20 October 2009, Volume 35 Issue 20
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Computer Engineering. 2009, 35(20): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.20.001This paper analyzes the fuzzy characteristic of multi-objective n person stochastic cooperative games on the basis of relevant theory of fuzzy mathematics, constructs the model of multi-objective stochastic cooperative games and gets its interval-valued fuzzy stable set of stochastic cooperative games. Considering that the concrete benefit distribution can be realized at the end of cooperation, an interval potential value of payoff based on constructed interval-valued fuzzy stable set is proposed. And a practical example is provided to illustrate the validity and feasibility of this method.
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Computer Engineering. 2009, 35(20): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.20.002Aiming at the alignment and assembly problem of reads from the new ultra high-throughput sequencer——Solexa sequencing instrument, a new algorithm Short Read Mapping Algorithm(SRMA) for short sequence alignment and assembly is proposed, which uses hash algorithm for reference sequence and exactly locates reads on reference sequences as three segments with high speed. Method of De novo assembly is carried ou to reads which can not be aligned. Test results show that SRMA algorithm has higher performance and sensitivity, and good application future.
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Computer Engineering. 2009, 35(20): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2009.20.003According to the problem that it is difficult for traditional algorithms to get disparity of less textured pixels, a novel stereo matching algorithm based on texture analysis is proposed. Different from the existing approaches, less textured and similar pixels are integrated into line segments along a polar line. Line segments are matched based on smooth and unique constraint. The disparity of less textured area is obtained after the disparity of line segments is calculated. The novel algorithm increases the comparative information and decreases the searching range, so that it is able to reduce probability of matching errors and time complexity of algorithm. The Experimental results indicate that the proposed algorithm can improve the matching speed and the disparity accuracy of less textured area, and it is practical.
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Computer Engineering. 2009, 35(20): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2009.20.004The necessity and feasibility of polarization Remote Sensing(RS) system for Unmanned Aerial Vehicles(UAV) in China are briefly analyzed. With system’s integrated method, polarization RS payloads system for UAV is designed based on the UAV development. The system composition and workflow are introduced, including software and hardware. With successful joint debugging on the ground, result shows that the system can satisfy the operational requirements for further aviation.
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Computer Engineering. 2009, 35(20): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2009.20.005The paper proposes to use the Total Variation(TV) algorithm to eliminate the labeled objects in the satellite cloud images. The shapes of labeled objects are often long and narrow. The main effort focuses on improving the process of discreteness for the total variation algorithm through introducing different weights. The improved algorithm fulfills that it only fills the eliminating areas according to the surrounding information but keeping the surrounding information unchanged. The experiments show that the proposed method is effective for eliminating the labeled objects in the satellite cloud images.
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Computer Engineering. 2009, 35(20): 16-19. https://doi.org/10.3969/j.issn.1000-3428.2009.20.006To provide graphs generating service for flight delay predicting platform, a graphic component package is designed and implemented. It can be used to automatically generate simulation graphs of flight delay propagation DAG, advanced Petri net, Bayesian network, parallel cellular automata, and statistical graph such as bar graph. The graphic component package consists of an outer layer service and a kernel engine. The outer layer service generates graph XML document, the kernel engine pareses it and renders graphs. The graphic component package exposes its interfaces through Web services and uses XML as data exchange media to improve interoperability. It shows that the graphic component package can effectively meet the requirement of graphs generating and representing of the flight delay predicting platform.
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Computer Engineering. 2009, 35(20): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2009.20.007This paper gives a new Digital Rights Management(DRM) model to resell right. The model brings the consumer’s economic interests into the industrial chain, balances the interests between content provider and user, and incites the consumer to play legal content. A new protocol using Identity Based Encryption(IBE) and re-encryption scheme to implement this model is designed. Security and economic interests of this model are analyzed.
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Computer Engineering. 2009, 35(20): 23-24. https://doi.org/10.3969/j.issn.1000-3428.2009.20.008An approach of distributed conflict detection supporting concurrent design is proposed. The distributed conflict detection system is designed and developed. The system which is based on consistent interval solving algorithm of constraint networks can detect conflicts in product design process effectively by computing feasible intervals of design parameters in constraint networks. The B/S architecture is adopted in the system, which can support design work of geographically distributed teams. An application of the approach in the engineering design of the bogie is introduced to show the validity.
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Computer Engineering. 2009, 35(20): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2009.20.009Aiming at the node localization problems in Wireless Sensor Network(WSN), a novel node localization algorithm for WSN based on the algorithm similar to class Kamada Kawai graph drawing algorithm is proposed. The algorithm transforms node localization problem in WSN to graph drawing problem, and uses classical graph drawing algorithms to find the optimal solution of the graph drawing problem, which finishes localization. Simulation experimental results show this algorithm converges fast and can achieve high localization accuracy and better performance.
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Computer Engineering. 2009, 35(20): 28-29. https://doi.org/10.3969/j.issn.1000-3428.2009.20.010Characteristics of the domestic and foreign gearbox test system are researched. Based on information, networking and flexible requirements of advanced automobile gearbox, relying on a gearbox assembly line project, for its test loop line, a parallel structure with the automatic gearbox test line is presented, and the design of the control system based on DeviceNet is made. Many intelligent control methods have been studied for the test line. The system has entered a practical application, and it can achieve the transmission of the gearbox performance test and data analysis after test.
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Computer Engineering. 2009, 35(20): 30-33. https://doi.org/10.3969/j.issn.1000-3428.2009.20.011Aiming at the problem of multi data link co-existence and the status of developing like chimney, multi data link inter-connection gateway is designed in order to improve the ability of UAV interoperation and its cooperation with other platform. Multi data link inter-connection tactical message STANAG 4586 is designed, and adopted by UAV interoperation interface standard of USA. The message translation and interface communication are programmed under the embedded real time multi task environment VxWorks. Simulation experiment proves that the gateway meets its function and has high real time characteristic, and it is a reference for the study of the multi data link inter-connection and related technology.
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Computer Engineering. 2009, 35(20): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2009.20.012In order to parse the data files kept by Outlook directly, its internal code and logic structure are analyzed, and a PST file parsing method based on OLE automation technology is proposed. By starting Outlook automatic server, the corresponding object is set up. The post information is got by using relevant interface function provided by Outlook. Experimental results show this method can get better effect.
