最新刊期
卷 40 ， 期 10 ， 2012
- 摘要：Cloud model uses two-order Gaussian distribution to produce cloud drops whose distribution displays high kurtosis and fat tail with power-law decay.In sociology and economics,many phenomena have been found to share high kurtosis and fat tail because of preferential attachment in evolution processes.This paper tries to investigate the relation between Gaussian distribution and fat-tail distribution,and to construct fat-tail distribution based on Gaussian distribution with iterations to depict more uncertain phenomena.The comparative study on parameters of high-order Gaussian distribution with iterations and cloud model can provide a new thought and method for the research of reverse solution of high-order cloud model.关键词：Gaussian distribution;kurtosis;fat tail;cloud model2|2|4更新时间：2025-07-16
- 摘要：This paper proposes to use connection identify (CID) to mark the process of obtaining a service,and add connection identify mapping server (CMS) to achieve the management of connections.CMSs make the core network and access network be separated.And through the mapping between CID and IP in the CMSs,the communication is separated to three steps.This mapping communication mode makes the sending of packets be based on CID instead of IP address.Thus,the controllability and manageability of connections have gained a remarkable increasing.Moreover,this paper has particularly represented the advantages of the mapping communication,and the compatibility of current applications.In addition,we give some countermeasures aimed at the new network attacks which the mapping communication mode may bring about.At last,the experimentation results reveal the specific performances of mapping communication mode.关键词：Connection Identify (CID);network architecture;mapping communication;identify mapping2|2|1更新时间：2025-07-16
- 摘要：In order to discover the public opinion leader community in a web forum,a heterogeneous network is constructed to represent the relationship between the topics and their replies.By quantifying the influences of forum users,a forum opinion leader community mining algorithm (FOLCM) is put forward.The algorithm is evaluated with real large-scale web data from the TianYa forum.The results demonstrate the effectiveness of the forum opinion leader community mining algorithm.关键词：network community;community mining;public opinion leader;heterogeneous network2|2|5更新时间：2025-07-16
- 摘要：QoS-aware automatic service composition is committed to synthesize the correct work plans from huge amounts of web services based on the functional quality requirements of the users.It is highly effective in fields such as service composition modeling,correctness checking,etc.Noticing that to give users more choices can meet the diversified demands and eliminate the possible performance bottle necks,we extend our tool,QSynth,to a new system QSynth-TopK which supports the query of top k work plans.In this system,top k work plans are generated orderly by iteratively replacing the web services in the optimal composition.In theory this way is proved accurate.Evaluations show that QSynth-TopK achieves stable and outstanding efficiency with respect to large composition scenarios.关键词：automatic service composition;Quality of Service;top k;graph search2|4|1更新时间：2025-07-16
- 摘要：L2P(Y) signal tracking in dual-frequency receiver can be implemented by employing semi-codeless method.However,the actual L2P(Y) signal carrier to noise ratio is very low due to squaring-loss.As a result,higher performance requirements are needed for L2P(Y) signal tracking loop.This paper presents a way of using dynamic-aided L2P(Y) tracking.Loop design details are given,and the various factors affecting the performance of the loop are discussed in detail.The performances of the dynamic-aided loop and the none-aided loop are compared through computer simulation.Simulation results show that dynamic-aided method can track L2P(Y) signal in lower carrier to noise ratios effectively.关键词：GPS;dual frequency;semi-codeless;Z-tracking;squaring loss;dynamic-aided2|2|3更新时间：2025-07-16
- 摘要：UWB(Ultra Wideband) radio system is easily affected by strong narrow band interference.Traditional interference suppression methods using adaptive notch filter as a preprocessing unit can hardly be used due to high sampling speed in UWB receivers.In this paper,we proposed a novel parallel notch filter based on TDM (Time-division multiplexing) technique,which can effectively track and eliminate multi-band interference,and extremely raise the interference tolerance margin of the UWB wireless communication system when it is used as a preprocessing unit before dispreading.Moreover,the filter structure has such advantages as good stability,high convergence speed,low signal distortion.The numerical results validated the expected performance and properties.关键词：ultra wideband;TDM (Time-Division Multiplexing);interference;adaptive2|2|0更新时间：2025-07-16
