20 September 2009, Volume 35 Issue 18
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Computer Engineering. 2009, 35(18): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.18.001In a Content Distribution Network(CDN) based on overlay networks with network coding technology, a strategy which is to select the right neighbors to transfer block based upon the degrees of them is proposed. The selection probability of each neighbor is determined by its degree. After this strategy is applied, the utilization of network is improved, and the distribution progress is shortened. Simulation experimental results show that the performance of content distribution is obviously better than the baseline system.
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Computer Engineering. 2009, 35(18): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.18.002The fuzzy mathematics method are combined to establish an improved fuzzy comprehensive assessment method which is based on information entropy. In this model, the coefficients of weight are modified by the information entropy which reflect the avail value of data, and the validity of results are judged by the validate index, then the selection nearness principle which based on closeness degree are given to get the new assessments of which have a ineffective one. A case study is given by using this model and the results compared with the other methods shows that the model established in this paper is strict and reliable, and it is worthy extending.
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Computer Engineering. 2009, 35(18): 7-8. https://doi.org/10.3969/j.issn.1000-3428.2009.18.003Based on ethnic group evolution mechanism, a kind of population structured technology, the Ethnic Group Evolution Algorithm (EGEA) is developed. This paper proposes a kind of ethnic group generation mechanism based on mating strategy. Simulations of numerical optimization show ethnic group generation based on mating strategy improves the searching efficiency of population greatly and makes EGEA become a competitive numerical optimization algorithm.
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Computer Engineering. 2009, 35(18): 9-12. https://doi.org/10.3969/j.issn.1000-3428.2009.18.004Aiming at the problem that various extending overlay simulator can not afford precise modeling and evaluation of the multicast system, this paper proposes Self-Similar Structured Multicast(S3M) whose nodes group supports unitary substitution and multi-tree structure, designs a scheme of structured application layer multicast model simulator. It sets up an appropriate simulation model for S3M based on the sampling scheme of that multicast model. The simulator can substantiate the validity of the S3M protocol in contrast with NICE protocol.
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Computer Engineering. 2009, 35(18): 13-14. https://doi.org/10.3969/j.issn.1000-3428.2009.18.005An index structure——MCSI-tree for spatial data is proposed by combining the division for spatial data objects with bi-tree and R-tree in order to reduce the coverage of the nodes on each level of the tree. In the structure, the topological relations between spatial data objects are recorded and the coverage of the nodes on each level of the tree is as small as possible so that the range query can be done faster. The algorithm for constructing the MCSI-tree, the proof of the algorithm’s correctness and termination, and its time complexity are presented. The algorithm for node insertion is given.
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Computer Engineering. 2009, 35(18): 15-18. https://doi.org/10.3969/j.issn.1000-3428.2009.18.006This paper analyzes the principle and every parameter meaning of open-source code of maximum entropy models, uses the method of the combination of feature frequency and average mutual information to select the features from the candidate feature set, realizes the maximum entropy models for Chinese Word Sense Disambiguation(WSD) by Delphi, and computes models parameters by GIS algorithm. It solves the data sparseness problem by combining the linguistic knowledge. The system for Chinese word sense automatic disambiguation and tagging is implemented. It uses the system to tag word sense of more than 800 multivocal words, and achieves the better correcte rate.
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Computer Engineering. 2009, 35(18): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2009.18.007This paper proposes a new method which uses grid technology to achieve a surface reconstruction of scattered points. It designs for grid parallel loosely coupled hierarchical algorithm. Based on this, study intelligent task decomposition mechanisms based on the Agent technology and the distribution of tasks and schedule strategy based on Condor-G technology. It structures the grid experimental platform for test and analyzes the reconstruction results. Results show that the technology can improve surface reconstruction speed of dense scattered points and reduce cost application.
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Computer Engineering. 2009, 35(18): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2009.18.008The security mechanism of smart card can not dissolve some problems such as tampering the data or code, DoS attacks and re-programming. These problems are mainly caused by destruction of the card’s application circumstance, by confusion or simulation of the operating sequence. By combinating of trusted computing technology and application of smart card, a method to verify the trustiness of the circumstance and actions on the card is present. The implementation for the method is introduced by the development of a kind of chip operating system on smart card, from which the trustworthiness of the financial card is enhanced effectively.
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Computer Engineering. 2009, 35(18): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2009.18.009To solve disorder among information items and lack of information item in the field of information extraction, this paper proposes a Web information extraction algorithm based on Hidden Markov Model(HMM). It parses a Web document into an extended DOM tree, and maps an information item to a state with mapping a path in extended DOM tree about an information item to a vocable. An HMM model is obtained by using induction algorithm. Experiments show that the algorithm has better extraction performance.
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Computer Engineering. 2009, 35(18): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2009.18.010This paper analyses the Internet news reports and finds their characteristics such as redundancy, low centralization of the discussions and the topic drift. An Online Topic Detection(ODT) method for Internet is proposed. It defines the sub-topic to ignore the redundancies reports, presents the double-lays configuration for the low centralization of the discussions, and advances a topic tracking algorithm based on the sliding window. A topic detection system is build according to the method. The system is tested by the real data from the Internet. The results present that this method is better than the single-pass method for ODT. The CDet of the method is under 0.14.
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Computer Engineering. 2009, 35(18): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2009.18.011Aiming at the tracking problem of the rocket target in complex scene, this paper proposes a template matching strategy based on multiple related template matching. This strategy can improve the track accuracy by getting the best template from the previous frame using the mapping transform, which can fit rocket’s size and state automatically. The Kalman filter is used to predict the track of the rocket. Several tracking experiments show the approach is accurate and fast, and it has a better robust performance during the state changing, the size changing and the shelter instance.
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Computer Engineering. 2009, 35(18): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2009.18.012Internet video monitoring is mainly concerned with the textual video information based on the consideration of the efficient problem, although the video content information is very important. In this paper, a regular rule processing regular for the extraction problem based on the ontology theory is formally defined. An ontology model called Ontology Model of Internet Video Domain(IVD-OM) is designed for the video information, and an implementation by using Java program is developed. The proposed approach to a real-world application of a national department is applied. Experimental results show that the proposed approach is effective and can accurately extract the video information from the Web.
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Computer Engineering. 2009, 35(18): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2009.18.013The problem of clock synchronization in the current simulation system and Network Time Protocol(NTP) are introduced in this paper. A software clock synchronization algorithm with high precision, which is realized by importing the mode of “master and slave servers” and the mechanism of time progress and event login in the client on the basis of the NTP is proposed. This algorithm is suitable for the distributed simulation system. The design of a time synchronization system and an experimentation are presented. According to the analysis of experimental data, the algorithm is validated simple and effective.
