最新刊期
卷 43 ， 期 5 ， 2015
- 摘要：The pervasive deployment of wireless smart devices stimulates the development of ad hoc networks.Such networks,also referred as opportunistic networks,are intermittently connected and represent a paradigm shift of forwarding data in an ad hoc manner.A recent trend is looking at social relationships,inferred from the social nature of human mobility,to bring messages close to a destination.We addressed this challenge by presenting a social context-aware opportunistic routing (SCOR).In this novel protocol,social context information of the network was exploited to predict the mobility patterns of nodes based on the back-propagation neural networks model.The routing scheme considered both the spatial and the temporal dimensions.If the recipient was present in the same connected region of the network as the sender,the message was delivered by synchronous method,or else the message was delivered by asynchronous method.The evaluation analysis and the simulation results indicate that for the social context-based routing algorithms in opportunistic networks,SCOR solution outperforms other routing solutions due to its ability to maximize the delivery ratio and to minimize the network overhead.关键词：social relationship;context-aware;neural networks;opportunistic routing2|2189|5更新时间：2025-07-16
- 摘要：In model-based diagnosis,minimal hitting sets problem is an important topic of artificial intelligence,and a lot of practical problems can be converted into it,such as teachers and curricula problem,minimum covering sets problem,etc.By studying the characteristics of minimal hitting sets,combining with the original PSO algorithm of computing minimal hitting sets,this paper proposes a new algorithm to guide the minimum hitting sets computation:introducing a learning mechanism to cut down some search of the no-solution space;adding a flipping strategy to accelerate some solving of solution space.Experimental results show a significant improvement of this new algorithm in computing minimal hitting sets.关键词：minimal hitting sets;characteristics;learning mechanism;flipping strategy2|1236|9更新时间：2025-07-16
- 摘要：Clutter spectrum in space-time domain is jointly recovered based on subspace-augmented multiple signal classification theory (SA-MUSIC).The performance of space-time adaptive processing (STAP) under small sample size is greatly improved.Firstly,the sparse nature of clutter in space time domain is analyzed using the space-time steering vector correlation model,and the reason of using few space-time steering vectors to represent the whole clutter subspace is given.Secondly,an algorithm named as SA-MUSIC-STAP is proposed to estimate the clutter covariance matrix with much less training samples,then the clutter is effectively suppressed by the new algorithm.Simulation results verified the effectiveness of SA-MUSIC-STAP.关键词：airborne radar;space-time adaptive processing;clutter suppression;joint sparse recovery;multiple measurement vector3|1516|6更新时间：2025-07-16
- 摘要：Efficient object contour segment is a critical problem to describe the local features of objects.In order to solve the improper contour segments obtained by the existing recognition methods,a hierarchical description algorithm of contour description is proposed.Firstly,the whole contour is divided into several contour segments by the corners on the contour.Then the valuation scale is put forward via the distribution of contour segments.Thirdly,combine these contour segments into several contour feature segments according to the valuation scale.Finally,the similarity of different contour feature segments,in combination with their lengths,is jointly used to get the best recognized results.The experimental results of MPEG-7 database indicate that this algorithm has great advantage over recently published algorithms,especially for the objects with partial occlusion.Hence,this novel algorithm satisfies the requirements of accuracy,robust and anti-occlusion in object recognition and shape retrieval.关键词：contour description;object recognition;valuation scale;part occlusion2|1698|7更新时间：2025-07-16
- 摘要：A digital hardware implementation of Tangent Sigmoid (Tan-Sig) activation function based on sigma-delta modulated bit-streams is proposed.Through the change of feedback coefficient in the framework of traditional sigma-delta modulator,a new limiting amplifier modulator (LAM) is fabricated,and the function approximation to Tan-Sig was achieved by the combination of several LAMs with different coefficients.Meanwhile,the bit-stream neurons with Tan-Sig activation function and the whole feed-forward artificial neural networks are implemented on field programmable gate array (FPGA).And the 3-D space classification problem in Cartesian coordinate system was solved by the neural networks presented.2|1454|1更新时间：2025-07-16