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Computer Engineering. 2009, 35(20): 37-40. https://doi.org/10.3969/j.issn.1000-3428.2009.20.013Aiming at data exchange between unstructured information Word data table of information systems and Relational Database(RDB), this paper proposes an interoperability method of Word data table based on PIA and ADO.NET techniques. This method solves the data conversion problems between Word table and RDB by operating Word table through Word PIA object and adopting strategies such as data extraction, data standardization inspection, virtual table definition, sub-paragraph injection and table customization. It realizes volume data importing implemented from Word table data to database and data exporting supported from database to Word data table. The feasibility and practicality of the method is verified through application cases.
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Computer Engineering. 2009, 35(20): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2009.20.014A new sensitive rule hiding algorithm, including two processes of Weak Association Transaction(WAT) and Strong Association Transaction(SAT), is presented based on the devotion degree of transactions to the mined association rules. For the two types of simple rules and composed rules, four item modification methods are designed for the updating of selected WATs. Experiments demonstrate that the direct substitution method has smallest side effect, and only a few transactions are required in data updating to hide the rule successfully. The robustness to the support attack is satisfying with suitable hiding rate. When the modification factor is set above 0.07, the hiding rate can always be 100% in rule detection process.
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Computer Engineering. 2009, 35(20): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2009.20.015Aiming at the problems of memory leakage and memory overflow in embedded software, this paper proposes a cross-test method on embedded Linux platform, in which data collection and test are separated to improve the test efficiency. A dynamic memory detection tool is implemented, which can be used to detect memory leakage, memory overflow and mismatch of memory manage function. An instance is presented to show the effectiveness and reliability of the tool.
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Computer Engineering. 2009, 35(20): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2009.20.016In order to improve the quality of profession software and shorten the development cycle, this paper proposes the Rapid Application Development Framework(RADF) based on JavaEE. RADF provides the paradigm for tiered development and the classes for the default behavior expected in the general profession application software. The proprietary behavior can be constructed via extending these classes provided by RADF, which greatly reduces the development cost. The practice shows that the line of codes can be reduced by 30% at least for the median-size profession software development based on RADF.
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Computer Engineering. 2009, 35(20): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2009.20.017Matching algorithm of sentence template can only be used in the sentences that have some divided words between the parameters, which is a technique for text analysis based on characters. So this method has its own limitations. In light of these problems and the background of question answering system, this paper presents a new method that combines with matching algorithm of lexicon, which improves the traditional method. In practice, result shows that the method can extend the range of question interpretation and enhance the accuracy of question interpretation.
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Computer Engineering. 2009, 35(20): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2009.20.018This paper analyzes the Object Relational Mapping(ORM) component——NHibernate that use extensively currently. Aiming at the shortage of NHibernate, it puts forward improved ORM model, designs and realizes a lightweight ORM component——MYPL based on .NET platform according to this model. It makes use of the component does not need to be write any mapping document to realize data lasting operations such as object relations mapping and so on, and reduces between the service level and the data level coupling enormously, enhances the system’s extendibility, maintainability and the application system development efficiency.
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Computer Engineering. 2009, 35(20): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2009.20.019Aiming at the puzzle that the models of Unified Modeling Language(UML) is short of exact formal description so it can not be analyzed and verified, the paper puts forward an improved modeling measure named UML-OCPN. It integrates the merit of UML and OCPN of Petri nets. It uses UML to model systems, changes UML models to Petri nets models, and verifies the Petri models. Experimental result proves that the problems of difficult verification and the need of developers’ upper math knowledge and so on can be solved by this means.
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Computer Engineering. 2009, 35(20): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2009.20.020The comprehensive evaluation technology of satellite mission schedule algorithm is researched. An AHP-based measurement system is set up. The evaluation model based on AHP algorithm and Delphi algorithm is introduced. According to different targets, several existed schedule algorithms are evaluated. Their applied ranges are demarcated. The results of this evaluation can be practically employed in selecting algorithms while scheduling and engendering more algorithms. It has the value of application.
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Computer Engineering. 2009, 35(20): 62-65. https://doi.org/10.3969/j.issn.1000-3428.2009.20.021In order to discover potential interesting patterns at low levels of support, aiming at problems in traditional support degree-based mode discovering algorithm, this paper proposes a hyperclique mining algorithm based on improved Relim algorithm. It splits a transaction into two or more transactions and compresses the same transactions. By using the idea of Relim algorithm, the hyperclique pattern is mined. Simulation experimental results show this algorithm can promote the mining efficiency for hyperclique pattern.
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Computer Engineering. 2009, 35(20): 66-67. https://doi.org/10.3969/j.issn.1000-3428.2009.20.022The conflict of data structure and heterogeneous representation between different data sources makes it becomes a difficult problem to query heterogeneous data sources under distributed environment. This paper proposes a multi-table query translation algorithm under distributed environment. This algorithm decomposes the source query during query transition process, transforms and reconstructs target query on the target data source, and solves the problem of multi-table query transition problem in data sharing. Experimental results show that the algorithm is effective.
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Computer Engineering. 2009, 35(20): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2009.20.023Hardware transient faults can cause control flow errors and corrupt the normal execution process by altering the operand and opcode of instructions. Aiming at the program control flow errors caused by hardware transient faults, this paper proposes an instruction-level control flow detection method to tracking program execution path. Experimental results of faults injection indicate that the average value of fault detecting rate of this method is 97.8%, and the average memory overhead and performance overhead are only 83.2% and 52.9%.
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Computer Engineering. 2009, 35(20): 71-72. https://doi.org/10.3969/j.issn.1000-3428.2009.20.024When the dataset size is huge, both the memory usage and computational cost of FP-Growth algorithm are expensive. This paper proposes a parallel algorithm, which is designed to run on the PC cluster. This algorithm finds all the conditional pattern bases of frequent items by the projection method. It splits the mining task into number of independent sub-tasks, executes these sub-tasks in parallel on nodes and aggregates the sub-results back for the final result. Experiments show that this parallel algorithm not only can accelerate the computational speed, avoids the memory overflow, but also achieves much better scalability than the FP-Growth algorithm.
