20 August 2011, Volume 37 Issue 16
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Computer Engineering. 2011, 37(16): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2011.16.001To solve the conundrum that it is difficult to preserve the color constancy after doing illumination compensation, a novel algorithm based on Low-Pass(LP) filter and Retinex is proposed. In this algorithm, RGB image to be dealt is transformed into HSV space at the very beginning, the H and the S element are kept steady, then by using the LP filter the illumination image V is divided into high frequency and low frequency parts, which are symbolized by VH and VL respectively, in the flowing steps Retinex algorithm is used on the VL image to do illumination compensation, VH and the compensated VL are used to reconstructed V, and the compensated image in HSV space is transformed back to RGB space, where it gets the final image. Through experiment, it is confirmed that the proposed algorithm to do color image’s illumination compensation yields some good results both on illumination compensation and on preserving the color constancy.
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Computer Engineering. 2011, 37(16): 5-7. https://doi.org/10.3969/j.issn.1000-3428.2011.16.002This paper presents a fault diagnosis method using artificial immune model. Using immunological principles, the frame of model is created. The T-module and B-module of the model are designed by simulating functions of T-cells and B-cells. The T-module discriminates anomaly states from the states of the system. The B-module responds the actual states of system and dynamically evolves using clustering principle. The alert information is fed back to the T-module. The interaction of these two modules made the system to achieve on-line detection. This model is successfully applied to rudder fault diagnosis of a certain pilotless. Results confirm the feasibility and effectiveness of this method.
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Computer Engineering. 2011, 37(16): 8-10. https://doi.org/10.3969/j.issn.1000-3428.2011.16.003This paper proposes an Intelligent Repair Evolutionary Algorithm(IREA) based on evolutionary computing. Using Control Flow Graph (CFG) as the individual of the evolution, IREA is directed by the fitness degree of the individual, which is calculated from cardinality of the CFG nodes set constrained by test case and the degree of structure similarity. It converts repair process to evolution process directed by the fitness degree, which intelligentizes the software repair. Experimental results show the feasibility and effectiveness of the proposed algorithm.
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Computer Engineering. 2011, 37(16): 11-13. https://doi.org/10.3969/j.issn.1000-3428.2011.16.004The model of the pose error of Stewart parallel robot is established based on closed-loop vector method. The parallel robot pose error arises from the length error of six drive rods and the hinge error of connection with the upper and lower platform. In this paper, the continuous ant colony algorithm on the basis of mesh strategy for is proposed based on the model of the pose error; the pose error of Stewart parallel robot compensation is obtained by updating the pheromone and guiding the ants search repeatedly and optimizing the error of drive rods. The result of numerical simulation indicates that ant colony algorithm is able to realize the compensation of the pose error of Stewart parallel robot effectively.
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Computer Engineering. 2011, 37(16): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2011.16.005This paper introduces the SC-FDE system random access scheme employing prime number Zadoff-Chu sequence as user signature, and proposes a Zadoff-Chu sequence full frequency-domain detection algorithm based on zeros padding in time-domain. Simulation result shows that the proposed algorithm can reduce the computation complexity by 90% compared to the traditional time-domain detection algorithm while maintaining same detection performance.
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Computer Engineering. 2011, 37(16): 17-20. https://doi.org/10.3969/j.issn.1000-3428.2011.16.006This paper proposes a novel approach for continuous approximate query over trajectory stream based on sliding window. Through local clustering, the sliding window is divide into various sized basic windows and sampling the data elements of a basic window using biased sampling rate, forms trajectory stream synopses. Toward such synopses, it can implement distributed K-Nearest Neighbor(KNN) queries utilizing the plane sweep algorithm of computational geometry. The extensive experiments verify the effectiveness of proposed algorithm and it has better expansibility.
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Computer Engineering. 2011, 37(16): 21-23. https://doi.org/10.3969/j.issn.1000-3428.2011.16.007This paper addresses the problem of carrier frequency recovery in additive noise. Frequency estimation algorithm based on Support Vector Machine(SVM) is derived. The estimator can work efficiently without the need of statistics knowledge of the observations, and the estimation performance is insensitive to the carrier phase; it shows a better performance than traditional Maximum Likelihood(ML) estimation algorithm at low Signal to Noise Ratio(SNR), for SVM-FEA has not the threshold effect.
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Computer Engineering. 2011, 37(16): 24-26. https://doi.org/10.3969/j.issn.1000-3428.2011.16.008Established a trace-file based NetFlow simulation environment to evaluating the applicability of two classes of classic algorithms for finding frequent items in NetFlow. The queries are based on landmark window in experiment. Experimental results indicate that the recall of all algorithms no less than ninety-eight percent, and the correlation between precision and query granularity is weak, but the correlation between precision and amount of items is strong, the correlation between precision and distribution of frequent items is strong. The error of sketch-based algorithm is stable for frequency estimation, and it is better than count-based algorithms. Meanwhile, the performance of count-based algorithms is better than that of sketch-based algorithms.
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Computer Engineering. 2011, 37(16): 27-29. https://doi.org/10.3969/j.issn.1000-3428.2011.16.009In order to fit the requests of Wireless Sensor Network(WSN) nodes with finite resource, a Power Control and Multinode Collaborative (PC&MC) algorithm for target tracking is proposed, which can guarantee the performance of tracking with less complexity. Multinode collaborative working is realized to ensure the precision of mobile target tracking utilizing the design ideal of Rao-Blackwellized technology. The Quasi-Gauss Particle Filter(Q-GPF) based on continuous/discrete mixed model is used to complete target tracking, and power control is used to direct the working of collaborative nodes. The performance of PC&MC algorithm is verified by simulation, the simulating data can prove that PC&MC algorithm suits for WSN nodes, whose resources such as storage and computation are limited, and the precision of target tracking is well improved.
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Computer Engineering. 2011, 37(16): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2011.16.010Reverse Nearest Neighbor(RNN) query between line is put forward. That is finding the line segments that have query line segment as one of their nearest neighbors. According to whether two line segments are intersected, it has two categories: intersected line segment and no intersected. For the former, the reverse nearest neighbor is easy to find. For the latter, by constructing the Voronoi diagram of line segment sets, using the adjacent property and the local property, the line segment RNN query based on Voronoi diagram algorithm is proposed, and the relevant theorem and proof are given. Experimental results demonstrate the proposed algorithms have high query efficiency.
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Computer Engineering. 2011, 37(16): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2011.16.011This paper presents a method based on relationship of requirements, in order to reduce redundant test cases. It begins at corresponding code distribution requirements, defines logic relationship of requirements, based on path coverage of test case set, and proposes a method for public path reduction, and proposes a method for adjusting requirement-test case set. Experimental results show that the method is helpful to reduce the base of further processing and contributes to effective test.
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Computer Engineering. 2011, 37(16): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2011.16.012Aiming at the problem that traditional library function identification technology can not recognize specific library function effectively, this paper proposes a specific library function identification technology based on vague matching. The technique improves the function signature mechanism produced by Fast Library Identification and Recognition Technology(FLIRT), extracts a valid function congregation from the target file and does vague matching using professional library function feature database. Vague matching determines the signature to be loaded, loads the signature and fulfils the accurate matching. Experimental results show that the method does well at specific library function identification.
