martingale theory,and the obtained results may provide a new methodology for convergence analysis of the algorithms.关键词：ant colony optimization;Markov process;martingale;almost everywhere strong convergence2|1075|14更新时间：2025-07-16
- 摘要：The drops of the cloud spread around while the hyper entropy (He) is increasing.But many drops still stand in the central area of the cloud.Atomized feature of the cloud model can be used to adjust the strategies of the evolution.In cloud based evolutionary algorithm,changing He to affect the selection pressure and lead to different evolution result.By the experiments of nine typical test functions’ optimization,the precision,stability and convergence rate of the algorithm are well proved.关键词：genetic algorithm;cloud model;evolution strategies;atomized feature2|1416|42更新时间：2025-07-16
- 摘要：The monitor task of the same scene was assigned to three highly-correlated video sensor nodes based on YUV color space and the view correlation of adjacent nodes.Each sensor node only needed to take charge of compressing and transmitting luminance or chrominance part.With the proposed depth information model,luminance and chrominance parts were fused using fusion method based on adaptive quadtree partitioning and space transform.And then the color image of the scene was reconstructed.The experimental and simulation results show that our method is effective and feasible.A well tradeoff is achieved between store,transmission cost and scene monitoring quality.关键词：wireless multimedia sensor networks;color space;image fusion;quadtree partitioning2|669|1更新时间：2025-07-16
- 摘要：To solve the missed diagnosis of small pulmonary nodules in medical images,a new approach on computer-aided diagnosis for lung cancer based on chest CT images has been proposed.The method firstly segments the Region of Interest(ROI),and extracts ROI’s features.Then it selects effective attributes by theory of Rough Set(RS).Finally,it constructs a specific-demand oriented recognition model for lung cancer based on these effective features.Especially,we take the Self-Organizing Neural Network(SONN)to construct the recognition model of lung cancer for fast diagnosis.In order to perform the accurate diagnosis,we need to use the Self-Adaptive Probabilistic Model(SAPM)to build lung cancer and non-cancer recognition models respectively and we can identify the classification by the similarity of the recognition sample with the model.When the similarity is small,we re-identify the lung cancer by Hidden Markov Model(HMM).The experiment results proved that the approach mentioned in this paper can hold high efficiency.关键词：lung cancer;computer-aided diagnosis(CAD);self-adaptive probabilistic model(SAPM);hidden Markov model(HMM)2|972|3更新时间：2025-07-16
- 摘要：This paper gives a formal analysis method of mobile agent data integrity protocol.We pointed out that authentication property is not suit to analysis mobile agent data integrity,and proposed two formal specifications for mobile agent data integrity.We constructed a CSP model for a concrete mobile agent data integrity protocol,checked its integrity using rank function.These works prove formal analysis method is effective in analyzing mobile agent data integrity protocol.2|993|0更新时间：2025-07-16
- 摘要：Due to the decoding dependency of MPEG coded frames,now existing methods on VCR implementation have to face the problem of how to settle the transmission of extra frames caused by this decoding dependency which would brought in heavy resource consumption and high STB decoding complexity. To tackle the problem,based on GOP (Group-of-Pictures) fetching and variable frame rate (VFR),our VCRimplementation method called G-VFR is proposed. GOP based frame-fetching can effectively eliminate the dependency transmission,and VFR leads to optional transmission rate. The experimentation results demonstrate that G-VFR can reduce the transmission rate of fast-scan operations to 22% of that of normal playback,and the VFR character can be achieved by parameter adjusting,meanwhile G-VFR can be used in real-time streaming system such as Time-Shifted TV.关键词：VCR (Video cassette recording);GOP (Group of Pictures);variable frame rate;STB (Set-Top Box);MPEG video;streaming media2|947|2更新时间：2025-07-16
- 摘要：Plane target coverage problem is one of sensor networks’ fundamental problem for targets coverage.We proposed the coverage analyses methods for plane target in sensor networks based on Clifford algebra.The plane target was described with Clifford algebra.And the computational methods of coverage rate for plane target were also mentioned in sensor networks.We also proposed the algorithm for calculating the maximal breach path of plane target in sensor networks and the experiment proved the efficiency of our method.关键词：sensor networks;clifford algebra;coverage;plane target;maximal breach path2|1051|0更新时间：2025-07-16
