05 January 2012, Volume 38 Issue 01
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Computer Engineering. 2012, 38(01): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2012.01.001
In order to overcome the limitation of literal matching and lacking semantic concept of the traditional keyword extraction algorithm, this paper presents a Semantic-based Keyword Extraction(SKE) algorithm for Chinese text. It uses semantic feature in the keyword extraction process and constructs word semantic similarity network and uses betweenness centrality density. Experimental results show that compared with the statistic based keyword extraction algorithm, the keywords SKE algorithm extracted are more reasonable and can represent more information of the document’s topic, and the SKE algorithm has a better performance.
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Computer Engineering. 2012, 38(01): 5-9. https://doi.org/10.3969/j.issn.1000-3428.2012.01.002
According to the problems that data exchange between servers of different types, load balance and schedule, serial processing of user data, and performance of server in relatively complex situations of user number and data type, this paper proposes a method for server performance evaluation and optimization based on multi-tier cache structure. This method starts from the functional structure of network server system, divides the server into multi-layer structure according to the function, then optimizes the corresponding part of server by different caching strategy of nodes. Experimental results show that the optimized server can make good use of system resources and improve server performance.
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Computer Engineering. 2012, 38(01): 10-13. https://doi.org/10.3969/j.issn.1000-3428.2012.01.003
Trust degrees of Certificate Authority(CA) are ignored in present Public Key Infrastructure(PKI). In modularized trust management model, complete subjective logic trust evaluation model is proposed, with direct trust, recommendation and consensus operators to establish, transfer and calculate trust, and degeneration operator to simulate trust attenuation. The dependent series-parallel graphs are analyzed. The methods of subjective logic are testified to compute the trust value precisely and to improve the creditability of PKI system.
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Computer Engineering. 2012, 38(01): 14-18. https://doi.org/10.3969/j.issn.1000-3428.2012.01.004
In order to execute Java bytecode of CISC structure in hardware, instruction set for 32-bit embedded real-time Java platform JPOR-32 (Java Processor Optimized for RTSJ) is designed. By analyzing the function and implementation principle of Java bytecode in the JVM specification, variation of signals and data of Java processor data path is set up. Complex instructions are executed using micro-instructions and simple instructions are executed directly, so that JPOR-32 set of instructions has a RISC feature. The results of Java code execution verify the correctness and Worst Case Execution Time(WCET) predictability of the instruction set.
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Computer Engineering. 2012, 38(01): 19-23. https://doi.org/10.3969/j.issn.1000-3428.2012.01.005
Aiming at the fairness problem of cognitive radio spectrum allocation, this paper presents a modified color sensitive graph coloring algorithm. According to user spectrum efficiency, the algorithm generates weight about spectrum allocation, corrects color sensitive graph coloring algorithm through the weight, and makes a certain improvement in spectrum allocation. Simulations are conducted to compare this method with color sensitive graph coloring algorithm. Results show that the modified graph coloring algorithm decreases total network efficiency, but it has higher performance in the fairness of using spectrum.
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Computer Engineering. 2012, 38(01): 24-28. https://doi.org/10.3969/j.issn.1000-3428.2012.01.006
This paper presents an epidemic propagation model based on Agent dynamical network to study the dynamical behaviors of epidemic transmission. The model extends traditional epidemic spread SIR model, describes the post-infection process of epidemic by different individual states. In order to adapt to the social network of epidemic transmission, this paper constructs the dynamical social network based on two-dimensional regular network by adding individual autonomy of mobility, considers the effects of heterogeneity and protection measures on the dynamics of transmission. Simulation results show the model fairly reflects the effects of dynamic social network and individual adaptive behaviors on the spread of the epidemic, and it is almost consistent with the reality condition.
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Computer Engineering. 2012, 38(01): 29-32. https://doi.org/10.3969/j.issn.1000-3428.2012.01.007
This paper presents a data exchange model of Electronic Flight Bag System(EFBS). This model uses star-type logic structure to implement data transfer, and exchanges the message through data exchange components and central content management elements, then implements EFBS message exchange through a data exchange procedure designed with XML. A data integrity exchange procedure and an integrity check mechanism of EFBS are presented. In this mechanism, the sender generates digital signatures with DSA algorithm and the text summary is calculated by SHA-1 algorithm. At the receiver, the data integrity checking operation is conducted through digital signature verification consequently. Experimental results demonstrate the effectiveness and feasibility of this EFBS data integrity checking mechanism.
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Computer Engineering. 2012, 38(01): 33-36,41. https://doi.org/10.3969/j.issn.1000-3428.2012.01.008
The existed trusted remote attestation method lacks description of dynamic of remote attestation, and it is not enough theoretical research on how attestation subject/guest interactions influence the trustworthiness. This paper presents a double integrity trusted attestation model. The model introduces the concept of trustworthiness, defines trustworthiness attributes and the rules for establishing trust states. According to this model, a trusted attestation system is designed. It analyzes the different methods about attesting the integrity of attestation subjects/objects.
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Computer Engineering. 2012, 38(01): 37-41. https://doi.org/10.3969/j.issn.1000-3428.2012.01.009
In Long Term Evaluation(LTE) system, Mobility Load Balancing(MLB) and Mobility Robustness Optimization(MRO) may conflict with each other when they both adjust handover parameters to optimize their respective objects, and consequently system performance degrades. A coordination mechanism embedded in the MLB is proposed to alleviate the impact of conflict problem between MLB and MRO by mobility robustness supervision, handover edge labeling and parameter rollback. Simulation results show that this mechanism can immediately prevent negative handover parameters adjustments by MLB, and decrease the number of mobility problems caused by MLB.
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Computer Engineering. 2012, 38(01): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2012.01.010This paper focuses on the multi-tenancy problem in Business Process Management as a Service(BPMaaS) based on the analysis of Software as a service(SaaS) technology. It proposes a resource isolation and sharing method based on middleware to support multi-tenant sharing one application instance so as to improve the usage of computing resources. Application Programming Interfaces(APIs) are provided to ease multi-tenant BPM application development. Verification is conducted using JUnit through a real case, and the result improves the feasibility of this method.
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Computer Engineering. 2012, 38(01): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2012.01.011This paper presents an approach to build a reverse engineering tool, named Halo, for Java projects on the Eclipse platform, a popular integrated development environment; it describes the design ideas and the implementation steps of the Halo tool, which include how to extract model information from program source code using abstract syntax trees, and how to transform, using the adapted Sugiyama layout algorithm, the extracted logical model to the UML class diagrams that are suitable for developers to read. It also discusses some technical difficulties in building the Halo tool and gives the corresponding solutions. Experimental results show that the Halo tool is able to meet the requirements of developers for RE.
