20 May 2008, Volume 34 Issue 10
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Computer Engineering. 2008, 34(10): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2008.10.001A non-cooperative power control algorithm is proposed based on the model of wireless CDMA sensor networks. A node payoff function which involved of utility function and cost function is modeled in the algorithm and the transmitting power vector is obtained by parallel update. It is proved that the sensor network can reach Nash Equilibrium with this transmitting power vector, and in this situation all the nodes’ payoff function is maximized. The OPNET is applied to simulation process of the algorithm, during which simulation has been carried out with different index combinations. Results show that the power control algorithm based on the game theory model has a very good astringency. Performance of the system can be improved through the selection of the utility factor between 1.0~1.1 and price factor between 5.5~5.9.
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Computer Engineering. 2008, 34(10): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2008.10.002Moving block technology is successfully applied in urban mass transit system, and can enhance its transportation efficiency evidently. But its practical applications have not been taken place on railway. After analyzing the complexities and specialties of moving automatic block system in comparison with urban mass transit system, this paper discusses the importance of train information moving management in railway moving automatic block system, and presents the three-stage dynamic information management strategy of train and the dynamic information management methods of sector trains based on the bidirectional link list. And the train information inquiry is studied on the basis of hierarchal concordance. This paper analyzes the associated algorithms and its performances. All these have definite value for reference to the research and the applications of railway automatic moving block system.
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Computer Engineering. 2008, 34(10): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2008.10.003The integration of grid and P2P provides a solution for the scalability of conventional grid. This paper proposes a P2P-based grid resource discovery model, which is integrated semantic and multi-Agent, to optimize grid resource discovery. In this model, resource discovery consists of two phases: intra-GridPeer query and inter-GridPeer query. Theory analysis proves that the model is more flexible and more scalable, which is more suitable for P2P Grid resources matchmaking.
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Computer Engineering. 2008, 34(10): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2008.10.004Differential Power Spectral Density Analysis(DPSDA) is a new kind of side channel attacks(SCA) approach. This paper explains data-power correlation of CMOS logic gates in the Integrated Circuits(ICs), introduces Differential Power Analysis(DPA) and Differential Power Spectral Density Analysis(DPSDA). Instead of computing the differential signals in the time domain, DPSDA is performed in the frequency domain by calculating the differential power spectral density signal. For the embedded DES encrypted systems with random delay, DPSDA can find 48-bit key of the round 1 of DES, but DPA can not.
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Computer Engineering. 2008, 34(10): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2008.10.005Most of the existing semi-supervised clustering methods neglect the structural information of the data, while the few constraints available may degrade the performance of the algorithms. This paper presents a Density-based Constraint Expansion(DCE) method. The dataset is represented by a graph. It introduces a density-based graph similarity. The constraint set is expanded by the similarity of the data samples. The expanded constraint set can be used in all semi-supervised clustering algorithms, including the constraint complete link algorithm and the pairwise constraint K means algorithm. Experimental results on several synthetic datasets and real-world datasets show that the DCE method can effectively enhance the performance of the semi-supervised clustering algorithms.
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Computer Engineering. 2008, 34(10): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2008.10.006To solve head pose estimation problem under different illumination and expression, a new pose feature is proposed, which is based on Histogram of Oriented Gradient(HOG) feature and Principle Component Analysis(PCA), and SVM classifier is used to classify different poses. The algorithm is tested based on CMU pose, illumination and expression database and CVL database. Experiment shows that the algorithm can estimate poses accurately under different illumination, and correct ratio arrives at 90%.
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Computer Engineering. 2008, 34(10): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2008.10.007An agent-based framework for message exchange in distributed game servers is presented. Based on the framework, this paper proposes message delivery algorithms that remove the unfair advantage that players with smaller message delays from the game server receive over players with large message delays from the server. The framework does not require assumptions of synchronized clocks at the players which are very difficult in Internet, and user can connect to server with lower delay jitter in order to improve fairness.
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Computer Engineering. 2008, 34(10): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2008.10.008By using the media kernel algorithms to evaluate the performance of MDS-I, the first generation media extension sets of RISC3200, it is found that MDS-I sets have powerful media data processing ability but awkward media data providing ability. The MDS-II sets for high efficiency media data provision is extended. Experimental results show MDS sets of RISC3200 can achieve about 2~5 speedups for media kernel algorithms compared with its MDF sets.
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Computer Engineering. 2008, 34(10): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2008.10.009Question parsing is one of the most important steps in the implementation of restricted-domain question answering system. This paper puts forward a new method to parse Chinese questions based on ontology and question semantic model, and explores how to use question semantic representation to represent the results of question parsing. A restricted-domain question answering system adopting this question parsing method is developed. Experimental results show that the precision of the method can exceed 90%, and it is feasible to use the method to develop restricted-domain question answering system.
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Computer Engineering. 2008, 34(10): 28-29. https://doi.org/10.3969/j.issn.1000-3428.2008.10.010Aiming at the problem of measurement level output, an information fusion algorithm based on multi-agent theory is presented. The concept of fancy judgment matrix is given, and an integration method of multiple classifiers based on adaptive weight adjusting is presented. Adaptive weight adjusting fusion method adaptively assigns weights to classifiers based on the sample. According to the experiments on standard database, this algorithm leads to less error than other methods and individual classifier. Experiments show that the algorithm is convergent.
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Computer Engineering. 2008, 34(10): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2008.10.011Profiling technique can provide accurate program execution information. But an online Profiling can only collect simple information in runtime environment due to the overhead. This paper proposes Profiling technique based on partial call graph, which can reduce the runtime overhead when collecting thread-specific profile information of multithread applications. The Profiling technique is implemented in a Java virtual machine. The experiments show its runtime overhead is only 2%~4% compared with that of old ones.
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Computer Engineering. 2008, 34(10): 33-34. https://doi.org/10.3969/j.issn.1000-3428.2008.10.012Service continuity and self-adaptive capability are the objective requests for many mission-critical systems, so mission hot-swapping technology is proposed. The basic principle of mission hot-swapping is introduced, and key technologies to implement interposition and replacement of the mission components are analyzed. Technical routes of mission hot-swapping are summarized and elementary experimental research is carried out. The experimental results show that the method has implemented the dynamic replacement of the mission components, and it can be used to improve the availability and adaptability of the mission-critical systems.
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Computer Engineering. 2008, 34(10): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2008.10.013The Agent-based technology becomes a method to solve complex and distributed problem. Software architecture is an important means to control the complexity of software systems, to improve software quality and to support software development and software reuse. Agent systems can be benefited from architectural design, which can be used as a plan to show Agents, interactions, and their organizational relationships. This paper represents a formal framework that can be used to specify the architecture of Agent systems by integrating the strength of two notations in a way that the description of a system at the higher level of abstraction defined in Diagrammatic Syntactic Theory(DST) with the concrete realization of it is represented in Hierarchical Predicate Transition Nets(HPrTNs) at a lower level of design.