- 摘要：The configuration of a novel spatial power combiner in waveguide was introduced.Employing the optimized Klopfenstein tapered fin line arrays,the waveguide-based power combiner based on 2×3 arrays at C band was realized.Its size is 70.12mm×98.44mm×160mm and it was implemented by using six commercial GaAs MMIC amplifiers.CW power combiner measurements were performed,the linear gain is about 8.5dB,the saturation output power is 42.82dBm(19.1W)at 4.2GHz ,the PAE is 25.3％ and the efficiency is about 72.3％.关键词：spatial power combiners;klopfenstein taped fin line arrays;MMIC PA4|1125|1更新时间：2025-07-16
- 摘要：The mode competition and amplitude instability of Relativistic Extended Interaction Cavity Oscillator encountered with in the initial experiment were investigated in this paper.The modulation mode-competition was overcome by adjusting the modulation cavity gap width.The pulse repetition rates increasing from 15Hz to 100Hz and the output microwave pulse width increasing from 20ns to 38ns were improved after optimizing the structures of the electron beams collection and the triaxial output cavity.Using a 900kV,16kA,45ns electron beam,4.1GW radiated power was extracted in 38ns FWHM pulses at 2.85GHz and 100pps.The power efficiency is 26%,and the energy efficiency is 22%. The radiated average power is 16kW.关键词：extended interaction cavity;oscillator;triaxial output cavity;high power microwave;repetitively operation2|850|4更新时间：2025-07-16
- 摘要：In this paper,based on an analysis of the effects of static phase errors on delay-locked loop (DLL),a novel high-resolution phase detector (PD) in use for a 30-phase 500MHz DLL,is proposed.It incorporates the feature of the Hogge PD with the feature of the Alexander PD.Compared with conventional linear and binary PDs,the proposed PD not only has advantages of a perfect linear PD,but also solves the problem of dead zone in course of charge pump’s switch transition,which exists in linear PDs,and eliminates static phase errors caused by current mismatch in the charge pump.Furthermore,the layout of the proposed PD in a 1.2-V 0.13μm CMOS process is implemented.Finally,the HSPICE post-layout simulation is performed.The simulation results show that the proposed PD can detect the delay difference between two phases no less than 1ps,and achieve the resolution of 0.18 degree.关键词：phase detector;delay-locked loop;static phase error;clock phase;clock jitter.2|1707|4更新时间：2025-07-16
- 摘要：Based on the characteristics and needs of collaboration for multi-users in Collaborative Virtual Environment (CVE),this paper proposed a dynamic admission control mechanism based on QoS.It updated system minimum delay dynamically.When users tried to access the system,it compared the QoS of users’ subscription and system minimum delay to determine whether they can access or just hung up.The experiment shows that the dynamic admission control mechanism can make network flow stable and reduce router process load,and let users get the system information at real time to adjust their local processes.关键词：collaborative virtual environment;QoS (Quality of Service);dynamic admission control;minimum delay2|758|0更新时间：2025-07-16
- 摘要：Base on working principium of optocoupler,and the theory of radiation and 1/f noise,The mechanism and the charactory of radiation optocoupler are analysed,1/f noise radiation model are established.flowing tatal dose ,Flowing the radiation dose increasing,traps of LED and phototransistor increasing,fluctuate of carries growing,the power spectrum of voltage noise largening,the power spectrum of voltage noise may be a new denotable parameter for optocoupler reliability.关键词：optocoupler;radiation;noise2|993|3更新时间：2025-07-16
- 摘要：A Power Amplifier (PA) fingerprinting method based on the Volterra series model is proposed for specific emitter identification of wide band emitters.To cover the adaptability and dimension explosion shortcoming of the traditional Volterra identification method,a new MIMO model is derived for the code modulation signal and the linear/nonlinear frequency modulation signal.And the distance of the subspace is adopted to compare different Volterra systems.The independent and measurable properties of the method are given,and the principle of the method is verified by the simulation experiments.关键词：electrical war;emitter identification;specific emitter identification;power amplifier;Volterra series model2|1031|0更新时间：2025-07-16
- 摘要：On the basis of the bulb physiological anatomic structure,a comparatively integrated bulb neural electrophysiological model incorporating periglomerular cells (PG),mitral cells (MC) and granule cells (GC) is constructed here originally by means of their ion channels and neurotransmitters among the dendrodendritic synapses in the neural cell network.This model preliminarily reveals the mechanisms of spatiotemporal coding of the odor information from olfactory sensory neurons and odor recognization of the bulb.It lays a good foundation for the further studies of the different mechanisms of PG,MC and GC cells in olfactory bulb coding as well as the odor pattern recognization based on the bulb physiological structure.关键词：olfactory system;neural network modeling;olfactory bulb;olfactory coding2|923|1更新时间：2025-07-16