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Computer Engineering. 2012, 38(01): 48-50,54. https://doi.org/10.3969/j.issn.1000-3428.2012.01.012Kernel methods for relation have the implicit representation of feature spaces which can’t distinguish useful feature from useless. As a result, it introduces noise and affect performance. Aiming at this problem, this paper presents entity relation extraction based on the feature of subtrees. The proposed method uses subtree mining and feature selection to get the more useful subtrees, and the feature vector is constructed on them for categorization. Experimental result in Chinese language database shows that the proposed method for entity relation extraction is effective.
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Computer Engineering. 2012, 38(01): 51-54. https://doi.org/10.3969/j.issn.1000-3428.2012.01.013In order to improve the performance of the weaving efficiency which is one of the most important efficiency factors for Aspect-oriented Programming(AOP), based on current research results that raise weaving-on-demand, weaving history mechanisms and weaving approach implementation based on log, this paper presents a log-based incremental weaving mechanism implementation. This method gives an aspect storage structure, based on this structure it can quantitatively describe current weaving state, computes the change of weaving state, and achieves incremental weaving to improve the efficiency of weaving.
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Computer Engineering. 2012, 38(01): 55-58,61. https://doi.org/10.3969/j.issn.1000-3428.2012.01.014For data traffic flow is too large to store the entire data stream or on its scan times and other issues, through the research of algorithms on mining frequent patterns that are proposed, this paper proposes an algorithm on mining frequent patterns over data stream based on Landmark window, named DSMFP_LW. DSMFP_LW has major features as follows: namely single streaming data scan for counting pattern’s information, extended prefix-tree-based compact pattern representation, and incremental update of data. Experimental results show that DSMFP_LW algorithm has better utilization of time and space efficiency. In addition, it outperforms the well-known algorithm Lossy Counting in the same streaming environment.
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Computer Engineering. 2012, 38(01): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2012.01.015For discovering association rules based on graph can generate a large number of candidate itemsets, an improved algorithm is proposed. The improved algorithm combined the top-down and bottom-up search in all search process, and sorted the frequent 1-itemset on support degree and count the support of maximal superset of frequent k-itemsets. It utilizes direct graph and Apriori property to prune the redundant candidate itemsets. Experimental result shows that the improved algorithm reduce the number of candidate itemsets when the minimum support is small and the performance is improved.
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Computer Engineering. 2012, 38(01): 62-64,67. https://doi.org/10.3969/j.issn.1000-3428.2012.01.016Combining the different quality and management requirements of softwares, a Software Configuration Management(SCM) method is designed. In order to solve the efficiency problems in construction, management and maintenance of software configuration component library, this paper proposes a component classification method based on priority-facet, PF-CCM, which causes it being suitable optimization component retrieval and inquiry. Unified the three kinds of component retrieval mechanism, index, key word and facet, an optimized matching algorithm with pruning, POMA is introduced, which can sort the inquiry results according to the priority of facets. Experimental result shows that the POMA method can enhance the inquiry efficiency.
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Computer Engineering. 2012, 38(01): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2012.01.017Checking the consistency of the decision matrixes is essential but becomes very difficult in a Fuzzy Analytic Hierarchy Process(FAHP)-based Web quality assessment due to the fuzzy logic. Two approaches are analyzed in the paper, which are the value substitution with maximum degree of membership and the least-squares-method-based consistency checking. The fuzzy pair-wise comparison matrix meets the consistency requirements by applying the two methods based on key quality data. The study indicates that two techniques can simplify the discrimination of the consistency of fuzzy pair-wise comparison matrixes and ensure the rationality of the assessment and the soundness of decision result. The latter approach is more applicable.
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Computer Engineering. 2012, 38(01): 68-70,73. https://doi.org/10.3969/j.issn.1000-3428.2012.01.018Disassembly is the foundation of code analysis, code detection and code instrumentation, by translating binary code into symbol form. Disassembly technology based on static analysis and dynamic emulation is presented in this paper, in order to improve the accuracy and coverage of code disassembly. Based on the static disassembly algorithms, dynamic identification algorithm of basic block is constructed by using code emulation environment, and the code disassembly is refined by monitoring the execution paths of code. Test results show that the technology is effective.
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Computer Engineering. 2012, 38(01): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2012.01.019In order to reduce the cost of non-incremental Java Virtual Machine(JVM) garbage collector, the paper proposes a stack-allocation based incremental garbage collection algorithm. It improves the Java stack frame and makes it support object storage. At the same time, the paper improves the division of heap space and reference tracking of the incremental garbage collection algorithm in order to reduce the uncertain pauses caused by garbage collection. Experimental results show that this algorithm can reduce the frequency and duration of pauses, and enhance the speed of operation.
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Computer Engineering. 2012, 38(01): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2012.01.020In view of the present situation that science and technology information resources scatter in grass-roots institutions, this paper proposes an online escrow system based SaaS mode for resources of science and technology information. It uses complete isolation of multi-tenancy data structure and more distributed database agent strategy to divide the system architecture into the application layer database scheduling layer and database layer. It designs the core mechanism including more multi-tenancy data structure and distributed data agent system. Experimental results show that the system can manage technology information resource from multi-tenancy online and achieve information resource gathering and trusteeship.
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Computer Engineering. 2012, 38(01): 77-80. https://doi.org/10.3969/j.issn.1000-3428.2012.01.021According to the possible difference of Linear Frequency Modulation(LFM) signal parameter between repetition and Signal of Interest (SOI), the complex ambiguity function and cross correlation function when the deviation between repetition and SOI is existed are given. The influence of phase difference, frequency offset and chirp rate offset on performance analysis of correlation detection is analyzed. The conclusion indicates phase difference has no effects on detection and the detection probability decreases with the increase of frequency offset and chirp rate offset.
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Computer Engineering. 2012, 38(01): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2012.01.022Combining advantages of cyclic spectrum sensing with advantages of relay cooperative sensing, this paper proposes cyclic spectrum detection method in fading channels. Considering different channels’ channel gain and correlation between cognitive users jointly, the two users cooperative channel model is constructed, and test statistic expression is also given. Based on the above results, it discusses relay cooperation of multi-user network, and it makes detection performance simulation. Simulation results show, when the false alarm probability is small, detection probability and detection agility through relay cooperation both improve significantly, and agility gain decreases with the distance between two cognitive user increases.
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Computer Engineering. 2012, 38(01): 84-86,89. https://doi.org/10.3969/j.issn.1000-3428.2012.01.023The network traffic has the features of relevance and nonstationarity. In order to make the traffic flow prediction model have the features of adaptability and correlation, this paper puts forward a new method by time point to create the model, and the time series combined with flow series. And it involves multivariate linear regression to evaluate arguments, uses the EWMA to process arguments and establishes the multivariate linear AR model. Experimental results show that compared with the AR model and ARMA model, the multivariate linear auto regression model is more accurate.