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Computer Engineering. 2008, 34(10): 38-39. https://doi.org/10.3969/j.issn.1000-3428.2008.10.014Fast Update(FUP) algorithm always produces a lot of candidate itemsets and scans database many times. An improved Pruning and Fast Updating(PFUP) algorithm is presented to solve such two bottleneck problems of FUP. PFUP algorithm joins strong large itemsets into small quantitative of candidate itemsets based on strong large itemsets concept, and adopts early pruning strategy to cut down the times of scanning database. Simulation shows that the execution time of PFUP algorithm reduces to about 50% compared with FUP algorithm in the case of the same database and support.
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Computer Engineering. 2008, 34(10): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2008.10.015To solve the dynamic reverse nearest neighbor queries for the moving objects, the definition and the primary properties of the reverse nearest neighbors are proposed and the theorems and arithmetics for computing the dynamic reverse nearest neighbors using the conceptions of the distance-function and delimitation-regions are developed. To get the dynamic reverse nearest neighbors, the methods based on the distance-function and the dynamic inspect-circle are proposed. The amount of the calculation can be reduced by 40%~60%. To solve this question in the spatio-temporal database, a new spatio-temporal index tree——TPRDNN tree is presented and the arithmetics for querying the new tree are introduced.
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Computer Engineering. 2008, 34(10): 43-45. https://doi.org/10.3969/j.issn.1000-3428.2008.10.016A new secondary ordering algorithm is proposed in the middle software module of mobile search platform based on short message, which can cater for various kinds of search engines. According to the characteristics of mobile terminal such as smaller screen, weaker storing and processing ability, based on the internal similarity and external linkage degree, this algorithm totally evaluates the inquired results from search engine, and acquires the final ordering results. Experimental results based on Linux system show that this algorithm overcomes the defects of vast number of returned information and low accuracy of traditional searching engines, increases the search satisfactory factor to 63.57%, and improves the efficiency of mobile search.
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Computer Engineering. 2008, 34(10): 46-48. https://doi.org/10.3969/j.issn.1000-3428.2008.10.017A software safety demonstration test method based on the accelerating profile is developed on the basis of strictly distinguishing software safety and software reliability. This method includes the details of how to construct the accelerating profile by systematical software safety analysis. According to the method, the software safety target can be demonstrated confidently together with sharply reducing the testing cases size after the accelerating factor is derived by importance sample principle.
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Computer Engineering. 2008, 34(10): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2008.10.018This paper focuses on the key technology adopted in the data path of LionFS, which is an object-based cluster file system, including the direct data transmission mechanism and prefetch policy based on the access information of workload. Performance test results show that read performance increases by 70% with the data path pipelined by prefetch. Read/write performance increases by 24%/28% due to elimination of memory copy by direct data transmission.
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Computer Engineering. 2008, 34(10): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2008.10.019This paper studies search algorithms designed for network processor, and presents a new non-backtracking longest prefix match algorithm based on Patricia tree. The algorithm is simulated and evaluated, which is used in the searching engine design of a network processor designed by Institute of Computing Technology, Chinese Academy of Sciences. The searching engine can run at a speed of 155.9 MHz, and occupies 421 LUTs when implemented in a XC2VP30 FPGA. It can finish 7 000 000 search operations when running at a speed of 100 MHz.
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Computer Engineering. 2008, 34(10): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2008.10.020This paper proposes a policy transformation method based on knowledge base, designs the composing structure of the policy transformation, analyzes the policy knowledge and its specification, builds the dynamic and extensible knowledge base, and develops the flexible policy compiler and policy assembler. Test shows that the technology implements the intelligent policy transformation, and solves the problem that policies of various devices can not be uniformly managed.
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Computer Engineering. 2008, 34(10): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2008.10.021There are many differences between knowledge service products and realistic products. The most important characteristics of knowledge service products are: no logistics, high cost of making a match, long term business and hard to intermediate. An overview of the recent models of e-commerce is presented. Four full-lifecycle process models of the knowledge service product are given. The system architecture of the knowledge service exchange platform which is based on Service-Oriented Architecture(SOA) and Web2.0 are shown. Analysis theory shows that the platform is a scalable and reusable one, which supports dynamic processes.
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Computer Engineering. 2008, 34(10): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2008.10.022This paper proposes a new algorithm for mining frequent subsequence in time series based on symbolic representation. A dimensionality reduction technique called PAA linear segment representation is used. Under the Gaussian distribution, several breakpoints are set. The projected database is built to mine the frequent subsequence. The algorithm is simple and new, runs so fast, and reduces the cost of computing support counts of subsequences.
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Computer Engineering. 2008, 34(10): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2008.10.023To extract useful performance indicators from business process, this paper develops a new approach to monitor business process using Web Service Proxy(WS-Proxy). WS-Proxy provides a single point of service access with service mapping, message dispatching and data extracting functions. It utilizes a DFA-based algorithm developed based on YFilter for monitoring Web service messages and extracting XML elements. Experimental results show WS-Proxy achieves better performance than YFilter in processing SOAP messages.
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Computer Engineering. 2008, 34(10): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2008.10.024Complex query based on data cube is the development direction of cube technique. This paper detects three types of the dependent-relationships in complex data cube query, and proposes three methods based on cache reusing accordingly. The experiments on synthetical and real datasets illustrate the approaches proposed are efficient and promising.
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Computer Engineering. 2008, 34(10): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2008.10.025Prediction by Partial Matching(PPM) models are appropriate for predicting the user’s next request, but these models are not on-line and their updates are implemented by rebuilding models which can not meet the real-time update. This paper presents an on-line PPM prediction model based on non-compact suffix tree. The model makes use of non-compact suffix tree to implement the incremental on-line update, and its update speed is improved. This model has the important property of being on-line.
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Computer Engineering. 2008, 34(10): 73-74. https://doi.org/10.3969/j.issn.1000-3428.2008.10.026Composite pattern is a common design pattern to solve the relationship between part and whole. But it’s not easy to solve the problems in Composite pattern with OOP, such as responsibility tangling, intertwining code, bad reusability. This paper presents the implementation of Composite pattern with AspectJ by changing classes’ behaviors with AOP technology. Compared with Composite pattern with OOP, it proves that the pattern with AOP and AspectJ has better model responsibility cohesion and extensibility.
