05 April 2012, Volume 38 Issue 7
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Computer Engineering. 2012, 38(7): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2012.07.001A method of Event Graph(EG) based Parallel Discrete Event Simulation(PDES) is presented in this paper, because developing Logical Process(LP) based PDES in existing PDES programming environments is a difficult and time-consuming process. This method adopts Model Driven Architecture(MDA), and the system implementation can automatically generate from EG model via transformation mechanism. It shifts the focus of PDES development from writing code to building models, and facilitates the developing efforts for PDES applications. Experimental results show that EG models can successfully execute in parallel simulator, and this method can effectively improve the PDES modeling activities.
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Computer Engineering. 2012, 38(7): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2012.07.002Taking the QoS of failure detection into consideration, a Framework of Disaster-Tolerance Oriented Adaptive Failure Detection (DTO-FDF) is presented, which adopts hierarchical modularity design and constructs the DTO-FDF and algorithm from the system view and data circulation sequence. DTO-FDF mainly includes three modules, monitoring module, processing module, responding module. By monitoring and gathering the data of node, according to evaluation index and configuration policy, combining with the designed failure detection algorithm, the system judges the machine is alive or not. Based on the result of decision, the system makes the take-over response and the system migration. The framework makes some benefic work for the study of failure detection module of universality and independence.
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Computer Engineering. 2012, 38(7): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2012.07.003Aiming at the problem of high lose packet rate in Vehicular Ad Hoc Network(VANET) in which vehicle nodes move at high speed, this paper proposes an improved algorithm based on greedy routing algorithm, which is combined with Link Duration(LD) and data sending delay. Based on relative velocity between neighbor node and current node, next hop node is selected, whoes LD is longer than sending delay. Simulation results show that the rate of transmission error is decreased by the improved algorithm.]
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Computer Engineering. 2012, 38(7): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2012.07.004This paper proposes a map complexity measuring method for hierarchical pathfinding algorithm. Aiming at maps with different size, it defines a relative Hamming distance to measure the complexity of maps by computing the ratio of the actual complexity and the maximum complexity of a map, and map region variance is introduced to compute complexity of maps with different obstacle distributions. Experimental results show that the method can reflect the complexity of maps with different sizes and different obstacle distributions better, and it has a strong correlation to the efficiency of HPA* algorithm.
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Computer Engineering. 2012, 38(7): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2012.07.005According to the bit excited in the layers with different characteristics of the vibration signal, the delay information of the bit into an another stratum can not be extracted accurately by real Short Time Fourier Transform(STFT) and wavelet transform in the case of low SNR. This paper puts forward a complex Morlet wavelet transform analysis. The message of the amplitude and the phase has a good sensitivity to the mutation, so the mutation position can be extracted and then the time when the drilling bit is into different stratum is determined in real time. Experimental result prove that complex Morlet wavelet transform can accurately characterize the time-frequency information and the delay time information. Compared with the STFT and the real wavelet transform, complex Morlet wavelet transform has a better time localization and noise suppression capabilities.
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Computer Engineering. 2012, 38(7): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2012.07.006The traditional serial development mode restricts vehicle information system development progress. To solve this problem, this paper presents a simulation of the vehicle equipment and operating system, real-time access to device communication curriculum vitae, to achieve the parallel development of vehicle information system. Though real-time access to running information of the vehicle equipment, and monitoring the operation of vehicle equipment, the system can effectively reduce the development of the error rate. Simulation results show that the system can effectively achieve the vehicle information system of parallel development and test.
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Computer Engineering. 2012, 38(7): 19-21,24. https://doi.org/10.3969/j.issn.1000-3428.2012.07.007Aiming at the problems of the falling decoded video quality of Scalable Video Coding(SVC) under the error prone transmission network, this paper proposes the real-time feedback-based fault tolerant strategies suitable for low bit rate transmission. The strategies make full use of the inter-layer prediction of spatial layers and enhance feedback-based conventional intra Macro Block(MB) update and Reference Picture Selection(RPS) fault tolerant techniques. The strategies are tested by using SVC common test conditions, and results show that the strategy average Y-PSNR of decoded pictures is higher in rate control, and it is suitable to low bit rate transmission enviroment.
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Computer Engineering. 2012, 38(7): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2012.07.008Receive Antenna Selection(RAS) in broadband Multiple Input Multiple Output(MIMO) system is studied in this paper. Based on the mathematical model for cyclic prefix assisted broadband MIMO system, a suboptimal antenna selection criterion with the goal of maximizing the capacity is designed by exploiting the correlation between neighboring subcarriers. Then the RAS algorithm combining with convex optimization method is analyzed and improved. Simulation results show that suboptimal criterion has almost the same performance as optimal criterion, and the improved RAS algorithm can effectively enhance system performance with small increase of computation amount.
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Computer Engineering. 2012, 38(7): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2012.07.009The performance of verification in remote attestation is discussed. Existing methods do not take query frequency of application software integrity metrics into consideration. So the query path length of every application software integrity metrics is equal. It directly makes the average query path length of application software integrity metrics become so long. A mechanism presented builds a Huffman tree according to application software integrity metrics probability distribution of inquires, which makes a node inquired frequently get a shorter query path. Results show the average query path gets shorter. And the efficiency of the verification is improved highly.
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Computer Engineering. 2012, 38(7): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2012.07.010In order to solve the problem that users have little trust in Cloud Service Provider(CSP), this paper proposes a trust model based on Service Level Agreement(SLA) and user ratings. It determines the service quality by analyzing the SLA supplied by the cloud service provider, observes their fulfillment of SLA through user ratings, and combines the two aspects to calculate the trust degree of the service. Analysis results show that users can accurately find a trustworthy CSP by this model.
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Computer Engineering. 2012, 38(7): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2012.07.011To reduce the frequent subgraph canonical detection time complexity, this paper discusses the relevant properties of the canonical adjacency matrix. In order to reduce the generation of redundant candidate subgraphs, it proposes the theorem to reduce redundancy candidate subgraph generation, and proves its correctness. Based on this, it proposes a frequent subgraph mining algorithms called FSM_CAM. Experimental results show that FSM_CAM algorithm’s efficiency is greatly improved compared with existing frequent subgraph mining algorithms FsubGraphM.
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Computer Engineering. 2012, 38(7): 34-36,39. https://doi.org/10.3969/j.issn.1000-3428.2012.07.012In order to improve the efficiency of the fault injection automation test for high-performance fault tolerant computer. This paper designs a fault injection test automation platform based on the open source automated testing tool Software Testing Automation Framework(STAF). This paper discusses the distributed operation environment and the platform software architecture, and describes the flow diagram of the algorithm. Experimental result shows that the platform can improve the reusability of the test tasks and reduce the testing time.