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Computer Engineering. 2012, 38(01): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2012.01.024To solve the problem of energy hole in communication that caused by multi-hop routing in Wireless Sensor Network(WSN), this paper proposes a hybrid routing tree algorithm based on ring topology. That creates a mixed routing tree with minimum cost, changes the method of route communication between single hop and multi-hop, and balances energy consumption. Simulation results show that, this algorithm is effective to solve the problem of energy hole and also can prolong the lifetime of networks at utmost.
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Computer Engineering. 2012, 38(01): 90-92,95. https://doi.org/10.3969/j.issn.1000-3428.2012.01.025Focusing on the requirement of low cost and high accuracy in Wireless Sensor Network(WSN), an improvement method of weighted centroid localization algorithm which uses the Particle Swarm Optimization(PSO) to optimize is introduced based on Received Signal Strength Indicator(RSSI). The new algorithm is easy to achieve and has a few parameters to adjust. Through multiple iterative optimizations, it can improve the localization accuracy. The errors of RSSI distance measurement and localization of each beacon node can be got by measuring the distance and localization between beacon nodes. Simulation result shows that the localization accuracy of the new algorithm is significantly superior to that of centroid localization algorithm and weighted centroid localization algorithm.
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Computer Engineering. 2012, 38(01): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2012.01.026Fault detection of deployed sensor network is difficult due to constrained resources. A fault detection method based on anomaly task operational log is proposed. Behavior-state model of sensor nodes is devised through analyzing execution characteristics of the node program. The model combining with pre-deployment test records and chi-square test is used for fault detection during post-deployment. Experimental results show that the method can effectively detect the unknown type of fault. The communication storage and computing cost are small.
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Computer Engineering. 2012, 38(01): 96-98,110. https://doi.org/10.3969/j.issn.1000-3428.2012.01.027Aiming at the application characteristics of wireless Home Area Networks(HANs), this paper presents a K-means-based clustering algorithm for wireless HANs. The algorithm sets the optimal number of clusters in LEACH as the initial input parameters, and realizes the centralized and on-demand clustering on base station in home area networks, which makes use of Silhouette value to evaluate the optimal clustering. Experimental results show that this algorithm can get good clustering quality in wireless HANs simulation scene.
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Computer Engineering. 2012, 38(01): 99-101,113. https://doi.org/10.3969/j.issn.1000-3428.2012.01.028This paper presents a 2-Level Flow Adjustment(2-LFA) mechanism using Autoregressive Integrated Moving Average(ARMA) flow forcasting model. Nodes can periodically forecast the next phase’s flow according to this model, and compare the value to the defined flow thresholds, and make the decision on how to transmit packages. The over-flow node avoids its fast death by establishing a temporary virtual circuit between low load brother node and high load son node. Simulation result verifies that 2-LFA can considerably prolong the lifetime of bottle-neck nodes and shorten the lifetime difference among the whole network, compares to 1-Level Flow Adjustment(2-LFA) and none adjustment mechanism, balances the energy consumption at the same time.
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Computer Engineering. 2012, 38(01): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2012.01.029In order to cut down the energy consumption of the nodes and extend the lifetime of Wireless Sensor Network(WSN), a power adaptation routing algorithm for WSN based on Ant Colony Optimization(ACO) is proposed. It takes the transmission direction of the nodes, residual energy and distance between nodes into account when ants find paths. After finding an optimal path, the transmission power of the nodes is adjusted according to the distance between two adjacent nodes to optimize the energy consumption. Simulation results indicate that the algorithm can effectively save network overhead and prolong the network lifetime when the nodes are distributed non-uniformly.
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Computer Engineering. 2012, 38(01): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2012.01.030In view of the situation that different institutions may adopt different coordinate system of geometric objects including point and circle, this paper is the first to propose and design two protocols for the point-circle relation determination problem and the circle-circle relation determination problem based on the two protocols for privacy preserving coordinate transformation and distance measure of different coordinates. Their correctness, security and efficiency are analyzed. Analysis shows that problem of determining the relative position of point-circle and circle- circle is successfully solved in the paper.
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Computer Engineering. 2012, 38(01): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2012.01.031An authentication and key agreement scheme, which suffers from the replay attacks and dos attacks, preserving the privacy of secret key is proposed. For improving their scheme to ensure robust security for the mutual authentication process, it proposes an efficient authentication scheme using smart cards, which is based on elliptic curve discrete logarithm problem and a secure one-way hash function. It defends replay attack and mitigates do attack that could be launched against other related previous schemes because it is timestamp-based, and requires less computational cost. The analysis result shows this scheme is secure and efficient.
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Computer Engineering. 2012, 38(01): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2012.01.032New construction of forward secure threshold signature scheme based on the technique of polynomial secret sharing and the concept of forward security is proposed. The new scheme integrates the round-optimal distributed key generation and the concept of proactive security, and improves the efficiency of key update. This scheme outperforms all previous schemes in terms of communication rounds in the signature algorithm. Analysis result shows that the scheme has high computation efficiency and it is forward secure.
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Computer Engineering. 2012, 38(01): 114-116,119. https://doi.org/10.3969/j.issn.1000-3428.2012.01.033To the problem of trust models based on D-S evidence theory can not combine evidence information reasonably, a new D-S combination rule, IDSECR, is established by allotting the conflicted probability again and introducing weight coefficients. It establishes a trust model by IDSECR, Trust Model Based on D-S Evidence Theory for P2P networks(DSETTM), which solves the problem of not invalidly aggregating incompatible recommendation information in the traditional trust models. Simulation experimental results show that DSETTM has a much higher transaction successful rate under attacking of different types of malicious peers.
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Computer Engineering. 2012, 38(01): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2012.01.034This paper researches on algebraic immunity of concatenated function, uses concatenation construction method to construct Boolean function with good cryptographic properties. It discusses the algebraic immunity of Boolean function and . The upper bounds and the lower bounds of their algebraic immune degree are gotten. Meanwhile, a sufficient condition under which their upper bounds are obtained is presented respectively. Compared with other researches, the sufficient condition is easily satisfied and is effectively determined.
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Computer Engineering. 2012, 38(01): 120-121,124. https://doi.org/10.3969/j.issn.1000-3428.2012.01.035This paper presents a security analysis of a threshold signature scheme with proxy. It finds that the scheme can not meet the strong unforgeability because of the group private-key setting incorrectly. To overcome the original scheme’s weaknesses, this paper proposes an improved scheme. The new scheme can resist internal attack and external attack by increasing the application of the hash function in the group private-key setting and changing the part of signature form. The security analysis proves that the improvement scheme is secure.
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Computer Engineering. 2012, 38(01): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2012.01.036In order to improve the efficiency and enhance the security of mutual authentication in wireless network. Based on Elliptic Curve Discrete Logarithm Problem(ECDLP), this paper proposes an efficient anonymity authentication scheme based on smart card in wireless network. It demonstrates that computation is efficient, with only one hash operation, two symmetric encryptions and one symmetric decryption for a mobile node. Analysis shows that it is immune to various known types of attacks while achieving identity anonymity.