- 摘要：This paper analyzes the factors which affect the fairness between TFRC protocol and TCP protocol,and introduces two weighted coefficients to calculate the packet loss event rate which is used to calculate the sending rate in equation of TFRC protocol so as to adjust the sending rate based on network congestion level. Simulation results show that through this method,the fairness and smoothness of TFRC at different congestion levels are effectively improved,thus meeting the requirements of multimedia stream more effectively.关键词：TFRC;fairness;smoothness2|913|1更新时间：2025-07-16
- 摘要：TCP throughput is one of the key concepts of computer network,and its estimation is very important for many research and application domains.Packet loss pattern is crucial to deduce a TCP throughput model,and can affect model's precision directly.Therefore,a new TCP throughput model GT(Gilbert Throughput)is presented by modeling a TCP congestion control mechanism based on Gilbert four-state model that is used to represent the packet lost behavior of end-to-end internet path.Experiment results show that GT matches the results better than Goyal model,and can predict the throughput of TCP flows more precisely in actual network.关键词：network measurement;TCP throughput;congestion control;gilbert packet loss pattern2|1509|1更新时间：2025-07-16
- 摘要：The Human-Computer Interaction (HCI) technology realm has witnessed the rise of new HCI channels in recent years,which is powered by enhancement of various signal-processing methods following the computer capacity boost in the last decade.Brain-Computer Interface (BCI),which has attracted broad notice,is one of such channels.The P300-based BCI utilizes the endogenous P300 event related potentials to decode user’s intention.Most of previous applications of P300-BCI systems were targeted at English letter input.Our research developed the first Chinese input online BCI system based on P300 potentials.We took advantage of the stroke-comprising characteristics of Chinese characters to simplify the P300 induction interface,and designed the Chinese typing virtual keyboard accordingly.Online human experiments showed that the Chinese BCI idea is viable,and further improvement of the system could provide the Chinese-speaking paralyzed patients a new option to restore their body functions.关键词：brain-computer interface (BCI);P300;Chinese input;virtual keyboard2|1858|10更新时间：2025-07-16
- 摘要：For the limited computing efficiency of existing artificial immune models,a novel method is proposed to improve their searching capabilities,which makes use of some coordinative mechanisms with referring to such kind of models or concepts in natural world. With regarded to the fact that a vaccine itself evolves along with population’s evolution,this method aims at setting up a coordinative relation between the population and the vaccination-base during the whole evolutionary process,in order to raise the probability with which the algorithm finds the optimum or a satisfied solution. Both theoretical analysis and the simulation on multi examples of TSP problem,show that this model appears batter than traditional genetic algorithms,and the searching efficiency for the globally optimum is greatly improved as well.关键词：intelligent computing;immune algorithms;cooperation evolution;TSP4|616|4更新时间：2025-07-16
- 摘要：Multiple sequence alignment is necessary and important for reconstructing evolutionary trees and comparing haplotype sequences.Center star method is always used to deal with lots of long sequences.However,square time complexity is a bottleneck for large data.In this paper,we propose a novel keyword tree based algorithm for improving the center star method.Aho-Corasick algorithm is employed to match a set of substrings and the rest regions are aligned by dynamic programming.Experiments show that the improved method runs faster than the initial center star method and clustalx.关键词：multiple sequence alignment;center star method;keyword tree;Aho-Corasick algorithm;bioinformatics2|1138|3更新时间：2025-07-16
- 摘要：By using the method ,employing the variation in resistance of helix with temperature,the heat dissipation capability of the helix traveling-wave tube slow-wave structure(SWS) made by several helix assembling methods have been tested.The results of this study have demonstrated that four assembling methods,i.e.,the graphite wrapping method,the hot insertion method,the sputtering brazing method and the diffusion brazing method have better heat dissipation capability of the SWS than that of the cold compress method and the molybdenum wrapping method .The SWS made by hot insertion method has a smaller microwave reflecting than that of the graphite wrapping method.The diffusion brazing SWS have a little better heat dissipation capability and lower microwave losses than that of the sputtering brazing SWS.These results can lead to improved helix TWT designs and performance.关键词：traveling-wave tube;helix slow-wave structure;heat dissipation;non-brazing helix assembling method;brazing helix assembling method2|674|2更新时间：2025-07-16
