20 March 2009, Volume 35 Issue 6
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Computer Engineering. 2009, 35(6): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.06.001For the needs of communication between a variety of communication networks and interfaces in the same network which coexist in large-scale systems, a conversion module which supports communication between a variety of communication networks and interfaces is developed based on LPC2368 and the real time operating system of RTL-RTX. The module supports the communication between Ethernet, serial network, CAN(fieldbus network) and USB, as well as RS232, RS422 and RS485 communication interfaces. The limit conditions to use the conversion module are pointed out based on the quantitative analysis for the conversion rate in the network wire-speed.
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Computer Engineering. 2009, 35(6): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.06.002This paper proposes a novel routing algorithm based on Ant Colony Algorithm(ACA) for Wireless Sensor Networks(WSNs), which is in spirit of the advantages of clustering algorithm and ACA. It considers the influence of the remaining power, so it is able to balance the consumption of node power, and it uses positive feedback of ACA to find the optimal multihop routing from the cluster head to the sink node. Simulation result shows that the algorithm is rational and efficient in WSNs.
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Computer Engineering. 2009, 35(6): 7-10. https://doi.org/10.3969/j.issn.1000-3428.2009.06.003This paper makes a concise introduction to seven classic algorithms of triangular mesh subdivision, and makes a classification and comparison between them according to their continuity, own advantage and application status. In order to improve the visualization of triangular mesh subdivision, interactive display control is implemented by using MFC and OpenGL while state machine model based on functional class is used as the software operating pattern. On the basis of this, the prototype implementation of Loop algorithm is performed. The improved method of solving existing problematic issues from prototype implementation is presented.
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Computer Engineering. 2009, 35(6): 11-13. https://doi.org/10.3969/j.issn.1000-3428.2009.06.004Traditional context prediction approach is to predict context based on the single user’s context records, but in real ubiquitous or pervasive computing environment, the change of user’s context is mostly due to interactive activity of users. In order to solve the problem above, this paper presents a context prediction approach based on interactive-context, gives the concepts of interactive-context and interactive-context prediction, and introduces the modeling of interactive-context and the reasoning algorithm of interactive-context prediction.
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Computer Engineering. 2009, 35(6): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2009.06.005Compared with the topology of full-connected network, a method for evaluating network invulnerability is proposed based on average equivalent shortest way. It shows that the more the average equivalent shortest ways are, the better the network invulnerability is. A method to evaluate node importance is proposed based on invulnerability degradation percentage after one node being destroyed. The larger the percentage is, the more important the node is.
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Computer Engineering. 2009, 35(6): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2009.06.006As for the scale of the problem and the system continues to expand, the cluster-based high-performance computer is facing scalability, reliability, power consumption, footprint, balance, and many other challenges. This paper introduces the design and realization of high-productivity computing node such as computing module, switch module, management module, adaptive power management, FPGA-based hardware accelerator board, high-speed PCI-E switch extend module and other aspects. It resolves the computing density, I/O expansion and bandwidth bottleneck as well as energy consumption and other bottlenecks in Dawning 5000A 100 Teraflops supercomputer based on the high-productivity computing node.
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Computer Engineering. 2009, 35(6): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2009.06.007To the point of many evaluation metrics are fuzzy and the information which describes the metrics is partial in Mobile Ad Hoc Network(MANET), this paper presents a comprehensive evaluation method for routing protocols based on credibility. This method constructs evaluation metric model of credibility based on IETF RFC 2501. Combined with gray evaluation method and hierarchical analysis method, the subjective factors on evaluation functions of routing protocols are reduced to minimum. The value of credibility is more objective and accurate. It ensures that the user can choose effective routing protocol according to evaluation result and requirement. Experimental results prove the effectiveness of this method.
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Computer Engineering. 2009, 35(6): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2009.06.008Dynamic Source Routing(DSR) and Ad Hoc On-demand Distance Vector routing(AODV) protocols are most typical single-path routing protocols, which support mobile node, self-organization and self-configuration network. The multi-path variants of DSR and AODV are extension of DSR and AODV. This paper compares performance of multi-path variants in hybrid wireless Mesh networks and mobile Ad Hoc networks by simulation. Result shows that, multi-path variants based on hybrid wireless Mesh networks have such feature as more higher packet delivery ratio, more lower end-to-end average latency and routing overhead. The multi-path version of DSR can be applied to highly mobility environment due to prominent improvement of performance under dynamic network environment.
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Computer Engineering. 2009, 35(6): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2009.06.009Aiming at the object recognition problem with multiple characteristic indexes for the fuzzy multi-sensor, a new fusion method for the fuzzy multi-sensor data is proposed. According to the theory of information entropy, the method introduces the disequilibrium index to define the vector of entropy weight. By solving the mathematical programming, the optimal membership degree for each target type is obtained, and the rule of object recognition is given. The method improves the objectivity and trustworthy degree of recognition result. The applied example proves that the method is exercisable.
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Computer Engineering. 2009, 35(6): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2009.06.010According to the fairness problem in Active Queue Management(AQM) algorithm, this paper proposes a novel fair AQM algorithm namely RFED. By imposing effective punishment upon non-responsive flow, it ensures the fairness of different flow. And it maintains queue arrival rate at or below queue service rate through more reasonable dropping probability according to the arrival rate. Simulation results show that the algorithm outperforms RED, CSFQ and CHOKe in stabilizing instantaneous queue length and fairness.
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Computer Engineering. 2009, 35(6): 32-34. https://doi.org/10.3969/j.issn.1000-3428.2009.06.011This paper builds a vision sensor for occupant classification based on low cost CMOS camera and an intelligent pattern recognition algorithm, which focuses on the 5th female(runty female) and the 50th male(average stature male), etc. The image pretreatment algorithm and occupant image edge detection algorithm are founded. The critical properties of occupant edge are described by Legendre moment. The pattern classifier based on the BP neural network is set up. The pattern classification of different occupant types is realized.
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Computer Engineering. 2009, 35(6): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2009.06.012Camouflage pattern development gradually departs from its bionics origin, so a series of unsolvable problems appear. This paper proposes the concept of bionic camouflage pattern. It introduces the camouflage pattern design technique blended with biologic character, and lays a strong emphasis on the clustering of background picture and the creation of bionic structuring element. Four typical bionic camouflage patterns are designed. Then camouflage effectiveness of bionic camouflage pattern is tested through edge detection and correlation tracking. The research result indicates that the camouflage effect of bionic camouflage pattern is good enough for military target camouflage, whether static or dynamic.
