20 February 2007, Volume 33 Issue 04
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Computer Engineering. 2007, 33(04): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2007.04.001Based on the hierarchy model of storage system, there are a few strategies and mechanisms to implement storage security. This paper analyzes several storage security implementation on application-layer or operating system layer, lists their virtue and disadvantage, brings forward a hardware security schema based on block layer, and achieves transparency and completeness in real time and without lowering performance of the system. It gives description of implementation of schema based on FPGA and analyses the performance of the two kinds of implementation structure.
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Computer Engineering. 2007, 33(04): 4-7. https://doi.org/10.3969/j.issn.1000-3428.2007.04.002Searching useful people from talent database effectively and efficiently is very important for large group corporations, especially for water conservancy and hydroelectric power operation corporations. However, traditional retrieval methods can not well satisfy their demands. This paper puts forward a retrieval method for large talent database based on ontology using semantic Web technology. RDF is applied to describe ontology in the database and transforms search conditions into semantic information. And match calculation model is used to search for people needed. An example is presented to illustrate the application of the method.
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Computer Engineering. 2007, 33(04): 8-10. https://doi.org/10.3969/j.issn.1000-3428.2007.04.003To enable a dynamic, collaborative and heretical mobile manufacturing collaboration process, the concept of mobile manufacturing collaboration chain is proposed. And role-activity model is put forward to implement it. Based on specific requirement, the model focuses on relationship between roles, activities and workflow. By coding attributions of roles’ and activities’, modification of chain is implemented through genetic operation, such as crossover, copy, mutation and clone. Along the sequence of activities definition, roles definition, templates definition, projects definition and chain models are established. A developed prototype shows that role-activity model meets the need of process modeling in mobile manufacturing collaboration.
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Computer Engineering. 2007, 33(04): 11-13. https://doi.org/10.3969/j.issn.1000-3428.2007.04.004By investigating the inherent pairwise similarities implicitly defined by the kernel function, this paper defines two statistical similarity coefficients, named as within-cluster and between-cluster average similarity coefficient, which can be used to describe the internal and external similarity between the data items, respectively. And then, an efficient validity index for kernel clustering algorithm is proposed, which has distinct physical meanings, less computational complexity and a certain robustness with respect to Gaussian kernel width. In addition, a self-adaptive kernel clustering (SAKC) algorithm based on the proposed validity index is also developed. The benchmark results demonstrate the effectiveness and performance of the new validity index of SAKC algorithm.
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Computer Engineering. 2007, 33(04): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2007.04.005In order to improve the quality of traditional clustering algorithm and prevent the distribution of data from affecting the clustering algorithm greatly, a clustering algorithm based on rough set is proposed. Depending on the consistency of condition attributes and decision attributes in the decision table, the data is discretized and attributes are reduced by using data super-cube and information entropy. Based on the above, the algorithm can use the additivity of set feature vector to cluster data just by scanning the decision table only one time. Illustration indicates that the algorithm is efficient and effective.
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Computer Engineering. 2007, 33(04): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2007.04.006Ethernet media access control (MAC) address lookup is one of the design challenges of high-performance Ethernet switch chips. In this paper，the trie of four address nodes in one hash bucket are compacted into a 25-bit word. The search procedure based on the compacted word is performed by a three-stage pipeline，which runs at over 133 MSPS on FPGAs. The address-learning algorithm can perform 1 million updating operations per second with one of six micro-engines in IXP1200. With this scheme，memory bandwidth in searching can be decreased by half，and the MAC address forward table can be placed in the high capacity commercial memory modules. Compared with the switch chips whose forward table is placed in the embedded memory，its hash table capacity is higher and the collision rate is much lower.
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Computer Engineering. 2007, 33(04): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2007.04.007To solve the problems of strong subjectivity, poor efficiency and high cost in traditional workflow modeling, a novel modeling method automatically deriving model from workflow logs is appeared, which is called as workflow mining. At present this method is in primary stage in the world, but it has aroused extensive solicitude. This paper summarizes the scholars’ main studies in workflow mining, introduces the modeling process of two different kinds of mining algorithms in detail, compares and analyzes their performances, and explains the modeling process with an actual example.
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Computer Engineering. 2007, 33(04): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2007.04.008An evolutionary approach for designing compact fuzzy classifier directly from data without any a priori knowledge of the data distribution is proposed. The variable input spread inference training (VISIT) algorithm is used to create each individual fuzzy system, and then searches the best one via genetic algorithm. Rules and membership functions are automatically created and optimized in an evolutionary process. In order to effectively evaluate the accuracy and compactness simultaneously, a fuzzy expert system acts as the fitness function. The experiments on two benchmark classification problems show the effectiveness of the new method.
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Computer Engineering. 2007, 33(04): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2007.04.009One important application of microarray data is to classify samples of disease. The feature of microarray is the that number of sample is small and the dimension of the sample is very large. The paper gives a noval approach to solve it. The approach is applied to acute leukemia data set. This procedure involves dimension reduction using t_statistic and classification using covering algorithm. The experiment result shows the method is effective by comparing with other methods.
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Computer Engineering. 2007, 33(04): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2007.04.010The traditional transactional workflow is conditioned by complex information environment (collaboration of various applications, long lived transaction), because it is designed for short transaction. This paper analyses the shortcoming of known methods to solve LLT problems, and presents the minimum atom range aggregation method based on the layered network of transactional object, it also describes the detailed computation of smallest atomic scope. An injection mold product development process is presented as an example of the method to prove its validity.
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Computer Engineering. 2007, 33(04): 32-33. https://doi.org/10.3969/j.issn.1000-3428.2007.04.011As ideas of neural networks and logic inference are introduced into the theory of object-oriented, an intelligent neuron model is built. This model, with the characteristic of neural networks and expert system, integrates the link mechanism with the symbol mechanism. Then a new programming language——intelligent neural network programming language called NIPL is presented. NIPL makes the unification of neural network computation, logic inference and numerical computation. The abstract grammar of NIPL is given. The compiler of NIPL is designed and implemented and thus an effective means for development of the intelligent system is provided.