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Computer Engineering. 2009, 35(20): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2009.20.025As data warehouses grow in size, how to assuring the performance of answering Ad Hoc queries on massive data becomes a big challenge. To address the issue, this paper proposes a parallel data warehouse architecture, HDW, built upon PC cluster. It employs Google’s GFS, Bigtable to process the distributive storage management and MapReduce to parallelize OLAP computation tasks. In addition, it provides the XMLA interface for front-end applications. Experimental results conducted on an 18-node cluster show that HDW scales well and can process large data sets with at least 10 million tuples.
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Computer Engineering. 2009, 35(20): 76-77. https://doi.org/10.3969/j.issn.1000-3428.2009.20.026Persistence technology of Java Database Connectivity(JDBC) based on SQL and object-oriented persistent technology based on Object/Relation Mapping(ORM) make the system in high coupling. Aiming at such problem, this paper researches Java Persistence API(JPA) ORM technology, JPA model and JPA interfaces, designs and implements a flexible data persistence model, which uncouples with ORM framework and reduces the coupling of the system, so that it is easy to develop object persistence and accelerates the developing speed of application systems.
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Computer Engineering. 2009, 35(20): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2009.20.027Discussing the deficiency of component model for mobile distributed environment currently, this paper presents a context-aware component model, Mobile Distributed Environment Trusted Component Model(MDETCM), for mobile distributed environments with combining reflection and software-contact technology. It gives a concrete instance of this model and conduct performance test. Results show that the success rate of task implemented by component is enhanced.
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Computer Engineering. 2009, 35(20): 81-82. https://doi.org/10.3969/j.issn.1000-3428.2009.20.028This paper analyzes a great deal of charge data that a supply heating company provides. It establishes a data mining model for customers by constructing a data warehouse and using the data generalization, and finds out some association rules from the frequent itemsets and some features of time to pay by using decision tree, so that it can draw a conclusion that different customers have different custom of charge. It evaluates the model and gives four suggestions on the charge strategy used in actuality.
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Computer Engineering. 2009, 35(20): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2009.20.029The performance of text categorization algorithm based on centroid is poor when the documents are dispersive or existing more than one peak value. Aiming at this problem, this paper proposes an improved text categorization algorithm whose performance is higher than classical categorization algorithm based on centroid. Experimental results in the documents set provided by Wisers Information Limited show that this algorithm can obtain satisfactory efficiency and precision.
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Computer Engineering. 2009, 35(20): 86-87. https://doi.org/10.3969/j.issn.1000-3428.2009.20.030This paper discusses the application of granular computing in association rules mining. Through partition of information granules and map of granule object sets, the algorithm reduces the object sets required when scanning datasets, and improves the running efficiency, so that it can deal with the association rules discovery of massive dataset better, and it is more suitable for the dataset with small support and high complexity. Experimental results show that the algorithm has low computing complexity and high efficiency.
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Computer Engineering. 2009, 35(20): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2009.20.031Describing the Web service using domain ontology and matching Web service on the semantic level is a hot research spot. After analyzing the disadvantage of traditional approach for semantic matching, an improved matching algorithm which adopts semantic distance and match coefficient is proposed. A prototype system based on this method is implemented. Experimental results show that this algorithm can improve the precision of match degree of service.
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Computer Engineering. 2009, 35(20): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.20.032In order to improve the concurrency processing performance and response time of Agent in EMS/Agent centralized management, this paper proposes an efficient NE Agent architecture. It uses lightweight Job to replace task as the smallest units of system schedule, and combines with multi-threaded asynchronous mechanism to improving parallelism. At present, the technology has been successfully applied in ZTE’s optical transmission equipment and effectively improved the parallel processing capacity and interactive response time of the system.
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Computer Engineering. 2009, 35(20): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2009.20.033An algorithm for Voice-over-Internet Protocol(VoIP) is proposed, because schedule algorithms guaranteeing Quality of Service(QoS) are not defined in IEEE 802.16e. The algorithm adopts extra-bandwidth allocation policy and compensation scheme. It allocates the extra-bandwidth according to the flow’s priority. The lagging flows are compensated according to services it has lost. Simulations results indicate that the difference in services between the flow received in actual system and in ideal system is almost equal to zero.
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Computer Engineering. 2009, 35(20): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2009.20.034A kind of topology aggregation algorithm suitable for multi-domain Wavelength Division Multiplex(WDM) optical network is proposed according to its characteristics. The algorithm constructs full-mesh topology with original topological graph. Full-mesh topology is furtherly compressed into asymmetric star. Simulation with randomly generated networks shows that the algorithm can effectively compress information with a little loss of accuracy. The complexity after compression can be lowed to O(N) compared with full-mesh topology.
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Computer Engineering. 2009, 35(20): 100-102. https://doi.org/10.3969/j.issn.1000-3428.2009.20.035This paper analyzes data transmission characteristics of the radio Wireless Sensor Network(WSN). Based on this, the best energy transmitting power which can make the largest network life is gained, and a policy is put forward to prolong network life and keep a high rate of data collection. Theoretical analysis result shows that the strategy ensures end-to-end under the premise of the reliability of the network and extends the life of WSN, which can play the important instructing role for WSN.
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Computer Engineering. 2009, 35(20): 103-105. https://doi.org/10.3969/j.issn.1000-3428.2009.20.036Aiming at the problem of unbalanced traffic schedule in multiple logical links, a traffic schedule model of logical links is analyzed, and the method of available bandwidth measurement is proposed. In order to depict the load of logical links clearly, the concept of maximum proportion of available bandwidth is drawn. The amount of traffic which is scheduled in special logical link is calculated. Experimental result shows that the algorithm has better ability of traffic schedule, optimizes the character of traffic load balance in multiple logical links and improves the utilization of logical links.
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Computer Engineering. 2009, 35(20): 106-108. https://doi.org/10.3969/j.issn.1000-3428.2009.20.037In order to reduce the power consumption, IEEE 802.16e proposes an idle mode energy saving mechanism. According to the operation mechanism of the idle mode, a Geom/G/1 queue with setup time and multiple vacations is built. The performance measures of the queue model are obtained by using an embedded Markov chain method. Some performance measures are derived for idle mode in IEEE 802.16e. The dependency relationships between the system performance measures and the system parameters are compared by numerical examples and simulation results.