- 摘要：Reducing the dimensionality of data without losing intrinsic information is a hotspot in machine learning and data mining.In this paper we propose a new dimensionality reduction algorithms call IKLDA(improved kernel Linear discriminant analysis) on the ground of graph embedding framework.Our method not only can detect the information hidden in digital images but also reduce the dimensionality.Theoretical analysis and experiments show that our new IKLDA algorithm is effective in steganalysis and is more precise than the other traditional dimensional reduction methods.Furthermore,our method promotes development of visualization in the application in steganalysis.关键词：steganalysis;dimensionality reduction;graph embedding framework;visualization2|894|2更新时间：2025-07-16
- 摘要：The echo’s mathematic model of movement target for wideband linear frequency modulated signal in STRETCH processing is deduced,which is demonstrated to be a muticomponent polynomial phase signals (mc-pps).The defect of processing mc-pps using time-frequency analysis and polynomial phase transform (PPT) are pointed out.And then,a new algorithm of estimation movement parameter and reconstruction scattering centers of extend radar target is proposed,which can avoid loss of energy and frequency resolution of auto-correlation by using double-dechirp.According to the characteristic of power spectrum,the proposed algorithm adopts power maxima criterion suppressing crossterms and improves performance of parameter estimation by using iterative algorithm.Furthermore,the ESPRIT algorithm supersedes FFT algorithm for improving estimation accuracy.Simulation results show that the proposed method can extract movement feature and reconstruct scattering centers effectively,even when SNR is low.关键词：muticomponent polynomial phase signals;interference-term;moving target;parameter estimation2|922|0更新时间：2025-07-16
- 摘要：For color host images,a novel adaptive watermarking algorithm based on hypercomplex Fourier transform is proposed in this paper.Firstly the color host image is transferred into hypercomplex frequency domain.Then some real parts of the hypercomplex frequency spectra of the color host image are selected.Based on the different mask properties of the human vision system about the texture,edge and luminance of the color host image,the selected frequency spectra are put the different mask weights for the embedded watermark.As a result,an adaptive watermarking algorithm for color host images in hypercomplex spectrum domain is realized.Experimental results show that the robustness and insensitiveness of our method are much improved by the adaptive masks of the color image.Its anti-attacking capability is also much better than the hypercomplex watermarking algorithm without adaptive masks.Comparison results with the known ones in literature verify such superiorities of the proposed algorithm.关键词：digital watermarking;adaptive watermark;hypercomplex;hypercomplex Fourier transforms2|871|5更新时间：2025-07-16
- 摘要：A new segmentation-based method to reduce the metal artifacts in computed tomography is proposed.The proposed method firstly uses the anisotropic Gaussian filter to suppress the noise and to smooth streak artifacts of the CT image.Next,based on maximized the difference of mutual information segmentation,the metal image is segmented from the filtered image.Then,a feedback based interpolation algorithm is used to recover the original sinogram in the projection domain.The final image is reconstructed by the filtered-back-projection method from recovered sinogram.The proposed method has been tested on real phantom and clinical CT images.关键词：CT metal artifacts;anisotropic Gaussian filter;maximized the difference of mutual information segmentation;feedback based interpolation4|1398|8更新时间：2025-07-16
- 摘要：An improved method for Non-Linear Frequency Modulation (NLFM) signal design is proposed based on window functions method.The minimum peak sidelobe suppression correlator of NLFM signal,based on window functions,is solved by convex optimization,and based on which a new NFLM signal is presented.its range sidelobe can be farther decreased by multi-iterative operations.Given the limited mainlobe width,a lower range sidelobe can be achieved with the presented method,and also,the presented algorithm can be suitable for the NLFM signal design with small time-frequency product.The proposed method has many advantages over the existing ones,such as design flexibility and quickly convergence.The validity of method is demonstrated by the simulation results.关键词：non-linear frequency modulation;convex optimization;peak sidelobe suppression correlator;window functions2|1096|3更新时间：2025-07-16
