15 January 2017, Volume 43 Issue 1
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Computer Engineering. 2017, 43(1): 1-7.The virtual machines which are I/O intensive need to communicate with each other frequently.In order to solve the problems of low efficiency and big latency in inter-domain communication of virtual machines,an inter-domain communiaction optimization method between driver domain and user domain based on Double Ring Buffer(DRB) is proposed.Two ring buffers in user domain are built to be shared with a driver domain,and the access rights of the driver domain is controlled by the virtual machines monitor according to I/O task tables,which reduces the overhead of processor mode switching and memory mapping.Experimental results show that the inter-domain communication mechanism after using the optimization method has higher throughput and lower delay compared with original inter-domain virtual machine communication mechanism,and it greatly improves the inter-domain communication performance of the user domain and drive domain.
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Computer Engineering. 2017, 43(1): 8-12.To solve the problem that untrusted cloud computing service providers steal user’s privacy data,this paper uses the homogeneous linear difference equations with constant coeffcients as a tool,applies secret sharing technology in cloud computing,and proposes a novel(m+1,t+1) threshold secret sharing scheme.This scheme manages the decryption key of the user privacy data,and distributes a special secret share to user and a common secret share to each computing service provider by homogeneous linear difference equations with constant coeffcients.Cloud computing service providers cannot recover the user’s privacy data without the user’s involvement.Analysis reslut shows that the scheme resolves the problem that untrusted cloud computing service providers steal user’s privacy data,and reduces the cost of memory overhead by optimizing secret share.
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Computer Engineering. 2017, 43(1): 13-19.In order to improve the computing and storage capacity of mobile cloud data storage remote server,this paper proposes an improved mobile cloud data storage algorithm.Firstly,it constructs resampling expected propagation time calculation model by considering node failure probability with the voting data distribution and voting data processing framework,and establishes the dynamic voting network integrating energy efficiency and fault tolerance.It uses the probability distribution estimation method to optimize the storage routes of dynamic network model.At the same time,it uses Gibbs sampling to solve the problems of high-dimensional coupling and unsupervised training of sample data and non supervision training.Experimental results show that compared with the greedy algorithm,random placement algorithm and Estimation of Distribution Algorithms(EDAs),the proposed algorithm has high energy efficiency and storage reliability.
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Computer Engineering. 2017, 43(1): 20-26,31.
Complex Event Processing(CEP) is an effective approach for real-time event stream monitoring,processing,analyzing and mining.Core concepts and basic elements of CEP are introduced.Major areas that utilizing CEP technology are reviewed,such as Internet of Things(IoT),cloud computing,grid computing,Business Process Management(BPM) and computation finance.Based on these applications,cloud based distributed parallel CEP technologies are introduced.By analyzing the requirements of future stream processing systems,it is concluded that such cloud based CEP technology is an important direction for the development of future CEP systems.Potential new areas that require such cloud based CEP system for complex stream event processing are explored,such as power system intelligent control,instrument control and intelligent measurement.Guidance can be provided for the utilization of the CEP technology for now and future.
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Computer Engineering. 2017, 43(1): 27-31.The Data Transfer Time(DTT) is one of the dominating factors of task completion time in the data-intensive architecture of datacenter.A reasonable Virtual Machine(VM) placement method can effectively resolve the above problem.A good optimal VM placement result can obtain short DTT in the data-intensive datacenter and get the optimal task completion time in the datacenter.Aiming at this characteristic,this paper presents an optimized VM placement model so as to minimize the DTT.From the view of model analysis,the proposed model is a NP-complete problem.A corresponding proof is given in this paper.Simultaneously,a heuristic algorithm is given to solve the proposed model.Experimental results show that the proposed method can reasonably optimize VM placement and effectively decrease DTT in the data-intensive datacenter.
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Computer Engineering. 2017, 43(1): 32-36,42.
For the secure issues of outsourced data in cloud storage,a new method of data integrity verification is proposed,which can support secure deduplication and public verification.The method combines the advantages of Proofs of Ownership(POW) and Proofs of Retrievability(POR),and achieves client-side secure deduplication and data integrity verification simultaneously,in which data block,random sampling and dynamic coefficient are used.By introducing bilinear pairings and erasure codes,users can infinitely verify whether the data is intact in cloud storage.If the data is damaged,users can repair it with erasure codes.To achieve privacy preserving,the technology of random masking is introduced,which can hide the information of users’ data effectively.Analysis results show that the proposed method not only can assure the security and integrity of data stored in cloud storage,but also can efficiently reduce the computing cost and communication cost.
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Computer Engineering. 2017, 43(1): 37-42.Storm is an open source distributed real-time computation system.It takes round-robin scheduling algorithm to achieve task distribution balancing,but the Storm default scheduling algorithm disregards inter-node network communication overhead,which may cause the problem of high processing latency and low throughput.To solve these problems,the concept of Storm topology hot-edge is proposed.The proposed algorithm can reduce the number of tuple which is transmitted through network by scheduling the hot-edge connected source exeactor and target executor to the same cluster node,which in turn promotes calculation performance of Storm cluster.Experimental results show that the proposed scheduling algorithm can reduce the Storm processing latency and cluster inter-node traffic,and improve system throughput,which is conducive to cluster load balancing.