- 摘要：At run time,a large number of program branching information is leaked.Branching information is the binary representation of program internal logic.Symbolic execution could automatically collect and reason about the leaked branch information,which could be used for reverse engineering and weaken the strength of code obfuscation.Hash function can effectively safeguard equal branch conditions,but it can't be used to protect branching information containing unequal trigger conditions,such as greater than or less than.In this paper,a new branch obfuscation approach combining prefix-preserving algorithm and hash function,which extends the protection scope of hash function.The strength and resilience of the branch obfuscation are discussed.This branch obfuscation approach has been tested on 7 programs from the SPECint-2006 benchmark suite,and the experimental results show that this approach could effectively mitigate branch information leaking,yet practical in terms of performance.关键词：code obfuscation;symbolic execution;Hash function;prefix-preserving encryption3|1803|4更新时间：2025-07-16
- 摘要：By deploying Peer-to-Peer (P2P) caches at the edge of access ISPs,cross-ISP P2P traffic can be reduced.The problem is how to design an optimal cache capacity? Up to now,no optimal P2P cache capacity design method has been proposed yet.In this paper,an optimal P2P cache capacity design method is proposed based on the storage versus bandwidth cost tradeoff.In order to minimize the total traffic cost of access ISPs,the cache capacity design problem is formulated into an integer programming problem whose objective function is piecewise continuous.The formula of optimal cache capacity can be derived through theoretical derivation.Experimental results suggest that compared with several simple design rules including No Cache,Median and “20-80 Rule”,ISPs can achieve significant cost saving using our method.For example,compared with "20-80 Rule" that is most commonly used by ISPs nowadays,the cost saving can be as much as 7.5%.关键词：P2P(Peer-to-Peer)caching technology;ISP (Internet service provider)network;cache deployment;capacity design2|1298|4更新时间：2025-07-16
- 摘要：In standard cultural algorithm,the influence function guides the evolution only by a single layer belief space,which may invalidate the structure of cultural algorithm and lead to poor global optimization and instability.Therefore,a cultural algorithm based on multi-layer belief space is proposed.The algorithm increases the validity of knowledge and at the same time provides the optimal mode for the evolution of main population space by managing multilayer belief spaces hierarchically.And adjust the fusion mechanism of the multilayer belief spaces adaptively according to the population dispersion so that it can keep the population diversity in the early evolution and accelerate population convergence in the late evolution.Aiming at benchmark functions,comparing with some other similar algorithms,the proposed algorithm shows better optimization performance in the precision of the solution,stability and global convergence.关键词：cultural algorithm;multi-layer belief space;decentralized management;population dispersion;fusion mechanism2|1231|3更新时间：2025-07-16
- 摘要：In order to decrease the interference to the primary user (PU) caused by the secondary user (SU) in cognitive radio,a spectrum sensing method is proposed to cooperatively detect the PU through multi-slot energy sensing of the SU.Each transmission frame was divided into several time slots,and the SU sensed the PU at the beginning of each time slot.The SU could improve the performance of detecting PU through combining the multi-slot sensing results.In order to maximize the SU's spectrum efficiency,the PU state was built as a two-dimensional Markov random process,and according to this process,the single-slot sensing time was optimized.The simulation results show that compared to the "listen-before-transmit" spectrum sensing method proposed by Liang,the proposed method reduces the interference probability of 28% by only sacrificing the spectrum efficiency of 14%,and with the increase of the signal-to-noise ratio (SNR),the maximal spectrum efficiency of the proposed method gradually approaches that of the "listen-before-transmit" spectrum sensing method.关键词：cognitive radio;cooperative spectrum sensing;spectrum efficiency;interference probability2|1236|4更新时间：2025-07-16
- 摘要：This paper studies the variance characteristics of chaotic signal in different conditions and puts forward an adaptive denoising algorithm on account of EMD decomposition layers,by using the Empirical Mode Decomposition (EMD).The arithmetic can adaptively select the IMF layer which needs to be processed,based on the relationship between the maximum variance corresponding layers and the total number of decomposition layers of intrinsic mode function (IMF),and it also can make intergrated denosing by making use of the lifting wavelet's advantages in the field of updating and predicting.It carried out the experimental study,based on the chaotic background noise from Lorenz and Chen System(adding 10%-100% white gaussian noise) and the measured IPIX radar data.The result shows that:under varying degrees of low noise (≤30%),it decreases the error of mean square by at least 30% compared with the methods such as traditional wavelet threshold denoising,and the signal to noise ratio has increased by 1.5db-3.5db,and can effectively reduce the sea clutter noise to increase the detection effect under the background of chaos.关键词：empirical mode decomposition;chaos;variance characteristics;lifting wavelet;adaptive denoising algorithm2|1467|8更新时间：2025-07-16