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Computer Engineering. 2009, 35(20): 109-111. https://doi.org/10.3969/j.issn.1000-3428.2009.20.038In wireless sensor networks routing protocol, cluster-based routing has the characters of good expansibility, simple data aggregation, energy efficiency. A Cluster Director Path Multi-path Routing algorithm(CDPMR) is proposed on analysis of other multi-path routing algorithm. Simulation shows that CDPMR can be more extendable, lower overload and good stability than other multi-path routing algorithms. Comparing to other cluster-based routing algorithms, the algorithm can get more steady topology, reduce communication cost of rebuilding, and can balance network’s energy consume, prolong the networks life.
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Computer Engineering. 2009, 35(20): 112-114. https://doi.org/10.3969/j.issn.1000-3428.2009.20.039Aiming at the problems that for the existed synchronization schemes in Wireless Sensor Networks(WSNs) have a main drawback that they only correct the clock offset, a novel clock synchronization scheme is proposed to integrate clock offset synchronization and clock rate synchronization. In this scheme, single-hop synchronization is based on three consecutive message transmissions, and multiple-hop synchronization is based on a layered spanning tree. Simulation experimental results show this scheme can achieve longer resynchronization period and less synchronization error than existed ones.
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Computer Engineering. 2009, 35(20): 115-116. https://doi.org/10.3969/j.issn.1000-3428.2009.20.040In order to improve accuracy of identification traffic based on flow features, a new method of Traffic Identification Based on Information Entropy(TIBIE), which uses information entropy to find the notable features, and cascades clustering according to the notables features are put forward. Experimental results show that both the flow and byte accuracy rate of this method achieve 90% or more, which increase about 10% than the method that only based on K-Means clustering algorithm.
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Computer Engineering. 2009, 35(20): 117-120. https://doi.org/10.3969/j.issn.1000-3428.2009.20.041Router’s alias recognition is an important step in generating router level topology. Existing tools for alias recognition use an active probing approach, they induce traffic overhead into the network and depend on the response of the routers. Aiming at this problem, this paper proposes a novel approach called ABR. The method utilizes the common IP address assignment scheme to infer router’s alias from the path traces collected by traceroute tool. Experimental results show that the new method significantly improves the precision and efficiency compared to existing approaches.
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Computer Engineering. 2009, 35(20): 121-122. https://doi.org/10.3969/j.issn.1000-3428.2009.20.042This paper presents Service Unit Network Architecture(SUNA) and the Micro Communication Element System(MCES) based on non-layered network architecture. It is a problem worthy of the efforts to test the efficiency and to further validate the feasibility and validity of SUNA based on the mainframe prototype of MCES in progress. This paper discusses the approaches and processes in the performance test of the mainframe prototype of MCES based on delay and makes necessary analysis of the results which indicate that SUNA and MCES are reliable and feasible.
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Computer Engineering. 2009, 35(20): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2009.20.043This paper proposes a QoS unicast routing scheme with Always Best Connected(ABC) supported. It uses the interval to describe the user QoS requirement and the edge (link) parameter and introduces the user satisfaction degree and the edge evaluation. With the help of the gaming analysis and based on the small-world optimization algorithm, it tries to find a QoS unicast path with the Pareto optimum under the Nash equilibrium on both the network provider utility and the user utility achieved or approached. Simulation research results show this algorithm is effective.
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Computer Engineering. 2009, 35(20): 126-127. https://doi.org/10.3969/j.issn.1000-3428.2009.20.044In order to evaluate the reliability of Mobile Ad hoc NETwork(MANET), an effective method combining the network reliability with the factor of dynamic routing is proposed. The algorithm of MNRR(MANET Routing Reliability)is brought forward, which is helpful to improve the network reliability. Experimental results show the method is effective. The results of the theoretical analysis are in agreement with those based on a traditional metric, such as the packet delivery ratio obtained by numerical simulations. More specifically, the results show that the approach is suitable for feasible routing and works always significantly in large networks.
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Computer Engineering. 2009, 35(20): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2009.20.045Universally Composable Symbolic Analysis(UCSA) framework is a new method based on formal analysis and UC framework to analyze security protocols. This paper extends UCSA framework based on predecessors’ contribution, defines the ideal functionality and formal definition of sender’s non-repudiation protocols and analyzes whether the two are identical under the UCSA framework by simulation and execution trace analysis. The result shows that the ideal functionality and formal definition are identical under UCSA.
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Computer Engineering. 2009, 35(20): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2009.20.046In view of secure protection problem of backup data, this paper designs a transparent encryption mechanism of backup data for disaster tolerance based on cascading file system. In this mechanism, it uses transparent encryption function based on virtual disk. When it reads data, it encrypts. When it writes data, it decrypts. Thus, it implements data disaster tolerance, and at the same time, it enhances the encryption protection of backup data. It protects the integrity and confidentiality of data.
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Computer Engineering. 2009, 35(20): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2009.20.047Aiming at security problems in software restructural download of embedded system, a secure start-up flow for restructural embedded system is designed. The management mode of hardware storage is researched. The code co-processor is integrated and implemented. Simulation experimental results show this flow can identify the validity of system download software, and when the code is legitimate but malice, it can guarantee the chip security.
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Computer Engineering. 2009, 35(20): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2009.20.048In order to transfer the stream ciphers algebraic attacks problems into low-degree annihilators of Boolean function problem, the characters of Boolean function is discussed. The special structure of matrix on {0,1} is introduced. The relations between them are researched. On this basis, the relations between the annihilator polynomial power number of n-variant Boolean function and their support points sets are studied. Experimental results show the problem of searching annihilators for Boolean function is the same as searching the maximum affine space in zero points sets of it.
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Computer Engineering. 2009, 35(20): 140-141. https://doi.org/10.3969/j.issn.1000-3428.2009.20.049According to the properties of the function in the first pass and the order of the message words in HAVAL algorithm, a preimage attack on the compression function of the first 104-step HAVAL is proposed by using the exhaustive search method. The complexity of the attack is 2224 hash function valuations with the storage of 238 Bytes. However, the complexity of brute-force to find preimage is 2256. Analysis result has some new light on the evaluation of the security of HAVAL.
