最新刊期
卷 45 ， 期 6 ， 2017
- 摘要：Hybrid beamforming increases data rate through digital beamforming in baseband and analog beamforming in radio frequency.In order to analyze the capacity of indoor millimeter wave multiple input multiple output (MIMO) system based on hybrid beamforming,we investigate the zero force (ZF) receiver,the minimum mean square error (MMSE) receiver,and the matched filter (MF) receiver to obtain the data rate of the system under the optimal codebook-based beam selection in different circumstances.Simulation results show that whether the line-of-sight path is blocked,both the MMSE receiver and the ZF receiver achieve the performance which is close to the capacity under high total transmit power;under low total transmit power,the performance of the MMSE receiver is slightly better than the ZF receiver.However,the MF receiver shows poor performance.The system could adopt suitable receiver according to total transmit power and the complexity of receiver.The practical indoor wireless personal area networks (WPAN) could achieve high data rate short-distance wireless communications by applying the system we investigated in this paper.关键词：millimeter wave communication;multiple input multiple output (MIMO);hybrid beamforming;performance analysis527|545|3更新时间：2025-07-16
- 摘要：FMCW(Frequency Modulated Continuous Wave)radar with chirp sequence waveform is widely used in automotive applications.To resolve Doppler ambiguities in multi-target environment,we modify the classical chirp sequence waveform by adding a period of time delay before each chirp with even sequence number.The modified waveform is essentially a combination of two classical chirp sequences,one is composed of all the chirps with even sequence numbers,and the other one is composed of all the chirps with odd sequence numbers.The time delays in the modified waveform generate a phase difference between two beat signal groups corresponding to the two chirp sequences.Doppler ambiguities are resolved by the phase difference.Theoretical analysis and simulation results verify the effectiveness of the modified waveform.关键词：frequency modulated continuous wave(FMCW)radar;automotive radar;chirp sequence waveform;multi-target;Doppler ambiguity;two-dimensional FFT544|591|5更新时间：2025-07-16
- 摘要：The corresponding matched images are hard to obtain by the convetional scene matching localization method applied in UAV (Unmanned Aerial Vehicle) at a low altitude because of the small viewing coverage and the big capturing angle difference comparing with the satellite images.We propose a localization method based on instant dense 3D reconstruction.Firstly,we use a fast SLAM (Simultaneous Localization And Mapping) method to retrieve camera poses of image sequence captured by UAV.Secondly,cooperative denoising and optimization algorithm across multiple key frames is applied to obtain dense depth map and dense point cloud.Thirdly,a virtual view,the angle of which is similar to that of satellite,is generated by iterative optimizing method.Finally,we estimate the position of UAV by correspondence between the satellite map and the previous generated virtual view.Since the dense 3D point cloud integrates the information of multiple aerial images with small field of view and the viewing angles of some generated virtual views are close to those of satellite images,the proposed method provides a higher success rate and accuracy for localization.Experimental results illustrate the effectiveness and applicability of the proposed framework.关键词：UAV vision localization;3D reconstruction;SLAM375|465|11更新时间：2025-07-16
- 摘要：The patrol strategy of single or multiple EWAs (Early Warning Aircraft) that belongs to the same or different owner assigned by carrier formation aiming at multi-target air defense alert within synthesis combat area under warning time restriction is investigated.Firstly,the patrol strategy planning mechanism of EWA is analyzed,and that a patrol strategy rolling planning model aims at single or multiple isomorphic EWAs based on time subsection is presented;secondly,the realization process of the model is described;thirdly,aiming at the model solving,a parallel adaptive and tabu genetic algorithm of multi-master-single-slave structure is presented.Experiments show that the established model can realize the corresponding function of patrol strategy planning,and the proposed algorithm can solve the corresponding model efficiently.The validity of the model and algorithm is demonstrated.关键词：carrier formation;early warning aircraft;isomorphic;subsection optimization;parallel genetic algorithm (PGA)154|197|2更新时间：2025-07-16