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Computer Engineering. 2007, 33(04): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2007.04.012This paper puts forward a parallel algorithm named Ptree-DM to mine association rules from distributed transaction databases without generating candidate item sets. The remarkable characteristic of Ptree-DM is that it needs a few synchronization times and generates a little network flux. It provides an example to show how Ptree-DM works, and discusses the efficiency of Ptree-DM.
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Computer Engineering. 2007, 33(04): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2007.04.013With the vision of anytime anywhere computation, the availability measurement is playing an important role in pervasive computation. In the perspective of quantitative analysis, this paper presents an MRGP-based approach to address the user associated availability measurement of pervasive computation system. A bidirectional extended user model is developed for describing user behaviors. An MRGP model is established, and a stochastic process-based analysis is conducted. The transient and steady availability are provided for this model, and a novel availability metric, called request availability, is suggested. Numerical analysis is carried out and the results argue that the approach and availability metric can give reasonable evaluation for pervasive computation system.
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Computer Engineering. 2007, 33(04): 40-41. https://doi.org/10.3969/j.issn.1000-3428.2007.04.014Most of the defects and errors in the software coded in C++ are memory-related. Based on the practice in the "network, large volume spatial information oriented GIS" project, this paper presents the techniques and tools to find and fix the memory problems during the coding, debugging and production release phase with the support of the C++ language mechanism, development environment and related quality-assurance tools.
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Computer Engineering. 2007, 33(04): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2007.04.015This paper describes a new model for collaborative filtering, it can be used to slove the problem that two users with similar preferences on items may have different rating schemes. This model may effectively improve the traditional collaborative filtering method used to compute the similarity between users, and enhances the accuracy of user similarity measurement. Experiment results show that the new model performs well in personalized recommendation system.
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Computer Engineering. 2007, 33(04): 45-48. https://doi.org/10.3969/j.issn.1000-3428.2007.04.016Analysis and forecast of SARS epidemic situation by using gene expression programming(GEP) is reported. The paper applies the GEP to the analysis and forecast of SARS epidemic situation after analysis of the complexity and convergence of the GEP. By simulating at computer, it acquires the forecast curve of the epidemic about Shanxi and Beijing. The result of forecast curve shows that the algorithm is rapid and the result is precise.
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Computer Engineering. 2007, 33(04): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2007.04.017This paper focuses on language model——a new kind of model applied in information retrieval. It begins with an introduction to the way of building up such a model through three stages. Some key aspects concerning this model like sort methods, feedback and combination with other factors are represented. And some facts on the application of language model in information retrieval are put forward to prove its efficiency. There is the prospect on its application in IR.
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Computer Engineering. 2007, 33(04): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2007.04.018Web logical domain mining is a pioneer brunch in the filed of Web mining. It emphasizes to find those Web pages, which in the view of Web site master, have intra logic relationship and is not purely text cluster or hyperlink ranking. The definitions of Web site logical domain differ from different applications. After summarizing several kinds of Web logical domain models and the mining algorithm, this paper proposes a model and an algorithm. The experimental results show that the algorithm is stable and adjustable. Its precision is hardly effected by the scale of Web site, language and mirror sites. And its recall will improve as the quantity of Web pages obtained increases.
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Computer Engineering. 2007, 33(04): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2007.04.019Under the background of developing a MIPSX based embedded system IDE, the paper introduces the target system MIPSX, and then analyzes the source codes and work flow of a user friendly, powerful MIPS simulator——SPIM. It illustrates the process of porting SPIM to support MIPSX, especially three key steps, namely syntax analyzing, instruction simulating and binary file reading.
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Computer Engineering. 2007, 33(04): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2007.04.020The combination of Web services and workflow technology is helpful to improve extensibility and interoperability of enterprise application system. An idea of business process management of service-oriented workflow based on coordination theory is presented. Architecture of distributed transaction management framework of service-oriented workflow is introduced.
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Computer Engineering. 2007, 33(04): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2007.04.021Commercial data mining theories are studied. Web based E-commerce operation pattern is defined and its properties are provided. A mapping theorem is proved, in which a “point-to-set” mapping between Web page links and commerce indexes is presented, establishing the relations between the client browsing patterns, monitoring points in Web pages and commerce process. A new data model is proposed to record business activities. And a new incremental mining algorithm is provided to mine associations between sets of commerce indexes in amazingly increasing data set, by improving discovering and pruning part of present association rule mining algorithm. The method is implemented on third part Web based logistics information system. Experiments show that the algorithm is efficient for data set changed frequently. Based on agent technology, ability of tracking and analyzing commerce information in real time is promoted effectively.
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Computer Engineering. 2007, 33(04): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2007.04.022This paper proposes a new approach to modeling user navigation sequences based on Web surfing characteristic. The model can efficiently control its scale and is robust to noise by making use of inverse Gaussian distribution describing the depth of user surfing path and Web popularity characteristic. Experiments show that the model can reduce the effect of noise and not only has lower space complexity and higher prediction accuracy, control the network traffic effectively caused by prefetching.
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Computer Engineering. 2007, 33(04): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2007.04.023Path coverage is a kind of important standard that investigates the sufficiency of software testing, it requires that every branch in a program should be performed at least once. This paper analyses the definition of the DDGRAPH diagram and related concept, improves the method of designing the DDGRAPH diagram and the dominated tree, implied tree, unconstrained arc. Compared with the former method using an actual application case, the improved method can effectively reduce the number of generated paths, so it can use less test cases to find more errors.
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Computer Engineering. 2007, 33(04): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2007.04.024Networked manufacture platforms are used due to their advantages, but new problems come out on how to integrate the existing networked manufacture platforms conveniently. Based on discussing the island problem in networked manufacture platforms and some current integration ways, a grid mode towards integrating networked manufacture platforms is proposed. The integration rules include invariability, expandability and usability. A virtual organization named networked manufactur platform federation is discussed from three aspects: the trust policy, the management pattern and the commercial style. The architecture of integration system is presented as well as four basic grid services, the federation management, the resource management, the authorization mapping and the cost transfer. The handling process of the new integration system is illustrated with an implemented case.
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Computer Engineering. 2007, 33(04): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2007.04.025Because of advances in sensor technology, micro-electro-mechanism system (MEMS), modern network and wireless communication technology, wireless sensor networks (WSN) are designed and developed. Wireless sensor network can be applied to both abominable and military environments. Though analysis of network characteristics in WSN, new architecture of channel access-based multihop cluster (CAMC) network is put forward, and OPNET simulation model is introduced. The simulation results are analyzed.