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Computer Engineering. 2009, 35(18): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2009.18.014Aiming at the problem of efficient operation in Rapid Extended Manufacturing(REM) for armament product, one kind of the workflow management technologies supporting REM based on the instance of armament extended manufacturing is proposed. The workflow modeling, runtime control techniques and the method of implementing workflow management system are presented. The workflow modeling technique based on Petrinet and the workflow engine based on Web are adopted. And the framework of workflow management system in REM is researched. The efficiency of this system is proved in armament production.
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Computer Engineering. 2009, 35(18): 43-44. https://doi.org/10.3969/j.issn.1000-3428.2009.18.015Function Dependencies(FD) and Multi-Valued Dependencies(MVD) are very important contents in relational database theory. It portrays an inner contact among the various attributes of relational database. By introducing the operator representation, this paper discusses FD and MVD, and proves some main properties easily and efficiently. Operator method has practical value for research on relational database.
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Computer Engineering. 2009, 35(18): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2009.18.016Based on the analysis of algorithms have been proposed, this paper proposes the Paths Optimal Ordering Algorithm(POOA) for routing issue of Multi-Protocol Label Switch(MPLS) Traffic Engineering(TE). The algorithm uses a learning machine. It can automatically learn from information proposed by a random environment, calculate the best routing priorities, and determine the best path forward by this. The simulation results indicate that routing reject ratio of the routing algorithm is smaller than that of other algorithms, its calculation speed is faster than that of other algorithms, and it can guarantee Quality of Service(QoS), so it is an efficient and quick routing algorithm.
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Computer Engineering. 2009, 35(18): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2009.18.017In order to solve the existing problems of the complexity of the system, expansion of poor issues and so on, this paper presents an approach based on Model Driven Architecture(MDA) for the development of decision support system, and proposes a framework based on MDA. A case study is provided to exemplify the benefits of the approach. Practice proves that the method effectively shortens the development cycle and improves the efficiency of development.
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Computer Engineering. 2009, 35(18): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2009.18.018Aiming at the problem that the response time of illegal path query is too long, this paper proposes a new indexing method which proceeds pretreatment with DTD schema of XML document. The new index DTD and WAN-Based Indexing(DWBI) adopts a new region-based numbering scheme which can determine the ancestors-descendant relationship between a pair of objects effectively. It uses the DTD to pretreat the querying and queries XML index tree which has been appended DTD information, so that the efficiency of the query is improved.
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Computer Engineering. 2009, 35(18): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2009.18.019Query expansion is an effective method to the queries in information retrieval. After analyzing several methods of query expansion based on mutual information, this paper introduces the vector distance between terms in documents space to the improvement of mutual information and brings forward a query expansion method based on vector distance in documents space. Experimental results show that the method can effectively improve the performance in information retrieval.
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Computer Engineering. 2009, 35(18): 57-58. https://doi.org/10.3969/j.issn.1000-3428.2009.18.020Aiming at the performance problem in traditional centralized composite service execution engines, a novel composite service execution mechanism based on mobile Agent is proposed. The execution process of this composite service engines is introduced. The data transmission among Agents is researched. By analyzing the data of service composite sequences, the data synchronization mode of resident Agent is given. Simulation experimental results show this new mechanism can decrease the network load effectively, and save the transmission consumption.
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Computer Engineering. 2009, 35(18): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2009.18.021Under the parallel computer environment with shared memory, imbalance of processors’ workload and lack of effective pruning methods are two key problems in mining sequential patterns. To solve these problems, dynamic tasks distribution method for achieving balance of workload among processors and the parallel local pruning technology used to improve the mining efficiency by avoiding abundant duplicated projected databases are proposed. A parallel algorithm for mining sequential patterns using these two methods based on Symmetric MultiProcessor(SMP) computer system, Parallel Fast Sequential Pattern mining algorithm(PFSPAN) is proposed in this paper. Both theoretical analyses and practical experiments show that PFSPAN can mine sequential patterns effectively.
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Computer Engineering. 2009, 35(18): 62-65. https://doi.org/10.3969/j.issn.1000-3428.2009.18.022Most traditional Word Sense Disambiguation(WSD) method is just based on contextual information, often results in inaccurate output. A multi-level unsupervised automatic WSD method which works efficiently is promoted. This method utilizes the rich semantic information extracted from online Wikipedia, makes a linear fusion of contextual information, background knowledge and semantic information, uses logistic regression algorithm to learn the weight of each feature, and selects the one with the maximum combined value as correct meaning. Experimental result on SENSEVAL dataset shows an average precision of 85.50%, therefore validates the feasibility and effectiveness of this method.
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Computer Engineering. 2009, 35(18): 65-66. https://doi.org/10.3969/j.issn.1000-3428.2009.18.023According to the character of Web system test, the techniques of script modularization and data driving tes are used to design an automation test framework based on Web, where the foundations are test base framework and data driving test framework. In view of the idea of script modularization, the nested hierarchical management is conducted to the test script, and the division of test data and test script is implemented. Simulation experimental results show this framework has better performance of independence and expandability.
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Computer Engineering. 2009, 35(18): 67-68. https://doi.org/10.3969/j.issn.1000-3428.2009.18.024In order to promote the management efficiency of DiffServ network resource, a Dynamic Resource Management Algorithm(DRMA) is proposed. By measuring the practical network flow, the resource reserved requirements are judged whether are accepted. The bandwidth broker is used to implement the admission control of network data. The network model is simulated by using NS2 tool, and the results show this algorithm can improve the data processing capacity of DiffServ network effectively.
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Computer Engineering. 2009, 35(18): 69-71. https://doi.org/10.3969/j.issn.1000-3428.2009.18.025The application of Inversion of Control(IoC) pattern is introduced to resolve the problem of integration while introducing embedded workflow technology into the application system, so that the coupling of integration and system complexity can be reduced, and the rate of component reuse can also be improved effectively. The problems such as the invasion of system codes, the damage of structure, less flexibility and expansionary led by the tightly coupled system and difficult maintenance can be avoided which result from an inappropriate integration method in the application system. An integration example of Open Source Workflow(OSWorkflow) system and the application system based on Java EE lightweight architecture are given.
