05 December 2008, Volume 34 Issue 23
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Computer Engineering. 2008, 34(23): 1-3,19. https://doi.org/10.3969/j.issn.1000-3428.2008.23.001This paper presents a light weight virtual machine monitor——LVMM for improving the manageability and security of PCs. Compared with other virtual machine system, LVMM defines the active user domain which directly accesses the hardware devices except the physical disk and network devices. It accesses the virtual disk and virtual network card devices provided by the service domain. The user mode and experience of common PC users are kept unchanged while running several user domains on the LVMM platform simultaneously. The monitoring and access controlling of system resource in LVMM is independent of the user OS. Test result shows the prototype of the light weight virtual machine monitor has a little integral virtualization overhead.
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Computer Engineering. 2008, 34(23): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2008.23.002Based on the state of art on the application of the Supply Chain Simulation System (SCSS), a performance evaluation architecture is brought out. A comprehensive survey on the functionalities of current SCSS is summarized. It points out several important issues on performance improvements of SCSS based on the evaluations: the automated extraction and modeling of the mass input data, the simulation modeling technology on the combination of the domain knowledge and the stochastic business processes, automated generation of the datasheet and charts adaptive to different industrials, the intelligent design of simulation experiments, and the adaptive adjustment of model parameters.
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Computer Engineering. 2008, 34(23): 7-8. https://doi.org/10.3969/j.issn.1000-3428.2008.23.003This paper re-discusses TSK fuzzy systems modeling from a new perspective. A new TSK fuzzy system——CTSK is introduced. Compared with the traditional TSK fuzzy system, the CTSK fuzzy system has the following advantages: having a high interpretation, a better robustness, and a good approximation. Simulation results emonstrate the above advantages. And using the misty system of CTSK to evaluate the groundwater obtains the good result.
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Computer Engineering. 2008, 34(23): 9-10,1. https://doi.org/10.3969/j.issn.1000-3428.2008.23.004According to the problem of compromising emanation information caused by horizontal synchronous computer signal, this paper presents a correlative detection algorithm for extracting the information, and introduces a strategy of extracting synchronous information with Matlab simulation. The implementation of the algorithm on Digital Signal Processing(DSP) is given, and the experiment is performed on the ICETEK- C6713-A EVM platform, whose results prove the robustness of the method.
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Computer Engineering. 2008, 34(23): 11-13. https://doi.org/10.3969/j.issn.1000-3428.2008.23.005To address the problem of item cold-start in collaborative filtering systems, this paper advances a new method that using content based prediction before collaborative filtering to get the predictive ratings of items for users. It points out two fine grained parameters to guarantee the accuracy of the predictions. After the content based filtering, collaborative filtering algorithm is used to generate predictions for users. Experimental results show that the method is superior than traditional collaborative filtering algorithm in the coverage which indicates that the item cold-start problem is alleviated.
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Computer Engineering. 2008, 34(23): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2008.23.006Time series data is characterized as large in data size, high dimensionality and updates continuously. It is hard to manipulate for data analysis and mining in its original structure. Defining a more effective and efficient time series segmentation algorithm is of fundamental importance. This paper proposes a time series segmentation algorithm based on Series Importance Point (SIP), which can approximately represent time series by linear composed of SIP. This method adopts SIP as segmentation point in time series reflecting mostly character of time series. The dimensionality of time series is reduced, and the error of the whole is least.
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Computer Engineering. 2008, 34(23): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2008.23.007This paper presents Adaptive Particle Swarm Optimization(APSO) algorithm to solve the precocious convergence problem of Particle Swarm Optimization(PSO) algorithm. The notion of species is introduced into population diversity measure. Inertia weight is nonlinearly adjusted by using population diversity information. Velocity mutation factor and position crossover factor are both introduced and the global performance is improved. The algorithm is applied in reactive power optimization. Simulation results of the standard IEEE-30-bus power system indicate that active power losses are reduced form 5.988 MW to 4.889 MW(18.36% reduction) and APSO is superior to current methods for finding the best solution, in terms of both solution quality and algorithm robustness.
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Computer Engineering. 2008, 34(23): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2008.23.008This paper proposes an algorithm based on Contourlet characteristic modification, which extracts the characteristics in different resolution with different methods, adjusts them by statistical analysis, and deals with the feature vectors by Support Vector Machines(SVM). Compared with the existing transforms including Ridgelet, Wavelet and Wavelet package, the method consistently yields the best overall performance in recognition veracity rate, especially when the images are interfered by intensive noise.
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Computer Engineering. 2008, 34(23): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2008.23.009A visual security assessment method is presented. Video quality assessment and visual security assessment are compared. Method of structural distortion is introduced from the theory of structural similarity. Cryptograph images of encrypted video sequences are analyzed by using its structural distortion value. Visual security is assessed with objective methods and algorithms. Simulation results show that this approach provides objective assessment, effective speed and good performance at the same time.
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Computer Engineering. 2008, 34(23): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2008.23.010According to the disadvantages of the method based on character string matching, the method based on comprehension and the method based on statistic, this paper presents a word segmentation method based on ontology and syntax analysis, which avoids the disadvantages about the lost of the semantic meaning with traditional method. It analyzes the grammar by building ontology, and inquires based on the intelligence. Experimental result proves that the accuracy is improved.
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Computer Engineering. 2008, 34(23): 29-30,4. https://doi.org/10.3969/j.issn.1000-3428.2008.23.011In-Tree task graph can be used to represent a lot of issues of divide-and-conquer algorithms such as merge, summation, etc. Aiming at In-Tree task graph, a level scheduling algorithm is proposed. The algorithm stores scheduled tasks by using queues. In the same layer of scheduling, the task whose precursor is not null is prior scheduled to one of its precursor processors. Only tasks with null precursors are considered to be allocated a new processor. Experiment shows that compared with the former algorithms, the algorithm uses fewer processors in the case of approximate same length of scheduling.