- 摘要：An echo cancellation and noise suppression algorithm is presented by using improved adaptive step-size non-linear filter technology,and a single-chip implementation for this algorithm is proposed.This chip is fabricated in a 3.3V/1.8V 6-metal 180 nm mixed-signal CMOS process,and its acoustic echo cancellation performance can reach 70 dB,noise suppression performance is 20 dB and side tone cancellation is 30 dB.This chip includes a 16-bit DSP,three 14-bit sigma-delta ADC,two 16-bit sigma-delta DAC and embedded ROMs and RAMs,which also provides USB,UART,I2C and PCM interfaces.Experimental results show that the chip supports full-duplex mode,faraway hand-free function and dual microphones input and it complies with ITU-T G.165 standard. With very low power consumption,simple peripheral circuits and strong self adaptation capability,it can be widely used in various applications such as portable Bluetooth hand-free car kit,GPS and instant communication.关键词：echo cancellation;noise suppression;hand-free communication;system on chip(SoC)2|1232|0更新时间：2025-07-16
- 摘要：This paper presented the multiple classifier based walking pattern recognition algorithm,which could identify three walking patterns:horizontal walking,up and down staircase walking.Three-dimensional accelerations during walking were acquired from the wireless accelerometer device fixed on the back waist.The discrete wavelet transformation was applied for time-frequency analysis.The time-frequency features associated with the main frequency band of the motion,walking cadence and the correlation between the vertical and forward acceleration signals were combined to design a multiple classifier.A set of 360 gait samples involving 10 people were used for test,giving an overall recognition accuracy for 96.1% when the walking cadence range was within 1~3Hz,and this algorithm was less dependent on individuals.关键词：walking pattern;wavelet transformation;time-frequency feature;multiple classifier;accelerometer2|1136|9更新时间：2025-07-16
- 摘要：This paper presents an improved dynamic programming(DP)based ray-space interpolation for arbitrary view rendering.Different from the conventional DP method,a smoothing constraint of inter-scanlines is applied to eliminate the "streaking" artifact,and the most time-consuming step of computing matching cost is carried out by an incremental computation scheme.Then,dense ray-space data are interpolated by a view-centered disparity estimation method.Finally,arbitrary viewpoint image with high quality can be rendered from this dense ray-space easily.The proposed scheme is evaluated on the Middlebury data set and 3DTV test data.The experimental results show that the PSNR and computational efficiency of the proposed rendering method are much higher than that of the other two schemes.关键词：arbitrary view rendering;dynamic programming;ray-space interpolation2|748|2更新时间：2025-07-16
- 摘要：This paper proposes a genetic sequential IB algorithm.It takes several seeding solutions of the basic sequential IB algorithm as initial population,and then integrates this population into a solution using the integration operator.Sequentially,some certain positions of the obtained solution are selected and mutated iteratively based on the defined instability statistic.After mutation of several generations,the iterative process terminates and a more optimal solution is obtained.Experimental results on the benchmark data sets indicate that the proposed algorithm outperforms the sequential IB algorithm in both the accuracy and the efficiency.关键词：IB theory;sIB algorithm;genetic variation;mutual information2|1040|1更新时间：2025-07-16
- 摘要：Traditional Snake model is sensitive to the initialization of contour,easily relapsed into a local optimal in a high noise image,and invalid for the image contour with deeply narrow concavities.By designing the image transform operator to derive the region force from the region information included in the interested object,and using Green formula with the conversation ability between region integral and curve integral,a novel snake model R-Snake(Region Snake)was proposed in this paper to extract the contour of interested object,which more directly introduces region information to active contour model in terms of the force balance equation.Because of evolving the contour curve by using both region information and gradient information,our proposed method could not only extend the initialization of contour and alleviate the sensitivity to image noise,but also improve the capacity to converge into complex boundary.Compared with the traditional Snake model,experimental results demonstrated its feasibility and robustness,especially for the images with high noise and deeply narrow concavities.关键词：R-Snake model;region information;Green formula;contour extraction2|1522|6更新时间：2025-07-16