- 摘要：Obviously the HAP doesn’t keep stationary all long and the HAP state of rotation and swing will impact the performance of HAPS communication seriously.By far,all the research work assumed that the high altitude platform is stationary and offset caused by movement of the high altitude platform is compensated.Therefore traditional method can not resolve the problems caused by the instability of high altitude platform and effects on the performance of HAPS communication by instability of high altitude platform are researched profoundly.A wireless link model which reflects the states of HAP is proposed and the problems caused by the instability of high altitude platform are resolved.Lastly the validity of the model proposed uhis paper is proved by numerical analysis and simulation.关键词：high altitude platform stations;instability;wireless link;performance effect2|3|2更新时间：2025-07-16
- 摘要：In this paper,we propose a network coding based multi-relay cooperative handover mechanism MRH,for multi-hop handover scenario in wireless internet of things.MRH adopts a route detection algorithm based on potential energy field.One mobile terminal can register on multiple roaming area through intermediate cooperation.Based on network coding,mobile terminal establishes reliable,flexible handover connections with multiple network access points,then smooth handover between multiple internet of things can be realized.关键词：network coding;Internet of Things;handover2|2|1更新时间：2025-07-16
- 摘要：Aiming at the random process with periodic changing characteristic,A new estimation method under the case having only measurement model is proposed in this paper.Firstly,the discrete output equation,output equation with blocking form,and output equation between point sample and the block vector of estimated state are taken.Secondly,by using the periodic random walk characteristic of estimated variable,the state models are established.Thirdly,based on strong tracking filter algorithm,three estimation methods such as real time point filter,semi-real time block filter,and real time block filter are proposed for the un-modeled random variable system with only output measurement.Finally,computer simulation is demonstrated to compare the performances of three proposed filters.关键词：Kalman filtering;random walk;output measurements;block estimation;strong tracking filter2|4|1更新时间：2025-07-16
- 摘要：Traditional face recognition algorithms usually handle variations in illumination and pose independently.Therefore,it is difficult to obtain the global optimal recognition performance.To this end,we propose an affine minimum linear reconstruction error (AMLRE) algorithm based on the non-rigid characteristics of human faces in this paper,which combines an affine transformation model and the idea of patch with a linear reconstruction model. Our algorithm simultaneously handles illumination variations as well as compensates the local area alignment errors caused by pose variations,which achieves much better recognition performance.Comprehensive experiments on several public face datasets clearly demonstrate that our proposed algorithm is robust to both illumination and pose,and thus outperforms most state-of-the-art methods.关键词：face recognition;linear reconstruction;affine transformation;lucas-kanade algorithm2|3|2更新时间：2025-07-16
- 摘要：Based on the idea of hypercube constellation and code theory,two kinds of relay-coding matrix are designed for multi-user single relay model,that provide the schemes for resolving how to enhance the performance of relay transmission in wireless communication.The performance of system with different relay-codes are deduced,compared with the system without relay-codes through simulation,the result shows that additional gain can be achieved and the relay-code based on code theory has performance advantage.Compared with system without relay-code,the additional complexity of two relay-coded systems are analyzed.The analysis result shows that the relay-code based on hypercube constellation has advantage on additional complexity when some condition is satisfied.关键词：multi-user;relay-code;hypercube constellations;product codes2|2|0更新时间：2025-07-16
- 摘要：According to the sparse characteristic of the PPM modulated signal,this paper proposes a coding method making use of a low density matrix,and decoding with maximum a posteriori probability rule.Compared with the regular LDPC,the proposed method has better error correction ability and decoding speed when using hard or soft decisions.关键词：PPM modulation;low density matrix;additive white Gaussian noise (AWGN);maximum a posteriori (MAP)2|2|2更新时间：2025-07-16
- 摘要：A new local mean value computing algorithm is proposed based on the theory of the mean value matrix filter sets.The algorithm computes the weighted mean value of the matrix by multiplying a mean value filter matrix to each side of it.This special matrix can be calculated quickly and simplify the process of envelope computing.Based on the mean value matrix filter sets,a fast two-dimension EMD algorithm is proposed.Experiments show this algorithm works well on image fusion.It can also reduce the computation time by 1/100~1/1000 than that of the traditional EMD.关键词：fast algorithm of empirical mode decomposition (EMD);mean value filter matrix;image fusion2|2|1更新时间：2025-07-16