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Computer Engineering. 2017, 43(1): 43-49.When the grid point method is used in the remote sensing satellite covering method over the ground,if the object region to be analyzed is very large and the requirement for precision is very high,the space complexity and time complexity will be increased and calculation efficiency will be reduced.To solve these problems,based on geometric topology,this paper proposes a new remote sensing satellite covering method over ground.It considers the track of satellite transit at a time and the object analysis region as geometric figure.It uses intersection operations of spatial geometric relationships to calculate the coverage area of the track of satellite transit and object region for each transit coverage area,and reuses each transit coverage area by using union set operations to calculate the total coverage area.Finally,it analyzes other coverage features.The advantage of this method is only using the operation between graph edge and point sets in the process of operation,which greatly reduces the complexity of computation.If the accuracy of calculating the width between two points can be ensured,then the precision of the algorithm will be ensured.Experimental results show that,compared with the remote sensing satellite covering method over ground based on grid,the proposed method reduces the complexity of the algorithm and improves the calculation efficiency by more than six times.
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Computer Engineering. 2017, 43(1): 50-54.In order to reduce the integrity risks and continuity risks in the process of precision vertical guidance of aircraft,and make the Receiver Autonomous Integrity Monitoring(RAIM) algorithm provide the horizontal and vertical integrity for security,this paper proposes a Multiple Hypothesis Separation Solution(MHSS)-based RAIM algorithm to solve Vertical Protection Level(VPL).The algorithm is based on the premise that the integrity and continuity of the Global NAvigation Satellite System(GNSS) can be met,and the optimal Vertical Protection Level(VPL) is obtained by optimizing the allocation of the integrity budgets and the continuity risks in each hypothesis failure mode.Simulation results show that the proposed algorithm can provide a more accurate VPL value and increase the availability of the system compared with the traditional slope-based RAIM algorithm.It also has good robustness with the increasing prior probability of satellite failure.
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Computer Engineering. 2017, 43(1): 55-60.For the streaming media system based on the cloud model,more efficient and smooth resource scheduling is strongly required.In the traditional “last-minute migration”,only the load information is used for the migration scheduling.Due to the dynamic fluctuation of the video population,such indirect and single way cannot guarantee effective scheduling.Besides the load information,the video popularity is also used for the migration model,this paper propose a dynamic threshold allocated migration strategy.The allocation thresholds of different videos on each server are obtained on the basis of the new video popularity,and due to the guidance of the allocation threshold distribution,the blindness of request access and session migration can be avoided effectively.Experimental results show that the strategy cannot only effectively improve the request acceptance ratie,but also keep the migration cost low enough.
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Computer Engineering. 2017, 43(1): 61-66,71.Intel,AMD and IBM have their vector extension libraries which accord with their own features.Compared with traditional scalar calculation,the speedup of vectorization technology is higher.Therefore,this paper develops a set of vector math library software for SW26010 processor.Based on the analysis of function commonly used,like series method and iterative algorithm,combined with the trigonometric function,inverse trigonometric function,exponential function and logarithmic function,it researches an efficient vectorization algorithm and carries out realization and optimization.This algorithm supports high precision and high performance calculation,and meets the requirements of floating-point calculation.Test result shows that the precision of the proposed function library satisfies specific application requirements of SW26010.Compared with the Intel VML math library,all functions’ performance improvements are more than 1.1 on average.
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Computer Engineering. 2017, 43(1): 67-71.
Aiming at the real-time requirements and easy upgrode feature for high-speed signal acquisition and processing in Acoustic Doppler Current Profiler(ADCP),a hardware and software co-design method based on Field Programmable Gate Array(FPGA) is proposed.This paper expounds the principle of current profiler and chooses the FPGA as a signal processor.Using Verilog HDL language to describe some modules which are easy to use hardware to implement,such as synchronous data acquisition,filtering and complex correlation calculation.This paper chooses the FPGA’s MicroBlaze soft core as the CPU system,operating process control,determining branch and invoking hardware modules to control echo signal of acquisition,processing and storage.Experimental results show that the real-time feature of FPGA signal processing meets the requirement of the system,and it has high accuracy.
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Computer Engineering. 2017, 43(1): 72-78.As development and production is separate from each other in the manufacturing process of embedded devices,different firmware may contain the same third-party libraries and thus firmware of different devices or different versions of the same device has a large number of the same vulnerabilities already disclosed.Aiming at this problem,this paper presents a firmware vulnerability detection method in embedded devices based on homology analysis to provide reference for firmware vulnerability remediation and reduce unnecessary repetitious analysis.Vulnerability detection is implemented through firmware classification and homology analysis of third-party libraries by binary differential analysis,string constant matching and fuzzy hashing method.Experimental results show that the proposed method can effectively catch buffer overflows and cross-border vulnerabilities in D-Link router firmware as well as remote command injection vulnerabilities in Linksys router firmware.
