20 April 2009, Volume 35 Issue 8
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Computer Engineering. 2009, 35(8): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.08.001The real-time event scheduling method of NS Emulation(NSE) facility is analyzed, and the processing of discrete events by the synchronization of NSE is viewed as a modified queuing system, thus the queuing model of the real-time event scheduling is established. The waiting events at the synchronization time are viewed as a embedding Markov process, so the distribution of the waiting events is obtained, and furthermore the distribution of the waiting events at any time is obtained. By getting the conditional probability distribution of waiting time as to the finished number of service during the waiting period of discrete events and the number of other discrete events that have arrived by the synchronization time before the arrival of this one, the distribution of waiting time of discrete events is obtained.
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Computer Engineering. 2009, 35(8): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.08.002A lightpath-estimation-based differentiator service mechanism is proposed for overlay IP/WDM networks. The existing methods proposed in literatures, which selectively block lower priority traffic using wavelength consumption information, cannot be applied in the circumstance that the IP/MPLS layer is unaware of physical hop counts of lightpaths. The proposal estimates physical hop counts of lightpaths with a lightpath differentiation scheme, estimates the amount of wavelength resources that connections consume, and rejects lower priority connection requests which occupy large amounts of wavelength resources. Simulation results show the mechanism can effectively provide differentiator service for traffic of different priorities.
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Computer Engineering. 2009, 35(8): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2009.08.003This paper proposes a trust model which combines reputation and credential. The model is based on reputation trust management, and according to the correlation of credential and reputation, the model can derive credential trust from the credential adaptively, combine the credential trust and reputation to get the overall trust value. Simulations show that this model can improve the accuracy of the trust value computation significantly, especially under circumstances where the service provider’s interaction history is very few.
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Computer Engineering. 2009, 35(8): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2009.08.004When the resolution of reconstruction image is high, the FDK algorithm of cone-beam CT image reconstruction is time-consuming. To improve the time performance of the FDK algorithm, two parallelization algorithms are analyzed. Claster parallel computing and SSE instruction optimization technology are applied to the FDK algorithm and the algorithm is realized on an 8 nodes cluster. Results show that the reconstruction speed of the image with 2563 resolution is improved about 29 times via this method.
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Computer Engineering. 2009, 35(8): 13-16. https://doi.org/10.3969/j.issn.1000-3428.2009.08.005This paper proposes a new Application Layer Multicast(ALM) algorithm based on the peer performance evaluation, an ALM based on Peer Performance Estimate(PPE) which constructs and maintains the ALM tree. PPE organizes the multicast tree mainly by the peers transmission ability and incorporates other related information. The algorithm makes the high performance peer close to the media source and the low performance one close to the leaf, which improves the efficiency of the multicast tree, and decreases the delay of peer-to-peer, link stress, link stretch and control overhead. Analysis and simulations show that PPE can efficiently improve the performance of ALM on large scale peer conditions.
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Computer Engineering. 2009, 35(8): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2009.08.006Aiming at the problem that TCP performance declines largely in Ad Hoc networks, this paper develops a Load-Adaptive Backoff(LAB) algorithm, which based on monitoring the number of consecutive idle slots. By measuring the number of consecutive idle slots, LAB algorithm is capable of optimizing network throughput through adjusting content windows adaptively. The consecutive idle slots help the nodes who share a common wireless channel converge to a coincident backoff window after monitoring the number of consecutive idle slots. Simulation results demonstrate that this algorithm has high performance in terms of network throughput and fairness than BEB and other backoff algorithms.
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Computer Engineering. 2009, 35(8): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2009.08.007
After describing the basic demands of computer forensics, this paper puts forward a system of proving the reliability of computer forensics. Thought of digital forensics and its system is studied. With the definitions and illations of the forensic methods and gained data, it investigates a formalized method of proving the validity of computer forensics. The method is put forward to proving the reliability of a computer forensics as an example.
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Computer Engineering. 2009, 35(8): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2009.08.008After a thorough analysis and study of process industry system, an object-oriented modeling method for the directed acyclic graph of process industry systems is proposed. Techniques for determining key factors of process industry system models by object-oriented techniques are elaborated. Mechanisms for the modeling of the directed acyclic graph of process industry systems are defined and described. Characteristics of this process industry system model are discussed and expanded. Cases for diagnosing abnormal situations of process industry systems are explored to illustrate the validity of this system model in solving problems.
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Computer Engineering. 2009, 35(8): 26-27. https://doi.org/10.3969/j.issn.1000-3428.2009.08.009Stress is an important prosodic feature for stress-timed language such as English. This paper presents a new approach using auditory model-based Pitch Synchronous Peak Amplitude(PSPA) feature, which incorporates frequency and intensity information in English lexical stress detection. PSPA feature, along with traditional features and their combinations to English lexical stress detection are evaluated with ISLE database. Experimental results show that the combination of new feature and traditional features demonstrates a 1.5% error rate reduction.
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Computer Engineering. 2009, 35(8): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2009.08.010A bidding strategy is proposed for resource allocation demand of mobile agent system. In this strategy, both Agent time slice demand and execution deadline demand are considered. The CPU slice combinational auction model is defined. And a method is designed to process the agent bidding information. A constrained zero intelligent bidding algorithm and New Zero-Intelligence-Plus for sealed combinatorial Auction(NZIPca) bidding algorithm for this mechanism are designed. Simulation results show that NZIPca stratage has better winning performance.
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Computer Engineering. 2009, 35(8): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2009.08.011Aiming at the issue of multiple input message under restricted conditions, this paper provides multi-message-queue concurrent model and weight load forecast model, as well as a two-phase strategy, which makes the quick dispatching and dynamic load balance come true. It proves its advantages by simulation, and designs an interactive message management system, which meets requirements of interactive message service.