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Computer Engineering. 2012, 38(7): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2012.07.013In order to better meet user’s personalized demand and support the context-aware service, this paper proposes an Event-based Context-aware Framework(EBCF). This framework consists of sensor layer, event bus and application service layer. EBCF adopts triggered mechanism based on event to get context information and communicate with users. Besides, rule-based filtering mechanism is discussed to screen invalid event. Application results show that the framework can reduce the burden and improve the aware efficiency of system.
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Computer Engineering. 2012, 38(7): 40-41,45. https://doi.org/10.3969/j.issn.1000-3428.2012.07.014This paper improves the Discrete Particle Swarm Optimization(DPSO), presents a pairwise covering combinatorial test data generation algorithm. A particle represents a test set, fitness function is evaluated by the number of combination pair, and the position of the particle is produced by stochastic algorithm, which is randomly generated by the frequency of discrete values of all factors in test set. Example analysis shows that the algorithm has nothing to do with the initial value and can generate the most effective test data with fast convergence.
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Computer Engineering. 2012, 38(7): 42-45. https://doi.org/10.3969/j.issn.1000-3428.2012.07.015To solve the problem of trust evaluation mechanism for information recommending in networks, this paper proposes an information formalized recommendation method based on trust evaluation. A formalized model of information recommendation is proposed. Trust evaluation method, which is composed by node confidence and node trustable relationship, is presented according to nodes’ different roles of information source, information recommender or information receiver. The recommendation path trust can be calculated through above trust computation. Based on trust evaluation, information recommending algorithm is proposed. Experimental results show the validity of the method.
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Computer Engineering. 2012, 38(7): 46-48. https://doi.org/10.3969/j.issn.1000-3428.2012.07.016This paper analyzes and improves the generational garbage collection algorithm, proposes an optimization algorithm for Garbage Collection(GC) based on embedded Java Virtual Machine(JVM). It adopts dynamical generational approach, and divides the old generational recycle task into smaller segments. In this way, it can make full use of the heap and shorten the pause time which is caused by whole heap recycle. Experimental results show that the algorithm can shorten the average system pause time and bring high recycle efficiency.
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Computer Engineering. 2012, 38(7): 49-52,56. https://doi.org/10.3969/j.issn.1000-3428.2012.07.017This paper presents a moving objects snapshot K Nearest Neighbor(KNN) query algorithm based on range query, named SKNN. It estimates the subspace containing the result set and uses the subspace as range to efficiently compute the KNN Points of Interest(POIs) from the query points to reduce I/O cost. It introduces cache to shorten the average response time of query. Experimental results show that after introducing cache, SKNN has better performance while scaling to a very large number of moving objects.
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Computer Engineering. 2012, 38(7): 53-56. https://doi.org/10.3969/j.issn.1000-3428.2012.07.018In order to generate near-minimum test case sets in the pairwise test process, this paper proposes a pairwise test case generation algorithm based on contribution. It creates a set of ordered pair to satisfy a given combinatorial coverage criteria, based on which an initial test sets is generated, and reduces the number of test sets. Experimental results show that the algorithm is effective and has the characteristics of fewer test cases.
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Computer Engineering. 2012, 38(7): 57-59,69. https://doi.org/10.3969/j.issn.1000-3428.2012.07.019Aiming at the problem of semantic boundary determination difficulty in semantic query expansion, this paper proposes a method of query expansion based on ontology and local context analysis. It filters the candidate expansion concepts according to the local context on the basis of acquiring candidate expansion concept based on ontology expansion, improves the filter function and filters expansion words twice. Experimental results indicate that the query performance of the method is improved greatly compared with the ontology based query expansion method.
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Computer Engineering. 2012, 38(7): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2012.07.020The traditional Web services framework does not support Quality of Service(QoS)-based queries, and can not meet the performance requirements of service users. Based on ontology, this paper establishes the QoS ontology, proposes a two-stage service matching algorithm that based on function and QoS, and an algorithm of QoS-feedback which integrally computes the release and feedback QoS of the service. Experimental results show that the new approach can enhance the precision rate, and improve the performance of service discovery.
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Computer Engineering. 2012, 38(7): 63-65. https://doi.org/10.3969/j.issn.1000-3428.2012.07.021In a Rayleigh fading environment, an Optimal Power Allocation(OPA) scheme is proposed for the linear multi-hop network based on physical-layer network coding. Under the system outage probability constraint, the OPA scheme is realized by minimizing the total power consumption and using convex optimization theory. Numerical result shows that the OPA scheme can get the optimal transmission of each node power, and it reduces the total transmit power, especially when the node number or the path loss factor is large.
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Computer Engineering. 2012, 38(7): 66-69. https://doi.org/10.3969/j.issn.1000-3428.2012.07.022This paper proposes an improved Distance Vector-Hop(DV-Hop) localization algorithm, because of a big jump from the error of using the DV-Hop algorithm to compute the distance from unknown node to beacon node and computing the jump distance of neighbor node in the Wireless Sensor Network(WSN). In the path from unknown nodes to anchor nodes, it considers the influence of three adjacent nodes angle to the distance, and computes the angle through the adjacent nodes overlap. It introduces average connectivity degree compute hop distance to more accurately calculate the distance. Simulation result proves that the improved algorithm can increase location precision and coverage rate.
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Computer Engineering. 2012, 38(7): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2012.07.023This paper presents a robustness aware routing algorithm in error-prone Wireless Sensor Network(WSN). Considering factors of link error rate and collision record which affect the network robustness, it realizes routing decisions through calculating a minimum delay cost function. In routing selection stage, it uses a method of avoiding potential interference and collision to reduce delay caused by retransmission and backoff. Experimental results show the algorithm can reduce the transmission delay, improve network lifetime and transmission reliability.
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Computer Engineering. 2012, 38(7): 73-76. https://doi.org/10.3969/j.issn.1000-3428.2012.07.024This paper proposes a multi-sink optimal routing algorithm for Wireless Sensor Network(WSN) based on fuzzy comprehensive evaluation. The algorithm considers factors contain the least residual energy in path, the least average link quality in path and hop counts from sensor to sink. It involves routing discovery, data transmission and routing update to obtain distributed routing. OMNeT++ simulation result shows that this algorithm can prolong the network lifetime enormously, enhance the packet delivery ratio greatly, and reduce the number of control messages largely in process of routing establishment.
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Computer Engineering. 2012, 38(7): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2012.07.025Aiming at node energy consumption problem in Directed Diffusion(DD) routing protocol, this paper proposes an improved DD routing protocol. It is used for dispersed optimizing flooding diffusion of the detecting packet. The improved DD protocol limits the source node and each forwarding node diffusion breadth by defining the gradient threshold, and controls diffusion depth by using the set of path delay parameter. Simulation results show that the improved DD protocol can reduce the data packet amount, and improve the utilization rate of network energy.