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Computer Engineering. 2012, 38(01): 125-126,129. https://doi.org/10.3969/j.issn.1000-3428.2012.01.037In order to improve the security and reliability of computer systems and networks, this paper proposes an improved computer multi-virus propagation model with user awareness, and the influence of both human and objective factors is comprehensively considered. Furthermore, stability analysis and experimental simulation are adopted, that virus-free equilibrium is globally stable and virus-endemic equilibrium is locally asymptotically stable are proved. Simulation results show that in the model proposed in this paper the propagation of computer viruses can be effectively controlled by improving user awareness and reducing the frequency of new virus’s appearance.
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Computer Engineering. 2012, 38(01): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2012.01.038Threshold signature methods mostly have very large and dynamic groups, they don’t apply to Mobile Ad-hoc Networks(MANETs). This paper presents an efficient threshold signature protocol for MANETs, which is proved secure based on the basic RSA assumption, and satisfies universal compsability security. Furthermore, the proposed protocol is proactive, providing both the “the secret key sharing” and “the partial secret key refreshing”. Security analysis result proves the high effectiveness of the protocal.
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Computer Engineering. 2012, 38(01): 130-131,134. https://doi.org/10.3969/j.issn.1000-3428.2012.01.039In view of some inefficient MapToPoint hash functions are used in existing threshold signature schemes. which cause these schemes to be very difficult to avoid the threats because of the hash functions many times use in the cryptography. A new threshold partially blind signature from bilinear pairings is proposed which combines the threshold signature and partially blind signature together. Analysis result shows that the new scheme only needs efficient common hash functions, it can improve the efficiency of the scheme and meet the merits of threshold and partially blind signature.
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Computer Engineering. 2012, 38(01): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2012.01.040Using the theory of the bilinear pairings on elliptic curve mapping and identity-based cryptography, this paper proposes a new identity-based threshold proxy signature scheme. The new scheme uses a method that a trusted private key generation center generates and manages private keys, avoiding complex problems of management that caused by using certificates. This paper carries out that the scheme satisfies the distinction, verifiability, strong unforgeability, strong recognizability, strong non-repudiation and analysis of other security features. It shows that the new scheme is secure and effective.
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Computer Engineering. 2012, 38(01): 135-136. https://doi.org/10.3969/j.issn.1000-3428.2012.01.041According to in-depth security analyzing of a proxy signature scheme with revocation by the use of timestamp, it points out that the malicious proxy signer can obtain a valid timestamp whatever the original signer revoked the delegation or not because the time-stamp issued by Authentication Sserver(AS) do not bind with the delegation of original signer. Pointing at the problems existed in the timestamp generation phase, this paper proposes a more efficient scheme with fast revocation, which solves the weaknesses of original scheme fundamentally.
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Computer Engineering. 2012, 38(01): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2012.01.042Aiming at the security problem of adaptive steganography, the analysis method based on Gaussian mixture model(GMM) of real image is proposed. Compared the stego random characteristic function of probability density function between the adaptive Spread Spectrum Image Steganography(SSIS) and the general non adaptive one under the condition that the total embedding intensity is equal, it demonstrates that the security of adaptive SSIS is higher than that of non-adaptive schemes. Analysis result shows that the method provides theoretical evidence for using adaptive scheme to improve statistical imperceptibility of steganography.
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Computer Engineering. 2012, 38(01): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2012.01.043This paper presents an iterated Tabu Search(TS) algorithm for the Binary Quadratic Programming(BQP) problem. The TS as the Local Search(LS) and a new perturbation strategy makes the search jump into a more promising area when TS falling into the local optimum. Experimental results show that the proposed algorithm can reach the best known solution on all the 30 large OR-library instances and comparisons with TS. Simulated Annealing(SA) and Memetic Algorithm(MA) demonstrate the competitiveness of the proposed algorithm.
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Computer Engineering. 2012, 38(01): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2012.01.044In view of face recognition with only one sample problem, this paper presents a method of face recognition based on virtual image. In order to enhance the classification information of single training sample, it first adds some virtual images generating from the given training image. By using Discrete Wavelet Transform(DWT), the low-frequency band is used as feature for recognition. Two-dimensional Principal Component Analysis(2DPCA) is performed on the low-frequency faces. Experimental results show that this method can filter the high frequency of informations which are caused by a expression change and little cover, and promote the recognition rate.
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Computer Engineering. 2012, 38(01): 146-147. https://doi.org/10.3969/j.issn.1000-3428.2012.01.045The Principal Component Analysis(PCA) is not the best method to extract features for recognition because the difference between different kinds is not considered. Aiming at this problem, a new face recognition algorithm based on PCA is proposed. It uses PCA reducing dimensions method to extract the individuality difference. A nearest neighbor classifier is employed to classify the extracted features. The method in the paper is evaluated on the ORL face image database, a series of experiments to compare the proposed approach with traditional PCA method. Experimental results demonstrate the efficacy of the algorithm.
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Computer Engineering. 2012, 38(01): 148-150. https://doi.org/10.3969/j.issn.1000-3428.2012.01.046In order to solve the imbalance between the data samples, this paper proposes a dynamic weighted semi-supervised fuzzy kernel clustering algorithm based on pairwise constraints, which incorporates both semi-supervised learning mechanism and the kernel function into traditional fuzzy clustering algorithm. Data in the original space are mapped to a high-dimensional feature space by Merce kernel functions, and an dynamic weight is assigned to each vector in the feature space. A modified objective function for fuzzy clustering is introduced in the feature space. A simple method is presented to determine the appropriate values for the kernel width. Theoretical analysis and experimental results testify that. the new algorithm has better clustering performance compared with other semi-supervised fuzzy clustering algorithms such as Pairwise Constrained Competitive Agglomeration(OCCA).
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Computer Engineering. 2012, 38(01): 151-153,156. https://doi.org/10.3969/j.issn.1000-3428.2012.01.047This paper uses the Empirical Mode Decomposition(EMD) method as the theoretical basis. A new method based on weighted similar waveform which can improve the end effects in the processing of EMD effectively. It uses the new method to denoise the Electroence- phalogram(EEG) signals. Simulation results based on the EEG database of California Institute of Technology show the improved method can effectively remove the noise of the EEG wave, and makes the characteristics of EEG more obvious.
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Computer Engineering. 2012, 38(01): 154-156. https://doi.org/10.3969/j.issn.1000-3428.2012.01.048Aiming at improving efficiency of D*Lite algorithm for path planning of robots, this paper presents three developed cost functions. The characteristics and the construction rules of the cost function are researched and a developed algorithm is proposed based on the Aε algorithm and the restriction of function admissibility. Experimental results show that the developed algorithm can improve the search efficiency and guaranteed the optimality of the result in a certain range.
