20 April 2007, Volume 33 Issue 08
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Computer Engineering. 2007, 33(08): 1-2. https://doi.org/10.3969/j.issn.1000-3428.2007.08.001This article investigates a decision analytical tool based on spatial data warehouse——spatial on-line analytical processing(SOLAP) and its support technology. It compares traditional data cube with spatial data cube, the modeling method of spatial data cube is proposed. It solves the problem of the modeling process for spatial dimensions and non-spatial dimension, and also for spatial measure and non-spatial measure.
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Computer Engineering. 2007, 33(08): 3-5. https://doi.org/10.3969/j.issn.1000-3428.2007.08.002Redundant array of inexpensive disks (RAID) is the best way to reduce the disparity between the processing speed of CPU and the ability of I/O system. This paper presents a class of new binary maximum distance separable (MDS) array codes called V codes. The V codes are of minimum column distance 3 and have a simple geometrical structure, namely, they can correct either single burst column error or double column erasure errors. In addition, the parity symbols are evenly distributed among all the columns, thus the bottleneck effects of repeated write operation are naturally overcome. The complexity of encoding and decoding, the small write performance of three types of codes, which are V codes, EVENODD codes, RS codes, are compared and analyzed. The performances of RAID system using V codes are optimal.
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Computer Engineering. 2007, 33(08): 6-9. https://doi.org/10.3969/j.issn.1000-3428.2007.08.003A new framework of automatic test data generation is developed due to the test data generation for control flow and data flow coverage can be merged to path-oriented test data generation in software construction testing. The coverage criteria for control flow and data flow are used to optimize the selection of test path. The approach on path-based automatic test data generation is used to generate test data for the selected path. A prototype on the framework is developed based on the automatic test data generation for path-based, branch and data flow coverage. Test results show that the framework is feasible.
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Computer Engineering. 2007, 33(08): 10-13. https://doi.org/10.3969/j.issn.1000-3428.2007.08.004To overcome the demerits of point-distance-based temporal data analysis and traditional trend sequence analysis, the concepts of number trend sequence, Lp distance of sequences and sequence segmented vector (SSV) are put forward, and three theorems including sequence segmented mean theorem are proved. SSV-based whole sequence matching algorithm is designed to solve the whole match problem of number trend sequences. The algorithm uses radians to measure the trend, takes advantage of time of the trend maintenance to weight the value of trend, and realizes quick whole sequence similarity search of number trend sequences.
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Computer Engineering. 2007, 33(08): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2007.08.005One primary task of Web log mining is to discover and identify users’ access patterns, which provides very valuable potential information for the improvement of Web sites and the users’ personalized service. The paper proposes a concept of Close patterns after analyzing the characteristic of users’ access patterns. A Close algorithm for discovering users’ frequent access patterns is proposed based on this concept. The Close algorithm discovers frequent and Close patterns, which relieves the next phrase workload of finding maximal frequent access patterns to some extent, by making use of the Close property of frequent access patterns. The algorithm performance is tested and analyzed by actual datum.
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Computer Engineering. 2007, 33(08): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2007.08.006A new availability modeling and analysis method——fuzzy stochastic Petri net(FSPN) method is proposed, which integrates fuzzy set theory and stochastic Petri net(SPN). The marking reachable graph of stochastic Petri net is homogeneous with the continuous-time Markov chains. The stability states probability equation can be obtained from the marking reachable graph. To solve the fuzzy equation with fuzzy arithmetic can obtain transfer probability and various performance indexes. An illustrative example is analyzed and compared with existing literature. The result shows that this method is feasible.
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Computer Engineering. 2007, 33(08): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2007.08.007This paper proposes a depth-first algorithm for mining generator representation. Through candidates pruning based on suffix information, it avoids much redundant work and needs not to frequently scan original database. Experimental results show it is an effective method for generator representation mining.
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Computer Engineering. 2007, 33(08): 23-26. https://doi.org/10.3969/j.issn.1000-3428.2007.08.008Being that conventional intrusion detection systems can not adapt to the dynamic grid environment, grid intrusion detection model (GIDIA) based on application of immunity and multi-agent is proposed. In succession to describe the architecture, definitions of immune model, detective agent, decision-making and preventive agent are given. Relevant abstract mathematical models and detailed inferential equations are founded respectively. Theoretical analysis and experimental results show that GIDIA enables member sites in the same trust community or different ones to forewarn attacks cooperatively, and possesses higher detection rate a with better self-adaptability. GIDIA provides a way for implementation of grid security.
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Computer Engineering. 2007, 33(08): 27-29. https://doi.org/10.3969/j.issn.1000-3428.2007.08.009This paper proposes a forward-secure undeniable digital signature scheme based on zero-knowledge proof. By combining the undeniable digital signature with the forward-secure digital signature, the new scheme keeps the general property of undeniable digital signature, and has the character of forward-secure, namely, the loss can be reduced to the lowest once the secret key is lost (or stolen). The scheme has some features such as undeniable and unforgeable of the digital signature, and the size of key and signature are short. The idea of zero-knowledge proof is used in key update protocol, which guarantees key update is secure. The scheme is secure under the assumption of standard intractability problems.
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Computer Engineering. 2007, 33(08): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2007.08.010This paper proposes a fuzzy-based service adaptation model (FSAM). It formulates the service adaptation process by using fuzzy linguistic variables and membership degrees to define the context situations and the rules for adopting the policies of implementing a service. It proposes fitness function to calculate the fitness degree for each policy based on the distance of fuzzy status between the policy and the current context situation. A context-aware application scenario called campus assistant is used to exemplify the proposed service adaptation model and demonstrate its effectiveness.
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Computer Engineering. 2007, 33(08): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2007.08.011A data fusion algorithm is adopted to enhance the performance of auto rate selection mechanism in IEEE 802.11 based on fuzzy system theory, and with the application of this mechanism, the misjudgement of channel state which estimated by single channel parameter is eliminated. In sender, the received signal strength (RSS) and carrier to interface ration (CIR) and packet error ratio(PER) value that sensors obtain is fuzzed, and each of them is used by fuzzy logic control to make part judgement about the channel quality. The best rate is selected based on the decision which obtained through the synthetic operation and decision rule of the data fusion center. Simulation results show that the mechanism enhances mean throughput performance of IEEE 802. 11 system compared with that presented in the literature. Compared with the fixed transmit rate mechanism, the enhancement reaches 28.4 % , and with the single parameter estimated mechanism, the enhancement reaches 22.2 %.