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Computer Engineering. 2008, 34(23): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2008.23.012This paper analyzes some classical algorithm of association rule mining, and gives a high efficient algorithm based on Matrix. The method puts the database changing 0-1 matrix and needs only one pass over database, uses logical operation to discover frequent itemsets calculates it is support, accelerates the verification speed of the frequent k-item sets, reduces I/O overheads greatly and the store space. Test result shows that the performance efficiency of new algorithm is obviously better than Apriori algorithm.
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Computer Engineering. 2008, 34(23): 34-35,4. https://doi.org/10.3969/j.issn.1000-3428.2008.23.013The paper designs and implements interactive data mining framework based on therapeutic evaluation of childrens’ pneumonia. Combining data mining, mathematical statistic with logic analysis framework, the discovery the associations between zheng with symptoms by retrospective analysis and forward looking study. The paper not only breaks through the limitation of traditional therapeutic evaluation method, but also optimizes therapeutic criteria by building the objective, interactive, metrizable therapeutic evaluation system.
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Computer Engineering. 2008, 34(23): 36-37,7. https://doi.org/10.3969/j.issn.1000-3428.2008.23.014After the research of existing emulator, it shows that the emulator for the hardware of self-service equipment is difficult to find. In view of the problem. This paper proposes an solution by software simulating. A simulation system based on Protopas is designed and implemented. The system makes application developer avoid the complex operation on the hardware. As a result, it can make the development work of ATMC application projects more effective, and it can also reduces the cost of software development greatly.
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Computer Engineering. 2008, 34(23): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2008.23.015Traditional migrating workflow systems make procedural specifications drive their instances to work, which greatly weakens the agility of instances. To solve this problem, a conception of target-oriented migrationg workflow and its conceptual model are proposed in this paper. It proposes a mechanism based on the BDI-architecture. The migrating instances can generate beliefs, desires, intentions and actions to lead the workflow state to the ultimate purpose. Compared with the traditional workflow methods, the model is flexible and intelligent. It is target-driven and capable of dealing with changes and making decisions according to the workflow state.
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Computer Engineering. 2008, 34(23): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2008.23.016This paper analyzes the disadvantages of current popular database connection pool, and puts forward a new solution of self-adaptive database connection pool according to the requirements of Non motor-Vehicle Management System(NVMS). The solution can dynamically adjust Extensible Markup Language(XML) configuration parameters based on application scope, set up thread of monitoring to determine the corresponding management strategies, and realize the self-optimization of connection pool. Comparison test shows that the solution manages connection resources more effectively and improves the whole performances of system.
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Computer Engineering. 2008, 34(23): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2008.23.017This paper analyzes disadvantages of the current policy languages and the policy components. The ECA triple are extracted. Their relationships are analyzed, and a policy description language based on ECA is designed. The language is simple and practical, which overcomes all of the shortcomings of the existent policy languages, and unifies the policy specification of all kinds of network security devices in the large-scale distributed environment.
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Computer Engineering. 2008, 34(23): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2008.23.018TRAP/J is a structure which can add adaptive capacity into original existed application(without modification of source code and virtual machine). This paper proposes a new architecture of adaptive Java program. Wrapper class and AspectJ are applied to enclose and replace original class, and abstract class is applied to represent original class. Experiments show that compared with TRAP/J, the running speed of program with new architecture is higher within single computer, but within networks there is no remarkable difference between two architectures.
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Computer Engineering. 2008, 34(23): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2008.23.019A parallel program should be deadlock-free to assure correct, but most of researches are focused on deadlock detection while few on deadlock prevention. Based on the classification of communication procedures of message-passing parallel programs, they are modeled by Petri nets, and the correspondence between program’s deadlock and Petri net’s dead marking is given. Two kinds of reason leading to deadlock are analyzed and an algorithm is provided to detect the deadlock, and three methods of deadlock prevention are presented with comparison to achieve the best one. The given method not only is useful for all message-passing parallel programs, but also can improve the programming efficiency with pre-verification.
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Computer Engineering. 2008, 34(23): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2008.23.020In order to take fine-grained and transparent access control for dynamic Web pages resource, this paper defines “fragment”, presents an approach of fragment-level access control for Web pages resources based on data stream analysis, which analyses the relation between request and response fragments, and designs and realizes two kinds of arithmetic for fragment identify. Experimental results demonstrate the approach can identify dynamic Web pages resource and take fine-grained access control.
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Computer Engineering. 2008, 34(23): 56-58,8. https://doi.org/10.3969/j.issn.1000-3428.2008.23.021Business rules certainly are not static state. They frequently change, and their connection rule also can change with it. As a result of these changes, it is necessary to maintain the flexibility when the business process is realized and modified. If system in view of the traditional programming method is used to constitute the business rule, when the enterprise needs to change the rule, the system must carry on the procedure code massively change. Based on the Spring framework, this paper designs and realizes one of the Spring rule engine technology, which can effectively realize the code and the service rule separates, and guarantee business rule change flexibility.
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Computer Engineering. 2008, 34(23): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2008.23.022The HACCP data of food shows diversity shapes, its classification results on the accuracy and professionalism. The existed algorithms have been difficult to meet it. Based on the classic BIRCH algorithm, and the existed two algorithms multi-threshold and multi-representation points CF tree, a new multi-threshold and multi-representation BIRCH algorithm is designed, and the professional knowledge of the classification is added to guide set different variable thresholds to every representation points. Thus, the new algorithm can meet diversity data shapes, reduce the times of reconstruction of the CF tree, and improve the efficiency of the algorithm.
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Computer Engineering. 2008, 34(23): 62-64,6. https://doi.org/10.3969/j.issn.1000-3428.2008.23.023Sentences similarity arithmetic is the key of Frequency Asked Question(FAQ). There are many muti-sense words in Chinese. This paper proposes a new arithmetic of word sense distinguish based on HowNet, uses the advanced method to the sentences similarity and realizes a real FAQ system. Word sense distinguish uses the proposed method to do the word sense distinguish. The sentences similarity is got with HowNet, and a real FAQ system is realized. Experimental results show that the proposed method can effectively increase the accuracy of the FAQ system.