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Computer Engineering. 2012, 38(01): 157-159,162. https://doi.org/10.3969/j.issn.1000-3428.2012.01.049To construct a uniform model for facial action of human-like Agent, the face is decomposed to six parts which are face, mouth, eyes, chin, tongue and head, according to physical anatomy in the paper. Then the method of multi-dimensional vector description is proposed through analyzing the movements of muscles on the face such as radiation muscles, orbicularis muscle and so on. The multi-dimension vector consists of a set of control parameters of facial action. The priority of the description can re-orientate a facial movement to another facial model. Experimental results show that the method can produce and descript the movement of human face realistically and easily.
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Computer Engineering. 2012, 38(01): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2012.01.050This paper proposes a method of expressing and analyzing behavior in moving vehicles based on video tracking and Finite State Automata(FSA). It gets foreground moving vehicles by using background subtraction method. In order to obtain accurate motion trail of vehicles, it predicts to achieve vehicle tracking based on Fast Normalized Cross-correlation(FNCC) theory. The state of vehicle behavior is transformed to that of continuous microscopic behavior by FSA. By combining time domain with spatial domain, it succeeds to analyze behavior of vehicles on the basis of motion tracking. Experimental results show that the method is able to gain status information of vehicles accurately.
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Computer Engineering. 2012, 38(01): 163-164,167. https://doi.org/10.3969/j.issn.1000-3428.2012.01.051In order to have a data reduction more effectively, this paper proposes a new manifold learning algorithm named Kernel Neighborhood Preserving Discriminant Embedding(KNPDE) which puts kernel mapping into the Neighborhood Preserving Discriminant Embedding(NPDE). The algorithm adopts the difference of between within-class similarity matrix and between-class scatter matrix as the discriminant criterion. So it can avoid receiving the restraint of full rank of within-class scatter matrix. The algorithm is applied to the face recognition and solves the problem of nonlinear and small sample for face data. The experiment results on the ORL and Yale face database show that this algorithm has a good recognition performance.
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Computer Engineering. 2012, 38(01): 165-167. https://doi.org/10.3969/j.issn.1000-3428.2012.01.052This paper proposes an iris feature extraction algorithm based on energy compensation and feature weighting to solve the problems that the capacities of the feature extraction with different sub-band of the Contourlet transformation are different. It uses orthogonal images to achieve energy compensation for the original images, estimates the weights of sub-bands by using General Gaussian Distribution(GGD), and gives larger weight for the feature with better classification capacity, so that the statistical information of the samples is made full use of and the features are extracted efficiently. Experimental results show that the algorithm has good robustness and improves iris recognition rate.
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Computer Engineering. 2012, 38(01): 168-170,173. https://doi.org/10.3969/j.issn.1000-3428.2012.01.053Traditional Ant Colony Algorithm(ACA) is applied to solve the query optimization problem of Data Warehouse(DW), it has some shortcomings such as premature convergence and slowly convergence. This paper improves the traditional ACA to address these issues. The pseudo-random proportion rule is introduced to the Max-Min Ant System(MMAS), and the Iterated Local Search(ILS) strategy is performed after each iteration. Experimental results show that the improved algorithm accelerates the convergence rate of the algorithm and improves the quality of the optimal solution in solving multi-join query optimization.
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Computer Engineering. 2012, 38(01): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2012.01.054The traditional sentence semantic similarity computing approaches usually only focus on one feature of a sentence and result in imbalance between the recall and the accuracy. Therefore, this paper describes a method for semantic similarity computation based on the Multi-feature of a Sentence(MFS). It is integrating more features of the weights of words, word semantics and sentence structure. The result of experiment show that compared with Jaccard coefficient method, the MFS method increased for comprehensive index F-measure. In a case-based question answering system the MRR value of the presented method is higher than other compared methods.
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Computer Engineering. 2012, 38(01): 174-176,179. https://doi.org/10.3969/j.issn.1000-3428.2012.01.055This paper proposes a financial distress pre-warning model based on Case-based Reasoning(CBR) and gray correlation degree. The method applies the gray relational analysis into CBR for business financial distress warning. The subjective and objective weights of characteristic properties are used to compute case similarity, which reflects the real similarity match. According to the important degree of each feature attribute to case retrieval, through the weight vectors remove interference for non-critical index to judge the case. Experimental results show that the sorting results of case similarity derived by the approach meet the actual situation and improve the retrieval efficiency of similar enterprises, it satisfies requirements of financial distress pre-warning.
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Computer Engineering. 2012, 38(01): 177-179. https://doi.org/10.3969/j.issn.1000-3428.2012.01.056Based on Kuhn’s evolutionary epistemology idea, this paper proposes a knowledge evolutionary algorithm based on paradigm shift. The paradigm is according to the solution, and an initial knowledge base is formed. The next work is to inherit excellent knowledge individuals by inheritance operator, produce novel knowledge individuals by innovation operator, eliminate the crisis of paradigm by update operator, and accordingly realize knowledge evolution. The optimal solution of issues can be gained from the optimal knowledge individual. Experiments are taken on optimization of functions. Compared with genetic algorithm, the proposed algorithm can search the global optimal solution with less population and faster speed.
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Computer Engineering. 2012, 38(01): 180-181. https://doi.org/10.3969/j.issn.1000-3428.2012.01.057The uniform table is designed by the good lattice point method may not be the best, because it cannot generate table of large factors, when n is even; meanwhile it generates only in the subspace of solution space. Based on the above issues, this paper introduces intelligent algorithm, including the Particle Swarm Optimization(PSO) algorithm and the Improved Simulated Annealing(ISA) algorithm. Comparison test results show that intelligent algorithm can generate uniform table of large factors according to the situation. Compared with the Good Lattice Point(GLP) method, both of the intelligent algorithms can achieve better uniformity table, and the deviation of uniform design table can be smaller constructed with ISA algorithm than PSO algorithm.
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Computer Engineering. 2012, 38(01): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2012.01.058Feature extraction in the multi-view environment is an important step in 3D reconstruction. However, it is a very time-consuming task. To accelerate the speed of extracting feature, this paper presents a parallel method to extract feature in the multi-view environment. The key views are selected by the texture feature discrepancy which is computed based on the grey level grows matrix. Harris corner detection algorithm and Blob detection algorithm are adopted to extract feature of the key view images. The method is parallelized by exploring the inherent parallelism of proposed procedures. Experimental results show that the method can select the key views efficiently, and the average speedup achieves 1.88 on a dual-core system.
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Computer Engineering. 2012, 38(01): 185-187,191. https://doi.org/10.3969/j.issn.1000-3428.2012.01.059Based on the application of natural language processing in the full cycle computer aided animation auto-generation technology, this paper design a system of information extraction in Chinese mobile phone text messages. The target is to extract animation information from mobile phone message. The system contains negative judgements and negative content recognition . Experimental results show that the recall ratio and precision of this system can meet the Information Extraction(IE) intensity requirements of the animation auto-generation system.