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Computer Engineering. 2007, 33(08): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2007.08.012To overcome the disadvantage of the longtime training of neural network classifier when the distance between samples of different classes is small, the normalization method based on rough set theory is proposed. The samples are normalized using rough set theory and then the normalized samples are used to train neural network. The method is analyzed with an example of faulty line detection for distribution network. The simulation results show that the training time of neural network with processed samples is shorter.
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Computer Engineering. 2007, 33(08): 39-40. https://doi.org/10.3969/j.issn.1000-3428.2007.08.013Emotion has intelligent control on behavior. REB model is ration emotion behavior model. Emotional intelligent control system of softman is made up of ration, emotion and behavior. There are two inner station parameters of Erf and Ecf in this paper. These two parameters can impact emotion. Their effects to emotion control of softman are analyzed. Simulation results prove both Erf and Ecf have effect on emotional control. Besides this, Ecf has better result than Erf. These results are in consonance with human’s experiences.
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Computer Engineering. 2007, 33(08): 41-44. https://doi.org/10.3969/j.issn.1000-3428.2007.08.014Priority reverse is a kind of phenomenon that the higher priority task is blocked by the lower priority task since they are using the same sources in real time system. Priority reverse makes it is impossible to predict the execution time of the high priority task, and increases the indeterminacy of real time system. Although early priorities solved priority reverse, there are some limitations. To address these limitations, this paper gives rise to an improved priority inheritance protocol. In the improved protocol, the semaphores are acquired according to a fixed predetermined non-revolving sequence to avoid dead lock. Protocol establishes overtime protection mechanism to avoid prolonged block when tasks are acquiring semaphores. It analyzes the property of the protocol, on the bases of which an implementation under Linux is described. Experiment results show this protocol can perform efficiently.
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Computer Engineering. 2007, 33(08): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2007.08.015Temporal and spatial reasoning are two important parts of artificial intelligence, and have gained much attention from researchers in recent years. This paper uses multi-dimensional logics as frameworks for knowledge representation and, in particular, for representing spatio-temporal information. It constructs two-dimensional logics intended for describing metric relationships that change over time. The family logic, named PTL-MS, PTL-MS1, PTL-MS2 are the Cartesian product of the well-known temporal logic PTL and the propositional metric logic MS[M]. It provides the intended languages with syntactic and semantics, and investigates the expressive power of them. It can be used in spatio-temporal constraint satisfaction problem, spatio-temporal knowledge base and mobile object database (MOD).
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Computer Engineering. 2007, 33(08): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2007.08.016This paper proposes the method of using equilateral polygon to subdivide the surrounded spherical surface, so as to obtain the projection point and get the two-dimensional projections of 3D models. This method can gain even projection point, and carry on the encryption process to the specific region according to the 3D model’s characteristic, so as to gain more two-dimensional projections information. The method proposed in this paper has already applied in the 3D model recognition and 3D motion recognition work, and obtained good result.
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Computer Engineering. 2007, 33(08): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2007.08.017An information retrieval model based on language concept space and a clustering method which serves the IR model is propsed. The clustering method uses curve-fitting to implement the text clustering by auto threshold-detection means, and complete the whole clustering process through result revising phase. The use of word concept can reduce the word sense ambiguity as drastically as possible when processing the text. The experiments indicate that the method presented in this paper has good performance. Compared with Jelinek-Mercer smoothing model and k-means model, the precision and the recall of the system are higher to a certain degree.
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Computer Engineering. 2007, 33(08): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2007.08.018A proxy signature scheme based on encryption and blind signature has been proposed. However, according to the security analysis of that scheme, the original signer and the blind signature receiver can conspire to change the message to be signed and forge a valid proxy signature without disclosing the secret of the partners, and the proxy signer can misuse the proxy signing power. By changing the proxy signature key into the form of the Schnorr signature and using the proxy warrant, an improved digital proxy signature scheme with privacy protection is proposed, which can withstand the proxy signer’s misuse of the proxy signing power and the conspiring attack of the original signer and blind signature receiver. It overcomes the flaws of the scheme, and has its other security properties.
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Computer Engineering. 2007, 33(08): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2007.08.019The old WCDMA authentication protocol, because of the use of symmetric encryption, is not undeniable and hides some trouble while working. It developed a new authentication protocol from the old one by using EXTR-ElGamal cryptography and modified for the protocol itself. The new protocol is undeniable and the hidden troubles in old one is overcome, while the experimental results show the reality of new protocol. This protocol is more secure than the old one and can be used into reality.
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Computer Engineering. 2007, 33(08): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2007.08.020In active real-time database systems, there are many coupling model between triggering transaction and triggered transaction. The conventional concurrency control algorithm can not schedule availably the transaction having complex coupling model. A new active real-time concurrency control algorithm is proposed after analyzing the coupling model timeliness request and the relation among conflict transactions, which evaluates the transactions cascade depth and adjusts dynamically the commit order of conflict transactions. Theoretical analysis and experimental results demonstrate that the new method can outperform the previous ones.
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Computer Engineering. 2007, 33(08): 63-65. https://doi.org/10.3969/j.issn.1000-3428.2007.08.021This paper presents the implementation skeleton of CORBA/SNMP gateway event management. Aiming at the limitation of CORBA COS event service, there are the corresponding algorithms including grouping, filtering, inserting sequence and resynchronization. It creates a mathematical model and has experiments to test the solution’s feasibility.
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Computer Engineering. 2007, 33(08): 66-67. https://doi.org/10.3969/j.issn.1000-3428.2007.08.022Based on the approximate k-median algorithm, an approximate k-median clustering algorithm for categorical data is developed. The algorithm replaces the modes in k-modes algorithm with the approximate medians of data set, and optimizes the center of cluster with the approximate k-median algorithm. The center of cluster is an actual sample of data set, which prevents the empty cluster. The experiments indicate the algorithm is effective.