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Computer Engineering. 2008, 34(23): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2008.23.024With the limited functionality of data automatic collection in Excel, this paper suggests a way to automatically separate data in Excel reports and discusses engine. This engine uses two layer mapping (template maps to template structure tree, and template structure tree maps to XML schema). XML schema and the mapping path of each cell are generated automatically from Excel template. The related XML document which is in accord with template is automatically separated from Excel report data by the Excel data separation mechanism and it will be much easier to collect data from Excel report and be more advantageous to system’s expansion and integration.
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Computer Engineering. 2008, 34(23): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2008.23.025Aiming at complex calculation method and massive data in some science research field, a Globus-based computing grid is designed and implemented, which can discover available nodes and submit computing jobs dynamically. Also, Globus Toolkit 2 provides API functions to construct grid environment and grid application, so the parallel computing efficiency is remarkably enhanced. Through running a typical parallel algorithm, the availability and high efficiency are verified, and a result analysis is given briefly.
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Computer Engineering. 2008, 34(23): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2008.23.026Unified RTI interfaces, designed with extensive compatibility and scalability in mind, are proposed to solve the interoperability problem of the heterogeneous simulation federates. This paper briefly introduces the distributed objects middleware and the Interface Definition Language(IDL), on which the distributed objects model and abstract interface of the RTI are based. How to use unified RTI interfaces to integrate simulation federates in different languages or different protocols and how to expand it in the hierarchical RTI are discussed.
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Computer Engineering. 2008, 34(23): 74-75,8. https://doi.org/10.3969/j.issn.1000-3428.2008.23.027In order to meet catalog administration of Extensible Markup Language(XML) in P2P, this paper proposes an index method Advanced Prime Number Index(APNI), which uses the prime number index method and improves it with accessorial structures of Prime Number Index table and hierarchy index table. The purpose is that it queries XML more flexibly. Results of the experience show that it queries XML using APNI more quickly than using Prime Number Index.
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Computer Engineering. 2008, 34(23): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2008.23.028Today scientific applications on distributed computing environment have huge data transfer which continues to increase drastically every year. This implies a major necessity to move huge amounts of data from original data site to target site on the whole computation cycle, which brings with it the problem of efficient and reliable data placement. The current approach to solve this problem of data placement is either doing it manually, or employing simple scripts which do not have any automation or fault tolerance capabilities. The goal is to make data placement activities robust and efficient. It will be queued, scheduled, monitored, managed, and even check-pointed. The data placement activities should be treated differently from computational jobs, since they may have different semantics and different characteristics. The method for data placement is tested.
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Computer Engineering. 2008, 34(23): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2008.23.029In the development process of Next Generation Network(NGN) service, service provider needs to communicate with various heterogeneous database belonging to telecom operators, so it is required imminently to design and implement a heterogeneous database middleware. It adopts layer-framework and multithreading method, queues and schedules data access request uniformly, therefore it improves the security, flexibility and expansibility on data access, and now this middleware is extensively applied to on-line NGN service system.
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Computer Engineering. 2008, 34(23): 82-83,1. https://doi.org/10.3969/j.issn.1000-3428.2008.23.030On the running process of Next Generation Network(NGN) service, large numbers of calls exist at the same time, so it requires high real-time data access. In order to solve this question, an ideal about memory database is put forward. It saves the service data to memory by a two-layer hash table uniformly, and it is implemented that how to load, synchronize and access data of memory database. Now the memory database is applied to on-lined NGN service successfully, and the reliability and security is verified practically.
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Computer Engineering. 2008, 34(23): 84-85,9. https://doi.org/10.3969/j.issn.1000-3428.2008.23.031The main memory usage with low efficiency is key factor to downgrade Java program performance. Three cases including leaked objects, instantaneous objects and idle objects are analyzed, which downgrade Java programs performance. How to solve these problems is also discussed. Moreover, the constructing the object lifecycle behavior model is proposed. Experimental results show this scheme is effective.
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Computer Engineering. 2008, 34(23): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2008.23.032According to the fact that few density-based clustering algorithm can automatically process the data with non-uniform density, an auto-clustering algorithm based on non-uniform density is proposed. This algorithm has all the merits of the existed density-based clustering algorithm and can deal with the date effectively. Experimental results show its efficiency.
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Computer Engineering. 2008, 34(23): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2008.23.033Aiming at the particularity of text genre classification in feature selection and weight calculation, this paper presents the text content category information, which improves the conventional CHI feature selection method and the tf.idf formula of feature weight. By using Support Vector Machine(SVM), an automatic classification on a Chinese text corpus consisting of five genres is carried out. Experimental results show this scheme is feasible.
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Computer Engineering. 2008, 34(23): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2008.23.034This paper introduces the composition and architecture of AFDX system, puts forward a highly reliable redundancy management mechanism along with corresponding processing algorithm of redundant frames through analysis and study of the original AFDX real-time communication protocol. Based on timed automata theory and UPPAAL simulation, it is proved that ADFX can meet the reliability requirement on avionics data transmission.
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Computer Engineering. 2008, 34(23): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2008.23.035The performance of the whole Wireless Sensor Network(WSN) is determined by the communication module on WSN node. Based on practical demands, This paper uses CC1100 chip that featuring low current consumption as wireless transceiver unit while fulfilling the basic functions. It analyzes the characteristics of CC1100, introduces embedded operating system TinyOS, and expatiates how to use NesC to implement CC1100 driver based on MSP430F1611 platform.
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Computer Engineering. 2008, 34(23): 98-101,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.036In clustered Wireless Sensor Networks(WSN), when cluster headers send data to sink node in multi-hop communication mode, the nearer to the sink node, the more routing data will be put on the headers. As a result, headers near the sink node will quickly lose their energy and lead to network-partitioning. Considering this problem, this paper proposes an unequal scaled energy-efficient clustering routing algorithm. In areas nearer to the sink node, more less scaled clusters is formed by limiting the cluster radius. At the same time, a gradient of hops of clusters from the sink node is formed. Data travels through least number of clusters before they get to sink node. It balances the loading among clusters by dynamically changing data’s next routing cluster. According to the simulation results, this algorithm can prolong the network’s lifetime and save the network’s energy.