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Computer Engineering. 2012, 38(7): 80-82,86. https://doi.org/10.3969/j.issn.1000-3428.2012.07.026A jitter buffering control algorithm based on Auto Regression(AR) model is proposed according to the changing regularity of network flux. A network business flux prediction model with burstiness and self-similarity is built by an improved RMD arithmetic. It sets buffer area size based on the prediction value of network flux, and improves the buffer setting precision. Result of assessment to Quality of Service(QoS) of Voice over Internet Protocol(VoIP) and simulation of jitter buffering control algorithm by using Matlab software shows that the MOS value outscores secondary level, and the mean value reaches a better level, the QoS of VoIP is improved.
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Computer Engineering. 2012, 38(7): 83-86. https://doi.org/10.3969/j.issn.1000-3428.2012.07.027In order to improve the cooperative spectrum sensing efficiency and reduce feedback overhead of the system, this paper proposes an optimal cooperative spectrum detection method with dynamic threshold adjustment. Based on the minimum detection error probability of a single sensing node, the expression between the threshold and the Signal Noise Ratio(SNR) is derived under the energy detection, and dynamic threshold under different channel environments is obtained by using dichotomy method. The number of optimal sensing nodes is obtained according to the constant detection rate and constant false alarm rate, and the system detection error probability is obtained by combining the optimal number of sensing nodes with the adaptive threshold. Simulation result shows that the proposed method can improve the detection probability and reduce the detection error probability.
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Computer Engineering. 2012, 38(7): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2012.07.028The network redirection model is proposed and cross-domain migration of Virtual Machine(VM) is achieved Local Area Network (LAN) or in Wide Area Network(WAN). With Address Resolution Protocol(ARP) synchronization, the unidirectional IP tunnel is quickly established between the source node and the migrated VM. The data is redirected to the VM. With dual IP stacks, all new requests are responded by the new IP and old sessions are maintained. Experimental results show that the model can effectively reduce the deployment time, optimize forwarding path, lower latency, achieve transparent cross-domain migration.
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Computer Engineering. 2012, 38(7): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2012.07.029The error performance of Additive White Gaussian Noise(AWGN) channel and Rayleigh fading channel is analyzed. Then the relation between diversity gain and communicating reliability over Rayleigh fading channel is studied. A formula of code error probability upper bound is derived for wireless communication system in which linear block code is applied. It shows the relation between diversity gain of linear block code through Rayleigh channel and its minimum hamming distance. Based on Monte Carlo method, the simulation is carried on this problem. A comparative analysis is made on the experimental and theoretical result, and results show that the diversity gain of linear block code under relay fading channel is equivalent to its minimum hamming distance.
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Computer Engineering. 2012, 38(7): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2012.07.030Current propagation models of mobile phone Bluetooth virus do not consider the space characteristic and random moving characteristic of the mobile nodes. This paper introduces three parameters including the infection rate of nodes, the immune rate of nodes, the distribution density of nodes to propose a propagation model of mobile phone Bluetooth virus based on mean-filed theory, and analyzes the effect of the parameters to the spread of the virus through simulation. Experimental results show that the model is closer to the real environment of mobile phone Bluetooth virus spread rule, and it can simulate the spread process of the virus accurately.
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Computer Engineering. 2012, 38(7): 96-98. https://doi.org/10.3969/j.issn.1000-3428.2012.07.031In accordance with the pseudorandom properties of pseudorandom sequences, this paper investigates the cross-correlation functions between Welch-Gong(WG) sequences and Hyperoval sequences(decimated Hyperoval sequences with one particular exponent) for odd n by using the Walsh spectrum representations of trace functions from to . In the correspondence, it shows that the calculation of the cross-correlation functions between WG sequences and Hyperoval sequences(Glynn Ⅱ of Hyperoval sequences under an -decimation) are all related to the cross-correlation functions between m-sequences and their decimations.
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Computer Engineering. 2012, 38(7): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2012.07.032The paper proposes an Adaptive Model Generation(AMG) model based on Hybrid Genetic Algorithm(HGA) and data mining. An improved clustering algorithm is used to divide the normal/abnormal behavior library that is from network and system behavior records. HGA is used to dig out the invasion rules, the rules are put into the rule base, and detection is realized by hybrid detection module. Experimental results show that the AMG model can detect unknown intrusion with higher detection rate and lower false detection rate.
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Computer Engineering. 2012, 38(7): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2012.07.033This paper proposes an intrusion detection algorithm based on sparse representation. The sparsity constraints are imposed to over-complete dictionary learning and sparse coding so that the sparse coefficients have better reconstruction and discrimination. The discriminative K-SVD algorithm is exploited to optimize the dictionary and the linear discriminative function, and then extracted features are fed into a linear classifier to implement the intrusion detection. Experimental results show that the algorithm achieves lower false alarm rate and higher detection rate, and it has a good performance in intrusion detection. ?
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Computer Engineering. 2012, 38(7): 105-106,109. https://doi.org/10.3969/j.issn.1000-3428.2012.07.034Designated verifier signature scheme can protect signer’s personal sensitive information not be revealed. Taking advantages of the scheme and based on random oracle model of the difficulty assumptions, this paper proposes an efficient proxy signature scheme with designated verifier. Theoretical analysis shows that the scheme can meet the verifiability, strong unforgeability, strong undesirability, and designated verification, meanwhile, and it can resist replay attack.
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Computer Engineering. 2012, 38(7): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2012.07.035A 5-round meet-in-the-middle distinguisher is constructed by exploiting the properties of Rijndael-256 cipher. It shows that, if only the first byte is variable in the input data state, then each byte differential value of the output of fifth round Rijndael-256 encryption is completely determined by the first byte value in the input data state and 25 constant bytes with a probability of 2-96. Based on the distinguisher, a meet-in-the-middle attack on 9-round Rijndael-256 is proposed. Analysis reslut shows that the attack requires data complexity of about 2128 chosen plaintexts and time complexity of about 2211.6 9-round Rijndael-256 encryptions.
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Computer Engineering. 2012, 38(7): 110-112,115. https://doi.org/10.3969/j.issn.1000-3428.2012.07.036Most Intrusion Detection System(IDS) are weak in real-time response attacker’s action, so it can not predict attacker’s action well. Aiming at the problem, this paper puts forward an attack prediction model between attacker and IDS based on repeated game. It establishes the stage game model with the two players and gives the Nash equilibrium, gets the unique sub-game perfect Nash equilibrium when the game plays infinity times and chalks up the probability of every strategy of two players in stage 1~ stage t according to the Quantal Response Equilibrium(QRE) model with the Gambit simulation. The model is simulated in Ad Hoc network by using the GloMoSim, whose results show that compared with Nash equilibrium model, QRE equilibrium model gains better prediction effect.
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Computer Engineering. 2012, 38(7): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2012.07.037The traditional two-dimensional Logistic mapping which generates uniform pseudo random number is not high. This paper proposes a research on improved pseudo random number algorithm. It uses the iterative optimization techniques, based on the analysis of the one-dimensional Logistic mapping and two-dimensional Logistic mapping, and through the introduction of the modular operation to solve the sequence of super-sector issues. Experimental result shows that the uniformity of pseudo random periodic and security of the improved algorithm produces is better.