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Computer Engineering. 2009, 35(18): 72-74. https://doi.org/10.3969/j.issn.1000-3428.2009.18.026Aiming at the difficulty on software development of parallel auto test system, this paper proposes the layered software architecture of parallel auto test system and the description model for the software architecture. The description model includes five views: requirement function view, frame view, static structure view, dynamic process view and physical implementation view. The software architecture of parallel auto test system can analyze roundly through the description model. And it is benefit for guiding the development of parallel auto test system.
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Computer Engineering. 2009, 35(18): 75-77. https://doi.org/10.3969/j.issn.1000-3428.2009.18.027Previous routing algorithms designed for the linear and parallel service composition are not feasible since there are multiple interactive messages between service components. This paper proposes a feasible selection algorithm of composed service scheme to solve the problem, in which delay is a prior consideration while finding service component, and the interactive message times is regarded as an important metric while choosing a composed service scheme. Simulation result shows that compared with other algorithms, the proposed algorithms achieve better performance.
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Computer Engineering. 2009, 35(18): 78-81. https://doi.org/10.3969/j.issn.1000-3428.2009.18.028By connecting multiple virtual machines in different hosts in different networks, the virtual network is set up. The relevant management scheme is proposed. P2P communication mode is used between one-to-one nodes, while multicast communication mode is used among ont-to-many nodes, which need not other node to transmit the communication, and promote the efficiency of data transmission in virtual network. This scheme is tested and analyzed, and the results show its feasibility.
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Computer Engineering. 2009, 35(18): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2009.18.029Aiming at the environment of large-scale and high dynamic Mobile Ad Hoc Networks(MANET), this paper proposes a Proxy-based Internet Gateway Discovery mechanism(PGDIS). In PGDIS, proxy gateways are elected from mobile nodes automatically, and receive advertisement messages from the Internet gateway periodically. Each mobile node is able to establish the route to the Internet gateway through its nearest proxy gateway. Simulation results show that PGDIS can reduce packet transmission delay while keeping relatively high packet delivery ratio.
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Computer Engineering. 2009, 35(18): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2009.18.030Based on differ-application, this paper proposes a Application Layer Multicast(ALM) model with hierarchical wheel structure. This model can resume itself and transmit data with high speed in a disordered situation. A Differ-application and Flooding based hierarchical Multicast data transmitting Protocol(DFMP) is presented to transfer data by different links according to the applications. It optimizes the topology structure dynamically according to the network status change. Simulation experiment is done under Linux by using P2Psim, and the results show that this model can improve the performance of ALM.
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Computer Engineering. 2009, 35(18): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2009.18.031The duty-cycle protocols exists significant end-to-end delivery latency. In order to solve this problem, a new duty-cycle MAC protocol named PRMAC is proposed. PRMAC can delivery a packet multiple hops in a period based on cross-layer routing information advanced transmission, thus reduce network latency and improve energy efficiency. Simulation result in NS-2 shows that PRMAC can improve end-to-end delivery delay and throughput in traditional duty-cycle protocol without reducing energy efficiency.
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Computer Engineering. 2009, 35(18): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.18.032Aiming at the coverage problem in sensor networks, this paper proposes an analysis approach of resource-constrained information coverage. Considering the energy and bandwidth constraints in sensor networks, it introduces a universal decentralized estimation scheme to make final estimation of quantized discrete messages aggregated by a leader node. Experimental results show that this approach has more realistic and accurate estimation for coverage performance than the one under ideal condition in a practical sensor network.
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Computer Engineering. 2009, 35(18): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2009.18.033Aiming at the problems that the interval number of network interface to open is too much and the network selection time is too long in dynamic activating interval algorithm, a network interface activating interval algorithm based on terminal battery state is proposed, which makes the terminal remaining battery state  as weight of power consumption cost. The network performance function is made as the influence factor of network activation interval. The network flow is managed. Simulation experimental results show this algorithm has less interval number of network interface to open and short network selection time in process of network selection, when the terminal moving speed is less than 1.4 m/s.
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Computer Engineering. 2009, 35(18): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2009.18.034In dynamic networks Random Early Detection(RED) algorithm is sensitive to parameters, as wq etc. A Modified RED(MRED) algorithm is proposed, which discards low-pass filter and introduces a parameter freeze_time. This algorithm is simulated in two scenarios: “large delay and changing load”, “mixture flows of TCP and UDP”. Experimental results show that in dynamic networks MRED algorithm achieves higher throughput and lower end-to-end delay, it can control the instantaneous queue better, and shows good robustness.
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Computer Engineering. 2009, 35(18): 100-101. https://doi.org/10.3969/j.issn.1000-3428.2009.18.035The baseband simulation model of WiMAX PHY-Layer does not take SUI channel into consideration. Aiming at this problem and under the conditions of perfect synchronization, this paper considers the factors effects the system performance synthetically, including SUI channel, the length of Cyclic Prefix(CP), RS+CC encoding, channel estimation, and evaluates them based on Simulink. Simulation results show that by changing the length of CP and using Adaptive Modulation and Coding(AMC), the balance between BER and data rate can be kept.
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Computer Engineering. 2009, 35(18): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2009.18.036Aiming at the problem that different frequency hopping points may have different SNR values in frequency hopping anti-jamming communication, this paper designs a method for SNR accurate estimate according to the self-correlation function value of Barker codes. The channel decoding performance is improved with channel encoding error-correcting by using Low Density Parity-check Codes(LDPC) codes. When some frequency hopping points encounter bad noise, erasure-correct processing is done directly, and the anti-jamming performance of system is improved.
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Computer Engineering. 2009, 35(18): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2009.18.037In P2P media streaming system, the existing peer selection methods only focus on the implementation of the requesting peer, and the function is unitary. In order to resolve these problems, a double-ended cooperation peer selection strategy is proposed, which is between super peer and requesting peer. At the super peer, an algorithm of selecting candidate peers based on routing resemblance is proposed, which is topology conglomeration oriented. At the requesting peer, considering the dynamic and heterogeneity of the system, an algorithm of selecting service peers based on enumeration is proposed, which can guarantee the streaming QoS and meanwhile improve the robust by adding the thought of dynamic redundancy. Simulation results show that the strategy can improve the topology conglomeration, streaming QoS and robust much better.