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Computer Engineering. 2017, 43(1): 79-85.Since the security of standard storage module of traditional vehicle is relatively low,problems like accessing out of bounds or data conflicting may occur while the electronic operating system of vehicles accesses the storage modules.So a storage protection mechanism of operation systems is proposed.The process algebra is used to give the formal verification framework that ensures the storage protection mechanism,and the importance of the AUTOSAR storage protection mechanism from the logical point of view is discussed.A formal model of the mechanism is built using process algebra,and the properties like deadlock freeness,safety and liveness are extracted according to the AUTOSAR specifications.Then the model is implemented using PAT——a modelling and verification tool for process algebra,and the correctness of read-write properties of each storage module is checked.Simulation result shows that compared with conventional car standard,the mechanism conforms with the AUTOSAR OS specification and has higher security.
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Computer Engineering. 2017, 43(1): 86-92.Traditional real-time tasks usually access the shared data using the lock mechanism.This lock synchronization mechanism may cause some phenomena such as deadlock,priority inversion and CPU starvation.It may also cause criticality inversion when used in the mixed-criticality system.So this paper proposes a new synchronization method that combines skip-list and Bloom filter for the mixed-criticality system.The skip-list is used as a shared priority queue and implemented with the lock-free algorithm and the Bloom filter based on the lock mechanism is used for querying if the task is scheduled.Experimental results show that the method has greatly reduced the phenomena of deadlock and priority inversion and increased the multi-core efficiency after the criticality inversed compared with the traditional lock mechanism and ELB-trees.
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Computer Engineering. 2017, 43(1): 93-97.Considering the low CPU speed and the limited storage space of embedded system,after analyzing MapInfo data structure and designing data format,this paper proposes a fast output algorithm of electronic map based on Cohen-Sutherland algorithm.It combines the redundant data filtering and the use of optimization strategy to improve the map display speed.The embedded electronic map code is completed in the VxWorks system by using the proposed algorithm in the program,and the effects show that the program is running smoothly with fast display speed and clear outline,which meets the application requirements of the embedded electronic map for navigation.
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Computer Engineering. 2017, 43(1): 98-104.
Existing service discovery methods only consider atomic service or service composition,which cannot meet the increasing demands of users.Aiming at this problem,this paper proposes a new Web service matching framework based on model transformation.In the process of service discovery,this framework comprehensively considers the execution process information of composite Web services information and Quality of Service(QoS) requirements.It designs a whole Web service composition matching process:it transforms UML model into process model,then transforms process model into process graph and calculates the similarity of two combined Web services.Experimental result shows that the proposed framework can distinguish the different combined Web services and improve the accuracy of service discovery.
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Computer Engineering. 2017, 43(1): 105-108.With the continuous expansion of computer access to the sudden-centralized problems,traditional Least Recency Used(LRU),Least Frequency Used(LFU) and other cache replacement algorithms are difficult to meet the requirements of high hit ratio and low latency.According to the characteristics of the sudden-centralized data access mode,and the access mode influence to the data content popularity trend,this paper designs a new replacement strategy.The replacement strategy uses cache access count,access time,popularity prediction and others cache information to update the priority periodically,which is used to choose the replacement data.Meanwhile,according to the characteristics of the LRU,LFU and LIRS replacement algorithm,this paper compares the new strategy design idea,and the key factors of its replacement priority when the data contents are in different cases.Simulation results on the simulator SimpleScalar shows that the strategies is better than the traditional cache replacement strategy in sudden-centralized access mode.
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Computer Engineering. 2017, 43(1): 109-114,119.Aiming at the problem that existing software implementation schemes of Convolutional Neutral Network(CNN) cannot meet the requirements of computing performance and power consumption,this paper proposes a Field Programmable Gate Array (FPGA)-based accelerator for CNN.The convolution computation unit is paralled accelerated in the coarse-grained paralleled level and the whole process is fully pipelined.This optimization allows 20 multiply-accumulations to finish in a single cycle,which greatly improves calculation efficiency.Experimental results for MNIST handwritten digits character recoghition show that the proposed FPGA-based accelerator can achieve peak performance of 0.676 GMAC/s under 75 MHz,and be 4 times faster than general CPU platform,while the power consumption is only 2.68 percent of it.
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Computer Engineering. 2017, 43(1): 115-119.
Web proxy server cache can reduce network congestion in a certain extent,and it can also reduce server load and user’s access delay.However,the Web proxy cache is just passable in the cache hit rate and byte hit rate,cannot play very well to accelerate network request response effect.Combining supervised learning method,this paper tries to classify the Web log data using Tree Augmented Naive Bayes(TANB) classifier,predicts the Web object,and proposes a new cache strategy with the regularly used Least Recently Used(LRU) algorithm.Experimental results show that TANB classifier is superior to the naive Bayes and BP neural network classifier in the precision and recall index.And compared with LRU algorithm,optimized cache strategy cannot only improve the cache efficiency,but also effectively improve the request hit rate and byte hit rate of Web proxy cache.