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Computer Engineering. 2011, 37(16): 39-41. https://doi.org/10.3969/j.issn.1000-3428.2011.16.013The number of File Transfer Protocol(FTP) resources on the China Education and Research Network(CERNET) is quite large. It is difficult to find the resources. Because of this problem, a high-performance FTP search engine is designed based on EdtFTPJ and Lucene. In this engine, Struts1.2 is employed to implement Model View Controller(MVC). Data acquisition module uses finite state machine based on regular expression to grab information. Index module uses inverted index method. Word segmentation algorithm uses maximally match Chinese words segmentation based on dictionary. Query Experimental results indicate that the proposed scheme improves the query efficiency, at the same time to ensure the accuracy of the retrieval results.
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Computer Engineering. 2011, 37(16): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2011.16.014In the traditional association rule mining algorithm, concept hierarchy tree only provides concept hierarchy information of items, and the efficency of searching items is not high in this tree structure. This paper presents an improved multi-level association rule mining algorithm. It adds two fields in its nodes to help to accquire frequent 1-itemsets. It employs an auxiliary storage structure that is based on Hash table, which enhances efficency of searching items. Experimental result shows that mining time of the imrpoved algorithm is reduced by about 10% than before.
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Computer Engineering. 2011, 37(16): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2011.16.015For the problem of strong-association rules mining, a method is proposed which constructs a cell complex on transaction database and uses generalized discrete Morse theory to find the strong-association rule. It gets the definition of generalized discrete Morse theory and strong-association rule by extending the basic discrete Morse theory and association rule, mining the strong-association rule by defining discrete Morse theory on cell complex of transaction database. Example verifies the feasibility and efficiency of the method.
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Computer Engineering. 2011, 37(16): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2011.16.016According to the framework of Interior Point Method(IPM), this paper presents the simpler and simplest correction equation of Quadratic Programming(QP), which has block bordered coefficient and arrow quadratic term matrix. And the arrow structured coefficient matrix of simpler correction equation is formed after rearranging the matrix. A parallel solver for correction equation is proposed by integrating decoupling and the arrow matrix, and the parallel IPM algorithm of QP is presented. Experimental results in the cluster system show that the proposed algorithm is very promising for large structured QP problems due to its excellent speed-up ratio and scalability.
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Computer Engineering. 2011, 37(16): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2011.16.017The method of attribute reduction algorithm based on discernibility matrix needs to compute the discernibility matrix of the decision table. However, computing the discernibility matrix not only spends much time but also needs a large of memory space. In order to get over the defect and use the idea of discernibility matrix methods, this paper presents a new improved attribute reduction algorithm based on the number of all not null objects. At the same time, the definition of the attributes importance is presented and a quickly computed formula is provided. The formula only needs to compute and to compute the attributes importance. Example analysis shows that the time is reduced, and it illustrates the minimum attribute reduction of the new algorithm.
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Computer Engineering. 2011, 37(16): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2011.16.018Ontology as a formalized description of shared conceptual system, can solve the problem of massive knowledge usage in knowledge retrieval. This paper suggests an ontology-based related knowledge visualized retrieval model based on full study of current research. From a practical point of view, the model focuses on the relationship between knowledge sources and user experience of knowledge retrieval, improves traditional ontology construction and maintenance method, and suggests a new knowledge retrieval method. The model can largely improve efficiency and quality of knowledge retrieval by users.
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Computer Engineering. 2011, 37(16): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2011.16.019Aiming at the problem of Fast Fourier Transform(FFT) parallel algorithm on current multi-core architecture not fully use of multi-level caches and thread-level parallelism, by distributing data into multi-level caches and combining computation of subsequence FFT with parallel computing FFT one by one pair, a thread-level parallel and non-recursive FFT algorithm for a N-point, one-dimension, ordered and 2-radix is presented on multi-core computer. Theoretical analysis and experimental results show that the presented algorithm is pragmatic and efficient, and it can obtain very good speed-up ratio and scalability.
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Computer Engineering. 2011, 37(16): 60-61. https://doi.org/10.3969/j.issn.1000-3428.2011.16.020Aiming at problems of solving multiple quadratic equation systems, the redundancy of extending equations by Extended Linearization (XL) algorithm is analyzed. It is proved that there is redundancy in equations extended by XL algorithm. The upper bound, [mn(n+3)?m(m?3)]/2, of the number of linearly independent equations in the new system of equations, which extends from n-variable quadratic equations consisting of m equations, is given. The algorithm is obtained to overcome the redundancy problem and XL algorithm is improved, which effectively reduces the computational complexity of solving multi-variable quadratic equation system.
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Computer Engineering. 2011, 37(16): 62-64. https://doi.org/10.3969/j.issn.1000-3428.2011.16.021How to deal with C pointers is an important and difficult issue in C to Java automatic program transformation System. The existing methods are powerless for ingenious C codes. It is difficult to understand codes generated by some transformation system. These codes are not always correct. This paper presents a set of methods. They implements all the functions of C pointer by Java. This transformation keeps original program structure, and runs as fast as possible. Using it can automatically convert various C pointer applications into correct, clear, changeable and efficient Java code.
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Computer Engineering. 2011, 37(16): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2011.16.022For consistent decision table, the attribute reductions based on relative granularity, relative partition granularity, knowledge quantity and common discernibility degree are equivalent with the algebraic reduction respectively. But they are inconsistent while the decision table is inconsistent. For inconsistent decision table, it is proved that the relationship between new conditional information entropy, knowledge quantity, common discernibility degree and relative granularity is linear. It is followed that the attribute reductions based on relative granularity, relative partition granularity, knowledge quantity and common discernibility degree are just equivalent with the one based on HU’s discernibility matrix. An inconsistent decision table is designed to illustrate the correctness of conclusion.
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Computer Engineering. 2011, 37(16): 68-71. https://doi.org/10.3969/j.issn.1000-3428.2011.16.023In order to deal with the complex direction of the three-dimensional objects, the coordinate mapping model for cardinal direction relations of three-dimensional objects is put forward in this paper, which bases on simple data model and uses projection method and the simplicity of interval operation．On the basis of this model, the basic reasoning operations for cardinal direction relations of three-dimensional objects and the identification of convex relations are discussed. Basing on preceding knowledge, the consistency checking arithmetic for cardinal direction relations of three-dimensional objects and the corresponding correctness proof is given.
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Computer Engineering. 2011, 37(16): 72-74. https://doi.org/10.3969/j.issn.1000-3428.2011.16.024While incorporating constraints in probabilistic XML, it becomes impossible to check the validity of the document against the constraints which involve distributional nodes, for the values of distributional nodes are uncertain. In some scenario, users should return the query answers which meet the constraints and their corresponding confidences. However, the confidences are not exact, for they are conditioned with respect to impossible world space. This paper introduces the concept of probabilistic XML, and gives an effective way to represent possible worlds and constraints in probabilistic XML, presents efficient techniques to solve both conditioning and exacts confidence computation problems. Experimental evaluation shows that the algorithm can work efficiently and the conditioned query answers are more acceptable to users.