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Computer Engineering. 2008, 34(10): 75-77. https://doi.org/10.3969/j.issn.1000-3428.2008.10.027This paper proposes a kind of storage management framework based on Enterprise Volume Management System(EVMS) and Simple Network Management Protocol(SNMP). It can effectively solve the problem of how to manage the disks, segments, software RAIDs, LVM2’s VG/LVs and VSVM volumes on the storage servers of the Service on Demand(SonD) system. This paper presents two ways to implement this framework. Test results show that the performance of subagent is superior to that of MIB handler by more than 20%.
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Computer Engineering. 2008, 34(10): 78-79. https://doi.org/10.3969/j.issn.1000-3428.2008.10.028Aiming at the problem of Linux process scheduling policy just regards the system capability and neglects user service, the paper presents a kind of process scheduling policy facing user according to the discrepancy of process quantity every user owned, which invokes Linux dynamic priority scheduling policy, fair share scheduling policy and self-adapt fair share scheduling policy in order to meet the every user’s need in whole system to most degree and realize the fair principle of process scheduling. In the realization process, it settles the problem of decision-making account and introduces the dynamic right adjusting mechanism to realize self-adapting fair share arithmetic. The experimental result indicates that the process scheduling policy is effective and valuable applying on the time-sharing system which regards user’s contentment degree.
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Computer Engineering. 2008, 34(10): 80-82. https://doi.org/10.3969/j.issn.1000-3428.2008.10.029This paper analyzes the key theory and advantages of Aspect-Oriented Programming(AOP). It indicates that the aspect-oriented concepts can be promoted further to the software architecture level. By adding new elements and composition mechanism to the software architecture description language XYZ/ADL, Aspect-Oriented Architecture Description Language(AO-ADL) is proposed to capture and modularize the crosscutting concerns.
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Computer Engineering. 2008, 34(10): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2008.10.030The core module of search engines, namely indexer, is usually based on inverted file. But this solution to solve phrase-search is in difficulty(the lower hitting rate). In this paper the Suffix Array(SA) are employed for full-text indexing. In order to overcome the disadvantage of large memory cost as with full-text indexing, research is done for Compressed Suffix Array(CSA). The paper presents the step of using CSA index and the false code of core operate. The experiments show that this technique, compared with inverted file, improves the hitting rate for phrase by 20%.
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Computer Engineering. 2008, 34(10): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2008.10.031Fuzzy C means clustering is introduced to fuzzify the continuous attribute, and the best minute class number is obtained by the valid analysis of clustering. It has overcome the disadvantage of determining artificially the class number for fuzzifing attribute approach. The attribute degree of membership matrix which obtained by attribute fuzzified is used to attributes reduction, and attributes reduction algorithm based on fuzzy rough sets is given. An example is illustrated to prove its feasibility and effectiveness.
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Computer Engineering. 2008, 34(10): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2008.10.032To develop device drivers for Linux is a skillful work as it is twisted too much with kernel details. On the other hand, due to lack of the necessary reusability, a new driver has to be produced slowly. To simplify the development process and improve the reusability, this paper contributes one object-oriented framework for device drivers by introducing C++ language into Linux kernel. The framework has encapsulated the management of driver’s life and behaviors. With aids of the framework, Linux device drivers with good quality can be developed easily, quickly, and normatively.
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Computer Engineering. 2008, 34(10): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2008.10.033At present the main technology of Aspect Oriented Programming(AOP) is AspectJ based on Java. This paper discusses a new AOP technology called Eos language, which is based on .NET. Eos extends the C# language, introduces an intact syntax of AOP, and supplies a special compiler; all of these improve the performance of Eos compared with the other AOP tools. The multi-language characteristic of .NET makes cross language use of AOP possible.
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Computer Engineering. 2008, 34(10): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2008.10.034In order to give a fast attribute reduction algorithm of the consistent decision table, the condition attributes are divided into three sorts: core attribute, relatively necessary attribute and absolutely superfluous attribute. Two definitions called discernible Boolean matrix of consistent decision table and elementary row transformation of Boolean matrix are given. A model related to attribute reduction is established. Discernible Boolean matrix can be transformed into the simplest matrix by the elementary row transformation proposed in this paper. Three necessary and sufficient conditions for determining the attributes are given. A novel attribute reduction algorithm is proposed by these necessary and sufficient conditions.
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Computer Engineering. 2008, 34(10): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2008.10.035At present the steadily data share between ERP systems and other applications is still a major issue to be solved, due to the heterogeneity of networks, operation systems and database systems. The paper presents a project solution based on message-oriented middleware. In order to improve the coupling of the ERP system, the solution combines the enterprise applications based on different operation systems and databases into a unified system, and realizes the real distributing applications. This solution has been used in several large sale enterprises and can improve the security and efficiency of data transferring and the portability of codes.
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Computer Engineering. 2008, 34(10): 101-102. https://doi.org/10.3969/j.issn.1000-3428.2008.10.036This paper proposes a Clustering Algorithm of High-dimensional Data(CAHD). Unit regions with intensive data points are found by employing the two-way search strategy in the designated n-dimensional space or its subspaces, and these intensive modules are clustered by a case-by-phase approach. Two-way search strategy can effectively reduce the search space, improve the efficiency of algorithms, and cluster intensive regional unit only uses one by one with two machines and displacement direction. Experimental results show that the running time CAHD algorithm spent is 30% less than other algorithms with the same number of categories found.
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Computer Engineering. 2008, 34(10): 103-104. https://doi.org/10.3969/j.issn.1000-3428.2008.10.037INFORMIX is one of the most popular database in finance industry in China. Its configure parameters have important influence on its performance. According the result of inspect INFORMIX performance on the data warehouse system of the commercial bank, some faults in performance of INFORMIX data warehouse system are found out through a long time monitor. The paper takes some measures of system optimization in virtual process, share memory, and data extraction. The performance of the system is improved by optimization, because the method of analysis and process question is universality, and it is worthy of reference to similar system.
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Computer Engineering. 2008, 34(10): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2008.10.038
TFRC is a well-known rate-based TCP-friendly congestion control mechanism. In this work, an improved algorithm of TFRC, denoted by TFRC-CJUTD, is introduced, in order to meet the requirement of end-to-end real-time stream for network transport. Within this improved algorithm, jitters of unidirectional transport delay are proposed to be used as a feedback signal in the control mechanism in order to effectively reduce the jitters of unidirectional transport delay in course of stream transport, so that the control mechanism can better adapt to real-time stream. Remarkable improvement of this new algorithm is verified through simulations on NS.
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Computer Engineering. 2008, 34(10): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2008.10.039This paper presents a composition model capable of composing Web services across wide area networks with the service composition based on interface idea integrated with Peer to Peer(P2P) technologies. It forms a novel Web Services Composition Overlay Network(WSCON) with P2P technologies, then associates nodes in the same Web services composition domain to form the Web Services Composition Network(WSCN), according to domain ontology and its reasoning ability. Web service discovery and composition entry are performed through Distributed Hash Table(DHT). Extensive experiments are conducted by using large-scale simulations. The experimental results show the advantages of the model: supporting Web service composition based on QoS, high composition success rate, fast service distribution, discovery and composition, and tolerant to dynamic service component node arrivals and departures.
