05 May 2010, Volume 36 Issue 9
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Computer Engineering. 2010, 36(9): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2010.09.001The recommended tracking spacing for an archimedes spiral ground target search of Unmanned Aerial Vehicle(UAV) is studied. To find a recommended track spacing, three models are build according to fact. It analyzes the strengths and weaknesses of each model, describes which condition each model adapted. This analysis combines three analytical functions into a single parameterized expression. To find the best-fit parameters maximizing probability of detection, a simulation experiment with a nearly orthogonal latin hypercube design is used. The model can present a method for solving the optimal setting track spacing for a spiral ground target search of UAV. The research provides a theoretical reference for setting up spiral search strategy.
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Computer Engineering. 2010, 36(9): 4-6,13. https://doi.org/10.3969/j.issn.1000-3428.2010.09.002Aiming at the needs of the geographic information data change, this paper presents a solution of Geographic Information System(GIS) based on geographic information data change detection. It discusses the design idea, functions and system framework, uses the techniques of ArcObjects, ArcSDE and Oracle to implement, and detects the change information between the geographic information data of different times. Application results show that the high accuracy of the geographic data change information is validated.
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Computer Engineering. 2010, 36(9): 7-9,13. https://doi.org/10.3969/j.issn.1000-3428.2010.09.003In order to meet the requirement of performance price ratio optimization for Time Division-Synchronous Code Division Multiple Access(TD-SCDMA) wireless network, aiming at this shortage, this paper designs hierarchical optimization model for network planning. This model can solve the problem of the relation between coverage and capacity. In order to solve the model, it proposes a hierarchical multi-objective optimization algorithm. This algorithm can decide optimal level of object function on the basis of practical planning area, stratify object and requirement of TD-SCDMA network planning, and realize the best base station location selection under given condition.
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Computer Engineering. 2010, 36(9): 10-13. https://doi.org/10.3969/j.issn.1000-3428.2010.09.004A real-time simulation and detection system for control system of space optics remote sensing device is designed based on precise timing and multitask proportion method in Windows OS. Through external PCI device controlled by FPGA touching the computer external interrupt periodically, precise timing is realized. For work tasks order of transmitting, parse and saving is arranged newly by rule of PRI from high to low. Experimental results show that timing accuracy achieves 0.1 ms. All tasks can be executed punctually, parsed immediately and saved accurately, requirements of real-time simulation and detection are satisfied.
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Computer Engineering. 2010, 36(9): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2010.09.005Aiming at the grayness issue of evaluation metrics for performance evaluation of routing protocols in Delay and Disruption Tolerant Networks(DTN), this paper proposes a comprehensive evaluation model for routing protocols in DTN. It uses Analytic Hierarchy Process(AHP) to determine the weighting coefficients of evaluation indexes, applies the method of grey theory to construct the evaluation sample matrix and grey ranking to gain the coefficients of the grey evaluation and the weighting matrix. Based on the model, the subjective factors that influence the performance evaluation are restricted greatly and the objectivity of performance evaluation results is improved. Experimental results show that the model is effective.
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Computer Engineering. 2010, 36(9): 17-19,2. https://doi.org/10.3969/j.issn.1000-3428.2010.09.006By designing a structure of run-length associated indirectly with object to solve the problem of run-length labeling conflict in real time, an efficient run-length based and raster-scanned region labeling algorithm is proposed, which can acquire the run-length region representation by only one scan. The algorithm owns low complexity for easy implementation, and can be easily extended to implement parallel labeling in parallel computing system. Experimental results show that the algorithm is more efficient than other algorithms in serial labeling, and gains approximate linear speedup ratio in parallel labeling.
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Computer Engineering. 2010, 36(9): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2010.09.007This paper proposes an asynchronous Advanced Encryption Standard(AES) S-box circuit with the performance of anti-Differential Power Analysis(DPA) attacks. In this S-box, composite-field arithmetic is used to attain the compact S-box architecture, the single-rail asynchronous pipelines are inserted in the data-path circuits to reduce the S-box circuit’s power, its property of anti-DPA attack is improved by introducing the locally inserting asynchronous dual-rail circuits and the disordered-data mechanism. Simulating validation and test are done by the presented simulating DPA attack platforms for the S-box.
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Computer Engineering. 2010, 36(9): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2010.09.008In order to provide support for multiple service registry center, and convenient for recording and mining of service access log, this paper proposes a distributed service executive mining framework based on P2P. Aiming at the requirement of cross-organizational associated business, it constructs service registration union mechanism using this framework. In registration union, it designs Web service associated rule mining algorithm based on log base to progress frequency sequence mining of composite service. Simulation results show that this algorithm can mine executive and interactive information effectively, enhance efficiency of service selection and service composition.
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Computer Engineering. 2010, 36(9): 26-28,3. https://doi.org/10.3969/j.issn.1000-3428.2010.09.009Aiming at the function test problem of Web application, this paper proposes a Web application modeling and test method based on use case and sequence diagram. It extends use case diagram hierarchically into Use Case Transition Model (UCTM) by Unified Modeling Language (UML). Each use case of UCTM is described by sequence diagram, which can be converted automatically into a Restricted Directed Graph(RDG). In order to control status space explosion, it proposes a piece of Constraint Message Coverage criterion(CMC), test case generated from RDG can satisfy CMC, and CMC can control the number of test case.
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Computer Engineering. 2010, 36(9): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2010.09.010Based on the historical data, what-if analysis can analyze the hypothetical scenarios and provide useful information for the decision-maker. Aiming at the problem of re-computation of data cubes in what-if analysis, this paper presents an algorithm of incremental computation of data cube for Max function to reduce the access time of fact table. Experimental results show that the performance of incremental computation can be improved about 15%.
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Computer Engineering. 2010, 36(9): 32-34,4. https://doi.org/10.3969/j.issn.1000-3428.2010.09.011In order to utility the computing ability of many high-performance resources, this paper designs a scalable computing acceleration middleware for desktop Problem Solving Environment(PSE). It is composed of application layer, middle layer and computing layer, so that the design complexity is decreased. It supports a variety of parallel back-ends and distribution extension and plug and play of parallel back-ends. Experiment on LU factorization of Matlab with the acceleration middleware proves the validity of the middleware.
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Computer Engineering. 2010, 36(9): 35-37,4. https://doi.org/10.3969/j.issn.1000-3428.2010.09.012Aiming at the sequential codes containing a large number of loops, a new method for parallelism based on Thread-Level Speculation (TLS) by loop selection is proposed. After optimal selection of loops, a loop set is built for parallel operation. The codes of loops which are included in the loop set are selected for parallel operation because of high parallelizing efficiency to improve the speed of serial program operation. Compared with simple inner or outer loop parallelization, simulation results demonstrate the average speedup of 9 benchmark applications raise 23.8%. Therefore, higher parallelizing efficiency can be achieved.