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Computer Engineering. 2011, 37(16): 75-76. https://doi.org/10.3969/j.issn.1000-3428.2011.16.025The paper discusses the use of 32 MASM languages in C++ to directly operate to the memory of method, realizes the saving method of super long integral’s garbage arbitrarily, gives the input and output meaning method of super long integral, and the main procedure calculate way frame diagram and procedure flow chart of these methods, analyzes the time complexity and the space complexity needed, for directly in the C++ in adjusted to provide a convenient condition. It makes use of a super long integral operation to replace floating point arithmetic to lay certain foundation.
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Computer Engineering. 2011, 37(16): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2011.16.026Query expansion is an effective way to optimize information retrieval. A method for automatic query expansion based on semantic analysis is proposed. This method uses a co-occurrence model based on mutual information to analyze the retrieved documents, which is a part of the extended source, and uses the results of the analysis to prune the semantic tree generated by the semantic dictionary WordNet to limit the expansion. Extended words selected from both retrieved documents and the semantic dictionary are employed to form a new query set. The new retrieval results are re-ranked to adjust the retrieval precision. Experimental results show this method is feasible.
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Computer Engineering. 2011, 37(16): 80-81. https://doi.org/10.3969/j.issn.1000-3428.2011.16.027Some problems exists in FP-growth algorithm. It must recursively generate huge number of conditional FP-trees that requires huge volume of memory and costs a lot of time. In this paper. It uses matrix technology constrained sub-tree statistic frequent item sets and frequent item sets for data mining. Experimental result shows constraint sub-tree method with matrix technology is an efficient frequent pattern mining algorithm and it has a better time efficiency and space efficiency.
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Computer Engineering. 2011, 37(16): 82-83. https://doi.org/10.3969/j.issn.1000-3428.2011.16.028Adaptive Random Testing(ART) is an enhanced version of Random Testing(RT). There are two factors that restrict the performance of ART, high-dimension data and distance metric. In this paper, an advanced strategy of ART based on test case similarity is presented by analyzing the limitation of ART and enlarging the hypothesis. Experimental result shows that the advanced ART, to some extent, can compensate for the limitations of existing ART and performs better than random test.
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Computer Engineering. 2011, 37(16): 84-85. https://doi.org/10.3969/j.issn.1000-3428.2011.16.029Model driven methods are to solve the low efficiency, poor portability in software development, model transformation is the key technology in development of application tools based on Model Driven Architecture(MDA). This paper introduces the theory about MDA technology, proposes the model transformation method of Platform Specific Model(PIM) to Platform Specific Model(PSM) based on pattern, according the transformation method to establish the transformation rules, it is verified in an instance of MDA application development, this method realizes the transformation from platform independent model to enterprise Java bean model of J2EE in platform specific model.
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Computer Engineering. 2011, 37(16): 86-89. https://doi.org/10.3969/j.issn.1000-3428.2011.16.030Based on the simulation of human movement behavior in real city, this paper quantitatively analyzes six opportunistic network routing algorithms, such as First Contact, Direct Delivery, Epidemic, Spray and Wait, Prophet and MaxProp. In the simulation, different scenarios are set according to node density, node mobility model and the cache size of node. Delivery ratio, delivery delay, network overhead and energy consumption are selected to evaluate the performance of different routing algorithms. Experimental results show node mobility model, the network node density have significant impact on routing algorithms. Different routing algorithms perform better in some special scenarios.
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Computer Engineering. 2011, 37(16): 90-93. https://doi.org/10.3969/j.issn.1000-3428.2011.16.031In this paper, an algorithm is proposed to detect and mitigate congestion, which occurrs in navigating with Wireless Sensor Network (WSN) in emergency. Each node detects the number of users to judge whether congestion is occurred. If congestion occurs, navigate the user to the other path, users can escape from the dangerous area more quickly and safely. Simulation results show this method can control network congestion efficiently, and make the load of roads more balanced.
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Computer Engineering. 2011, 37(16): 94-97. https://doi.org/10.3969/j.issn.1000-3428.2011.16.032This paper refers to several hash algorithms in IP flow detection, and analyzes XOR-SHIFT algorithm using the theory of entropy chiefly. XOR operation is extended to bytes, which can get much more random value from five-tuple because of difference between high byte and low byte of IP address in paceket. As a result, better performance comes into being in hash algorithm, which helps dealing with IP flows conveniently according to flow identifiers.
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Computer Engineering. 2011, 37(16): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2011.16.033Modeling and predicting of network traffic are important for internet management and security prediction. Considering about draggle disposal and bad service quality, different kinds of classic traffic prediction methods are reviewed. Comparison about their suitable data, modeling complexity, prediction precision and suitable scene are presented. Experimental results prove that prediction model should correlate to scene tightly. It need to choose different models according to the traffic characters and prediction target in practices.
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Computer Engineering. 2011, 37(16): 101-103. https://doi.org/10.3969/j.issn.1000-3428.2011.16.034Using the cross-layer technology, this paper presents a real-time transmission algorithm based on clustering in Wireless Sensor Network(WSN). It identifies more than one optimal paths for each cluster head to the base station. It selects an optimal path from the paths with congestion control method. The data will be sent to the sink along this path. Simulation analysis shows that the algorithm provides real-time transmission and conducts congestion control effectively.
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Computer Engineering. 2011, 37(16): 104-107. https://doi.org/10.3969/j.issn.1000-3428.2011.16.035Aiming at the problems that it is difficult to build an optimal multicast tree and its convergence is slowly in layer 2 Ethernet, a new optimal multicast tree construction method is proposed in this paper. This method put IS-IS protocol to compute the shortest path tree for layer 2 Ethernet. By means of the Code-Length-Value(CLV) of expanded link-state bag to improve its notice mechanism, an optimal multicast tree can be easily construct. The optimal multicast tree can be reconstructed fast when network topology changed. Test results show that the method can make the time of multicast tree convergence be reduced from 10 s~20 s to 50 ms and ensure that the tree is an optimal multicast tree.
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Computer Engineering. 2011, 37(16): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2011.16.036The antenna selection algorithm is the exhaustive search method. Its computational complexity grows rapidly as the number of antennas increases. It is quite impractical. Focusing on this problem, a fast antenna selection algorithm based on Sorenson similarity coefficient is proposed. It uses Sorenson similarity coefficient to express the correlation of two vectors, and selects the receive antennas with the largest norm and smallest similarity coefficient by searching the matrix row by row, so the system capacity can be increased most. Simulation results indicate that the capacity of the proposed algorithm is close to that of the optimal exhaustive search algorithm and its computational complexity is low in the case where the number of radio frequency chains is small.