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Computer Engineering. 2017, 43(1): 120-125.In large-scale network simulation,there is a huge decrease of its performance because of the large network traffic.In order to solve this problem,a method which reduces network endpoint traffic is proposed.In this method,the computational overhead is reduced by collaborative reduction of dynamic parameters,such as network traffic flows,router queue length,etc.,in the original network simulation scene.The reduced network simulation results are expanded to restore the real results of the original network.Experimental results prove that this method can guarantee the authenticity of transient network traffic simulation,routing queue length and other network behavior parameters and reduce the cost of the simulation.
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Computer Engineering. 2017, 43(1): 126-130.In order to improve the data transmission reliability in Media Access Control(MAC) layer for 802.15.4 network,this paper proposes a Markov chain model of node working process based on unsaturated state,and the derivation calculation is carried out for the steady-state probability of the node status.The two factors affecting the transmission reliability in MAC layer are researched:the failure of node access channel and the limit of maximum retransmission times,and the analytical formula of reliability performance is derived.The influence of the parameters including minBE,NB and λ and two factors on the reliability is analyzed,and the effects of the two kinds of factors on the reliability performance are compared.Experimental results show that compared with the node working model without sleep mechanism,the proposed model can greatly reduce channel conflict,and improve network reliability.
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Computer Engineering. 2017, 43(1): 131-137.Most home networks achieve wireless coverage based on WiFi and ZigBee,but these networks are sometimes unevenly covered due to wireless network devices with different configuration,and too many wireless network devices may lead to high-radiation energy.Aiming at these problems,this paper proposes a cooperative smart home network architecture based on Controller Area Network(CAN) and Bluetooth network,which is divided into backbone network and terminal network,and implements the prototype system.The backbone network is built by CAN,and the terminal network is set up by Bluetooth network.Experimental result shows that the system implemented by the proposed architecture has the advantages of wider coverage,higher communication quality and lower energy radiation,which can effectively support the application requirements of green home network.
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Computer Engineering. 2017, 43(1): 138-143.
The existing methods of constructing Connected Dominating Set (CDS) have some drawbacks,such as redundant steps,much more energy consumption,and not adapting to the changes of dynamic network topology.So this paper proposes an improved algorithm called Energy Efficient Algorithm of Constructing a Connected Dominating Set(EEIA_CDS),which can quickly construct a CDS that is adaptable to the tiny movement of nodes just with a single phase.It simplifies the procedure of construction and reduces the energy consumption.Furthermore,this algorithm takes the additional coverage and remaining energy of sensor nodes into consideration while choosing domination nodes.So it prolongs the survival time of backbone network and avoids energy consumption of frequenting construction backbone network.Simulation result shows that compared with the EEIA_CDS,Flooding algorithms the backbone construction expenditure of the proposed algorithm is reduced by about 31%~46% and the occurrence probability of the BSP is reduced by about 52%~67% while network’s lifetime is increased by 35.5%.
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Computer Engineering. 2017, 43(1): 144-152.In order to improve the delivery hit ratio and reduce network transmission delay and network overhead of data packet in Delay Tolerant Network(DTN),the Topological Graph routing algorithm based on Dynamic Multidimensional Combination(TGDMC)is proposed.Each node dynamically selects nodes that rank in the top s level with the node itself in multiple dimensions to form the relative static local topological graph.As time goes on,the dynamic selection is reflected in the change of the node sets that constitute the local topological graph of each node.According to the continuous meeting between nodes,each node expands its topological graph.Floyd shortest path algorithm is used to obtain the best transfer node set of each node to forward the data packet.Simulation results show that,compared with the Prophet routing algorithm,Bubble Rap routing algorithm and SimBet routing algorithm,the proposed algorithm has a better improvement on average transmission delay,delivery hit ratio and network overhead.
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Computer Engineering. 2017, 43(1): 153-157.The reported Dynamic Shortest Path Tree(DSPT) algorithm can result in frequent update of the Shortest Path Tree(SPT) in dynamic network when the weight of some edges frequently change.And when a router is destroyed or a new router is added into the network,the algorithm is not applicable for constructing the SPT.Aiming at the above problems,an effective maintenance algorithm for SPT is proposed,which can greatly reduce the update of the SPT through dealing with the frequently changed weight of some edges by excluding the unstable edges from the SPT.At the same time,when a router is destroyed or added into the network,the SPT can be effectively maintained in the network through reducing the redundant edge enqueue operation.Experimental results show that compared with efficient dynamic algorithm for computation of SPT,the algorithm’s update time is more efficient.
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Computer Engineering. 2017, 43(1): 158-161,167.
Aiming at poor communication problems of Vehicular Ad Hoc Network(VANET) in the adverse road conditions,this paper proposes a routing optimization algorithm which uses the Global Position System(GPS) positioning system and digital map device to retrieve information such as the speed,movement directions and relative positions among different vehicles.The most theoretically reliable communication path for message transfer is chosen for messaging.When the optimal communication transfer path is hindered by the external terrain environment,the backuq copy fallback mechanism is used to avoid communication obstacle,which can improve communication reliability.Simulation results show that the algorithm,compared with Ad Hoc On-demand Distance Vector Routing(AODV) protocol,has better performance in the success rate of packet delivery,the number of linking disconnection and route discovery frequency,and it can ensure the communication quality of VANET.