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Computer Engineering. 2009, 35(6): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2009.06.013In order to adapt to the requirement of MPEG-4 object-oriented operations, Region Segmentation based on Video Object (RSVO) is proposed. The mean shift process can be performed in the area of video object. RSVO can speed up calculating time and save memory compared with traditional mean shift method, and it is suitable for situation where high speed is needed and memory resource is restricted. In order to save calculating time while guarantee high quality for the region of interest, results of RSVO are used to area-directed image interpolation. Experimental results show the validity of the method.
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Computer Engineering. 2009, 35(6): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2009.06.014Combined with the practical requirement in the informatization process of the China Telecom Commission, JavaEE architecture is introduced, and a method for developing large scale telecom Custom Relationship Management(CRM) data persistent layer on the platform of JavaEE. This paper also analyzes the application of façade pattern, VO pattern and DAO pattern in the Spring JDBC framework, which implements the loose coupling in persistent layer. The whole system has better performance of stability, flexibility and extension.
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Computer Engineering. 2009, 35(6): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2009.06.015To solve the problem of word-mismatch between query key words and document words, this paper puts forward a query expansion algorithm based on the combination of association rules and cluster algorithm. At the first stage it uses association rules on the front N documents in the first query result, and gets the rules that have query item to build the rules base, and gets the K words that have the most similarity with the query words to form a new query and query again to get a new result. At the second stage it uses cluster algorithm on the new result and compute every document’s final similarity to get a document re-ranking. Experimental result shows this query expansion algorithm outperforms both the association rules and the cluster algorithm.
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Computer Engineering. 2009, 35(6): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2009.06.016From the viewpoint of software engineering implementation, a MDA-based development approach for Web applications is proposed. The development process starts from the describing of platform independent models. Mapping relations from the source model to the target model are built according to the syntactic structure and semantic features of both metamodels, and model transformation as well as code generation can be achieved subsequently. ASP.NET is used as a target platform in the experiment which shows that this approach follows the essence, process and requirements of model-driven architecture, and thus can make an effect support for model driven software engineering.
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Computer Engineering. 2009, 35(6): 50-51. https://doi.org/10.3969/j.issn.1000-3428.2009.06.017This paper introduces the definition, the characteristic and the limitation of PageRank algorithm used by Google and other search engine. It develops a system, ocean search system, which is based on Ontology and PageRank algorithm. However, because of PageRank algorithm’s insufficiencies in this system, a new algorithm is proposed and applied in the system’s consummation. It introduces the functions of the ocean search system and takes an illustration and test to the new algorithm.
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Computer Engineering. 2009, 35(6): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2009.06.018Crosscutting concerns are functionalities that distribute in many modular units, and Aspect-oriented Programming(AOP) is one of the most effective methods to solve this problem. An important question in AOP is how to identify crosscutting concerns from object oriented legacy system. A method based on dynamic behavior and fuzzy pattern recognition for Aspect mining is presented. The method uses Aspect to capture the runtime method for calling information and providing the ability of auto-collecting dynamic information. It uses fuzzy pattern recognition to identify the crosscutting concerns. An experiment is conducted in order to verify the validity of the method. The implementation of this method is simple and succinct.
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Computer Engineering. 2009, 35(6): 55-56. https://doi.org/10.3969/j.issn.1000-3428.2009.06.019Aiming at the space-time problem during the process of which reduct is figured out by discernibility matrix in rough sets, the principle and algorithm of discernibility matrix time-consuming calculating are raised, which includes two time-consuming periods calculation and result reliability verification. The data processing time-consumed by discernibility of matrix is predicted, and the feasibility of data mining experiment is forecasted.
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Computer Engineering. 2009, 35(6): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2009.06.020A storage system model is given based on Quality of Service(QoS) according to the object storage characteristics. This model divides the migration task into some migration requests, which makes object storage device respond I/O request as it migrates data from one site to others. At the same time, the metadata server assigns the income to the I/O and the migration request according to the same criterion, which make the storage devices respond the both request by the maximum income algorithm and provide the better QoS. The maximum income algorithm is online realized by income forecasting and bandwidth obligating. Experiment proves that the maximum income algorithm has less infection to I/O performance than the migration first algorithm and the fixed migration rate algorithm.
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Computer Engineering. 2009, 35(6): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2009.06.021Fuzzy C-Means(FCM) clustering algorithm can not deal with updated data, so this paper presents Incremental Clustering Algorithm Based on Adaptive FCM namely AIFCM. It combines the density with data set, and can automatically decide the prototypes of the clusters and the number of the clusters when the cluster is splitting. It can deal with updated data filter the outliers and satisfy with the requirement of users.
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Computer Engineering. 2009, 35(6): 63-65. https://doi.org/10.3969/j.issn.1000-3428.2009.06.022Web-based forum is one of important applications on Internet. More and more research has been focused on it, such as topic analysis, trend analysis. This paper concentrates on the statistical character of the posting number in Web-based forum. By means of variance analysis and R/S analysis, finds that self-similarity generally exists in Web-based forum. A generative model based on time-delay levy distribution is proposed to describe the kind of property. Theoretic and simulation analysis are done to verify the effectiveness of the model and show that the computation complexity is low.
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Computer Engineering. 2009, 35(6): 66-68. https://doi.org/10.3969/j.issn.1000-3428.2009.06.023Current workflow modeling languages are difficult to balance both understandability and formal execution semantics. They can only describe workflows in a single dimension. This paper suggests using process model as a workflow modeling language. Process model depicts the business flows of enterprises from multi-dimensions such as process, data, resource and organization. Based on the syntax of process model and characteristics of workflow systems, a formal execution semantics of process model is presented. The semantics is theoretical basis for model analysis, verification and execution.
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Computer Engineering. 2009, 35(6): 69-72. https://doi.org/10.3969/j.issn.1000-3428.2009.06.024Aiming at the problems existed in traditional replication technology, and on basis of analyzing the High Availability(HA) system structure for complex storage network, a Recovery-Oriented self-Adaptable Replication Protocol(ROARP) and a Recovery-Oriented Request Recording and Checkpoint(RORRC) are designed, which allows multiple replication groups exist in one system, and each member of the group is active. Experimental results show these novel protocol and algorithm are fit for varied complex storage networks.