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Computer Engineering. 2007, 33(08): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2007.08.023This paper treats the evaluation system of the informatization projects based on the analytic hierarchy process. The analytic hierarchy process (AHP) is a multi-criteria decision method that utilizes structured pair-wise comparisons. Evaluation model of informatization projects is built. The weight of these factors is got by calculating the reciprocal judgment matrix. Satisfying evaluation results are obtained in the practical evaluation process.
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Computer Engineering. 2007, 33(08): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2007.08.024In order to resolve the problems in describing platform independent models of MDA, a modeling approach starting from software architecture modeling is proposed to build platform independent models for Web applications by extending UML and adding user-interface presentation views. It can support model driven software engineering effectively for keeping independency for PIMs and making better use of traceable links established by software architecture between the phases of software lifecycle. J2EE is used as a target platform to help interpreting the transformation from platform independent models built with this approach to platform specific models.
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Computer Engineering. 2007, 33(08): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2007.08.025This paper designs and carries out some experiments on access mode, multiple I/O channel, and system aging problem, etc. It makes use of many kinds of benchmarks to evaluate the performance of the EXT3 and the XFS file system to find how much those factors affect the file system performance. In the experiments, it develops the Thput benchmark which measures metadata performance of the file system and the FastAging tool which can make a file system old very fast. From the conclusion of the experiments, it can choose the most optimal file system according to the application characterization and the hardware configurations to let users get maximum I/O performance.
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Computer Engineering. 2007, 33(08): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2007.08.026Focused on the problems of XML relative path query and XML references query, a path fragment index named KI is put forward. The algorithms about the index constructed and XML data query based on the index are proposed. In order to ensure the stability of XML index query, the index node’s splitting conditions and algorithms are studied. All algorithms proposed are implemented by VC++. Performances of them are studied by experiments. The experiment results show that the query algorithm based KI is effective and efficient.
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Computer Engineering. 2007, 33(08): 80-82. https://doi.org/10.3969/j.issn.1000-3428.2007.08.027Spam filtering is essentially a two-category text classification problem. Feature selection plays an important role in spam filtering. For the peculiarity of the two-category classification problem, improvement on traditional feature-selection approaches can be made. Based on the idea of "contribution difference", improvement on two traditional feature selection approaches, i.e, document frequency and mutual information is made. The experiment results show that the new approach significantly improve classification precisions.
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Computer Engineering. 2007, 33(08): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2007.08.028By analyzing the factors which affect user perceived latency, a method is presented that allows the viewers of Web sites to build their own personalized portals, using specific thematic areas of their preferred Web sites. This method is based on an algorithm which fragments a Web page in discrete fragments with pages’ internal structure. The method can efficiently reduce the response time and improve user satisfaction in the limited network bandwidth and the rising of network flow over network.
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Computer Engineering. 2007, 33(08): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2007.08.029Security is an indispensable part of modern software system, However, the present software system modeling does not deal with security. System security policy and mechanism often become supplement at the end of system development. Such nonstandard security disposal brings much hidden trouble to security maintenance and system integration. Through a student grade management system, this paper talks about how to extend UML notation, modeling for system control policy about security access, how to use view policy language (VPL) to describe correlation of parts and warranty, and how to integrate software system modeling with system modeling securely.
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Computer Engineering. 2007, 33(08): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2007.08.030Most Web pages usually have such noisy blocks as navigation panels, copyright and advertisements, which decreases the accuracies of Web applications system. So eliminating noises content accurately and efficiently is a key technique to improve the service qualities of Web application systems. This paper proposes a novel approach to reduce the noise content in Web pages. It uses a tree structure, called pattern tree(PT), to capture the common layout of the pages in a given Web site. It also introduces an entropy-based measure of the node in the PT to reduce noisy blocks of the site. The approach is applied in a SVM-based Web page classification system. The strong evidence of improvement in applications verifies the validity of the approach presented.
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Computer Engineering. 2007, 33(08): 92-93. https://doi.org/10.3969/j.issn.1000-3428.2007.08.031Generally speaking, people fill data to the template according to the coordinate of the cell during the development of report forms component. But it increases the coupling between the code and the template, and it doesn’t benefit the maintainability and expansibility of the component. This paper solves the problem by user-defined tag, and then presents the method of filling data to the template according to the name of the tag not the coordinate of the cell. In this way, it is effective to decrease the coupling between the code and the template, at the same time, to improve the performance of the component with the pattern of service locator.
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Computer Engineering. 2007, 33(08): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2007.08.032With the embedded system developing rapidly, the real-time operating system VxWorks has been widely used in embedded application. The implementation method of memory allocation is analyzed. This paper introduces segment and page memory management on 80386/80486, anatomizes the memory management mechanism on VxWorks. The DMA memory management on VxWorks is explained as an example, which is used in the transmission of the sound data.
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Computer Engineering. 2007, 33(08): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2007.08.033Adaptive hierarchical clustering algorithm (AHCA) maps a flat topology to a hierarchical one while it almost always introduces a bad degree metric and is not suitable for data distribution. Prune-relocate operation and top topologies operation are proposed to make up AHCA’s shortcoming. Numerical simulation shows that prune-relocate operation reduces the total levels and the average number of hosts in a top cluster. Top topologies operation reduces the load of root. The multicast trees by AHCA and the two operations optimize the overall performance of single-level topology protocol.
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Computer Engineering. 2007, 33(08): 100-102. https://doi.org/10.3969/j.issn.1000-3428.2007.08.034This paper investigates the service combination problem in overlay multicasting network by taking both the service assuring and order of service into consideration. It presents an optimization model and designs a heuristic algorithm on the service combination problem. Large amount of simulations suggest the model and the algorithm are practical and effective.
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Computer Engineering. 2007, 33(08): 103-105. https://doi.org/10.3969/j.issn.1000-3428.2007.08.035TCP-Westwood (TCPW) is shown to provide significant performance improvement in the case of high BER. But its performance gain is achieved on the base of packet losses and its throughput decreases with RTT growing. An improved scheme TCPW-S is proposed in this paper to make TCPW more suitable for satellite network with scarce resource and long delay. After every RTT, congestion window is adjusted to the estimated bandwidth with a conservative policy. Simulation results reveal that throughput of TCPW-S increases while packet losses drop a lot.