- 摘要：Among the existing reconfigurable block cipher hardware structures,the special instruction processor does not achieve high throughput rate,while resource utilization of the reconfigurable block cipher processing array is low and mapping process is very complicated.Therefore,the reconfigurable asymmetrical multi-core architecture (RAMCA) for block cipher was designed.Mapping processes of typical structures,which were SP (AES-128),Feistel (SMS4),L-M (IDEA) and MISTY (KASUMI),was analyzed.Hardware implementation was designed and synthesized in a 65nm CMOS process.The experimental area is about 1.13sq mm while frequency reaches 1GHz.After the influence of the process is eliminated,the performance of RAMCA is higher than that of other special instruction processors and most of the reconfigurable block cipher processing arrays,such as Celator,RCPA,BCORE,etc.关键词：block cipher;heterogeneous multi-core;reconfigurable;parallel processing;cipher processor328|491|5更新时间：2025-07-16
- 摘要：In view of the collusion attack in cloud computing data location verification,collusion-attack-defensive data location verification protocols are proposed.Firstly,the system model of data location verification is given and the security threats are analyzed and the security definition is formalized.Then,the security positioning protocol is combined with the provable data possession protocol and the data location verification protocol in one dimension is proposed.In addition,the proposed protocol is proved to satisfy the security definition and to defend collusion attack.Based on the proposed protocol,the data location verification protocol in three dimensions is constructed.Finally,in three dimensions,the proposed protocol is tested and compared with the Lost protocol and the Geoproof protocol.The results show the proposed protocol can verify the specific geographical location of the server and can defend collusion attack of the adversaries.186|323|0更新时间：2025-07-16
- 摘要：In allusion to the problem that the scattering pattern of coupled target is distorted under the conditions of distance not satisfy the far field.By analyzing the relationship between near-field and far-field of coupling targets,an extrapolation method of "multiple-transmitter and multiple-receiving" is proposed.Firstly,the bistatic data of near-field at each angles are measured and extrapolated.Then the extrapolated data can be equivalent to "far-field transmitting,near-field receiving" data by the reciprocity theorem.Secondly,these data should be extrapolated again due to meet the "far-field transmitter,far-field receiving" conditions.Finally,diagonal elements is selescted to be the monostatic radar cross section (RCS)at each angles.By creating a dihedral angle model which has strong coupling mechanisms,through the simulation with FEKO and MATLAB,the far-field RCS is compared with the result of extrapolation by multiple-transmitter and multiple-receiving.The results obtained by this method show a good agreement with the RCS of the far-field,and the average error is less than 1dB,which verifies the method is effectiveness.关键词：near-field scattering;far-field RCS;coupled target;extrapolation method99|362|1更新时间：2025-07-16
- 摘要：To solve the problems that the existing privacy-preserving data aggregation relies on a network infrastructure,and data privacy is achieved by excessive encryption process,this paper proposes a privacy-preserving and concentric-circle itinerary-based data aggregation algorithm (PCIDA).Based on a well-designed ideal itinerary for data aggregation,PCIDA is not susceptible to network topology structure.In addition,PCIDA uses secure channel to ensure data privacy with no encryption/decryption operations during data aggregation.PCIDA performs data aggregation in parallel along with well-designed concentric-circle itineraries to achieve small delivery delay.Theoretical analysis and experimental results show that PCIDA enjoys low communication overhead and energy consumption,yet high safety and accuracy.关键词：Wireless sensor networks;privacy-preserving;data aggregation;infrastructure-free;concentric-circle384|302|0更新时间：2025-07-16
- 摘要：In non-Gaussian clutter environment,the range-spread target detection without secondary data is addressed,by utilizing two-step design procedure.Firstly,with known clutter texture component,the data under test is transformed into the Gaussian ones.And then the test statistic is derived by using the appropriate estimates of unknown clutter covariance matrix and target scatterer amplitudes.Secondly,by orthogonally projecting the data under test onto the orthogonal complement of signal subspace,the unknown clutter texture components are estimated.Consequently,the range-spread target detector based on subspace is proposed,and its constant false alarm rate (CFAR) property is also analyzed.It is showed that,under the classical non-Gaussian background,the proposed detector outperforms the compared ones,in terms of CFAR property and detection performance.In addition,its detection performance enhances to different extents,as the number of sensors,the number of target range cells or the clutter spikiness increases.关键词：wideband radar;range-spread target;orthogonal complement subspace;constant false alarm rate;secondary data113|282|1更新时间：2025-07-16