- 摘要：Physical Unclonable Functions (PUF),as a kind of innovative secure circuits,extract key relying upon the intrinsic process variations in silicon devices.This paper proposes a scheme of highly robust PUF.First,we analyze the properties of the MOSFET working at the point of Zero Temperature Coefficient.And then we determine the structure and the optimal gate voltage of PUF by combining the approaches that improve the robustness of PUF circuits.All of which lead to the goal of making the keys stable and reliable at last.This design is implemented in TSMC 65nm CMOS technology and the layout area occupies 14.89μm×12.14μm. The simulation results show that the reliability of PUF is not less than 96%,which is better than other PUF circuits.关键词：physical unclonable functions;zero temperature coefficient;robustness;circuit design2|1422|4更新时间：2025-07-16
- 摘要：To recover the position of occlusion,an occlusion recovery method based on orthogonal complement subspace is presented.Two images are combined into a group and the occlusions in the group are removed.Then,the position of occlusion is linearly obtained,based on the fact that the sum of orthogonal complement subspaces spanned by all the image groups equals to the one spanned by the 3D space structure points.Being linearly,the method for occlusion recovery overcomes the shortcoming that some existing iteration methods need a good original value.At the same time,all the images and all the image points are treated uniformly.The experiments with both simulate and real data show that the method is efficient,robust and has small re-projection errors.关键词：occlusions;orthogonal complement subspaces;re-projection2|1091|3更新时间：2025-07-16
- 摘要：Convergence rate estimation of clonal selection algorithm is a difficult problem and it is still in the initial stage.The convergence rate of elitist clonal selection algorithm is studied in this paper.The best individual transition probability matrix is derived from the best individual directional transition probability in algorithm populations.It is difficult to calculate the matrix due to the large algorithm population size in practical applications.On the basis of certain conditions,the best individual transition probability matrix is constructed to a matrix norm and a simpler and more effective new average convergence rate estimation method of a class of clonal selection algorithm is proposed.The simulation experiments of different elitist clonal selection algorithms show the validity of the estimation method.关键词：clonal selection algorithm;elitist strategy;average convergence rate;transition probability;matrix norm2|1131|0更新时间：2025-07-16
- 摘要：Compressed sensing is a novel theory for signal processing which breaks through the sampling limitation based on traditional Shannon sampling theory,and makes it into reality that one can efficiently acquire and exactly reconstruct a signal using the prior knowledge that it is sparse or compressible.In reality,however,some signals exhibit additional structures,the typical example is the signal which is called block-sparse signal,i.e.,the non-zero coefficients appear in a few fixed blocks.In order to tackle such block-sparse signal,in this paper we investigate the iterative reweighed least squares algorithm for block-sparse compressed sensing.The error estimation and local convergence analysis have been established.We simultaneously demonstrate the effectiveness of the iterative reweighed least squares algorithm (IRLS) for block-sparse compressed sensing by simulation results.关键词：compressed sensing;iterative reweighed least squares algorithm;block-sparse signals;error estimation;local convergence2|1870|2更新时间：2025-07-16
- 摘要：Natural gradient algorithm occupies an important position in blind source separation due to its good separation performance,but when the algorithm is based on a fixed-step size,a good balance will impossibly be achieved between the convergence rate and steady-state error.This article drew PID (Proportion Integration Differentiation) algorithm of automation control as a reference and proposed an algorithms in variable-step learning rate closely integrated with the state of separation.Due to the fact the cumulative amount of the signal kurtosis was an intrinsic value after the complete separation,there arose a gradually decreasing error value between the cumulative amount of the signal kurtosis of the separation process and the inherent value.The exponential function value of e in the algorithm was applied to reflect the error value.Then the error was used to constitute proportional differential variable-step algorithm,among which the initial value of the step was equivalent to proportional value of the error control,and the differential term of the error gained the adjusted values in acceleration.The simulation results show that corresponding to a maximum and a minimum of step initial value,the number of iterations of the algorithm in two times was lower than that of iterations with fixed-step algorithm,and the difference between the two iterations was about 10 to 40 times for signals of different type,however,the steady-state error of the two algorithms was the same.关键词：blind signal separation;kurtosis cumulative;proportion differential control;variable-step size in learning rate2|1198|1更新时间：2025-07-16