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Computer Engineering. 2009, 35(20): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2009.20.050Aiming at the serious destructiveness of geometrical attack to digital watermark, this paper proposes a geometrical attack resisted watermark algorithm. This algorithm hides the watermark information among Harmonic-Fourier moment variation of the image. The watermark sequence can be extracted by comparing the Harmonic-Fourier moment of the attacked image with the key during the watermark detection. Experimental results show that the algorithm is robustness to rotation attacks, scaling, JPEG compression and other noise attacks.
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Computer Engineering. 2009, 35(20): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2009.20.051The principles of statistics about randomness tests are introduced. Sixteen common randomness tests are provided, as well as the processing flow of randomness tests towards cryptography. The layout methods of tests ID are discussed. These methods are used to test the standard of NESSIE——Camellia algorithm. Experimental results show high randomness on the cipher generated by reduced-Camellia at least three-round.
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Computer Engineering. 2009, 35(20): 148-150. https://doi.org/10.3969/j.issn.1000-3428.2009.20.052On the basis of Role Based Access Control(RBAC) model, combining with the application properties of XML, the permission’s informations of system and users are processed separately by XML and database. This paper designs and implements a method of permission management in Web systems based on XML and database technology. The method increases flexibility and reusage of permission management in Web systems. It examines realistically by the system in existence.
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Computer Engineering. 2009, 35(20): 151-152. https://doi.org/10.3969/j.issn.1000-3428.2009.20.053Aiming at the application and security problem of authentication protocol in restriction communication environment, this paper presents an authentication protocol based on elliptic curve cryptographic techniques, in which data confidentiality of exchanged information is supported by symmetric cryptography. The conversation key shared by participants is generated in the end of the protocol. Formal anlysis is done on recommended protocol by using extended SVO logic and the security of the protocol is proved by the results.
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Computer Engineering. 2009, 35(20): 153-156. https://doi.org/10.3969/j.issn.1000-3428.2009.20.054This paper analyzes the hiberarchy of eXtensible Markup Language(XML) document. Based on XML sub-element permutation and combination, an information hiding algorithm is presented. This algorithm changes secret information to a decimal integer and creates equal element by permutation and combination of sub-element. According to mapping relation between equal element and integer, the integer is embedded into the XML document by changing the element to its equal element. Experimental results and analysis show that the algorithm does not change the size of XML document, and has better imperceptibility and robustness and larger information hiding capacity than existing XML document hiding techniques. The algorithm can be used to protect the content of a XML Web page and covert communication.
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Computer Engineering. 2009, 35(20): 159-159.User-mode encryption system with low security needs much interaction and the device drive encryption system compacted with operation system is complex in design and realization in general. A method based on file system filtering drive of Windows NT kernel to achieve the security of confidential data is proposed. The method can be used to encrypt storage data dynamically and transparently, and decrease the user’s interaction and support multi-file system. The security and performance of this encryption system are compared with Windows Encrypting File System(EFS).
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Computer Engineering. 2009, 35(20): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2009.20.056Aiming at the drawbacks of traditional packet capture mechanism such as redundantly memory copy, frequently interrupt handle and context switch, this paper proposes the idea that control the packet transmission in user space, uses real-time Linux kernel and zero-copy to reform the NIC device driver. The throughputs of new packet platform result for 64 Byte and 1 500 Byte are 473 Mb/s and 947 Mb/s. Experimental result proves that compared with the traditional platform, the new platform gets a remarkable enhancement on performance.
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Computer Engineering. 2009, 35(20): 163-164. https://doi.org/10.3969/j.issn.1000-3428.2009.20.057Aiming at the construction problems of the certificateless signature with special properties, the construction methods of certificateless message recovery signature is researched. By analyzing the properties of the cetificateless signature and the message recovery signature, the first certificateless message recovery signature scheme in the certificateless cryptosystem is implemented. With the knowledge signature of discrete logarithm, it is proved this scheme is secure under the DL assumption in the random oracle model.
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Computer Engineering. 2009, 35(20): 165-166. https://doi.org/10.3969/j.issn.1000-3428.2009.20.058Cryptanalysis of a traitor tracing scheme shows that it exists follow security deficiencies: the revoked traitor can decrypt new ciphertext under the help of legitimate user; legitimate users can forge effective decryption key if they conspire. This paper proposes forgery attack scheme and gives the reason why it is attacked. This paper points out one mistake in designation of the scheme, which explains it is not feasible in the actual operation.
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Computer Engineering. 2009, 35(20): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2009.20.059A Cellular Automata(CA) model is developed aiming at spread of the worm virus in network. The spread process of virus is divided into two stages and different model for different stage is built. In simulation process, a great deal of information about the number of worm virus, computer system with different state and the trend of virus spread can be obtained. It is shown that the CA model can show a clearer trend for virus spread and produce simulation similar to the actual worm virus spread.
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Computer Engineering. 2009, 35(20): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2009.20.060Boolean functions play important roles in coding theory, combinatorial design and sequence design. A class of Plateaued functions is gotten by way of using the Maiorana-McFarland construction. Combined with the characteristic of the state transform matrix of m-sequence, a class of (n+1)/2-dimension Plateaued functions with n variables is constructed. A variety of cryptographically desirable criteria for multi-dimension functions can be satisfied, such as high nonlinearity, nonexistence of nonzero linear structures, balance and the highest algebraic degree.
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Computer Engineering. 2009, 35(20): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2009.20.061Aiming at the demands of automatic classification of vehicles, by introducing the description method in spatial morphology of Geography Information System(GIS), this paper presents geometric parameters, calculation methods of the side view of the vehicles and geometric feature parameters, and combines feature geometric parameters for vehicle-type classification. With the geometrical features of the side view, it gives a method to extract vehicle axle parameters automatically, and designs a vehicle classifier based on geometric feature parameters. This method is proved to be effective by experiment.
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Computer Engineering. 2009, 35(20): 176-177. https://doi.org/10.3969/j.issn.1000-3428.2009.20.062This paper presents an objects recognition method under given object size and same view point situation, that locally segments the same size window with the template by search the target image, then segments the template, and gets the intersection between template and the searched window. By matching the common pixels between the searched windows and the template via searching the whole image, it maximizes the correlation coefficient or select several maximums, best matching patches gotten.