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Computer Engineering. 2007, 33(08): 106-108. https://doi.org/10.3969/j.issn.1000-3428.2007.08.036An approach to autonomous systems classification using BGP routing table is proposed. According to the function of ASes in the Internet, this paper treats the Internet hierarchical model as five tiers model. The AS topology is generated from several BGP routing tables. ASes are classified by combinating the structure characteristic of AS path in BGP routing tables, the topology characteristic of transit AS and a method of random distribution. Comparison with similar algorithms shows that the algorithm is simple and effective.
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Computer Engineering. 2007, 33(08): 109-111. https://doi.org/10.3969/j.issn.1000-3428.2007.08.037A new communication model on implementing Anycast service is proposed in this paper and it solves not only Anycast scalability but also other existing problems, such as router table explosion, TCP communication errors, and so on, which are generally caused by performing Anycast services on IP layer. At last, the feasibility and validity of this new model are analyzed and discussed. Meanwhile, according to experimental data, the performance of this model is analyzed.
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Computer Engineering. 2007, 33(08): 112-114. https://doi.org/10.3969/j.issn.1000-3428.2007.08.038This paper presents a cluster intelligent builder(CIB), which is based on the agent technology. Using a kind of system building mechanism, CIB implements the nodes’ automatic configuration, deployment and booting, which builds a customized cluster system. Meanwhile, CIB presents an easy use GUI for the users, which follows the users’ mental model to reduce users’ learning burdens. This paper describes the reason why cluster intelligent builder is proposed, analyses the problems of analogical cluster management software, introduces the agent technology, specifies the details of design and implementation of CIB, and evaluates it from two aspects: the ease of use and efficiency.
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Computer Engineering. 2007, 33(08): 115-117. https://doi.org/10.3969/j.issn.1000-3428.2007.08.039Sensor network is composed of many small, low-power devices with sensing, communication and limited on-board processing capability. The limited power of node and high packet collision with dense node makes noke dissemination necessary. This paper gives a random-sleep node dissemination system based on dynamic neighboring node information, and embedded it into TinyOS as a reusable component. The system is proved through the simulation.
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Computer Engineering. 2007, 33(08): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2007.08.040According to the analysis of the correlative protocol of discovery network 2-layer and 3-layer topology, this paper submits an algorithm of across multi-subnet physical topology discovery that depends on SNMP protocol only. This algorithm has a character that can discover not only the managed devices (e.g. routers and switches), but also the dumb devices (e.g. hosts, hubs and non-managed switches). The experiment demonstrates this algorithm is correct which can discover all sorts of network devices and correctly identifies types of link, and an effective means of solving this problem.
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Computer Engineering. 2007, 33(08): 121-123. https://doi.org/10.3969/j.issn.1000-3428.2007.08.041Ad-hoc network simulation is a basic technique of evaluating new technologies in the development of new network protocols. The modeling problem of network is introduced and a review of the available literature in the field of ad hoc network routing is compared. Then the certain and uncertain modeling are discussed. Several simulation tools such as NS, OPNET and MATLAB are analyzed. Based on uncertain modeling philosophy, a wireless ad hoc networks simulator is designed and implemented with MATLAB and C.
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Computer Engineering. 2007, 33(08): 124-126. https://doi.org/10.3969/j.issn.1000-3428.2007.08.042Based on the analysis on the radio resource management of centralized WLAN network, this paper puts forward the load balance controlling algorithm and the access control algorithm. According to correlated simulation comparison, the algorithms can balance the traffic among the access points more effectively and meet the maximum access service.
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Computer Engineering. 2007, 33(08): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2007.08.043Aiming at the problem that the way of RPC realizing the asynchronous Web service is difficult. This paper proposes one kind new asynchronous Web service solution, namely under the WSE architecture, through bindings between SOAP protocol and message queue, achieves the SOAP messages asynchronous transmission, thus realizes Web service asynchronous invoking.
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Computer Engineering. 2007, 33(08): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2007.08.044On the basis of analyzing the traditional spam filtering techniques, this paper presents a novel anti-spam technique based on the users feedback. By introducing the novel users’ feedback mechanism, the technique adopts an improved Naïve Bayesian approach to construct classifiers for specific users to fulfill spam filtering. Experiments on well-known mail corpus and prototype demonstrate that the technique is able to reduce false positives and improve the availability of anti-spam system.
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Computer Engineering. 2007, 33(08): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2007.08.045A secure complicated information system architecture model is introduced to construct a secure, interoperable and extensible CIS. The model divides CIS into several layers to reduce system complexity. It uses Web service technique to realize the interoperability and extensibility. It introduces encryption support layer, security protection and reliability support layer to guarantee the system security and make the CIS administrable with system management layer. A study of E-government case with performance analysis and simulation proves that the model suits security-critical complex information system.
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Computer Engineering. 2007, 33(08): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2007.08.046Athena approach can not analyze some complex security protocols because of its poor cryptographic primitives. This paper extends theory of Athena approach according to IKEv2 protocol. In the structure of message terms, some cryptographic primitives are added to handle DH key agreement, and the in-term relation is modified to deal with complex message structure. In addition, the secrecy, authentication and some other properties of IKEv2 protocol are analyzed with the proposed approach.
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Computer Engineering. 2007, 33(08): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2007.08.047The P2P-based worm is a kind of malicious code that takes advantage of P2P system to propagate. Because hosts in P2P system maintain a lot of neighbors list, infected hosts in P2P systems can easily propagate the worms to its neighbors. It can spread with high speed, which would lead to network congestion. This paper addresses the issue by analyzing the theory of P2P worm’s propagation and presents a mathematical model that takes into account bandwidth and the time of treatment response. In particular, it studies bandwidth affecting the worm propagation in the aspects of saturation and congestion. Furthermore, it studies the measure of defense based on the propagating model. From the simulation experiment, it can describe the process of worm’s propagation in a P2P system.
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Computer Engineering. 2007, 33(08): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2007.08.048A video watermarking robust algorithm to geometric distortion is proposed. During the watermark embedding process, synchronization information is embedd in several frames. The algorithm takes advantage of the feature points of synchronization frame to recover the attacked digital watermarking video sequences. According to the position of feature points between the original frame and the attracted frame, the video sequences are rectified. The experiments demonstrate that this scheme can efficiently prevent temporal synchronization attacks as frame dropping, frame insertion and geometric attacks.