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Computer Engineering. 2011, 37(16): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2011.16.037In Akelarre block cipher algorithm, circle function and cycle shift operation makes the same parity input and output, and exists a form of simple equation between expressly and cipher text, it reduces algorithm security. Aiming at the design weakness, this paper presents an improved parity check attack which can apply to any round of the algorithm to Akelarre by employing the weakness. Result shows that this method can obtain the sub-keys and the corresponding plaintexts when the computing complexity of the improving attack is about 241.
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Computer Engineering. 2011, 37(16): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2011.16.038The virtual Trusted Platform Module(TPM) in Xen platform comes up with a potential risk of Attestation Identity Key(AIK) leakage. This paper addresses this problem by presenting a dual AIK signing mechanism and the corresponding remote integrity attestation protocol. It signs the measurements of platform and virtual machine separately using different AIK. Security analysis shows that the potential risk of AIK leakage can be solved.
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Computer Engineering. 2011, 37(16): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2011.16.039In network intrusion detection, aiming to the problem that high dimensional and large network data results in long training time and low detecting speed of Support Vector Machine(SVM), this paper proposes an approach for SVM intrusion detection based on middle classification hyperplane. Based on clustering normal and attack training samples, by defining approaching degree of boundary surface of every clustering center, quadratic expression of standard SVM is improved; improved SVM is trained with clustering centers to obtain a middle classification hyperplane; then training samples are reduced by defining distance threshold to obtaining Possible Support Vectors(PSV). Experimental results on KDDCUP1999 data-set show that the method is more effective than cluster SVM in reducing training samples and improving the training and detecting speed of SVM .
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Computer Engineering. 2011, 37(16): 120-122. https://doi.org/10.3969/j.issn.1000-3428.2011.16.040This paper proposes a new chaotic block cipher algorithm based on a kind of extended Feistel structure which encrypts 128 bit plaintext to 128 bit cipher text. The S-box in round function is generated by logistic chaotic mapping, and puts 128 bit initial key into cubic map to generate the key of algorithm. Hardware description language of Verilog is used to design and implement the algorithm, and the encryption and decryption process are simulated by Modelsim. Experimental results show that the algorithm has high-sensitive S-box, large key space, and good performance in confusion and diffusion.
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Computer Engineering. 2011, 37(16): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2011.16.041The existing Wireless Transport Layer Security(WTLS) handshake protocol requires to exchange certificates between the client and the server, thus causes considerable communication load. And it allows client to avoid verifying the revocation state of the server certificate, which is a security flaw. In order to solve these problems, this paper proposes an improved WTLS handshake protocol based on Trusted Certificate Verification Proxy(TCVP). It only exchanges certificate identifier between the client and the server, which reduces the message payload. Moreover, TCVP is introduced to verify the online status of server certificate and seals it in a security ticket. By checking the ticket, the client is able to determine if the server certificate is valid without verifying it by itself.
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Computer Engineering. 2011, 37(16): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2011.16.042By analyzing the ID-based signcryption scheme in the random oracle model, it finds that it is not satisfied with unforgeability and public verifiability. This paper proposes a proved certificateless signcryption scheme without bilinear pairing, and it avoids key-escrow in the ID-based encryption system and need not use certification. Analysis result shows that improved scheme is satisfied with unforgeability, verifiability, robustness, non-repudiation, it is adaptable to the wireless network requiring lower bandwidth.
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Computer Engineering. 2011, 37(16): 129-131. https://doi.org/10.3969/j.issn.1000-3428.2011.16.043This paper proposes a signer-traceable ring signcryption scheme. The program achieves anonymous signcryption communication by using ring signatures and attaching some additional information about ring members in ring signatures. If necessary, through the coordination of all nodes, the procedure can track the true identity of the signer. There is no center node in the ring signature, so it is more suitable for mobile Ad Hoc network of controllable anonymous communication. The correctness, pseudonym and security of the new scheme are proved by theory analysis.
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Computer Engineering. 2011, 37(16): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2011.16.044DSR protocol does not consider any safety precautions. On the basis of analyzing the routing protocols DSR and SRP, a high security routing protocol SDSR is proposed. Concrete realization has two aspects: the improved SRP protocol is embedded into the DSR protocol, a routing record compression function is added in the route discovery of DSR protocol. Simulation results indicate that the security of the protocol SDSR is remarkably improved without affecting its basic performance.
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Computer Engineering. 2011, 37(16): 135-137. https://doi.org/10.3969/j.issn.1000-3428.2011.16.045Aiming at the high alarm rate and poor robustness in the existing intrusion detection algorithms, this paper proposes a cooperative intrusion detection algorithm based on sparse representation. The algorithm trains the dictionary for the normal class and attack class, to capture the intrinsic nature of the class characteristics. With the theory of subspace structure, determines the class of test samples according to the error of sparse reconstruction. Experimental results demonstrate that it can guarantee higher detection rate and low false alarm rate, it has good robustness in the imbalanced dataset experiment and has a good degree of differentiation for normal behavior and unusual behavior.
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Computer Engineering. 2011, 37(16): 138-139. https://doi.org/10.3969/j.issn.1000-3428.2011.16.046Most previous verifiable secret sharing schemes with self-selecting sub-key are based on the access structure of threshold. Access structure of threshold assumes that all participants have the same level of power, which is almost impossible in most cases. Based on bilinear pairing, a verifiable general secret sharing scheme with self-selecting sub-key is proposed. The scheme can be applied to general access structure, every participant can share several secrets, and its sub-key can be reused for many times. Analysis result shows that the scheme has validity and security.
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Computer Engineering. 2011, 37(16): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2011.16.047This paper gives a Denial of Service(DoS) attack against the Gossamer protocol, and proposes a novel ultra-lightweight Radio Frequency Identification(RFID) reader-tag mutual authentication protocol. It analyzes the security and efficiency of the protocol, the results show that compared with the SASI protocol and the Gossamer Protocol, the proposed protocol is resistant to the DoS attack and algebra attack, and requires less storage capacity on tags, it is cheaper and securer.
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Computer Engineering. 2011, 37(16): 143-144. https://doi.org/10.3969/j.issn.1000-3428.2011.16.048The digital signatures constructed by bilinear pairings have the advantages of higher security, short key size and high implementation speed This paper presents a new pairing based designated verifier signature scheme and through the theory analysis show that the scheme obtains the advantages of correctness, unforgeability, non-reputiation, non-transferable and signer-ambiguous. It can be applied in bidding and overcome the cheating of the bidding company to obtain the minimum quoting price.
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Computer Engineering. 2011, 37(16): 145-146. https://doi.org/10.3969/j.issn.1000-3428.2011.16.049In this paper, a certificateless proxy blind signature based on bilinear pairings and an efficient proxy blind signature based on discrete logarithm are analyzed on security. There are forgeries in both schemes that any one who has a valid proxy blind signature can forge any message else, and the two schemes do not meet the needs of unlinkability, the proxy signer can link the public signature with the information retained by himself. Wherefore neither of the schemes is secure.