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Computer Engineering. 2009, 35(6): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2009.06.025Information model mapping is the key problem to realize the WS-based network integrated management system. Based on analyzing WSDM management capability and SNMP management information, a layered WSDM-SNMP information model mapping framework is proposed. The mapping mechanism on syntax and semantic is described. SNMP-WSDM bridge is realized.
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Computer Engineering. 2009, 35(6): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2009.06.026In order to solve the problem of ontology heterogeneity in semantic Web, an ontology integration description based on category theory is proposed. Compared with set theory, category theory is more abstract and its representation is stronger, so it is perfect tool to formalize ontology integration. Taken the ontology structure as object, the concept of “morphism” captures the idea of ontology mapping and “pushout” is used to merge ontology. Examples are used to illustrate the problem and the algorithm of ontology merging is presented.
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Computer Engineering. 2009, 35(6): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2009.06.027Aiming at serious thesis copying problems, this paper presents systematic frame model of ontology-based thesis copy detecting system which is based on analysis about foreign and domestic researching method and existing problems, and describes framework of thesis copy detecting system from three layers, such as ontology access layer, and ontology represent layer, ontology map layer. Semantic and ontology technology is utilized to discuss the build of paper ontology and calculation of paper similarity, which has certain theoretical meaning for the build of thesis copy detecting system.
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Computer Engineering. 2009, 35(6): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2009.06.028According to the multivalue bios of ID3 algorithm, an ID3 improved algorithm, NewDtree, is brought forward in the paper. This algorithm is based on the attribute similarity theory, solving the multivalue bios, and the multivalue bios in NewDtree algorithm is proved not exist with the analytical method of the theory. A conclusion is drawn with the analysis of test result that the NewDtree algorithm can improve the definition of classification effectively, solving the multivalue bios problem of ID3 in selecting test attribute.
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Computer Engineering. 2009, 35(6): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2009.06.029FM-index is an advanced compressing information index method in the world. It is an integration of compressing technology and index technology, which supports enquiry of source files under the uncompressing circumstance. This paper researches FM-index compressing in blocks, focuses on the improvement of the capability. Through theoretical analysis and detailed data, analysis and comparisons are made regarding the time and space that FM-index and Winrar take respectively, which demonstrates the improvement of FM-index method.
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Computer Engineering. 2009, 35(6): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2009.06.030A relevancy coefficient vectort space model named cVSM is proposed to aim at Web spams which flood in blogosphere and forums. The cVSM whose components are employed as features of comments and the support vector machine classification algorithms are used to automatically identify comment spams. The relevancy coefficient included in the cVSM is presented, which is used to evaluate relevancy grade of posts and comments. Chinese blog dataset and Chinese BBS dataset are tested. Experimental results show that compared with traditional method the F1 has been improved at least 6% by this way.
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Computer Engineering. 2009, 35(6): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.06.031PIM-SM protocol is usually used to implement the data transmission of IPTV multicast, but this protocol can not control the multicast source, which makes IPTV service not process in gear. To solute this problem, this paper presents a scheme of IPTV multicast source control on edge router. Simulation results indicate this scheme can fulfill the function of IPTV multicast source control.
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Computer Engineering. 2009, 35(6): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2009.06.032In a hybrid P2P system, gossip adaptive algorithm promotes the efficiency of resource search. Against the contradiction in the randomized gossip algorithm between the redundant information in the transmission method and consistency of the resource popularity, this paper introduces a new transmission method based on the node address. The method avoids the duplicate sending upon the node address, which results in less transmission time and cost than randomized gossip algorithm in the experiment.
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Computer Engineering. 2009, 35(6): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2009.06.033A novel delay-constrained Steiner tree algorithm based on local domain QoS information is presented, which constructs a multicast tree along the shortest cost paths, and on the basis of the least delay path information provided by group members and Source Area Border Routers(SABR), the source node computes the best routes for remain members. Then, the control messages are sent out to configure the multicast tree and break loops. This algorithm is not dependent on global QoS information, so it can cut down control overheads greatly and be immune from stale QoS information. Simulation experimental results show this algorithm has high join success rate and reasonable control overheads.
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Computer Engineering. 2009, 35(6): 100-101. https://doi.org/10.3969/j.issn.1000-3428.2009.06.034To analyze communication link importance to end-to-end communication in communication networks, a link importance calculation method based on the number of routes is proposed. The method finds all routes of end-to-end by a rapid algorithm, then compares the reduce number of routes after different link is destroyed, and estimates different link importance to end-to-end communication. The more drastically decreases the number of routes because of destruction of a link, the more important this link is. A calculation example shows the method is simple. It is easy to be realized by program, and has practicability and validity.
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Computer Engineering. 2009, 35(6): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2009.06.035Aiming at the problem of the difficult circumstances of system maintenance caused by tight coupling of bottom equipments and upper software in many engine monitoring systems, this paper uses the combination of bridge and adapter pattern to design the bottom data acquisition interfaces, which implements the loose coupling between field devices, remote monitoring clients and data gateway. The technology of Distributed Component Object Model(DCOM) is made as the data processing model, so that the server can provide remote distributed database services. Experimental result proves that this design approach implements multi-protocol and multi-model compatible of the bottom equipment, reduces maintenance costs, and has better reusability and scalability of the system architecture.
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Computer Engineering. 2009, 35(6): 105-106. https://doi.org/10.3969/j.issn.1000-3428.2009.06.036A novel routing scheme for Mobile Ad Hoc Networks(MANETs) DSR-Ant on-demand routing protocol is proposed in this paper. It overcomes the shortcomings of the DSR protocol and ant-based routing protocol by combining them and adding new routing mechanisms to enhance their capabilities and alleviate their weaknesses. Simulation results show that DSR-Ant on-demand routing protocol is more proper to real-time communication due to its low end-to-end delay and high connectivity.
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Computer Engineering. 2009, 35(6): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2009.06.037In structured P2P networks, the skewness in query pattern can result in load imbalance and even congestion. To address the problem, this paper presents a dynamic congestion control algorithm based on indegree adjustment approach. The basic idea behind the algorithm is that it dynamically identifies a group of nodes near a hot spot and then reallocates loads among them by indegree migration. The results of the simulation experiments show that the algorithm can effectively reduce the level of congestion in case of load burst with a low overhead.