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Computer Engineering. 2008, 34(10): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2008.10.040Due to random delay during ABR traffic transmitting, network node can not be controlled steadily. A double-end cooperative congestion control strategy is proposed and analyzed. Simulation that runs on the OPNET software shows that, the strategy works well in terms of stability of the network node queue length, reduces the cells drop probability of the network node, and improves QoS of network and transmission efficiency.
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Computer Engineering. 2008, 34(10): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2008.10.041For general inter-domain algorithm, such as the classic hot-potato algorithm schedule route by intra-domain events, which intra-domain events may trigger large BGP routing changes. Although TIE algorithm(Tunable Inter-domain Egress selection algorithm) improves the sensitivity of the intra-domain, enabling it to adjust the inter-domain egress selection, which can reduce the volatility of routing, but the threshold parameter T is not given. In fact, the inter-domain neighbors events affected the inter-domain exports have an important impact on the choice, only to the research literature small. Improved Tunable Inter-domain Egress Selection Algorithm(IITE) which can adaptive adjustable inter-domain egress selection algorithm are presents, through the dynamic parameters of the adjustment to adapt to the current network load and inter-domain communication capabilities change to better meet the traffic engineering and network robustness. Simulation results show that IITE can control algorithm sensitivity, as well as inter-domain synergies with the load of traffic engineering changes on the adaptability of a reasonable compromise.
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Computer Engineering. 2008, 34(10): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2008.10.042This paper puts forward a scalable design of OSPF topology monitoring system in resource, cost, configuration and application mode to aim at the existing problems in the management of OSPF network. Meanwhile, it gives the adjacency & passive design of Link State Advertisement(LSA) collector, topology discovery and link-break detection algorithm based on LSA. The experimental result and analysis show that the new system has the features of high scalability and correctness compared with the similar systems in the large-scale network environment.
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Computer Engineering. 2008, 34(10): 120-123. https://doi.org/10.3969/j.issn.1000-3428.2008.10.043For higher capacity of the multi-service hierarchical CDMA systems, this paper represents a compensation method of traditional power control method, which is based on the prediction of power adjusting and the confidence level. Simulation proves that it is better than traditional power control method, which reduces interrupt possibility by about 15%.
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Computer Engineering. 2008, 34(10): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2008.10.044This paper addresses dynamic time slot assign mechanism. By analyzing MAC protocol in Ethernet Passive Optical Network(EPON), it proposes a new Dynamic Bandwidth Allocation(DBA) algorithm for supporting QoS. The algorithm adopts limited bandwidth allocation, priority-based scheduling and allocates bandwidth in advance for various types of traffic. Simulation demonstrates that the algorithm enhances QoS metrics such as average delay and throughputs over other protocols.
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Computer Engineering. 2008, 34(10): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2008.10.045Workflow tasks are partitioned according to the characteristic of workflow tasks structure, and the whole deadline and cost are divided into sub-deadline and sub-cost in every task partition by task length and traffic between tasks. Based on the users’ multi-QoS requirements and communication time between workflow tasks, this paper presents a trust-and-cost-based comprehensive beneficial function, a strategy of determination of trust’s and cost’s weight, and a scheduling algorithm——TCD which takes trust and cost comprehensive optimization as its objective. The multiple objective optimal scheduling of the whole is reached by pursuing part optimization. Compared with others algorithms through simulation shows that the service refuse rate of the algorithm can reduce by 15% at most and it satisfies users’ multi-QoS well.
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Computer Engineering. 2008, 34(10): 129-130. https://doi.org/10.3969/j.issn.1000-3428.2008.10.046TinyOS task scheduling is based on first-come-first-served non-preempting strategy, which is not able to give emergency tasks quick response, and throughput of nodes is lower. To address this issue, this paper proposes a new preempting algorithm, Deadline Short Algorithm(DSA): Through executing hard real-time tasks within an absolute deadline time limit, it meets system requirement for the real-time response, and improves processor’s response speed. Through executing soft real-time tasks based on shortest-job-first scheduling priority strategy, system throughput is increased. Test result indicates that with more nodes of wireless sensor network, though energy consumption has a little bit increase, it provides a high real-time performance and high throughput, avoiding network congestion.
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Computer Engineering. 2008, 34(10): 131-132. https://doi.org/10.3969/j.issn.1000-3428.2008.10.047SVM based filter can achieve higher accuracy in spam filtering. But in actual applications, it costs a lot for users to lose legitimate email. In this paper, a spam filtering method based on cost sensitive SVM is proposed. The standard SVM is reconstructed as cost sensitive learner by introducing various trade-off factors for positive and negative examples. The aim is to decrease the number of legitimate emails that are misclassified while maintain a high ratio spam recall. Experimental results show that the proposed method can enhance the filtering performance effectively.
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Computer Engineering. 2008, 34(10): 133-134. https://doi.org/10.3969/j.issn.1000-3428.2008.10.048
It is very important to get the call blocking probability quickly and accurately under the real-time call admission control. This paper proposes a new strategy of guard channels in a specifically integrated service wireless systems model. And gets the new call and handover call blocking probability quickly and accurately, when such parameters as the number of cell channels, the number of guard channels and both new and handover calls’ load are specified. The model is simulated, and results coincides well.
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Computer Engineering. 2008, 34(10): 135-137. https://doi.org/10.3969/j.issn.1000-3428.2008.10.049This paper researches the communication in Pharos Remote Monitoring and Control System(PRMCS), the topology control algorithm of the communication based on Wireless Sensor Network(WSN) is presented. Based on the characteristics of the PRMCS, the cluster mechanism is used in hierarchical topology control, and the improved Geographical Adaptive Fidelity(GAF) algorithm is used to build the communication between Remote Terminal Unit(RTU). Test of running system demonstrates that the stability communication is improved significantly, the average interval of communication is reduced by 55%.
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Computer Engineering. 2008, 34(10): 138-140. https://doi.org/10.3969/j.issn.1000-3428.2008.10.050Because of the higher loss rate of wireless sensor networks, key negotiation can not be completed only in once. A metric with higher discrimination, namely weighting secure connectivity, is proposed to research the influences of the link status of wireless sensor networks on key negotiation. By analyzing the factors of affecting key negotiation and simulating on various network models, the law of influences of link status on key negotiation is found. The simulation results and analysis show that the secure connectivity is better if the distance between nodes accounts for about two fifths of the longest communication distance.