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Computer Engineering. 2009, 35(8): 34-37. https://doi.org/10.3969/j.issn.1000-3428.2009.08.012Aiming at the phenomena such as precocity and stagnation of ant colony algorithm, the mechanism of immunity algorithm is put into ant colony algorithm. This paper presents a new hybrid algorithm absorbed the adaptive feedback mechanism and fast convergence merits of ant colony algorithm and simple operation operators and keeping diversity of groups without degenerating merits of immunity algorithm. The new hybrid algorithm is compared with basic ant colony algorithm and immunity algorithm from the aspects of solution quality and algorithm efficiency. Results show that the new hybrid algorithm performance is improved markedly. It also provides a new idea for solving other combinational optimization problems.
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Computer Engineering. 2009, 35(8): 38-39. https://doi.org/10.3969/j.issn.1000-3428.2009.08.013A kind of method to optimize performance of ORM tools is introduced. By analyzing the fields of objects loaded and used exactly in each HTTP request, the ORM tools only load the required fields to improve the performance of the persistence layer. The improved ORM tools are applied to XPETSTORE which is an E-commerce sample application. Test results indicate that the HTTP response time is reduced by an average of 8%.
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Computer Engineering. 2009, 35(8): 40-43. https://doi.org/10.3969/j.issn.1000-3428.2009.08.014The immune information evolutionary mechanism of artificial immune system is used into Particle Swarm Optimization(PSO) algorithm, a new clustering algorithm based on C-means and improved PSO is presented, it can avoid “early ripe” of PSO and traditional clustering algorithm. New algorithm chooses the suitable inertia weight for every swarm through the linearly decreasing weight policy, and uses the immune evolutionary principle to improve the process of PSO. According to the experiential rule of classical clustering theory and swarm performance cost function, the new swarm is generated above the best particle and then find the best k. Simulation experiments show that this method outperforms the classical clustering algorithm in convergence ability and it has the advantages of high accuracy of clustering and good clustering ability.
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Computer Engineering. 2009, 35(8): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2009.08.015The realization of object dictionary is very important to CANopen proposal. It can be realized using array or linked list. The way of array requires large amounts of memory space and it is hard to update object dictionary dynamically. The way of linked list is so low in search efficiency for a large quantity of data. Because of the characteristic of structure, Hash table can overcome these disadvantages. In this paper, object dictionary is designed using Hash table, which can update dynamically and search efficiently. In addition, it is more efficient to make use of memory space.
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Computer Engineering. 2009, 35(8): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2009.08.016This paper proposes a new mining approach of user’s preferred browsing paths through Web logs based on “three matrices” models. This approach establishes session matrix and trace matrix by taking browsing interest as the fundamental element based on cell storage structure (storage matrix), and carries on page clustering in the session matrix through using angle cosine in vector space between two pages, which is called the similar user’s page distance formula. The similar user’s relative pages set can be got. The similar user’s browsing preferred paths by using path choice-preference in similar user’s trace matrix are mined. Experiments prove that this method is reasonable effective and can obtain a more accurate user’s preferred browsing paths.
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Computer Engineering. 2009, 35(8): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2009.08.017Through researches and analyses on Multi-Relational Decision Tree Learning(MRDTL) algorithm, MRDTL-2, for the problems of low running efficiency and poor effect in dealing with missing attribute values of it, this paper introduces an Improved Multi-Relational Data Mining (IMRDTL) algorithm. IMRDTL algorithm makes use of the tuple ID propagation for speeding up the efficiency of MRDTL-2 algorithm, meanwhile, generalized naive Bayes classifier is used to fill in missing attribute values, so the algorithm can provide a better accuracy.
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Computer Engineering. 2009, 35(8): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2009.08.018Aiming at the low efficiency problem of the construction of decision tree in large-scale training units, this paper presents an improved construction method for decision tree. This method uses FP_Tree algorithm to save more memory than Apriori algorithm. It takes the place of split algorithm of the training units in classical algorithm by the path of FP_Tree, and gets the same decision tree model as the original algorithm. Test results show that the improved method has good property.
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Computer Engineering. 2009, 35(8): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2009.08.019The evaluation of associated rules is an important question in the process of data mining. Good evaluating methods are favor of removing feigned and unvalued associated rules. Traditional evaluating methods are support and confidence which are both based on probabilistic computing. The limitations of those two methods are analyzed. It is indicated that lacking logic basis is the important question that the methods of support and confidence are both in face of. With the theory of general relativity, a new method of abstracting associating rules is presented, which is based on formulas of general logics. Experimental results show that the method can improve the quality of abstracting process effectively.
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Computer Engineering. 2009, 35(8): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2009.08.020Architecture Analysis and Design Language(AADL) is a modeling language based on Model Driven Architecture(MDA). Aiming at how to automatically generate executive framework code of AADL models, this paper presents conversion rules from AADL model elements to C language elements and designs a tool of automatic code generator “Generator” that converts AADL models into C language framework code. The example proves the effectiveness of converting AADL model to C code.
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Computer Engineering. 2009, 35(8): 62-64. https://doi.org/10.3969/j.issn.1000-3428.2009.08.021To solve the contradiction between traditional programming model and parallel structure, aiming at the characters of multimedia and network application program, a parallel programming model based on multi-core processor is proposed, which uses parallel program description modes for nodes to make the parallel compilers run in mult-cores. Experimental results show this novel model can promote the efficiency of program running effectively.
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Computer Engineering. 2009, 35(8): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2009.08.022Schema mapping is applied in many important areas like database integration in recent years. With schema mapper, a semi-automatic tool is demonstrated for schema integration that combines a novel visual interface with an algorithm-based recommendation engine to cope with such a challenging problem. Formative evaluation and user’s study suggest that schema mapper may be usefully employed for performing schema mapping based on XML efficiently and quickly.
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Computer Engineering. 2009, 35(8): 68-69. https://doi.org/10.3969/j.issn.1000-3428.2009.08.023This paper proposes a new clustering algorithm which analyzes the gray association value of inspected attribute, transforms them into attribute weight, and applies them in distance calculation of connected components clustering. The algorithm is applied into clustering analysis of categorized problems about cell status in industry production of aluminum electrolysis. Experimental results proves that this algorithm overcomes the defects of the euclidean distance on some extent, reflects the impact of attribute, and improves the quality and performance of clustering.