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Computer Engineering. 2012, 38(7): 116-118,121. https://doi.org/10.3969/j.issn.1000-3428.2012.07.038In secure multiparty computation, fairness is an important property, which guarantees all parties receive their outputs. However, it is impossible to achieve complete fairness without an honest majority. To overcome this impossibility, in malicious model, a fair and secure multiparty computation protocol for general functionality is proposed based on garbled circuits and by using commitment and cut and choose technology. Analysis results indicate the agreement guarantees security and fairness when honest party is t≥4.
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Computer Engineering. 2012, 38(7): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2012.07.039This paper presents a (t, n) threshold proxy (c, m) threshold signature scheme. It finds that either the original scheme or two improved schemes are vulnerable to collusion attack and public-key substitute attack. By including the identities of the actual signers in the proxy signature generation phase, it proposes a new threshold proxy threshold signature scheme with the property that the actual signers from the proxy group are identified and traceable. Analysis results show that the scheme can resist the mentioned attacks efficiently.
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Computer Engineering. 2012, 38(7): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2012.07.040In Zhao’s network coding signature verification scheme, the adversary can forge the new message by using legitimate messages, which can be verified in verification process, so that pollution attack is successfully conducted. Aiming at the shortcoming in signature and verification process, by adding a computing element in the verification formula, the scheme can prevent attacker forging messages to resist pollution attack and enhance the security of the scheme.
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Computer Engineering. 2012, 38(7): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2012.07.041In order to overcome the drawback that a low generalization performance is reached since the bone samples are emphasized too much in hard margin algorithms, this paper presents a new weights adjusting algorithm of soft margin weak classifiers for AdaBoost. Based on adjusting the combination coefficients of weak classifiers, a soft margin is defined by adding a slack item to the hard margin, and a new soft margin AdaBoost-QP algorithm is proposed to optimize the margin distribution of the samples to adjust the weights of weak classifiers by a Quadratic Programming(QP). Experimental results show that the new algorithm can decrease generalization error, and improve the performance of AdaBoost.
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Computer Engineering. 2012, 38(7): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2012.07.042Aiming at the Weapon Target Assignment(WTA) problem in the formation air defense, a method that the WTA problem is modeled as a Distributed Constraint Optimization Problem(DCOP) is proposed, and this paper introduces two typical algorithms Asynchronous Distributed Optimization(ADOPT) and Dynamic Programming Optimization Protocol(DPOP) to solve DCOP. Based on Frodo software platform, it simulates the process of the warship against anti-ship missile. By comparing the two algorithms on the simulation time, amount of information sent and other aspects of performance, this method is proved to solve the WTA problem feasibility.
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Computer Engineering. 2012, 38(7): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2012.07.043This paper provides a method of the automatic annotation by means of the synthetic use of the grammatical information to realize the judgment and automatic annotation of the semantic relationship of textual coherence. The distribution rules of the parts of speech are used to eliminate the non-conjunctions, and the potential conjunctions are tagged. The pattern of the textual coherence is obtained by the synthetic use of the collocation distance, collocation strength and syntactic position after matching the pattern in the corpus of conjunctions. Based on the above data, the semantic relationship is tagged. Experiment shows that the method is effective.
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Computer Engineering. 2012, 38(7): 134-135,138. https://doi.org/10.3969/j.issn.1000-3428.2012.07.044In order to solve the problem that the traditional features such as Mel Frequency Cepstral Coefficients(MFCC) can not reflect the difference between instruments accurately and intuitively. Musical instrument classification based on atomic parameters with Matching Pursuit(MP) sparse decomposition is proposed. In the simulation experiments, the atomic parameters are extracted with MP method from the instrument signals as the features to be classified using Support Vector Machine(SVM). Simulation results show that the musical instrument classification based on sparse decomposition atomic parameters with MP is effective and the recognition rate reaches 89.17%, 17.37% higher than MFCC.
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Computer Engineering. 2012, 38(7): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2012.07.045For the problem of the traditional variational method to solve difficultly, the approximate solution of a variational optimization problem is proposed. Combining the simplicity of least squares approximate solution with the parameters less of the particle swarm optimization algorithm, it introduces the particle swarm optimization algorithm in the process of solving the least squares approximate solution, and gives the solution process. The numerical simulation results show that the algorithm is a simple calculation, and its optimization effect is better.
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Computer Engineering. 2012, 38(7): 139-141,144. https://doi.org/10.3969/j.issn.1000-3428.2012.07.046In the process of multi-attributes automated negotiation based on multi-Agent, because the negotiation Agents pursue their respective interest, the negotiation is sometimes at a stand. This paper proposes a multi-attributes negotiation model based on artificial immune algorithm for solving above question. The model uses the artificial immune algorithm and considers the negotiation goal as antigen and considers the candidate proposal as antibody. By the immune process of antigen and antibody, the model enables the Agents to achieve a win-win trading program. Simulation experiment proves the validity and usefulness of this model. This paper provides a new approach for finding the optimal negotiation solution. It solves the impasse during the process of negotiation and improves the efficiency and adaptability of negotiation.
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Computer Engineering. 2012, 38(7): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2012.07.047This paper proposes a method of speech emotion recognition based on fusion of sample entropy and Mel-frequency Cepstral Coefficients(MFCC). Sample entropy statistic and MFCC are modeled with Support Vector Machine(SVM) respectively to obtain the probabilities of happy, angry, bored and afraid. The sum and product rules are used to fuse the probabilities to gain the final decision. Simulation results demonstrate that the recognition rate obtained with the proposed method is high.
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Computer Engineering. 2012, 38(7): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2012.07.048Accurate localization of acoustic sources in high noise and reverberation environment is a problem for traditional source localization algorithm. This paper proposes a novel acoustic source localization algorithm for microphone array——Minimum Entropy-stochastic Region Contraction(ME-SRC). The algorithm shows that acoustic source with Laplace distribution can be developed to estimate time delays between microphones on a basis of ME and SRC is used to localize the acoustic source in search space. Results show that the proposed ME-SRC algorithm is much more robust than GCC-PHAT in noise and reverberation environment.
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Computer Engineering. 2012, 38(7): 148-151,154. https://doi.org/10.3969/j.issn.1000-3428.2012.07.049In order to obtain more accurate salient object from an image in the absence of priori knowledge, this paper proposes a visual saliency detection algorithm based on Log-Gabor filter and hypercomplex Fourier transform. It uses Log-Gabor filter to process input image and obtain color and texture feature, constructs a hypercomplex image using feature images, and calculates its Fourier transform phase spectral. It calculates visual saliency map by normalization. Experimental results show that the proposed method outperforms state-of-the-art methods remarkably in visual saliency and has better detection results in traffic sign detection.