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Computer Engineering. 2008, 34(10): 141-143. https://doi.org/10.3969/j.issn.1000-3428.2008.10.051Biometric Encryption(BE) merges biometric template and the cryptographic key together to create biometric-key. Biometric template and the cryptographic key cannot be revealed without a successful biometric authentication. BE also includes cancelable biometrics, and with that, security and privacy can be achieved. The main schemes of BE are introduced in this paper and their advantages and disadvantages are pointed out.
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Computer Engineering. 2008, 34(10): 144-146. https://doi.org/10.3969/j.issn.1000-3428.2008.10.052Digital image scrambling is one of the most important methods of image information hiding and camouflage. This paper proposes a digital image grey level scrambling algorithm based on the classical Vigenère coding theory, and presents the detailed process of this algorithm. The analysis of the simulation shows the validity of the algorithm: the similarity degree between the result’s histogram and white noise image’s is almost 0.9. By discussing the security and compared with the results of advanced grey code transformation, the proposed algorithm is proved of better practicability.
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Computer Engineering. 2008, 34(10): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2008.10.053As the development trend of trojan virus to the kernel, in order to provide anti-virus technology reference, this paper analyzes the NDIS architecture, puts forward a concealed communication method based on NDIS driver technology, designs and realizes a trojan virus model based on this method, analyzes and testes it. The result of the test proves the non-touch firewall penetration ability of the trojan model.
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Computer Engineering. 2008, 34(10): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2008.10.054By using data fusion, this paper proposes a robust digital watermarking algorithm. Multiple copies of digital watermarking are embedded into the carrier image by exploiting the characteristics of tree-structured wavelet decomposition and human visual system, and Independent Component Analysis(ICA) method can be used to extract these copies. These extracted copies are fused by PCA image fusion algorithm so as to improve the robustness of the algorithm. Simulation experiments show that the scheme is effective, and achieves higher transparency and strong robustness to common image processing attacks.
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Computer Engineering. 2008, 34(10): 153-154. https://doi.org/10.3969/j.issn.1000-3428.2008.10.055A new active steganalysis scheme which only uses one copy of stego image is presented. This paper views active steganalysis as an Independent Component Analysis(ICA) problem under the assumption that embedded secret message is an independent, identically distributed (i.i.d) random sequence and independent to cover image. With only one copy of stego image, it adoptes Maximum Posteriori(MAP) estimator to obtain an estimation of cover image and generates another two signals with the estimated version. All the three signals are as input signals of ICA algorithm. The proposed scheme overcomes the constraint of Chandramouli’s method which needs two copies of stego image. Experimental results show that the proposed method achieves acceptable performance and improves its performance with larger message length.
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Computer Engineering. 2008, 34(10): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2008.10.056Based on the bilateral and multi-issue negotiation model, a deadlock-eliminated mathematical model Is proposed, and aiming at this problem the evolution equation of the PSO is improved in order to insure the particles moving in a hyper-plane. The Improved PSO(IPSO) is used to optimize the deadlock-eliminated mathematical model and the reserved value vector of the negotiation issues is optimized to eliminate the deadlock. The results show that compared with PSO, the IPSO has better performance, uses less time, and enhances the success ratio.
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Computer Engineering. 2008, 34(10): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2008.10.057Aiming at the command and decision-making problem in Beyond Visual Range Air Combat (BVRAC), an optimal scheduling method of multi-targets BVR attacking based on ant colony algorithm is put forward. By applying the good parallel computing and fast global searching capabilities of ant colony algorithm, it makes the constructed scheduling method of multi-targets BVR attacking, which can obtain satisfaction solution to the problem in real time. The implement process is given. Simulation result shows that the method is effective, especially for large scale scheduling problem, and has faster constringency rate and higher precision.
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Computer Engineering. 2008, 34(10): 161-162. https://doi.org/10.3969/j.issn.1000-3428.2008.10.058This paper proposes a novel keyword verification algorithm based on dynamic ranking information for on-line garbage model keyword spotting systems, using ranking information of acoustics scores in the recognition process. It reduces false alarm rate effectively without lowering detection rate and gets better verification performance than others. The method does not depend on specific keywords vocabulary, is easy to calculate and can be applied to practical projects.
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Computer Engineering. 2008, 34(10): 163-165. https://doi.org/10.3969/j.issn.1000-3428.2008.10.059The paper effectively solves the problem of regulation redundancy through adopting penalty function to set up the threshold of supporting degree. In respect of niching genetic algorithm, it adopts a new prime factor chromosome encoding method and introduces the maximal frequency item distribution list. This encoding method changes the transaction originally expressed in character into the one expressed in integer and changes the character string operation into the numerical value operation and compresses the property item of the transaction database to a numerical value item. Through introducing the maximal frequency item distribution list, it can always mine in the maximal frequency item compact district and thus, it effectively prunes the assembling searchspace. Experimental results show that the adopting method makes the compressing ratio of the transaction database in excess of 25%, and the effect can increase by at least 47%.
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Computer Engineering. 2008, 34(10): 166-167. https://doi.org/10.3969/j.issn.1000-3428.2008.10.060Different attributes partitions affect about attribute significance and attributes support degree to decision attribute. This paper analyzes the relationship among data in knowledge represent system based on rough set. Generalization of system is combined to consider. A decision model is presented for generating certain control rules. Judgment and algorithm are introduced to compute attributes partitions in decision model and find relative attributes reduction in decision model. Experimental results show conciseness and efficiency of algorithms and preciseness and utility of decision model.
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Computer Engineering. 2008, 34(10): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2008.10.061Static Clonal Selection Algorithm(SCSA) is proposed to generate detectors to intrusion detection. By combining gene expression with partial match rule which is important in negative selection algorithm, this paper presents a new expression which can express classification rules with OR operator. Based on the proposed expression, an augmented SCSA is proposed. It is tested by simulation experiment for self/nonself discrimination. Results show that the algorithm with optimized match threshold spends less time and is more effective to generate detector with partial classification rules than SCSA, which generates detector with full conjunctive rules with ‘and’.
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Computer Engineering. 2008, 34(10): 171-172. https://doi.org/10.3969/j.issn.1000-3428.2008.10.062Salt and pepper noise is produced at the processes of collection and transmission of digital image. Traditional filtering algorithm can not remove the noise effectively in the high noisy rate. This paper presents a filtering algorithm with accurate noise pixels detection based on extreme and medium filtering algorithm. The algorithm distinguishes noise pixels and signal pixels through setting threshold value and considering the correlativity of adjacent pixels, so it can improve the precision of filtering. Simulation results show that this algorithm is better than other algorithms at filtering salt and pepper noise and preserving the detail of image. And the restoring effect of image is good under high noisy rate.