- 摘要：The conventional jamming approaches with dimensional singularity fail to gain jamming efficiency against space-time adaptive processor (STAP) in spatial-temporal domain.Therefore,a scattered-wave long duration sweeping frequency jamming method is proposed.In this method the scattered wave signal,which is generated by utilizing sweeping frequency signal scattering with Doppler bandwidth to certain locations from jammers,is employed to counter STAP radar.With this method,the jamming signal acquires space-time coupling feature and is continuous in space domain so that it cannot be identified or suppressed by STAP radar.The proposed method makes different Doppler frequencies between pulses hinder the radar from extracting signal Doppler frequency to occupy degree of freedom in processors.The simulation shows that the power spectrum of jamming signals can cover the whole spatial-temporal domain,leading to serious losses in the degree of freedom and improvement factor of STAP.The simulation result indicates the availability of the approach.关键词：space-time adaptive processing;scattering;sweeping frequency;space-time covariance matrix;characteristic spectrum107|706|1更新时间：2025-07-16
- 摘要：The performance of the Page Test decreases without the exact knowledge of the transient signal length.A new method independent of the signal length is proposed in this paper.The detector of unmatched signal length of the Page Test is modeled at first.Then the theoretical detection performance and the simulative one of the new method are compared to the general Page Test while detecting the unknown length transient signal.The experiment data on the sea of certain bearing channel after beamforming are exploited to compare these two methods.The result shows that the performance of the method proposed in this paper is more stable than the general Page Test without the exact knowledge of the transient signal length.关键词：Page Test;transient signal detection;unknown signal length;passive sonar detection.188|264|1更新时间：2025-07-16
- 摘要：In order to solve the computation and storage space problems of kernel principal component analysis,which come from the large number of the training samples,this paper presents one-class support vector based sparse kernel principal component analysis (SKPCA).This method can be used in the computation-constrained and space-constrained applications,for example,a small scale hardware platform based image retrieval system,medical assistant diagnosis system,and so on.The method uses the constrained optimization equation to seek the few representative samples,and the few representative samples are used to compute the kernel matrix.The method decreases the computing time and decreases the storage space.So under conditions of the limited training samples,the method is to improve the performance of accuracy and efficiency for hardware computing platform-based image processing.关键词：principal component analysis;kernel method;sparse learning95|231|0更新时间：2025-07-16
- 摘要：The security analysis of block cipher is an important respect in cryptology.Impossible differential analysis and zero-correlation linear cryptanalysis are important methods to evaluate the security of cryptographic algorithms.Based on miss-in-the-middle method and the restrictions on the diffusion layer,this paper gives the zero correlation linear approximations for New-Structure series with SP networks.This paper also presents the consistency between the structures of the differential characteristic with nonzero probability and linear approximation with nonzero correlation coefficient in New-Structure I and New-Structure IV.Moreover,this paper gives the 16/22-round impossible differentials for New-Structure I and III with SP networks respectively.Finally,when the block size and key size are both 128-bit,this paper gives the time complexities and data complexities of the 21/28/22-round impossible differential attack (resp.19/28/22-round multidimensional zero-correlation linear approximation attack) on New-Structure I,III,IV.The results provide theoretical foundations for one cryptographic algorithm based on New-Structure series.关键词：information security;impossible differential cryptanalysis;zero-correlation linear cryptanalysis;New-Structure series271|392|3更新时间：2025-07-16