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Computer Engineering. 2012, 38(7): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2012.07.050￢RDF introduces the classical negation of answer set programming into RDF, which improves the capacities of the expression and reasoning of semantic Web. However, due to the introduce of classical negation, sometimes there is inconsistence when reasoning ￢RDF with answer set programming, which causes the program to no solution. This paper learns from the ideas of weighted answer sets, and forms Weighted ￢RDF(￢WRDF). It discovers implicit facts through weighted answer sets. Example proves that the reasoning method provides the best solution to the users’ needs when the program is inconsistent.
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Computer Engineering. 2012, 38(7): 155-157,160. https://doi.org/10.3969/j.issn.1000-3428.2012.07.051If the sample sets are very little, the accuracy of classification will be influenced. A classification algorithm based on Cellular Automata(CA) on small sample sets is presented to improve the classification accuracy by evolution of the cellular space, which uses the conversion rules of cellular automata and the rules of the classification. This algorithm has the characteristics of extending to high dimensional space and parallel computing, it can also classify data in the case of a small samples and uneven distribution of the data. Experimental results show that the algorithm can enhance the accuracy of classification.
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Computer Engineering. 2012, 38(7): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2012.07.052The traditional constant modulus blind equalization algorithm has some disadvantages such as slow convergence speed, large mean square error, and easily falling into local minimum points. Aiming at these shortcomings, wavelet blind equalization algorithm based on artificial immune system is presented. In the presented algorithm, the equalizer coefficient vector is regarded as antibodies and the optimal solutions can be obtained by replication, mutation and suppression. It can make weight vector escape from local minima and approach the global minima. Its convergence speed can be improved via using orthogonal wavelet transform and its mean-square error can be reduced by artificial immune algorithm. Simulation results show that this presented algorithm has rapid convergence speed, small mean square error and can obtain global optimum solution.
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Computer Engineering. 2012, 38(7): 161-163,167. https://doi.org/10.3969/j.issn.1000-3428.2012.07.053On the basis of the Locality Discriminative Canonical Correlation Analysis(LDCCA), this paper proposes a new supervised learning algorithm called Generalized Locality Discriminative Canonical Correlation Analysis(GLDCCA) algorithm, which can utilize much effectively the class information of samples in the covariance matrix. Meanwhile , Kernel Principal Component Analysis(KPCA) is used to solve the small sample problem and avoid the linear constraint which PCA is subjected to. Experimental results on artificial data sets, facial database including ORL and Yale show that the proposed GLDCCA algorithm is superior to CCA, LDCCA in recognition performance.
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Computer Engineering. 2012, 38(7): 164-167. https://doi.org/10.3969/j.issn.1000-3428.2012.07.054In order to overcome the shortcomings of a poor ability of local search of Differential Evolutional(DE) for solving Knapsack Problem(KP), Lamarckian-Baldwin hybrid DE algorithm is proposed. The algorithm with two populations are based on the original DE, and the local search operator based on Lamarckian evolution and Baldwin effect are adapted to enhance the individual’s ability of local search, which guides the orientation of evolution. Simulation results of the improved DE algorithm show the algorithm has the advantage of rapid converging and high precision and it is effective in solving KP.
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Computer Engineering. 2012, 38(7): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2012.07.055Capacitated Arc Routing Problem with Refill Points and Multiple Loads(CARP-RP-ML), stems from road network maintenance, is the CARP with refill vehicles which can refill several times because of multiple loads. A heuristic and genetic algorithm is proposed to solve CARP-RP-ML. The Heuristic Algorithm(HA) adapts a split algorithm, designed based on two types of vehicle, on each random permutated individual to construct the feasible solution of the problem. The Genetic Algorithm(GA) uses the split algorithm described in heuristic algorithm to calculate the fitness of individuals and to determine feasible vehicle routes and replenishment locations, and adopts local search as the mutation to expand search space. Experimental results show that GA outperforms HA, which demonstrates that GA can more efficiently solve CARP-RP-ML.
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Computer Engineering. 2012, 38(7): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2012.07.056This paper researches the effect of five senses’ local features in face recognition, according to the effect of five senses, these features are quantized. The value quantized is called effect weight. Five senses are located and divided into five regions, each region uses Principal Component Analysis(PCA) to selecting features. The improved genetic algorithm is used to get the number of each region’s features while maximizing the recognition rate. Experimental results show the proportion of each region is the effect weight in this situation when Support Vector Machines(SVM) is used to recognition.
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Computer Engineering. 2012, 38(7): 174-176. https://doi.org/10.3969/j.issn.1000-3428.2012.07.057For the integration of multiple classifiers, each base classifier performance is different, if the weights are the same for each classifier, it is bound to affect the classification of base classifier. This paper proposes a weighting method Binary Crossover Particle Swarm Optimization (BCPSO), in which each individual sub-classifier uses random subspace method to generate and output the final classification by the combination of rule by weighted voting. Experimental results show that the method is feasible and effective, it has high classification accuracy.
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Computer Engineering. 2012, 38(7): 177-178,181. https://doi.org/10.3969/j.issn.1000-3428.2012.07.058Fractional differential operator can enhance the high frequency signals of the image, while retaining the low frequency profile information, so it has a strong detail enhancement capability. But the best order of fractional differential needs to be specified by the researchers, affecting the actual application of the fractional differential. This paper analyzes the disadvantage of the algorithm and proposes the improved method. It chooses the fractal dimension, which can express the complexity of the detail of the texture, as a parameter adaptive to determine the order of differential. Experimental results show that the improved algorithm has better result in the edge extraction of the image.
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Computer Engineering. 2012, 38(7): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2012.07.059This paper improves the traditional Mixture of Dirichlet Process(MDP) nonparametric algorithm . The Markov Random Field(MRF) as spacial neighborhood is involved, and a new nonparametric image segmentation algorithm is constructed in this paper. Combined with MRF special neighborhood prior, the image segmentation results are smoothed and the cost of time is reduced. Comparative experiments in noisy natural images and magnetic resonance images show that the accuracy of improved algorithm is higher.
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Computer Engineering. 2012, 38(7): 182-184,187. https://doi.org/10.3969/j.issn.1000-3428.2012.07.060To improve quality of medical image and give help to clinical diagnosis, an adaptive Non-local Means(NLM) denoising algorithm based on gradient information is proposed. The improved algorithm employies the gradient direction information to adaptively rotate the local similarity window so that more matching pixels are found. Based on least square idea, relationship model between the optimum parameter for the gradient amplitude threshold and the noise standard variance is established. Therefore, the adaptive selection of filtering parameter is realized. Experimental results show that the algorithm attains superior denoising effect and is appropriate for post-processing of medical image.