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Computer Engineering. 2009, 35(8): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2009.08.024This paper presents a novel regression test method to test object oriented software based on UML design. It obtains classes and methods which must be retested after software’s modification, and analyzes UML sequence diagrams with respect to these classes, then identifies the message guards on sequence diagrams and creates dynamic slices about each conditional predicates, and generates test data for this slice.
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Computer Engineering. 2009, 35(8): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2009.08.025In the system of Transactional Memory(TM), it is necessary to optimize the OS supporting to transaction at present. This paper analyzes the current architecture and provides a good support to transaction-level context-switch by modifying the related modules on OS based on the Log- based Transactional Memory(logTM), which can make the transaction-level thread being executed with a great efficiency under the control of OS.
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Computer Engineering. 2009, 35(8): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2009.08.026This paper presents a data allocation strategy used in High Performance Data Processing Middleware(HPDPM) system to improve system parallelism, reduce communication costs, make the inquiry load price to be smallest, and enhance system response ability. Based on the fundamental thought and working principle of this strategy, a framework and the primary modules of the middleware system are described. This middleware system is applied to a national large engineering project.
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Computer Engineering. 2009, 35(8): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2009.08.027It is difficult to deal with heterogeneous database replication with little overhead in large distributed applications. After analyzing original approach, this paper intends to capture database changes SQL in data access interface of applications. All database changes can be easily captured with new method and transaction property of database is guaranteed. Practical application verifies the feasibility of the approach .
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Computer Engineering. 2009, 35(8): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2009.08.028A new method of temporally sequence management in grid simulation is proposed in this paper. The method combines federates’ services schedule model in need of grid simulation with the interaction among federates, and classifies the events of the simulation. Through building the mutual local event trigger metric and temporally sequence metric, it can calculate easily the start time of every event with the Mutli-AWS algorithm. The experimental result shows that the new method can insure the temporally sequence among federates’ events, and solve effectively the problem of federates’ service schedule model in need.
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Computer Engineering. 2009, 35(8): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2009.08.029Replacement algorithm optimization is the core of cache model research. Independent Reference Model(IRM) and Markov Reference Model(MRM) are analyzed and compared in this paper. Based on the measurement of relative popularity and Byte cost, optimal Web cache model and corresponding algorithm are presented that satisfy different performance metrics. Simulations and analysis show that optimal algorithm outperforms the existed Web cache replacement algorithms in corresponding performance.
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Computer Engineering. 2009, 35(8): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2009.08.030Aiming at the problems existed in Operating System(OS) process monitoring, a new full-virtualization-based process monitoring method is proposed. It uses full virtualization technology to detect and isolate all the harmful behaviors of untrusted processes in OS. Experimental results show this method has better performances of pellucidity and portability, which can prevent against multiple attacks and incur only a small amount of performance overhead.
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Computer Engineering. 2009, 35(8): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.08.031P2P storage system is organized in a peer-to-peer way. Service-oriented architecture is an idea to provide effective storage resources management and service on demand. The P2P storage system model presented is constructed on structured overlay network using layer mechanism. Storage resources on heterogeneous nodes are encapsulated in service blocks. Individual storage view can be customized from users’ point by dynamic choice and combination of services. In addition, deployment of layers in peer is also described. This model is decentralized controlled and has good scalability.
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Computer Engineering. 2009, 35(8): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2009.08.032An extensible automatic parallel compiler system called Agassiz is introduced, and its design structure and key characters are researched. In this system, serial programs can transform to parallel programs, which provides a better research platform that facilitates the development of compiler optimization techniques. Throughout the object-oriented design and implementation, Agassiz can integrate various parallel optimization techniques. Experimental results show this system has better performance of extension.
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Computer Engineering. 2009, 35(8): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2009.08.033Aiming at the inefficiency problem of existing reduction algorithms which use dependency to evaluate the quality of an attribute, and can not deal with inconsistency system, this paper proposes an algorithm based on Error Rate(ER) whose complexity is O(|A|2|U|) to compute the equivalent classes. This algorithm uses the include relationship of equivalent classes and the property that positive region increases with the amount of attributes. It introduces ER as the measure of an attribute. Experimental results with UCI data show that this algorithm is efficient.
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Computer Engineering. 2009, 35(8): 100-103. https://doi.org/10.3969/j.issn.1000-3428.2009.08.034Based on previous works, this paper describes the design of object-oriented nonlinear finite element software framework from a different way, for the software framework can be more flexible and perfect. By using the method of separating model analysis method from finite element model, it describes dependence relation of many classes and message processing, establishes the structure of nonlinear finite element software framework, improves the code modularity, reusability and expansibility, and solves important difficult problem of long-standing in nonlinear finite element development.
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Computer Engineering. 2009, 35(8): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2009.08.035Aiming at the problems existed in present Knowledge Management System(KMS), a novel enterprise knowledge management system based on Web2.0 is proposed, and its structure design method is introduced. The effective enterprise knowledge management is conducted after the characters of KM and the function of modules in this system are analyzed. Experimental results show this system has better performances of extension and the values of application.
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Computer Engineering. 2009, 35(8): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2009.08.036There are some disadvantages, consuming a large amount of memories, matching with low efficiency, to query following-sibling nodes in XML document tree model. This paper provides an algorithm based on XML data stream and stack for querying following-sibling. The algorithm uses Simple API for XML(SAX) parser and structural join, matches and outputs all following-sibling nodes of the given nodes. Results show that the algorithm has the advantage of wide applicability, low system resource occupancy and high efficiency matching.
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Computer Engineering. 2009, 35(8): 110-111. https://doi.org/10.3969/j.issn.1000-3428.2009.08.037This paper analyses the deficiency of current grid monitor information service, proposes Globus oriented information archive service which can meet the requirement of applications based on historical state data. It designs two state information retrieve methods based on aggregation framework of MDS, and presents the database structure. Test results show that this service can simplify the development of systems based on grid monitor information.