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Computer Engineering. 2008, 34(23): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2008.23.037This paper studies the influence of multi-VM and multi-CPU for expansibility of XEN VM network full-virtualization mechanism. Experimental results show that when the VM increases or the amount of CPU goes beyond the limit, the network performance will be decreased. It analyzes the key factors’ influence on the expansibility, that is schedule mechanism and event channel mechanism.
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Computer Engineering. 2008, 34(23): 105-106,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.038Aiming at limited communication distance of Wireless Sensor Network(WSN), a remote monitoring system of WSN using GSM network to transmit short message is designed. After introducing system architecture and working principle, a detailed description of hardware design and software implementation is presented. This system has several advantages, such as simple realization, low communication costs, large capability and high reliability. The experimental results indicate that the system can provide good stability, and realize remote monitoring to monitor area.
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Computer Engineering. 2008, 34(23): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2008.23.039A wireless sensor network node with acoustic self-localization technology is introduced. The node can obtain the real-time orientation and distance information of the object node. Cross array time-delay estimation method is adopted to measure the orientation and TDOA mechanism is used to measure the distance. Test shows the system power supply in idle state is less than 20 μA, distance error is less than 3%, and angle error decreases with the sampling rate or array range increasing in the 15 m range.
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Computer Engineering. 2008, 34(23): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2008.23.040Multi-path routing is an important algorithm for wireless Ad Hoc network because it can increase the throughput of flows from the source node to the destination node. This paper discusses the throughput in wireless Ad Hoc network with multi-path routing. Simulation results show that when the distance between the source node and the destination node is long enough, the throughput of flow through multi-path is more than that with shortest single-path.
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Computer Engineering. 2008, 34(23): 113-115,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.041This paper proposes a distributed register message forwarding way to cope with the problem when Designated Router(DR) send register message to Rendezvous Point(PR), which may result in too many register packets on the controller plane of the router. Theoretical analysis and simulated data results show that the method lightens the controller plane’s execution load dramatically, shortens the equal execution time of multicast packets in the router, and reduces the interactive time between controller plane and data plane.
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Computer Engineering. 2008, 34(23): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2008.23.042In order to improve network efficiency and packets processing speed, under the same preferences of network topology, seven different active queue management algorithms of different network traffic are simulated on the base of the NS2, which are implemented on the bottleneck link. By analyzing trace file and calculating every QoS parameter, the best queue management algorithm is advanced and the system is realized on network processor¬¬——IXP2400. The performance of QoS has achieved optimization for FTP traffic in SRED algorithm, CBR traffic in BLUE algorithm, HTTP traffic in FRED algorithm.
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Computer Engineering. 2008, 34(23): 119-122. https://doi.org/10.3969/j.issn.1000-3428.2008.23.043This paper proposes a reliable data transport algorithm for cluster structure in Wireless Sensor Network(WSN). It includes: the choice of reliable routing and candidate routing considering residual node energy, buffer usability and channel error ratio, the detection of pre-congestion according to the spare space of a node buffer and the following catabatic methods, category handling the failure of cluster node or others. Simulation result shows that the algorithm improves the reliability of data transport.
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Computer Engineering. 2008, 34(23): 123-124,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.044Voice over Internet Protocol(VoIP) service quality is mainle affected by the packet lost problem. Turbo codes can support the reliability in data transitions, but the real-time requirement can not be satisfied. Base on the low performance of Turbo code on network transmission, the paper brings forward a method to improve its performance, including reducing the iteration time when decoding and adaptively setting the interleaver size. Experimental results prove that the advanced Turbo code can be better applied to VoIP.
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Computer Engineering. 2008, 34(23): 125-127,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.045This paper improves dynamic global optimal scheme according to problem of load balance in distributed systems, and proposes a new scheme which is combined with dynamic scheme and static scheme. When the system is in high communication overhead, the new scheme overcomes the disadvantage of dynamic load balance scheme and enhances the comprehensive properties of system effectively.
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Computer Engineering. 2008, 34(23): 128-129,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.046This paper discusses a new method based on the Empirical Mode Decomposition(EMD) algorithm to estimate the Hurst index that is an important statistical parameter of self-similar network traffic. The algorithm can adaptively decompose self-similar traffic into a series of Intrinsic Mode Function(IMF). By using the relationship between the energy of IMFs and the Hurst index, it can adaptively estimate the Hurst parameter of self-similar traffic. Experimental results show that this algorithm can adaptively estimate the Hurst index of self-similar traffic.
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Computer Engineering. 2008, 34(23): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2008.23.047As to increase of load in Wireless Sensor Network(WSN) leading to performance of network bad quickly, a scheme based on proportion distribution information flow scheduling module for WSN is brought forward. Congestion in WSN can be prevented by introducing a method which distributes flow into congestion nodes by distributing information cost to former hop nodes of congestion nodes according to some proportion. Result turns out that this method not only controls flow rate into congestion nodes, but also avoids serious congestion in former hop nodes.
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Computer Engineering. 2008, 34(23): 133-135,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.048Based on the measuring data collected on experimental network, this paper analyzes the effect of background traffic, server CPU load and file size upon the performance of FTP protocol. The results show that bandwidth and background traffic fundamentally constraint on FTP performance, CPU load impacts FTP performance only when it is relative heavy, and file size may affect FTP performance since it is related to the occupied network and server resource.
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Computer Engineering. 2008, 34(23): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2008.23.049Pure P2P network takes on the characteristics of Small World phenomena. This paper deals with the mechanicsm and principles of P2P Web page search engine, arrives at with the technique of duplicate Web pages removing and page ranking based on Small World phenomena, and analyzes the methods on the basis of simulation experiment. The outcome indicates that external duplicate removing and external ranking with Small World phenomena can effectively balances processing workload, waiting time and the pointless network bandwidth consumption.
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Computer Engineering. 2008, 34(23): 139-141,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.050Based on Alzoubi and Wan’s algorithm, this paper proposes Effective Distributed Minimum Connected Dominating Set Algorithm (EDMCDS) by choosing connector node with two hop local network topology information. Analysis shows that the size of connected dominating set with EDMCDS is (5.8+ln4)opt+1.2, time complexity is and message complexity is , which are all better than TFA algorithm and Alzoubi and Wan’s algorithm.