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Computer Engineering. 2012, 38(7): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2012.07.061To solve the intensity inhomogeneity in the segmentation of Magnetic Resonance Imaging(MRI), this paper presents a new multiphase level set model for brain image segmentation. The proposed model uses local image intensities and thresholding method for initialization to segment White Matter(WM), Gray Matter(GM) and Cerebrospinal Fluid(CSF). Experimental results show that the proposed method can effectively segment multiphase brain image and provide a smooth contou, and it does not need reinitialization.
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Computer Engineering. 2012, 38(7): 188-189,192. https://doi.org/10.3969/j.issn.1000-3428.2012.07.062Aiming at the limitations of the un-convex of energy functional in the active contour model, which makes the segmentation result sensitive to noise and the location of initial contours, a new model is proposed to make it be convex by the way of an un-constrained, and provides the fast algorithm based on the TV-norm. Experimental results on synthetic and medical images show that the proposed model can converges to a global minimum, accurately and fast segment the object, and is robust to image noise.
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Computer Engineering. 2012, 38(7): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2012.07.063Searching tracking particles in complex fluid field always involves great difficulties due to its poor following performance. In order to solve the problem, this paper proposes a novel virtual particle image tracking method and applies it in the fluid field analysis. By selecting predetermined image blocks as virtual tracking particles, the movement of fluid can be vividly illustrated by tracking the movement of these virtual particles with image cross-correlation algorithm. Experimental results show that the tracking error in two successive images can be as low as 10-2 pixel, and the method has the merits of high accuracy and flexibility.
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Computer Engineering. 2012, 38(7): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2012.07.064There exits the structure discontinuous phenomenon when the strong structure texture image is inpainted by exemplar-based image inpainting algorithm. In view of this problem, this paper presents an improved algorithm for exemplar-based image inpainting. It introduces structure tensor in computing data term, and realizes anisotropic linear structure to determine the inpainting order of the target patch. The priority is the sum of confidence term and data term. Experimental results show the improved algorithm is effective in inpainting structured texture images.
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Computer Engineering. 2012, 38(7): 196-197,200. https://doi.org/10.3969/j.issn.1000-3428.2012.07.065In order to find the image containing the corrosion from lots of X-ray image, a new method of model recognition is offered in this paper. It constructes the Gray Level-gradient Co-occurrence Matrix(GLCM) for each X-ray image and the eigenvector by 5 characters of the matrix according to the feeling of the people to the corrosion. It transforms the eigenvector to the Vague sets and recognizes the corrosion by calculating the similarity between the character Vague sets and the target Vague sets. Experimental result shows that this algorithm has higher identification accuracy than BP neural network and single Bayes classifier.
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Computer Engineering. 2012, 38(7): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2012.07.066This paper proposes an optimization model of Gaussian-SRAD joint model based on adaptive weighting for the problem which has large impact in the gradient of speckle for the normal SRAD model in the ultrasound image speckle processing. It uses minimum number of iterations to reduce the speckle in ultrasound image. After the re-fusion by optimization gaussian pyramid, the proposed model gives the corresponding weight by calculating the similarity between the center point and the remaining point of eight diffusion direction. Experimental results show that the proposed model can inhibit the speckle, accelerate the processing speed and preserve the texture information at the same time.
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Computer Engineering. 2012, 38(7): 201-202. https://doi.org/10.3969/j.issn.1000-3428.2012.07.067Image compression rate is not high at present and global search or genetic algorithm has slow speed to find the optimal fractal image compression coding. The fractals image compression parallel algorithm based on Gene Expression Programming(GEP) is proposed. Binary fractal image compression process of solving Iterated Function System(IFS) is analyzed. The gene and chromosome coding express of fractal image compression, the fitness function and genetic evolution operating of select, mutating, insert string, gene transformation, gene recombination are given. The fractals image compression parallel algorithm based on GEP is structured. Experimental results show that the algorithm has higher compression ratio, and running velocity faster than sequence algorithm on PC cluster, it has a linear speedup ratio.
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Computer Engineering. 2012, 38(7): 203-206. https://doi.org/10.3969/j.issn.1000-3428.2012.07.068Most of the on-board computers can only manage the task and can not complete the complex data operation. Aiming at this problem, this paper implements an onboard data processing platform, the core of which is the Digital Signal Processor(DSP) and Field Programmable Gata Array(FPGA). The DSP controls the whole system and completes some signal processing tasks. FPGA completes most of the signal processing tasks. Test result shows that the unit has a high capability and reliability, and can meet the requirements of space data processing.
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Computer Engineering. 2012, 38(7): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2012.07.069This paper presents a design strategy for system among city vehicles in communication. The system is composed of PowerPC hardware platform and software platform based on embedded Linux operating system. Real-time vehicle location information is obtained by Global Positioning System(GPS) technology. Dedicated Short Range Communication(DSRC) technology is employed to achieve high-speed and two-way interactive communication between city vehicles. ARM9 loaded with embedded Linux operating system plays a role of touch screen display. Test result shows that the system can achieve high-speed, reliable, low-latency communication between vehicles.
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Computer Engineering. 2012, 38(7): 210-212,216. https://doi.org/10.3969/j.issn.1000-3428.2012.07.070This paper studies methods of data replication and integration between heterogeneous databases based on complicated network for a power enterprise’s request on transferring real-time data of their power plants to center database between partitioned networks. It proposes a multi-stage and application-independent scheme for this case. The replication system constructed according to this scheme can save a lot of development costs, and be used in much network environment.
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Computer Engineering. 2012, 38(7): 213-216. https://doi.org/10.3969/j.issn.1000-3428.2012.07.071This paper designs an embedded system with remote and dynamic reconfigurable ability based on reconfiguration technology and Internet Reconfigurable Logic(IRL) method. A software/hardware unified multi-task programming model which greatly reduces the complexity of reconfiguration system is designed to provide unified interface and management for software/hardware task. The remote features increase the ability to upgrade and maintain the system remotely by Internet. Experimental results show the profits of the programming model and the good speedup of the hardware task.
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Computer Engineering. 2012, 38(7): 217-219,223. https://doi.org/10.3969/j.issn.1000-3428.2012.07.072According to the current mine safety and actual needs, this paper introduces a design of mobile Session Initiation Protocol(SIP) communication terminal unit based on embedded Linux. The terminal uses SIP as application-layer protocol which provides the liquidity support for voice continuity during an ongoing session, and designs a flexible and efficient SIP protocol stack which implements in the embedded platform with wireless LAN technology to achieve real-time voice calls under-mine. Experimental results show that the terminal has good calls quality and a broad application and promotion aspects in improving underground communications and other functions.
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Computer Engineering. 2012, 38(7): 220-223. https://doi.org/10.3969/j.issn.1000-3428.2012.07.073Software simulated hardware fault injection can not break through protection of operating system, leaving the fault injection to be limited. This paper presents a hardware fault injection method based on JTAG debugging techniques. By setting break points, setting watch points or sending debugging request to the target system when it is running, the target system can be turned to hardware debugging mode. By shifting bus based scan chain or adding instructions to pipe to change bus data, register data or memory data, fault injection can make effort. Experimental results show that the method can realize fault injection successfully.