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Computer Engineering. 2009, 35(8): 112-115. https://doi.org/10.3969/j.issn.1000-3428.2009.08.038Aiming at the problem of traditional grid task scheduling model can not express and process the uncertainty existing in grid environment, because it takes the expected time to compute of a task as an constant, and by means of connective number of set pair analysis, this paper presents a new soft computation method to express and process the synthetic uncertainty of task scheduling for computing grid, namely using a connective number to express the expected time to compute of a task. After presenting the uncertain scheduling model based on connective-number, online uncertain dynamic scheduling algorithm OUD_MCT, and batch uncertain dynamic scheduling algorithm BUD_Surferage are presented for the uncertain dynamic computing grid. Numerical value simulation results illustrate that these algorithms can express the dynamics and uncertainty of expected time to compute of tasks in the computing grid environment. These algorithms are the generalization of traditional grid scheduling algorithms, and with high value in theory and application in the uncertain and dynamic grid environment.
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Computer Engineering. 2009, 35(8): 116-117. https://doi.org/10.3969/j.issn.1000-3428.2009.08.039A recovery method for memory-crash of operating system based on virtual technology is proposed, which solves the problem of reliability of network for remote repairing, and gets over the localization of local recovery. The recovery system using this method can repair the crashed memory in a short time. Experimental results show the loss of performances in the system with this new function of reparing is acceptable.
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Computer Engineering. 2009, 35(8): 118-121. https://doi.org/10.3969/j.issn.1000-3428.2009.08.040Based on analyzing of the Product Lifecycle Management(PLM) and considering the status and trend of future development of modern manufacturing enterprises, the system of product design resources integration system is proposed. Entity, function and flow are modeling separately, collaborative BOM model and integration model are designed for product oriented design, and flow model is structurized for collaborative work during product lifecycle. In order to realize flexibility and sustainable development, AOP design method is used to construct an integrated framework of integration system corresponding to the model.
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Computer Engineering. 2009, 35(8): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2009.08.041Many existing instruction scheduling algorithms are severely hindered or disabled by Java precise exception model and the frequent exception checks, which substantially reduce the amount of instruction level parallelism for compiled Java. This paper presents an algorithm which helps instruction scheduling break the precise exception constraints to achieve significant speedup while ensuring the precise exception constraints. The experimental results prove the usefulness and correctness of the proposed algorithm.
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Computer Engineering. 2009, 35(8): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2009.08.042Speed of memory access is a bottleneck in modern computer system. The out-of-order scheduling of memory access can improve bus utilization of memory effectively. Based on a reordering mechanism called burst scheduling, this paper proposes a priority formula to select the most appropriate burst in each bank to access memory, and an adaptive mechanism is introduced to adjust coefficients of priority formula to adapt different applications. Compared with conventional in-order memory access and burst scheduling, the adaptive mechanism improves bus utilization by 52% and 4.8% respectively, by running SPEC CPU2000 benchmarks and stream.
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Computer Engineering. 2009, 35(8): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2009.08.043Data aggregation is one of the most important techniques to save energy, and most existing algorithms are based on the structure. However, the topology changes continuously in mobile network, which leads to a high cost for maintaining a steady structure. This paper proposes a novel structure-free approach, Energy Efficient Data-Aware Anycast with Random Waiting(EEDAARW) protocol. It employs DAA to improve spatial convergence and RW to improve temporal convergence, so the consumption of energy is balanced and the lifetime of the network is extended. The simulation experiment demonstrates that the lifetime of network is improved by 30% compared with DAARW.
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Computer Engineering. 2009, 35(8): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2009.08.044In order to improve the performance of the presented schemes with low scalability and great complexity, this paper builds a high- performance switching architecture based on parallel storages scheme named Parallel Storage Scheme(PSS). With the flow model techniques, it proves that PSS switch can achieve a throughput of 100% without speedup to the arbitrary admissible traffic that satisfies the Strong Law of Large Number(SLLN). Simple Priority Double Round Robin(SPSDRR) algorithm is presented based on PSS. Simulation results indicate that PSS switch with SPDRR algorithm can obtain high performance.
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Computer Engineering. 2009, 35(8): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2009.08.045Aiming at the Quality of Service(QoS) provision problem in Ad Hoc networks, this paper proposes the on-demand QoS routing algorithm called DQR, which broadcasts limited routing request packets, performs admission control in inter-media node, adaptively reserves and releases resource, uses routing sequence for loop free. Simulation results prove that the proposed algorithm gets a better performance at parameters such as traffic admission ratio, end-to-end delivery ratio, average end-to-end delay.
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Computer Engineering. 2009, 35(8): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2009.08.046This paper analyzes the innate disadvantages of centralized architecture and hierarchical architecture in traditional network management, and presents a new distributed architecture of network management. ADSD algorithm, which is originally used in digital large scale integrated circuit, is applied into management of computer network. To validate the feasibility of distributed fault diagnosis in network, ADSD is compiled into NS. The performance of this algorithm is analyzed, such as the delay of fault diagnoses and the traffic of message. The visual experimental results are presented. The algorithm is improved to reduce the effect in normal network applications. According to the simulation system, it can be concluded that the distributed architecture for network management is feasible.
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Computer Engineering. 2009, 35(8): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2009.08.047Regarding to the issue of power saving of mobile Ad Hoc network, this paper introduces a new kind of routing protocol, Maximum Three Minimum Power-Energy Weight(MTMPEW), which is improved from AODV. The protocol adopts the arithmetic of selecting a transmitting path with power saving. Simulation result shows that, comparing to the classical AODV routing protocol, MTMPEW can better protect power saving node, reduce the power of sending data package, prolong the life time of network and balance the stream of network.
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Computer Engineering. 2009, 35(8): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2009.08.048Using statistics and probability theory, this paper analyzes the connectivity in wireless multi-hop network, and researches the the probability characteristic of communication between any two nodes in the network where nodes are equally distributed. All these researches are tested by simulation experiment, and the results show this theoretical analysis proposed in the paper is correct.