- 摘要：Components decomposition of Tibetan words is the basic work of Tibetan information processing,it provides significant theoretical value and has wide application perspective.Since the complexity and variety of components of Tibetan words,this paper studies the process of components decomposition of Tibetan words by analyzing the grammars and the structure of Tibetan words,gives a component decomposition algorithm and judgment theorems about decomposition based on the one-to-one relationship between each output character and its state transition of Mealy machine,then verify the validity of the algorithm by a component decomposition system based on Mealy machine.关键词：Tibetan information processing;Mealy automata;components;component decomposition2|910|3更新时间：2025-07-16
- 摘要：Addressing the wireless digital communication system,a sufficient condition to ensure the physical-layer security transmission is derived from the viewpoint of information theory,and a space hopping secure transmission method is proposed,which can mask the characteristic of finite alphabets.First,since the multi-antenna eavesdropper in the finite-alphabet-input system possesses the architecture of Discrete Noisy Lossless Channel (DNLC),it can reconstruct the secret signal and invalidate the artificial noise method.As a result,destroying the eavesdropper's DNLC architecture becomes a sufficient condition for ensuring the security of system transmission.Then,utilizing the diversity and uniqueness of wireless channel characteristics,a space hopping secure transmission method based on the Multiple Input Multiple Output (MIMO) system is proposed.It switches receiver/transmitter antennas and transmits spatial scrambling during the information transmission,which can mask the finite alphabet characteristic of the secret signal and destroy the eavesdropper's DNLC architecture.Finally,theoretical analysis and simulation results demonstrate the efficacy of the secure method.关键词：wireless physical-layer security;finite alphabet;space hopping;discrete noisy noiseless channel (DNLC);multiple input multiple output multiple-antenna eavesdropper (MIMOME)2|1101|0更新时间：2025-07-16
- 摘要：Artificial bee colony (ABC) algorithm is a new global stochastic optimization algorithm,which mimics the intelligent behavior of honeybee swarms.It has been used to solve various optimization problems successfully.In order to further improve the performance of artificial bee colony algorithm,a mind evolutionary artificial bee colony algorithm (MEABC) based on the idea of mind evolutionary is proposed.Two strategies based on opposition learning and dimension updating are applied to MEABC algorithm,and the convergence of the MEABC algorithm is analyzed.Experimental results on four benchmark functions show that the MEABC algorithm can effectively avoid the premature convergence,greatly enhance the global optimization ability and improve the convergence speed.关键词：global optimization;artificial bee colony;mind evolutionary algorithm;convergence2|1138|6更新时间：2025-07-16
- 摘要：To facilitate traffic understanding,planning and management optimization,we present a new spectral clustering method(TSSC) for big trajectory data mining based on latent semantic correlation.First,a matrix model is proposed to represent vehicle trajectories and the underlying road network with a grid-vehicle matrix,which is then transformed to a low-dimensional semantic subspace with random projection.Second,through matrix decomposition we extract hidden characteristics of the mass trajectory data and construct a similarity matrix for road network cells.Third,we adopt and implement a fast spectral clustering method to discover road network clusters based on the similarity matrix in the semantic space.Finally,we evaluate our approach with a large trajectory data set collected by the Fujian Communications Department,which has 19,719 vehicles and a total mileage of more than 14 million kilometers.Experiment results show that the approach can efficiently cluster the road network with traffic context semantic information derived from massive trajectory data.The approach is capable to discover inherent characteristics of complex road networks and provide insights for traffic planning and management optimization.关键词：traffic trajectory;big data;data mining;semantic space;spectral clustering2|3654|14更新时间：2025-07-16