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Computer Engineering. 2007, 33(08): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2007.08.049This paper analyzes the security of multimedia copyright protection systems that use watermarks by proposing a new method of attacks on some watermarking systems. Such idea comes from the observation of the repetitiveness of the multimedia content. The attack procedure replaces each signal block with another computed one. If the computed replacement block is at some minimal distance from the original marked block, large portion of the embedded watermark is irreversibly removed. The logistics of the attack and an exemplary implementation against a spread-spectrum data hiding technology for audio signals are also described.
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Computer Engineering. 2007, 33(08): 148-149. https://doi.org/10.3969/j.issn.1000-3428.2007.08.050The paper analyzes the security of an efficient revocation algorithm which was proposed by Chen in 2003. Security flaw is identified in their scheme. The paper proposes an attack to this flaw, it shows a deleted member can forge valid group signature. So their scheme is insecure.
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Computer Engineering. 2007, 33(08): 150-151，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.051To authenticate the identity and distribute the private keys of users based on the stream media cryptographic system, a new scheme is proposed by integrating the idea of traditional PKI into IBE system, certificate authority and the concept of public-key certificate are used in the new scheme to set up the secure channel for transmitting the private keys. The private key distribution problem is addressed in the new scheme, and the secure performance of the system is improved. At the same time, the number of authentications decreases significantly, and the calculation amounts and communicative expenses of the system reduce.
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Computer Engineering. 2007, 33(08): 152-153，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.052For the problem of high false-positive rate and not sensitive to new intrusion method existed in the intrusion detection, a new intrusion detection method based on neural network ensemble is proposed. It trains the neural network ensemble with negative correlation learning method, uses tf×idf(term frequency ×inverse document frequency)system calls encoded mode as the input. The experimental results indicate that, compared with ANN, neural network ensemble improv the performance of ANN in the data analysis, keeps high detection rate and low false-positive rate.
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Computer Engineering. 2007, 33(08): 154-156. https://doi.org/10.3969/j.issn.1000-3428.2007.08.053Excluding the main issue of intrusion detection system (IDS): implementation of intrusion detection algorithm, this paper concentrates on other issues of IDS: sensor and analyzer, and proposes some advices that can improve the veracities, the throughout and the self-study abilities of the IDS via the studies and analyses on sensor and analyzer. Based on it, some ideas are implemented to a distributed intrusion detection system (DIDS) model that most of certain intrusion detection algorithms can be applied to it. Meanwhile, the advantage and disadvantage of the DIDS model are discussed.
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Computer Engineering. 2007, 33(08): 157-159. https://doi.org/10.3969/j.issn.1000-3428.2007.08.054This paper presents a method of information hiding algorithm based on optimal LSBs substitution and image visual perception. In this method, according to the characteristics of human vision sensitivity, the hard c-means cluster is used to identify the complexity of the cover-image. To improve the quality of embedding result, an optimal pixel adjustment process is applied to the stego-image. The scrambling technology based on spatiotemporal chaos mapping can be used to solve the problem that the hiding algorithm can not provide the way of protecting the secret information. The initial parameters of the spatiotemporal chaos mapping can act as the private keys, which can provide larger key space. Experimental results show the proposed algorithm can make a great improvement in both the imperceptibility and the quality of the cover-image.
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Computer Engineering. 2007, 33(08): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2007.08.055An approach to constructing interpretable fuzzy system based on fuzzy clustering and genetic algorithm is proposed. The precision index is defined, and the necessary conditions of interpretability are analyzed. The initial fuzzy system is identified using fuzzy clustering algorithm and the least-squares estimator. Genetic algorithm is used to optimize the initial model. Similar fuzzy sets merging and fuzzy rules merging are adopted to reduce the fuzzy model to enhance its interpretability. The proposed approach is applied to the Mackey-Glass system, and the results show its validity.
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Computer Engineering. 2007, 33(08): 163-164，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.056All of the automatic plan-based instruments in program comprehension acquire relevant semantic information by comparing the source codes with the standard plans in pre-constructed plan database. The rough-match based on applying characteristic symbol as the index can greatly accelerate the matching progress, but it also brings the disadvantage of information leak. This article proposes a refined-match method based on fuzzy reasoning to analyze the similarity between the potential plans and the source codes, and gets the ranked candidate plan set.
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Computer Engineering. 2007, 33(08): 165-167. https://doi.org/10.3969/j.issn.1000-3428.2007.08.057Most Chinese text classification methods are applied to the machine learning technologies, while ignoring the traditional methods based on decision rules. This paper combines them into a whole classifier, taking the rule-based learner as a component classifier, and proposes a new optimized rule induction algorithm for the purpose of automatic generated “strong” decision rules. The experiment result shows that the mixed classifier outperforms the single N-Gram classifying method based on machine learning.
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Computer Engineering. 2007, 33(08): 168-169，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.058The paper studies enhancement algorithm on mammograms, and quantitative measures of contrast enhancement. The gray homogeneity is defined by edge value, standard deviation, entropy and the fourth moment for mammograms. The amplifier is presented to adjust the contrast enhancement in the whole image. Then the homogeneity based-on algorithm is applied to enhance mammograms. Four quantitative measures of contrast enhancement are put forward. The presented algorithm is compared with two other existing contrast enhancement techniques-histogram equalization and morphological enhancement. The index shows that the presented algorithm performs better than histogram equalization and morphological enhancement. A lot of experiments and comparisons are needed to study the relativity among DSM, TBCs, TBCe and the final index. Based on those, contrast enhancement algorithm for mammograms and rational evaluation system and measures can be found.
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Computer Engineering. 2007, 33(08): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2007.08.059A hybridization of the PSO with density-based clustering algorithm is presented in the paper. The algorithm is suitable to process the incremental data compared to the DENCLUE. Besides, the resource used in the algorithm is limited. Several experiments are performed to test the algorithm. The results indicate the efficiency of the algorithm.
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Computer Engineering. 2007, 33(08): 173-174，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.060As one of effective automated reasoning methods, Tableau is applied to many important AI fields. On the base of Tableau, an open and close new reasoning criterion is proposed. The criterion is applied to inconsistent relational database which database instances can not satisfy integrity constrains. Database can be repaired through logic programming, which can solve some problems such as losing information, arising new inconsistent.