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Computer Engineering. 2017, 43(1): 162-167.Decreasing energy consumption of nodes,reducing network latency and improving network throughput are needed to make the entire network continue to work efficiently in Wireless Sensor Network(WSN).Therefore,an Adaptive Back Off Tuning Message Authentication Code (ABOTMAC) algorithm is proposed.Each node uses a fixed transmission attempt rate and tunes its back off window size dynamically based on the current network status,and thus tunes the slot of the successful transmission of a frame length.Simulation results show that compared with Model-based Frame Scheduling(MFS) algorithm and Asymptotically Optimal Back off(AOB) algorithm,the proposed algorithm can reduce network latency and improve throughput of network.
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Computer Engineering. 2017, 43(1): 168-171,177.Aiming at the problem of network handoff in tightly coupled mode under the heterogeneous network,a handoff algorithm combining communication service and motion perception is proposed.According to the mobility of the terminal,this algorithm screens the candidate network set initially,and then tries to find the best network from the candidate network set on the basis of the multi-business features of terminal network for handoff.After the experimental comparison with the handoff algorithm based on the motion perception under different businesses,the results show that the algorithm can avoid unnecessary handoff and reduce the blocking rate of handoff.
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Computer Engineering. 2017, 43(1): 172-177.In Mobile Ad Hoc Network(MANET),aiming at the characteristics that node mobility leads to dynamic network topology changes.So the MANET virus propagation model is proposed with differential equation,and on the equilibrium existence and stability analysis,constructed differential equation system is also conducted.The threshold and demise conditions of the virus transmission are determined,and further effects of node moving speed,communication radius,immunization success rate and immune failure rate on virus transmission in MANET are also studied.Experimental parameters are selected for system simulation,and the results verify the consistency of the experimental simulation and theoretical analysis.
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Computer Engineering. 2017, 43(1): 178-182.The increasing complexity and hard-predictability of network traffic,in addition with diversity by human judgments,make traffic anomaly detection still a difficult problem to solve.By the usage of cloud model theory,as well as analysis and definition for the traffic characteristics,a traffic anomaly detection approach based on cloud theory is proposed,which implements qualitative and quantitative transition.The scale clouds for abnormal situation are generated by existing sample traffic,and then the assessment cloud for anomaly decision is obtained by utilizing the forward cloud algorithm and backward cloud algorithms for the traffic to be measured to reflect the results directly.Simulation results show that the approach is capable of detecting abnormally behaved traffic.
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Computer Engineering. 2017, 43(1): 183-187.To improve the security of server-aided aggregate verification signature,a new security model of server-aided aggregate verification signature against collusion and adaptive chosen message attacks is presented.It analyzes the security of server-aided aggregate verification scheme proposed by Niu et al (Application Research of Computers,2015,No.7),and finds that this scheme cannot resist collusion attack between a server and a signature forger.In view of security shortcomings,an improved scheme is proposed under the new security definition.The proposed scheme is proven to be secure under collusion attack and adaptive chosen message attack.Analysis results show that the new scheme can effectively reduce computational complexity of signature verification algorithm,and it has the fixed length of aggregate signature.
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Computer Engineering. 2017, 43(1): 188-195,200.User password guess research is one of the important parts of password security research.According to the relationship between user’s personal information and user password,analyzes the structural characteristics of the user’s personal information,extends Weir probabilistic context free grammar approach,based on user initials shorthand structure,this paper proposes a probalisitic password attack method.Through training to find the user initials shorthand structure,and introduces it into the user password structure generation algorithm,so as to generate a new more effective password structure,and uses the personal information learnt from the training set to make guess attack as a substitution variable of shorthand structure.User password data set on the Internet is used to design different experimental scenarios.Experimental results show that in the twenty million case of speculation,the guess success rate of the proposed method is far more than John the Ripper wordlist mode,and compared with Weir’s Probabilistic Context-Free Grammar(PCFG) method also has 48.12% increasement.
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Computer Engineering. 2017, 43(1): 196-200.Aiming at wireless communication security problem of Radio Frequency Identification(RFID) the based on Elliptic Curve Cryptography(ECC) algorithm,this paper proposes a RFID mutual authentication protocol.It describes in detail the process of the new protocol and gives the safety analysis,the proposed protocol not only provides two-way authentication RFID reader and tag system,and meets the protecting against replay attacks,eavesdropping attacks,middle attacks and other security requirements.The security new protocol is proved by BAN logic.Security analysis result shows that the security of ECC is based on the difficulty of Elliptic Curve Discrete Logarithm Problem (ECDLP),comparing with other asymmetric cryptography,ECC has stronger security,shorter key length,smaller storage capacity and it has high communication efficiency.
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Computer Engineering. 2017, 43(1): 201-206.Incremental attribute reduction algorithm is one of the important research contents in the area of dyanmic data mining.To reduce the storage space of binary discernibility matrix,and by combining the advantages of the binary discernibility matrix that it facilitates the calculation and is visual,this paper proposes a method to compress binary matrix.It simplifies the binary discernibility matrix storage space from |C|+1 column to three columns.Through dynamically updating the binary discernibility matrix to incrementally get core.According to the core,the paper proposes an incremental attribute reduction algorithm based on binary discernibility matrix.Example calculation and experimental simulation prove the effectiveness of the algorithm.