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Computer Engineering. 2010, 36(9): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2010.09.013This paper proposes an algorithm for classification of data stream based on multiple class-association rules——SCMAR. It changes the construct process of FP-tree to improve its time and space efficiency, computes and maintains all the frequent rules by using Hoeffding bound and dynamically updates them with the incoming data stream. It stores the rules with CR-tree, and stores the statistic information for each rule, so when classing the data, it can select appropriate rule to construct classifier. Theory analysis and experimental results show that SCMAR algorithm is efficient and effective.
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Computer Engineering. 2010, 36(9): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2010.09.014To overcome the starvation phenomena caused by the existing algorithm for the response time of a lot of tasks is longer in the Intelligent Network Disk(IND) system, an improved algorithm is presented. In the algorithm, factors of tasks are computed by the execution time and weight of step chains, and the range of factors and the limit of executed time of tasks are set. Experimental results demonstrate that it solves the starvation phenomena at a certain extent and makes the weighted total completion time approximately best.
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Computer Engineering. 2010, 36(9): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2010.09.015Aiming at the problem that allocating disk space result of the distribution of user files stored is concerned by the people, this paper presents a policy which is named dynamic allocation of disk space in distributed storage system. It maintains the size of the user disk quota unchanged, and allocates the actual storage space for user on demand according to the amount of data difference in each storage node. Compared with traditional disk allocation mechanism, this method is more simple and flexible, and it can rather adapt to the dynamic changes of the network storage data, and improve effectively the utilization of disk space resources.
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Computer Engineering. 2010, 36(9): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2010.09.016The task-oriented cooperative programming based on Ontology and multi-Agent is put forward aiming at the drawback of the Object-Oriented Programming(OOP) and Aspect-Oriented Programming(AOP). This paper introduces the decomposition principle and descriptive method of task, and nine programming steps. An example which shows how to apply the method is given. It improves the modularity of crosscutting concerns in software, so that software is easily realizable, readable, evolutionary and reusable.
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Computer Engineering. 2010, 36(9): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2010.09.017This paper proposes a new twig pattern index algorithm and a non-retracement tagging filtering method. It enhances filtering computing speed of twig pattern subscribe by increasing a few storage resources of the system. A tag is set for each predicate in the query to simplify matching operation, and through AND operation to filter the queries without retracement. Experimental results show that the algorithm has good performance and adapts to the system with millions of subscriptions.
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Computer Engineering. 2010, 36(9): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2010.09.018Aiming at the problem of boundary effects in Adaptive Random Testing(ART), based on the basic thought of Mirror ART(MART), this paper proposes a new algorithm named MART by introducing mirror distance. Testing cases generated by the algorithm are more evenly spread in the input domain by changing the distance judgment strategy between the candidate testing cases and the successful testing cases. Simulation experimental result verifies that MART algorithm can solve the problem of boundary effects, and its efficiency of finding failure is higher than that of DART algorithm and MART algorithm.
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Computer Engineering. 2010, 36(9): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2010.09.019In evolutionary test, design of fitness function is a crucial work. Traditional work can not design a fitness function with favorable guidance to all node-node-oriented tests. A system model of evolutionary test with node-node-oriented method is presented, and an improved method of fitness function is designed. The method doesn’t consider the execute order of nodes and control flow, but is based on the independence of nodes. Experimental result indicates that this new method can generate test data with less cost and more steady performance for cover criterion which has no data dependence in discrete nodes.
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Computer Engineering. 2010, 36(9): 59-61,6. https://doi.org/10.3969/j.issn.1000-3428.2010.09.020This paper introduces the existing meteorological software design pattern. It analyzes the features and functional requirements of domestic meteorological business, and gives a new design pattern. The data conversion and quality control model, component packaging model, professional module plug-in model and the general framework model under this pattern are discussed. The design patterns in the data storage, component development, interface design, respond to technology sharing, operational changes and technological upgrading of the treatment are explained. The purpose of the pattern is to solve reuse problems of system resources and technology from low layer to high-level, and realize resources sharing and intensification system design.
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Computer Engineering. 2010, 36(9): 62-64. https://doi.org/10.3969/j.issn.1000-3428.2010.09.021Connections between bipartite graph’s bicliques and conceptual clustering are analysed. On the basis, according to the features of data streams, a new conceptual clustering algorithm is proposed to cluster data streams whose attributes are boolean. The data streams are partitioned into a set of segments, and with the arrival of each segment, a local set of approximate maximum ε-bicliques is generated, then the algorithm updates the global set effectively to cluster the entire data streams. Experimental results show that the algorithm has good time efficiency and space efficiency.
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Computer Engineering. 2010, 36(9): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2010.09.022In clustering of high dimensional data, most of the existing algorithms can not reach people’s expectation due to the curse of dimensionality. Based on the classic PreDeCon algorithm, this paper presents the StaDeCon, a density clustering algorithm for high dimensional data, which introduces a measure of subspace dimensional weighting to avoid the problem existing in PreDeCon caused by using full dimensional distance, and in this way, the quality of clustering is improved. Experimental results both on artificial and practical data show that the algorithm is more accurate, and it is effective and feasible.
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Computer Engineering. 2010, 36(9): 68-69,7. https://doi.org/10.3969/j.issn.1000-3428.2010.09.023Aiming at the problem that the resource consumption of symbolic execution is too large, this paper proposes an intra-procedural analysis method which is named modeling execution path as process, and combines using the method of modeling objects which is named lazy initialization. A tool prototype which can detect the vulnerability of C code is implemented, and analyzes the Intermediate Rresent(IR) of Phoenix as the direct object. Some known vulnerabilities of Openssl and Apache are verified, and a DOS vulnerability of the version 1.11.4 of wget is detected.
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Computer Engineering. 2010, 36(9): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2010.09.024With the application of software re-engineering, the data representation, input control and data handle which are separated by MVC pattern, make the structure of data middleware clearer and enhance the reuse of various parts. The loose coupling of model, view and control promote the favorable stability, flexible and expansible in data middleware. By re-engineering process of a legacy system middleware, the model is proved to be practicable and effective.
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Computer Engineering. 2010, 36(9): 73-76,7. https://doi.org/10.3969/j.issn.1000-3428.2010.09.025Aiming at the shortage of low parallelism degree and load imbalance in existing partition algorithm, this paper presents an automatic partition algorithm based on multi-region and multi-code problem. This algorithm uses loop distribution algorithm to realize processor distribution between computational domain, uses recursion dichotomy based on Block for splitting undirected graph to realize task distribution in computational domain. Experimental results show that this algorithm can make allocated number of processor equation all of the computational space, and the communication traffic between processors is least.