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Computer Engineering. 2009, 35(18): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2009.18.038Aiming at the problem of the huge bandwidth gap between low capacity requirement of an individual multicast connection and high capacity offered by a wavelength channel in current optical networks, a multicast traffic grooming algorithm based on the multicast traffic grooming model is proposed by grooming new multicast traffic onto the optical multicast trees which have been built, in order to improve network resource utilization efficiency and reduce multicast traffic blocking probability. Simulation results show that the network performance can be improved significantly by the algorithm.
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Computer Engineering. 2009, 35(18): 111-112. https://doi.org/10.3969/j.issn.1000-3428.2009.18.039According to errors of Network Time Protocol(NTP) in the synchronous process, this paper makes a quantitative analysis of the range of these errors through test data and experimental results, and proposes how to select more precise timestamp among timeservers, improves the accurate of network correcting time. Practical measurements result shows that secondary time server are better than primary ones from the perspectives of network delay. This method lays a theoretical foundation for selection of the optimal time server.
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Computer Engineering. 2009, 35(18): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2009.18.040Aiming at the characteristics of space networks and their special requirements for key exchange, this paper proposes a key exchange protocol for space networks. It is based on the Internet Key Exchange(IKE) protocol, and robust to Denial of Service(DoS) attacks by adding circular DH queue and increasing the calculate intensity of Cookie. Some improved methods are presented in defending man-in-middle attack, option attack and reflect attack. Theoretical analysis shows that the protocol has more security, less exchange messages and it adapts to the space networks.
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Computer Engineering. 2009, 35(18): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2009.18.041This paper designs a network connectivity analysis algorithm according to the present techniques and the need of attack graph construction system. By using connectivity analysis, network topology and firewall rule analysis can be performed offline, which determines the connectivity between two hosts. It introduces a conception of Critical Entity Collection(CEC). An effective way of CEC detection is presented on the basis of classic Apriori algorithm. Deep analysis and comparison show that CEC provides effective information for the assessment of the importance of nodes in the network in the process of connectivity analysis.
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Computer Engineering. 2009, 35(18): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2009.18.042A security extension of RTI in Simulation Virtual Private Network(SVPN) environment is put forward against the data link security problems of the traditional distributed simulation system based on High Level Architecture/Run Time Infrastructure(HLA/RTI) technology. The information process in the federation interaction is analyzed, and a concrete security requirement is presented according to the analysis. The implementation of RTI security extension is presented in detail. The logical relation of the software components is provided and the running mechanism of HLA –SVPN simulation application is analyzed.
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Computer Engineering. 2009, 35(18): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2009.18.043This paper analyses how to strengthen the survivability of Wireless Sensor Network(WSN) operating system. Based on TinyOS, it considers improving their survivability in two aspect: external attack and internal fault. A simple and practical intrusion detection and recovery mechanisms is designed, which improves its schedule to support the fault-tolerant real-time schedule strategy. Simulation experiment shows that the improved system enhances its survivability, and has a high energy efficiency.
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Computer Engineering. 2009, 35(18): 125-126. https://doi.org/10.3969/j.issn.1000-3428.2009.18.044Using the way of computing directly, this paper analyzes the computation complexity of the improved Py distinguish attack algorithm proposed by Crowley P. Using the concept of replacing time with space, this paper presents a new method to implement the attack which can reduce the complexity to 1/14 times of that of using the way of computing directly.
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Computer Engineering. 2009, 35(18): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2009.18.045This paper researches and analyzes the undisclosed protocol TDS 8.0 which used in the Microsoft SQL Sever 2000, receives and sends the TDS data packets, analyzes the communication rule of TDS protocol and all types of TDS package, sums up the entire TDS protocol structural framework and gives a detailed description of every TDS segment meaning. Basing on the protocol analysis, this paper researches the system structure and security loopholes of the Microsoft SQL Sever 2000, compiles the loophole test program to validate TDS 8.0 protocol and finds out the secure problems in the TDS 8.0 protocol.
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Computer Engineering. 2009, 35(18): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2009.18.046This paper researches Linux security audit technology and proposes a security audit method based on double spaces security audit. The operating system kernel space system call and user space library function call are merged to enhance the identified ability against the operating system kernel attacks and user’s malicious behaviors, an extended LSM(Linux Security Modules) framework is designed for audit data hook module to improve the audit granularity, security and flexibility of security audit model. In order to improve the real-time efficiency, a typical set method is introduced to compress the normal signature database.
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Computer Engineering. 2009, 35(18): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2009.18.047The minimum critical set is the most important information that network attack graph shows. If all the vulnerabilities in the set are fixed, the whole network will become safe. After researching and analyzing ant algorithm, the paper tries to use ant colony algorithm to resolve the minimum critical set problem in network attack graphs and enhance the algorithm which is put forward by Cincotti. Experiment validates the algorithm.
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Computer Engineering. 2009, 35(18): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2009.18.048Aiming at actual needs of network examination, a secure network examination mechanism is proposed by using cryptological methods synthetically. Encryption, digital signature, digital envelope are used to authenticate the identity of examinee. The network congestion problem caused by downloading the examination paper at the same time for all examinees is solved efficiently and the security is improved when the examinees submit their papers at the same time in the proposed system. A secure management platform for examination is constructed, and the fairness and justice of the examination can be ensured.
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Computer Engineering. 2009, 35(18): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2009.18.049To solve the limitation of combination between traditional key management and routing information, this paper presents an improved scheme of polynomial key pre-distribution based on on-demand routing protocol according to the security requirement. The scheme makes full use of the topology information of routing and the function of the base station, which gathers the important security information and the computing loads, to insure the sensor only stores the polynomial quantum of neighbors. The mechanism can effectively prevent the key from giving away, improves the network secure performance, and save the energy resource.
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Computer Engineering. 2009, 35(18): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2009.18.050Due to the neglect of peer anonymity and information flooding in most reputatioin management mechanisms, this paper proposes a reputation management model of P2P network based on hierarchical Agents named HARMM(Hierarchical-Agents-based Reputation Managerial Model), which uses several public/private key pairs, onion routing and other methods. Analysis and simulation tests prove that the model is capable of guaranteeing peer anonymity and data authenticity, and effectively restrains several typical security attacks.
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Computer Engineering. 2009, 35(18): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2009.18.051By analyzing and improving the artificial immune algorithm based on information entropy and Euclidean distance, a novel Artificial Immune Algorithm based on Intrusion Detection(AIAID) is proposed. The algorithm lies on improving the calculation about similarity and expected breed rate by the principle of Mahalanobis distance, namely introducing the importance and value range of antibody characteristics into correlation computing, and algorithm flow is optimized. A new model for intrusion detection system is designed by using AIAID. Tests indicate that using AIAID in intrusion detection can obviously shorten training time and improve detection efficiency.