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Aggregation Operators of Support-intuitionistic Fuzzy Sets and Their Applications in Decision MakingComputer Engineering. 2017, 43(1): 207-212.The concept of Support-intuitionistic Fuzzy Set(SIFS) is introduced;operational laws and the objective weight for SIFS are defined.Based on the operational laws and the objective weight,the weighted arithmetic average operator and the weighted geometric average operator for SIFS are defined and the proofs of the theorems for them are provided.A method for decision making based on SIFS fuzzy information is constructed,in which the score function and accuracy function for SIFS are defined.In this method,the support degrees of Support-intuitionistic values are used for determining the weights of the target attributes,so that the weights of the attributes become objective values,which increases the objectiveness of the aggregation results.A practical example verifies that this method can be used for the decision making problems under the environment of SIFS fuzzy information.
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Computer Engineering. 2017, 43(1): 213-218.In view of the problem that the distributed database system needs to specify the execution site for transactions in advance,this paper proposes a transaction classification deployment strategy of distributed database by analyzing the distributed database query cost model.The similar transactions which are clustered by hierarchical clustering algorithm are deployed to the same site.Query matrix and similarity matrix are constructed for query transaction in the clustering process.Experimental results show that under the conditions that each slice has the same redundancy,test table data are more than 1 million and the number of concurrent people is 100,the distributed database system based on this strategy has shorter concurrent query time and faster system response rate than centralized database system.
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Computer Engineering. 2017, 43(1): 219-225.In heterogeneous information network,heterogeneous characteristics and complexities of the nodes and links increase the difficulty of link prediction.Aiming at this problem,this paper proposes a link prediction method by using synthetic topology characteristics.For different meta-paths,it uses the topology characteristics of heterogeneous and homogeneous information network to obtain heterogeneous and homogeneous data.It uses Logistic Regression(LR) model as a link prediction model,and integrates topology characteristics to further improve the prediction accuracy.Experimental results in real heterogeneous movielens film data sets show that the proposed method can improve the link prediction performance of actor cooperation relationship in heterogeneous information network.
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Computer Engineering. 2017, 43(1): 226-230.Features are usually considered as independent of each other in traditional pattern recognition methods.The neglect of the correlation among multimodal features is part of the reason for recognition error.Aiming at integrating multimodal features,this paper presents a hypergraph framework.Under hypergraph model,this paper defines a new measure called shared entropy to capture the multivariate correlation among the multimodal features.Each feature is abstracted as a vertex,and if the value of shared entropy reaches the threshold,a hyperedge can be built.Then,the hypergraph is clustered into a set of partitions using the modularity instead of cut-edges to measure the community degree of sub-hypergraphs.Finally,combining the weak classifiers learned from each partition,a multiclass Boosting method is used to form the last strong classifier.Experimental results show that this method can improve the recognition accuracy effectively compared with the current popular methods such as linear Support Vector Machine(SVM) and Multiple Kernel Learning(MKL).
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Computer Engineering. 2017, 43(1): 231-236.In order to solve problems of the Restricted Boltzmann Machine(RBM) encountered in functional Magnetic Resonance Imaging(fMRI) brain functional connectivity detection,including excessive number of voxels and difficult to choose model parameters,this paper proposes a RBM method,which combines Principal Component Analysis(PCA) with Bootstrap interval estimation.It is introduced to select a part of voxels from fMRI data,so as to reduce the number of voxels,taking the time courses of remained voxels as sample and training RBM with improved learning algorithm.According to the weight parameters of the model,the spatial maps of the brain functional networks are constructed.Experimental results show that,in brain functional connectivity detection of single subject,the analysis results of RBM method in spatial domain and time domain are significantly better than sparse approximation joint restricted Boltzmann machine method.The spatial domain ROC curve of the RBM method and Infomax ICA are very close,but the temporal time course of the former is more relevant to the BLOCK of experimental stimulation.Experimental results show that the RBM method can effectively reduce the number of the voxels in sample and complexity of the model parameters,thereby improves the performance of RBM in fMRI data analysis.
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Computer Engineering. 2017, 43(1): 237-240,246.This paper presents an improved algorithm about Support Vector Machine(SVM) and a pattern recognition algorithm based on distance to solve the problem of the use prediction of equipment.It finds the optimal hyperplane of SVM using the training data,and uses a characteristic set of test data as classification criteria to predict the classification results.The combination of the classification results and the probability is used as the input of pattern recognition algorithms,and the output is a pattern.Experimental results show that,compared with traditional algorithms,the accuracy of pattern recognition algorithm using improved SVM classification as input is better than traditional ones,it can be widely used in pattern recognition algorithms with binary input.