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Computer Engineering. 2010, 36(9): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2010.09.026Focused on the close relative between temporal queries and time attribute, this paper uses temporal interval as an index key of the modified B+-tree to create indexes. The modified B+-tree is denoted Changing B+-tree(CB+-tree). Through the experiments, new index method processes several typical queries in temporal XML better than querying in B+-tree index and DOM method.
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Computer Engineering. 2010, 36(9): 80-81,8. https://doi.org/10.3969/j.issn.1000-3428.2010.09.027Similarity propagation is very important for calculating similarity in ontology concept, the existing algorithms of similarity propagation usually use a fixed proportion of spreading value, these algorithms do not take reasonable quantitative analysis for spreading value. Aiming at the above problem, this paper proposes an improved algorithm of similarity propagation, which is based on information content of concept, the algorithm adopts the value of information content of matched node to determine matching probability of the matched node’s children and parents, and more accurate propagating value is obtained by adjusting spreading value according to the matching probability. Theoretical analysis and experiment results show that the algorithm is efficient.
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Computer Engineering. 2010, 36(9): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2010.09.028In order to solve the problem of ontology heterogeneity in semantic Web, a multi-strategy ontology mapping algorithm based on conceptual similarity computing is proposed. The candidate set and information gain are brought to simplify the calculation process. Calculating of conceptual similarity is based on name, conceptual attribute, conceptual relation, instance similarity and structure similarity. Correct and complete mappings are finally obtained through combination of all these similarities. Experimental result shows that the algorithm is more effective.
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Computer Engineering. 2010, 36(9): 85-86,8. https://doi.org/10.3969/j.issn.1000-3428.2010.09.029During the development of software, the shared memory always meets potential problem, one process may consume too much memory so that other procsses may be starved. Aiming at the problem, this paper describes an implementation of dynamic memory management based on Linux kernel to limit the maximum memory size of each process that can be applied, avoids system crash caused by memory leak as well. Experimental results show that the management has a high effectiveness and is easy to be used.
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Computer Engineering. 2010, 36(9): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2010.09.030In order to solve the problem of computing core error of inconsistent decision table, a definition of converting inconsistent decision table into consistent decision table is put forward. In the definition, the discernibility matrix is redefined, and a method of computing the core is presented. It is proved that the core acquired from the method is the core based on positive region, a new algorithm of computing core, which is suitable for consistent and inconsistent decision tables, is designed. Instance shows that the algorithm is correct.
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Computer Engineering. 2010, 36(9): 90-93. https://doi.org/10.3969/j.issn.1000-3428.2010.09.031According to the problem of inefficient data distribution due to the difference of program popularity in current Peer-to-Peer(P2P) Video-on-Demand(VoD) systems, this paper proposes a P2P VoD streaming system with partitioned buffer-scheduling strategy. The strategy divides user buffer into two partitions, in which one considers the local need of the peer itself and the other considers the global need of the whole network to make scheduling, so as to optimize the distribution of program data between user nodes and provide better playing quality for users. Simulation indicates that such system design and strategy are effective.
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Computer Engineering. 2010, 36(9): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2010.09.032Based on the linear network coding, this paper proposes the maximum decodable linear network coding. It proves that whether there exists a maximum decodable linear network code for a given network is NP-hard, and gives an approximate polynomial algorithm with a heuristic rule to construct such a network code. Simulation proves that the maximum decodable linear network coding helps to gain better network capacity.
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Computer Engineering. 2010, 36(9): 97-99,1. https://doi.org/10.3969/j.issn.1000-3428.2010.09.033This paper investigates the non-ideal analog front-end effects in Orthogonal Frequency Division Multiplexing(OFDM) based Ultra-wide Band(UWB) system and proposes a joint estimation algorithm for Multi-Band OFDM(MB-OFDM) based UWB system. The proposed algorithm can deal with Carrier Frequency Offset(CFO) and Sampling Frequency Offset(SFO) estimation with the presence of frequency dependent In-phase and Quadrature-phased(I/Q) imbalance. Then frequency dependent I/Q imbalance and channel response are jointly estimated. Simulation results show that the proposed joint estimation and compensation algorithm is competent in practical MB-OFDM based UWB system.
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Computer Engineering. 2010, 36(9): 100-102. https://doi.org/10.3969/j.issn.1000-3428.2010.09.034Aiming at broadcast-storage grid, this paper indexes the programs based on Uniform Content Location(UCL), and transmits the Broadcasting IP(BIP) packets comprised of IP packets which is contained of UCL information. It presents a hardware filtering system based on UCL for BIP packet. The transmission process of broadcasting network is simulated, and the BIP packets are formed through UCL indexing in source side. In Ethernet terminal, the BIP packets are resolved and filtered in the data link layer by Field Programmable Gate Array(FPGA). The results are delivered to user to store. Experimental results demonstrate the effectiveness of this system.
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Computer Engineering. 2010, 36(9): 103-105,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.035Aiming at the failed single point problem for Home Agents(HAs) in mobile multicast, an implementation mechanism of Multiple Home Agents for Mobile Multicast(MHAsMoM) is proposed. The problem of home registration among multiple HAs is solved. Meanwhile, a novel application-layer anycast algorithm is adopted in the scheme, which can choose the “nearest” HA from multiple HAs in the home network for mobile multicast receivers. Analysis results show MHAsMoM can not only solve the problem due to HA as a central point of failure, but also provide better anycast resolution service.
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Computer Engineering. 2010, 36(9): 106-108. https://doi.org/10.3969/j.issn.1000-3428.2010.09.036In order to improve the real-time operability and efficiency of network performance management and fault management, this paper studies the information collection polling strategy and proposes an intelligent polling algorithm based on Markov chain. This algorithm can dynamically adjust the intervals according to the parameters of equipment. Experimental results show that compared with traditional equal-time polling algorithm, the algorithm can describe the data change feature more exactly while decreasing the collection distortion degree and network bandwidth, and has higher efficiency and reliability.
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Computer Engineering. 2010, 36(9): 109-110. https://doi.org/10.3969/j.issn.1000-3428.2010.09.037This paper improves the TPSN synchronization algorithm in order to achieve the purpose of continuing improving the accuracy of synchronization. In order to improve the accuracy of algorithm, it presents two improved algorithms, one is to calculate the average value among some synchronization data to overcome the impact of noise, another is to use the linear regression method to consider the impact of offset time. Experiments show that both of them can improve the synchronization accuracy while not changing the original synchronization mechanism.
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Computer Engineering. 2010, 36(9): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2010.09.038Aiming at the problem of the high synchronization packets costs in typical algorithms, this paper proposes a Low-power Clustering-based Time Synchronization(LCTS) mechanism. It combines unidirectional broadcast synchronization mechanism and bidirectional pair-wise synchronization mechanism, a new clustering algorithm is proposed at the basis of hierarchical network structure to extend LCTS to multi-hop network, and it estimates and compensates the clock drift. Simulation results show that LCTS can reduce the consumption of synchronization packets significantly without causing any synchronization lag as well as ensure the high synchronization accuracy.