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Computer Engineering. 2007, 33(04): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2007.04.026As a kind of fixed BWA system, IEEE 802.16d promises to provide the peak data rate of 70Mbps in order to deploy integrated data service with different QoS. To support this wideband feature, the PHY adopts various modulations and FEC technologies including randomization, RS-CC encoding, interleaving, multiple digital modulation, OFDM and the optional space-time coding. There are no accurate results in regard to the performance of all these deployed technologies yet, however, these results is crucial because it lays the basis for the link adaptation technology. A strict simulation of the PHY is conducted and the performance is evaluated, a theoretical performance estimation formula is proposed and validated.
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Computer Engineering. 2007, 33(04): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2007.04.027Packet schedule is the key mechanism for Internet QoS guarantee. This paper describes a new packet schedule algorithm——SFQ+, which introduces the dynamic window-constrained scheme into SFQ. This paper shows the performance analysis of SFQ+ comparing with SFQ and DWCS, and finally offers the future research on the algorithm.
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Computer Engineering. 2007, 33(04): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2007.04.028Virtual reality (VR) is a rapidly developing technology that has wide spectrum industrial and commercial applications. Networked virtual environments (VEs) are of growing interests to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with the manufacturing message specification (MMS) standards so as to achieve a range of integrated manufacturing services into networked VEs over the Internet.
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Computer Engineering. 2007, 33(04): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2007.04.029In order to improve the absolute performance of grid by reducing the resource management cost, some references introduce the method of grid resources matching and task scheduling based on the bidding mechanism, which is a distributed and universal model. The model mainly resolves along with the extension of the grid scale, the increment of the performance will be offset by the increment of management cost in the centralized management method. This paper investigates the simulation program design and its performance simulation according to that model.
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Computer Engineering. 2007, 33(04): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2007.04.030Aiming at the information retrieval and the multi-replica synchronization in distributed and collaborative design systems, an information sharing system based on P2P (peer to peer) structure is presented. The node model, the management scheme and the information retrieval model are given. In order to ensure the exact retrieval and the blind retrieval, an information search method based on distributed hash table and information clustering is given. In order to ensure the distributed multi-replica synchronization, a novel P2P multi-replica synchronization algorithm “peer-to-peer lock” is proposed. The implement method and an instance system are given.
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Computer Engineering. 2007, 33(04): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2007.04.031Web services-based service management architecture is described, and XML-based service management information model and SOAP (simple object access protocol)-based service management protocol are designed and implemented. Through the proposed architecture, services across administrative boundaries can be efficiently managed and service management system can be flexibly configured. Through scoping and filtering specified by XPath expression, efficiently sharing of service management information across domain boundaries can be realized. Through filtering specified by XPath expression, the fine-grained event notifications can be realized. This paper realizes the service management across different management domain.
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Computer Engineering. 2007, 33(04): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2007.04.032This paper discusses the basic theory of the DiffServ algorithm, sets up the simulate model based on the OPNET network simulator. It collects the simulation results by simulating the DiffServ algorithm. From analysis of the results, the effect on the performance of QoS is researched by setting different service level.
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Computer Engineering. 2007, 33(04): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2007.04.033Based on the system architecture and software structure of MPP (mobile position platform), a new dynamic load-balance algorithm is proposed. It bases on dynamic feedback and imports the increment for admitting new request into the load forecast. It dynamically adjusts the dispatching probability according to the remainder process capability of each node. Experiments on the performance of algorithm are taken in MPP in laboratory and the algorithm is compared with Pick-KX algorithm and DFB (Dynamic FeedBack) algorithm in average throughput and average response time. Results of experiments show that the algorithm is better than the other two algorithms under high system loading condition.
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Computer Engineering. 2007, 33(04): 100-101. https://doi.org/10.3969/j.issn.1000-3428.2007.04.034Aiming at the problem that Ad-hoc networks mainly choose the shortcut, from the view of complex adaption system, this paper adds the probabilistic reasoning algorithm to Ad-hoc routing protocol, using probabilistic reasoning for nodes’ adaption to choose the route. It solves the congestion and load distribution problems of Ad-hoc networks, improves performance greatly. Using object oriented modeling technique to emulate this new algorithm based on OMNET++ platform, results show that it reduces delay time, enhances QoS, provides a new mode for the development of Ad-hoc networks routing protocol.
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Computer Engineering. 2007, 33(04): 102-104.Based on active networks and IntServ architecture, a policy-control mechanism based on agent-manager supported by active networks is presented, the policy-control in intermediate nodes can be simplified, the consistence can be kept, and the RPA can be deployed or updated dynamically. And a policy-control method based on sender is provided.
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Computer Engineering. 2007, 33(04): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2007.04.036This article analyses the problem and performance of mobile and hidden terminals of IEEE 802.11 WLAN. Based on that, it presents an adaptive algorithm . The results of simulations prove that the algorithm can improve the performance of mobile and hidden terminals.
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Computer Engineering. 2007, 33(04): 108-109. https://doi.org/10.3969/j.issn.1000-3428.2007.04.037High power consumption is a major drawback of ternary content-addressable memory (TCAM). Based on their configurable property, this paper proposes two-step routing lookup algorithms based on TCAM, which reduces the consumption efficiently. The implementation based on bit-selection is presented and the worst-case analysis is given. At last, the routing table updating algorithm is presented.
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Computer Engineering. 2007, 33(04): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2007.04.038In order to distribute the traffic in reason for MPLS networks, this paper proposes a new kind of strategy and algorithm based on the type length value in constraint route-label distribution protocol for implementing traffic engineering. Considering the attributes of network resource and the attributes of traffic flows synthetically, the strategy can transfer the suited traffic flows of TLV structure in time and enhance the utilization rate of network resources according to the estimation function for certain traffic flows. Furthermore, the validity of the strategy and algorithm is verified by simulation.
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Computer Engineering. 2007, 33(04): 113-114. https://doi.org/10.3969/j.issn.1000-3428.2007.04.039This paper discusses the characteristic of desktop management interface(DMI) architecture, and elaborates the difference between two big management standards architecture (DMI and SNMP), introduces the concept of distributed agent, then proposes the DMI-SNMP Conversion agent model, and carries out the detailed discussion and analysis to this model.