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Computer Engineering. 2008, 34(23): 142-143,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.051To choose and design effective network I/O model is the key point to improve the performance of Web server. By analyzing several network I/O models in Lunix system, three methods to improve the performance of these network I/O models are proposed. How to implement these methods is also discussed. Experimental results show its efficiency.
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Computer Engineering. 2008, 34(23): 144-146. https://doi.org/10.3969/j.issn.1000-3428.2008.23.052Aiming at traditional LSB steganography weakness this paper points that it can be detectable by statistical analysis such as RS and Chi-square analyses. It proposes a novel LSB image steganography algorithm that can effectively resist image steganalysis based on statistical analysis after analysising the feature of LSB steganography and statistical analysis. Experimental results show that the proposed method can effectively resist steganalysis based on these two steganalysis.
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Computer Engineering. 2008, 34(23): 147-149,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.053This paper presents an improved digital signature scheme based on elliptic curve. The security and complexity of digital signature is analyzed. This proposed scheme not only can efficiently resist birthday attack, but also can improve the security of digital signature. In addition, proxy digital signature scheme with its security analysis is proposed. The two message recovery schemes may easily realize with low computation. The paper examines the two schemes by means of examples.
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Computer Engineering. 2008, 34(23): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2008.23.054After researching the theory of the Color Petri Net(CPN) and Aiming at the problem in intrusion detection, which is named “alert tire”, a CPN attack template, which is separated by the authority that can be gained by the invader, is built in this paper. The complete process of multi-step attack is presented, according to correlate the lowly, disperse alert information in order. Limited template is used in the methods of alert correlation, and the method is simpler and easier to realize than before. Security personnel can predict and appraise the security condition of the network in the angle, which is the authority that can be gained by the invader.
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Computer Engineering. 2008, 34(23): 153-154,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.055This paper proposes a collaborative-based spam filtering scheme to overcome the quality evaluation problem existed in current spam filtering techniques. The scheme can be used to solve the problems with current techniques in classifying Email attachments. Because spam senders often resort to mass mailing, the system improves filtering accuracy by considering the factors that include user actions and reading speed as well as feedbacks from others on the same mailing list. The collaborative-based spam filtering is implemented as part of a hybrid spam filtering system. Experimental results show that the scheme significantly reduces the recall rate.
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Computer Engineering. 2008, 34(23): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2008.23.056This paper presents a Web services security test framework, it can effectively promote the normative of test processes and enhance test effect. It investigates the main security function requirements and implementation standards for Web services and the principals of implementing security functional test. A message level security functional test tool is implemented which can generate security test cases automatically. Experiments show that the tool is applicable and effective.
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Computer Engineering. 2008, 34(23): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2008.23.057After researching a variety of attack graphs generation methods, this paper proposes a related algorithm based on privilege escalation, and designs an effective tool to generate attack graphs. This tool describes network attack model in database language, which including 3 attributes that is host description, network connectivity and exploit rule, and stores network configurations and host information into database automatically. Attack affair graph is generated according to the dependency algorithm that integrates the breadth-first forward exploration and the backward. The attack graph can achieve the whole analysis of network security.
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Computer Engineering. 2008, 34(23): 164-166,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.059Risk assessment is an effective approach to evaluate security state of information systems. A model of information security risk assessment system based on immune network both with a quantitative evaluation theory are presented. This model can reflect the relationship of the evaluation factors. It has the features of self-learning, self-update and real-time detecting. Experiment shows the model is effective to assess the risk of information systems.
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Computer Engineering. 2008, 34(23): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2008.23.060This paper analyzes the Online Certificate Status Protocol(OCSP), and some limitations of the protocol are found. It improves the normal protocol: the improved OCSP response includes basic OCSP response and type-A OCSP response. The improved responder adopts signature in advance technology to improve efficiently the functionality based on the improved protocol. The responder resists the replay attack efficiently. It analyzes the efficiency and security of the improved OCSP responder. Experimental result shows that the average response time of the improved responder is reduced by 27%, and the response speed is improved.
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Computer Engineering. 2008, 34(23): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2008.23.061With the problems of secreat leak and unrealized shared verification in Tzeng’s paper and Hsu’s, an improved scheme is proposed, by increasing signature and verification secret polynomials’ degree. This scheme can resist conspiracy attack effectively and actualize shared verification, as it has been justified using Lagrange interpolation and interrelated knowledge.
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Computer Engineering. 2008, 34(23): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2008.23.062This paper uses chaos anti-control idea to generate a hyper-chaotic system, and uses the pseudo-random feature of hyper-chaotic system to design a stream cipher. The nonlinear state feedback is added to a Discrete Linear Time Invariant(DLTI) system and the hyper-chaotic system is constructed. The existence of feedback gain matrix is proved and the constraint condition between and coefficient matrix is given. A stream cipher algorithm based on a 3D hyper-chaotic system is designed. Simulation results indicate that the stream cipher has favorable statistic characteristics.
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Computer Engineering. 2008, 34(23): 176-177,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.063An improved PrefixSpan algorithm based on time constraints and attribute-relative is developed to fit into the network audit data of computer intrusion detection. The algorithm applies the triangular matrix M to reduce the number of projected databases and the Apriori checking to reduce the size of projected databases. It enhances effectiveness and usefulness of sequential patterns mining. The experiment of dealing with a computer network audit database gives the application and result analysis of the algorithm.
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Computer Engineering. 2008, 34(23): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2008.23.064Combining with the principles of the produce to buffer overflow attack, this paper analyzes the structure of buffer overflow attack codes, and describes the Snort rules used for buffer overflow attack inspection. It constructs a state-graph-based analysis model of buffer overflow attack, which has theoretical and practical meaning to buffer overflow attack analysis and prevention.
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Computer Engineering. 2008, 34(23): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2008.23.065Aiming at the problems of key management in publish/subscribe system, this paper presents a key management method independent of subscriber group. An encryption key with an event and an authorization key with a subscription filter are combined in the method, and hierarchical key derivation algorithm is used to map the authorization keys and the encryption keys into a common key space in order to make the cost independent of the number of subscribers. Experimental results show that the cost is less and the scalability is better than traditional solution.