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Computer Engineering. 2007, 33(08): 175-177. https://doi.org/10.3969/j.issn.1000-3428.2007.08.061Location and binarization are vital in license plate recognition. Only single step is taken in traditional way so as to meet the demand of recognition time. But because of the flaw of arithmetic, it is not very adaptive to some particular images, which leads to the failure of recognition. In order to solve this problem and satisfy the need of recognition rate meanwhile, this paper gives a new way composed of two steps based on modification, which can improve the effect of binarization and location to offer an accurate input for the next process.
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Computer Engineering. 2007, 33(08): 178-179，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.062The generalized Hough transform for the recognition of irregular objects is a powerful method, since it can detect overlapping objects under severe noise. The conventional computation method of the R-table’s index is sensitive to discontinuity and distortion. So the GHT’s robustness is degraded a lot. To solve the problem, this paper proposes a new procedure for calculation of the normal direction of each point. Characterizing the edge points by their normal directions can improve the GHT’s robustness to discontinuity and distortion. Experimental results demonstrates that the improved method does work well for objects recognition. And the shoe sample could be detected accurately despite of noise, discontinuity or geometric distortion in the system of shoe sample CAD.
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Computer Engineering. 2007, 33(08): 180-181，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.063Automatic summarization is one of main research fields in natural language processing. This paper proposes a special Chinese automatic summarization method based on discovering thematic sentences, which uses terms as minimal semantic unit rather than word, and employs term length term frequency (TLTF) to compute weight of term to obtain feature. It uses an improved k-means method to cluster sentences, and discovers thematic sentences according to clustering results. Experimental results indicate a clear superiority of the proposed method over the traditional method under the proposed evaluation scheme.
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Computer Engineering. 2007, 33(08): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2007.08.064Feature selection is very important in improving the performance of learning systems. Various feature selection algorithms greatly facilitate the research of the scientists from different disciplines, there is a common problem that those algorithms are implemented by different researchers. So it is hard for the users to integrate or compare those independent implementations of different programming styles and incompatible designs. The feature selection library on strategy pattern(FSL-SP) is conceived to solve the above problem. The FSL-SP encapsulates many popular feature selection algorithms under unified interfaces, while different strategies of one algorithm could be exchanged conveniently. This library will bring help to those machine-learning algorithms users. The FSL-SP itself has good extensibilities, and new algorithm can be added into the library easily.
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Computer Engineering. 2007, 33(08): 185-186. https://doi.org/10.3969/j.issn.1000-3428.2007.08.065This paper presents a method of minutia detection based on tracing fingerprint ridges. By tracing ridges it seeks and verifies minutiae, and locates them with their relative position to the central point of the fingerprint image. It can remove the disturbance of the fingerprint image’s rotation and distortion, greatly enhance the precision of fingerprint verification.
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Computer Engineering. 2007, 33(08): 187-189. https://doi.org/10.3969/j.issn.1000-3428.2007.08.066Aiming at traditional BP neutral network weight algorithm’s defect such as slow convergence and easy to plunge into local extremum, an adjustable parameter feedforward neutral network and a fast algorithm to train it are proposed on the basis of weight balance algorithm. Based on the search technique of non-monotone heuristic simulated annealing proposed, the algorithm realizes fast search of network weight and parameter. Experiments show that this algorithm can speed up the learning process of network, and solve the problem of local extremum in learning process to a certain extend.
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Computer Engineering. 2007, 33(08): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2007.08.067Aiming at the faults of current anti-money laundering system, this paper takes full advantage of agent system which is autonomy, reactivity and initiative to constructs the model of anti-money laundering system based on multi-agent with pattern recognition. And researches on Rey problems such as communication, negotiation and realization of multi-agent and pattern recognition using SVM are made to offer support for realization of anti-money laundering system.
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Computer Engineering. 2007, 33(08): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2007.08.068Support vector machines (SVM) are efficient in a large number of real-world applications. However, the classification results highly depend on the parameters of the model. For any SVM classification task, the best values for these parameters are usually picked by experience, experiment compare and large-scale search, or using cross validation providing by software package to optimize. For optimizing SVM hyper-parameters, this optimization scheme minimizes an empirical error estimate using a quasi-Newton optimization method on the validation set. The method shows satisfactory results in feather and down category recognition.
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Computer Engineering. 2007, 33(08): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2007.08.069This paper introduces a method to extract unknown Chinese words based on statistic and regulation. The process comprises two parts: (1) It segments the full text and combines the adjacent single Chinese character to short strings (fragments), then uses full-segmentation method to divide each fragment into strings, and each string is assigned a term weighted by rules and frequency. It uses the greedy algorithm to get the longest path of each fragment; every string except single character in this path is an unknown word. (2)It builds a bi-gram model and uses mutual information to combine some adjacent words to unknown words. The precision on the open test sets is 81.25% and recall is 82.38%.
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Computer Engineering. 2007, 33(08): 199-200，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.070The fault diagnosis for oil field compressor is not efficienct and not automatic, so a type of fault diagnosis system for oil field compressor is designed, the system is constructed by an expert system and a BP neural network, the expert knowledge and the numeric reasoning capacity of the neural network are applied to analyze the compressor fault. Contrast to the old method, the system is automatic and diagnosises accurately and credibly.
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Computer Engineering. 2007, 33(08): 201-204. https://doi.org/10.3969/j.issn.1000-3428.2007.08.071Feature weighted is the general case of feature selection, which has better performance than (or at least has the same performance as) feature selection. In this paper, feature weighted is employed to improve the classification accuracy of the category ART networks. A novel network named FWART network is proposed, in which the self-adaptive genetic algorithm is used to optimize the weight vector. Experiments on the UCI datasets show that the FWART has better generalization power than Category ART. It is applied to predict the earthquake type. The result is satisfactory.
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Computer Engineering. 2007, 33(08): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2007.08.072A new SVM iterative algorithm is proposed, aiming at the problem that the speeds of learning and classifying are slow in large training set. K-mean clustering algorithm is used to get the original training set, the clustering center is considered to be the original training set, and so reduces the redundance of samples. The margined samples and error-classifying samples are joined in the original training set to renew it. Iterative training is done till the error-classifying samples’ number is not changed. The experiments show that, by this iterative algorithm, the scales of training data and the support vector set are effectively compressed. So the speeds of learning and classifying are accelerated while keeping the same learning precision.