- 摘要：Focusing on multi-focus image fusion,this paper presents a Curvelet domain method based on grey relation of similarity for visible-light images.In this method,source images are respectively decomposed by multilevel discrete Curvelet transform first.Then,after high frequency coefficients were divided into small blocks,grey Euclid relational degrees of grey theory are used to compute the similarities of these blocks,on which the high-frequency coefficients are fused,while the arithmetic mean method is used to fuse the low-frequency coefficients.Finally,a fused image is reconstructed with the fused coefficients by performing the inverse Curvelet transform.Experimental results show that the proposed method is superior to pyramid-based methods and wavelet-transform-based methods in terms of entropy,standard deviation and clarity.关键词：image fusion;Curvelet transform;grey relational analysis;similarity2|2|6更新时间：2025-07-16
- 摘要：An objective global evaluation algorithm of segmentation results is proposed,which is based on computing the deviation of the segmentation results from reference segmentation.By taking into account image understanding view,the discrepancy between two results is weighted based on spatial contextual information,thereby obtaining the different weightiness.Moreover,relative distance,foreground and background searching distance are introduced into the proposed metric,and the value of this metric is invariant to the segmentation images with varying scale.In order to overcome the irrational evaluation caused by the excessive over-segmentation and under-segmentation,a penalized term is proposed.Experiment results prove that our evaluation accords with the view of the image understanding and it is more global and robust.关键词：segmentation evaluation;discrepancy metric;understanding weight;zoom invariant;penalized term2|3|3更新时间：2025-07-16
- 摘要：Based on the balance characteristic of the data-path when combining QDI asynchronous logic and the four-phase protocol with dual-rail encoding,the random swapping of the data-path rail can be implemented,so the balance of the average power for every data-path can be implemented,and the correlation between the data and the power can also be eliminated.But because of using the multiplexer for the random swapping,the current method will induce the system's ability of against power analysis attack to be weakened.So the method of QDI random data-path swapping,which is based on the metastability is put forward.By adopting the two-level swapping structure,the metastability generator and metastability filter,the random swapping between the data-path group and the data-path can be implemented.Simulation results show that,the method has the characteristic of preferable power balance,and the leakage of the side-channel information brought by the differences of the parasitic capacitor and the load capacitor,can also be counteracted.关键词：power analysis attack;QDI logic;metastability;random path swapping2|2|1更新时间：2025-07-16
- 摘要：To provide a large,scalable embedding capacity and maintain a good visual quality of stego-image,this paper presents a novel steganography.According to human visual characteristic,the algorithm divides an image into smooth area,transition area,and edged area by the difference between the maximum pixel value and the minimum pixel value of 3 neighboring pixels;according to the characteristics of the module cycle,it uses modulus function with security features to adaptively embed different bits information into a pixel in 3 different areas with one of the embedding schemes.Different embedding scheme gets different rates of embedding and visual quality of stego-image.Experimental results show that the algorithm can maintain a high embedding rate while maintaining good visual quality of stego-image,and good security.关键词：steganography;side match;pixel-value difference;modular function2|2|2更新时间：2025-07-16
- 摘要：This paper proposes models for analyzing the security of decoy-state quantum key distribution (QKD) with state-dependent imperfections.With the privacy amplification method of QKD’s post-processing techniques,we introduce the decoy-state method used widely in QKD system to estimate the phase error rate more accurately than the case without decoy-state method.Based on this,we obtain the formula of secret key generation rates for decoy-state QKD with state-dependent imperfections,and characterize the relationship among key generation rates,state dependent parameter,detection efficiency and transmission distance.Numerical simulations indicate that the secure key generation rates’ tolerance to state-dependent imperfections decreases with the growing distance,but increases with the improving detection efficiency,which,to some extent,show the validity of the formula we obtain.关键词：quantum key distribution;state-dependent imperfections;decoy state;practical security2|2|2更新时间：2025-07-16