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Computer Engineering. 2009, 35(8): 146-149. https://doi.org/10.3969/j.issn.1000-3428.2009.08.049Aiming at the current structured P2P system’s locality of physical location and accessing resources, this paper takes the current popular structured P2P system Pastry as a foundation, proposes a P2P routing algorithm and gives relevant topology. When routing, the node route to the nodes which are physical adjacent to it. Theory analysis and the experimental results show that the algorithms proposed in this paper have improved the performance of P2P system about routing delays and the length of the path.
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Computer Engineering. 2009, 35(8): 150-151. https://doi.org/10.3969/j.issn.1000-3428.2009.08.050This paper proposes active Virtual Circuit(VC) calculation method for traffic control of Asynchronous Transfer Mode(ATM) network Available Bit Rate(ABR) service, which is a rate-based traffic control scheme. The method based on ERICA algorithm can accurately calculate effective account of active sources according to VC’s active level, and allocate unused bandwidth among all ABR VCs. It shows the rule of Max-Min fair allocation, and ensures the efficiency and fairness of algorithm.
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Computer Engineering. 2009, 35(8): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2009.08.051This paper proposes a new model of information transmission service adapted to heterogeneous communication network of emergency command system. The main functions of the model and some key technologies such as node labeling, routing table generating & maintaining and so on. This model takes into account the characteristics of heterogeneous communication networks and the development trend, uses IP network as the system’s main communication means, and uses other communication means to meet the special communication needs. Application proves that the model improve the capacity of emergency command system, and reduces the complexity of heterogeneous communication.
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Computer Engineering. 2009, 35(8): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2009.08.052This paper improves the decimation attacks method presented by Filiol. By d-decimating the known sequence from two different initial points, it can attack the initial states of two Ld-series LFSR, obtaining 2Ld independent equations with the bits of the initial state of the n-series LFSR, then attacks the other n2Ld bit of the n-series LFSR initial states, consequently recovers the initial states of the n-series LFSR. The computational complexity of improved decimation attack is reduced from C(Ld)+C(nLd) of decimation attacks presented by Filiol to 2C(Ld)+C(n2Ld), where C(m) is the computational complexity of attacking m-series LFSR by correlation attacks or fast correlation attacks.
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Computer Engineering. 2009, 35(8): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2009.08.053The anonymity and dynamic characters of P2P (Peer to Peer) system makes P2P become hotbed with selfish and vicious action. In order to solve the problem of node cheating caused by high dynamic property of P2P, this paper designs a security trust model——BGTR based on the idea of probability model and fuzzy mathematics. The P2P network with BGTR trust model proves higher security and it has better performance to resolve the problems of impostors, malicious collective attacks and free-rides.
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Computer Engineering. 2009, 35(8): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2009.08.054The intrusion detection model based on the population artificial immune is composed of discrete elements among which are no direct interactions. To solve this problem, this paper proposes a model which is based on the immune network. In this model, a dynamic balance system is constituted by the mutual stimulation among different elements, so it can adapt to the continuously updating of the attack. Results show that this model can detect abnormal data packets well, and has a better self adaptability.
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Computer Engineering. 2009, 35(8): 164-165. https://doi.org/10.3969/j.issn.1000-3428.2009.08.055Electronic auctions based on Hash chain have advantages over non Hash-based schemes due to the simplicity and efficiency of Hash chain. Security flaws of a new electronic auction based on hash chain presented by Yang Jiaxi et al are analyzed, and improved scheme which satisfies properties of bid unforgeability, bid undeniability, bid confidentiality, bidder anonymity and collude attack resistance is presented, and the further research idea is given.
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Computer Engineering. 2009, 35(8): 166-168. https://doi.org/10.3969/j.issn.1000-3428.2009.08.056Deep packet inspection is the bottleneck of a network intrusion detection system. This paper analyzes the characteristic of a real intrusion pattern string set, discusses the improvement of a multi-pattern matching algorithm FNP and its implementing optimization on a multi-core and multithreaded platform-Intel IXP2800 Network Processor Unit(NPU). Simulations on Intel IXP2800 NPU show that the improved FNP can achieve 6 Gb/s throughput on a 10 K-size randomly generated pattern sets, and has almost linear speedup.
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Computer Engineering. 2009, 35(8): 169-170. https://doi.org/10.3969/j.issn.1000-3428.2009.08.057For fast computation of scalar multiplication of the elliptic curve over GF(p), with the utilization of the endomorphism whose characteristic polynomial is , -NAF expansion of the integer k is proposed by Ciet in order to speed up the computation of scalar multiplication kP. In this paper, a window technic is applied to the -NAF representation, which gets the -NAF decomposition of k and can obtain better result than -NAF representation with the cost of some quantities of storages. The length and the density of the expansion is accurately estimated.
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Computer Engineering. 2009, 35(8): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2009.08.058Radio Frequency Identification(RFID) as a new automated identification technology has been widely used in people’s daily lives. Privacy and security issues become a central concern. This paper discusses the McEliece Cipher’s secure capability and proposes an RFID security protocol with the improved version. Research and analysis show that the protocol can avoid the denial of service attacks appeared in the symmetric encryption protocols and protect the RFID data practically.
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Computer Engineering. 2009, 35(8): 174-175. https://doi.org/10.3969/j.issn.1000-3428.2009.08.059Taking advantage of the characteristics of bilinear pairings, an identity-based convertible limited verifier signature scheme is proposed. The scheme has the advantages of identity-based cryptosystem，and can resolve the conflict between authenticity and privacy in the digital signature. Security analysis of the proposed scheme shows that it satisfies non-transferability and unforgeability.
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Computer Engineering. 2009, 35(8): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2009.08.060This paper proposes the idea of image “pattern” by investigating all kinds of information hiding and steganalysis algorithms. It divides the patterns into three categories according to human visual effect degree for flipping the center pixel of the pattern, establishes the best embedding pattern storehouse for binary images, statistically analyzes the pattern’s changing characteristics before and after embedding information for binary text images, and proposes a steganalysis algorithm based on pattern analysis for the binary text images. Experiments prove that the algorithm performs well.