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Computer Engineering. 2011, 37(16): 147-148. https://doi.org/10.3969/j.issn.1000-3428.2011.16.050To solve the computationally intensive problems of large amount of calculation and difficult algorithm realization in the digital watermark scheme based on Singular Value Decomposition(SVD), this paper proposes a blind watermark scheme in Contourlet domain based on Schur factorization. It transforms the cover image by Contourlet transform and obtains block symmetric matrices using matrix splitting method, decomposes the selected symmetric blocks by adopting Schur factorization and qualifies the diagonal elements to complete the watermark embedding, and watermark extraction is the inverse process of watermark embedding. Experimental results show that the scheme has fast speed of embedding and extraction, and it is efficiently invisible and robust.
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Computer Engineering. 2011, 37(16): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2011.16.051To better classify the unlabeled text, this paper presents a text classification approach based on fuzzy relationship. Through defining membership function of test document relationship and test category relationship, the test document and category can be represented as fuzzy sets. Then evaluating the membership degree between test document and each category by computing the correlation coefficient of fuzzy sets, the test document is decided to category using maximum membership principle. Compared with k-NN, experimental result shows that the precision is increased and the classification process is speeded up to a considerable degree.
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Computer Engineering. 2011, 37(16): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2011.16.052Aiming at the problem of finding the maximum module of a polynomial roots. An interval evolution Artificial Fish School Algorithm(AFSA) of finding the largest module of a polynomial roots is proposed. The search interval is mapped to more effective area based on bulletin board information, and its search interval is dynamic and evolved. Furthermore, its convergence is proved. Simulation experimental results show that this algorithm is more efficient and feasible to find the largest module of a polynomial roots, the convergent speed is much faster and the accuracy of result is much higher.
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Computer Engineering. 2011, 37(16): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2011.16.053In order to make full use of the classification information of samples, an Supervised Sparsity Neighborhood Preserving Embedding (SSNPE) algorithm is proposed. It combines the ideas of Sparse representation and NPE, so it can hold the strong discriminating power while preserving the intrinsic geometry relations of the local neighborhoods according to prior class-label information. Nearest neighborhood algorithm is used to construct classifiers, the proposed method is tested and evaluated in the Yale face database and AR face database. Experimental results show that SSNPE has good performance even if pose, illumination, face expression change.
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Computer Engineering. 2011, 37(16): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2011.16.054In Large Vocabulary Continuous Speech Recognition(LVCSR) system, speech decoding parameters——Language Model(LM) weight and insertion cost can greatly affects the recognition performance. But in practice, they are usually hand-tuned through experiment to obtain best recognition performance. This paper proposes the rescoring based method that uses bi-gram LM to optimize the parameters automatically, meanwhile the method of combine line search and Simulated Annealing(SA) search in parameters search space of rescoring, which is globally optimal and is insensitive to initial value of parameter. Experimental results show that the method can dramatically reduce the word error compared with empirical parameter setting method, and gains much faster optimization speed than classical N-best optimization.
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Computer Engineering. 2011, 37(16): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2011.16.055For keeping various of population dynamics in the process of evolution and improving the definition of solution of problems, a fine particle parallel algorithm which called CSGP(Cellular Symbol Genetic Programming) is proposed based on the SGP(Symbol Genetic Programming) algorithm and cellular automaton model. This algorithm has higher success rate and need less computation time. Experiments as symbolic regression and so on are given. The result indicates that the GSCP algorithm has more efficiency and precisely in cost and precision than GEP and SGP.
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Computer Engineering. 2011, 37(16): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2011.16.056Feature extraction method of face image, which boasts simplicity and high recognition rate, is proposed. Partitioning face image by row equally, this method uses mean value of dimensional color space pattern values extracted from each sub-block image in HSV as well as variance, classifying face images with nearest neighbor method in improved Mahalanobis distance method and cross-validated through leave-one-out method. Through test, it turns out that this method can get more than 99.5% identification accuracy in such three common face database as ORL, faces94, faces95.
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Computer Engineering. 2011, 37(16): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2011.16.057In order to fully utilize the advantages of Particle Swarm Optimization(PSO) and Genetic Algorithm(GA) respectively, this paper proposes a new collaborative algorithm based on PSO and GA which is applied to clustering analysis. By constructing two mutual competitive populations, the algorithm produces the optimal individual in a bootstrapping process using relative fitness criteria instead of absolute fitness criteria. Experimental results on real world datasets show that the new algorithm is superior than Genetic Algorithm(GA) based clustering method and basic PSO clustering algorithm since it has higher convergence accuracy.
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Computer Engineering. 2011, 37(16): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2011.16.058Mean Shift based object tracking algorithm may fail while the target is changing in scale or in the interference environment. This paper presents a background filtering for object tracking according to the motion of target. The future displacement and speed of target according to its past moving track are estimated. Based on that, the target liked pixels is removed from the candidate location opposite the moving direction of target. The filter width is determined by the absolute value of target displacement. Experimental result shows the improved approach is robust against the interference background, and reliability of object tracking task is improved.
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Computer Engineering. 2011, 37(16): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2011.16.059This paper proposes a high robustness method of nighttime vehicle location and tracking from the headlight angle of view. By virtual of Kalman filter, a robustness tracking process of each bright spot is realized and vehicle lamps are subtracted exactly according to their motion continuity and shape stability. Pedigree clustering methods based on the temporal and spatial features are brought in to classify the lamps into vehicle lamp groups. The headlight groups selected from the lamp groups are employed in the accurate location and tracking of moving vehicles. The validity and high robustness of this method is proved in the experiment.
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Computer Engineering. 2011, 37(16): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2011.16.060For the clustering of spatial object group constructed based on spatial relationship, this paper presents a clustering algorithm for spatial object group based on information entropy, named ESOGC. ESOGC is different from the other clustering algorithms, and it takes variety data types and the number of objects into full account in spatial object group. Through the change of information entropy within a same region, ants determine whether to pick up or drop the current spatial object group to realize the clustering of spatial object group. Experimental results show it can solve the problems of different data types, attribute value, and number.
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Computer Engineering. 2011, 37(16): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2011.16.061According to the agglutination of Uyghur, a factored-based Uyghur-Chinese translation system is constructed. A confusion network is explored which combines factored-based system, hierarchical phrase-based system Joshua and syntax model in Moses. A new translation method in Uyghur-Chinese translation combining word level and sentence level is proposed. It makes use of MBR to merge sentence level results. Experimental results show that the measure can improve BLUE-SBP by 1.72%.
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Computer Engineering. 2011, 37(16): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2011.16.062Neural signal recorded by the microelectrode array is often the mixture which is composed of action potentials of several neurons near the electrodes and the background noises. Researches on the nervous system information processing mechanism and neural coding and decoding mechanism need know every related neuron’s action potential. Therefore, every neuron’s action potential is essential to be separated from the recorded signal. This paper proposes a method based on Principal Component Analysis(PCA) combined with improved K-means for action potential classification. The action potentials’ features are extracted by PCA, the action potential classification is implemented by the improved K-means algorithm. Experimental results show that the method brings down action potential’s feature dimensions and dependence of the initial classification center for the K-means algorithm, and increases the accuracy and stability of the classification results. Particularly, when processing the low Signal to Noise Ratio(SNR) signals, it can also achieve an expected purpose.