- 摘要：We use the method of minus to mix the public key of MI and TPM so that we propose a MPKC signature scheme based on MI and TPM.It is proved that the new scheme can resist high order linear equation attack,rank attacks,XL&Grbner basis attack,differential attack.It enhances security apparently and has some advantage on the length of signature,signature generation and the size of private key.关键词：multi-variable public key cryptography;digital signatures;MI;TPM2|2|2更新时间：2025-07-16
- 摘要：A modified artificial bee colony (ABC) algorithm based blind source separation (BSS) method is proposed in this paper,aiming at the problems of slow convergence and low computational precision of existing blind source separation methods.The modified ABC algorithm can adjust the step size function of the selected neighbor food source position adaptively.On the other hand,it takes advantage of the information of the global best solution to guide the search of candidate solutions to improve the exploitation.The modified ABC algorithm balances the exploration and exploitation which contradict with each other well,so it can achieve good optimizate performance.The new BSS improves the separation precision and the stable performance.Experimental results demonstrate that the proposed BSS can separate linear and instantaneous mixed signals effectively.Compared to the other approaches,the proposed method not only obtains better separation performance,but also has a faster convergence speed.关键词：blind source separation;artificial bee colony;neighborhood position;adaptive2|2|14更新时间：2025-07-16
- 摘要：A Gaussian Mixture Model (GMM) based speech enhancement method in compressed domain used for ITU-T G.722.2 wideband speech codec is proposed to take full advantage of the prior knowledge of the Immittance Spectral Frequencies (ISFs) for the clean speech.Firstly,GMM is adopted to model the joint probability density of feature vectors which are composed by the ISFs of noisy speech and clean speech with the corresponding gain scaling factor.Secondly,an optimal Bayesian estimation of feature parameters derived from clean speech is obtained under the minimum mean square error (MMSE) criterion.To be compatible with the DTX (Discontinuous Transmission) mode,the logarithmic energy is attenuated and the ISFs remain when a SID (Silence Insertion Descriptor) frame is received.Furthermore,if ao erased frame is received,the bit stream is unchanged and the proposed method is performed on the recovered parameters for the memory update.The evaluation is conducted under the ITU-T G.160.The results indicate that,comparing with the reference method,the proposed method can produce larger amount of noise level reduction with better objective speech quality,while the SNR improvement remains acceptable.关键词：speech enhancement;compressed domain;Gaussian mixture model;Bayesian estimation;DTX;frame erasure2|2|6更新时间：2025-07-16
- 摘要：The recursion creation and decomposition of matrix is introduced into singular value decomposition (SVD),and a signal decomposition way,which is similar to wavelet packet and is called multi-resolution SVD packet,is realized with SVD.The decomposition and reconstruction algorithms of multi-resolution SVD packet are given.Besides,a method in which two-dimensional array is used to store the three-dimensional data of this packet is proposed so that the waste of computer memory can be avoided.The results of examples show that this packet has good ability to detect the faint change of signal,and the accurate position of faint change can be reliably detected,and furthermore,there is no distortion of amplitude and phase in detection result.In addition,this packet can effectively extract the weak fault feature from the complicated signal.In these two cases the processing results of multi-resolution SVD packet is much better than those of wavelet packet.关键词：singular value decomposition;multi-resolution SVD packet;wavelet packet;decomposition and reconstruction;signal processing2|2|4更新时间：2025-07-16
- 摘要：Based on binary two dimensional array with ideal auto-correlation,a class of quaternary two dimesional array sets with zero-correlation zone are constructed by using inverse Gray mapping.The proposed quaternary ZCZ array set is optimal according to the theoretical bound,and the parameters of which are flexible.Moverover,a construction of shift sequence sets is presented.Numbers of shift sequences can be constructed by setting different parameters,and quaternary ZCZ array sets can be proposed correspondingly.关键词：binary optimal array;quaternary array set;zero correlation zone;inverse Gray mapping2|2|1更新时间：2025-07-16