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Computer Engineering. 2007, 33(04): 115-117. https://doi.org/10.3969/j.issn.1000-3428.2007.04.040Basing on in-depth research on the key techniques of network QoS, a user-perceived network performance measurement system (UNPMS) is designed and implemented. In the UNPMS, a detailed introduction to the implementation of UNPMS and its related technologies is given. Experiment results indicate the scalable UNPMS can do the real-time measurement on network performance of ISPs as an end user and it is a bran-new idea to measure and evaluate user-perceived QoS of ISPs。
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Computer Engineering. 2007, 33(04): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2007.04.041This paper introduces the developments of techniques for mobile Ad Hoc network. it introduces characteristics of mobile Ad Hoc network, objects of security and vulnerabilities and so on. It analyzes the primary threats in mobile Ad Hoc network and the structure of the intrusion detection system for mobile Ad Hoc network, also discusses present representative solutions for mobile ad hoc network, and makes a comparison on aspects of decision method, communication machine, detection model, merits and faults. It makes some constructive suggestions on selection of intrusion detection techniques in the mobile Ad Hoc network, also presents the area of the further research in the future.
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Computer Engineering. 2007, 33(04): 121-124. https://doi.org/10.3969/j.issn.1000-3428.2007.04.042This paper proposes a multi-item electronic auction protocol by using the distributed version of ElGamal cipher. It is of high-level security because no auctioneer or trusted third parties is needed in this protocol and the auction outcome is obtained only when all the bidders submit their shares. The scheme is different from other protocols as it can be applied to the case that each bidder only buys one item as well as the case that one buys two or more items. Besides, its computational complexity is small and it is more applicable.
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Computer Engineering. 2007, 33(04): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2007.04.043With the deficiency of global search ability for K-means clustering algorithm, K-means algorithm based on particle swarm optimization (PSO-KM) is proposed. As an evolutionary computation technique based on swarm intelligence particle swarm optimization (PSO) algorithm has high global search ability, the analysis and experiment show PSO-KM could avoid local optima and has relatively good global convergence. Experiment over network connection that records from KDD CUP 1999 data set is implemented to evaluate the proposed method. The results clearly show the outstanding performance of the proposed method.
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Computer Engineering. 2007, 33(04): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2007.04.044This paper proposes an adaptive blind audio watermark technique based on complex cesptrum domain. Watermark is embedded iteratively, and the embedded intensity is controlled by the requirements of the application. A new method to estimate the attacks parameters by using the characteristics of the original audio is proposed. By the estimated parameters the detector can re-obtain the synchronization between embedding process and detection process. The watermark is meaningful audio. The detector adopts the ICA, which can not merely extract but detect the watermark without any information about original audio, watermark, embedding process and attacks. The experimental results show that the proposed watermark technique has a good robustness against audio manipulations.
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Computer Engineering. 2007, 33(04): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2007.04.045The current text watermark algorithms are vulnerable to “formatting attack” and “saving attack”. To solve the problem, a fragile watermark is proposed to protect rich text format file. The algorithm can resist the above two attacks. The watermark will not be lost when some paragraphs embedded watermark is copied to other RTF file. Receiver can extract watermark from a RTF text and detect whether the text is modified or not. Three attack methods aiming at text watermark algorithms are proposed and analyzed. And the design of text watermark algorithm is also introduced in form of pseudo code. The experiments show that fragile watermark can detect such three attacks.
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Computer Engineering. 2007, 33(04): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2007.04.046This paper presents a digital image hiding technology based on chaos systems, it permutes images by chaotic system, then hides the multiple images into one image by using iterative blending based on chaotic system. Simulation results show that the approach is easy to use and safety.
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Computer Engineering. 2007, 33(04): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2007.04.047An intrusion detection model against attacks to B/S data service system is presented. This model consists of two layers, layer one analyzes security-relevant data from different sources and generates pre-alarm conditions, layer two processes such data and makes final decisions. A tree topology is used in the process of server behavior abstract description, consequently generates historical profile with different security related data. Anomaly behaviors among operations are detected through orderly merge and verification with Apriori algorithm based on general sequential pattern (GSP). The experimental results show that the model integrates alarm conditions with alarm contents and has high intrusion detection ratio.
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Computer Engineering. 2007, 33(04): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2007.04.048The security of computer networks plays a strategic role in modern society. This paper applies pattern recognition approach based on classifier selection to intrusion detection and presents a network intrusion detection approach based on static classifier selection. The approach reduces the errors of static classifier selection and improves the detection performance by partitioning every clustering area with a new method，selecting a classifier according to the sub-areas, and combing the nearest neighbor rule. Clustering and selection (CS) is a typical method of static classifier selection. Experiments have been done on the intrusion detection dataset of KDD’99 and the results show that the proposed approach is superior to the one based on clustering and selection.
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Computer Engineering. 2007, 33(04): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2007.04.049This paper proposes a compact and low cost architecture for AES encrypt and decrypt. As the mathematical manipulation lies on finite filed computation, the orders of the round operation are modified so that the design can reuse some modules to save the area. Meanwhile the element inversion in the SubByte module is performed by composite field technique and the area and power consumption is reduced significantly. Based on the HHNEC 0.25μm CMOS technology, area of the design is about 30k equivalent gates and its system frequency will be up to 100MHz. The operation speed of the 128bits data encryption and decryption is as high as 800Mbps.
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Computer Engineering. 2007, 33(04): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2007.04.050The serious information leaked by the pseudo-random sequence generator and the chaotic cipher based on the generator is founded by the analysis. Based on the leaked-information a known-plaintext attack and a related-key attack on the them are proposed which brings out the fact that neither the generator nor the chaotic cipher is safe. On a Pentium 4/2.5GHz personal computer, it takes 48s for the known-plaintext attack on the generator with 64bits key at a success rate 0.75, however, applying the related-key attack, it takes about 39s to recover 64bits key of the generator at a success rate 0.99, furthermore it takes about 2min and 7s to recover the 128bits key of the chaotic cipher at a success rate 0.95.