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Computer Engineering. 2009, 35(20): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2009.20.063This paper proposes a news story segmentation method based on Naïve Bayes model. It gets the candidate boundary points through shot detection, extracts multi-modal middle-level features at the boundary points such as visual, audio type, motion and caption to generate a feature set as the input of the model, and uses trained Naïve Bayes model to classify the candidate boundary points. After post-processing upon the result, the non-news parts are removed and the news parts are saved. Experimental results show that the method is effective and adaptive to the different kinds of news programs, and it achieves satisfactory precision and recall.
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Computer Engineering. 2009, 35(20): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2009.20.064This paper presents reconstruction method of Gene Regulatory Network(GRN) based on Modified Particle Swarm Optimization (MPSO). It uses PSO to identify the optimal architecture and parameter of the weight matrices model, so that a recurrent neural network consistent with experimental data is inferred, and uses weight matrices model to simulate GRN. Experimental results show that the method is effective to infer complex interaction such as GRN.
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Computer Engineering. 2009, 35(20): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2009.20.065A topic sentence extraction method based on Weight Fuzzy Clustering(WFC) and Mutual Information(MI) is proposed, which is to cover more topics and lower the redundant information of the text. The abstract efficiency is promoted. Using WFC method, the sentences is classified. Sentences in each cluster is ranked by MI values. High qualified abstact is obtained. Experimental results show that, compared with former clustering method, this method can improve the precision by nearly 15%, and has about 70% accuracy. It can get text information correctly.
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Computer Engineering. 2009, 35(20): 187-188. https://doi.org/10.3969/j.issn.1000-3428.2009.20.066In order to solve the problem of long training time in face detection with Adaboost algorithm, this paper presents a fast Adaboost training algorithm. Based on original Adaboost, it uses the serialization table to select weaker classifier in training process. After a round of training, it does not update the sample weights but does the next round training by using histogram statistics, which is based on the selected classifier. Experimental result show that the algorithm gains higher training efficiency.
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Computer Engineering. 2009, 35(20): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2009.20.067It is found that some parameters should be determined by hand when using Chameleon algorithm to choose K value and the threshold value of similarity degree function. It is difficult to determine these parameters without any prior domain knowledge. Aiming at this problem, this paper introduces modularity theory and proposes a clustering algorithm——M-Chameleon according to the structural equivalence similarity degree and modularity theory. Experimental results confirm that M-Chameleon can reflect the actual clustering situation objectively.
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Computer Engineering. 2009, 35(20): 192-193. https://doi.org/10.3969/j.issn.1000-3428.2009.20.068This paper proposes a shadow detection algorithm based on edge information and illumination direction. It detects shadow which unifies through the shadow characteristics of HSV and RGB color space, estimates the illumination direction through the shadow which formerly examined, and uses the shadow detection algorithm based on edge information to detect the shadow in the threshold range of illumination direction. It can effectively detect the shadow of a moving object and remove the shadow disturbance for the following processing. Experimental results show that the algorithm is robust to noise and more efficient than traditional algorithms.
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Computer Engineering. 2009, 35(20): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2009.20.069A hierarchical Particle Swarm Optimization(PSO) algorithm is proposed in order to overcome the weak ability of local search and slowly converging speed of PSO algorithm in later period. In the algorithm, the global search and local search with standard particle swarms performs synchronously, and the local layer is decided by the better individual which is found in the global layer. A dynamic adaptive strategy of adjusting the local search space is adopted to avoid converging to local optimization, so the algorithm can retain the global convergence ability of PSO successfully. Experimental results on several benchmark functions indicate that the hierarchical PSO increases the speed of convergence and enhances the ability of local search.
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Computer Engineering. 2009, 35(20): 197-198. https://doi.org/10.3969/j.issn.1000-3428.2009.20.070The research of brain-computer interface attracts more and more interests, especially the classification and decoding of nerval activity is most important. This paper uses relevance vector machine algorithm to classify the firing rates from small populations of neurons in primary motor cortex. It uses the output of classifier to recursively infer nerval state and hand kinematics conditioned on neural firing rates. Experiments show that the relevance vector machine algorithm is suited for the classification and decoding of nerval activity, and the performance of relevance vector machine is better than the popular support vector machine and information vector machine.
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Computer Engineering. 2009, 35(20): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2009.20.071This paper proposes a hybrid method to recognize Chinese Base Noun Phrase(BaseNP), including the use of grammer rules, statistical approach and classification combination. It utilizes words information, part of speech information and context syntax information of BaseNP, generates a combination classification and improves the precision. Experimental results on CTB5.0 show that the F-score is 90.09%, it proves that the method is an effective approach to Chinese BaseNP recognition.
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Computer Engineering. 2009, 35(20): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2009.20.072At present, as the most widely used in terrain data segmentation, Level Of Detail(LOD) plays an important role to increase the speed of terrain rendering and scene visualization. Applying the most comprehensive LOD algorithm is based on quadtree. By the study of existing algorithm, this paper introduces a LOD algorithm based on improved quadtree-split and node storage. In order to expedite the speed of quadtree generation, the times of error judgment is dwindled down. And at the same time, a new node storage structure means much less redundant data stored than traditional way.
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Computer Engineering. 2009, 35(20): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2009.20.073Based on the simplification of progressive meshes, presents the triangular mesh model simplification based on edge optimization. The Level Of Detail(LOD) is continuously distributed in the mufti-resolution mesh model reconstructed by this approach, and dynamically changed with the movement of the view point. Experimental result demonstrates that the implementation of the algorithm is good effect and runs fast, it also supports the LOD model efficiently.
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Computer Engineering. 2009, 35(20): 208-209. https://doi.org/10.3969/j.issn.1000-3428.2009.20.074Locally Linear Embedding(LLE) algorithm can be used to solve image denoising problem, but when the nearest neighbor samples are nonlinear, the performance of image denoising is degraded. Aiming at this problem, this paper uses Kernel Locally Linear Embedding(KLLE) algorithm to solve image denoising problem in this paper. Image samples are mapped by means of nonlinear kernel function to high dimensional feature space, KLLE algorithm is used to solve image denoising problem in the high dimensional space, which is effective for high-dimensional non-linear image denoising problem. Experimental results show that proposed method is superior to LLE algorithm and median filtering.