- 摘要：In order to overcome the state explosion problem in model checking the probabilistic temporal logic of knowledge,a three-valued abstraction is proposed.Our work includes three parts:first the three-value semantics of the probabilistic temporal logic of knowledge is defined on the abstract model,and the initial abstract model is build according to the equivalence partition of state space,and the preservation of satisfaction under the abstraction is proved;second the model checking algorithm of the probabilistic temporal logic of knowledge is proposed;third how to refine the abstraction by the minimal witnesses and counterexamples generated in model checking is shown.Finally,the abstraction is applied in model checking the Dining Cryptographer protocols.关键词：three-valued abstraction;model checking;probabilistic temporal logic of knowledge;counterexample2|2|1更新时间：2025-07-16
- 摘要：Aiming at the problem that traffic flow varying with the departure time has not been taken into account in static path optimization method,a path optimization method based on traffic flow prediction is proposed.First of all,a novel road-based model,based on the characteristics of traffic network and the human’s understanding to the road traffic network,is constructed.Then,a prediction method based on single time series is adopted to obtain the future information of traffic flow of road sections,and transportation cost of travelers for each section is estimated by the forecast result.Next,the change of road traffic situation during the traveling from the origin to the destination is integrated into path search process of improved A* algorithm by the estimated transportation cost,thus a high efficient dynamic improved A* algorithm for path optimization is obtained.Finally,the path-search examples show that the predicted traffic flow and measured traffic flow can march well,thus the path searching result can guide travelers to improve their driving efficiency.关键词：traffic flow prediction;path searching algorithm;road network model2|2|8更新时间：2025-07-16
- 摘要：In the coordinative path planning for distributed multiple missiles,an improved Voronoi diagram is introduced to construct a set of feasible flight paths of the missiles,and a model is presented for calculation of the cost of each path taking the threat and fuel into account.Aiming at minimizing the total cost of the paths and the greatest time difference of arriving of all the missiles,the multi-platform missile path planning problem is modeled as a distributed constrained optimization problem (DCOP),and is well solved with existed DCOP algorithms.A typical senario is simulated to verify the presented method.The simulation results show the optimized path planning can be obtained,the computational time cost,as well as the communication cost is moderate,and the method is validate in practical applications.关键词：multi-missile cooperation;improved Voronoi diagram;cooperative path planning;distributed constrained optimization problem5|2|4更新时间：2025-07-16
- 摘要：The mixture simulation system of virtual model and real equipment requests for clear real-time characteristics to the virtual model.The running time of existing photon transmission model is too long to meet the real-time requirement of simulation system.For this problem,we described the photon transmission in the multi-layer flat-type media utilizing its group characteristics,and the photons in the received plane using Gaussian distribution,then got the photon distribution in receiving plane according to the results of total numbers and 63.2% energy radius.Experimental results show that the trends and values of this method are basically consistent with the standard Monte Carlo photon transmission model in the same simulation conditions,and this method delivers a substantial increase in speed which can meet the real-time requirements of general simulation system.关键词：Monte Carlo;Gaussian assumption;photon transmission model;multi-layer flat media2|2|0更新时间：2025-07-16
- 摘要：In order to realize an nonlinear operations between fuzzy numbers and raise the accuracy of the approximation of fuzzy neural networks,the polygonal fuzzy numbers and a polygonal fuzzy neural network are introduced,and according to their extension operations to improve the classic conjugate gradient algorithm,in the iterative process,the optimal constants of the algorithm are obtained through the one-dimensional inexactitude A-G linear search method,and then a polygonal fuzzy conjugate gradient algorithm is designed under environment of polygonal fuzzy neural networks.Finally,utilizing a simulation examples,some good characteristics of this algorithm are illustrated,for example,low computational complexity,fast convergence and so on.关键词：polygonal fuzzy numbers;polygonal fuzzy neural networks;conjugate gradient algorithm;A-G algorithm2|2|5更新时间：2025-07-16