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Computer Engineering. 2008, 34(23): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2008.23.066A new digital CDMA watermarking algorithm based on orthogonal wavelet basis is proposed in this paper. Harr wavelet basis is changed into a multilevel orthogonal sequence by scaling and translation, which is used to encode the binary image. Then the CDMA encoded watermark is adaptively embedded into the third level detail sub-images of DWT domain. Theoretical analysis and experimental results show that the capacity of the hidden information is raised and the security is enhanced. Compared with Hadamard sequence and improved gold sequence in the simulation, the multilevel sequence performs better than binary sequence in attack-resistance.
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Computer Engineering. 2008, 34(23): 187-189,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.067The Agent organization is a kind of flexible and effective problem-solving mechanism for MAS. In view of the present situation that Agent organization model is based on egoistic Agent, a mission-based Agent organization model is proposed, which can be used in governmental or military agencies. The model is based on altruistic Agent and utilizes trust valuation as well as the utility of Agent organization to evaluate the Agent’s ability to solve problems. Furthermore, the mission characteristics, organizational formation and evolution mechanism of Agent organization are researched from the perspective of thinking properties of Agent as well as their interrelations. This model can improve the efficiency of solving problems and enhance the stability of Agent organization. Thus it will widen the view of research on Agent organization.
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Computer Engineering. 2008, 34(23): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2008.23.068An effective algorithm for array targets recognition in remote sensing images is proposed. It not only utilizes spatial features, but also extracts Gabor texture as non-spatial features for feature clustering. An iterative analogous array targets extraction process is used based on graph cuting theory, aiming at locating the targets array. Experiments show that by adding the non-spatial features and using the iterative analogous array targets extraction process, the proposed algorithm is able to eliminate a large number of false alarms and locate the array target accurately.
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Computer Engineering. 2008, 34(23): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2008.23.069Aiming at the disadvantage of classical rough set theory on identifying the conceptually similar terms and the relationships between classes, this paper proposes a novel information retrieval model based on conditional probability relation and rough set. Conception space is formed by defining conditional probability relation in index words space to mine conception similar class automatically. A method is designed to calculate semantic distance between a document and a query, as well as documents. And the ordered outputs of retrieval result are acquired. The simulation instance shows that this algorithm is feasible and effective in practice.
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Computer Engineering. 2008, 34(23): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2008.23.070This paper introduces the principle and efficiency of the Apriori algorithm which is the classical algorithm of association rules mining, and proposes an improved Apriori algorithm――En-Apriori algorithm which is aimed at the disadvantage of Apriori algorithm. This algorithm adopts a matrix method and need scan the database only once and optimizes the join operation, so it is more efficient. The experiment shows that the En-Apriori algorithm outperforms Apriori algorithm, and gets a good practicality.
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Computer Engineering. 2008, 34(23): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2008.23.071A method of Artificial Immune Network based neural network ENsemble(AINEN) is proposed. After initialing a network ensemble with Bagging, the artificial immune network is applied to the neural network ensemble which looks like an independent neural network in the microscopic view and an artificial immune network in the macroscopic view. Then the heterogeneity at microscopic level, and the fitness at macroscopic level is increased. As a result, the generalization error is decreased. The comparison of the results of AINEN and GASEN shows that the AINEN is more efficient than the GASEN.
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Computer Engineering. 2008, 34(23): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2008.23.072Image matching with fast speed and high accuracy lay the foundation of successful defect detection system for printed matter. An improved Harris corner detection method is proposed and testified by a stability evaluation criterion, where the proposed detector is found to perform well in industrial environment. An affine transform model is established to approximate the geometrical changes between two windows of corresponding feature. The parameters of the model are computed by deterministic annealing to avoid time-consuming exhaustive searches. The fundamental matrix and homography matrix are estimated robustly with RANSAC algorithm, then epipolar and homography constrains are used to delete the wrong correspondence of initial matching. The algorithm with fast speed has been successfully utilized in the on-line defect detecting system for printed matter.
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Computer Engineering. 2008, 34(23): 205-207,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.073A novel algorithm for moving objects detection based on pixel classification is proposed. This algorithm preprocesses the images with illuminate standard in order to decline detection mistakes caused by illuminant changes. The pixels are classified by its characteristics into the single-model and the multi-model. The former uses median method for background modeling while the later uses GMM. The experiments show that this algorithm, compared with GMM, is computational efficient and can be used for real-time systems easily.
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Computer Engineering. 2008, 34(23): 208-209,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.074In order to configure the Radial Basis Function(RBF) neural network model, an automatic searching algorithm based on Particle Swarm Optimization(PSO) is proposed with the thesis of phase space reconstruction. This algorithm is compared with other similar algorithms with respect to Logistic mapping and underwater acoustic signal. Experimental results show this algorithm has better performance in terms of training accuracy and convergence rate, and also supports the modeling, prediction and dynamic analysis of underwater acoustic signals.
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Computer Engineering. 2008, 34(23): 210-213. https://doi.org/10.3969/j.issn.1000-3428.2008.23.075Two new decoding methods for Gene Expression Programming(GEP) are proposed in this paper, and their time and space complexity are analyzed. The first method conforms to the mapping relationship between genotype and phenotype of GEP, and the expression and its value are obtained directly on genotype. The second method gets the expression and its value by stack, which makes the mapping relationship between genotype and phenotype different from the foregoing. The two methods have different effects on the recombination operators. The experiments on three groups of data show the new decoding methods are feasible and efficient. The second method is more propitious to preserve the excellent schemes.
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Computer Engineering. 2008, 34(23): 214-216,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.076This paper dedicates to use the intelligent aircraft tractor’s monocular vision to detect the real-time relative position of the tractor and aircraft’s front wheel, and to realize the towbarless tractor auto connects the aircraft’s front wheel. On the basis of researching basic geometry theory, this paper establishes an approximate geometry model of the aircraft’s tire. Through analysis of the approximate geometry model, it presents an algorithm which uses the image of aircraft’s tire to detect the relative angle of the tractor and aircraft’s front wheel. Using the mapping relation of the image plane and ground plane, it presents an algorithm to detect the setover between the tractor’s midline and aircraft’s front wheel. And the simulation result proves that the localization algorithm can get much more accurate data and provide satisfied lateral control parameters for the intelligent towbarless aircraft tractor.