- 摘要：Considering the colloquial,short text and other characteristics of microblog and deficiencies in research of it,this article proposes a self-adaptive topic tracking method of microblog by user relationship.First of all,during the tracking time window,the candidate tweet set is mapped into feature space.Secondly,aiming at the characteristic of tweet distribution and the purpose of topic tracking,the paper converts the tweets' feature space.Based on this operation,a binary clustering on tweets set can be constructed by improved K-means clustering algorithm.The yielded relative collection is the target model of the current topic.The experiments with the data extracted from Twitter,show that this method can track down the trend of hot topics and the evolution of focuses in real time,and improve the stability of topic tracking in microblog.This method serves well for user recommendation and public opinion analysis.关键词：microblog;topic tracking;self-adaptive;user relationship;polar coordinates;K-means algorithm317|814|3更新时间：2025-07-16
- 摘要：With the development of the integrated circuit(IC) manufacturing technology,very large scale integrated(VLSI) circuits test is faced with the problems of over large test data volume and high test power consumption.This paper presents a low-power multistage test data compression scheme to address these two problems.Firstly,the proposed scheme preprocesses the original test set with the input reduction technology so as to reduce the volume of specified bits;secondly,the scheme compresses test patterns shifted in multi-scan chains according to their compatibilities and uses shorter code to demonstrate compatible test patterns,namely the first stage of compression;thirdly,the low power X-filling is conducted:X-filling for capture power reduction is first conducted for the unspecified bits to keep the capture power under the given threshold and then the remaining unspecified bits are filled for shift power reduction;finally,the proposed scheme further compresses test patterns using modified run-length coding.Experimental results for ISCAS89 benchmark circuits demonstrate that,compared with golomb,FDR,EFDR,9C,BM code,etc.,the proposed scheme achieves better compression rate while reducing both the capture power and the shift power.关键词：test vector compatible;low power test;test data compression;multistage compression263|291|4更新时间：2025-07-16
- 摘要：Aiming at the security problem existing in platform configuration attestation (PCA) of integrity report protocol (IRP),this paper puts forward a PCA based on authorization policy by establishing an authorization restriction between respondent and platform configuration information.The authorization-based PCA prevents the tampering attack before the information of PCA is submitted to the respondent and the middle-man attack after the information of PCA is sent to requester.The proposed PCA holds the correspondence properties and solves the security problems about local and global attacks,which enhances the security of IRP.关键词：platform configuration attestation;correspondence property;authorization restriction108|289|1更新时间：2025-07-16
- 摘要：In order to improve flow-identifying performance,a flow-identifying algorithm for TCP (Transmission Control Protocol) traffic was proposed.This algorithm constructs bidirectional-flow finite state automaton based on TCP communication process and judges flow-termination according to TCP protocol rules and flow states by this automaton.Meanwhile,the algorithm adds filtering mechanism and timeout strategy to identify single-packet flows and abnormal interrupt flows.This algorithm is lower in memory overhead,the total overhead of memory and computing resources than the classic algorithm FT (Fixed Timeout strategy) and the similar representative algorithm TSAT (Two-level Self-Adaptive Timeout).Furthermore,this algorithm is higher than TSAT in accuracy and only loses little accuracy compared to the default accuracy standard.Our algorithm identifies TCP flows based on protocol rules,so it can obtain high identifying accuracy and can save extra flow keeping-time.And our algorithm is especially suitable for situations when the proportion of small flows,medium flows or irregular flows is larger,so it can ensure flow-identifying system to work normally when network anomalies occur,such as worm infection,DDoS attack,and so on.关键词：flow identifying;TCP;finite state automaton;attribute recognition degree;flow timeout3|2|0更新时间：2025-07-16
- 摘要：In three-dimensional(3D) underwater wireless sensor network,the bad environment is easy to cause node invalidation and topology instability.Considering that obstacles and boundary exist in practical water environment,we put forward the fruit fly inspired underwater sensor network deployment algorithm.Firstly,the method regarded connectivity as the constraint condition,and it used foraging behavior of fruit fly to obtain the nodes location.Meanwhile,it added European starling flying features to keep the stability of network topology.Finally,it used obstacle local perceive model to avoid obstacles.The results show that the algorithm can avoid obstacles,further improve coverage and connectivity,and reduce energy consumption.关键词：underwater sensor network;deployment;fruit fly optimization;avoid obstacles3|2|4更新时间：2025-07-16