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Computer Engineering. 2007, 33(04): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2007.04.051Digital watermark is an important security technique that is used widely to protect some key information such as privacy, authority through embedding watermark into the mediator. This paper designs a watermark algorithm according to the principle of the DCT transformation as well as combination with JPEG standard. While making sure of the watermark’s embedding position, this paper takes good use of the sense of visual feature of person and the characteristic of image. The examination of watermark only needs a very small part of data from the original image according to the principle of the algorithm. It can still availably examine the watermark’s esse when the image that contains watermark suffers the compression of the different degree, shearing to slice, and so on.
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Computer Engineering. 2007, 33(04): 152-153. https://doi.org/10.3969/j.issn.1000-3428.2007.04.052This paper brings forward a frangibility blind digital watermark algorithm based on mark strong watermark. It selects three luminance DCT coefficients at random, then embeds watermark information. The result of experiment validates the feasibility of watermark algorithm via distilling the watermark picture directly from the picture embedded in watermark. And also validates the frangibility of watermark algorithm via locally modifying and saving as the picture embedded in watermark. Experimentation shows that this watermark algorithm has good concealmeat and frangibility.
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Computer Engineering. 2007, 33(04): 154-156. https://doi.org/10.3969/j.issn.1000-3428.2007.04.053Secure communication is primary issue between different VO in the grid. A grid secure logical view is presented. The paper introduces the process about how to enhance SOAP message integrity and confidence based on WS Security by associating a detailed application scene on grid. It analyses encryption and decryption, authentication and digital signature, handle technology about SOAP message. A grid security computing platform is given as an instance of SOAP application.
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Computer Engineering. 2007, 33(04): 157-159. https://doi.org/10.3969/j.issn.1000-3428.2007.04.054In nature language processing, the capacity of processing the sentence group becomes more and more important. It is the key to obtain the meaning of a paragraph, a chapter, and even the full text. This paper proposes a method for marking off the Chinese sentence groups based on the semantic relationship between the sentences within the sentence group. The paper also presents some formalized rules for detecting the Chinese sentence group. They are based on the division method and take advantage of the symbolic system of language concept space which is used to express the meaning of a word or a sentence aforetime. The experiment indicates that the method and the rules are good at detecting the Chinese sentence group.
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Computer Engineering. 2007, 33(04): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2007.04.055The rectangle-packing problem often appears in loading, timber cutting, very large scale integration design, etc. Many algorithms such as simulated annealing, genetic algorithm and other heuristic algorithms are proposed to solve it. This paper recommends an efficient greedy algorithm according to ten-thousand-year experience and wisdom of human being. Twenty-one public instances are tested by the algorithm developed. The average trim loss and runtime is 0.28% and 17.86s respectively. Furthermore, 8 instances are achieved optimum solutions. Experimental results demonstrate that the algorithm developed is fairly efficient for solving rectangle-packing problem.
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Computer Engineering. 2007, 33(04): 163-164. https://doi.org/10.3969/j.issn.1000-3428.2007.04.056The paper presents a rapid spatially constrained mixture model for image segmentation. For the spatial constraint, a filtering process is incorporated into the EM algorithm with only a small computational overhead of the standard EM algorithm. Images are down sampled to speed up segmentation process. In order to circumvent the problem of small sample model selection, the proposed spatially constrained model-based clustering method employs a weighted likelihood and assigns weight to each pixel according to the filtering process. The experiments show that the proposed image segmentation method can produce quick and reliable results comparable to the work using the original image size.
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Computer Engineering. 2007, 33(04): 165-167. https://doi.org/10.3969/j.issn.1000-3428.2007.04.057After studying the traditional CBR model, according to the deficiency that the feature weights are subjectively defined, this paper proposes a linear-regression model for CBR retrieval, which will improve the effectiveness of CBR retrieval model. The key idea is to decide the weight of each feature by the method of least square. And its property for linear regression helps to make the weights more exact. Thus in the model the similarity degree between cases is more precise than the traditional one, which facilitates the reuse of the existing cases greatly. It also gives one method to implement the model and describes the parameters.
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Computer Engineering. 2007, 33(04): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2007.04.058Spatial clustering is an important research topic in the spatial data mining(SDM). Classic clustering algorithms ignores the fact that many constraints exit in the real world and can affect the correctness of clustering result. This paper discusses the problem of spatial clustering with obstacles constraints and proposes a novel genetic K-medoids spatial clustering with obstacles constraints based on the genetic algorithm and the K-medoids method. The comparison proves that the method can not only give attention to local constringency and the whole constringency, but also consider the obstacles that exit in the real world and make the clustering result more practice. The experimental results show that it is better than simple genetic algorithm and tradition K-medoids method. The drawback of this method is comparably slower speed in clustering.
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Computer Engineering. 2007, 33(04): 171-172. https://doi.org/10.3969/j.issn.1000-3428.2007.04.059This paper proposes EACSS, an entity structure of the MAS. The design of each module of command-control agent (CCA) is introduced, as well as the function is analyzed. The restriction-reasoning module adopts the fuzzy decision strategy and imitates the process of thought to store and apply information. The performance of EACSS is analyzed. All those help to further study the application of agent for command and control in warfare.
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Computer Engineering. 2007, 33(04): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2007.04.060In order to assist the analysis of vehicle video in ITS, a novel criterion of city vehicle video labeling is proposed. A system is developed based on the criterion. If labeled video is used to train and test video analysis algorithms, it can help researchers to improve and optimize their video analysis algorithms greatly.
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Computer Engineering. 2007, 33(04): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2007.04.061To realize automatic registration of SAR image, an approach of fast match based on patch is proposed. Based on the correct region detection and segmentation, patches are extracted and their geometric features are accurately described, so image is registered by homologous points. Application of the proposed automatic registration model shows that it achieves sub-pixel level results.
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Computer Engineering. 2007, 33(04): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2007.04.062This paper presents the highest speed face detection algorithm——Boosted Cascade face detection algorithm. Since the Boosted Cascade algorithm hasn’t taken the complexion into consider, it sometimes makes mistakes that can be easily solved when adding the complexional information to the algorithm. In order to solve the problems, this paper presents a solution of improving Boosted Cascade algorithm, that is detecting the possible face areas with the Boosted Cascade algorithm, using the model of complexional segmentation to verify the result of recognition. If the degree that the pixels of possible face areas accord with the complexional mode exceeds a certain number, then accept them, or abandon them. The improved algorithm has high detection accuracy, and it can improve the detection efficiency without slowing down the speed.