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Computer Engineering. 2010, 36(9): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2010.09.039In geo-location-based Ad hoc network, the maintenance and query cost of Quorum-based location service model is high. Aiming at this problem, this paper proposes an improved Mesh Quorum-based Location Service(MQLS) model, consummates the relative selection and handover algorithm for location service and management node. The simulation results of NS2 show that improved model keeps good query success rate and query path length.
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Computer Engineering. 2010, 36(9): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2010.09.040Aiming at the multi-link switch-in problem, the link cost and routing hop which mainly affects network performance are chose as the optimal objects of multi-link egress path selection. A multi-objective optimization model is set up. The multi-link egress path selection is transformed into dynamic programming problem. Accordingly, a multi-link egress path selection algorithm based on dynamic programming is presented. Simulation results show the algorithm can promote network performance and cut down network link cost.
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Computer Engineering. 2010, 36(9): 120-122,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.041A control mechanism based on Ternary Content Addressable Memory(TCAM) and TCP rate is introduced. The P2P flux detection and control method for gigabit link is researched. On this basis, a PM model is presented. The PM model uses high precision feature matching method to identify P2P data packets. According to the probability, P2P data packets are given up randomly, which controls high bandwidth P2P flux. Simulation results show this model can effectively control the P2P flux according to the discarded probability and improve Quality of Service(QoS) for non-P2P application.
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Computer Engineering. 2010, 36(9): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2010.09.042In order to solve the problem of low efficiency of structured P2P semantic routing process, this paper analyzes the Hash function, concludes and applies the property that the logical relation among the destination node, the traditional semantic routing relay node sequence, and the clustering neighboring nodes. It proposes the self-organizing clustering P2P semantic routing algorithm to improve the efficiency of semantic routing, and guarantee the equivalence, self-organization and the possible of scaling scale of P2P network.
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Computer Engineering. 2010, 36(9): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2010.09.043Aiming at the problem that the image should be permutated before it is shared, based on (t, n) threshold multi-secret sharing theory, a non-permutated image secret sharing scheme is proposed. It makes use of the n+1 participator’s secret shadow as a gene to participate in sharing and recovering. The gap between the adjacent pixels is increased effectively. This scheme doesn’t need added secret key transmission. It is easy to be extended and the size of each shadow image is reduced to 1/t of the secret image. Experimental result proves this scheme is feasible.
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Computer Engineering. 2010, 36(9): 129-130,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.044This paper proposes a guess attack method on Trivium based on chosen differential. By analyzing the key generation equations of Trivium and determining 52 bit of its interior state which need to be altered, and then fault injections are used to alter these 52 bit and a faulty key stream can be obtained. The difference between the faulty key stream and the original key stream is computed, so that it only need guess 45 bit to make 177 nonlinear equations of key stream generation equations become linear equations. With the addition of 66 original linear equations, the rest 243 bit can be obtained by gauss elimination, thus Trivium is broken.
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Computer Engineering. 2010, 36(9): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2010.09.045Aiming at shortages of little capacity of embedded information, bad robustness and low secrecy for existing hiding algorithm, this paper proposes an improved information hiding algorithm based on PDF417 barcode. The algorithm goes on spread spectrum and map hiding information, according to self-structure feature of PDF417, and then information is hidden into micro-barcode by modifying the configuration of bar and space. Experimental results show that this algorithm had better extraction ratio to attack of printing scan and damage.
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Computer Engineering. 2010, 36(9): 134-135,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.046Aiming at the requirement that an stream cipher should have a good self-correlation, this paper proposes the concept of multinomial relation bias. Through access to the linear terms of key stream, by using Gauss elimination method, 9 multinomial relation polynomials of Trivium are found and the max bias can reach to , which is obtained by probability test. The difficulty of distinguishing attack on Trivium is illustrated.
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Computer Engineering. 2010, 36(9): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2010.09.047A new technique of gray image encryption and hiding based on a large enough symmetric host image using double random phase encoding technique is proposed. Double random phase encoding is implemented on the original image. According to the property of the symmetric image, the real and imaginary parts of the encoding image are hidden in the corresponding subimage of an absolute symmetric host image. Simple extracted and decryption operations can be employed to obtain the reconstructed image without distortion. Experimental results show that in the context of knowing the keys, it can extract the hidden image losslessly just using small weight value.
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Computer Engineering. 2010, 36(9): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2010.09.048Aiming at the problem that malware detection method based on signature can be easily subverted by obfuscation techniques, this paper proposes a detection method based on Critical Application Programming Interface Graph(CAG). By statically extracting nodes with critical API calling from Control Flow Graph(CFG) for each malware, each malicious behavior can be presented by one CAG. A matching algorithm based on CAG is used to determine whether a suspicious executable programming has the same malicious behavior as a malware does. Experimental results show that the method can detect malware variants efficiently with low false negative rate.
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Computer Engineering. 2010, 36(9): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2010.09.049In order to realize selective attributes disclosure in Automated Trust Negotiation(ATN), by using the thoughts of content extraction signature and W3C XML encryption and signature standards as technical basis, a credential description scheme is designed to support fine-grained property protection function, which makes the receiver be able to check the integrity and signature of the credentials after encryption or removal. Compared with Selectively Disclosing Sensitive Attributes(SDSA) scheme, the new scheme is simpler, more flexible and has less calculation.
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Computer Engineering. 2010, 36(9): 145-146. https://doi.org/10.3969/j.issn.1000-3428.2010.09.050This paper proposes a multiple grade and multi-proxy signature scheme to protect agents’ identity based on RSA signature scheme. The producing center of shadow identity gives every agent a shadow identity to sign for messages, which ensures that agents’ identity can not be divulged, and the authority can ask producing center of shadow identity to trace back to the true identity of an agent when he abuses his power. Security analysis shows that the scheme has the properties of non-repudiation and distinguish ability, and it can not be faked up.
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Computer Engineering. 2010, 36(9): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2010.09.051Aiming at the wormhole attack in Ad Hoc network, according to Optimized Link State Routing(OLSR) protocol, this paper presents a HELLO Interval Distributed Algorithm(HIDA) to detect fake neighbor. Simulation results show that HIDA has wormhole attack detection rate above 80% when network average node number is greater than 4, node random maximal migration rate is greater than 2 m/s.
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Computer Engineering. 2010, 36(9): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2010.09.052To enhance network communication detection of Trojan program, this paper designs and realizes a Trojan communication detection system based on NDIS Hook drive on the base of comparing advantages and disadvantages of various packet capture technology. It gives main modules and data structures, proposes Trojan communication identification model based on network communication behavior analysis technology. Test results show that this model can decrease false positive rate and negative positive rate, acquire all network communication data packet and identify new Trojan communication.