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Computer Engineering. 2009, 35(8): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2009.08.061The paper proposes an Ubiquitous Computing Key management Scheme(UCKAS) based on one-way function. UCKAS fulfills the work of generation, distribution and renewing key. From the security aspect, this scheme provides identity authentication and prevents node capture and chosen-ciphertext attack. Furthermore, UCKAS is package-lose tolerance by restoring the loss key. Evaluating its performance comparing to SPINS, UCKAS only needs 80 percent memory space, 40 percent communication overhead, and one third energy overhead by SPINS.
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Computer Engineering. 2009, 35(8): 182-185. https://doi.org/10.3969/j.issn.1000-3428.2009.08.062Aiming at the problems in Online Certificate Status Protocol(OCSP) such as security, the information source of certificate and searching address of OCSP responder, this paper proposes an improved OCSP and a scheme based on the improved OCSP for the cross-certification system. The scheme improves the function of the responder, constructs and validates the certificate path when the status of the certificate is given. The scheme avoids the difficulty of constructing the certificate path due to the different architecture of each trust domain.
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Computer Engineering. 2009, 35(8): 186-188. https://doi.org/10.3969/j.issn.1000-3428.2009.08.063CAPTCHA image is the major technique used by forums to tell computers and humans apart, so that its security is of importance in internet usage. To learn about domestic CAPTCHA images, this paper proposes and implements a model of CAPTCHA image recognition algorithm, and tests almost all image types used in domestic forums. Experiment results indicate that a large part of CAPTCHA images have a recognition rate above 50%, and some with 100%, both of which can hardly block automatic machines. In terms of its practicality, this paper further classifies them into four categories, only to find the optimal category is blank, which means CAPTCHA image technology needs great enhancements.
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Computer Engineering. 2009, 35(8): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2009.08.064Return Routability(RR) procedure is an infrastructureless authentication method which is used in route optimization of mobile IPv6. Some spoofing attacks are found while analyzing vulnerability of the route optimization in mobile IPv6. Experimental result shows that spoofing attacks will make the mobile node fail in using opitimized route, which results in performance degradation and even communication disruption.
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Computer Engineering. 2009, 35(8): 192-194. https://doi.org/10.3969/j.issn.1000-3428.2009.08.065This paper analyzes the theoretical-security model based on the theory of hypothesis testing proposed by Cachin, pointes out both visual and statistical characteristics should be restricted in the process of information-hiding theoretical-security modeling. An innovative security model is created in the way to restrict the variation of both visual and statistical characteristics by confining the value of conditional transferred probability. The security model of information-hiding based on digital images is established through analyzing the specific characteristics of digital maps in two ways. The sufficient and necessary conditions are summarized in conclusion.
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Computer Engineering. 2009, 35(8): 195-197. https://doi.org/10.3969/j.issn.1000-3428.2009.08.066This paper designs an asynchronous pipeline based on the four-phare handshake protocol, realizes the pipeline in the round to satisfy the several rounds operations, and designs the round startup module and asynchronous control signal creating module. In the key expansion, subbytes, mixcolumns module, it uses the multiplexing technology to reduce the need of hardware. It has been fabricated with 0.18 μm CMOS process. Both the asynchronous design and its synchronous counterpart with the same data path are tested. The performance of the asynchronous design outdoes the synchronous circuit, and its throughput is increased by 12.5%.
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Computer Engineering. 2009, 35(8): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2009.08.067An adaptive audio steganography of integer discrete wavelet packet domain based on auditory model is proposed. After the audio carrier is segmented, the candidate segments are decomposed by integer lifting wavelet packet. According to the sub-band masking threshold which is calculated by auditory model and the characteristics of wavelet coefficients, the embedding strength value is set adaptively. Logistic chaotic map is utilized to process the secret information. Experimental results show that besides high capability under the condition of imperceptivity, this method has high security and low error rate.
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Computer Engineering. 2009, 35(8): 201-204. https://doi.org/10.3969/j.issn.1000-3428.2009.08.068Limitation of network security management is analyzed. This paper introduces Policy-Based Management(PBM) approach to network security management, designs a network security management system. The presented system can manage the network security management systems integrately and automately, dramatically reduce the complicity of network security management. is greatly useful to the security management of large-scale network. This paper introduces the design of the system, shows the completing work of key technologys such as the process of cooperation of security productions driven by event-triggered policy and gives an example of the system application.
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Computer Engineering. 2009, 35(8): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2009.08.069This paper presents a new model for recovering the 3-D structure and motion using the image sequences of monocular images. It deductes the relationship between straight line optical flow and the motion of a rigid body, and represents it with second derivative linear equation. A new method is presented to solve the model based on Genetic Algorithm(GA). It needs at least two group of straight-line optical flow in projection plane to recover rotational components of motion. Validity of the algorithm is tested with synthetic sequences.
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Computer Engineering. 2009, 35(8): 208-210. https://doi.org/10.3969/j.issn.1000-3428.2009.08.070Traditional algorithms face efficiency problem because of generating a huge number of candidates or constructing projected database many times. These algorithms will generate unnecessary short patterns or even wrong patterns in the process of mining. To attack these problems, a novel mining algorithm called Motif-divide based Biology sequence Pattern Mining(MBioPM) is presented based on “motif-divide” method. The MBioPM algorithm improves the efficience and avoids the problems mentioned above. Theoretical analysis and experimental results show that MBioPM algorithm improves performance as compared with other algorithm.
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Computer Engineering. 2009, 35(8): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2009.08.071Ovarian cancer protein mass spectrometry data is a high-throughput data and has large numbers of redundant information. The important information is contained in the high-order information. Independent Component Analysis(ICA) can extract useful features from high-order information. This paper makes ICA into the process of feature extraction for ovarian cancer protein mass spectrometry data, and uses class information mechanism to supervise the process of ICA. Simulation results show both ICA and Supervised Independent Component Analysis(SICA) have gained better effect in research of ovarian cancer protein mass spectrometry data, and the recognition rate reaches 98%.