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Computer Engineering. 2017, 43(1): 241-246.Advanced Persistent Threat(APT) whose main goal is to steal information becomes a dangerous attack in recent years,which can bring high risk and persistent attack to the mobile devices.The detection features of mobile terminal intrusion detection are not readily available,so the accuracy of detection model is not high enough and there is the over-fitting problem,which lead to poor detection effect.For these problems,this paper proposes an optimized detection model using static detection technology to extract terminal devices’ static features which helps optimize the sensitivity of the model to the malicious application.It uses sliding window iterative algorithm to extract the delaying attack feature so as to optimize the model’s detection capability of delaying attack and uses Boost technology to fuse the classification algorithms including the decision tree,logistic regression and Bayesian classifier.Experimental results show that the model can increase the detection accuracy of APT effectively and avoid over-fitting problem.
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Computer Engineering. 2017, 43(1): 247-252,258.Aiming at the problem that traditional tag-based recommendation algorithm only considering the user’s rating information leads to the low accuracy of recommendation,this paper puts forward an improved collaborative filtering recommendation algorithm.It builds the Latent Dirichlet Allocation(LDA) model for user-tag matrixes and resource-tag matrixes and explores the latent semantic topics in the recommendation system.The probability of users choosing resources from the semantic level is computed.Then the probability is combined with resource similarity calculated through collaborative filtering algorithm to predict user preference values to realize personalized recommendation.Experimental results on the Movielens dataset show that the proposed algorithm can eliminate the semantic ambiguities such as synonyms and polysemes,and improve the accuracy of recommendation,compared with the traditional tag-based recommendation algorithm.
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Computer Engineering. 2017, 43(1): 253-258.Target label confusion and loss are usually caused by occlusion and detection missing in multiple object tracking process,which leads to failing tracking.Aiming at this problem,an improved tracking method based on Gaussian Mixture Probability Hypothesis Density(GM-PHD) filter is proposed.The binary image mapping and testing sets are got by Background Subtraction Detection(BSD),and the object appearance is detected by detector based on the appearance.The two testing sets got by background subtraction and appearance detector are fused.The improved GM-PHD filter is used to keep the object tracking trajectory so as to deal with some uncertainty in object tracking.Experimental results show that the tracking precision of the proposed method is superior to that of GM-PHD method,color appearance method and SMC-PHD method.
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Computer Engineering. 2017, 43(1): 259-267.
Most traditional object detection approaches extract features manually,which can hardly detect specific objects in complex High Resolution Remote Sensing Imagery(HRRSI).For solving the object detection in HRRSI,a Multi-Structure Convolutional Neural Network(MSCNN) model is constructed to learn object features automatically.Four CNNs with different network structures are designed to extract features from low-level,mid-level to high-level with respect to various scales by considering the size and as well as the number of convolution filter in the convolution layers and the number of layer.Then,the outputs of the four CNNs are concentrated and put into a BP network for training a classifier.This paper uses the sliding-window method to search the object.Experimental result on airplane detection in HRRSI shows that MSCNN has obvious advantages than single-structure CNN.It not only reduces the false alarm rate by 3%,but also improves the recall rate by 6%.Experimental result on oil tank detection further shows that MSCNN can be used in the detection of the other objects in remote sensing imageies.
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Computer Engineering. 2017, 43(1): 268-273.In order to improve the pedestrian target matching accuracy under multi-camera horizons,this paper presents a globally optimal matching model based on unsupervised significant learning and local feature matching.It associates object matching between different horizons.Direct matching of each pair of camera is enslaved to the supervision of their indirect matching,and some errors in direct matching are corrected.The image frame is divided into a number of local blocks after brightness compensation,and significant score of image block is obtained through the unsupervised significant learning.Combined with the similarity scores of target image block feature matching,the similarity score between two objects is calculated by using bi-directional similarity calculation,and regarded as the input of the model.Experiment is based on two standard databases:WARD and Shinpuhkan2014,and the result shows that the proposed model can improve the object matching accuracy under multi-camera surveillance network.
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Computer Engineering. 2017, 43(1): 274-279,286.Existing descriptors are generally associated with principal direction.When the images are transformed,deviation usually occurs in the principal direction of the descriptors,which leads to unsatisfactory image matching results.In order to solve this problem,a binary descriptor construction method based on Local Binary Pattern(LBP) with equidistant rings is proposed.The sampling model of Equidistant Ring Local Binary Pattern(ErLBP) and matching strategy of grouping are introduced into descriptor constructing and matching,so that the descriptor is rotation-invariant.In this way,the principal direction problem is solved and the speed of descriptor matching is improved.Experimental results show that this method is more accurate and speedy compared with other state-of-the-art binary descriptors,such as BRIEF,BRISK.
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Computer Engineering. 2017, 43(1): 280-286.To solve the problem of parameter selection in the algorithm of texture image segmentation based on Gabor filter,a texture image segmentation algorithm is proposed in this paper,which predicts the number of texture types and the parameters of Gabor filter bank.Firstly,the image is divided into regional blocks.Then,the number of texture types is predicted by the texture feature vector of regional blocks,and the parameters of Gabor filter bank are predicted by the characteristics of various texture features.Finally,texture features of the original image is extracted by using the predicted filter bank,and the image is clustered and segmented based on the predicted number of texture types.Experimental results show that the proposed algorithm can process the segmentation in the texture image with higher precision and faster speed,and is less affected by the number of texture types.