- 摘要：In order to improve the average throughput performance of user effective data under highway scenario,a distributed channel access mechanism is proposed.The protocol sequence set is reused by road division.According to the characteristic of UI(User Irrepressibility) sequences,a few bits of feedback information are introduced for detecting the channel access order among nodes.Distributed TDMA(Time Division Multiple Access) is proposed for maximizing the throughput performance with a competition zone.The simulation results show that the throughput performance of UI-TDMA mechanism is more superior to classical method in a sparser distributed network or a higher PHY data rate or a larger communication range of node.关键词：hybrid channel access mechanism;protocol sequence;time division multiple access (TDMA);vehicular ad hoc networks (VANET);global navigation satellite systems (GNSS)2|2|1更新时间：2025-07-16
- 摘要：Event recognition is critical to information extraction.To overcome limitations of the exiting event recognition approaches,we proposed an event recognition model based on deep learning (DL-ERM).Firstly,we acquired candidate words through a word segmentation system and classified them into five categories.Then,we selected six recognition feature layers and constructed corresponding feature representation rules to convert words into vector samples.Finally,we employed a deep belief network (DBN) to extract deep semantic features of words,and used a back propagation neural network to identify events.The results of experiments show that the maximum F-measure is 85.17%.Furthermore,we presented a hybrid-supervised DBN,which combines the unsupervised and supervised learning.The novel DBN improves the recognition performance (89.2% F-measure) and effectively controls the training time (increased by 27.50%).关键词：event recognition;deep learning;recognition feature;feature representation;hybrid supervision2|2|8更新时间：2025-07-16
- 摘要：Accounting uneven workload allocation,hardware bounds and communication latency,a performance analytic model is derived based on extended Amdahl's law for multicore processors.The speedup model can be applied as a guide for hardware design as well as a performance prediction model in multicore processors domain.The design space for the specific multicore processors is explored.According to the results,some suggestions about how to design the specific multicore processors,such as the architecture type (homogenous or heterogeneous),the number of cores integrated in the multicore system,the scale of cores to execute computing workload,and the communication area,are provided to the designers.关键词：multicore processors;Amdahl's law;performance model;parallel computing;speedup2|3|1更新时间：2025-07-16
- 摘要：The LSH (Locality Sensitive Hashing) method and its variants represent the state-of-the-art indexing techniques to process ANN (Approximate Nearest Neighbor) searches in a high dimensional data space.Although the existing LSH based techniques can efficiently deal with uniform distributed data,it is noticed from the principle of their design schemes that these techniques cannot handle non-uniform distributed data well.To tackle the above problem,this paper presents a new LSH based technique,called M2LSH (2 Layers Merging LSH),to efficiently process ANN searches on non-uniform distributed data.The key idea is as follows.First,data objects are stored in a hash table with multiple buckets (i.e.,the first layer),each of which corresponds to a combined hash vector used as its hash number.The count of data objects in each hash bucket is recorded.Secondly,using the hash functions for a second layer hash table,the bucket numbers from the first layer are projected into a one-dimensional space.In this space,some adjacent hash buckets from the first layer are merged so as to make the data objects uniformly distributed in the merged buckets at the second layer.Therefore,the M2LSH can not only improve the searching efficiency but also increase the accuracy of the search results.This paper also provides a detailed theoretical accuracy analysis for the M2LSH technique.Experiments using synthetic and real data show that the theoretical estimates are quite accurate,and the proposed M2LSH technique can efficiently process ANN searches with low false positive and negative rates.关键词：approximate nearest neighbor (ANN);k-nearest neighbor (KNN) search;locality sensitive hashing (LSH);high dimensionality2|2|4更新时间：2025-07-16