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Computer Engineering. 2007, 33(08): 208-209，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.073This paper describes an algorithm framework for building recognition in urban area image sequence. Three image sequences and DSM from multi-view match are used as sources of information. A homologue feature matching, based on geometry constraint, is applied for automatically generating 3D point and line. Features are grouped based on perceptual organization criteria. And an optimized texture extraction and mapping strategy are discussed.
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Computer Engineering. 2007, 33(08): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2007.08.074H. 264 video coding standard introduces motion estimation with multiple block sizes to achieve a considerably higher coding efficiency than other video coding algorithms. This comes at the greatly increased computing complexity at the encoder. A method is proposed to eliminate some redundant coding modes that contribute very little coding gain based on analysis of macroblock detail-level and texture directions. The simulation results show that the algorithm can remarkably decrease the complexity at the encoder while keeping satisfying coding efficiency.
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Computer Engineering. 2007, 33(08): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2007.08.075This paper describes still medical image compression, introduces two image compression standards, JPEG and JPEG2000. By comparing the two standards, JPEG2000 is superior to JPEG. The modern technology, namely JPEG2000 is presented. The JPEG2000 basic configuration and the encoding and decoding technique are given. A design of image compression based on DSP is described. The system uses CCD for getting digital image, and adopts a sixteen-bit fix-point DSP to perform wavelet transform arithmetic and image encoding. The proposed technique aims at reducing the transmission cost while preserving the diagnostic integrity. The experimental results indicate that using JPEG2000 standard can ensure an optimal trade-off between the image reconstruction quality and the compression ratio.
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Computer Engineering. 2007, 33(08): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2007.08.076A new binocular vision system for explosive-handling robot is designed. The vision system can capture real-time images, make camera calibrations with Zhang’s method, preprocess images, match feature point, and get the stereo coordinate of the feature point of the suspicious objects. With Matlab7.0 and EasyMultiCam of eVision6.2, the system displays the real-time images on the control panel and controls explosive-handling robot to grasp the suspicious objects accurately. Experimental results indicate the validity in real-time performance and precision of the vision system.
【Key words】
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Computer Engineering. 2007, 33(08): 219-221，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.077This paper presents an object-oriented anti tactical ballistic missile simulation system for air defense, called ATBMS, for simulating modern day combat dynamics of air defense simulation involving multiple targets and multiple platforms. CMMS based description of simulation domain can be systematically translated to build an object-oriented simulation, and CMMS common representation templates can be effectively used to design and implement scenario based military specification. Moreover, the separation of the relatively static simulation architecture from the evolvable problem domain modeling for specific application scenario provides users with modularity and extensibility by encapsulating the sequencing information derived from the domain modeling as a part of the simulation architecture.
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Computer Engineering. 2007, 33(08): 222-223，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.078Cellular automaton model is applied to analyse the traffic flow of five crossings. This paper establishes traffic model of five crossings by analysing road factor, vehicle factor and the moving rules. Four crossings is usually divided into two phases: east-west phase and south-north phase. But it needs another phase to compose three-phases’ control in five crossings. Every phase is separated into six driveways which are numbered to ascertain the vehicles’ positions; all of the vehicles are transformed to subminiature ones; any vehicle in each phase should be analysed according to the color of light which contains two states: green and red. VC++ is chosen to be the emulational tool, three timers are used to produce dynamic menu of five crossings. The model can set the parameters of flux and travel time during the emulation to simulate the actual traffic flow. So the emulation can be well repeated.
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Computer Engineering. 2007, 33(08): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2007.08.079The paper presents a dual fault-tolerant system and its process of synchronization in order to make two computers work in phase. The synchronization is based on task, and realized with the cooperation of dual-computer controller and outer memory. When both computers are well, the applications in two computers work disorderly, but the information of synchronization is stored in outer memory, guaranteeing the correctness of the system outcome. Simple criterions of applications make the system more flexible, with high performance of single computer and high reliability of the whole system reserved. Corresponding solutions for key points such as the switch between two computers are put forward.
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Computer Engineering. 2007, 33(08): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2007.08.080According to the characteristic of tributary unit(TU) point justification in synchronous digital hierarchy (SDH), this paper provides a method of software and hardware for designing adaptive bit-leaking. The content is a solution of making random signal, designing the software flow, and circuit design. Then it gives the result of four tests for combined jitter measurement in SDH.
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Computer Engineering. 2007, 33(08): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2007.08.081Based on the analysis of single application smart cards and the key technologies of multi-application smart cards, a system prototype of cross-industry multi-application smart cards is proposed. System security and key technologies of sub-modules are studied. This prototype is implemented with Java Card technology. The implementation is evaluated, and the future work is discussed.
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Computer Engineering. 2007, 33(08): 233-234，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.082To protect intellectual property and meet the requirement of outdoor operation in remote sensing work, a hardware system which is composed of DSP and CPLD and USB to implement the 6S (second simulation of the satellite signal in the solar spectrum) algorithm is proposed aiming at some characters of the algorithm. The scheme of the system and the design process are discussed.
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Computer Engineering. 2007, 33(08): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2007.08.083To realize the functions such as resource sharing and teleoperation, the Web-based remote Chinese characters’ engraving system for parallel engraving machine is proposed. Three parts function, i.e. motion control, engraving control and video feedback, are provided by the system. Supervised control model is adopted to decrease the influence on engraving control as transmission delay, the sharing collision is prevented by applying mutual exclusion principle between progresses, the real-time control of engraving job can be guaranteed with multithread and shared variables mechanism. The real-time transmission of video information is implemented based on JMF(Java Media Framework) and IP multicast respectively for image acquisition card with different types. Experiment results show the feasibility and validity of the proposed methods.
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Computer Engineering. 2007, 33(08): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2007.08.084Earth-rock volumes allocation scheme in any time range can be generated using dynamic linear planning algorithm by an intelligent earth-rock volumes allocation system, which collects all project data and geographical data and digitizes them into database server. The reliability, feasibility and quality of operation of the generated scheme is influenced by database structure because of tremendous data of the project which change frequently. By analyzing requirements, a database structure is designed and an intelligent earth-rock volumes allocation system is developed and the system is successfully applied in the highest rock-fill dam in the world currently and the database system runs well. The results of computer simulation based on project data and historical construction data are technically feasible and better than those of traditional construction management ways.