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Computer Engineering. 2007, 33(04): 182-183. https://doi.org/10.3969/j.issn.1000-3428.2007.04.063Basing on the existing representation models of uncertain information, this paper proposes a kind of temporal knowledge representation model, which could be extended and improved on the problem of interval representation to real events. It also discusses the construction methods of emergency knowledge base and reasoning mechanism. The experimental results show that the prototype using this model and reasoning methods has greater efficiency and better scheme rationality.
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Computer Engineering. 2007, 33(04): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2007.04.064This paper researches on problems of selecting important features and proposes a feature selection method fitting for large data set, selects feature subset using feature similarity, the idea of floating search method, and classifiers with the help of mutual information and accuracy weight, and propose a Bagging-based selective result ensemble algorithm to improve the algorithm stability. Intrusion detection data of KDD Cup’99 to validate the performance of algorithm is introduced.
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Computer Engineering. 2007, 33(04): 187-188. https://doi.org/10.3969/j.issn.1000-3428.2007.04.065The Fourier describer only describes the boundary shape of the planner target region, and can not reflect feature inside characteristic .If the gray distribution of target region is known, one can make use of the gray distribution to describe the target characteristic and boundary shape and get to reflect the affine invariant feature inside characteristic, can reflect the origin characteristic more completely.
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Computer Engineering. 2007, 33(04): 189-192. https://doi.org/10.3969/j.issn.1000-3428.2007.04.066Human not only has the ability of logical reasoning, but also can control and express emotions. Moreover, how to make computers emotional is becoming a more important research area, since computers can reason logically with AI. This paper proposes a new emotion model by combining the personality with the OCC model in a three-dimension emotional space, based on the theory of artificial psychology and basic emotion theory. Then, it realizes a software virtual human, which uses the mentioned model as an affection core. This virtual human can not only study and memory, but also can interact affectively.
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Computer Engineering. 2007, 33(04): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2007.04.067Error recovery in syntax analysis is one of the most important parts of the intelligence in the compiler. The effect of error recovery influences intelligence and syntax analysis. This paper presents a new method of modifying the items of Goto table in correcting syntax error based on analyzing the items of LR syntax analysis table. It uses the leisure items in LR syntax analysis table. It can improve the efficiency and precision in diagnosing and correcting syntax error without requiring more space.
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Computer Engineering. 2007, 33(04): 196-197. https://doi.org/10.3969/j.issn.1000-3428.2007.04.068The width and the gray level of the navigation line keep almost the same in the image. Based on those characters, the navigation line can be detected robustly. Scanning the image alone the horizontal line to find the neighbor edge points whose distance is between the navigation line width minus 2 and the navigation line width multiple 2, and the gray level variance of pixels between them is small. Then the navigation line can be detected from those points by fast Hough transform roughly and refined by least square method. Experiments with real images show that this algorithm can detect the navigation line robustly with high speed.
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Computer Engineering. 2007, 33(04): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2007.04.069An edge detection-projection feature based algorithm to locate the LP and a vertical projection-template matching algorithm to segment the characters are proposed. The edges are detected in a gray-level vehicle image, the result of experiment shows that the speed of detecting license plate is high and the obtained contour is very legible. The LP region is located by projection method, the tilt angle of LP is corrected by Hough transform. The character is segmented by LP segmentation algorithm, and some problems are solved effectively under complex scenes. To demonstrate the effectiveness of the proposed algorithm, it conducts extensive experiments over a large number of real-world vehicle license plates. It reports that the proposed algorithms have high accuracy and robustness.
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Computer Engineering. 2007, 33(04): 201-203. https://doi.org/10.3969/j.issn.1000-3428.2007.04.070An interactive adjusting method of sequential images mosaic is proposed on the basis of graphical user interface, in order to correct the errors of the auto-process. This paper describes the fundamental algorithms of sequential images mosaic. The key problems of interactive technology i.e. coordinate transformation and adjusting match dual-point are also solved. In the experiment section, the efficiency and correctness of the algorithms are validated in terms of the total time spent in sequence images mosaic process.
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Computer Engineering. 2007, 33(04): 204-205. https://doi.org/10.3969/j.issn.1000-3428.2007.04.071This paper proposes a new image compression algorithm, based on dynamic side-match finite-state vector quantization and S+P transformation. The algorithm decomposes the original image by the S+P transform, the correlation of the three directions’ wavelet coefficients is used to construct the band-cross vector, and the vector is quantized by the DSMVQ and PNN. Through the method above, the high coding efficiency and reconstructed image quality are both obtained. Results of the experimentation show that this method can be realized easily and compress the wavelet image efficiently under lower coding rate.
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Computer Engineering. 2007, 33(04): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2007.04.072A new adaptive separating algorithm based on distance-weighted is proposed in this paper. Applying some heuristic rules, it counts the weights of the pixels on form line, then compares each weight with the threshold to judge whether the pixel belongs to character. The weights and the threshold are obtained automatically according to the processing form. The algorithm is independent of the form line detecting methods, and easier to develop. Experiments show that this method can do well with the overlaps easily with high quality, which can improve the accuracy of form recognition.
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Computer Engineering. 2007, 33(04): 209-211. https://doi.org/10.3969/j.issn.1000-3428.2007.04.073This paper introduces a simple and valid automatic container code recognition system based on information fusion. According to the characteristics and distribution rules of container codes, a series of production rules are proposed to divide the codes more properly thus provides more precise information for feature extraction and code classification. In order to get higher correct rate, three neural networks classifiers with three different feature exaction methods are used separately, then the results are fused by D-S evidence theory to get final decision. The system is robust to varying light and shadows and gets satisfied results in experiments.
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Computer Engineering. 2007, 33(04): 212-214. https://doi.org/10.3969/j.issn.1000-3428.2007.04.074This paper studies the properties of different wavelet decomposition coefficients when illumination, pose and expression are changed. Robustness of face recognition is improved by decomposing different coefficient. The standard face database from Harvard, UMIST and Yale are selected to evaluate the recognition accuracy of the method. The experiment indicates that the error rate of the method based on the wavelet transform and SVD is lower than that of the method of singular value decomposition in gray domain.