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Computer Engineering. 2010, 36(9): 153-155,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.053To solve the problem that scan item is incompleteness and quantitative assessment is insufficient, this paper brings qualitative and quantitative analysis into host assessment, proposes an assessment model based on multivariate data fusion and hierarchical analysis. It combines consistency check by adopting value engineering and judgment matrix, scans and assesses system from 11 kinds of aspect and 36 kinds of item. Application of FoundLight host security assessment system results show that this system is function complete, performance stability and operation simple.
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Computer Engineering. 2010, 36(9): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2010.09.054Detector generation is the key step of Negative Selection(NSA), but current detector generation algorithms exist redundancy detector and the lower efficiency, aiming at this problem, this paper improves detector generation algorithm, adopts the second tolerance in order to decrease the cross-cover area of non-self spaces for random generation detector, introduces the mechanism of mutation to decline the collision probability between randomly generated detector and self. Experimental results show that improved algorithm is superior to NSA algorithm for detecting Probe attack and DoS attack.
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Computer Engineering. 2010, 36(9): 159-160. https://doi.org/10.3969/j.issn.1000-3428.2010.09.055In order to prevent sub-secret transmitting in public channel, this paper proposes a secret sharing scheme based on intractability of discrete logarithm and commutativity of modular exponentiation. Results prove that participants choose their own private keys by themselves, they avoid cheating of dealer, decrease the computational cost of dealer and ensure the reusability of this scheme, moreover trusted participant may join or leave the group to ensure the dynamic of this scheme.
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Computer Engineering. 2010, 36(9): 161-162,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.056This paper proposes an efficient and adaptive Distributed Key Generation(DKG) scheme based on discrete logarithms and quadratic residue problem. It is able to dynamically add and remove members from the group by refreshing the public parameter without altering the public key. The sub-keys of each group members can be reused. It improves the efficiency of the cryptographic system.
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Computer Engineering. 2010, 36(9): 163-167. https://doi.org/10.3969/j.issn.1000-3428.2010.09.057This paper realizes note recognition method based structure mode for multi-voice music score. In the procedure of primitive extraction, three kinds of algorithms based on run-length coding are proposed respectively for extracting stem, note head and beam, they have better ability for resolve troublesome anti-intersection and anti-conglutination. In the procedure of structure analysis, interaction field is introduced to describe the association relationship of primitives, and note is divided to six kinds of substructures to reduce primitive searching range. It subdivides note structure based on aforesaid procedure, note primitive is realized recombination which follows the principle of giving priority to the key substructure, it can reduce analysis complexity and has well ability of primitive redundancy debugging. Experimental results show that this method can recognize note in multi-voice with high accuracy and efficiency, and powerful adaptability, it has good adaptability at the situation of notes intensive arrangement and complicated structure.
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Computer Engineering. 2010, 36(9): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2010.09.058Aiming at how to effectively deal with the ElectroEncephaloGram(EEG) signal and extract useful information, this paper decomposes the collection of experimental EEG with wavelet packet transform and reconstructs the relevant frequency band signal, thereby extracting β-wave rhythm from EEG signal which can be used to identify the emotional states, and analyses it in different emotional states with spectral analysis. Simulation results show that the β-wave rhythm in EEG signal used to identify the emotional states is feasible.
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Computer Engineering. 2010, 36(9): 171-172,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.059Aiming at defects of vehicle crash-avoiding fuzzy control model whose membership and fuzzy rules can not be adjusted by itself, a vehicle crash-avoiding adaptive network fuzzy interference system model is presented. The hybrid learning algorithm is proposed to improve rapidity of convergence. For some linear parameters such as consequent parameters, recursive least square algorithm is used to update it. For other nonlinear parameters such as premise parameters, steepest descent method are used to identity it. By comparing the simulation result and experiment data, it shows that the membership function and fuzzy rules for fuzzy control model is optimized effectively by using adaptive network fuzzy inference system. It has a good and self-adaptive performance for vehicle auto-control under the dangerous condition.
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Computer Engineering. 2010, 36(9): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2010.09.060In order to resolve the combination problems of Web Service for complicated tasks, a model of Web Service emergence based on immune-learning is proposed. Dynamic combinations and service emergence are realized by auto-finding, negotiating, combining or composing and executing of Web Service based on immune principle and learning mechanism in the model. Experimental results prove that the model has the abilities of learning, memory and evolution to resolve complicated tasks by auto-combining Web Service, and has good flexibility and auto-adjusting ability.
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Computer Engineering. 2010, 36(9): 176-177. https://doi.org/10.3969/j.issn.1000-3428.2010.09.061Pseudoamino Acid(PseAA) composition can incorporate influence factor of a protein sequence, so as to remarkably enhance the predictive accuracy rate. The feature of PseAA composition is selected as the input of the neural network to make a model of classifying and predicting the protein third structure. Particle Swarm Optimization(PSO) algorithm optimizes the parameters of the neural network. A new classifying method named one vs. others binary classifier is introduced. Two hundred and four protein sequences studied by Chou is used as the dataset. Experimental result is tested by the rigorous Jackknife cross validation and it shows the method can improve the predictive accuracy rate.
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Computer Engineering. 2010, 36(9): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2010.09.062In order to estimate the non-Gaussian linear acyclic causal models with latent variables, a new algorithm is proposed. The algorithm is derived by integrating penalty functions which satisfy the Oracle property into overcomplete Independent Component Analysis(ICA), making the entries of mixing matrix sparse. Experimental results show that the algorithm improves accuracy and efficiency of the casual model estimation.
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Computer Engineering. 2010, 36(9): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2010.09.063Existing Artificial Immune System(AIS) for recognition applications in the text, the detector generating algorithm for different genes, such as the quality of treatment, there can not be the optimal response gene frequency in the antibody deficiency. This paper proposes the concept of degree of gene dominant through the detector generation algorithm and the matching algorithm introduces genes dominant degree factors to improve the efficiency of the algorithm. Experimental results show that the introduction of dominant degree of the detector generating algorithm can be reduced by 30% of the time complexity.
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Computer Engineering. 2010, 36(9): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2010.09.064As to the inefficiency of evading irregular obstacle in traditional aircraft evading strategies, a flock control strategy based on dot-like β Agent is studied. On the base of accelerator input, the dot-like β Agent is defined based on the notion of β Agent, along with which the avoidance of α Agent’s own projection on the obstacle is transferred into avoiding the dot-like β Agent as assumed, and the coordinate of β Agent together with relative vectors in the (α, β) protocol input of the accelerator is modulated. After that, the multi-Agent is able to shape flock in case of irregular obstacles. Simulation result shows that an algorithm under the model of dot-like β Agent is to render effective evading in case of irregular obstacles.