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Computer Engineering. 2009, 35(18): 148-150. https://doi.org/10.3969/j.issn.1000-3428.2009.18.052In the current certificate path building schemes of PKI trust model, the following defects exist that the hierarchical model certificate path building has heavy dependence on the security of root node, and the mesh model path building can generate loops. In order to solve the above problems, a new depender graph trust model is proposed which is verified there are many paths between depender graph nodes but no loops, and certificate path building method in the new model is put forward. Experimental results show that the efficiency of the certificate path building of new model is equivalent to that of the hierarchical model, and has similar security comparing to the mesh model.
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Computer Engineering. 2009, 35(18): 151-153. https://doi.org/10.3969/j.issn.1000-3428.2009.18.053This paper proposes a robust digital watermark algorithm based on Discrete Wavelet Transform(DWT) to embed digital watermark into low frequency sub-image. In order to detect low frequency coefficients of DWT which insensitive to visibility, it makes low frequency sub-band median-filted and compared with original low frequency, and embeds the watermark into small changes of the cofficients. The paper compares the proposed algorithm with the watermark algorithm based on the low-pass filtering. Experimental results shows that the algorithm not only ensures the invisibility but also ensures the stranger roubust to compress, median-filter, crop, sharpen, etc.
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Computer Engineering. 2009, 35(18): 154-155. https://doi.org/10.3969/j.issn.1000-3428.2009.18.054s-LFSR is a kind of word-oriented Linear Feedback Shift Register(LFSR) with high efficiency and good cryptographic properties, especially its software implementation is efficient for modern processors. Through the coordinate sequences and base discriminance of primitive s-LFSR, this paper converts the study of counting to the basis of liner space, and through the pairs of relatively prime polynomials on F2 with degree smaller than n, the counting formula of primitive s-LFSR on F4 is obtained.
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Computer Engineering. 2009, 35(18): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2009.18.055The value of recommendation trust is collected by flooding in traditional local trust mode1, but the method has low efficiency and takes up a lot of network resources. This paper presents a trust path search algorithm based on random walk, which is able to improve the search by using the path information in the past. The algorithm is efficient and valuable in network environment which is sensitive to resources occupying because it reduces the number of unnecessary messages and trust circuits effectively.
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Computer Engineering. 2009, 35(18): 159-160. https://doi.org/10.3969/j.issn.1000-3428.2009.18.056This paper introduces the authentication system of Kerberos protocol, and has a detailed analysis of the Kerberos protocol security. On this condition, it imports the scheme of visual cryptography into Kerberos protocol and constructs a new authentication scheme based on visual cryptography. It analyses the safety of Kerberos protocol, and the result shows that the new scheme can resist password attack and replay attack.
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Computer Engineering. 2009, 35(18): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2009.18.057This paper proposes a robust feature extraction algorithm for speech recognition. This algorithm is based on the subband dominant frequency information. It combines the information of subband dominant frequency and the subband power as the new feature. So the information of the positions of subband spectrum peaks is saved. A robust isolated word speech recognition system based on this algorithm is designed. Experiments are conducted to compare the proposed algorithm with traditional feature extraction algorithms under different levels of babble noise and white gauss noise. The results indicate that the recognition accuracy of this system has been improved at some degrees under these noise conditions.
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Computer Engineering. 2009, 35(18): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2009.18.058In order to improve the performance of traditional spectral subtraction in low SNR environment, more accurate noise estimation is needed. This paper proposes a novel spectral subtraction based on noise estimation of spectral entropy. It estimates the noise of each frame according to its spectral entropy, and subtractes it to enhance the frame. Experimental results show that in comparison with other classical methods, the proposed method can obtain better performance in different noisy environment.
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Computer Engineering. 2009, 35(18): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2009.18.059According to the spectrum difference between fabric texture and defect, a new method for defect detection is presented. On the basis of the fabric texture and defect classification, a spectrum image is derived from FFT. The frequency-domain filter is designed to remove normal texture information, based on the image reconstruction, fabric normal texture and defects are isolated by image segmentation. Experimental results show this method is valid and feasibile.
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Computer Engineering. 2009, 35(18): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2009.18.060Based on Support Vector Machine(SVM), the system for the abnormality judgment of X-ray chest file is presented, which can classify the X-ray picture normal and abnormal automatically. In order to improve the efficiency of the SVM, the wavelet transform is adopted in the system to eliminate the redundancy information in image. Two-Dimensional Principal Component Analysis(2DPCA) is used for feature extraction. Experimental results show that the SVM-based method is feasible in X-ray abnormality judgment, and has good classification ability.
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Computer Engineering. 2009, 35(18): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2009.18.061Harmony Search(HS) is a heuristic optimization method. To make HS algorithm be able to apply to the combinatorial optimization problem, a Discrete Harmony Search(DHS) algorithm is proposed. Two improvements of the DHS algorithm are described. The pure DHS algorithm may produce premature and poor results. In order to avoid premature convergence and poor results in DHS, based on the complementary strengths of DHS and Simulated Annealing(SA) algorithm, a hybrid strategy of HS and SA is put forward. Experimental results show that within the framework of the newly designed hybrid algorithm, the NP-hard classic Traveling Salesman Problem(TSP) can be efficiently solved with higher quality.
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Computer Engineering. 2009, 35(18): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2009.18.062Aiming at the location of vehicle license plate in complex circumstance, this paper presents a plate location method which utilizes the features of multiple components’ information of plate character edge color. The plate background color pixels and the character color pixels are extracted respectively, those background color texture pixels which do not neighbor the character color ones are discarded. Because the color of plate character and the color of plate background are influenced by each other, both components of the hue and saturation of character edge color have a relative narrow range. It can reduce the plate search area. It is obviously that this trait is helpful to locate plate accurately and it can ascertain plate color at the same time. The algorithm is carried through binary image mainly, so higher location speed can be easily acquired.
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Computer Engineering. 2009, 35(18): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2009.18.063Traditional research on grid resource schedule attaches importance to the performance, but rarely considers the quality of service. To scale the quality of schedule service, this paper designs an evaluating method for three kinds of user satisfaction, and proposes a Genetic Algorithm(GA) based on user satisfaction for grid resource schedule. The algorithm uses user satisfaction as the gist for gene evolution, and realizes the optimization of grid resource scheduling. Simulation results show that this algorithm can ensure a good schedule performance, and improves the quality of service.