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Computer Engineering. 2009, 35(6): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2009.06.038This paper proposes a new MAC protocol named Self Adaptive SMAC aiming at the deficiencies of back off mechanism in SMAC. Self Adaptive SMAC introduces the exponential back off mechanism based on SMAC, and then analyzes the key performance parameters of the back off process using Markov model. According to the results of the analysis, it further introduces a counter to accumulate the times of busy state of the communication channel, through which nodes have the ability to estimate the congestion situation of the channel. It adaptively changes the size of collision window to reduce collision according to the information about congestion situation, consequently the energy efficiency and throughput are improved. The simulation results later show that Self Adaptive SMAC has better energy efficiency and better channel utilization compared with the original protocol SMAC.
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Computer Engineering. 2009, 35(6): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2009.06.039Aiming at the problem that two-window algorithm can not judge the dropped packets marked type, a novel judgement method for dropped packets marked type is proposed, which extends the SACK chunk of SCTP, and the dropped packets’ marked type information is obtained from the extended SACK chunks. Simulation experiments are made in NS2, and the results indicate the improved SCTP achieves more throughput.
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Computer Engineering. 2009, 35(6): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2009.06.040Most existing network traffic supervision systems focus on the volume of traffic, and do not analyze information contained in these data. This paper utilizes entropy to capture the change of network traffic feature distribution, such as source IP address, target IP address, target port, and analyzes network traffic from the standpoint of feature distribution. It implements a supervision system by using this method. Experimental results show that this system has a higher detecting rate and a lower fault rate.
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Computer Engineering. 2009, 35(6): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2009.06.041With the increase of network service types and users broadband demand, Broadband Wireless Access(BWA) has become the focus of people’s attention. This paper introduces the Mesh mode of IEEE802.16, discusses congestion control in Mesh mode, and presents a new method through dynamically adjusting the exponent of transmission holdoff time and allocating minislot to control congestion. Simulation results show that the congestion can be controlled effectively, throughput is increased, packet loss rate and end-to-end delay are decreased.
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Computer Engineering. 2009, 35(6): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2009.06.042This paper analyzes the up-down layer topology of multi-source media streaming network, and presents a topology optimization strategy based on loading balance. This strategy makes use of the abundant network resource by P2P technology and combines media servers function with group broadcasting theory. It can make all media streaming network’s topology balanced, and bring on all system’s loading balanced. Playing delay is reduced, and system stability is enhanced when system expansibility is ensured.
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Computer Engineering. 2009, 35(6): 125-126. https://doi.org/10.3969/j.issn.1000-3428.2009.06.043This paper researches the problems of time, space and flow coupling in distributed asynchronous communication, and analyzes current problems of communication in distributed object-oriented middleware. It adopts Publish/Subscribe(P/S) scheme in CORBA distributed environment and establishes CORBA communication based on P/S scheme. It specifies the architecture, encapsulation and design of interface. The technology for supporting this communication arithmetic is explained.
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Computer Engineering. 2009, 35(6): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2009.06.044This paper introduces NAT-PT’s technology principle, depicts the concept of NAT-PT protocol translation gateway and its system framework. According to RFC 2766 document and RFC 2765 document, and referring to source codes about the realization of IPv4/IPv6 network in Linux kernel, it designs and implements NAT-PT gateway application program, which is composed of main model, application level gateway model, network address translation model and protocol translation model.
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Computer Engineering. 2009, 35(6): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2009.06.045The development of distributed application in Mobile Ad Hoc network(MANET) faces many challenges, so it is important to introduce content-based publish/subscribe middleware in it. This paper proposes a novel content-based routing protocol. It constructs an optimized dynamic dissemination mesh and propagates events only to the matched subscription nodes. Unnecessary propagation of events is confined. Experimental results show that the protocol decreases the total cost of the network and saves network bandwidth largely, which boosts the scalability and performance of the system.
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Computer Engineering. 2009, 35(6): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2009.06.046Location is foundation work in Wireless Sensor Network(WSN). Existing location algorithms need the position information of beacon nodes to locate the non-beacon nodes. When the position information is affected by the attacker or errors, the accuracy of these algorithms will degrade. This paper combines the LS localization algorithm and Metropolis-Hasting sample algorithm, and proposes an improved LS localization algorithm. It constructs a simulation circumstance which might be attacked and compares the improved algorithm with original algorithm. Experimental results demonstrate that the improved algorithm has better robustness than original algorithm.
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Computer Engineering. 2009, 35(6): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2009.06.047Available bandwidth is a main parameter of the network performance. This paper discusses the presented algorithm for bandwidth measurement, and analyzes the background flow rate and the queue of data packet, which discovers the inherent characters of the error for estimation value. A simulation test environment is designed and set up, and based on the load of the path and the variety of background flow rate, the publicly available bandwidth estimation tools such as Pathload and Spruce are tested.
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Computer Engineering. 2009, 35(6): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2009.06.048An anonymous authentication protocol is proposed to improve the anonymity and to control anonymity abusing for wireless communications. The protocol implemented the anonymity of Home Location Register(HLR) using Visitor Location Register(VLR) which has been employed to forward the authentication message by Mobile Station(MS). Through checking the authentication token, this protocol can control anonymity abusing. The probability statistics is adopted to analyze the security and anonymity of this protocol. The analysis results show that this protocol not only improves the anonymity of HLR but also defends anonymity abusing effectively.
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Computer Engineering. 2009, 35(6): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2009.06.049This paper proposes a method of steganalysis based on JPEG binary compressed stream, which is different from the steganalysis based on Discrete Cosine Transform(DCT) frequency domain and image spatial domain. It utilizes the changes of binary compressed data stream caused by the hidden messages, and uses Multiple Embedding Method(MEM) to draw a feature vector, which is used to train the One Class Support Vector Machine(OC-SVM). OC-SVM get high classification rate towards JSteg and Outguess hiding methods in the experiment.
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Computer Engineering. 2009, 35(6): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2009.06.050According to the characteristics of Wireless Sensor Networks(WSN) and the defects in current key management schemes, a key management scheme(KMSBDK) based on deployment knowledge is presented using Identity-Based Cryptography(IBC). The scheme is analyzed from security, key connectivity, scalability and efficiency. Compared with some current popular schemes, KMSBDK achieves better performance.