- 摘要：There are 11 kinds of communication messages among nodes in BT system.Flow sent by HAVE,REQUEST and PIECE messages is a main part of all.In order to improve the network transfer efficiency and reduce the management expenses in file’s transferring,the research has focused on HAVE message,and proposed a improvement scheme to HAVE message—the MultiHave message.It shows by the experiment that MultiHave message has improved systematic performance effectively.关键词：BitTorrent;Peer-to-Peer;HAVE message;MultiHave message2|822|0更新时间：2025-07-16
- 摘要：This paper has extended and improved the method of distance-preserving projection which substitutes an estimated geodesic distance for the conventional Euclidean distance.It can nuroll the data of nonlinear surface correctly and preserves exact distances of each data point to its nearest neighbor point and to some other near neighbors.In order to choose a suitable neighborhood size effectively,the P-ISOMAP algorithm which is much less sensitive to the neighborhood size is used.Contrasted with the original method and ISOMAP and other methods,this paper can reduce dimensionality and visualize more effectively.For classification,this paper develops new classification techniques.The experiments prove that the method has taken the excellent effect in visualization,dimensionality reduction and classification.关键词：distance-preserving projection;ISOMAP;minimum spanning tree(MST);geodesic distance;P-ISOMAP2|1071|4更新时间：2025-07-16
- 摘要：Miao-Wang-Miao-Xiong’s anonymous E-Prosecution scheme was analyzed.The security flaws were pointed out.The original scheme can’t guarantee the security of prosecution contents and effective reward support.We design the attack methods to break the two properties.In order to design an anonymous E-Prosecution scheme with reward support,we make use of the secure public key encryption scheme from bilinear pairings,secure designated verifier ring signature scheme to propose the design model of anonymous E-Prosecution scheme.Through security analysis,our design model is secure.关键词：anonymous E-Prosecution;designated verifier ring signature;bilinear pairings2|944|3更新时间：2025-07-16
- 摘要：The most typical models of spatial topological relations are Region Connection Calculus(RCC)and 9-intersection model.However,there are few contributions on topological relations of concave regions in which the representative model is Cohn's RCC23.There are some limitations of RCC23 especially in practical applications due to its less expressiveness.On the basis of Egenhofer's and El-Geresy's general methods for spatial reasoning,this paper completed the following work:9-intersection matrix is extended to 16-intersection matrix;RCC23 is refined to RCC62 based on 16-intersection matrix;the Conceptual Neighborhood Graph(CNG)and the Closest Topological Relation Graph(CTRG)of RCC62 are given;reasoning rules for RCC62 composed relations are presented.There are 39 new relations in RCC62,which is more expressive than RCC23;Base on the reasoning rules of RCC62,the composition table of RCC62 can be derived.关键词：topological relation;simple concave region;convex hull;RCC23;9-intersection2|881|2更新时间：2025-07-16
- 摘要：A test data compression scheme based on mixed fixed and variable run-length coding in virtual block(MFVRCVB)is presented.In the scheme the test vectors are concatenated to a stream first and then this stream is divided fixed length block.In every block the one-bit-representation or the maximum one-bit-representation is search to reduce the number and length of runs.Then the left data in every block is encoded by using the run-length encoding.This reduces the volume of data needed to be encoded and breaks the limitation by the volume of original test data in tranditional run-length schemes.Experimental results show that the proposed scheme obviously outperforms the traditional coding methods in the compression ratio,such as Golomb,FDR,VIHC,v9C coding.关键词：test data compression;coding;fixed length coding;variable length coding2|1128|11更新时间：2025-07-16
- 摘要：Bayesian network is one of the most important methods for representing and inferring with uncertainty knowledge,causal relation between variables is a key property for modeling the knowledge,so it is an important problem to orient the edges.There are some problems in the exist methods:(1)the computational complexity of the algorithms is high;(2)orienting the statistical indistinguishable edges may inconsistent with the domain knowledge.This paper presents an algorithm which combining the constraint approach and score search approach to orient the edges.The time of zero order and first order conditional independent test is polynomial;The search space can be decomposed to sub graph,which improving the efficiency of the algorithm.The output of the algorithm is largest chain graph,which just orienting the statistical distinguishable edges,keep the indistinguishable edges undirected.This graph present the causal relation more accuracy,and more convenient for combining domain knowledge.关键词：bayesian network;orienting edges;Markov equivalence class;chain graph2|821|3更新时间：2025-07-16