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Computer Engineering. 2007, 33(04): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2007.04.075Existing service discovery mechanisms based on semantics have limitations. A business user-oriented Web services discovery model is introduced in which domain ontologies and services are managed in different layers by applying ontology clustering methods. The business user-oriented idea is implemented.
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Computer Engineering. 2007, 33(04): 218-219. https://doi.org/10.3969/j.issn.1000-3428.2007.04.076It is hard to get solutions in job shop schedule problem using by single algorithms. This paper proposes a hybrid algorithm for job shop schedule. The ant colony algorithm which plunges the local situation easily is used as a global search algorithm. In addition it proposes taboo search algorithm based on a new neighborhood search method, and the TS algorithms in the method are used as local search algorithm. Because the TS algorithms have the stronger local search ability, and it can overcome the disadvantages of ant colony algorithms, so it gets satisfied solutions for job shop scheduling. The experimental results show that this algorithm can solve typical benchmarks problems efficiently, such as FT10, LA24, LA3 efficiently. The hybrid algorithm gets higher the average agreement compared with TSAB and PGA.
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Computer Engineering. 2007, 33(04): 220-222. https://doi.org/10.3969/j.issn.1000-3428.2007.04.077Through researching on the relevant theory of Rough set, a system of knowledge representation, acquisition, discovery and application is founded. A equipment maintenance support configuration method based on reduction attributes with discrimination matrix is given. The configuration projects of the equipment maintenance support resources are presented on qualitative analyzing of the resources configuration in complex battlefield by an example. It shows that the approach is practical and useful.
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Computer Engineering. 2007, 33(04): 223-224. https://doi.org/10.3969/j.issn.1000-3428.2007.04.078The hill-climbing search through hypothesis space is widespread used in many learning algorithms. It can’t grantee getting the globally optimal solution. In order to reduce the risk of converging to locally optimal hypotheses, beam search approach is explored. But in most of search algorithms, the k candidates with the most high performance measure value are selected. This paper presents some variations of beam search approaches. With these approaches, the k candidates could be selected in more reasonable way that can reduce the risk of converging to locally optimal solution in some extent. The experiments are done on the UCI repository of machine learning databases.
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Computer Engineering. 2007, 33(04): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2007.04.079For a two order polynomial kernel function based support vector classifier, the classifying function can be written in the form of the vector’s components with the similar terms combined. When the support vectors are got, the numerical coefficient of those terms can be calculated. Classifying an unknown class vector by such a classifying function, the calculation between each support vector and the vector to be classified can be avoided, which means that the speed of classification is independent of the number of support vectors. Experiments with real road images show that such a support vector classifier is superior to the neural nets in preciseness for road detection, and the classifying speed can meet the real-time computing need well.
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Computer Engineering. 2007, 33(04): 228-229. https://doi.org/10.3969/j.issn.1000-3428.2007.04.080Scan forest is an efficient architecture which can reduce the test application cost, test power of scan testing and test data greatly. This paper proposes a new seed encoding scheme for CUT with scan forest architecture. Under this scheme, pseudo-random patterns are initially applied to cover the easy-to-detect faults. Test patterns are generated by an ATPG for the remaining faults. For a given seed determined by a generated ATPG pattern, encodes it by the number of clock cycles the LFSR needs to run to reach it. Experimental results show this encoding reduces seed storage by up to 83.3% compared with conventional method.
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Computer Engineering. 2007, 33(04): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2007.04.081This paper researches the implementation methods of the 5Gbps~40Gbps switch technology and IP soft-core. With the design idea of multilayer and modularization, it programs the 40Gbps broad band switch circuit in Verilog HDL. It realizes a versatile, alterable capability, transplantable IP Soft-core of the broad band switch circuit. The IP core can be used in the DXC circuits of the SDH equipment.
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Computer Engineering. 2007, 33(04): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2007.04.082A network data backup model based on hard disk (HDD) and storage area network (SAN) is constructed. The communicating mechanism is discussed, and the backup data is protected by secure socket layer (SSL). The differential backup is implemented in this model.
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Computer Engineering. 2007, 33(04): 236-238. https://doi.org/10.3969/j.issn.1000-3428.2007.04.083The interoperation problem of field device based on Ethernet for plant automation (EPA) and the other field standards is analyzed, and the characteristics of OLE for process control (OPC) are studied. Based on the analysis, OPC server based on EPA is designed and introduced. Furthermore, data-collection of the remote supervised system based on OPC, OPC client, interacts with the OPC server to read data from the field device. The result indicates the practicability of the design.
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Computer Engineering. 2007, 33(04): 239-240. https://doi.org/10.3969/j.issn.1000-3428.2007.04.084In order to enhance the turnover rate and the performance, some NPUs have used the pipeline technology and the hardware multithread technology. Hardware multithreading can effectively hide the delay of accessing memory, and reduce the expenses of thread changing, thus enhance the performance. But the hardware multithread can’t fully eliminate the expenses of thread changing, it still needs to flush and reload the pipeline, this would waste some clock cycles, could not fully take the advantage of using multithread. This paper proposes one new design method, which can reduce this part of expenses, then enhance the performance of processors.
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Computer Engineering. 2007, 33(04): 241-244. https://doi.org/10.3969/j.issn.1000-3428.2007.04.085This paper introduces the main techniques about the design and development of the model of the 3D engraving plotter. The methods of machine geometry modeling and scene optimizing based on the Open Inventor are proposed. It also describes the design of the structure of working object and the interpretation of NC codes for the 3D engraving plotter. It accomplishes the remote control by the socket network programming and implements the smooth video transfer by using the adaptive end-to-end congestion control in this system.
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Computer Engineering. 2007, 33(04): 245-246. https://doi.org/10.3969/j.issn.1000-3428.2007.04.086This paper implements the video compression of image based on the wavelet transform chip ADV611 to solve the data flow problem, and designs Ethernet-PROFIBUS gateway to complete the transportation of data, taking advantage of high speed and high bandwidth of field bus. According to the result of experiment, the given method not only can expand the transmission distance, accelerate the transmission speed, reduce the transmission errors, but also save cost, avoid repeating investment on the premise of guaranteeing the integrality of image data and the high quality of the image.