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Computer Engineering. 2009, 35(8): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2009.08.072Aiming at the problem that SEM algorithm always converges to local optimal network, an improved SEM algorithm called DSEM-PACOB algorithm is proposed, which makes use of the better candidate networks and reasonable strategy provided by PACOB algorithm to estimate the missing value of node variables. Meanwhile, it chooses several node variables, which have close correlations with the estimated node variable, to conduct estimation. Experimental results show that, compared with SEM algorithm, this new algorithm makes qualitative improvements on the quality of the final solutions, and has better performance of stability.
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Computer Engineering. 2009, 35(8): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2009.08.073To explain and modify the difference between the second-hand trust evaluation and the first-hand trust evaluation in trust management systems, an expert referral model, disturbing model is proposed. In this model, the inverse problem of DSmT is presented for the solution of the disturbing evaluation. In addition, a Modified Particle Swarm Optimization(MPSO) arithmetic is proposed to solve the inverse problem of DSmT, which proves to accelerate convergence greatly by a performance test with three test functions. Experimental result shows that disturbing model can explain the difference between the second-hand trust evaluation and the first-hand trust evaluation pretty well and the second-hand trust evaluation can be modified to be more accordance with the first-hand trust evaluation.
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Computer Engineering. 2009, 35(8): 220-221. https://doi.org/10.3969/j.issn.1000-3428.2009.08.074Aiming at the problems existed in traditional video tracking algorithm, a novel location and tracking algorithm based on multiple humans occlusion is proposed, which locates the moving object by using an improved projection analysis method, and conducts matching tracking combined with Kalman filter. Simulation experimental results show this algorithm can seperate, locate and track each human location in two different occluded situations.
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Computer Engineering. 2009, 35(8): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2009.08.075This paper proposes a face locating method based on active infrared illumination and Adaboost, which greatly improves performance in robustness and speed. In this system, an active infrared illumination structure is used to get eye candidates, and then face candidates are extracted, followed by a cascaded real Adaboost algorithm to detect all faces. Experimental result shows that it takes no more than 6 ms to locate all faces in one frame for a video stream with a resolution of 640×480.
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Computer Engineering. 2009, 35(8): 225-226. https://doi.org/10.3969/j.issn.1000-3428.2009.08.076The Grey Pseudo Amino Acid Component(Grey-PseAAC) is the combination of the protein amino acid component and the pseudo amino acid component which is derived from GM(2,1). The server is a predictor of protein subcellular location based on the Grey-PseAAC and the augmented covariant discriminant algorithm. The overall success rate is 77.6% by independent dataset applicationsof test. In contrast with the other predictors in the same dataset, the “Grey PortLoc predictor” is more effectively. The study develops applications of the grey theory in bioinformatics.
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Computer Engineering. 2009, 35(8): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2009.08.077A stereo matching algorithm based on dual dynamic programming with row and array is presented, which uses stereo matching model based on an energy-minimization framework, and contains two terms such as the data term and the smoothness term. In process of solving energy-minimization problem, the primitive disparity map using dynamic programming in the row direction is got, based on the results of which a reward is given to the corresponding data term in order to be used by next dynamic programming process, and the final results in the column direction is provided. Experimental results show this algorithm can get a better performance.
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Computer Engineering. 2009, 35(8): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2009.08.078The paper proposes a multi-resolution global terrain rendering method based on projected grids. Using projected grids to subdivide the spherical surface enables fast asymmetric griding of the part which is visible. To improve the efficiency of data loading and updating, the terrain data is hierarchical organized and stored in tiles, and visible region is calculated beforehand. Rendering frame rate is steady because the amount of grids is settled. The experimental results show that the proposed method is ineffective on global 3D terrain real-time rendering, and it can generate visually convincing results with inexpensive computation.
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Computer Engineering. 2009, 35(8): 233-237. https://doi.org/10.3969/j.issn.1000-3428.2009.08.079Graph Cuts Based Active Contours(GCBAC) approach is a combination of the optimization tool of graph cuts and the iterative deformation idea of active contours. An improved algorithm based on Variable Contour Neighborhood(VCN) is proposed to solve the disadvantage that GCBAC repeatedly cuts the contour neighborhood even these parts of the contour have reached the object boundary. The active contour is classified into the boundary-reached part and the boundary-unreached one, and the contour neighborhood is only dilated from the boundary-unreached one, so it sharply decreases the graph-cut time. Experimental results show that the efficiency of the improved algorithm is 2~3 times as high as the original one.on selected data sets and performance analysis are provided.
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Computer Engineering. 2009, 35(8): 239-240. https://doi.org/10.3969/j.issn.1000-3428.2009.08.081This paper offers a Super-Resolution(SR) image restoration algorithm based on Low-Resolution(LR) image fusion. The algorithm fuses a set of LR images to form an image with same resolution as the High-Resolution(HR) image, and interposes a LR image as the initialization guess for the iterative restoration algorithm. Both the above images are used to find the original HR image by the Tikhonov regularization algorithm. Analysis and simulation results confirm that the algorithm has good robustness and faster computation.
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Computer Engineering. 2009, 35(8): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2009.08.082This paper presents a novel thresholding algorithm, and proposes the definition of fuzzy connectedness. The algorithm uses image cut measure as the thresholding principle to distinguish an object from background. The weight matrices used in evaluating the image cut measure are based on the gray levels of an image, instead of the commonly used image pixels. For most images, the complexity of the algorithm can be reduced and the speed of the algorithm can be improved. Simulation results show that the algorithm can bring better segmentation effect compared with most other image thresholding methods.
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Computer Engineering. 2009, 35(8): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2009.08.083Loop-filter can reduce the blocking effect in the codec process. Aiming at the problem that existing algorithms have high computational complexity and costing a lot of time, a new AVS loop-filtering algorithm is presented. This algorithm takes advantage of the correlation between 8×8 bolcks of a picture to obtain boundary strength and modify the related pixels. Experimental results show that the new algorithm can reduce the cost time of loop-filtering and raise the codec speed while maintaining almost the same quality.