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Computer Engineering. 2009, 35(18): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2009.18.064Inequality maximum entropy method has alleviated data sparseness with flexible modeling capability more successfully than other probabilistic models in text classification tasks, but feature selection algorithm used by the model can not fully bring its advantage. This paper proposes a new feature selection method. It improves the recognition rate in text classification. Experimental result shows that this algorithm works more effectively in selecting representative features and improves the text classification performance a lot.
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Computer Engineering. 2009, 35(18): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2009.18.065Considering characteristics of finding radio interference, the hybrid mechanism which integrate case and rule reasoning is applied in the intelligent diagnose system. The structure of expert system is presented, and the description and search method of the case are introduced. Practical application shows that the accuracy of finding radio interference is improved efficiently by this expert system, and the analysis and verdict ability of the person who deals with finding interference is also improved.
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Computer Engineering. 2009, 35(18): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2009.18.066A real-time banknote sorting method is proposed which uses fuzzy neural networks. In order to satisfy the requirement of real-time, the first-order moments of the pixels values in the local blocks of the image are used as the feature vector of the banknote. The fuzzy neural networks is used to classify the new-old degree of the banknote. The membership function in the network maps the feature space to the target space. The inference layer of the networks analyzes the new-old degree of the banknote. The decision of quality is given by the defuzzy layer. Experimental results show that the method is able to classify the banknote accurately and steadily.
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Upper Approximation Reduction in Inconsistent Target Information System Based on Dominance RelationsComputer Engineering. 2009, 35(18): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2009.18.067This paper introduces the concept of upper approximation reduction in inconsistent target information systems based on dominance relations. Moreover the judgment theorem and discernable matrix are obtained, from which it can effectively provide the approach to this reduction in inconsistent systems based on dominance relations. An example strates the validity of this method. The proposed framework constructs efficient theoretical basis for knowledge discovery in information system based dominance relations.
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Computer Engineering. 2009, 35(18): 194-197. https://doi.org/10.3969/j.issn.1000-3428.2009.18.068Ant Colony System(ACS) can develop excellent performance via self-adaptive behavior. In order to find the internal rules of self- adaptive behavior, this paper introduces parameter-control and sets pheromone’s range, which are applied to the Traveling Salesman Problem(TSP). The ACS internal state is revealed via pheromone’s micro-control and statistical analysis of pheromone’s most values and distribution. Experimental results prove that the improved ACS does well in stability and searching solution.
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Computer Engineering. 2009, 35(18): 198-199. https://doi.org/10.3969/j.issn.1000-3428.2009.18.069To improve the efficiency and effectiveness traditional algorithms which still have some shortcomings, this paper combines the advantages of immune clonal algorithm with simulated annealing, brings forward a routing algorithm based on Immune Clonal Annealing Algorithm(ICAA). The simulation results show that this algorithm achieves resource load balancing, and it overcomes the shortcomings of genetic algorithm, and can be applied to the optimization of task schedule successfully. Experimental result shows that it is concluded that ICAA is exploited to achieve the goal of improving the routing performance, and is superior to other algorithm.
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Computer Engineering. 2009, 35(18): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2009.18.070This paper presents a vision based feedback system framework of position and orientation measurement for parallel robot. It is composed of image acquisition, camera calibration, position and orientation measurement, and parameter feedback. Single camera is used for image acquisition. A kind of 2-DOF parallel robot is used as control object, and Haar-like feature detection is presented as a method of rough object tracking. In order to acquire the real parameters based on invariants of trapezia, the special feature points on the object are determined. An inverse-kinematics of robot is used to get the control signals of every motor. And the feasibility of the system is proved by simulation experiments.
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Computer Engineering. 2009, 35(18): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2009.18.071Aiming at the problem of worse real-time in ordinary rendering fur linght effect method, a Lengyel fur real-time rendering method based on Polynomial Texture Maps(PTM) is proposed, which merges PTM into Lengyel rendering fur method. In period of pretreatment, the fur model is sampled, and the polynomial texture coefficients is calculated, use which, the light information is obtained. The color value is identified by using this information. The fur network layer is rendered from inner part to outer part. Experimental results show this method can meet the real-time rendering requirement of middle-scale objects.
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Computer Engineering. 2009, 35(18): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2009.18.072In order to promote the texture synthesis speed, a texture synthesis accelerated algorithm based on multi-resolution is proposed. By accelerating the speed of searching optimization image blocks, the speed of whole algorithm is improved. On the premise that the image synthesis quality is not affected, it can promote the synthesis efficiency. Experimental results show this algorithm can set up plant organ with high fidelity, when used in virtual plant visualization.
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Computer Engineering. 2009, 35(18): 209-211. https://doi.org/10.3969/j.issn.1000-3428.2009.18.073In order to enhance the real-time of polarization imaging detection, a novel calibration method is proposed, on basis of analyzing the non-uniform polarization direction and responsibility. The imaging method with three-lens is used to resolve the polarization information of calibrated image, which implements the calibration of polarization imaging detection system. Simulation experimental results show this method can promote the visualization effect of images.
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Computer Engineering. 2009, 35(18): 212-213. https://doi.org/10.3969/j.issn.1000-3428.2009.18.074A Canny operator edge detection algorithm based on Bidimensional Empirical Mode Decomposition(BEMD) is proposed, which divides the images into Intrinsic Mode Function(IMF) by using BEMD. The edge detection is conducted to components with Canny operator. The image edge is rebuilt layer by layer selectively. It is tested on gray image sets. Experimental results show this algorithm can obtain better detection performance compared with traditional ones.
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Computer Engineering. 2009, 35(18): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2009.18.075Aiming at the complicated scene of volleyball game, this paper introduces a volleyball trajectory tracking method. By making use of volleyball’s parabolic motion character and its moving distribution features in 2D scene, it gains the volleyball candidate objects according to the natural attributes of volleyballs. By showing the position of volleyball candidate objects in X distribution images axes and Y axes distribution images, it sets up the functions of volleyball trajectory to rectify and assist volleyball tracking. Experimental results show that exact rate of volleyball trajectory detection of this method is 92.25%.
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Computer Engineering. 2009, 35(18): 217-218. https://doi.org/10.3969/j.issn.1000-3428.2009.18.076Aiming at the instability problem of the object detection time efficiency of binary image in video sequence, this paper proposes a fast object detection method. The main steps of this method include dilating layer by layer, filling holes, eroding layer by layer and detecting objects. Theory analysis and experimental results confirm high time efficiency, time stability and detection quality of this method, and its worst time efficiency is approximately equal to 3×3 structuring element’s morphological closing operator’s time efficiency.