- 摘要：To cope with eavesdropping in both the cellular link and the D2D(Device-to-Device) link of relay-aided D2D system,this paper proposes a jamming based secure transmission method.Firstly,the transmission procedures of both the cellular link and the D2D link are modeled.Secondly,an artificial noise (AN) is added into the signal of the base station (BS) and the relay to interfere the eavesdropper.Finally,a joint optimization scheme for the power allocation of BS and the power control of D2D is introduced to maximize the system secrecy rate.Simulation results show that the system ergodic secrecy rate is increased by 1.5bit/s/Hz,which is great improvement compared with the scheme based on SVD and ZF.关键词：D2D;secure transmission method;artificial noise;secrecy rate2|2|2更新时间：2025-07-16
- 摘要：The fast-moving characteristic of VANET(Vehiche Ad-hoc NETwork) leads to a high complexity of network structure that the conventional methodology of network cannot figure out.The solution proposed was based on the complex networks theory since its applicability is straightforward for this high complexity of VANET.And a mobility model was also proposed based on the process of network construction of VANET.The combination of the complex networks theory and the mobility model can be used to analyze the degree distribution,robustness,and the rate of connection change of VANET.Meanwhile,the method be simulated and validated.The results show that the proposed mobility model can represent the process of network construction of VANET,and the complex networks theory is very effective in its property analysis.关键词：VANET;mobility model;degree distribution;robustness;link change rate2|3|2更新时间：2025-07-16
- 摘要：In the previous linear cryptanalysis of 288-round Trivium,it is problematic to treat the key as a random and changing value in the process of analysis.In this way the attackers actually cannot attack the cipher with the inaccurate linear bias.For the problem above,we present the linear cryptanalysis of 288-round Trivium afresh under chosen initialization vector (IV) condition.Because the key bits are fixed,the nonlinear term which consists of key bits should be constant and does not produce a linear bias,and we find a linear approximation with the linear bias of 1.9E-6 on the condition that 10 bits of the IV are fixed.关键词：cryptanalysis;linear cryptanalysis;Trivium;linear bias2|2|0更新时间：2025-07-16
- 摘要：When the dimensionality of the semantic attributes is limited,it is difficult for attribute-based zero-shot image classifiers to distinguish the objects with similar attributes.Aiming at the limitation of describing objects with semantic attributes,an improved direct attribute prediction(DAP) model for zero-shot image classifying based on hybrid attribute(HA) is proposed,which is called HA-DAP.At first,we carry out the sparse coding on the low-level features to obtain the non-semantic attributes that are used to assist the existing semantic attributes.Then,we take the hybrid attributes including the learned non-semantic attributes and the manually specified semantic attributes as the mid-layer of DAP model and use the idea of attribute prediction to train the hybrid attribute-based classifier.At last,according to the predicted hybrid attributes and the relationship between the attributes and classes,we can recognize the class label for the testing sample.Experimental results on the OSR,Pub Fig and Shoes datasets show that,the HA-DAP outperforms the DAP in the classification performance,i.e.,when compared with the DAP,the proposed HA-DAP yields much higher zero-shot image classification accuracy and AUC value.关键词：zero-shot image classification;hybrid attribute;semantic attribute;non-semantic attribute;sparse auto-encoding3|3|5更新时间：2025-07-16
- 摘要：Constacyclic codes over finite fields are a class of important linear codes.This class of codes has rich algebra structure and its encoding and decoding circuits can be easily performed.Constacyclic codes over finite fields have many applications in information transmission.In this paper,the structure of Hermitian self-orthogonal constacyclic codes over a class of finite fields of any length is studied.By using generator polynomial,the condition for the existence of Hermitian self-orthogonal constacyclic codes over this class of finite fields is explored and the enumeration formula of such codes is determined.Further,Hermitian self-orthogonal constacyclic codes over this class finite fields are applied to construct some optimal quantum codes.关键词：constacyclic code;Hermitian self-orthogonal code;generator polynomial;quantum code2|2|1更新时间：2025-07-16