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Computer Engineering. 2008, 34(10): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2008.10.063An improved edge detecting algorithm based on mathematical morphology is proposed to overcome the limitation which embarrasses the performance of the traditional mathematical morphological methods. The new algorithm inherits the merit of the traditional methods, furthermore it introduces the new idea considering about the orientation of the edge. To get thinner edge in the morphological gradient graph, non-maximum suppression is adopted. After using the new edge connecting method based on gradient direction, the ultimate edge is obtained. In virtue of this new algorithm, thin and low contrast edge is figured out and the noise is attenuated. The comparison with traditional morphology detector and the Canny detector demonstrates the improvement of the new algorithm.
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Computer Engineering. 2008, 34(10): 176-177. https://doi.org/10.3969/j.issn.1000-3428.2008.10.064The conventional grey model is a kind of unbiased exponential models with the characteristics of less date, high precision and without the prior information. However, it can not get the expected results sometimes. According to the facts, an amendatory grey model (AGM (1, 1) for short) and its stages are supposed, and are used to predict the yearly total number of internal travelers in one province. Prediction results of the two above grey models are compared. It shows that the amendatory grey model is of higher precision, less prediction errors, simple process and effective practicality. AGM (1, 1) can provide scientific decision references for the concerning governments.
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Computer Engineering. 2008, 34(10): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2008.10.065In order to reduce the error and improve the image visual quality in the wavelet transform process, a new method based on adaptive lifting scheme wavelet transform is presented. The gradient information is introduced to construct the decision-making function so as to gain the update and prediction operator due to grasp the optimized wavelet base. The integer quantization method is adopt in the adaptive lifting scheme wavelet transform, and experimental result shows that the proposed method is effective.
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Computer Engineering. 2008, 34(10): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2008.10.066A multilevel sequential optimization algorithm based on Niche Immune Genetic Algorithm(NIGA) is proposed to solve the problem of optimal layout of silicon steel sheet. NIGA based on immune algorithm employs genetic operators to improve antibodies, and niche technique to increase the population diversity. The combination between genetic operators and the immune memory strategy accelerates the generation of elite. Furthermore, the global searching performance is improved, and premature is avoided because of clone restraint strategy. The algorithm is applied to practical layout problem, and the results show the effectiveness and feasibility of the algorithm.
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Computer Engineering. 2008, 34(10): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2008.10.067This paper presents a novel local feature detection and image retrieval method based on interest points. The method utilizes the location information of the interest points, and extracts the local color feature and local texture feature to express the contents of an image. Experimental results show that the method improves the average retrieval accuracy by 11 percent, compared with other interest points based retrieval method.
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Computer Engineering. 2008, 34(10): 187-189. https://doi.org/10.3969/j.issn.1000-3428.2008.10.068The common Traveling Salesman Problem(TSP) is static, but in actual life, most optimal problems are dynamic. This paper proposes the dynamic TSP, the size of the candidate city and the distance between cities may vary from time to time, while within the sample time these variables remain unchanged. That is a real time optimal problems and it is necessary to design the fast optimal tool. The fuzzy based genetic algorithm is proposed. Fuzzy rules are online extracted in the running process of algorithm, and these rules are used to adapt the parameter of genetic algorithm. Simulation results confirm the efficiency of the algorithm.
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Computer Engineering. 2008, 34(10): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2008.10.069The paper presents an improved DBSCAN algorithm for bus station cluster, which improves the degree of accuracy by shrinking the searching radius and merging the clusters by the share object. As a result it efficaciously avoids over-segmentation and reduces the number of noise points. Thus, it effectively shields the sensitivity of the input parameter, produces better clustering results, and reduces the influence to the cluster result by density disparity. And the high performance of the origin algorithm is maintained at the same time. Experimental results demonstrate by cluster of Beijing bus station. And the accuracy of cluster increasesby 16%, which indicates that improve algorithm is valid.
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Computer Engineering. 2008, 34(10): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2008.10.070This paper extracts gamers’ personal information from the database of online game and mines to find their potential demands of virtual items by BP Neural Network (NN). To solve the problem of inaccuracy caused by lacking of supervising sample using the traditional NN, an advanced BP model with initial weights in BP NN set by expertise and adjusted by the trained samples is put forward, whose result is more accurate with fewer supervising sample. Simulation results show that the model is efficient and useful.
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Computer Engineering. 2008, 34(10): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2008.10.071This paper proposes a new method to solve the problems of region-based segmentation in high-resolution remote sensing sea images in order to partition ships region from complicated background. It gets some information from wavelet transform in an appropriate proportion, does some segmentation by an improved DBC algorithm, and maps to the original image to segment in a smaller scale. Experimental results prove that the algorithms is effective.
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Computer Engineering. 2008, 34(10): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2008.10.072The whole gravel stone often has non-uniform and multi-color nature because of its complexity and variety, so it is difficult to accurately detect its edge with original method. This paper presents a high-precisioned method of segmentation named edge flow and level set to extract all the strong and weak edges. In order to get rid of feigned edges in big gravel stone, it proposes a method combining color gradient and mean-variance, which makes each edge of the stone more complete. Experimental results show that the the method is good and lays a good foundation for follow-up treatment.
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Computer Engineering. 2008, 34(10): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2008.10.073A new image retrieval method based on Radius and Angle Histograms of Color Blocks(RAHCB) is proposed. The method views image content as a set of several color blocks. The radius histogram and angle histogram of each color blocks are used to compute the similarity of images for image retrieval. Ten groups of images from Corel database are tested. It selects 20 widths of images as inquiry examples. Results show that the average rates of increase precision of RAHCB compared with color histogram and structure quantification histogram are 10.3% and 11.9% respectively.
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Computer Engineering. 2008, 34(10): 205-206. https://doi.org/10.3969/j.issn.1000-3428.2008.10.074This paper proposes a new model for image decomposition to achieve staircase reduction. The energy for the cartoon interpolates between total variation regularization and isotropic smoothing, while the energy for the texture interpolates between Meyer’s G norm and H-1 norm. These energies are dual in the sense of the Legendre-Fenchel transform and their adaptive behavior preserves key features such as object boundaries and textures while avoiding staircasing in smooth regions.
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Computer Engineering. 2008, 34(10): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2008.10.075This paper combines the immune algorithm to the traditional genetic algorithm and it reserves original algorithm superior search ability for global search and avoids poor performance of local search and precocious phenomenon. Based on the improved algorithm, the problem of delay-constrained QoS anycast routing is lubricated. The experimental analysis certificate that the improved algorithm has enhanced 18% rate of convergence, and it also has other characteristics such as a higher searching accuracy and more reliable stability, etc..