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Computer Engineering. 2009, 35(6): 148-149. https://doi.org/10.3969/j.issn.1000-3428.2009.06.051A more security analysis on the ID-based Authenticated Group Key Agreement(ID-AGKA) is given and it is found that the ID-based AGKA does not resist outsider attack, that is, an adversary can make a group session key inconsistent, which can not be detected by the users in the group however. An improvement of the AGKA scheme is proposed. Security analysis shows the scheme can resist outside attack.
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Computer Engineering. 2009, 35(6): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2009.06.052The analysis of verifiable secret sharing scheme without trusted authority shows it has not the perfect forward-security property. Aiming at this problem, a generating group key scheme with perfect forward-security property is proposed, which is based on the Elliptic Curve Cryptosystem(ECC) and Shamir’s threshold idea. In this scheme, the received messages are verified by participants. It also helps counter the attacks both from active attackers and passive attackers, and the system does not need secure communication, which declines the system cost. Experimental results indicate this scheme has better security and higher computing efficency.
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Computer Engineering. 2009, 35(6): 153-155. https://doi.org/10.3969/j.issn.1000-3428.2009.06.053The conventional protocol of platform attestation has passivity and cheat problem in practice because of using nonce. This paper proposes platform attestation based on time, which uses transport session associating attestation with time in application layer. Equipment can upload attestation report actively on time and record log in the situation of network disconnection.
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Computer Engineering. 2009, 35(6): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2009.06.054Attack impact detection is important to the defence of buffer overflow attack. Windows Native APIs are proper data resource of attack impact detection. This paper proposes the concept of execution profile and the establishment method. Through the analysis of buffer overflow attack impact, buffer overflow attack impact detection based on process execution profile is proposed. Experiment illustrates this method is valid.
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Computer Engineering. 2009, 35(6): 159-161. https://doi.org/10.3969/j.issn.1000-3428.2009.06.055According to security request of mobile Internet, an identity-based cryptography mutual authentication PANA protocol is proposed to solve the problem of AAA protocol in mobile communication. It can provide anonymous service that guarantees the confidentiality of the mobile users’ identity. Research results show that the protocol has a good anonymous property, it is efficient and feasible, and is suitable to be applied in wireless mobile Internet.
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Computer Engineering. 2009, 35(6): 162-163. https://doi.org/10.3969/j.issn.1000-3428.2009.06.056An image encryption algorithm based on composite discrete chaotic system is presented. Composite discrete chaotic system provides chaos sequence. This paper proposes an algorithm of chaotic images confusing based on the sort transformation. Theoretical analysis and simulation experiment show that, the algorithm guarantees the security of the encryption effectively and excellent performance against attack.
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Computer Engineering. 2009, 35(6): 164-165. https://doi.org/10.3969/j.issn.1000-3428.2009.06.057Based on the theory of forward-secure digital signature and proxy signature scheme, a new forward-secure proxy signature scheme is proposed under the use of bilinear pairings. This scheme is to preserve the validity of past proxy signature even if the current secret key of proxy signer has been compromised. It not only has the properties of proxy signature, such as verifiability, unforgeability, undeniability, but also has the properties of forward security.
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Computer Engineering. 2009, 35(6): 166-169. https://doi.org/10.3969/j.issn.1000-3428.2009.06.058With Walsh spectrum of Boolean functions, a necessary and sufficient condition is given on Boolean functions satisfying k-strengthened propagation criterion. Based on the relationship between k-strengthened propagation criterion and k-propagation criterion, two constructions of Boolean functions satisfying k-strengthened propagation criterion are presented. With Walsh spectrum of Boolean functions satisfying balance and correlation immune, a necessary and sufficient condition of the defining functions of k-cheating immune secret sharing is obtained.
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Computer Engineering. 2009, 35(6): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2009.06.059Pattern matching computations dominate in the overall cost of running a Network Intrusion Detection System(NIDS). With network speed and the number of rules constantly increasing, pattern matching as a key component, is becoming the bottleneck in NIDS. Existing approaches to match pattern mostly apply statically-defined optimizations that do not take into account the characteristics of the network traffic and attack signatures. This paper proposes an adaptive multi-pattern matching algorithm specifically designed for network intrusion detection system, called AMPM. AMPM dynamically captures traffic and rules properties and intelligently selects the best suitable algorithm to detect packets. Experimental results show that the performance of existing NIDS applying AMPM improved by 9.4%~29.1% and AMPM is more appropriate for large rule set.
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Computer Engineering. 2009, 35(6): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2009.06.060In P2P network, an important challenge is how to cope with P2P system security problem and improve the availability. This paper presents a new trust model FGTrust. Fuzzy set which is used for presenting the trust value. The model uses the grey relation degree to express veracity degree of recommend and adjusts the weight value. A definition of risk is presented and quantified by using information entropy. By doing this, it can evaluate the trust relationships between peers more precisely. The proposed model can evidently enhance ratio of successful transaction.
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Computer Engineering. 2009, 35(6): 176-177. https://doi.org/10.3969/j.issn.1000-3428.2009.06.061Some kinds of communication errors occur during the communication process of fieldbus. Applying functional safety on the fieldbus technology can eliminate some of these errors. This paper describes Ethernet for Plant Automation(EPA) functional safety communication model. Several measures are used to detect different communication errors, such as time stamp, sequence number and CRC. The message structure of EPA functional safety protocol layer is presented. The realization process of functional safety protocol layer is depicted.
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Computer Engineering. 2009, 35(6): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2009.06.062In current worm simulation, network simulators drop the scanning packets sent to invalid IP addresses, which will underestimate the traffic brought by worm. This paper focuses on the problem, introduces a modified routing strategy for worm simulation and implements the idea in the network simulator GTNetS. In order to quantitatively compare the differences between original routing strategy and the modified one, an ideal model is presented and several experiments are made. Simulation results show that worm traffic is more accurately reflected after routing strategy is modified.
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Computer Engineering. 2009, 35(6): 181-182. https://doi.org/10.3969/j.issn.1000-3428.2009.06.063This paper proposes a modified SHA-x Hash algorithm on the basis of the Secure Hash Algorithms(SHA-1 and SHA-2) defined in FIPS PUB 180-2. The new algorithm increases the message digest length from 160 bit of SHA-1 to 192 bit. As a result, in contrast to the standard SHA-1 algorithm, the main advantage of the new scheme is that the number of bits of security provided for the data being hashed is improved. Secure analysis shows that since the computation method of addition modulo 232 is kept, the computation speed of the modified algorithm will not be slowed down excessively.