- 摘要：Firmware is the soul of an embedded system,and disassembly is a necessary step to understand the operational mechanism or detect the vulnerabilities of the firmware.When disassembling a firmware,it should first determine the processor type of running environment and the image base of firmware.In general,the processor type can be got by tearing down the device or consulting the product manual.However,at present there is still no automated tool that can be used to obtain the image base of firmware.Since the processors of majority embedded systems are ARM architecture,in this paper we focus on the firmwares in ARM and propose an automated method to determine the base address.Firstly,by studying the storage rule and loading mode of the string we present two algorithms to calculate the string offset and the string address loaded by LDR instruction.Then with these information,we proposed a DBMAS (Determining image Base by Matching Addresses of Strings) algorithm to determine the image base.Experimental results indicate the proposed method can successfully determine the image base of firmware that uses the LDR instruction to load string address.关键词：image base;firmware;ARM;disassemble6|2|1更新时间：2025-07-16
- 摘要：Magnetic resonance elastography (MRE) is emerging to virtually palpate human body and visualize tissue elasticity.Although MRE receives more and more attention in clinic,the study is limited due to the inaccessibility and expensiveness of magnetic resonance scanning.A numerical model is thus proposed by analyzing tissue elasticity and the forced movement differential equation.The finite element method (FEM) is introduced to resolve this numerical model of MRE.Its performance is validated with different models of tissue structure and elasticity composition.The results of quantitative experiments confirm that the new model is effective to promote numerical MRE study.关键词：elastic wave;magnetic resonance elastography;soft tissue;tissue elasticity;numerical simulation2|2|2更新时间：2025-07-16
- 摘要：The characteristics of long reach and wide coverage in time and wavelength division multiplexed passive optical network(TWDM-PON) increase the round trip time,resulting in the severe deterioration of the delay performance of high priority traffic.This paper proposes a hybrid resource scheduling algorithm with traffic differentiation to solve this issue.Firstly,the wavelengths of ONU(Optical Network Unit) groups are realtimely adjusted to achieve resource sharing in accordance with the network load,and traffic sub-cycles are dynamically divided for the purpose of differentiated traffic.Furthermore,we respectively exploit the online and offline scheduling to fill the wavelength voids and ensure the efficiency of resources scheduling.Finally,the simulation results show that the proposed algorithm can satisfy the delay requirements of different priority traffic,guarantee the quality of service and improve the channel utilization ratio.关键词：TWDM-PON;hybrid resource scheduling;traffic differentiation;Quality of Service2|3|3更新时间：2025-07-16
- 摘要：To improve the capability of detecting weak moving target with unknown statistical feature,a kind of track-before-detect (TBD) algorithm implemented by cost-reference particle filter (CRPF) is proposed (CRPF-TBD).Firstly,a discrete variable mimicking the existence and absence of a target is added to the state vector of CRPF.Particularly,besides transform probability matrix,the transformation of the discrete variables in the CRPF-TBD also depends on the correlative coefficient of successive measurements.Secondly,the existence probability at each frame is calculated from the output discrete variables.Finally,a binary test statistic is constructed from the existence probabilities.Target is declared to be present if the test statistic exceeds a given threshold.Simulation experiments of over-the-horizon radar (OTHR) target detection show that,in the case of given statistical feature,the detection performance of the proposed method is comparable to that of the traditional particle filter (PF) based likelihood ratio algorithm and existence probability detection method,and improved by more than 2dB when the statistical feature is unknown.The proposed method could be applied to surveillance in complex environment,such as radar and sonar.关键词：cost-reference particle filter (CRPF);track-before-detect (TBD);existence probability;particle filter2|2|0更新时间：2025-07-16
- 摘要：This paper presents a cyclostationary difference-based anti-jamming method by blindly extracting direct sequence spread spectrum signal.Aiming at approximate independence among source signals,an anti-jamming model based on blind source separation is established for direct sequence spread spectrum communication.And then,by using typical extreme points of cyclic autocorrelation function,a characteristic parameter called second-order cyclic difference degree is defined based on cyclostationary difference to distinguish between direct sequence spread spectrum signal and jamming.Finally pattern recognition is used to extract expected signal and suppress jamming by comparing the values of characteristic parameter,so as to achieve the purpose of anti-jamming.Simulation results show that,when the NSNR (Normalized Signal to Noise Ratio) is 9 dB and the SJR (Signal to Jamming Ratio) is -40 dB,the direct de-spreading/demodulation signal achieves the bit error rate (BER) of nearly IE-0.3,while the proposed algorithm achieves the bit error rate of as low as IE-3,which can extract the direct spread signal from the strong jamming effectively.关键词：barrage jamming;sweep-spot jamming;cyclostationary;blind source separation;anti-jamming2|2|2更新时间：2025-07-16