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Computer Engineering. 2009, 35(20): 210-211. https://doi.org/10.3969/j.issn.1000-3428.2009.20.075High dynamic range(HDR) image is designed to depict the full visual range of the real-world scenes. Each luminance value is direct ratio to the corresponding point in the real world scenes, so the HDR image can represent the optical characters between bright regions and dark regions better. This paper presents an algorithm of compressing HDR images to fit conventional display devices that are only capable of outputting a low dynamic range. Experimental results show the algorithm of manipulating the gradient field of luminance image by attenuating the large gradients’ magnitudes can preserve fine details.
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Computer Engineering. 2009, 35(20): 212-215. https://doi.org/10.3969/j.issn.1000-3428.2009.20.076The low-level visual features(color, texture and shape) in image implicate lots of emotional semantics information with human perception. This paper proposes a new indexing scheme, called Fuzzy Recognize Degree(FRD) clustering using the texture feature. This method allows to retrieve images for emotion-assisted semantic analysis based on high-level affective concepts. For this purpose, a set of perceptual relevant features is introduced: directionality, contrast and coarseness. Collecting indooor decoration images, experimental result shows the high performance of the proposed technique.
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Computer Engineering. 2009, 35(20): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2009.20.077This paper introduces a software system, which is the data recording and qualifying monitor module of the offshore prospect seismic data acquisition system. It has a ring hierarchical architecture including software kernel, service bus, show layer, application layer and data layer. It can receive and dispose four cable(6 000 m/cable) seismic data in real-time or off line and monitor the seismic data qualifying. Real test shows that this software has a friendly interface, well compatibility, strong expansibility and high reliability.
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Computer Engineering. 2009, 35(20): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2009.20.078This paper introduces an embedded system oriented JPEG decoding coprocessor, which doesn’t need dual-port RAM and works well with Microblaze asynchronously. This decoder can decode JPEG file whose format is JFIF perfectly with few FIFO memory space by verilog. Certified in xilinx’s XUP Virtex II Pro development board, it works well through connection with Microblaze by FSL bus.
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Computer Engineering. 2009, 35(20): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2009.20.079This paper introduces a remote underwater acoustics parallel computing system. On cross platform, this system supports remote operating and running Linux system parallel program on Windows system and provids a kind of uniform mode for the applied customer to operation. Customer does not need to know the concrete structure of the parallel computing system, and can operate the parallel system and complete the computation or simulation what they need. Application results show that this system can reduce the complication on developing parallel programs, improve the efficiency on using parallel computing system, and solve the problem of real-time data transmission between server and client machine.
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Computer Engineering. 2009, 35(20): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2009.20.080This paper researches the modular avionics harmonization and the modeling/simulation of advanced avionics architectures. The blueprint concept is presented encompassing Integrated Modular Avionics(IMA) system. An exercise of its application to a reference TV-command-guided system architecture is carried out. It provides the salutary research for the TV-command-guided system transforming from the traditional architecture to IMA.
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Computer Engineering. 2009, 35(20): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2009.20.081High real time performance and high reliability are required by the embedded operating system based on OSEK standard. The quality and executing efficiency of the schedule algorithm are the keys to ensure the real time performance and reliability of the operating system. After analyzing the task scheduling mechanism of OSEK standard, the problem is solved that the lower priority task can not be scheduled long time, and a compensating schedule algorithm is introduced. Experimental result shows that this algorithm is feasible.
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Computer Engineering. 2009, 35(20): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2009.20.082The paper presents the method to complete network switch in chip of network controller in allusion to network switch delay in the redundancy backup technology of the network cards in the network communications. The network channels is switched according to the state of network channels working and data receiving circuit when datum received are decoded in network link layer. This implements the function of real-time switch when network equipment is trouble in physics layer or datum received is wrong.
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Computer Engineering. 2009, 35(20): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2009.20.083This paper introduces the scheme of a network processor. The prototype of the data processing core which is the core block of network processor verification method is described. The architecture of the prototype verification platform, the reset timing and clock synchronized for prototype verification with multi-FPGAs and the procedure of verification are discussed. Experimental result on this platform verifies the feasibility of this prototype verification method.
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Computer Engineering. 2009, 35(20): 237-238. https://doi.org/10.3969/j.issn.1000-3428.2009.20.084Aiming at the accidents caused by the awful driving environment of strip mine and the blind zone of tramcar driver, this paper uses Global Position System(GPS), wireless teledata broadcast module and 3D image control engine technology of Google Earth(GE), and develops the 3D driving assisting system for truck safety in strip mine to provide 3D reference information for drivers in strip mine and real time truck monitor information for remote dispatcher. This system can improve the driving security of truck in strip mine by customizing the 3D digital map of strip mine, tracking the 3D truck model or mark points of real time location of truck and indicating safe driving leading routes.
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Computer Engineering. 2009, 35(20): 239-241. https://doi.org/10.3969/j.issn.1000-3428.2009.20.085In order to improve the performance of Stud Genetic Algorithm(SGA) and accelerate the convergence speed, an improved stud genetic algorithm based on opposition is proposed. Conventional random method is replaced with opposition method in both population initialization and mutation, which can improve the quality of solutions. Based on benchmark functions, the optimization performance of the algorithm is compared with genetic algorithm, different evolutionary, particle swarm optimization and stud genetic algorithm, the results show that the new algorithm has better optimization performance.
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Computer Engineering. 2009, 35(20): 242-245. https://doi.org/10.3969/j.issn.1000-3428.2009.20.086GridMol is a computational chemistry system for pre-processing and post-processing, which is based on the idea of grid computing. Its main functions include molecular visualization, molecular modeling and job submission. This paper analyzes the performance issues in GridMol system and presents techniques to optimize the performance by re-organizing Java 3D scene graphs. It demonstrates the effectiveness of the techniques by comparing GridMol with another molecular visualization software.
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Computer Engineering. 2009, 35(20): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2009.20.087The current CAD software lacks of designing knowledge reuse, and most of them are based on WIMP interaction. This paper designs and implements a garment CAD system based on knowledge reuse, whose architecture includes knowledge recommendation module and knowledge editing module. In the knowledge recommendation phase, it proposes a real-time knowledge recommendation algorithm based on similarity calculation of pen sketch. In the knowledge editing phase, it provides a knowledge editing method based on pen gesture, and gives the application instance of the system. This system is used in a cashmere factory in Beijing, and the practice proves this system can improve human-computer interaction experience, and improve the design efficiency.