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Computer Engineering. 2008, 34(10): 210-211. https://doi.org/10.3969/j.issn.1000-3428.2008.10.076Basing on analysis of geometry feature of chip and fundament of Radon transform, this paper presents a method for detecting the geometry feature of chip based on improved Radon transform. The algorithm research focuses on detecting edge lines, eliminating the disturbing and improving performance in the boundary detection process of rectangular chip. The enhancement on the efficiency of the algorithm is about 30% proved. Experimental result shows that this algorithm is robust and the result is accurate.
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Computer Engineering. 2008, 34(10): 212-214. https://doi.org/10.3969/j.issn.1000-3428.2008.10.077This paper analyzes the theory of Harris operator, and points out its disadvantage. It proposes an auto-adaptive Harris operator based on the ideology of image break and neighboring point eliminating method. It makes the corners are well-proportioned distributing, and avoids too many corners stay together effectively. Experimental results show that the algorithm can detect corner more reasonable, and can be used in image mosaics well.
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Computer Engineering. 2008, 34(10): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2008.10.078H.264 provides several predicting modes for intra prediction in the spatial region, and the optimal mode is selected by RDO technique. That makes compression performance improved, but the complexity and computation load increase drastically. A fast intra prediction algorithm is proposed in this paper. It utilizes SAD value to decide whether 4×4 intra prediction can be skipped, and uses the block’s SATD to filter out some less probable modes in 4×4 intra prediction. Experimental results show that intra predicting time of the proposed algorithm is 69.3% less than that of H.264, with negligible loss of PNSR and increase of bite-rate.
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Computer Engineering. 2008, 34(10): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2008.10.079This paper proposes a novel fast multi-frame motion estimation algorithm based on H.264. The proposed algorithm can reduce the computational complexity by predic the initial search point prediction of the reference frames and extending the diamond search to multiple reference frames. Experimental results show that the algorithm can decrease the encoding time by 60% while maintaining nearly unchanged PSNR of pictures and bit rate compared to the fast motion estimation algorithm named UMHexagonS in H.264 reference software JM9.6.
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Computer Engineering. 2008, 34(10): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2008.10.080Aiming at the strong influence of underwater battlefield environment on the power of naval operation, the design scheme of environment virtual simulation system based on virtual reality and visualization techniques is researched and presented. The system simulation models are established. Based on the mainly characteristics of ocean environmental parameters and underwater acoustic models, the synthetic simulation and visualizing analysis system of ocean geography, hydrology and underwater acoustic environment are established, which give an efficient method for awareness, simulating training and operational application of underwater battlefield environment.
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Computer Engineering. 2008, 34(10): 224-225. https://doi.org/10.3969/j.issn.1000-3428.2008.10.081In order to transmit real-time video in mining Intranet reliably, a multi-source application level multicast system is proposed by deploying stream service nodes in current network. A delay-bounded and degree-bounded routing algorithm is used to manage and optimize the nodes in the multicast tree. The validity of the system is verified by practical performances. Compared to the average frame loss rates of the traditional C/S video-monitoring system, those of the proposed multicast system decreases above 50%.
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Computer Engineering. 2008, 34(10): 226-228. https://doi.org/10.3969/j.issn.1000-3428.2008.10.082The paper presents the design and implementation of cultural heritage video retrieval system. The system structure with MVC pattern and the function of each module are described. Aiming at the narrow network bandwidth and mass data transferring, a new Content-based Video Retrieval(CBVR) method using video fingerprints is proposed. In the algorithm, the average value of RGB color channels is calculated as the characteristics of video sequences, and the corresponding video retrieval algorithm is developed. Experimental results show that the algorithm gets better performance than original one, the nicety has been improved by 33.33%.
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Computer Engineering. 2008, 34(10): 229-231. https://doi.org/10.3969/j.issn.1000-3428.2008.10.083By analyzing the difficulties of system realization and combining high performance broadband information network(3TNet) architecture and IPTV service model, this paper proposes a design scheme of IPTV multi-display monitor system to solve the problem of monitoring the quality in IPTV environment. This method can serve for IPTV quality monitoring, and facilitate the IPTV provider. The scheme has been used in 3TNet network TV and obtains promising effectiveness.
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Computer Engineering. 2008, 34(10): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2008.10.084To improve the quality and effect of video sequences with noise, this paper proposes a switching 3-D median filter algorithm combining noise detection and 3-D median filter. 3-D median filter is applied to noise points by judging each pixel in noisy video sequences. The noise points are judged for the second time applying distorted 3-D median filter until all the noise points are eliminated. The experimental results prove that the algorithm can achieve good filter effect on “snow flower” noise. When 25 percent “snow flower” noise is added, switching 3-D median filter algorithm performs 10 dB better than 3-D median filter on average.
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Computer Engineering. 2008, 34(10): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2008.10.085When a node of Peer-to-Peer(P2P) media distribution network downloads data from a number of other nodes at the same time, it needs to schedule the downloading tasks rationally in order to complete as many tasks as possible on time. As a solution for this problem, a scheduling schema based on multi-task association is proposed. By taking all requests in a period into account and scheduling them as a whole, the schema can effectively improve service performance of this system. The simulation results show that it can improve the concurrent processing capacity by about 10 percent.
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Computer Engineering. 2008, 34(10): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2008.10.086Ji et al improve PayWord protocol and propose micro-payment protocol(NMP), which has better features on security and fairness. Based on Self-Renewal Hash Chain scheme(SRHC), an improved micro-payment scheme is proposed. The analysis shows that the scheme can solve the problems in NMP, and has better features on security, efficiency and fairness. In the payment phase, the storage and communication load of the scheme is 80 B longer than that of NMP, but the PayWords computation efficiency of the former is 125 times as high as that of the latter when the transactions of 10 000 electron shares are accomplished.
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Computer Engineering. 2008, 34(10): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2008.10.087After introducing processor AT91RM9200 and embedded Linux operating system, this paper designs a multimedia network controller. The design and implementation of the controller is expatiated in elevator car control system. Hardware design according to the requirements of the system is given. Then some critical and difficult technologies like operating system transportation, hardware driver are particularly discussed, and reasonable methods to resolve the difficulties are presented. The future applications of this controller are given.
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Computer Engineering. 2008, 34(10): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2008.10.088Ash deposition on heat transfer surfaces is a primary cause of reducing operating efficiency and safety in coal-fired boilers. Among all available means for managing ash deposition, sootblowing is the primary controllable factor in practice. A new time series clustering based method is set forth for predicting when to sootblow. In this method, sootblowing patterns, which represent the characteristics of sootblowing, are picked out by time series clustering from historical data that are preprocessed, then a model is built to predict when to sootblow. The performance of this method on a 900 MW supercritical boiler is good.
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Computer Engineering. 2008, 34(10): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2008.10.089The different implements of the IEEE1588 are very important to the precise time synchronization. This paper expounds the structure of the PTP engine module, realizes the state machine of the PTP, the best master clock algorithm and the local time synchronization algorithm, and optimizes the process of receiving and sending the message. The experiment shows that the synchronization accuracy is in the range of 10 microsecond by using the implementing method in the paper and satisfies the need of the measurement and control field.