- 摘要：In the wireless sensor networks,the geographic routing algorithms use the perimeter routing to bypass the routing voids.Usually,the nodes around the voids have heavier workload and die much sooner than the others.In order to achieve load balancing,this paper presents an energy-aware geographic routing algorithm SIENGR.SIENGR divides the initial energy of sensor nodes into 3 energy zones,and identifies them by energy signals.SIENGR uses boundary nodes' all planar neighbors to transmit the data in perimeter routing,by taking the energy signals into account.The generated routing is able to keep away from the void's boundary nodes which have less energy.Our simulation results verified SIENGR algorithm's performance in aspect of networks' lifetime,load balancing and packet delivery.关键词：Wireless sensor networks;routing void;load balancing;energy hole;perimeter routing;planar neighbor2|1118|4更新时间：2025-07-16
- 摘要：Focusing on Internet's emerging paradigm of ubiquitous content sharing,this paper emphasizes on a physically revolutionary and dual-structural approach to the future Internet architecture,which insists on complementing the current Internet architecture with a secondary structure,the broadcast-storage network.By analyzing the concepts,features and key mechanisms of the broadcast-storage network,a general architecture model of broadcast-storage network and its mathematical description are presented.Based on these foundations,some principal realization patterns of the broadcast-storage network architecture are addressed and discussed,including Standard Pattern,Relay Pattern,Consolidation Pattern and UCL Only Pattern.Findings of this paper provide theoretical supports for further study on the strict definition and specification of the broadcast-storage network architecture.关键词：future Internet;broadcast-storage network;content-centric;realization pattern;uniform content label2|1485|5更新时间：2025-07-16
- 摘要：Performance of the networked control system is affected by the sampling period.For the networked control system with multi loop,according to the system contpol loop error and error rate,dynamic weights are calculated by using fuzzy inferential for each control loop,new network utilization is predicted based on the current network status.Then ARIMA algorithm is used to predict the packet transmission time.Finally,under the conditions of the network bandwidth is limited,fuzzy dynamic weight coefficient,network utilization,packet transmission time is used for constantly changing sampling period of the system control loop,to optimize the performance of networked control system.True Time toolbox simulation result demonstrates the effectiveness of this method.关键词：networked control system;scheduling;variable sampling period;fuzzy2|1259|3更新时间：2025-07-16
- 摘要：The optimal software as a service (SaaS) selection based on Quality of Service (QoS) is still challenging because user rating with fuzziness and randomness makes QoS uncertain and decision-making hard.This paper presents a SaaS decision-making method based on cloud model (SDM_CM) to solve the above difficulties for the first time.It includes two main steps:(1) Converting the rating QoS criteria to the cloud model QoS criteria by using the backward QoS cloud generator.(2) Proposing a multiple attribute decision-making algorithm based on cloud model,which draws on the effective and common multiple attribute decision-making algorithm (technique for order preference by similarity to an ideal solution,TOPSIS).The last,a set of experiments demonstrate the benefits and effectiveness of our approach.关键词：cloud model;software as a service (SaaS);user rating;uncertain;technique for order preference by similarity to an ideal solution (TOPSIS)2|1451|6更新时间：2025-07-16
- 摘要：In information network,different sources publish facts with different degrees of credibility and accuracy.To predict the truth values of the facts,several fact-finder algorithms are suggested which iteratively compute the trustworthiness of an information sourceand the accuracy of the facts it provides.However they ignore a great deal of relevant background and contextual information.In this paper,we proposed a novel maximum entropy weighted method to processing trust analysis,allowing us to elegantly incorporate knowledge such as the attributes of the objects and the implications of the sources.Experiments demonstrate that our algorithmsignificantly improves performance over existing.关键词：information gain;maximum entropy;trust analysis;clustering2|1492|10更新时间：2025-07-16
- 摘要：Distributed flow control is a key issue in wireless sensor network design to achieve good network performance.This paper presents a node energy and link capacity constrained flow control optimization model for distributed flow control in wireless sensor networks.Since subgradient-based dual-decomposition method suffers from slow convergence rate and sensitivity in step-size choosing,this paper adopts matrix-splitting based distributed Newton algorithm to maximize the network utility.The proposed algorithm can achieve quadratic convergence rate while requiring almost the same communication overhead as the subgradient-based dual-decomposition algorithm.Moreover,it is shown by simulations that the proposed algorithm has a much better convegence performance than the subgradient-based dual-decomposition algorithm.关键词：wireless sensor networks;matrix splitting;distributed Newton method;network utility2|1207|0更新时间：2025-07-16