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Computer Engineering. 2012, 38(7): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2012.07.074Computing bistatic radar cross section by linear interpolation, the calculation equation of bistatic radar detection range under condition of suppression jamming is presented. If curve gets extreme value, the derivative is zero. The analytical formula of bistatic radar alert region edge is deduced by the principle. Based on the calculation of the edge, the algorithm for the construction of bistatic radar shadow is investigated and the mathematical model of bistatic radar detecting maximum and minimum altitudes at a grid point is put forward. 3D visualization of bistatic radar coverage is implemented with OpenGL. Simulation result shows that the 3D coverage of bistatic detection radar affected suppression jamming is visualized vividly in real time.
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Computer Engineering. 2012, 38(7): 227-229,232. https://doi.org/10.3969/j.issn.1000-3428.2012.07.075In Software Communication Architecture(SCA), Modem Hardware Abstract Layer(MHAL) standard is not adapted to component dynamic deployment on Specialized Hardware Processor(SHP). In order to solve the problem, this paper proposes a SHP component dynamic deployment scheme based on SCA. It introduces the MHAL communication mechanism, and designs hardware assembly descriptor and hardware component descriptor. Based on of all of this, a kind of dynamic deployment solution of SHP component is proposed. Analysis results show that this scheme offers the independence between software and hardware in period of waveform development and deployment, and enhances the compatibility of SCA for SHP.
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Computer Engineering. 2012, 38(7): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2012.07.076Since most algorithms for predistortion are too complex to implement, this paper designs an efficient algorithm of digital predistortion suitable for implementation with two 32×16 Look Up Table(LUT) as the predistortion block, considering the loop delay of the analog/RF circuits and the phase rotation. Coefficients used to predistort input signal are stored in LUT in order to compensate for distortion of Power Amplifiers(PA). With 64-QAM OFDM signal, result shows that this method can improve Adjacent Channel Power Ratio(ACPR).
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Computer Engineering. 2012, 38(7): 233-235,239. https://doi.org/10.3969/j.issn.1000-3428.2012.07.077Aiming at the heating temperature control system of fried tea machine lag to track the set temperature value. In addition, the real-time of automatic adjusting device is poor. In order to solve this problem, a fuzzy self-tuning Proportion Integration Differentiation(PID) parameters controller is designed, which is based on PID control algorithm and fuzzy control algorithm, achieves fuzzy adjusting the PID parameters. The simulation model is created in Simulink of Matlab for analyzing the performance of the algorithm. Result shows that the overshoot, the steady-state error ≈1% and steady-state error es=0 in fuzzy self-tuning PID control system. The method proposed can raise performance of the temperature control system.
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Computer Engineering. 2012, 38(7): 236-239. https://doi.org/10.3969/j.issn.1000-3428.2012.07.078Focusing on pure electric vehicle body control Controller Area Network(CAN) bus system, this paper presents a design of application layer protocol based on CANopen protocol. The structure of the pure electric vehicle body control network and the function of each Electronic Control Unit(ECU) are analyzed. The design of the network management, process data objects and service data objects of each ECU and the define of object dictionary are given. A CANopen network simulation platform of pure electric vehicle body control system is designed by CANoe soft and its components CANoe. CANopen. The real node function is simulated by CAPL program and the control panel is designed by Panel Editor software. Simulation results show that the designed pure electric vehicle body control CANopen network meets well the demands of the car door control system.
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Computer Engineering. 2012, 38(7): 240-242,246. https://doi.org/10.3969/j.issn.1000-3428.2012.07.079In heterogeneous network environments, constructing remote distributed wireless measurement and control system is faced with complex communication problem proposed by online management, data acquisition and coordination control of node devices. Therefore, a framework based on SIP architecture is proposed. By using SIP and its extension, network seamless convergence between Internet and short-range Wireless Sensor Network(WSN) can be achieved. Application result shows that various remote communication and control operations of distributed nodes can be unified and simplified.
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Computer Engineering. 2012, 38(7): 243-246. https://doi.org/10.3969/j.issn.1000-3428.2012.07.080The management of hardware resources and software resources lacks a unified mechanism. To solve this problem, the hardware part of the reconfigurable computing system is discussed, and a hardware task model with unified interface is proposed to allow the operating system a unified management of hardware and software tasks. An efficient hardware task downloader is designed to increase the download speed of hardware tasks. Experimental results show that the proposed hardware design of the task model is completely feasible and efficient, and hardware task downloader can significantly improve the hardware task download speed.
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Computer Engineering. 2012, 38(7): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2012.07.081A novel temperature control method for rice wine fermentation control system is proposed, based on the system consisting of Labview, SIMATIC PLC300 and sensors. In this algorithm, cross-factor Particle Swarm Optimization(PSO) is applied to the BP neural network(MyPSO-BP) Proportion-Integral-Differential(PID) control. The improved particle swarm algorithm initializes the weights and thresholds of neural network, which can be an effective approach to tuning PID parameters on-line, enhancing system stability and robustness and reducing errors. Simulation experiment is performed by Matlab, and simulation result shows that this method compared with the traditional neural network PID controller has a great advantage in temperature control performance.
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Computer Engineering. 2012, 38(7): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2012.07.082Based on wireless network adjacent channel interference, 802.11 DCF model and reasonable interference channel to minimize the wireless card jump times, this paper designs a high efficient and flexible all-channel jammer. This jammer is equipped with two wireless cards. Card “a” monitors network, and card “b” jumps to the proper interference channel and sends radio signals according to the channel number difference from card “a”. Experimental results show that this jammer has the advantages of being flexibility, energy-saving and covering all 13 channels.
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Computer Engineering. 2012, 38(7): 253-256. https://doi.org/10.3969/j.issn.1000-3428.2012.07.083Aiming at instruction Likelihood of Criticality(LoC) of SPEC2000 programs under different clustered superscalar processor architectures, this paper proposes a design of static LoC key predictor. It discusses the instruction LoC, and finds that it has some characteristics, such as architecture-independent and dynamic-invariable. This paper uses this characteristics above to design the predictor. Simulation results show that when 1×8 cluster super-scalar processor uses the design, the program Instruction per Clock(IPC) average increases by 5.3%, and the perfor- mance is better than the dynamic LoC predictors.
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Computer Engineering. 2012, 38(7): 257-259,262. https://doi.org/10.3969/j.issn.1000-3428.2012.07.084In order to improve intra prediction operation speed and reduce the Field Programmable Gate Array(FPGA) hardware resources consumption. An optimized hardware architecture is proposed for an intra prediction of H.264 based on FPGA. The redundancy of prediction values in the same prediction mode and the parallel processing ability are also fully utilized to optimize hardware architecture. The proposed architecture is implemented in Verilog HDL and verifies that it is effective and practical in Altera Cyclone II EP2C20F484C8 FPGA.