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Computer Engineering. 2011, 37(16): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2011.16.063Based on phase space reconstruction of chaos dynamic system and Volterra series for nonlinear system, Volterra adaptive prediction model for traffic flow is constructed. On the premise that small data set method is used to determine that chaos exists in traffic flow time series, this paper respectively employs average mutual information method and false nearest neighbor technique to choose delay time and embedding dimension so as to perform phase space reconstruction for traffic flow data. Nonlinear prediction model, whose coefficients are real-time updated by LMS adaptive algorithm is constructed by applying Volterra series extensions. It applies this Volterra prediction model to performing simulations for the real measured expressway traffic flow data and chaotic time series generated by Chens and Duffing. Experimental results show that the proposed Volterra adaptive prediction model is capable of effectively predicting traffic flow time sequence and low-dimensional chaotic time sequence.
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Computer Engineering. 2011, 37(16): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2011.16.064The existing Particle Swarm Optimization(PSO) and Genetic Algorithm(GA) can not solve the optimization problems of sampling in large discrete solution space effectively such as endmember extraction in hyperspectral imagery. The theory of PSO is reviewed. Combined with the convex geometry theory, a Particle Swarm Optimization Genetic Algorithm(PSOGA) for endmember extraction in hyperspectral imagery is proposed, which improves GA with the theory of local best structure of PSO algorithm. It carries out the experiments by simulative and real hyperspectral image, and the results between the PSOGA and GA are compared and analyzed. Experimental results prove the convergence rate of PSOGA is much faster than GA’s.
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Computer Engineering. 2011, 37(16): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2011.16.065Aiming at the problem of multiple model estimation in nonlinear system, the Quadrature Kalman Filtering(QKF) is employed to the process of the Interacting Multiple Model(IMM) algorithm and an interacting multiple model algorithm based on QKF is proposed. The Jacobian matrix of nonlinear equations is unnecessary and a little better error performance can be obtained than that of the interacting multiple model algorithm based on unscented Kalman filtering. Simulation results show the effectiveness of the new algorithm.
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Computer Engineering. 2011, 37(16): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2011.16.066An optimization mathematical model of Timetabling Problem(TP) is established. The framework structure to solve TP is founded. According to characteristics of TP, Genetic Algorithm(GA) is introduced, a variety of improved schemes are designed, which include new binary code scheme, initial population design scheme, fitness function design scheme, niche strategy, adaptive crossover probability and adaptive mutation probability design scheme. Simulation results show that the proposed GA can satisfy multiple constraint conditions and resolve TP more effectively.
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Computer Engineering. 2011, 37(16): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2011.16.067An Intelligent Wheelchair(IW) control system based on an embedded system is developed to achieve vision navigation by tracking marked-line economically and effectively. In the system, image data compression technology is used to solve the limited resources and the restricted running speed of embedded system, an adaptive threshold extraction algorithm for marked-line is proposed to realize threshold extraction in different light conditions and a fuzzy Proportional-Integral-Derivative(PID) control algorithm is introduced to implement stability control for IW path tracking. Meanwhile, technology fusion is adopted to ensure the safety of IW operation by combining with other technologies such as ultrasonic obstacle avoidance and manual operation intervention. Experimental results show that the IW operates safely and stably under the different environments.
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Computer Engineering. 2011, 37(16): 200-201. https://doi.org/10.3969/j.issn.1000-3428.2011.16.068On the basis of the Non-negative Sparse Coding(NNSC), considered the sparse measure constraint of feature basis vectors and the locality of features, a novel NNSC model based on localized features is proposed in this paper. This NNSC model utilizes the optimized method that combines the gradient and multiplicative algorithm to learn the feature coefficients, and only the gradient algorithm to learn feature vectors. Using this NNSC model to test the feature extraction process of palm images, and compared with the NNSC model and Localized Non-negative Matrix Factorization(LNMF), experimental results show that the model can extract image features efficiently and has quick convergence speed, as well as can model the sparse coding strategy used by the primary visual system in dealing with the nature processing. This further proves that the NNSC model proposed is feasibility and practicality in the theoretical research.
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Computer Engineering. 2011, 37(16): 202-205. https://doi.org/10.3969/j.issn.1000-3428.2011.16.069From the perspective of probability density function, Parzen window estimation is adopted to estimate the probability density distribution of the overall samples. A novel Maximum A Posteriori(MAP) classification method based on Parzen kernel estimation which shows higher performance in the multi-way classification is proposed by introducing kernel method and the Parzen window method. It is not necessary to consider the specific distribution of the sample data in this proposed method, but the reliability for the classification is obtained and the evidence for uncertain reasoning is also available. Experimental results of the three international standard UCI data sets and three facial image data sets show that the method has better classification effect.
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Computer Engineering. 2011, 37(16): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2011.16.070To improve the computer’s processing capacity on Chinese information, and do better shallow parsing, this paper presents a recognition method of Chinese phrase structure based on Maximum Entropy(ME). The Mutual Information(MI) among the phrases is proposed to achieve boundary prediction of the sentences structure, and the ME model is used to set up atomic and composite templates, selects more effective features for constituting the final feature set. The identification of phrase structure is completed by using the ME method, and good precision and recall are proved in the ME model based on MI by the practical experiment.
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Computer Engineering. 2011, 37(16): 209-211. https://doi.org/10.3969/j.issn.1000-3428.2011.16.071Feature level fusion and pixel level fusion are combined in order to obtain better fusion effect. Contourlet transform is used to decompose the source images into high-frequency subimage and low-frequency subimage. For the low-frequency subimage, Canny operator is used to take an edge detection and get an edge feature image. The edge feature image is taken as the input of intersecting cortical model, the fusion is made according to the number of neurons fire. For the high-frequency subimage, the energy coefficient matrix is used to make a fusion, and multi-focus clock images and CT, MRI images are used to experiment to the proposed method, entropy, mutual information and average gradient are taken as the fusion evaluation index. Experimental result shows the algorithm is superior to traditional fusion algorithm.
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Computer Engineering. 2011, 37(16): 212-214. https://doi.org/10.3969/j.issn.1000-3428.2011.16.072This paper proposes a shape retrieval method of animation image material by decomposing the contour and promote the Hausdorff distance. The materials are pre-processed in order to get the point aggregate of closed boundary, and the images are normalized by using the axis of least inertia of the area of the closed boudary. It decomposes the contour by corner detector, gets the same number of the points from each arc in order to descript the characteristic of the cartoon characters, measureing the distance of the sample by weighted housdorff distance. Experimental results show this method has higher retrieval precision, compared with existent methods.
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Computer Engineering. 2011, 37(16): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2011.16.073Due to the node resource constraints in Wireless Multimedia Sensor Networks(WMSNs), this paper proposes a Walsh-Hadamard based adaptive distributed image compression algorithm. According to accurate channel state estimating and adaptive quantization table, it ensures image quality to meet the application with a higher compression ratio. Simulation results show that the algorithm can extend the network life cycle in resource-constrained nodes deployed in dense WMSNs.