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Computer Engineering. 2017, 43(1): 287-291.This paper proves that the enumeration counting recursion formula of max-heap is appliable to binomial tree heap(binomial tree that obeys the heap property) based on intensive study of the property of binomial heap.The enumeration number of binomial tree heap calculated from the enumeration counting recursion formula of binomial tree heap can make up an enumeration series.Then,the enumeration series is expressed as a generating function which is simplified into a power series based on adding,differentiating,integrating,and other operation of the generating function,thus,simplifying the enumeration counting recursion formula of binomial tree heap thoroughly and obtaining the enumeration counting formula of binomial tree heap.According to this result,the enumeration number of binomial tree heap can be calculated directly.Experiment proves that the direct calculation method has a higher calculation efficiency than the recursive method.
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Computer Engineering. 2017, 43(1): 292-296.Focusing on the problem of the unclear data distribution in the Brain-Computer Interface(BCI),a novel approach based on Adaptive Neighborhood Similarity(ANS) is proposed for the Movement Related Potential(MRP).Using the pattern similarity,it searches the optimal direction which maximizes the ratio of the expectation distance between the between-class and the within-class.The similar probabilities are calculated directly with the samples’ distances in the mapped space,avoiding the inapplicability caused by using traditional distances measurement in high dimensional space directly.In the application of two datasets,one generated randomly and another from BCI competition,the classification accuracy of ANS is slightly better than the comparison algorithms of Linear Discriminative Analysis(LDA) and Discriminative Spatial Pattern(DSP).The results evaluate the effectiveness of ANS algorithm.
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Computer Engineering. 2017, 43(1): 297-302.Traditional intelligent engineering machinery uses monocular or binocular recognition for environmental target recognition,which is inefficient and has low recognition rate and poor adaptation to the environment.A target recognition method based on point cloud clustering feature histogram is proposed in order to improve the ability of environmental target recognition for the excavator.After processing the raw point cloud data by filtering algorithm,the data is split into several single clusters using clustering algorithm.Point cloud characteristics histogram of be recognited cluster is built.In the model library,k neighbor is got by using neighbor search algorithm,and the final recognition result is got according to matching degree.The experimental results show that the method works with strong robustness for target recognition of intelligent excavator.It can identify multiple targets in complex conditions and has high recognition rate.
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Computer Engineering. 2017, 43(1): 303-308,315.The existing Spatial Localization Quantization Point(SLQP) algorithm synthesizes virtual sound sources based on all sound tracks,which violates the Vector Based Amplitude Panning(VBAP) basic principle of forming a virtual sound source with three sound tracks.Besides,the sound quality declines for not considering time differences between each track.Aiming at these problems,the paper designs a 3D audio codec framework based on VBAP basic principles with three sound tracks in a group to synthesize virtual sound sources and mixed signals.During decoding,time difference parameter is added and the virtual audio-visual reallocation method based on solution of linear equations is put forward,gaining a reconstructed signal consistent with original sound track in configuration.Experimental result shows that the 3D audio signal generated by this way applies MUSHRA standard to subjective tests,its scores have an average of 12 points higher than existing methods.
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Computer Engineering. 2017, 43(1): 309-315.
Characteristics of human motion are always diverse and complex.The intensity of some actions is quite different at different stages of the movement,but the existing methods don’t take this factor into account when evaluating the similarity of actions,which makes the evaluation results not accurate enough.To address this problem,this paper extracts key frames of four component time series of the most violent joint from reference action sequence by multi-scale Faber-Schauder wavelet interpolation.The four groups of key frames are merged and a threshold is set to exclude the key frames of high similarity.Dynamic Time Warping(DTW) method is used to match the reference action and contrast action to get key frames of the contrast action.The motion similarity score can be calculated by normalizing the average distance between key frames of the two actions.Experimental results show that the proposed method can achieve a better evaluation than other methods and the evaluation result is also better for some similar actions.
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Computer Engineering. 2017, 43(1): 316-321.Previous researches on Hub Arc Location Problem(HALP) mostly adopt hub arcs with fixed discounts which cannot effectively deal with the situation that flows on hub arcs in the hub-and-spoke network have large differences.Therefore,this paper proposes a Hub Arc Location Problem with Unfixed Discounts(HALPUD) based on improved assumptions amd uses a piece-wise linear function to simulate the unfixed discounts.It establishes a mathematical model of the HALPUD,discusses the optimal solution features,and designes an algorithm based on Lagrangian relaxation.Experiments on the standard Civil Aeronautics Board(CAB) datasets show that,for different scale of the problem and different piece-wise linear functions,the Lagrangian relaxation algorithm can always get results quickly.The algorithm has good solution efficiency and quality.
2025
Volume 51 No 6
Volume 51 No 6
(Started in 1975, Monthly)
Superintended by:
China Electronics Technology Group Corporation
Sponsored by：
East-China Institute of Computer Technology
Shanghai Computer Society
Edited & Published by：
Editorial Office of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428
Superintended by:
China Electronics Technology Group Corporation
Sponsored by：
East-China Institute of Computer Technology
Shanghai Computer Society
Edited & Published by：
Editorial Office of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428