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Computer Engineering. 2012, 38(7): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2012.07.085Aimming at the contradiction between fast incremental terrain data scale and graphic hardware processing capacity, this paper proposes a research on realistic rendering technology for large-scale terrain. It is based on the quadtree Level of Detail(LOD) algorithm for large-scale terrain rendering, and gives the storage structure for the terrain quadtree. According to stadia and terrain roughness of double standard to determine the level of detail node. It provides a method which use skirt to mend the cracks cased by different resolution of adjacent node. Experimental results show that the technology can perform reality rendering of the sense and large-scale terrain data management in real time fast.
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Computer Engineering. 2012, 38(7): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2012.07.086In order to defect information accurately from the Pulse Magnetic Flux Leakage(PMFL) signal, a new wavelet threshold denoising method is presented based on Empirical Mode Decomposition(EMD). The Smoothly Clipped Absolute Deviation(SCAD) rule is introduced to optimize the conventional wavelet soft and hard threshold function. The new denoising method is applied to denoise the Pulse Magnetic Flux Leakage(PMFL) signal. Experimental results show that not only the new denoising method can remove the noise in signal, but also the denoising performance for pulse noise is better than conventional wavelet threshold denoising method.
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Computer Engineering. 2012, 38(7): 266-268,272. https://doi.org/10.3969/j.issn.1000-3428.2012.07.087Loop transformations can bring program speedups, but after vectorization, program performance probably cannot benefit as expected. In order to solve the problem which is not done sufficiently by researchers, combining with the features of the targeted architecture, this paper implements a benefit evaluation framework in Open64 based on polyhedral representation. The benefit evaluation model can efficiently analyze cost of various loop transform scheme so that the best vectorization can be chosen as the ultimate vectorization selection. SPEC test set is done including swim and other four programs. Results show that the polyhedral cost model can accurately predict program speedups compared with real time tests and thus avoid blind optimization.
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Computer Engineering. 2012, 38(7): 269-272. https://doi.org/10.3969/j.issn.1000-3428.2012.07.088The emerging approach of tandem mass spectra spectrum library searching in peptide identifications field is introduced. The basic principles of spectrum library building and searching are discussed. The review summarizes populate methods of spectrum library searching from different views, describes its advantages and limitations and provides a primer for researchers with interests in adopting this new approach for data analysis. The future outlook on the evolution and utility of spectrum libraries is also discussed and some optional cut-in points for study are supposed.
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Computer Engineering. 2012, 38(7): 273-275,278. https://doi.org/10.3969/j.issn.1000-3428.2012.07.089The average penalty of Level 1 Instruction Cache(L1 I-Cache) is simply quantified for the next level storage access time, this simple quantitative introduces large errors during analysis of performance bottlenecks. Aiming at the problem, this paper uses interval model to analyze what are the front-end factors that impact on the average penalty, and validate the analytical results through simulation experiments. Result shows that in addition to the next level of cache or main memory access time, fetch bandwidth, the size of the fetch queue, the L1 I-cache miss rate, the branch misprediction rate and the program characteristic can impact on the average of L1 I-Cache miss penalty.
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Computer Engineering. 2012, 38(7): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2012.07.090In order to support the formalization analysis and verification of Web Services-business Process Execution Language(BPEL), a formalization model for Web service compilation——μ-BPEL is designed in this paper. The specific studying process is as follows. The syntax rules and operational semantics of μ-BPEL language are introduced, and establishes the mapping from μ-BPEL to extended timed automata, model checking technology is used to study the service correctness and the test of time-related problems. Research result shows this model can support Web service compilation process effectively, which can better meet the temporal logical properties which sets in the system.
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Computer Engineering. 2012, 38(7): 279-280,283. https://doi.org/10.3969/j.issn.1000-3428.2012.07.091Using 3D geological modeling technology to do geological analysis, this paper proposes a method for TIN-based modeling method. It uses fault as constraint triangular divide method to achieve the Delaunay triangulation of the mass data rapidly, builds the geology model. Stratum and faults as constraint, it is according to the principle of sequence stratigraphy, sequence by grid representation subdivision formation establishing sequence model and structure model based on the weighted distance inverse method for estimation of grid node attribute values to establish geological attribute model.
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Computer Engineering. 2012, 38(7): 281-283. https://doi.org/10.3969/j.issn.1000-3428.2012.07.092For RTL design cannot meet the requirement of the speed of System on Chip(SoC), this paper presents a fast and accurate processor hybrid model based on Electronic System Level(ESL). It uses the proprietary 32 bit embedded microprocessor C*CORE340 based on ESL design methodology. For this target the Instruction Set Simulator(ISS) and Cache adopt the different abstraction layers to construct. Experimental results show that the simulation speeds of hybrid model is a least 10 times faster than that of RTL model, and the less than 10% error rate simulation accuracy is gotten.
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Computer Engineering. 2012, 38(7): 284-286,289. https://doi.org/10.3969/j.issn.1000-3428.2012.07.093This paper mainly discusses the design of automatically making surgical oriented template which is the guide to location, depth and direction of dental implant with the CT image of high precision. With the help of the Visual Studio 2005 platform and support of the VTK, an algorithm based on the technology of fitting curve, image segmentation and 3D reconstruction is proposed. The algorithm realizes 3D reconstruction with the digital data of skull, considering the structure of alveolar bone, the technology of fitting curve is adopt to finish the segmentation to the objective flat region, and helps to effectively and automatically generate the virtual surgical template.
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Computer Engineering. 2012, 38(7): 287-289. https://doi.org/10.3969/j.issn.1000-3428.2012.07.094Aiming at the problem that the Keyword Spotting(KWS) system can not calculate the state likelihood effectively. Based on nearest-neighbor approximation, a new technique named Feature Similarity of Adjacent Frames(FSAF) is proposed. Depending on the high similarity of adjacent frames, it uses some of the maximum mixtures of the previous frame to predict the maximum mixture used by the current frame to calculate the likelihood quickly. Experimental result shows the technique reduces the recognition time by 29.3% over baseline system, but the identification performance is kept, it can be applied to actual projects.
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Computer Engineering. 2012, 38(7): 290-292. https://doi.org/10.3969/j.issn.1000-3428.2012.07.095This paper introduces a forest fire monitoring algorithm based on high-performance cluster computing platform, when the forest fire happens, to get fire information and share different data resources quickly. It introduces the high performance computing platform based on processors, and the parallelization realization of fire identification algorithm based on satellite image, analyzes various factors which affects the operation efficiency. Experimental results show that when chooses the rational number of parallel task, the algorithm can effectively improve the efficiency.
2024
Volume 50 No 3
Volume 50 No 3
(Started in 1975, Monthly)
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board 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
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board 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