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Computer Engineering. 2010, 36(9): 187-189. https://doi.org/10.3969/j.issn.1000-3428.2010.09.065A novel method based on three-layer virtual image generation for face recognition with single sample is presented. Singular Value Decomposition(SVD)-perturbation is used to highlight the facial features, and the method of geometric transformation is used to enhance the changes of attitude and scale. The number of sample is increased. The method based on spatial distribution is used to improve the distribution of samples, so that the virtual sample distribution is more close to the real-world distribution. Experimental results carried on ORL face database validate the efficiency of the method.
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Computer Engineering. 2010, 36(9): 190-191,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.066In order to solute the shortest path problem in the large networks, a clustering algorithm based on ant colony optimization is analysed. According to ant colony algorithm and clustering algorithm combining the idea, using the large-scale network is separated into several small networks to deal with later after the synthesis as well as directly in the process to simplify network approach. Transparency of the optimization algorithm meaningless points, thus simplify the calculation, improve computational efficiency. Experimental results show that the optimization algorithm can accurately obtain the required optimal solution, and has a faster convergence speed.
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Computer Engineering. 2010, 36(9): 192-194. https://doi.org/10.3969/j.issn.1000-3428.2010.09.067To overcome the disadvantages of Particle Swarm Optimization(PSO) algorithm such as premature, bad convergence precision, a new improvement scheme is presented. In the new algorithm, random inertia weight is used, and at each iteration, the particles which may fall into the local extremum area are randomly initialized renewedly in an effective method. The numeric experiments of seven classic benchmark functions indicate that the new algorithm greatly improves the particles’ ability of searching global optimal value, and has good results in higher dimensions.
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Computer Engineering. 2010, 36(9): 195-196. https://doi.org/10.3969/j.issn.1000-3428.2010.09.068Cloud wall around typhoon center is concentric-circle-liked cloud band, and its gray scale is stable usually. Aiming at this feature, this paper uses infrared cloud images to intelligently locate typhoon center. It presents a three-step location method which includes pre-process of cloud image, extraction of contour points of typhoon cloud wall based on Snake active contour model, circle fitting based on Least Square(LS). Experimental results show that this method has fast location speed, high precision, and it can satisfy the real-time requirement of weather service.
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Computer Engineering. 2010, 36(9): 197-199,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.069TF-IDF as one of feature weighting schemes in Vector Space Model(VSM) is widely used and makes good results in the realm of text categorization. Although traditional algorithms consider about term frequency and inverse document frequency, Term Frequency/Inverse Document Frequency(TF-IDF) is oblivious to the term distribution information among and inside class. A new feature weighting algorithm based on the improved IDF and distribution coefficient is put forward to enhance the feature weighting of high frequency and homogeneous distribution in the same class. Experimental results show that compared with the conventional TF-IDF algorithm, f1 based on TF-IIDF-DIC raises by 6.79%.
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Computer Engineering. 2010, 36(9): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2010.09.070This paper discusses a text categorization approach based on features vote, which is linear as well as high efficient. It uses the trust mechanism theory to analyze the trust relation between features and document classes, and gives the model to calculate the trust values. In the comparison experiments, Newsgroup, Fudan Chinese evaluation data collection and Reuters-21578 are used to evaluate the effectiveness of the techniques. Experimental results show the method can improve the performance for text categorization, and is suitable for large-scale text categorization.
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Computer Engineering. 2010, 36(9): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2010.09.071To detect and remove the scratch line which is common on old movies, spatial-temporal property in the same frame and adjacent frame is analyzed. After analyzing causes of emergence and characteristics of scratch line and basic principles of differential operation, a scratch line detection and restoration algorithm based on spatial-temporal features is proposed. Experimental results show that the algorithm can effectively detect the scratch line on old movies, and be able to accurately fix the missing data where scratch line original exists. Old movies have a better visual effect after restoration.
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Computer Engineering. 2010, 36(9): 206-207,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.072A voxel-less sectional plane reconstruction method for freehand 3D ultrasound is proposed. By computing the geometrical relationships between the B-scans and the sectional plane, the sectional plane is got directly from nearby pixels in the B-scans. The SDW method is used in calculating the gray level of the sectional plane pixels. Experimental results show that this method is more accurate and has a similar noise, reducing ability as conventional reconstruction methods, with a reconstruction time of only about 1.6% of traditional method for a given plane.
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Computer Engineering. 2010, 36(9): 208-211. https://doi.org/10.3969/j.issn.1000-3428.2010.09.073Based on the theory of panoramic image, the cylindrical panorama generation technology is studied and implemented. The cylindrical orthogonal projection and back projection algorithm based on horizontal plan is used. An adapted threshold Sequential Similarity Detection Algorithm(SSDA) is used to match images based on traditional sequential similarity detection algorithms. The bilinear interpolation algorithm is used to merge images after comparing with the nearest interpolation algorithm. Experimental results show that, the generated panorama obtains good visual effect after these series of steps.
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Computer Engineering. 2010, 36(9): 212-213,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.074Aiming at the multiphase segmentation problem of 3D image, this paper proposes a variation level set segmentation method. It gets level set function evolution equation when energy functional gains minimal value by variation method and gradient decent method, and composes a alternative implicit process with parameter estimation based on locale model. Simulation results show that this method is simple and efficient, it can quickly realize outline segmentation and reconstruction of 3D image and truly information reflecting collecting sequence fault image.
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Computer Engineering. 2010, 36(9): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2010.09.075This paper proposes an improved mixed-noise removal method for color images based on Pulse Coupled Neural Network(PCNN) which has linear attenuated threshold and weighted averaged gray level output to solve the noise blotches problem with the estimation of noise pixels achieved by analyzing the features of mixed-noise and fire-time matrixes. Mixed-noise removals for various color images are implemented with the proposed algorithm and the experimental results demonstrate its validity.
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Computer Engineering. 2010, 36(9): 217-218,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.076This paper proposes an improved method based on Jacquin theory to against the tradition way. It reduces encoded block number through classifying blocks with detail block and non-detail block, shortens encoding time and enhances compression rate in small scale block. Experimental result displays the number of encoded block reduces to 1/3 and the encoding time reduces to 2/3.
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Computer Engineering. 2010, 36(9): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2010.09.077This paper presents an automatic elastic registration of medical images based on Rényi entropic minimum spanning graph and multi-quadric radial basis function. Images are layered and blocked based on image pyramid process and its sub-image blocks are registered using Rényi entropic minimum spanning graph’s similarity measure. Landmark points in corresponding sub-image blocks are extracted. Those landmark points are interpolated via multi-quadric radial basis function so as to achieve elastic registration of medical image. Experimental results indicate that the method is a fast, accurate and effective elastic registration of image.