- 摘要：This paper introduces the concept of truth degrees of propositions in n-valued Lukasiewicz logical system by means of the infinite product of probability on the value domain.By discussing the properties of truth degree we illustrate that the truth degree satisfies Kolmogorov axioms.By introducing the concepts of uncertainty degree of formulas and essentialness degree of premises we prove that the uncertainty degree of conclusion is less than or equal to the sum of the product of uncertainty degree of every premise and its essentialness degree in formal inference.By using uncertainty degree we establish logic pseudo-metric space on formulas set,and proved that the logic pseudo-metric space has not isolated point.Moreover,we propose two different approximate reasoning models in the formulas set.关键词：Lukasiewicz n-value logic;truth degree;uncertainty degree;truth value state;pseudo-metric;approximation reasoning2|2|2更新时间：2025-07-16
- 摘要：With the deficiency of the published methods in the logic detection,a method of the logic detection and decomposition using the disjointed cubes and the Hamming distance is proposed.By employing the method,a cover of a logic function is decomposed into two disjointed parts.One is suitable for the Boolean logic implementation and the other is suitable for the Reed-Muller(RM) logic implementation.Furthermore,a novel approach for the logic detection is also presented in this paper.The experimental results show that the proposed method can give a quick judgment for a circuit to choose a proper logic during the logic synthesis for the most cases.关键词：Reed-Muller logic;Boolean logic;Logic detection;Hamming distance2|2|1更新时间：2025-07-16
- 摘要：In this paper,we analyze the algebraic weakness of KTANTAN32.Using related-key and meet-in-the-middle match attack,by algebraic deducing,we get some single-variable linear equations on some key bits and can recover these key bits instantly by solving these algebraic equations one by one.We can recover the key bits with only one pairs of related-keys,2 plaintext/ciphertext pairs.The time complexity and the memory complexity are all negligible.Which indicates that the KTANTAN32 is a very weaker cryptographic system.We conclude that using the NFSR update mode and the linearity of the key schedule together is the fatal weakness of KTANTANs.In order to prevent the cipher from meet in the middle and match attack,it is important to introduce some nonlinearity in the key schedule of this block cipher.关键词：block cipher;KTANTAN32;related-key attack;meet-in-the-middle attack;Non-linear feedback shift register (NLFSR)3|2|2更新时间：2025-07-16
- 摘要：There are not adequate independent and identically distributed training samples under a heterogeneous clutter environment.Thus,this paper proposes a knowledge-aided LCMV-STAP approach.Firstly,the weight of knowledge-aided LCMV-STAP model is solved,and then the formula of the relationship between the color loading factors and the constraint constants is derived.Finally,the two color loading factors are solved.The computer simulations show that knowledge-aided LCMV-STAP has a better output signal-interference noise ratio than the traditional approach under a heterogeneous clutter environment,and the detection probability of Adaptive Matched Filter is higher than that of the traditional approach.关键词：space-time adaptive processing;prior knowledge;color loading;clutter suppression;adaptive matched filter2|2|2更新时间：2025-07-16
- 摘要：Small electronic devices attached to the outer surface of standard capsule can potentially serve as a cost-effective method of validating medication compliance via electronic detection of an ingested e-pill inside the human digestive tract.In this paper,a passive chip design for such a device is discussed,and the detailed design procedure is given.For the volume-constrained device to achieve the best communication efficiency in the human body environment,an novel asymmetric architecture,which employs different carrier frequencies on Downlink / U plink data transfer,is proposed:the data communication from the reader to the ingested device (Downlink) is designed at 13.56MHz to minimize the signal attenuation through the human body,and the 915MHz band is used for the communication from the ingested device to the reader (Uplink) to achieve the best antenna radiation efficiency.A prototype micro-chip is fabricated using UMC CMOS 130nm technology,and measures 1500×800μm2.Experimental results demonstrate that the chip can be activated by -4dBm input power and achieves a data rate of 17kb/s in the Downlink communication.For the Uplink communication,the chip generates periodic pulses at 915MHz with a data rate of 0.75kb/s.关键词：electronic capsule;intra-body communication;wireless power supply;passive bidirectional communication2|2|2更新时间：2025-07-16
- 摘要：An incomplete fingerprint is one which contains noise and cannot be recognized in some areas.In some cases,it may not provide sufficient minutiae or ridge details for undertaking a normal matching process.This paper proposes an algorithm to reconstruct incomplete regions.The nearest minutiae and orientation field of neighborhood are combined to estimate the unknown orientation field.Previous outcome is used to connect disrupted ridges and recover missed minutiae based on ridge topology features,and arrive several rational schemes.They are measured by using entropy and the best is chosen.The experimental results demonstrate that proposed algorithm is effective in reconstructing incomplete fingerprint,and hence improve the performance of matching.关键词：incomplete fingerprint;reconstruction;minutiae;orientation field;entropy2|2|0更新时间：2025-07-16