- 摘要：A novel high-throughput DNA sequence compression method based on codebook index transformation (CITD) is proposed.In CITD,we used the codebook index transformation (CIT) model,to substitute the traditional represatation of codebook indexes by the quaternary values which are expressed by the four standard base characters,and adopted a simple encoding method to distinguish the replaced and non-replaced substring,and subsequently determined whether need to use the Burrow Wheeler Transformation (BWT) according to the value of information entropy,finally used move to front (MTF) transformation and Huffman entropy coding to compress the data.Experimental results on several sequencing data sets demonstrate better performance of CITD than the high-throughput DNA sequence compression algorithms cited in this paper,in most cases.关键词：high-throughput DNA sequence;codebook index transformation(CIT)model;burrow wheeler transfarmation(BWT);move to front(MTF);information entropy;data compression algorithm2|1593|0更新时间：2025-07-16
- 摘要：Minimum attribute reduction (MAR) problem in the context of rough set theory is an NP-hard nonlinearly constrained combinatorial (binary) optimization problem.In this paper,a new combinatorial artificial bee colony (ABC) algorithm is presented for solving the MAR problem.Mutation operation based search schemes are introduced for employed bees,onlooker bees and scout bees.Two different metrics related to attribute subsets are used to generate candidate neighboring food sources.Different local search strategies between an employed bee and its recruited onlooker bees allow for a more diversified neighboring search around a current food source.Moreover,the information of the so-far best solution is exploited in various ways by employed bees,onlookers and scouts,respectively.Performance comparisons with existing best performing meta-heuristic approaches for the MAR problem were carried out on a number of UCI data sets.In addition,a standard statistical t-test is used for evaluation purpose.The experimental results show that our combinatorial ABC approach compares favorably with all the other approaches in terms of solution quality.The proposed combinatorial ABC algorithm is thus efficient and well suited for solving the MAR problem.关键词：combinatorial artificial bee colony algorithrn;minimum attribute reduction;rough sets;meta-heuristic approach;local search schemes2|1326|6更新时间：2025-07-16
- 摘要：A highly integrated CMOS transceiver was presented for 2.4GHz unlicensed ISM (Industrial,Scientific and Medical) band compatible to the IEEE 802.15.4 Standard.Low-IF topology was adopted in the receiver for low power consumption and high sensitivity while direct up-conversion in transmitter for low complexity.The transceiver chip has been fabricated in a 0.18μm 1P4M CMOS (Complementary Metal Oxide Semiconductor) technology with MIM (Metal-Insulator-Metal) capacitors and supplied by a single 1.8V.The experimental results show that the receiver achieves a sensitivity of -97dBm for PER(Packet Error Rate) of 1% and the transmitter provides a max power output of +3dBm into 100Ω differential antenna port.This transceiver dissipates 17mA in receive mode and 19mA in transmit mode and occupies an area of 3.3mm×2.8mm.关键词：CMOS integrated circuits;ZigBee;IEEE802.15.4;radio transceiver2|1954|1更新时间：2025-07-16
- 摘要：The scanning electron microscopic contrast mechanism and secondary electron (SE) current characteristics are clarified for imaging a buried microstructure of the dielectric,by applying a self-consistent numerical model that incorporating electron scattering,trapping and transport.Simulation results show that,the trapped charges by trench interface can affect the space charges,spaces field and consequently SE current characteristics.With irradiation,the local electric field intensifies above the surface along z direction increase.Therefore,more SEs can return to the surface and result in the dark image.The image results in contrast exhibits the maximum value with the beam energy,but increases with the beam current.The simulation results are in good agreement with the experimental ones.关键词：dielectrics;buried structure;scanning electron microscopy;secondary electron current2|1191|1更新时间：2025-07-16
- 摘要：To deal with the key exposure problem in aggregate signature,this paper extends the parallel key-insulated mechanism to aggregate signatures and introduces the primitive of parallel key-insulated aggregate signature.On the basis of formalized definitions and security notions,we propose the first parallel key-insulated aggregate signature scheme and demonstrate that the proposed scheme is provably secure in the random oracle model.The proposed scheme satisfies key-insulated security,strong key-insulated security and secure key-updates.Especially our scheme is high-efficiency in verifications.Two introduced helpers can alternately help users to update the private keys,which strengthen the system's ability to resist the key compromise.关键词：key-insulation;parallelism;aggregate signature;random oracle model3|1085|4更新时间：2025-07-16
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