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Computer Engineering. 2010, 36(9): 222-223,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.078MP3 uses MPEG-1 Layer Ⅲ audio codec standard, as its high compression ratio and low distortion, the on time decoding algorithm is complex and needs more internal memory. Aiming at the above problem, this paper optimizes some complex algorithms, when 16 bit fix point Digital Signal Processor(DSP) implements MP3 decoding algorithm. It appropriately allocates the static and dynamic memory, transfers the dynamic data to external memory by Direct Memory Access(DMA) for dynamic memory. By overlap memory and removing redundant data, the storage of static memoryoan be reduced. With the improvement of decoding rate, the storage of internal memory decreases to 15.9 KB from more than 40 KB.
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Computer Engineering. 2010, 36(9): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2010.09.079H.264/AVC enhances the coding efficiency and image quality at the cost of a high computational complexity. By analyzing the Coded Block Pattern(CBP) and the correlation of neighboring modes, a fast inter mode selection algorithm is proposed. The information contained in CBP and the correlations of neighboring modes are analyzed to gain the mode classification that the optimization mode belongs to, thus decreases the number of mode need to be calculated. Experimental results show that the coding time reduces about 58% without obvious PSNR and bitrate change.
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Computer Engineering. 2010, 36(9): 227-229,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.080A method for removing duplicates among teleplays and movies is presented. Titles of these network videos usually presents distinct features which make it possible to extract videos’ names automatically by means of exact pattern matching and regular expression matching algorithms. The extracted names is processed further into regular expressions against which up-coming video titles are matched so as to accomplish the goal of removing duplicates. Experimental results show this method achieves an accuracy ratio of 97.30% and a recall ratio of 93.63%.
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Computer Engineering. 2010, 36(9): 230-231,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.081Shot boundary detection is important component of content-based video indexing. For detecting shot boundary efficiently from different video, this paper presents an efficient method for shot boundary detection. It gets the shot comparability matrix by histogram differences, according to the different characteristics of abrupt change and gradual change shot in Affinity Propagation clustering results, detect shot change by twin-comparison. Experiment results show that the algorithm can detect shot boundary automatically and fast from video information distribution.
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Computer Engineering. 2010, 36(9): 232-234,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.082The classes of objects are specific in most practical applications, an algorithm of multiple objects video segmentation with recognition information is proposed. The algorithm learns feature dictionary of object and background from training data, and constructs a hierarchical conditional random field model via computing super pixel for video frames, by which the local and global neighboring constraints in video frames are modeled. The final segmentation results are obtained by solving the hierarchical conditional random field model. Experimental results illustrate the algorithm can segment the objects of both occluded each other and the partial objects.
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Computer Engineering. 2010, 36(9): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2010.09.083The paper proposes an improved cross search algorithm, considering the direction of moving vector. The algorithm designs a directional search pattern, and adopts a series of skills, which are composed of prediction of initial search point, half-stop criteria, search pattern and auxiliary search points to reduce search points. Extensive experiments conducted based on the H.264 encoding platform show that the improved algorithm can increase the searching-rate while keeping the similar PSNR.
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Computer Engineering. 2010, 36(9): 238-239. https://doi.org/10.3969/j.issn.1000-3428.2010.09.084Aiming at the problem of clamping mold because of mold products staying in mold cavity in the process of injection molding, this paper proposes a solution, which applies digital image acquisition, processing and pattern recognition, and the mold monitoring system is developed for plastic injection to solve. Images are processed by applying self-adaptive threshold segmentation algorithm, pattern matching is analyzed by applying. Image difference detection algorithm, the compensation algorithm with search space and similarity measurement technique is used to correct the tilted image automatically by using the edge detection technique. Result shows that the ratio of qualified products is improved from 90% to 99%, the utilization rate of injection molding machines is increased from 75% to 96%.
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Computer Engineering. 2010, 36(9): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2010.09.085Aiming at receiving problem of high-rate signals, this paper proposes a communication receiver system based on cluster computing, the hardware and software architecture, the key technologies of the system are introduced, including high-speed A/D conversion, parallel data dispatching, efficient load-balance algorithm, gigabit Ethernet even output 155 Mb/s, and supporting for heterogeneous nodes and parallel processing of different kinds of signals. Practical tests show that the receiver can work at a sample rate up to 100 MSPS, a network dispatching rate up to 200 Mb/s and a signal bandwidth up to 40 MHz and can receive various high-rate communication signals in real-time.
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Computer Engineering. 2010, 36(9): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2010.09.086
Aiming at the desigh problem of the homing missile man-in-the-loop fight control system, the method of combining Vega/Creator virtual simulation with the flight control system design is brought forward. According to the operator’s operation, the data from the stick device are real-time dealt with, the closed homing system including kinetics of human body is adopted, so the man-in-the-loop system design is formed. Simulational result shows that the adaptive capacity of flight control system can be inspected and the parameters of control system can be designed by means necessary experiments, the man-in-the-loop design problem is solved.
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Computer Engineering. 2010, 36(9): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2010.09.087In order to enhance the efficiency of application in soil and water erosion, water conservation and watershed hydrological analysis based on Geographic Information System(GIS), this paper designs a new slope Length and slope Steepness(LS) factor algorithm. It uses forward-and-reverse algorithm instead of original cumulative slope length algorithm to obtain LS factor at regional landscape scales. Experimental results determine that the new algorithm makes the computer run efficiency increase within sacrificing accuracy.
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Computer Engineering. 2010, 36(9): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2010.09.088This paper proposes a tree vector decompressor, which is a complete binary tree where a node is an XOR gate. In the proposed decompressor, its small number outputs are determined by most of its inputs. And the confirmed relationship between the structure and its outputs is similar to the distribution probability of care bits in scan chains. This method reduces test data volume. Experimental results show that the test data compression ratio is up to 77 times for the ISCAS’89 benchmark circuits.
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Computer Engineering. 2010, 36(9): 252-254. https://doi.org/10.3969/j.issn.1000-3428.2010.09.089To solve the problem of low speed and large logic resource consuming in 16-bit high speed multipler design, Wallace tree structure combined with several methods such as Booth algorithm, 4-2 compressor with Carry Save Adder(CSA), and reasonable adding, padding and deleting of the signed number are used to optimize the whole design. Under 1.8 V supply and 25℃ condition, the multiplier is synthesized in SMIC 0.18 μm technology with Synopsys Design Compiler with a 3.16 ns maximal path delay and a core chip area of 50 452.75 μm2. The power dissipation is 5.17 mW.
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Computer Engineering. 2010, 36(9): 255-256. https://doi.org/10.3969/j.issn.1000-3428.2010.09.090Aiming at the development efficiency problem of embedded system, through modeling research of V850E/MS1-sim system structure, this paper proposes and implements an instruction set simulator V850E/MS1-sim for V850E/MS1 processor with high efficiency. It is composed of instruction-set, memory manager, interrupt system and I/O, ard adopts instruction-set simulation and serial simulation. Emulational result shows that V850E/MS1-sim ensures simulating precision and improves simulating efficiency.