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Computer Engineering. 2009, 35(18): 219-220. https://doi.org/10.3969/j.issn.1000-3428.2009.18.077By using the frame differencing algorithm and Random Sampling Consensus(RANSAC) matching algorithm based on Sampson distance, this paper realizes a multiple motion targets tracking based on temporal and spatial information. It gains the approximate position of motion target by using frame differencing algorithm, uses Harris algorithm to pick up the corner points of motion targets in every frame of video image and normalizes the configuration of these corner points. It uses RANSAC algorithm to match the corner points. A thresholding method is adopted to locate the position of the motion target. Experimental results show that this method can track similar targets with high precision and real-time performance.
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Computer Engineering. 2009, 35(18): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2009.18.078This paper proposes a unequal loss protection scheme for video stream. This scheme is suit for packet loss networks and Group of Picture(GOP) level oriented. By using the unequal significance in different frames in GOP, different amounts of Forward Error Correction(FEC) packets are allocated to different frames on GOP level. It adopts inter-frame packets interlacing mechanism to make this scheme more robust against burst packet loss. Simulation results show that this scheme can improve video receiving quality under different channel loss patterns.
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Computer Engineering. 2009, 35(18): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2009.18.079The spread-spectrum receivers implemented with FPGA+DSP model have many disadvantages, such as long exploitation period, great difficulty in realization. Aiming at this problem and based on System On a Programmable Chip(SOPC), the BD/GLONASS combination navigation positioning receiver is implemented in a single FPGA by using the embedded software core NiosII to instead of DSP processor and common controller. The algorithm principle and implementation methods of matched filter, correlator, carrier tracking loop and code tracking loop are described. The static positioning results of this receiver in twenty four hours show that its positioning precision satisfies the requirement.
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Computer Engineering. 2009, 35(18): 227-230. https://doi.org/10.3969/j.issn.1000-3428.2009.18.080Combining of fuzzy mathematics, fuzzy diagnosis principle and automatic detection technology, an expert system for ship log fault diagnosis based on fuzzy reasoning is proposed. According to the characteristic of ship log, it designs hardware platform and combines fuzzy relational matrix with semantic distance by fuzzy production knowledge representation method to design and realize each functional module of the ship log fault diagnosis fuzzy expert system. Experimental results show that the fault diagnosis fuzzy expert system is able to identify the fault efficiently and reliably.
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Computer Engineering. 2009, 35(18): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2009.18.081The advantages and disadvantages of Earliest Deadline First(EDF) schedule algorithm for real-time system are analyzed. To optimize the schedule of messages, the thought of relative-value and the schedule algorithm of maximal relative-value first with promotable relative-value are presented. This algorithm adopts multi-parameters to calculate the priority of messages. Experimental results prove that compared with traditional EDF algorithm, the improved algorithm fully makes use of bandwidth of the bus and optimizes the schedule of messages.
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Computer Engineering. 2009, 35(18): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2009.18.082Aiming at the structure of compute-intensive SoC that “one RISC main processor core + some dedicated co-processor cores”, this paper designs a memory access structure which supports a command-driven chunk data transfer. The structure is optimized with block-transfer and pipeline-transfer support. Experimental results show that the structure after optimization has high efficiency, low cost and well flexibility.
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Computer Engineering. 2009, 35(18): 237-239. https://doi.org/10.3969/j.issn.1000-3428.2009.18.083To study protocols and algorithms for Low Earth Orbit(LEO) satellite networks, a platform is built based on OPNET. The platform introduces the key points including topology design, node models, process models, link models and etc. It can simulate the procedures of routing table generation and packets routing in LEO satellite networks. Since satellite networks run regularly in the space, topology snapshot based static routing strategy is adopted, packets routing is simulated in an example satellite network, and the validity of the platform is proved.
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Computer Engineering. 2009, 35(18): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2009.18.084To meet the requirement of real-time and non-linear control of line-tracking robot, this paper presents a kind of control system based on μC/OS-Ⅱ and fuzzy control algorithm. μC/OS-Ⅱ is transplanted to make multitasks management and schedule. It contains fuzzy control of turning angle under the condition of double input of location and speed based on the maps’ and photoelectric sensor’s information fusion for the integrated navigation. Experimental Result shows that line-trcking control robot can travel steady in lots of different velocity and diverse conditions of road.
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Computer Engineering. 2009, 35(18): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2009.18.085This paper studies the problem of complex maintenance tasks scheduling and uses Matlab program to calculate several sets of distribution options which meet the constraints. After selecting the useful plans, the time-span of the total maintenance of the distribution options are calculated by using Genetic Algorithm(GA), so that the final plan with the shortest time is got and its Gantt chart is drew. According to the Gantt chart, it uses software Extend to simulate the scheduling process. The result proves that the time-span of the total maintenance of theoretic schedule is consistent with the time of Extend simulation, and it can save maintenance time effectively.
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Computer Engineering. 2009, 35(18): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2009.18.086This paper proposes a new method based on mixing matrix estimation for underdetermined blind speech separation, aiming at speech signals under weak sparseness. The method detects and esploits time-frequency bins with only one source by Principal Component Analysis (PCA) to estimate mixing matrix, it overcomes the shortcoming of weak sparseness of speech signals and improves the estimation precision of mixing matrix. It combines a subspace method to reconstruct the sources to improve the separation performance further. The subspace method is proved from geometric interpretation. Simulation results show the separability of the method is better than Cluster-BSS, and it robustness is better.
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Computer Engineering. 2009, 35(18): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2009.18.087This paper analyses the characteristic and development trend of the typical multi-discrete manufacture enterprise, bases on the accumulated orginal data of OA, MRP, PDM and SCM informatin systems, according to the four management level of general manager-department manager-workshop director-monitor to estabilish the single role decision-making model by role. It adopts the multi-attribute utility function and the arrangement analysis method to propose the multi-criteria decision-making model of manufacture facing the order of customer. An application example calculates the utility value of the decision criteria and alternative evaluation of the customers to choice the best customer.