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Computer Engineering. 2009, 35(20): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2009.20.088Aiming at the requirement of enterprise management and control integration for enterprise scene monitor system, this paper proposes a 3 layer monitor system of mixed C/S and B/S. The C/S uses OPC technology to unify interfaces between client side and server side. The client side deploys Web Services to realize the mutual operations between B/S and C/S. Result proves that the system can well realize the information integration from field devices layer to workshop management layer combining the application of highway tunnel monitor system.
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Computer Engineering. 2009, 35(20): 252-254. https://doi.org/10.3969/j.issn.1000-3428.2009.20.089Aiming at the needs of the human resource services and management information for high school, this paper builds the human resource and relationship management platform for overall school. It uses Service Oriented Architecture(SOA). Experimental results proves the platform can integrate and share the data between heterogeneous systems, provide personalized service for human resource objects, and further upgrade the service level of business department and technical level of information system.
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Computer Engineering. 2009, 35(20): 255-257. https://doi.org/10.3969/j.issn.1000-3428.2009.20.090This paper analyses four boundary-scan test generation algorithms, including all 0(1)+01(10) parallel sequence algorithm, minimum weight and maximum dissimilarity algorithm, adaptive complete diagnosis algorithm and genetic algorithm, compares the advantage and disadvantage of each algorithm. It contrasts the test time and compact test vector through DEMO board interconnection test. Result shows that genetic algorithm is the relative best algorithm, it can generate well compactness test vector with the capacity of anti-signs miscarriage of justice.
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Computer Engineering. 2009, 35(20): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2009.20.091Based on the analysis of scientific workflow’s concept and character, this paper puts forward a uniform framework about application integration for the requirement of the application integration in scientific workflow. It describes how to abstract various applications into a uniform model on which to integrate all kinds of applications effectively. It implements a scientific workflow management system based on this model. An image processing application is used to validate the feasibility of this framework.
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Computer Engineering. 2009, 35(20): 261-263. https://doi.org/10.3969/j.issn.1000-3428.2009.20.092The iptables’ core packet classification algorithm has lower capability. Focusing on this issue, this paper presents an efficient packet classification algorithm according to the limits of the Linux kernel, as well as sufficient usage of the mechanisms in the kernel. It provides the characteristics, such as multi-dimensional packet classification, dynamic operations and quick matching, which are required by the mainstream. Experimental results show that the algorithm greatly improves the performance, especially in the condition of big rule sets.
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Computer Engineering. 2009, 35(20): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2009.20.093The communication equipments running continuously in a long time must meet the needs of real-time, reliability and efficiency, this paper proposes embedded real-time dynamic memory management mechanism aiming at the feature in communications. It can do a unified redistribution with the limited memory resources in embedded systems, distribute an independent memory space for applications which allocate and free memory frequently. Experimental result shows that the mechanism can improve the dynamic memory management efficiency in real-time, reduce memory fragments, ensure the robustness of the system, and provide a method for detecting memory overrun and memory leak.
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Computer Engineering. 2009, 35(20): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2009.20.094In order to solve the problem of collision between multi-tag in radio frequency identification(RFID) system. This paper proposes RFID anti-collision algorithm based on grouping dynamic frame slotted by analyzing frame slotted ALOHA algorithm. When there are a large number of tags in the field, it can achieve high discernment efficiency by grouping to restrict the number of response tags. Simulation results show that the algorithm improves the slot utilization rate above 80% comparing with the conventional algorithms, when the number of tag is 1 000.
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Computer Engineering. 2009, 35(20): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2009.20.095This paper surveys the major deficiency and the demand of decision support of China power enterprise group. The main contribution is to present the novel solution of the integrative ‘grid-province-city’ decision support system which is based on Service Oriented Architecture(SOA) and data warehouse architecture. The SOA is utilized to exchange data between the data warehouse and the data source systems to clear up the information island. The data warehouse architecture can implement the different types’ decision support functions. Analyse result shows that this center has better feasibility.
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Computer Engineering. 2009, 35(20): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2009.20.096Aiming at the traits of single-site Web page indexer is low index speed and serial invert index algorithm, this paper proposes a distributed parallel invert index algorithm. The algorithm applies distributed parallel to compute ProActive middleware and single index Lucene package, designs and implements distributed parallel Web page indexer. Experimental result shows it has high index performance and good scalability.
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Computer Engineering. 2009, 35(20): 276-277. https://doi.org/10.3969/j.issn.1000-3428.2009.20.097To effectively organize and analyze data within traffic management, this paper makes use of computing similarity between data set and sample set topic feature vector to filter and decide which categories the data sets belong to. All work stations work together to build index with the help of Hadoop distributed application framework. According to the category of query, the algorithm only consults correlative topic index for results to achieve a better retrieval performance.
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Computer Engineering. 2009, 35(20): 278-280. https://doi.org/10.3969/j.issn.1000-3428.2009.20.098Underwater target and buoy tracking have their own characteristics and difficulties, this paper proposes a underwater target tracking system model. It combines the resolution equations of passive time difference of arrival location with actual movement of underwater target, uses the Extended Kalman Filter(EKF) algorithm, analyses tracking problem of underwater target and the confidence ellipse for every moment. Simulation results show that the filter still can converge at the lower sampling rate, it proves the feasibility of this system model.
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Computer Engineering. 2009, 35(20): 281-282. https://doi.org/10.3969/j.issn.1000-3428.2009.20.099Aiming at the problem of traditional noise estimation algorithms based on minimum statistics and recursive averaging existing long time delay, this paper proposes a quick tracking noise estimation algorithm, it applies voice activity detection into subband spectral tracking to estimate the power spectrum of non-stationary noise. Simulation results show that the algorithm ensures the accuracy of noise estimation, it tracts faster than other algorithm when the noise is highly non-stationary.
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Computer Engineering. 2009, 35(20): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2009.20.100This paper designs a storage isolation and reversion system in order to implement two kinds of safety protection for storage isolation and reversion. It gives work principle, design scheme and implementation detail of system. The system is different from the traditional storage isolation method, it purely implements based on software, sets arbitrary number of isolated storage areas, further implements the multi point reversion function of system. Experimental result proves that the system has lower disposition cost and greater flexibility.
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