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Computer Engineering. 2011, 37(16): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2011.16.074In this paper, a new method of fractal algorithm combined with the quadtree algorithm is introduced to generate random dynamic terrain. Combined with midpoint displacement method and quadtree recursive partitioning algorithm, terrain generation is optimized. Simplified visibility culling strategies and data storage approach of triangle fans are used. Crack and popping problems are sovled in the terrain generation process. Texture blending technique are used to implement terrain rendering of the level of detail model. By this algorithm implementation and optimization, under the premise of guaranteeing that it is in a certain terrain visual realism effect, this method reduces expenses and achieves the purpose of improving real-time rendering speed.
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Computer Engineering. 2011, 37(16): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2011.16.075This paper proposes an image fusion method based on numerical differentiation. The classical calculation for gradient, difference of neighboring pixels is originally replaced by numerical differentiation, an accurate resolution for derivative of discrete data. The obtained image gradients are used in the fusion model based on Partial Differential Equation(PDE) so as to improve the numerical scheme based on PDE. Results of comparison experiments on improved method and former method show that the quality index and image convergence of fused image obtained by new method is improved.
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Computer Engineering. 2011, 37(16): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2011.16.076This paper proposes a method of emotional classification of the house-designing image based on color feature. A relationship model is built between the color features and emotional semantics based on the perceptual understanding of color. It uses the house- designing image as data, and the classification of house-designing image is performed by the extraction of global and local color feature combine with the classifier based on the Radial Basis Function Neural Network(RBFNN). Experimental results show the availability of the classification.
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Computer Engineering. 2011, 37(16): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2011.16.077The limitation of actual environment causes the problem of uneven brightness and noise in the image when capturing images of the crack detection by employing the technology of machine vision in large penstock. The results of crack detection and extraction are seriously affected if the uneven brightness and noise are not dealt with properly. To settle this problem, a new image enhancement method based on linear spatial filter and wavelet transformation is proposed. This method uses the linear spatial filter to improve the uneven brightness phenomenon. The wavelet transformation is employed to remove the noise and enhance the details. The comparison and analysis of several methods are presented. Experimental results show the method is superior to traditional image enhancement methods and is suitable for real-time processing.
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Computer Engineering. 2011, 37(16): 230-231. https://doi.org/10.3969/j.issn.1000-3428.2011.16.078In view of the characteristics of infrared image, the veracity is not good when the commonly used threshold is used in infrared image segmentation. A 3D Otsu method based on gray level-average gray level-gradient histogram is proposed. The sparse matrix and improved Particle Swarm Optimization(PSO) algorithm are used to search for the segmentation threshold. An effective method that identifies premature stagnation is embedded to PSO. The operation velocity is improved and the veracity is better. Experimental results demonstrate the algorithm can segment infrared images quickly and effectively.
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Computer Engineering. 2011, 37(16): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2011.16.079This paper applies Total Variational(TV) model to inpaint image, proposes an optimization transformation method for image inpainting. It uses an optimization transformation technique which involves replacing their univariate functional of TV model by a bivariate functional by adding an auxiliary variable. The Chambolle’s projection algorithm and alternating minimization method are employed in solving the model. Experimental results show that compared with the algorithm of solving TV model based on gradient descent method, the efficiency and quality of inpainted images by the proposed method is improved.
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Computer Engineering. 2011, 37(16): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2011.16.080In the hierarchical control system, intelligent control devices place in the pot performance layer. The devices receive the user orders or program from the upper class control devices by intelligent control devices. These orders and user program need converse, so they are carried out by Micro Control Unit(MCU) of intelligence node. It puts forward the program design method, though the analysis of the user program function, type, phrase and sign, made use of the principle of limited status machine. The program which can be explained and executed is as a UCOSⅡtask and constituted the intelligent control software with other task programs. Through the test, the result proves that the explain machine can explain and execute the user programs correctly, it also can independently execute the control task based on the spot environment.
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Computer Engineering. 2011, 37(16): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2011.16.081Real-time Ethernet for Plant Automation(EPA-RT) technology can not meet the actual needs of high-performance motion control. To resolve the problem, this paper uses fast schedule algorithm and precise synchronization technology of Fast Real-time Ethernet for Plant Automation(EPA-FRT) technology to achieve better real-time performance and higher synchronization accuracy. Six-layer communication model and two-layer network structure are analyzed. Performance test result of EPA-FRT system shows that the communication cycle time is less than l ms and the synchronization deviation is less than 1 μs, so the EPA-FRT system can meet the demands of high-performance motion control system.
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Computer Engineering. 2011, 37(16): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2011.16.082For the problem of data lose in structural healthy monitoring system for the bridge, Granger causality test is introduced to calculate the casual relation between two sensors, and select the sensor signal of larger relation as input vector for extreme learning machine to recover the lost sensor signal data. The proposed data recover algorithm is tested in the case of the bridge structural health monitoring system, and the simulation results indicate the algorithm is correct and efficient in theory and practice with the performance index for mean square error and largest error absolute value, compared with Back Propagation(BP) network and Least Squares Support Vector Machine(LS_SVM).
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Computer Engineering. 2011, 37(16): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2011.16.083This paper presents a high-performance and high-secure embedded virtual machine model for OKL4. Based on the model, a virtualization solution for μC/OS-II on OKL4 is designed, and it involves CPU virtualization design and memory virtualization design. The construction process of the virtual hardware abstraction layer is detailed. The method of porting μC/OS-II to the virtual hardware abstraction layer is presented. Test results on Hi3611 smart phone developing board show that the virtualization solution is correct.
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Computer Engineering. 2011, 37(16): 247-250. https://doi.org/10.3969/j.issn.1000-3428.2011.16.084Aiming at the real-time requirement of the biped robot BHBIP-1, this paper designs and realizes a three-layer humanoid robot distributed control system, including the master layer based on PC104, the CAN bus communication layer and execution layer. The design of hardware and control software of the host computer and joint position servo controller are given. Experimental result proves that the distributed control system fits for BHBIP-1 control environment and matches the requirements of walking stably.
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Computer Engineering. 2011, 37(16): 251-253. https://doi.org/10.3969/j.issn.1000-3428.2011.16.085This paper does a research in the technology of handover and routing. It analyzes the problems of losing packets in rapid handover and inaccurate routing. It also proposes dual-channel asynchronous switching scheme and Optimized Link State Routing(OLSR) scheme based on bandwidth. It does some field test for the feasibility of the proposal. Results show that the wireless communication system using above-mentioned scheme has a very good performance in some aspect such as bandwidth and packet loss rate, and it sets a good example for the next project implementation.
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Computer Engineering. 2011, 37(16): 254-255. https://doi.org/10.3969/j.issn.1000-3428.2011.16.086This paper takes Alpha processor as the platform, and migrates the system simulation software of QEMU to Alpha platform, so that the virtual machine on system can perform Linux operating system based on x86 architecture to achieve Alpha processor compatible x86 applications. Performance test is performed on virtual machine. Through the statistics of code inflation rate, a restricted virtual machine performance instruction type, is found to provide reference for virtual machine performance optimization.