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Computer Engineering. 2012, 38(01): 188-191. https://doi.org/10.3969/j.issn.1000-3428.2012.01.060This article states the necessity of human-computer interaction on the basis of speech and proposes the implementation of speech control robot dog system. HTK and Julius are applied to build a large vocabulary continuous speech recognition platform. Besides, speech recognition technique is used to extract speech command to control the robot dog. A Finite State Machine(FSM) model is adopted to design the control system of the robot dog. Experimental results show this system does good in recognizing user’s speech command. The control system can complete the control tasks under different conditions effectively.
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Computer Engineering. 2012, 38(01): 192-194,207. https://doi.org/10.3969/j.issn.1000-3428.2012.01.061This paper studies the path sorting and integration problem in automatic path planning system of painting robots. To take both path length and painting direction into account, the problem is modeled as an open Generalized Traveling Salesman Problem(GTSP), and the corresponding optimization objective and cost matrix are created. An Ant Colony Optimization(ACO) algorithm is proposed to solve the problem, and the searching ability as well as convergence performance in the global solution space is guaranteed with the parallelism and positive feedback of ACO. Simulation experimental results show the validity of the method.
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Computer Engineering. 2012, 38(01): 195-196,210. https://doi.org/10.3969/j.issn.1000-3428.2012.01.062Text categorization method based on centroid shows poor performance. This paper proposes a centroid vector construction method based on feature selection named FSCC. By computing feature selection value between features and categories, the centroid vector are calculateed by the formula of centroid feature weight. Finally, a non-normalized cosine similarity measure is employed to calculate the similarity score between a text vector and a centroid. Experimental result show that FSCC significantly outperforms traditional centroid-based methods and state-of-the-art Support Vector Machine(SVM).
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Computer Engineering. 2012, 38(01): 197-198,214. https://doi.org/10.3969/j.issn.1000-3428.2012.01.063Some complex networks in real world are not consenting the preference linking of Scale-Free(SF) network, but nodes has self-similarity. This paper proposes the network evolution model constituting based on self-similarity and researched the properties. To prove the network has the self-similarity formed with nodes self-similarity, it uses the volume dimension as the criterion reveal complex network self-similarity. Both theoretical analyses and simulation results show that the model can describe evolution and characters more exactly for many complex networks of the real world.
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Computer Engineering. 2012, 38(01): 199-200. https://doi.org/10.3969/j.issn.1000-3428.2012.01.064The principles of traditional head detection methods are mostly based on the detection of the face and the hairs, these methods have error. Aiming at this problem, this paper presents a head detection method based on Randomized Hough Transform(RHT) focusing on the feature that the contour of human’s head is similar as a circle. Object’s contour is obtained by edge detection based on canny operator. The circles are detected by the method of RHT in every independent curve, and the heads are marked. Experimental results demonstrate that this method has higher accuracy, lower time cost and greater scope of application in contrast with the existing methods of head detection.
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Computer Engineering. 2012, 38(01): 201-203. https://doi.org/10.3969/j.issn.1000-3428.2012.01.065A digital literature image denoising algorithm based on biological visual mechanism is proposed. Simulating the receptive field response characteristics of simple cells in primary visual cortex, the basis functions of digital literature image are obtained by image feature extraction. The neuron response of noisy images is calculated according to the sparsity of animals’ vision perception system. Sparse coding shrinkage is used to shrinkage the response coefficient, and the neurons that respond stronger are used to reconstruct the image. Compared with the traditional methods of image denoising, the experimental results demonstrate that this method can reduce Gaussian noise more effectively, and has a better effect in preserving image detail information.
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Computer Engineering. 2012, 38(01): 204-207. https://doi.org/10.3969/j.issn.1000-3428.2012.01.066In Content Based Image Retrieval(CBIR) system, the conventional color histogram and spectral histogram can not meet the continuity and similarity of color transition and changes in gradient orientation and magnitude. A image retrieval algorithm of the nonlinearly fuzzy chromatic histogram and the nonlinearly fuzzy gradient-vector histogram is presented. It can depict images with a form which can answer for the human nonlinearly cognitional nature in visual field well. Based on other existing features in spectrum and statistics, the features group combinatorics of selection method is constructed, it selects the most proper image features group combinatorics to promote the effectiveness of image retrieval system. Experimental result shows that, compared with other retrieval algorithms, the proposed algorithm has well retrieval quality.
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Computer Engineering. 2012, 38(01): 208-210. https://doi.org/10.3969/j.issn.1000-3428.2012.01.067Current solution only calibrates coordinates the points to reduce the CPU resource occupation. It loses large amount of control surface information and limits the development of more complex interactions. As to increase the speed of image processing, by exploiting the advantages in computing area of modern programmable Graphics Processing Unit(GPU), this paper presents a solution to transport the image calibration and image processing into GPU. In order to support more complex manipulation and interaction, the process of image calibration and processing is improved. With higher process speed and less CPU resource, the whole image is calibrated to keep all the information of control surface. The analysis and experiments prove its good practicability and effectiveness.
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Computer Engineering. 2012, 38(01): 211-214. https://doi.org/10.3969/j.issn.1000-3428.2012.01.211To improve the quality of the image, this paper presents an improved image denoising method based on high density discrete wavelet transform. The two-dimensional fast decomposition and reconstruction algorithm is given, and it is used to decompose the image in multi-scale. The wavelet coefficients at each level are processed with bivariate shrinkage threshold according to the correlation of wavelet coefficients of adjacent scales. The denosed image is reconstructed. Experiments show that compared with other wavelet denoising method, the method proposed in the paper further enhances the image denoising performance, and still keeps the details of the image.
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Computer Engineering. 2012, 38(01): 215-216,219. https://doi.org/10.3969/j.issn.1000-3428.2012.01.069According to the degraded effect of images obtained in foggy weather, a new enhancement algorithm based on dark channel prior and local interpolating histogram matching is proposed. The sky region is separated from the degraded image using dark channel prior. The local interpolating histogram matching algorithm is adopted to deal with the non-sky region of the image. The disposals of after and before images are fused by principal component analysis. Experimental results show that the algorithm can not only efficiently avoid interfere with sky regions, but also enhance the contrast of degraded images and obtain satisfying visual effects.
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Computer Engineering. 2012, 38(01): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2012.01.070The similar statistical properties between pixels in lossy compression and resampling operation makes the lossy compression image hard to detection. In order to solve the problem, this paper presents a resampling detection algorithm which is applied to lossless compression. It investigates the spectrum characteristics of an image by analyzing the periodicity of interpolating signal and then estimate interpolation coefficient of the image resampling. Experimental results indicate that this algorithm has strong robustness and wide application, and it has precision rate for JPEG lossy compression image resampling detection.