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Computer Engineering. 2009, 35(8): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2009.08.084This paper introduces AVS standards, including AVS1-P2 which targets for application of high resolution and high bit rate video coding, and AVS1-P7 which targets for application of low resolution and low bit rate. It describes coding tools of this standard, and compares this standard with a contemporaneous international video coding standard called H.264/AVC. Experimental results show that AVS standard can achieve similar coding performance as H.264 standard with less implement complication.
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Computer Engineering. 2009, 35(8): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2009.08.085Computing amount is the main obstacle of meeting the real time requirement in H.264. Pre-operation occupies 30 percent of the total computing amount. This paper uses FPGA to realize a kind of intra-prediction algorithm, which decides the intra-prediction mode by the grads. This algorithm uses advantages of FPGA logic such as abundant logical element, high speed parallel computing, abundant I/O ports, and adopts circuit architecture with multilevel pipeline and ping-pong operation. The intra-frame prediction module is clear in architecture, and its processing speed is 46.41 times DSP(TMS320C6211). It meets the real time requirement of video image processing.
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Computer Engineering. 2009, 35(8): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2009.08.086The current systems are basically in the structure of one lower machine occupied by one lock, so the waste of the upper and lower machine is serious. Aiming at this situation, this paper proposes a mechanism of “one lower machine with multi-lock”, introduces the schematic circuit of realizing multi-lock compatibility, describes the structure of words together with the multi-lock mapping model facing to entrance guard DCS. An example of one lower machine with four locks is given, result shows that this mechanism is logic precise, safe, reliable, it has great effect on resources economy and can be well extended.
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Computer Engineering. 2009, 35(8): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2009.08.087The system solves many difficult problems in current bridge detecting systems by using wireless communication technology, embedded technology and low power design technology. This paper designs a relay device with C8051 micro-controller and nRF905 wireless chips to increase more terminal nodes and enlarge the scope. It designs a wireless net communication protocol and net debugging interface for the system to make full use of the communication channels, increase the speed of communication data and make it agile and easy to debug and equip. This system can also do static detection, dynamic detection and real time data display for one channel.
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Computer Engineering. 2009, 35(8): 259-262. https://doi.org/10.3969/j.issn.1000-3428.2009.08.088This paper proposes an RFID signal capturing and controlling system for Bus Rapid Transit(BRT) priority. It sets active RFID tag on the BRT vehicle and RFID reader close to the road junctions, and the reader identifies the coming BRT vehicle quickly and accurately. The system performs the BRT signal priority project and controls the signal lamp phase. It analyzes the design of the system and its realization of hardware and software.
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Computer Engineering. 2009, 35(8): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2009.08.089Classical schedulability analysis approaches usually consider the cost of preemption negligible. However, the time consumption is considerable for whole system in the case of high load and too much preemption. This paper discusses the condition of max preemptions with Rate Monotonic(RM) schedule arithmetic, and presents a method to reduce preemption. The task response time is shortened by reducing preemption.
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Computer Engineering. 2009, 35(8): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2009.08.090With the rapid development of information retrieval, cross-media retrieval is becoming a hotpoint, but a few problems haven’t been resolved such as upbuilding effective correlations and calculating similarity between different kinds of media objects. This paper brings up a new method, and uses Ontology to organize different media objects. Experimental results show that this method based on Ontology is effective for cross-media retrieval.
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Computer Engineering. 2009, 35(8): 269-270. https://doi.org/10.3969/j.issn.1000-3428.2009.08.091This paper analyzes the deficiency of traditional simulation methods in virtual sea battlefield, and proposes the idea of realizing the simulation of large-scale virtual sea battlefield based on the digital earth. It extends the research on simulation technology of the virtual sea battlefield from three facets of large-scale ocean surface rendering based on digital earth, embedment of the three-dimensional combat entity and scenario-driven simulation of the virtual sea battlefield environment. The effect of simulation is given.
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Computer Engineering. 2009, 35(8): 271-273. https://doi.org/10.3969/j.issn.1000-3428.2009.08.092With respect to the software and hardware verification requirement of SoC design, a HW/SW co-verification platform is presented. On the platform, HW/SW model is run in different circumstance and information transform is realized through network. The hardware uses HDL to construct HW model, and it implements model of transaction and RTL level. The software uses high level program language accomplished and the simulator based ISS implementation simulation of the hardware. The simulate process executes parallel in different progress and communication through IPC.
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Computer Engineering. 2009, 35(8): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2009.08.093Aiming at the problems that a rapid increase of municipal waste results in an enlargement of collection and transportation fee and pollution in people’s surrounding, a waste collection and transportation management system based on GIS is studied and designed in terms of system structure and database models. An algorithm combining the scanning algorithm and the branching and bounding algorithm is applied for optimizing routines of waste trucks in the system. Experimental results in some area demonstrate that the system is effective and practical for waste management and decreases the fee of waste disposal.
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Computer Engineering. 2009, 35(8): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2009.08.094Aiming at the outstanding problems of traditional supervision manner for steel cylinder with respect to efficiency, real-time, reliability and convenience, Radio Frequency IDentification(RFID) technology is applied to fulfill the identification of steel cylinders, the convey vehicles and the operators, while Wireless Sensor Networks(WSNs) technology is used to achieve the distributed supervision for the environment parameters of the charging and storage procedure. The general structure and the workflow, along with the key hardware functional models design are presented. The application verifies that the system provides a comprehensive solution, which is rapid, real-time, and accurate for steel cylinder supervision information acquisition and processing.
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Computer Engineering. 2009, 35(8): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.08.095Web Services are self-contain, self-describe, and loose-coupling soft components that can be described and published, discovered and transferred via the Internet. Based on the national meteorological wide band, this paper projects and develops a meteorological data service system. It introduces the background of the project and relevant technologies, and describes the design approaches and services implemented. The conclusion is given and some test statistics are showed
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