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Computer Engineering. 2007, 33(04): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2007.04.087A circuit for the high precision and stability drive which uses subdivision technology is described. The circuit mainly uses EPROM and FPGA to constitute the pulse distributor. The circuit adopts the ascending frequency startup to make the stepping motor have a smooth transition from startup state to the working state. The experimental data illustrates that the stepping motor can have high period stability in use of the drive circuit.
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Computer Engineering. 2007, 33(04): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2007.04.088The problem in the computer aided automobile configuration design field has raised more and more attention from researchers in recent years, which is that the low automobile component reuse and the technology of computer aided intelligent design is not satisfying. To tackle this problem, this paper presents a novel idea of supporting reuse in an automobile configuration design system. Moreover, it not only makes preliminary research and application of the design and storage of automobile component, but also the organization, construction and management of component library are concerned according to characteristic of automobile configuration design.
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Computer Engineering. 2007, 33(04): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2007.04.089This paper analyzes general equivalence checking methods, discusses combinational equivalence checking methods, studies characteristics and applications of the methods. At the end of this paper, laws of evolution of combinational equivalence checking are summarized and the direction of study on the combinational equivalence checking is indicated.
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Computer Engineering. 2007, 33(04): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2007.04.090Explicitly parallel instruction computing (EPIC) can decrease the complexity of hardware, and simultaneous multithread(SMT) has the unique ability to exploit TLP(Thread Level Parallelism), so great benefit can be obtained by combining these two techniques. Fetch policies are of great importance to the overall performance of SMT processors. This paper describes several prevailing fetch policies used in superscalar SMT processors, analyses their applicability for EPIC SMT processors, and proposes a novel fetch policy called SICOUNT (Stop ICOUNT) suitable for EPIC SMT. Detailed analysis indicates that SICOUNT strategy can take full advantage of the HW/SW Co-design characteristic of EPIC. It achieves this by taking into account the stop hints generated by EPIC compiler. This makes it easier for SICOUNT to evaluate the flowing speed of each thread more precisely, and to fetch instructions with better quality.
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Computer Engineering. 2007, 33(04): 259-262. https://doi.org/10.3969/j.issn.1000-3428.2007.04.091By development of the digital signal processing theory and improvement of microelectronic technology, using the feature of high speed of FPGA has been the focus of research and exploitation in satisfying real time of digital signals processing in RADAR. Combining scientific research, the paper introduces architecture description of EP1S30 and IDT72V3670 chip, involves configure method. According to the need of project, it discusses the designing and debugging of electrocircuit.
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Computer Engineering. 2007, 33(04): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2007.04.092A component GIS is a component objects based platform for GIS applications development. It provides GIS functions with a group of components that have standard communication interfaces and can be used in multiple languages. Compared with traditional GIS, a component GIS has many advantages, for example, it is easy to integrate with other systems, can be conveniently embedded in multiple developing languages, has high extensibility, and can be easily used to develop a system. It has become a developing trend of GIS. The paper introduces the agroclimatic division system of Guangxi which is based on component GIS, presents the key implementation techniques, the architecture, the main functions of the system, and an example of system application is given.
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Computer Engineering. 2007, 33(04): 266-267. https://doi.org/10.3969/j.issn.1000-3428.2007.04.093Combined with the development of AD driver of S3C2410F board, this paper mainly deals with the building of cross compile environment, components and realization of char drivers under Linux operating system. The debugging and publishing method of drivers is discussed too.
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Computer Engineering. 2007, 33(04): 268-269. https://doi.org/10.3969/j.issn.1000-3428.2007.04.094In order to solve the problem of high-rate and high-reliability data transmitting, to ensure better effect of aviation information system, according to the analysis of real-time OS and airborne information display, this paper implements the airborne real-time and embedded OS, beyond which airborne information display system is finished.
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Computer Engineering. 2007, 33(04): 270-271. https://doi.org/10.3969/j.issn.1000-3428.2007.04.095This paper intends to explore the ways to realize the automatic test tool for retrieving the tested API, generating the test data based on API together with the test case generated and the driving of the execution of test and monitor automatically. In the end, the results and procedures for testing an exact program with the tool are presented.
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Computer Engineering. 2007, 33(04): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2007.04.096The intelligent mobile rack is a kind of modern storage equipment that has a good future of application. This paper introduces a kind of Intelligent mobile rack, which is used in the area of archives storage. The software and hardware design and implementation of the control system are discussed.
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Computer Engineering. 2007, 33(04): 275-276. https://doi.org/10.3969/j.issn.1000-3428.2007.04.097μC/OS-II is a very popular embedded operating system nowadays. With high efficiency to carry out, taking up small space, good performance in real-time and strong expansibility characteristic, it is widely used in the industry controlled field. This article introduces the file system. According to the actual conditions of the embedded system while using, it sets up a file systems progressively.
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Computer Engineering. 2007, 33(04): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2007.04.098A view-dependent multi-level of detail model based on triangle collapse and calculation of volume error is presented. This algorithm uses LOD model to render the 3D scene. LOD model can render the 3D scene with different level of detail and simplify the geometrical data.
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Computer Engineering. 2007, 33(04): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2007.04.099With the development of embedded terminals, an increasing number of users demand friendlier user interface and lower cost graphics system. After analyzing the characteristics of different graphics processing mechanisms, the study on software-based multiple graphics-planes mechanism shows the feasibility of meeting user demand. According to the principles and the architecture of this mechanism, a way of how to blend multiple planes using software is brought forward, and a nice user interface is successfully implemented. The test of the interface style and the memory consumption state show the capability difference between single-plane mechanism and software-based multiple-plane mechanism.
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Computer Engineering. 2007, 33(04): 283-284. https://doi.org/10.3969/j.issn.1000-3428.2007.04.100This article is based on the work over terabit high performance router of national“863”project, brings up the design of 10Gbps linecard address maintenance scheme, and demonstrates that the scheme is effective for 10Gbps-linecard, finally, it supplies an algorithm of address maintenance of linecard. Test indicates that this meets the requirement of 10Gbps linecard.
2024
Volume 50 No 4
Volume 50 No 4
(Started in 1975, Monthly)
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428