- 摘要：A new method for passive cross location based on received signal strength (RSS) is proposed,which can eliminate ghosts under complicated electromagnetic environment.The relationship between array manifold and received signal strength of covariance matrix estimation is derived.Using the high order power of inverse spatial covariance matrix to get noise subspace,the received signal strength is obtained under the condition of known signal directions.From the knowledge of radio prorogation theory,the confidence of each cross location is computed by the relationship between received power and propagation decay.Through this way,the ghosts of cross location are estimated.The simulation results confirm the feasibility and effectiveness of the proposed method,which is robust to angle deviation and low SNR.关键词：cross location;false intersection points;received signal strength;the confidence of cross location2|2|8更新时间：2025-07-16
- 摘要：Focusing on the satellite signal acquisition with low time and frequency uncertainty,we propose a novel code acquisition algorithm based on discrete cosine transform (DCT).Firstly,we obtained a set of time-domain related vectors by partial matched filter (PMF).Then we performed the transform domain filtering and signal reconstruction for every candidate code phase.Because the signals and noise produced by PMF have different time-varying property,noise is greatly reduced and the signals have almost no loss,thereby increasing the probability of detection under the same probability of false alarm.The theoretical analysis and simulation results show that the detection algorithm can effectively improve the detection probability,and has a lower complexity.关键词：code acquisition;detection;discrete cosine transform;probability of false alarm;probability of detection2|2|1更新时间：2025-07-16
- 摘要：To solve the problem of constructing feedback functions of non-linear maximal length shift registers (NMLSR),the method to construct the feedback functions for NMLSR was proposed based on root function.First of all,we expatiated the classification method of the root functions modulo 3,proveded the characteristic state sets of the root functions and extracted the eigenfunctions of the root functions.Secondly,we synthesized the feedback function for the nonlinear m subsequence shift register according to the filter of the eigenfunctions on the root functions.Finally,we conducted a great number of calculations and analyses for new type sequences generated from the nonlinear m subsequence shift registers.The results show unanimously that the nonlinear m subsequences dose not only possess better period property,balance property and run-path property,but also the sharp autocorrelation property and the ideal linear complexity.关键词：nonlinear;feedback function;synthesize;filter;modulo 3;eigenfunction;pseudo-random sequence2|2|4更新时间：2025-07-16
- 摘要：Aiming at the effects of the array modeling errors,the second-order performance analysis method (i.e.,discarding the third-order and higher-order terms of the modeling errors) for the ESPRIT algorithm is proposed in this paper.Compared to the classical analysis method (i.e.,the first-order analysis method),the second-order analysis method can yield higher performance prediction precision,especially in the presence of large modeling errors.In addition,the presented analysis method is not only suitable for the case of the array manifold mismatch,but also applies to the case of the sensor noise model mismatch.The numerical experiments verify the superiority of the second-order performance analysis method in the presence of large modeling errors.关键词：ESPRIT algorithm;modeling errors;second-order performance analysis;array manifold mismatch;noise model mismatch2|2|3更新时间：2025-07-16
- 摘要：The assessment for the reliability design of Built-DFH in Magnetic head is very important.It recurrently uses the empirical data to instruct the production in the craft now.Unfortunately,the error is very large.Theoretically,everybody is simulating the reliability using the Matlab software.Owing to the limit of the cell size,the simulation algorithm will expire along with the rounding error superimposition.This article uses the ANSYS software.The experiment was to establish the basic parameters and select the appropriate cell type,material properties and give the finite element model of the head.The results according to the life prediction using the model above shows,the finite element model is effective.Furthermore,in new DFH in 50Ω,the strength of thermal effects is larger above 10% than the traditional shield.The regions with problems of the actual life failed samples are in the line of the corner.关键词：Dynamic Flying Height;reliability analysis;finite element;thermal effects;current crowded effect2|2|1更新时间：2025-07-16
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