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Computer Engineering. 2009, 35(6): 183-185. https://doi.org/10.3969/j.issn.1000-3428.2009.06.064Aiming at the exhaustive attack and Man in The Middle attack on the key, algebra attack on E0 algorithm of the baseband encryption scheme, this paper proposes a new encryption scheme on the HCI layer, based on the features of Bluetooth devices. It protects the security of key with improved ECDH protocol. Experiment demonstrates the scheme provides more security mechanism and solves the impact on communication under reliable transmission, and the style of improved AES algorithm has less impact on communication.
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Computer Engineering. 2009, 35(6): 186-187. https://doi.org/10.3969/j.issn.1000-3428.2009.06.065The anonymous authentication schemes for Trusted Computing Platform(TCP) is studied in this paper, the advantages and disadvantages of the subsistent authentication schemes for TCP are analyzed. A new anonymous authentication scheme for TCP is proposed by using the method of zero-knowledge proof. The validity of a TPM platform is proved anonymously, and there is no trusted third party to participate in the authentication schemes. The new scheme has higher efficiency than others and satisfies forgery-resistance, anonymity and revocation under strong RSA assumption and Diffie-Hellman assumption in the random model.
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Computer Engineering. 2009, 35(6): 188-191. https://doi.org/10.3969/j.issn.1000-3428.2009.06.066This paper studies the statistical models of natural texts, and points out that embedding messages in texts may change the features of them by analyzing the statistical features. Based on these changing, a blind detecting method is designed using Support Vector Machine(SVM). It extracts five basic parameters of texts as distinguished feature vectors to discriminate natural texts and stego-texts effectively using SVM. Experimental results show the high accuracy and reliability of the method.
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Computer Engineering. 2009, 35(6): 192-193. https://doi.org/10.3969/j.issn.1000-3428.2009.06.067The random number generated by random sequence generator based on Linear Feedback Shift Register(LFSR) has low linear complexity. This paper proposes a new random sequencer generator to solve this problem. Genetic algorithm is used to evolve the sequences produced by LFSR to improve the linear complexity of the random number generator based on LFSR. The new sequence can pass the statistical test suit SP800-22. The result of tests shows the new sequence owns longer period and higher linear complexity, meeting the requirements of security protocols and encryption.
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Computer Engineering. 2009, 35(6): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2009.06.068For the secure problems existing in current E-mail systems, this paper establishes the mail server which filters the spam and virus, and the gateway server which filters the secret-involved mails. It accomplishes the secure mail client and the manage control center with the technology of identity-based cryptography and content-based filtering. The system can provide safe communications between these enterprise employees who are uncontrollable and dynamic.
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Computer Engineering. 2009, 35(6): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2009.06.069It is too expensive for distributed firewall built by NP to dispose them to hosts, so this paper gives a solution of an embedded firewall based on ARM processor to solve the problems. The hardware of embedded firewall is designed into core board and expanded board. It designs U-Boot, migrates the embedded OS, and implements NIC driver and packet filter. Test results show that this firewall is powerful and its security is enhanced with a low cost.
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Computer Engineering. 2009, 35(6): 200-201. https://doi.org/10.3969/j.issn.1000-3428.2009.06.070To solve the problem of getting a more precise result of comprehensive evaluations, fuzzy neural network method is introduced. This method uses a network training algorithm to cope with subjective factors in evaluations model. The algorithm can efficiently approximate the weight set and degree of membership function. To enhance its validity, many skills are adopted to optimize the network training process. The results show that the strategy can efficiently improve the final precisions. It is a better solution for synthesis evaluations problem.
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Computer Engineering. 2009, 35(6): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2009.06.071Aiming at the disadvantages of detecting traffic sign with RGB or HIS color space values respectively, a novel traffic sign detection method with multi-channel integration is proposed. The HIS color space values are converted from RGB values through image color space transformation. Sub-variable S in image segmentation is processed based on the iterative Otsu threshold value algorithm. The color is clustered based on the information of hue and saturation, combining with the color-character of RGB channel. The circum-rectangle is got with horizontal and vertical projection. It allocates and assorts the traffic sign with the least square method of curve fitting. Experiment shows that the method can abstract traffic sign from background precisely, even under the circumstance of brightness changing, noise interferences or azimuth obliquity.
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Computer Engineering. 2009, 35(6): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2009.06.072This paper presents a novel Mutable Simulated Annealing Particle Swarm Optimization(MSAPSO) algorithm for solving the QoS unicast routing problem. A new ⊕ operator is used in MSAPSO, which can simplify the iterative formulas of Particle Swarm Optimization(PSO) into a single one. In order to improve the diversity and the convergence of the algorithm, it designs a mutable Simulated Annealing(SA) operator, which joins the mutation operator of Genetic Algorithm(GA) and metropolis rules of SA into PSO. The results show that the MSAPSO is superior to PSO and Ant Colony Optimization(ACO) in convergence and searching success rate.
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Computer Engineering. 2009, 35(6): 208-209. https://doi.org/10.3969/j.issn.1000-3428.2009.06.073Knowledge Evolution Algorithm(KEA)is a new optimization algorithm based on mechanism of knowledge evolution. The method based on knowledge evolution algorithm is proposed to solve knapsack problems. The detailed realization of the method is illustrated. The example of other literatures is computed. By comparing the result, it is found that this algorithm illustrates its higher searching efficiency than genetic algorithm and particle swarm optimization algorithm of other literatures. Simulation results of the example demonstrate the effectiveness of this algorithm.
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Computer Engineering. 2009, 35(6): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2009.06.074Based on clustering assumption, this paper proposes a novel semi-supervised learning algorithm based on graph, named Density- sensitive Semi-supervised Clustering(DS-SC). The approach introduces a density-sensitive distance measure which reflects the clustering assumption well and fully exploits the competitive inherent structure information among dataset, and combining it with a graph-based semi-supervised learning methods leads to prominent clustering performance enhance of DS-SC. The results demonstrate the superiority of DS-SC in the application of a specific image in the further simulation.