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Computer Engineering. 2011, 37(16): 256-259. https://doi.org/10.3969/j.issn.1000-3428.2011.16.087Aiming at the poor composability of equipment battle damage composable model, the manufacturing method for equipment battle damage composable simulation system based on metamodel is presented. The binary oppositional structure of equipment battle damage model is designed by analyzing construction elements for equipment battle damage composable model, the metamodel decision-making method is presented referring to the basic metamodeling process, and the equipment battle damage simulation system based on metamodel is implemented, including the battle damage mechanism metamodel database, the part battle damage metamodel database and the equipment battle damage metamodel database. Simulation results indicate that the system is able to assemble the equipment battle damage models of different levels together effectively, and realize the compositive simulation results output for multi-resolution models.
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Computer Engineering. 2011, 37(16): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2011.16.088This paper proposes visual simulation platform for flight control system, it designs system overall framework by parallel computation thoughts it realizes the parallel computation for flight dynamics system and flight control system through multi-programming technology of OpenMP and Single Program Multiple Data(SPMD). The platform can load various kind of flight controller, flight dynamic model of aircraft and digital map to simulate, and it can show simulation result in form of numeral, simulation curve and 3D animation. The feasibility of this platform is validated by the flight control system of Beaver, and result show that this platform has the merits of visual modeling, high efficient simulation, easy to expand and strong commonality.
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Computer Engineering. 2011, 37(16): 263-266. https://doi.org/10.3969/j.issn.1000-3428.2011.16.089Traditional method of water transparency measurement is field-oriented method, and it can be easily affected by objective factors, such as the measure time and weather. According to photometry, this paper designs a transparency measuring sensor by using laser module and photocell. By using this sensor, this paper designs a transparency measuring system which is based on general packet radio service. Using the water transparency formula of the Tai Lake, this system is fulfilled the measurement of a certain area of the Tai Lake. Results show that this method is feasible, the sensor is accurate and reliable, the entire system is stable and can provide a basic advice for environment department.
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Computer Engineering. 2011, 37(16): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2011.16.090Aiming at the current situation that pays much attention to support capability evaluation while pays little attention to seeking out the weakness link of support capability, this paper puts forward a kind of method to ensure the support capability weakness link through getting the weakness degree of each index. The weakness degree is determined by index margin space and weight, by making use of the Principal Component Analysis(PCA) to ensure the weight of each index and optimizing the index margin space by applying the set pair analysis. Example indicates that the method put forward can be used to obtain the optimum amelioration project for the weakness link and station the support resources reasonably.
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Computer Engineering. 2011, 37(16): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2011.16.091The diversity of virtualization products brings the complexity of virtual systems unifying management and scheduling. This paper proposes a unified virtual systems management modeling based on Common Information Model(CIM), which solves the unified management issues of heterogeneous virtualization platform, supports the standard service provider, implements the resource subscription module and self-management ability. Meanwhile, by using and modifying of some open source projects, the model is implemented, and it shows that the model has good ability of the unified management of virtual systems as well as flexibility and dynamic extensibility.
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Computer Engineering. 2011, 37(16): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2011.16.092This paper proposes an Electrocardiogram(ECG) monitoring system software and a series of self-detection algorithm for computer analysis of ECG, which are separately based on the Internet of Things(IOT) technology and the wavelet transform, and introduces the application of Wireless Sensor Network(WSN) for ECG monitoring. The functions of this system software include that it can realize ECG data transceiver, data memory, waveform display and communication management by using servers and Personal Digital Assistant(PDA). Experimental results show that this system software can make computer and PDA display the ECG waveform in a real-time way. Compared with MIT-BIH database annotation, the false detection rate of this algorithm which goes trough the Matlab simulation test is just 0.89%.
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Computer Engineering. 2011, 37(16): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2011.16.093To avoid “Wobbling” and “Pieces” phenomena generated by 32 bit representation of Graphics Processing Unit(GPU) when space scene visualization with high numerical range is implemented, a draw solution with grouping and gradation is put forward. The objects in scene are classified as a big entity and a small entity based on reasons of phenomena above. Objects are grouped according to relations between objects and characteristic of space scene. The draw method for objects in group is designed. Experimental results show that the realization of space scene visualization image based on the method introduced above is correct and stable.
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Computer Engineering. 2011, 37(16): 279-281. https://doi.org/10.3969/j.issn.1000-3428.2011.16.094This paper builds the multi-product model and single-product model to accurately measure the seller’s overall credit and partial credit. On this basis, it proposes seller filtering oriented popular credit model. It can filter substandard seller and improve the recommendation accuracy. It introduces evaluator-credibility, price fluctuations, penalty factor, in order to improve the accuracy of the credit value. Simulation results verify the model’s effectiveness to prevent credit fraud.
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Computer Engineering. 2011, 37(16): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2011.16.095In order to meet the demand for real-time QRS wave detection of multi-lead ECG monitor, a simple real-time QRS wave detection algorithm of multi-lead Electrocardiogram(ECG) signals is proposed. The original ECG is passed through a notch filter and a low-pass filter, QRS wave is detected by each lead in accordance with the single-lead decision rule, the final result is given by decision fusion. The algorithm is tested by using St. Petersburg INCART 12-lead arrhythmia database, result shows that its average recognition rate is 99.88% and accuracy rate is 99.73%.
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Computer Engineering. 2011, 37(16): 285-287. https://doi.org/10.3969/j.issn.1000-3428.2011.16.096Aiming at the shortage that the positioning accuracy of the VIRE algorithm is low, the improvement algorithm is introduced. It includes the nonlinear interpolation algorithm, and the dynamic threshold setting as well as the self-correcting of tags in the dim map. The indoor positioning system based on reference tag is constructed. Then the interface software is built. Experimental results show that the improvement VIRE algorithm improves the positioning accuracy and the positioning stability in complex environments significantly without adding reference tag numbers.
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Computer Engineering. 2011, 37(16): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2011.16.097In this paper, the solution of matching service from vertical direction is presented for the problem of automatic transform from logic model to physical model in data-oriented Business Process Management System(BPMS). Artifact is described in XML, and based on it, the formal description of the Artifact-centric business process model, ArtiFlow, and the definition of logic service are proposed. An algorithm for abstract logic service from ArtiFlow process is presented. Based on the definition of embedding of XML trees, the matching algorithm from logic service to physical service is provided.
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Computer Engineering. 2011, 37(16): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2011.16.098This paper studies the exclusive Java virtual machine of Android——Dalvik, expounds the interpreter, the Java native interface call bridge, and C library for transplantation and optimization based on CK610 architecture. Based on the distribution mechanism of the Dalvik’s interpreter, it puts forward an improved Threaded distribution mechanism, and achieves an architecture customized MInterp interpreter of CK610, which proves to enhance the virtual machine to run rate 1 times above.
2024
Volume 50 No 4
Volume 50 No 4
(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