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Computer Engineering. 2008, 34(23): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2008.23.077This paper proves that the universal steganalysis is a difficult two-class recognition problem, of which the between-class distribution is quite close and the within-class distribution is very scattered. This paper proposes the high-dimension feature based on the two Markov models of inner-block and inter-blocks in DCT domain of JPEG image. The paper also proposes two types of classifiers for high-dimension classification. One is the improved Bayesian classifier, and the other is the Class-wise Non-Principal Components Analysis(CNPCA)classifier. The latter is simple and slightly lower performance, but is still superior to SVM classifier. Experiments are taken out in CorelDraw image database, and the result shows that the scheme outperforms the existing steganalysis technique in attacking modern JPEG steganographic schemes F5, Outguess, MB1 and MB2.
【Key words】steganalysis; JPEG image; DCT coefficient; Markov model; improved Bayesian classifier; Class-wise Non-Principal Components -
Computer Engineering. 2008, 34(23): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2008.23.079Aiming at the fact that the Population Migration Algorithm(PMA) has stronger global searching ablility and stability, an improved heuristic ordered crossover operator based on ordered crossover operator is proposed, which is introduced into the process of Population Migration. Simulation experimental results show this improved algorithm can solve TSP efficiently, and has fast convergence characters.
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Computer Engineering. 2008, 34(23): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2008.23.080Aiming at the problem of lower recognition rate and longer recognition time for license plate character when the license plate image quality degenerates, a license plate character recognition method based on quantum neural computation is proposed. This method implements quantum neural computation by making universal quantum gate as neural network’s activation function, and chooses the rough grid feature of the plate as the character recognition feature to conduct license plate character recognition. Experimental results show this method can improve noisy license plate recognition rate and anti-interference ability effectively.
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Computer Engineering. 2008, 34(23): 230-231. https://doi.org/10.3969/j.issn.1000-3428.2008.23.081According to the application demand of remote surveillance system based on PSTN, the paper puts forward a rate control strategy of very low bandwidth. The strategy presents the rate control arithmetic of I frame and introduces quadratic rate distortion mode. It improves rate control arithmetic of P frame, which solves the problem of the rate control used at very low bandwidth preferably. The results of experiment show that the arithmetic reduces the delay of encoder buffer greatly, and improves the quality of reconstructed images clearly at the same time.
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Computer Engineering. 2008, 34(23): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2008.23.082According to the problems such as bad broadcasting quality of Video-On-Demand(VOD) operation, a mixed VOD model fitting for embedded terminals is proposed in terms of Quality of Service(QoS) protection, delay control and data download strategy. The scheme to implement this model is also presented. Experimental results show this scheme is effective.
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Computer Engineering. 2008, 34(23): 235-236. https://doi.org/10.3969/j.issn.1000-3428.2008.23.083This paper introduces the systematic structure and client software design and realization of the video surveillance platform which is used in the city management center of Guangzhou city. This platform integrates the fixed video resource based on embedded DVR, the mobile in-car wireless video resource based on CDMA x1 wireless network and video resource of mega eyes system. The system provides functions like realtime surveillance, vidicon controlling, record search and record replaying.
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Computer Engineering. 2008, 34(23): 237-238. https://doi.org/10.3969/j.issn.1000-3428.2008.23.084Aiming at the request of Geographical Information System(GIS) system for cross platform multilayer structure, this paper designs VegaGIS visualization system architecture. The architecture realizes the general function of GIS visualization system and the cross platform for OS. It has several characteristics including self-adapting to multiple operating system, dynamic rendering engines, dynamic rendering algorithms, and self-adapting to output devices. The design is implemented on the VegaGIS platform, and is successfully used in several fields.
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Computer Engineering. 2008, 34(23): 239-240. https://doi.org/10.3969/j.issn.1000-3428.2008.23.085
This paper combines multiple description scalar quantization and SPIHT coding to get efficient multiple description image coding over wireless error-prone network. An extension over the two-description multiple description scalar quantization is applied, and SPIHT is employed to encode each description generated from the coarse quantization. Multiple description bit streams which can be transported independently can be obtained. The experimental results confirm that the method performs well especially over the wireless error-prone network. Using this method, it can achieve good error robustness during the transportation over the channels with serious loss rate and limited bandwidth.
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Computer Engineering. 2008, 34(23): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2008.23.086This paper proposes a model of the focus of attention in video sequences. The Itti model has the complex and slow computation, so it reduces computation to monitor the focus of attention through tracking the focus of attention. It uses the similarity between the adjacent frames, establishes the color histogram, selects the maximum similarity as predicable model, and gets position of the focus of attention in the next fame. The experimental results indicate that this model is effective in robustness and real-time.
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Computer Engineering. 2008, 34(23): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2008.23.087As the complexity and uncertainty of the tunnel engineering, there is a considerable risk in the entire construction process. After investigating many history cases, this paper sums up these cases from four aspects, including question, scene, solution and result. To improve the efficiency and accuracy of case retrieving in case-based reasoning, the rough-set theory is introduced to reduce case attributes and get attribute weights. Compared with traditional technique, this technique reduces the subjective effects and improves risk assessment of the accuracy and efficiency, and guarantees the safety of the tunnel construction.
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Computer Engineering. 2008, 34(23): 247-248. https://doi.org/10.3969/j.issn.1000-3428.2008.23.088A multiplier module in Elliptic Curve Cryptosystem(ECC) and Hyper-Elliptic Curve Cryptosystem(HECC) is introduced. On the basis of three existed multiplier algorithms, the hardware configuration is designed and implemented by using VHDL. Moreover, the speed of implementation and the chip area are compared separately. Experimental results show the 8 bit parallel mixed multiplier has better performance than other multipliers.