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Computer Engineering. 2009, 35(6): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2009.06.075Test suite minimization aims at testing all the test objectives adequately with the least number of test suites. As abstracts each test case as independent node, this paper brings forward a new test suite minimization method based on ant colony algorithm and its detail steps by constructing virtual ant colony and updating heuristic information dynamically. Furthermore, this thesis validates the method by designing algorithm and doing emulate program. The experimental data proves that the method is effective and feasible.
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Computer Engineering. 2009, 35(6): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2009.06.076In order to use the Internet to complete the real-time control of remote equipment, this paper puts forward a tele-robotic system based on the embedded technology and tele-operation, which uses the S3C2410 as robot server, the reformative Linux as real-time operating system. It realizes bilateral communication between control command and feedback data of the master-slave robot, and enhances the performance of stability. The simulation experimental results demonstrate that the system is accurate and available.
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Computer Engineering. 2009, 35(6): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2009.06.077In allusion to the problem of coalition formation in dynamic open Multi-Agent System(MAS), a rule of coalition payoff distribution based on Agents’ abilities is proposed as well as the conception of coalition payoff ratio and other correlative propositions. The negotiation mechanism and negotiation rules among Agents are discussed. Based on these researches, a mechanism to form coalition based on Multi-Agent Genetic Algorithm(MAGA) is established. Simulation results show that this mechanism can reduce the quantity of system’s communications and guarantee the stability and global optimization of coalitions, which can improve the alignment efficiency of system.
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Computer Engineering. 2009, 35(6): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2009.06.078Adaptive interpolation of images presented by F. Arandiga uses Essentially Non-Oscillatory(ENO) schemes to interpolate close to an edge. The key idea of ENO schemes relies in the adaptive stencil which automatically selects the interpolating values in the locally smooth region. It can suppress the Gibbs oscillation effectively but still has several limits. To obtain higher accuracy, image zoom algorithm based on weighted ENO is proposed. The digitalization of an image involves an averaging process and it is appropriate to consider that the pixels of the image represent the cell average of a function. The idea is also an adaptive interpolatory procedure. And in smooth regions the linear average interpolation is used, while close to the edge the weighted ENO schemes are used to interpolate it. This weighted ENO scheme is constructed and has the same stencil nodes as the ENO but can have higher order accuracy. Experimental results demonstrate that the weighted ENO scheme can keep edges better than the ENO scheme.
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Computer Engineering. 2009, 35(6): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2009.06.079The Embedded Zero-tree Wavelets(EZW) algorithm transformation and the code can not be in progress at the same time, thus they can not realize in the complete significance sub-image coding, and this algorithm can not be carried out before the total graph alike wavelet transformation has not completed, and thus brings the problems as the algorithm is more complicated. In view of these questions, through the EZW algorithm’s thorough analysis, obtained from the algorithm transformation stage, an advanced EZW algorithm based on partition transform-merge filter is proposed. Experimental result proves that this advanced algorithm maintains the EZW algorithm principal advantage, can realize in the complete significance sub-image coding well, and simultaneously may have a lower computation complexity.
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Computer Engineering. 2009, 35(6): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2009.06.080In the contourlet transform, the image obtained by Laplacian Pyramid(LP) decomposition may produce artifacts on singularity of signal, which is harmful to image denoising. Due to the lack, a new LP decomposition is proposed and it can suppress the artifacts around the edge effectively. The new LP is used to implement the improved contourlet transform. Denoising experiments for Lena image using adaptive threshold show that denoising performance of the improved contourlet transform outperforms the contourlet transforms both in peak signal-to-noise ratio and visual quality.
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Computer Engineering. 2009, 35(6): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2009.06.081By analyzing the geometric features and visual characters of Q-style cartoon figures, an image-based method for computer simulation is proposed, which deforms the figures according to the figures’ photo and key parameters, and imitates the Q-style cartoon figures created by artists. The part-magnifying algorithm based on parspl spline curve is also put forward to solve the problem that the head of figures is out of shape, which enhances the visualization. This method needs little parameter, and is easy to control, fitting in the fields of animation and digital entertainment.
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Computer Engineering. 2009, 35(6): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2009.06.082Image inpainting is an important part of image processing. It is mainly used to restore the damaged image with some algorithms to attain to special goals, through the restoration of damaged painting with cracks and scratches to the removal or replacement of objects or word. This paper puts emphasis on comparing CDD model with fast inpainting model based on the Curvature Driven Diffusions(CDD). They all realize the connectivity and holistic principle, and have good ability for inpainting the large domain and minute edges, but the former inpainting speed is quite slow, the latter can overcome the shortcoming of slow speed. Experiment demonstrates this fast inpainting model can greatly advance the speed in inpainting, provided with the same quality of QCDD model.
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Computer Engineering. 2009, 35(6): 237-238. https://doi.org/10.3969/j.issn.1000-3428.2009.06.083The ARINC429, MIL-STD-1553B and CAN avionics bus interface communication system based on Field Programmable Gate Array(FPGA) are designed, which links different bus instruments. The hardware design, bus protocol module division and its internal structure are introduced. This design is programmed by VHDL language in QuartusII design platform, and is synthesized in the Synplify pro8.1 developing environment, which is the professional synthesize instrument. By downloading the design into FPGA chip, the reliability and veracity is verified.
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Computer Engineering. 2009, 35(6): 239-241. https://doi.org/10.3969/j.issn.1000-3428.2009.06.084According to the characteristics and the corresponding requirements of Controller Area Network(CAN), this paper proposes a novel Dynamic Scheduling Protocol(DSP), which dynamically selects the time slots of CAN bus for the real-life applications, and considers the mechanism to re-transmit real-time data. On basis of this, an algorithm of real-time DSP application based on CAN bus is introduced, which not only meets the real-time requirements of CAN applications, but also explores the bandwidth of CAN. Experimental results show this algorithm reduces the average response delay of the applications and improves the bandwidth utility of CAN networks.
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Computer Engineering. 2009, 35(6): 242-244. https://doi.org/10.3969/j.issn.1000-3428.2009.06.085Radar display terminal is used to display the radar information, and is an important component of different kind of radar system. The radar display and Direct3D are described, and on basis of which, a new simulation model and the implementation method of radar Plan Position Indicator(PPI) display with brightness based on VC++ and Direct3D are presented. This method is simple and easy to be grasped, and the module can easily be reused, expanded and transplanted. Experimental results show both the model and the method proposed are fit for project needs and have the certainly practical value.