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Computer Engineering. 2009, 35(18): 252-253. https://doi.org/10.3969/j.issn.1000-3428.2009.18.088This paper proposes a detection method of ST segment change in real-time Electrocardiography(ECG) monitoring, which uses line-fitting to extract the baseline, uses wavelet transform to monitor QRS complex, and combines J+X method and T wave detection method to attain the feature point of ST segment. A ST segment recorded message is designed in real-time monitoring. Through a long period of standard database simulation and clinical tests, this method is proved to be accuracy and useful.
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Computer Engineering. 2009, 35(18): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2009.18.089This paper proposes a First-Finished First-Scheduled(FFFS) algorithm of single-resource task schedule for the micro-satellite named EFFFS to resolve the conflicts among tasks which have an exclusion relation and the same priority, analyzes the performance of the algorithm, and compare it with other algorithms. Test results show that the algorithm has less time complexity and better performance, and it is suitable for the environment with limited computing resources.
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Computer Engineering. 2009, 35(18): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2009.18.090According to the requirements of spatial information visualization and location-based services of mobile subscribers, this paper presents a framework of 3D scene walkthrough system based on JSR-184 standard, designs and realizes the prototype, which includes scene model design, scene-tree construction, lights and cameras arrangement and user interaction. It puts forward the integrated modeling method of retained mode and immediate model and the strategy used in 2D-3D information switching. Test result demonstrates that the 3D scene system makes the mobile subscribers share the advantages in location-based service as those under desktop surroundings.
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Computer Engineering. 2009, 35(18): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2009.18.091The embedded wireless data transmission system consists of data service center and data terminal unit. Taking ARM7 microprocessor as core and combining the General Packet Radio Service(GPRS) communication network characteristic, this paper focuses on the design process of embedded wireless data transmission system, proposes the implement scheme in detail, analyzes its hardware component, the software system design process and development key problem and realizing process. Experimental result shows this system realizes the function of embedded wireless data transmission system based on GPRS.
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Computer Engineering. 2009, 35(18): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2009.18.092Clustering in Wireless Sensor Networks(WSNs) is an effective approach for organizing the network into a connected hierarchy. This paper proposes a novel clustering routing algorithm based on Adaptive Particle Swarm Optimization(APSO). Particle Swarm Optimization(PSO) is a typical swarm intelligence algorithm. It’s inspired by social behavior of bird flocking and acted as a fine optimization method. This advantage is utilized and improved to gain better convergence. Compared with Low Energy Adaptive Clustering Hierarchy(LEACH) algorithm, this protocol can reduce energy consumption and achieve better network lifetime.
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Computer Engineering. 2009, 35(18): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2009.18.093The two major different categories of Web mobile terminal devices are phone-type mobile devices of limited resource and personal mobile computers of “abundant” resource. This paper presents the self-adaptive terminal device framework which providing supports for developers to efficiently carry out the development and application of the mobile Web suitable for both the mobile devices of limited resource and the personal mobile computer. Based on the WWW protocol and WAP model, it makes use of technologies such as Filter, Dom4J, XSLT and Xpath by utilizing the existing successful open-source framework.
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Computer Engineering. 2009, 35(18): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2009.18.094Artifacts which are caused by the mutation noise disturbance often hinder Dynamic electrocardiogram(DCG) automated analysis and the correct diagnosis. The conventional wavelet denoising method can not eliminate this kind of artifacts. This paper proposes a new method for discriminating the artifacts which is based on multi-scale wavelets decomposition and threshold determination algorithm. Actual 30 group DCG data are used to test the algorithm. Experimental result shows that it is possible to quickly and effectively discriminate the artifacts, the reliability of this algorithm in accurately detecting the artifacts location is 96.4%, the new method is conducive for ensuring clinicians’ correct judgment of DCG signal.
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Computer Engineering. 2009, 35(18): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2009.18.095Aiming at the lack of flexibility of the existing hair model, a method for hair modeling and animation based on super-helix model is improved. This approach guides hair strands to cret helical segments with a finite number of degrees of freedom, and it uses Lagrangian mechanics for its equations of motion. By improving the method for calculating the curvature and twist of curly hair, the paer adopts a control structure named Adaptive Wisp Tree(AWT) for adaptive clustering and subdivision to increase the accuracy and stability during the process. Experimental result demonstrates the method can create realistic motion of hair.
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Computer Engineering. 2009, 35(18): 275-277. https://doi.org/10.3969/j.issn.1000-3428.2009.18.096A standard and open ear database is necessary to promote the development of ear recognition in theory and practical application. This paper design an ear collecting system to construct Chinese Ear Image Database(CEID), which includes 200 Chinese ear images. For each person, 3 sorts of illuminations and 4 shooting angles and 1 occlusion are considered in this ear database. Totally there are 6 400 ear images in CEID. Compared to other self-built ear databases of most institutes, the database is better in the number of samples and image shooting conditions at present. It is expected to play an important role in the research and evaluation of ear recognition.
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Computer Engineering. 2009, 35(18): 278-279. https://doi.org/10.3969/j.issn.1000-3428.2009.18.097This paper adopts image reconstruction method based on sub-Gaussian random projection to get a computer simulation experiment result using sparse projection matrix and very sparse projection matrix as measurement matrix. It proposes a compressed imaging system based on digital micromirror device, it presents system construction, the relation of components and the technique of design for key component. In order to satisfy the system need of detecting the weak light signal of high frequency changing, it designs a detecting component for weak light signal with single detector. Experimental result proves that the scheme is rapid speed, excellent preciseness and outstanding application.
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Computer Engineering. 2009, 35(18): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.18.098This paper establishes a profit equilibrium model in the center of recycling product for Third-Party Logistics Service(3PLS) in order to solve a profit equilibrium problem of recycling product in reverse logistics. It discusses the solution and optimization of the model by equilibrium method of dynamic game with incomplete information based on product disposal cost and sell again profit, realizes benefit optimized for two contrary models. Example proves that the model can realize maximum benefit of 3PLS.
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Computer Engineering. 2009, 35(18): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2009.18.099This paper processes speech feature extraction based on wavelet packet analysis aiming at speech-driven lip movement synthesize. It uses feature difference and multi-frames speech based on association relationship of lip frames to express dynamic characteristic for speech, utilizes Principal Component Analysis(PCA) to reduce dimensions of the input speech. It introduces speech-visual mapping models based on Input-Output Hidden Markov Model(IOHMM) to obtain speech-driven lip movement synthesize system. Experiment indicates that speech features are more robust than traditional Mel-frequency cepstrum coefficient, can synthesize coherent and natural lip sequences.
2024
Volume 50 No 3
Volume 50 No 3
(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