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Computer Engineering. 2012, 38(01): 220-221,224. https://doi.org/10.3969/j.issn.1000-3428.2012.01.071A fast registration algorithm based on points is presented. Features from Accelerated Segment Test(FAST) is adopted to extract feature points. Contrast Context Histogram(CCH) is exploited to describe feature points. Best Bin First(BBF) searching algorithm is used to accelerate matching. To improve the robustness of the algorithm, Random Sample Consensus(RANSAC) is utilized to remove the mismatched points. Experimental results show that, compared with other registration algorithm such as SIFT and SURF, the proposed algorithm increases the speed observably while keeping the stability of the algorithm.
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Computer Engineering. 2012, 38(01): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2012.01.072Traditional image restoration algorithms always deal with Gaussian noise, however, the real astronomical images are polluted by Gaussian and Poisson mixed noise. Therefore, this paper introduces a imaging model of Poisson-Gaussian distribution, makes an effective approximation to the Maximum Likelihood(ML) algorithm based on the mixed model, and proposes a modified ML algorithm based on Poisson-Gaussian mixed noise to avoid the sensitivity to noise and the dependence to the original estimation of PSF. Experimental results show that this algorithm works well, and the robustness is well.
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Computer Engineering. 2012, 38(01): 225-226,235. https://doi.org/10.3969/j.issn.1000-3428.2012.01.073Traditional image segmentation based on grey relational analysis makes many mistakes. For this problem, this paper gives a complex optimization method based on grey relational analysis and Radial Basis Function(RBF) neural network. It optimizes RBF neural network by Quantum Genetic Algorithm(QGA). In this way, the approach performance of RBF neural network is improved. It extracts the edge information by grey relational analysis, identifies which pixel is noise, and gives this information to the optimized RBF neural network. Its good approach performance can rectify the mistake mentioned above. Experimental results show that the outcome of image segmentation procedure is better, and eliminates the noise more exactly.
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Computer Engineering. 2012, 38(01): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2012.01.074A new formation technique that varies signs and locations is put forward, which is based on different structure of orthonormal four-band wavelet as well as optimizing filter bands. Different cases are designed under the same constrained conditions, the sparseness of wavelet coefficient after image decomposition once is compared, and parallel tests of image compression are done according to SPIHT algorithm. Results indicate that the new structure methods of wavelet filter perform better than the others of those cases and enjoy an obvious advantage in compression.
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Computer Engineering. 2012, 38(01): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2012.01.075Artificial Bee Colony(ABC) algorithm has some drawbacks such as getting in local minima, searching accuracy is not high and convergence rate is slow. This paper presents a Chaos Bee Colony(CBC) algorithm with a new formula to replace the standard food source position updating formula of ABC, and chaotic search mechanism is introduced to the bee swarm local search. Performance analysis shows that CBC algorithm has faster convergence rate, more global search capability. The algorithm is introduced into the construction of gas outburst prediction model, experimental results prove the validity of the model.
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Computer Engineering. 2012, 38(01): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2012.01.076The traditional Radix-4 Booth encoding will produce the complement computing operation emerged in the process of negative partial product generation, which influences the word efficiency for multiplier. Aiming at this problem, this paper puts forward a multiplier optimal design of recombining partial products. By adding an “or” gate operation and simple hard-wired recombinant, it avoids addition operation in the complement computing process, and does not generate redundant partial product. The validated result on 32-bit multiplier shows that the design can effectively reduce the critical path delay and chip area consumption.
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Computer Engineering. 2012, 38(01): 236-238,241. https://doi.org/10.3969/j.issn.1000-3428.2012.01.077To solve the problems of trucks monitor and statistics are not accurate when using Global Positioning System(GPS) technology in open pit, a new algorithm of locations drift identify and correction is proposed. By utilizing the idea of pheromone designs the dynamic path generation algorithm, the algorithm can update the path maps automatically, and the trucks can runs on a relative standard path, which solves the problem of location drift and improves the precision of statistics. The validity of the algorithm is proved by practical application and data analysis in system.
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Computer Engineering. 2012, 38(01): 239-241. https://doi.org/10.3969/j.issn.1000-3428.2012.01.078In this paper, a high throughput fully programmable Reed-Solomon(RS) decoder on a multi-core processor is presented. By fully extracting the parallelizable operations of the RS decoder, it proposes multiple optimization techniques to improve system throughput including: task-level parallelism on many cores, data-level parallelism on each SIMD core, minimization of memory access, and route-length-minimized task mapping techniques. For RS(255, 239, 8), it can achieve a throughput of 4.35 Gb/s at the worst case of the incoming codeword.
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Computer Engineering. 2012, 38(01): 242-244. https://doi.org/10.3969/j.issn.1000-3428.2012.01.079A high speed transmission platform based on Ethernet is introduced. The platform utilizes Field Programmable Gate Array(FPGA) as central control unit which is in charge of timing control of Ethernet interface chip and implementation of simple Transmission Control Protocol/ Internet Protocol(TCP/IP). The platform has abundant interface which makes it easily be used as middleware of experiment equipment and PC. It has high throughput which nearly reaches the full performance of 100 Mb/s Ethernet.
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Computer Engineering. 2012, 38(01): 245-247. https://doi.org/10.3969/j.issn.1000-3428.2012.01.080This paper investigates the problem of H∞ output tracking for stochastic network-based control system. Attention is focused on the design of controller, which guarantees the stability of systems and a prespecified H∞ performance for the stochastic network-based control systems with respect to all energy-bounded input signals. Sufficient conditions are proposed in terms of linear matrix inequality, and the corresponding controller design is cast into a convex optimization problem. A numerical example illustrates the effectiveness of the proposed H∞ output tracking design scheme.
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Computer Engineering. 2012, 38(01): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2012.01.081In order to generate a variety of innovative 3D animation modelings automatically, an improved Cellular Genetic Algorithm(CGA) is proposed. ACIS rule expressions are used to unevenly scale the existing 3D animation modeling in three directions, and tree-structure coding is adopted for the generation of rule expressions with diverse length and content. Through human-computer interaction, expert knowledge is used to determine the fitness value of individuals. Experimental results on ECTDS of 3D animation modeling innovation system show that the algorithm can generate a series of vivid and creative modelings.
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Computer Engineering. 2012, 38(01): 251-252,255. https://doi.org/10.3969/j.issn.1000-3428.2012.01.082In the augmented reality system based on ARToolKit, the virtual objects are registered on the different marks collide because of interaction which causes unreal mix situation. To solve this problem, this paper proposes an algorithm which can adjust the location and pose of virtual objects according to detected information about collisions, and make mix situation of virtual and actual reality remain realistic. User can obtain more interactive experience from the system. Experimental result shows that this method can get a nature and true interactive experience.