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Computer Engineering. 2009, 35(6): 245-247. https://doi.org/10.3969/j.issn.1000-3428.2009.06.086Realization of visual simulation of maneuver target CCD tracking is valuable for military equipment training and tracking-algorithm design based on target image. This paper introduces steps to perform a visual simulation using the VRML-based virtual reality tool box of Matlab platform, and for the visual simulation of maneuver target CCD, aiming at the problems of the building-up of visual scene, the maneuver of 3D target and the visual CCD tracking, some solutions are accordingly presented with a simulation result.
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Computer Engineering. 2009, 35(6): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2009.06.087The stream processor is one of the representative for high performance processors. On the basis of analyzing the structure of Imagine stream processor, this paper implements the kernel procedure of a satellite orbit predicting system called CBPTRB. The performance of the cycle-accurate simulator based on ISim is tested, and the results of which is compared with the one getting from general x86 processor. According to the experimental results, the improved method is introduced.
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Computer Engineering. 2009, 35(6): 251-253. https://doi.org/10.3969/j.issn.1000-3428.2009.06.088Aiming at the problems existed in the process of medical information combination search, a search method for multi-information fusion based on medical ontology is proposed, which sets up ontology entity by using information extraction technique, and deals with the users’s query by using medical ontology. A prototype system based on this method is also implemented. Experimental results show this system can return multiple relevant information effectively, and show the importance of ontology in the field of multi-information fusion search.
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Computer Engineering. 2009, 35(6): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2009.06.089Network topology can be displayed on geography information map by introducing WebGIS to network management. This paper describes topology discovery methods, designs spatial data processing model and topology data model, and realizes network topology displaying system based on geography information map. This system uses Scalable Vector Graphics(SVG) documents to show the spatial data, and describes the true location of the resources in network. This system is a new tool for network management.
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Computer Engineering. 2009, 35(6): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2009.06.090This paper studies current grid technologies and search technologies, analyzes the advantages and disadvantages of parallel search engine and advances the solution scheme of parallel search engine based on grid which includes a three-tiered framework of application and a parallel search engine project of application. It realizes and deploys the MSE1.0 which is a parallel search engine based on grid according to this scheme, and obtains a better search results.
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Computer Engineering. 2009, 35(6): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2009.06.091This paper analyzes the problem of file system wear-leveling, and points out that the wear-leveling trigger condition will impact system I/O performance. Benchmark is performed on a latest flash file system——UBIFS, and the results show that system I/O performances vary by 20% under different trigger threshold. Aiming at the shortcoming of existing wear-leveling algorithm, it proposes an improved self-adapting algorithm.
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Computer Engineering. 2009, 35(6): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2009.06.092Public administration performance evaluation needs to adapt to the historical period and exterior environment of the governmental public administration, and its ultimate realization of the information requires that it is easy to configure, use and maintain the software for the user. In this paper, MVC framework increased from the MVC pattern is applied to design the public administration performance evaluation software framework. During this process, it emphasizes the adaptability and flexibility needs of the performance evaluation, and illustrates some related problems. It is a foundation of the following information work of the public administration performance evaluation.
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Computer Engineering. 2009, 35(6): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2009.06.093For the calligraphy and painting created by using of computer, only final results instead of creative process can be recorded and viewed. To solve the problem, this paper designs and implements a strokes recording and replaying system based on Gdiplus. This system can record the strokes’ shape, denseness and tempo while writing or painting, and then it can replay the whole process at will. By applying of texture blend technique, the system provides several painting tools to simulate charcoal, writing brush or other brushes. It defines a stocks recordings file format to save correlative parameters. Results show that the system applies to the teaching process, and provides a solution of preserving the creative process.
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Computer Engineering. 2009, 35(6): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2009.06.094Aiming at the strong capability of Blackfin processors on multimedia, this paper researches the techniques related to Graphic User Interface(GUI). It implements an embedded GUI system based on uClinux, which achieves smaller size and higher performance. It is suitable for electronic products requiring display of high definition. It compares the performance between the GUI with Microwindows. Results show that the development of embedded applications, especially multimedia products with high performance can benefit greatly from the implementation of the GUI.
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Computer Engineering. 2009, 35(6): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2009.06.095Search algorithm of the target list in the telecom supervise system is an important criterion of the system processing capability. SIP Uniform Resource Identifier(URI) is the identity of the SIP user in the network and it has its own characteristics. After analyzing the search performance of the Hash algorithm for the mass URIs, this paper puts forward an improved algorithm based on Bloom filter. The simulation results show that the search speed of the Bloom filter is almost the same as Hash algorithm, but the consumption of memory is reduced to 15 percentage of Hash after introducing finite and controllable false positive probability. So it can highly promote the processing capability of the system.
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Computer Engineering. 2009, 35(6): 275-276. https://doi.org/10.3969/j.issn.1000-3428.2009.06.096Aiming at solving the problems existing in media distribution storage policy of Media Distribution Network(MDN), and in order to advance system performance and satisfy more media requests of users, this paper introduces a new storage policy based on block. This policy divides every media into blocks and arranges all blocks due to its popularity regularly, to determine which media contents MS and PN need to store. In the result of simulating MDN system using NS2 simulate platform, this new storage policy can significantly improve the response time of user and the hit rate of local data.
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Computer Engineering. 2009, 35(6): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2009.06.097This research is based on WM algorithm and uses compress coding to work out a fast simple multi-pattern matching algorithm for foreign trade company to find out suppliers. It shows high performance on the tests and the practices, especially in the condition that the real-time data flow contents a mass of short key words.
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Computer Engineering. 2009, 35(6): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.06.098This paper proposes that technology of architecture for Struts, Hibernate and Spring(SSH) is available in the development and application of high education student management system which is based on B/S model, and presents the rapid procedure of design and development during the course of Web information system. Result proves that SSH not only can improve efficiency of system development and system maintainability but also can strengthen extensibility.
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Computer Engineering. 2009, 35(6): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2009.06.099The collaborative decision support system for armament demonstration is presented by analyzing and summarizing the disadvantage of armament demonstration that is active in the country. The system should be designed and developed based on the techniques of computer supported cooperative work and simulation based acquisition collaborative environment. The paper analyzes the functional requirement of system, builds the infrastructure of system, and designs the main functional modules that can satisfy the goal and aim of systemic function. The functional modules are designed and described by the method of tabulating the systemic functions and drawing the logic flow charts. The system is developed and realized.
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