- 摘要：In order to predict the interference pulse entering the equipment in conducted susceptibility testing,a SPICE(Simulation Program with Integrated Circuit Emphasis) model of pulsed current injection(PCI) is developed.Firstly,after the whole circuit is decomposed into various modules,circuit equations are derived from the measurement data with the method of transmission matrix calculation.Then each module is expressed by SPICE model.At last,the complete model is assembled with subcircuit models.The modeling result is identical to the measurement in validation experiment.The SPICE model can be used to design and optimize PCI tests.关键词：pulsed current injection;inductive coupling;current injection probe;GFREQ model3|2|6更新时间：2025-07-16
- 摘要：Based on the importance of the statement,a novel method of selecting mutation object is proposed so as to reduce mutants.In this method,three factors that reflect the importance of an object are given,and then an index system of evaluating the importance of an object is established based on the importance of these factors.Finally,statements with high importance are selected as the objects to be mutated according to the values of these indexes.The proposed method is applied to test eight benchmark or industrial programs,and the experimental results suggest that the proposed method significantly improves the efficiency of mutation testing with high mutation sufficiency.关键词：software testing;mutation testing;mutant reduction;test object selection;important statement2|2|0更新时间：2025-07-16
- 摘要：The existing studies on maritime wireless channel environment at VHF/UHF(Very High Frequency/Vltra High Frquency) Bands lack experimental data in aspects of radio propagation and background noise.Therefore,we carried out a series of maritime wireless communication experiments to estimate adaptivity of the existing radio propagation models to within-the-horizon path,transhorizon path and just critical path.Moreover,we presented a method to analyse the maritime frequency-selective channel quantificationally from space-time perspective,and defined concepts of space-time frequency migration and declination.The results can be applied to maritime radio propagation modelling and abnormal phenomena analysing.关键词：maritime radio propagation;VHF and UHF;wireless channel;space-time frequency selectivity;evaporation duct2|2|1更新时间：2025-07-16
- 摘要：Concentrating on the data sparsity problem and the new user cold-start problem faced by traditional collaborative filtering algorithm in mobile recommender system,an approach named CSMSR (Context-similarity and Social-network based Mobile Service Recommendation) is proposed.The approach integrates mobile users' context information and social network information into collaborative filtering recommendation process.Firstly,it imports the user-based context similarities into the personalized service recommendation process.Secondly,it searches the corresponding nearest neighbors for each mobile user according to the given mobile users' ratings and the mining social network.Finally,it predicts unknown mobile users' preferences and generates recommendations.The experimental results show that CSMSR outperforms the existing service recommendation methods,such as TNCF,SRMTC and CF-DNC in terms of MAE (Mean Absolute Error) and P@N,and it performs well in finding out the interested services of users and enhancing the user experience.关键词：mobile service recommendation;context;similarity measure;social network;collaborative filtering;data sparsity;cold-start problem2|2|9更新时间：2025-07-16
- 摘要：This paper introduces our practical application of the smart and cooperative network paradigm to industrial wireless sensor network (IWSN).An architecture Smart-IWSN is proposed for researchers and developers.Smart-IWSN platform provides more controllable network resources for complicated industrial applications,which could satisfy network performance requirements for industrial applications and reduce the time and cost for research and application of IWSN.Smart-IWSN has been applied to welder machine monitoring and control application,which can solve the problem of multitask parallel communication in harsh industrial environment.关键词：smart and cooperative network;industrial wireless sensor network2|2|14更新时间：2025-07-16
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