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Computer Engineering. 2010, 36(9): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2010.09.091A protective relay test device based on Fast Fourier Transform(FFT) algorithm is designed. In this system, double CPU(host CPU and slave CPU) are adopted. Host CPU adopts MCU which is mainly used to display the man-machine interface and carry argument input. Slave CPU adopts Digital Signal Processor(DSP) which mainly runs the FFT algorithm. In the double CPU system communication between host and slave, CPU uses the principle of share memory in parallel communication. By means of applying message control mechanism, it reduces the interrupt times and increases the real-time performance of test.
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Computer Engineering. 2010, 36(9): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2010.09.092This paper presents the design of Linux drivers, a RapidIO bus driver under Linux’s hierarchical structure, including the global layer, the bus layer and the device layer, and elaborates on each layer. RapidIO end device driver and global shared memory are carried out. It gives the realization of its key processes and interface functions, and analyzes global shared memory to achieve. Analysis of experimental data shows RapidIO transmission efficiency.
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Computer Engineering. 2010, 36(9): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2010.09.093Pointing at the complexity of time unified and terminal system’s hardware architecture of the shooting range, this paper improves the original solution of the design technique of IRIG-B decodulation and system control, in terms of project implementation. Under the premise of observing GJB, it simplifies the hardware structure and innovates in design of system. It realizes the practice of integrated design time unified and terminal system based on FPGA’s Nios Ⅱembedded processor, and finishes decoding IRIG-B code(DC and AC).
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Computer Engineering. 2010, 36(9): 266-267,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.094According to the morphological character and growth feature of shepherd’s purse root system, a 3D modelling method based on the geometrical modelling is proposed. Topological and geometrical structure of shepherd’s purse root system is employed. SimRoot, a geometrical modelling of root systems, is applied. Graphics library OpenGL on the Visual C++ platform is used to establish a visual simulation system which can vividly simulate the growing process of shepherd’s purse root system. The simulation result shows that the proposed method is of validity and feasibility.
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Computer Engineering. 2010, 36(9): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2010.09.095Research on unknown network protocol reverse parsing is of great significance in many network security applications. This paper describes the existing circumstances of protocol reverse extraction technologies, and analyses two main reverse extraction methods, one based on network trace and the other one on data flow analysis. A method based on dynamic binary analysis is presented, which aims at extracting the main protocol fields of a single message by using DynamoRIO platform to implement data flow recording and analyzing.
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Computer Engineering. 2010, 36(9): 271-273. https://doi.org/10.3969/j.issn.1000-3428.2010.09.096Through analyzing the motion of blast wave, the Navier-Stokes equations are reasonably simplified. According to the main properties of blast wave, which is revealed by the simplified Navier-Stokes equations, a diffusion model is proposed to describe the motion of blast wave. The impact of blast wave is simulated by controlling the motion of fragments propelled by the blast wave based on the diffusion model. Experimental results show the method can achieve strong sense of reality and meet the real-time requirements.
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Computer Engineering. 2010, 36(9): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2010.09.097Aiming at the issue of product structure’s semantic matching, the similarity measurements between trees are analysed, a semantic and structural similarity measurement for product structure is proposed. Based on the XML model of product structure tree, the weight mechanism of expressing the product structure semantic information is discussed. The algorithm model is established, and its pseudo-codes are designed. Analysis results show it can measure product structure similarity effectively at the premise of product structure semantic constraints.
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Computer Engineering. 2010, 36(9): 277-278,. https://doi.org/10.3969/j.issn.1000-3428.2010.09.098The characteristics and defects of master-slave dual-management sub-system in the Air Traffic Control(ATC) system is analyzed. A design method of application-level dual-management system based on detection Agent is proposed. In the system model, the service, application process and resource for real-time monitoring and management technology is used to achieve the load balancing function. Experimental result shows the method improves the availability and reliability of the system.
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Computer Engineering. 2010, 36(9): 279-281. https://doi.org/10.3969/j.issn.1000-3428.2010.09.099The embedded firmware simplification method for iSCSI protocol is researched. An embedded iSCSI communication protocol prototype without Operating System(OS) support is proposed. The embedded iSCSI initiator finite state machine model is set up, which is easy for smoothly taking over the OS kernel mode initiator. The simplified protocol is integrated into IP-SAN extension BIOS, and applied to client host with no local storage devices. It achieves network boot based on IP-SAN.
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Computer Engineering. 2010, 36(9): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2010.09.100In the design and development of USB camera drive based on embedded system, it should make full use of USB bus bandwidth and ensure a high and stable data transfer speed between memory and peripherals. In order to meet the real-time video capturing requirements, reference is made to open-source projects GSPCA/SPCA5xx, recommendation of Linux kernel is adopted, and using double-URB strategy and MMAP mapping mechanism to maximize the video capturing speed, eventually realizes this USB camera drive in line with Video4Linux on the S3C2440AL_ARM development platform and provides a functional verification and performance analysis.
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Computer Engineering. 2010, 36(9): 285-287. https://doi.org/10.3969/j.issn.1000-3428.2010.09.101According to the characters of Web forum site such as the complex structure and quickly updating contents, an algorithm of forum incremental information sampling is presented. The technologies of site map rebuilding and estimating the frequency of page update are used. According to the site map, the crawler selects effective links. According to the frequency of Web page update, the crawler determines the crawling frequency of the Web page. Experimental results indicate this method is effective.
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Computer Engineering. 2010, 36(9): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2010.09.102This paper improves the traditional Direction Of Arrival(DOA) estimation method with subspace fitting. The Singular Value Decomposition(SVD) of the data matrix is employed to replace the Eigenvalue Decomposition(ED) of the covariance matrix which is estimated by the received data snapshots. The singular values and singular value vectors accomplish the estimation for the number of the impinging signals, and the covariance matrix estimation is avoided to mitigate the computation load and estimation error. The 2D Modified Varying Projection(MVP) algorithm is illustrated according to the principle of the 1D MVP. The estimation of the 2D DOA is adopted on the received signal based on the uniform circle array.
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Computer Engineering. 2010, 36(9): 291-封三. https://doi.org/10.3969/j.issn.1000-3428.2010.09.103According to the different network monitoring requirements of multiple equipments and servers in Radio Frequency Identification (RFID) information network, the common character and feature of network components are researched. The monitoring parameters are designed and selected including common parameters and special parameters. A kind of Simple Network Management Protocol(SNMP)-based Manager-Agent monitoring model is used. A general monitoring system including MIB node, Agent and monitoring tool for RFID information network is developed. Test results show the system can monitor both RFID readers and code resolution servers.
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