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Computer Engineering. 2012, 38(01): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2012.01.083In the paper, stock market and real estate system are regarded as a class of complex adaptive system. In order to researching the modeling of the class of system, the Complex Adaptive System(CAS) theory is applied into the paper. The modeling approach based on Multi-Agent is adopted in the paper, it designs the stochastic decision Agent, simulation Agent, BP neural network Agent. It introduces the order book technology to realize the communication between Agents. The dynamic evolution under uncertain environment of the class of system is simulated, and the validity of the model is confirmed.
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Computer Engineering. 2012, 38(01): 256-257,260. https://doi.org/10.3969/j.issn.1000-3428.2012.01.084This paper presents a membership management scheme based on grouping in P2P network. It divides the peers into groups. Every group includes the group heads and the members. It develops an ID-based key generation scheme. It uses the symmetric polynomial to establish the key pairs for the members that reduce the interactive of the peers and enhance security. The group heads update the key periodically, it can detect the malice peers. Experimental result shows that this scheme is of high efficiency and little communication.
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Computer Engineering. 2012, 38(01): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2012.01.085When LT codes are transmitted in the Binary Input Additive White Gaussian Noise(BIAWGN) channel, traditional Gaussian approximation method, which is used to predict the bit error rate performance of Belief Propagation(BP) decoding algorithm, is not accurate. So this paper proposes an improved Gaussian approximation method to predict bit error rate performance. The degree distribution of input node is Poisson distribution and the corresponding soft information is a Gaussian mixture. Based on this method, a new method used in the design of good degree distribution for LT codes is given. Simulation results show that the improved method is more accurate than the previous one.
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Computer Engineering. 2012, 38(01): 261-263,267. https://doi.org/10.3969/j.issn.1000-3428.2012.01.086Demand uncertainty brings great trouble to retailers ordering decisions. Based on mainstream development technologies and combination of newsboy model and greedy algorithm, an ordering management system for retailers is developed to support their ordering decisions. Simulation results show the ordering scheme provided by the system has great advantages. All models and technologies developed in this paper can be widely used and have an alluring prospect.
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Computer Engineering. 2012, 38(01): 264-267. https://doi.org/10.3969/j.issn.1000-3428.2012.01.087Aiming at the low efficiency of searching back-end data base and the poor mobility of reader in the existing Radio Frequency Identification(RFID) protocols, this paper proposes a new RFID protocol with ElGamal re-encryption algorithm, and uses GNY logic to prove security analysis of the new protocol by using the GNY logic shows that it is secure against the attacks such as retransmission, desynchronization, and impersonation, and it can resist the privacy attack on the tag. As both the number of searching back-end data base and the computational quantities of Hash algorithm in the new protocol are reduced, the new protocol is of high efficiency.
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Computer Engineering. 2012, 38(01): 268-269,272. https://doi.org/10.3969/j.issn.1000-3428.2012.01.088This paper designs an instruction Cache based on Predict Buffer(PB) mechanism to reduce the energy consumption of on-chip Cache of the processor. It can make instruction needed by processor hit in buffer mostly by PB control component predict, thus power dissipation of instruction Cache can be avoided. Simulation result of seven benchmarks shows that PB mechanism can save more than 23.23% power and improve performance by 7.53%.
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Computer Engineering. 2012, 38(01): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2012.01.089It will affect the “depth” effect when using 2D video filtering method to process 3D video. To address the problem, by counting the blocks of video effects and deep loss rate, and combining the subjective grading, it assesses the video quality. Based on assessment results and according to the depth of information, it improves traditional 3D video post-processing method. Experimental results prove that the improved method can create more realistic 3D experiences to the audience.
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Computer Engineering. 2012, 38(01): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2012.01.090This paper proposes an adaptive quantization algorithm named AQSC in transform-domain Distributed Video Coding(DVC). Only the important Discrete Cosine Transform(DCT) bands determined by the statistical characteristics of DCT coefficients are quantized and coded, while the less important ones are not quantized and coded, but replaced directly by the side information in the decoder side. Experimental results show that AQSC achieves rate-distortion improvements and reduces the decoding rates, compared to IST-TDWZ scheme.
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Computer Engineering. 2012, 38(01): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2012.01.091In emergency indoor occasion, aiming at the following locating system, this paper proposes a calibration-free indoor location method based on directional signal compensation. This paper uses two directional antenna to send signal, collects several feature point as the training data, extracts signal feature and median filter as a signal compensation. It establishes the localization model by joining not calibration data. The model is applied to the users' positions location. Experimental result shows it can reach high accuracy in the condition of less access points and label data.
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Computer Engineering. 2012, 38(01): 279-280. https://doi.org/10.3969/j.issn.1000-3428.2012.01.092In order to solve the problem of small size sampling inspection for pass-fail products, combining the single sampling inspection and Sequential Posterior Odd Test(SPOT) method, a new sampling inspection method for pass-fail data distribution is proposed, which not only can reduce the sample size due to making effectively use of the prior information, but also can very easily make sampling inspection project. A special sampling inspection case is presented, simulation result shows that the proposed method is suitable for sampling inspection under the condition of small size sample.
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Computer Engineering. 2012, 38(01): 281-283,287. https://doi.org/10.3969/j.issn.1000-3428.2012.01.093Considering the Phased Mission System with Common Cause Failures(PMS_CCF), the dependencies across phases and common causes make the reliability analysis more complex. A method based on Monto Carlo method is presented. The method makes use of explicit failure tree to obtain explicit common cause structure function, utilizes the idea of statistical sampling to deal with the dependencies. Then reliability result are calculated. A example is probed into showing the simulation feasibility. Based on the contrastcion between the simulate result and the analytic result, the two results fally well. The simulation is feasible.
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Computer Engineering. 2012, 38(01): 284-287. https://doi.org/10.3969/j.issn.1000-3428.2012.01.094In order to satisfy the demands of full-system, full-function, full-scope and full-factor for large scale equipment tests, according to the standard of Data Distribution Service(DDS) system, this paper proposes a new architecture of large scale equipment virtual test system by using Test and Training Enabled Architecture(TENA) as the main design idea. Taking the large-scale warship equipment virtual test system as example, the main function of each module in the system is analyzed and an example of system interior DDS middleware is designed. Application result shows that the architecture is suitable for the development of virtual test environment for various platforms, systems and equipments.
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Computer Engineering. 2012, 38(01): 291-292,封三. https://doi.org/10.3969/j.issn.1000-3428.2012.01.096Based on the Geographic Information System(GIS) and Expert System(ES) combined structure system, constructs highway ecological landscape evaluation system. The system uses a modular design technology, which includes the man-machine interface, integrated database, spatial database, knowledge base, inference engine, knowledge acquisition and interpretation of program modules. Using intelligent control interface and the application of heuristic reasoning, strengthen and improve the GIS system function, the use of expert knowledge and provide scientific decision and consultation. Implementation results verify the efficiency of the system.
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