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Thermal Characteristic of a Novel Flat Plate Heat Pipe for Hybrid Integrated Power Electronic Module
摘要：This paper presents a novel flat heat pipe filled with negative-ion water to take the place of copper heat spreader of commercial power electronic module to solve the issues of heat concentration.With increasing of dissipated power on the die,the heat transfer coefficient on evaporator increases,and then the thermal flux density vector transfers from heat source to the evaporator vertically.In the conditon of 186W/cm2 thermal load,the junction-to-case (JC) thermal resistance descreases to the half of commercial power module.The dynamic performance shows that the chip temperature is lower 46℃ than that of commercial module using 3mm copper heat spreader with 225W pulse thermal load and forced air cooling heat sink.3|1321|2更新时间：2025-07-16 - 摘要：The accuracy of motion objects detection is low for outdoor complicated visual surveillance,so a background reconstruction algorithm used in background subtraction motion objects detection is proposed.The algorithm integrates the stabilization duration with appearance frequency,and uses weighted intensity histogram to confirm the background probability of quantity interval.Based on the probability values and distributing,it uses the intensity space correlation to amend the background,and realizes the background reconstruction.The experimental results show that the reconstructed background conquers the influence of motion objects in training phase,and in motion objects detection application,it is applicable in the situation existing background fluctuation and small camera displacements etc,and it improves the accuracy of detection.关键词：motion objects detection;background reconstruction;weighted intensity histogram;background probability;space correlation2|931|4更新时间：2025-07-16
- 摘要：A low power inductively-coupled microwave plasma source based on planar spiral microstrip at 2.45GHz is presented in this paper.The resonant characteristics of the plasma source are analyzed with equivalent transformer coupled circuit model,and the discharges in various gas pressure based on the interrelation between absorbed power and plasma impedance are studied.The research shows that air plasma is ignited in low pressure as the input power is less than 220mW,and Ar plasma is ignited in atmospheric pressure as the input power is less 1.5W.The resonant frequency and S parameter of low power microwave plasma source change with excitation of microwave plasma.This may be a theoretical guidance for miniaturization of inductively-coupled microwave plasma source.关键词：planar spiral microstrip;low power inductively-coupled microwave plasma source;resonance;gas discharge;S parameter2|990|1更新时间：2025-07-16
- 摘要：A simultaneous localization and mapping (SLAM) based on combined filter is brought forward and use the statistic theory to evaluate the consistency of SLAM algorithm.It decomposes the joint posterior probability distribution into robot path part and feature map part,which make the filter become low dimensional filter and can improve the computational efficiency.The constrained unscented kalman filter (CUKF) make the proposal distribution closer to the posterior probability distribution with new observations and the robot pose can be estimated accurately.The extended kalman filter (EKF) is used to update the feature map location.The simulated experiments show this method is effective and reliable to realize SLAM and its precision can be better than other SLAM algorithms in some environment.关键词：mobile robot;combined filter;simultaneous localization and mapping;consistency;particle filter;Kalman filter2|1906|6更新时间：2025-07-16
- 摘要：Focusing on intensity-modulation/ direct-detection (IM/DD) partially coherent optical links using the on-off-keying scheme,the analytic models of channel capacity,channel bit-error-rate and link outage probability were established.On the basis of these models,the calculations of channel capacity,channel bit-error-rate and link outage probability for both fully and partially coherent optical links were performed,and then the comparative analysis for the two types of links was presented.The optimization model for the initial coherent degree of a laser was proposed with the situation when the transmitted power was limited.The performance of optical links through atmospheric turbulence using partially coherent beams is better than fully coherent beams,and propagation using a partially coherent beam is an effective technique for mitigating the turbulence-induced impact.关键词：channel capacity;bit error rate;outage probability;optical wireless communication;partially coherent beam2|1486|7更新时间：2025-07-16
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