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Computer Engineering. 2008, 34(23): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2008.23.089Mass data processing and variety of memory medium is existed in the embedded system. This paper designs an Embedded File System(EFS) is which followed by the File Allocation Table(FAT) specification and can be transplanted to variety of the medium. It analyzes the system structure of EFS and lists the bottom-driven design method based on it. Experimental results show that EFS supports FAT12/16/32 format, has high reliability, and adopts modular design to provide standard API function so that it can be transplanted easily. This system is used in the actual products.
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Computer Engineering. 2008, 34(23): 252-254. https://doi.org/10.3969/j.issn.1000-3428.2008.23.090In order to improve the performance of dual-core computer system, this paper proposes a coprocessor model based on Extensible Firmware Interface(EFI) and utilizes dual-core technology and InterProcessor Interrupts(IPI) protocol. In the Driver Execution Environment (DXE)stage of EFI boot process, a user operating system is booted through IPI protocol, and the EFI system runs as a background service system, acting as a coprocessor handling RPC requests from the user operating system. Experimental result proves that the performance of dual-core computer system is improved compared with the one only running the user operating system.
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Computer Engineering. 2008, 34(23): 255-257. https://doi.org/10.3969/j.issn.1000-3428.2008.23.091This paper introduces the principle of touch screen, analyses the reasons that influence the precision of coordinate location of resistive touch screen, and proposes a “three steps” method to improve the precision of coordinate location, including eliminate jitter method by using interrupt and polling, median filtering method and three points calibration method. It tests the algorithm based on developing board of S3C44B0X. Results show that the stability and precision of touch screen system are greatly improved.
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Computer Engineering. 2008, 34(23): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2008.23.092This paper presents a Preconditioned Conjugate Gradient(PCG) method from a view of probability for concrete image reconstruction. This method presents a class of conjugate gradient methods with a new conjugacy condition which is proved under suitable conditions, and combines with a general Conjugate Gradient(CG) method, which lead to PCG method. Computer simulation and concrete model of ultrasonic computerized tomography show that PCG method is more effective to improve the accuracy of computation and the quality of image reconstruction on concrete than the conjugate gradient method.
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Computer Engineering. 2008, 34(23): 261-263. https://doi.org/10.3969/j.issn.1000-3428.2008.23.093Based on the analysis of ARINC664 specification part 7, this paper provides a solution of AFDX switch and key modules of switch chip using FPGA and Verilog HDL description are presented as well. The scheme has past functional, timing and networks simulation. Experimental result shows that this chip can provide guaranteed data communication channels based on switched Ethernet frames, also has high performance and stability.
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Computer Engineering. 2008, 34(23): 264-265. https://doi.org/10.3969/j.issn.1000-3428.2008.23.094Based on the feature of integrated electronics information system for armored vehicle, a basic structure of distributed test system is presented. Network synchronization method for distributed test system is proposed by analyzing the characteristics of LXI bus. Frameworks are composed hierarchically to design the component of test and satisfy the need of the test and control field. This structure is open and extensible.
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Computer Engineering. 2008, 34(23): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2008.23.095A flexible and agile software is needed due to complex and variable business requirements. This paper separates the interface elements from the function codes with the business rules, implementing multi-business user interfaces with minor modification or without modification of the software. Therefore, since the difference of the interface elements among the different businesses is separated, it is achieved to modify the business rules when adding the user interface of the new business or modifying the current interface.
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Computer Engineering. 2008, 34(23): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2008.23.096Aiming at the shortage of the management and service of agriculture economy information at present, this paper researches problem about the application that agriculture economy information service based on GIS and embedded GIS, designs a system structure based on spatial information service system, and develops a soft system about spatial information service system for agriculture economy. Experimental results show that the embedded GIS has a good prospection in agriculture economy data.
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Computer Engineering. 2008, 34(23): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2008.23.097Aiming at the current enterprises information building, a SOA-based application integration system is proposed and implemented .The service total line in enterprise application is adopted to gather applications with no gaps in this structure. This architecture supports service-flow to be arranged in order. It can be used to exploit under the combination of service, makes enterprises to gather different applications of its inner parts and business partners together via various service that this integration system provides, and passes workflow to invoke each other, consequently result in fulfilling a complete, cross-enterprise business target.
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Computer Engineering. 2008, 34(23): 275-277. https://doi.org/10.3969/j.issn.1000-3428.2008.23.098Content based trademark retrieval algorithms use overall shape features or spatial relationships between components to match with features stored in database. However they’re inadequate in anti-noise and always suffer pretermission or false matches when handling trademarks with similar components. This paper proposes a new retrieval method using the Sift descriptor. Experimental results show that this method is more accurate, more complete in retrieving similar trademarks and is more robust against noise compared with existing methods.
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Computer Engineering. 2008, 34(23): 278-179,. https://doi.org/10.3969/j.issn.1000-3428.2008.23.099Aiming at the various characteristic of virus propagation behaviors in complex networks topology, the cellular automata is used to simulate the transmission process of virus. Two models such as Susceptible-Infected-Recovered(SIR) and Susceptible-Infected-Susceptible(SIS) are also used to set up the simulation method for cellular automata. Experimental results show this automata model can simulate the transmission process of virus in complex networks well.
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Computer Engineering. 2008, 34(23): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2008.23.100On the basis of establishing the Open Numerical Control(ONC) system bus interface and communication criterion, a new structure model for Data Link Layer(DLL) with two sublayers based on abstract DLL and real DLL is proposed by analyzing the characteristic of Numerical Control(NC) system. The services and protocol standards of abstract DLL and the encapsulating and mapping between abstract DLL and real DLL are discussed. Moreover, the conversion of services and protocols between application layer and real DLL is implemented.
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Computer Engineering. 2008, 34(23): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2008.23.101As the distribution of high-performance computing resources is inhomogeneous geographically in China Meteorological Administration (CMA), it is urgent to share computing resource in CMA. This paper provides a design of National Meteorological Application Grid(NMAG) based on Uniform Interface to Computing Resources(UNICORE) and implements it. The application shows that the design satisfies the functions of NMAG, the job of meteorological model can be submitted remotely and the result can be got remotely. The high-performance computing resource integration and management is completed in CMA through the system.
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