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Computer Engineering. 2007, 33(08): 241-243，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.085This paper analyzes the principle of iSCSI protocol, and puts forward the way that uses the parameters of iSCSI protocol to implement the iSCSI protocol over OPNET8.0, and based the emulational model. The emphasis is the way to implement the SCSI layer and iSCSI layer, and it puts forward the state in which the facility is, and puts forward the process of implementation of the two layers over OPNET.
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Computer Engineering. 2007, 33(08): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2007.08.086According to load characteristic of the water-resistance load used in diesel generator’s load-test, this paper analyzes recent research on water- resistance’s model and control, provides the analyzing process of control solution about the fixed current based the fuzzy controller of original practical project, and fulfills the control with self-organized fuzzy control theory. An improved method is proposed. It provides the analysis and the simulation about the original fuzzy controller and the improved fuzzy controller.
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Computer Engineering. 2007, 33(08): 247-249，. https://doi.org/10.3969/j.issn.1000-3428.2007.08.087Based on the analysis of the new requirements to the collaborative process planning supporting network-based manufacturing, the system architecture consisting of user layer, application server layer and database server layer is constructed, and then some key technologies such as modeling of process information, integration technology based on XML and COBRA and collaborative technology of process planning are discussed. Finally, a prototype of NM-COCAPP is shown.
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Computer Engineering. 2007, 33(08): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2007.08.088Given expression and organization of part information in computer aided process planning (CAPP) application system, ontology-based description model of part information and its three-layer framework are proposed. The description pattern of part features and its structure are also presented. Finally a typical example indicates that ontology description of part information is reasonable and effective.
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Computer Engineering. 2007, 33(08): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2007.08.089A kind of highly reliable fault-tolerant server with excellent performance which combines COTS technique and traditional fault tolerance technique is designed and realized in this paper. The server is based on the state-of-the-art hardware and software. It is open and adopts transparent fault tolerance with low cost and strong scalability. The paper highlights key design principle and roll-forward fault recovery technique of the server.
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Computer Engineering. 2007, 33(08): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2007.08.090Evaluation and certification of information security products is important to the information security of the nation. The paper analyzes the problems faced in the evaluating process, points out the requirement and object of the evaluation platform. Then, it describes the design, module structure and realization of LOIS evaluation platform. It is a highly automated and centralized platform, supports multi-criterion and can be expanded easily.
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Computer Engineering. 2007, 33(08): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2007.08.091Based on the bank and power supply enterprise network, this article presents the software architecture, design methodology and implementing details of the electricity fee payment system, focusing on the key techniques of proxy design pattern and network programming with sockets. The functionalities and security enforcement mechanism of this system demonstrate that the system is viable in reality.
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Computer Engineering. 2007, 33(08): 262-263. https://doi.org/10.3969/j.issn.1000-3428.2007.08.092A directional method that combines multimedia communication with information release based on Web mode is introduced. The system consists of three subsystems, information release, graphic processing and multimedia communication. Display of troop disposition, equipment deployment, facility deployment and manoeuver in military electron map are realized in the system. The giving of real-time directional orders, reporting of campaign complexion and monitoring of the situation are implemented by using informational interaction, such as typewriting, audio, video and tabula.
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Computer Engineering. 2007, 33(08): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2007.08.093This paper introduces a solution with method of modeling and optimization to simulate fire animation based on article system on the platform of J2ME. The method involves 4 aspects: analysis of the character of fire, creation of colour pane, designment of algorithm and optimization of algorithm according to the mobile platform. It shows how to realize the fire effect in the mobile games on J2ME.
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Computer Engineering. 2007, 33(08): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2007.08.094Studying in how to develop a UML Syntax-analyzer is significant for there are many researchs on object-oriented test with UML class diagram and statechart diagram at present. The paper develops a UML analyzer by using BISON, which realizes getting information used to software testing automatically from documents of UML by scanning and analyzing them. It improves the efficiency of software testing. Simulating the software under the environment of VC6.0 and the results show that it can work correctly.
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Computer Engineering. 2007, 33(08): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2007.08.095Based on the basic principle of MPEG-4 video compress card, this paper presents the general framework of developing device driver on Linux platform and describes the design and the implementation of the MPEG-4 video compress card driver, including relevant functions and programs. The experiment results prove the feasibility of the driver.
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Computer Engineering. 2007, 33(08): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2007.08.096Based on the session initiation protocol (SIP), this paper analyzes some kinds of network structures applied in system, and proposes a mixed network structure for the multi-domain and multi-transmission-medium E-education system. It discusses the principles of such kind of system in detail, and depicts the function of each unit and the method to achieve it, which provides an idea to develop the E-education system.
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Computer Engineering. 2007, 33(08): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2007.08.097It is necessary to evaluate the operational capability of weapon equipment during its demonstration, however, the data to be dealt is often not the fighting results data with different sorts, and they are uneasy to fuse. And therefore, a comprehensive method based on TOPSIS, AHP and Simulation method is built to evaluate the operational capability of weapon equipment(TAS). An example about the operational capability evaluation on armored equipments under the mission simulation is analyzed, and the evaluation results agree with the fact results. Result shows the comprehensive method is rather feasible.
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Computer Engineering. 2007, 33(08): 279-281. https://doi.org/10.3969/j.issn.1000-3428.2007.08.098This paper takes the embedded USB host system based on ISP1362 as the research object. It analyses two kinds of USB system’s errors in the view of USB host and proposes some solutions. The design of transmission-level error correction includes control transmission and batch transmission, and class protocol error correction includes Recovery processing, Sense Code processing and USB transmission reset.
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Computer Engineering. 2007, 33(08): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2007.08.099The semantic Web technology is introduced in the E-learning to construct a learning resource ontology based on semantic Web architecture and realizes further management of the learning resources in E-learning system. After analyzing the functions and scope of Web-based education resource library and the methods of ontology modeling, upper ontology is illustrated which includes the resource library ontology and the users’ ontology. And the class diagram is shown. Corresponding OWL description of ontology is implemented with Protégé3.1. The evaluation of ontology is given, and an inference instance proves its validity.
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