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Computer Engineering. 2008, 34(10): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2008.10.090This paper presents a hardware design of a kind of video monitoring system based on Wireless Local-Area Network(WLAN) for domestic security. A dual-core processor OMAP5910 is selected as a control chip in embedded video network server, with video signal captured by CMOS image sensor OV9650 and message transmitted by wireless network module TNET1100B. This scheme can also be referenced by security video monitoring systems in other fields.
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Computer Engineering. 2008, 34(10): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2008.10.091This paper studies the new version of ISO 9000 approved in 2000 and analyzes the relationship of operation process quality and project quality in the organizations in which many business processes are organized into projects. Based on the characteristics of product development project, the two-step clipping method is present to realize the project quality management from ISO standards to a special project. By using object-oriented method, the quality management models for product development project are built, including organization model, function model, process model and information model. The models harmonize the relations between project processes and operation processes and achieve the enterprise-level quality management for product development project through organization, project management office and project three-tier quality management. Based on the given models, the quality management information system is developed on J2EE platform..
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Computer Engineering. 2008, 34(10): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2008.10.092Cluster system is a widely used architecture in modern high performance computing. Cluster simulator is an important tool to learn cluster operation. This paper proposes the Virtual Cluster System(VCS) based on Godson2E multi-processor hardware platform, to simulate cluster environment by running many independent operating systems in shared memory multi-processor, and simulate network communication by memory operations.
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Computer Engineering. 2008, 34(10): 259-260. https://doi.org/10.3969/j.issn.1000-3428.2008.10.093The communication cost between the processing nodes in parallel processor is the performance bottleneck of the processor. This paper presents a parallel processing system using TMS320C641X DSPs as core processor based on multi interconnection networks of PCI bus, McBSP and the packets switching network. Data of input, output and control separately flow on different networks suitable for them. The transfer efficiency is improved. This design implements the combination of high performance DSPs and high performance interconnection system.
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Computer Engineering. 2008, 34(10): 261-263. https://doi.org/10.3969/j.issn.1000-3428.2008.10.094Manufacturing grid Quality of Service(QoS) management is different from QoS management of Grid’s application in other fields and the quality management of manufacture field. Based on the ideas of grid and the actual situation of manufacture, this paper extends the quality control that impenetrates the whole PLM, and constructs the QoS management system of manufacturing grid. It analyzes the profound relation between manufacturing grid QoS management and other important function module.
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Computer Engineering. 2008, 34(10): 264-265. https://doi.org/10.3969/j.issn.1000-3428.2008.10.095The meteorological parameters really correspond with certain geographic location. Based on Scalable Vector Graphics(SVG) and Web Geographical Information System(GIS) technology, the provincial information system for meteorological parameters combined the historical information in meteorological database and the result of exploration with geographic information platform. With both Browser/Server(B/S) and Client/Server(C/S) model, user can get the geographic distribution of meteorological parameters for analyzing effectively.
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Computer Engineering. 2008, 34(10): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2008.10.096This paper builds a simulation model for population growth based on GIS, multi-agent system and stochastic process. A conception of efficiency function of resource is brought forward to represent the effectiveness of a resource which is maintained by GIS. It implements the multi-agent system, and some experimental analysis is done. This model can be adapted to more comprehensive research than population growth, and owing to its good performance in modularity and scalability, this platform has a potential of being expanded to match other urban planning research.
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Computer Engineering. 2008, 34(10): 269-270. https://doi.org/10.3969/j.issn.1000-3428.2008.10.097Radiology Treatment Planning System(RTPS) is an important component of radiology treatment solution, and its applied safety will directly affect implementation of the entirely solution. This paper introduces Role-Based Access Control(RBAC) model and describes the application rationality and validity of RBAC in RTPS based on development practices of RTPS and clinic condition of radiology treatment. The relation of access control module based on RBAC model and RTPS is analyzed. The system structure of access control module, database table structure design, and implementation in VC6.0 are given.
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Computer Engineering. 2008, 34(10): 271-273. https://doi.org/10.3969/j.issn.1000-3428.2008.10.098The surveillance method of data collecting in current meteorological telecommunication information system is too simplex to satisfy the users’ requirement. In this paper, integration meteorological data real-time operation platform utilizes the technologies of classified storage, dynamic projection localization, multi-request and asynchronous access. According to the circumstance and the characteristic of meteorological data, this platform realizes the design which is based on Web GIS.
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Computer Engineering. 2008, 34(10): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2008.10.099This paper presents a quick ray tracing algorithm of surfaces of revolution based on hybrid bounding volume. According to the local monotonic of the curve, the generatrix of the surfaces is segmented into monotonic intervals to connect the monotonic intervals to get a binary tree. Then each monotonic interval is subdivided again in the course of ray tracing, and subsets of the intervals are the leaves of the binary tree. The bounding shell is constructed for every subset based on the method of the hybrid bounding shell. Experiments show that the algorithm constructing the scenes of surfaces of revolution has a high approximation accuracy with perfect rendering quality. Compared with Kajiya’s classical work, the average rate of rendering is improved by 40%.
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Computer Engineering. 2008, 34(10): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2008.10.100This paper presents a cartoon facial animation system based on facial feature analysis. While a real digital facial photo and some texts are input, a series of cartoon facial animation with entertainment is shown. The method based on facial feature analysis is adopted here. The cartoon facial animation is synthesized based on the caricature using text driven method. The system is transplanted to the mobile platform and the cartoon facial animation is played in the phone. Experiments show it performs well on the PDA.
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Computer Engineering. 2008, 34(10): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2008.10.101To acquire accurate speech information in cochlear implant under noise enviroments, a speech enhancement in cochlear implant based on human auditory masking properties is proposed. Bark wavelet transform is used to realize speech in electronic cochlear implant and to realize speech enhancement combined with human ear’s auditory system. Subtract parameter is got based on the masking properties of human auditory and self-adaptive.The result shows that the SNR output can be improved by 30 dB even if the SNR input is low and can reduce the residual noise and backgrand noise more effectively. The enhanced speech is more clear and intelligible.
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Computer Engineering. 2008, 34(10): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2008.10.102This paper presents a solution to share the distributed heterogeneous data based on the technologies of Metadata and Web services. To resolve the problem, two main methods are adopted: on the one hand, the Metadata is utilized to describe and manage the distributed heterogeneous data centralizedly; on the other hand, the technology of Web services is used to parse the data and make them accessible on Internet. The solution has been applied to the Platform of Shanghai Resource and Environment Data Sharing successfully, which improve the efficiency of the data using.
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