05 July 2006, Volume 32 Issue 13
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Computer Engineering. 2006, 32(13): 1-3.It is one of the goals of designing peer-to-peer network to minimizing the resource consumption. The article constructs the abstract load model for cluster-based peer-to-peer network. The dynamism of system is investigated based on the collected data in the experiment. The optimal numbers of clusters are respectively obtained under the circumstances in which nodes have the same capability and in which nodes are heterogeneous and nodes keep arriving and leaving. The optimization can give a judgment for design and construction of peer-to-peer system.
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Computer Engineering. 2006, 32(13): 4-5,17.In online bin packing problem, for the online property of next fit(NF) algorithm, it is used widely. However, NF works according to the item arrival sequence, the resource utility ratio is low. This paper based on the computer communication network, adds repacking scheme to NF algorithm, and presents two new algorithms: the last item repacking and each item repacking. Because of being repacked, some items would be packed into the subsequent bin, hence they are called semi-online algorithms. By means of average-case analysis, the paper finds they perform much better than NF, and almost same to the smart next fit algorithm.
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Computer Engineering. 2006, 32(13): 6-8.An image watermarking method in wavelet domain based on information complementation is presented. According to the characteristics of human visual system, this method embeds watermark into the image's wavelet coefficients of horizontal and vertical sub-bands in a reciprocal order. During the extraction of watermark, a threshold is used to select the information of the tow sub-bands. The experimental results show that the method has a good robustness to resist normal signal processing.
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Computer Engineering. 2006, 32(13): 9-11.
The form recognition algorithms in existence are inefficient, and only can abide tiny broken lines. This paper presents an algorithm based on vertex chain code for form cell rectangle recognition, the algorithm uses region-labeling robot to label the inner border of a form cell to get its vertex chain code, using the characters of the vertex chain code, the algorithm can remove the sawteeth on the form frame line efficiently and restore the form frame lines and get the region of the form cell by searching the vertex chain code of the four angles of the cell. Experiments prove that the algorithm has the advantages of high speed, high robustness and being able to resist broken form frame lines.
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Computer Engineering. 2006, 32(13): 12-14.
There has been growing interests in private concerns for future data mining research. Privacy preserving data mining concentrates on developing accurate models without sharing precise individual data records. This paper addresses basic ideas and solutions for secure data mining over distributed data. An algorithm based on dot product for distributed mining association rules is presented. It also gives a protocol of secure dot product computation which is effective to discover frequent itemsets on vertically partitioned data. It can provide good data privacy.
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Computer Engineering. 2006, 32(13): 15-17.
The traffic volume of BitTorrent is becoming larger and larger with the wide application of BT software in the networks. It is necessary to model and analyze BT traffic, and to evaluate the files of BT system. A downloader model, a seed model, and a file evaluation method of BT system are proposed in this paper. Some BT sharing data are analyzed using the models and the file evaluation method.
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Computer Engineering. 2006, 32(13): 18-19,4.
A new intrusion detection scheme based on the combination of the order and frequency characters of system calls (COFIDS) is proposed. This paper applies a text category algorithm (k-Nearest Neighbor Classifier, kNN) to the proposed intrusion detection scheme. In order to improve the intrusion detection rate, a similarity enhancement factor (SEF) is also presented. The preliminary experimental results demonstrate that the proposed COFIDS can provide obvious improvement in intrusion detection ability. The experiments with COFIDS also show that the proposed scheme has higher ability against to noise in the training data and to intrusion detection false positive rate.
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Computer Engineering. 2006, 32(13): 20-22.Large organizations tend to organize their information resources according to their structures. Such a structure often has many similar sub-structures. Using tradition RBAC to model the access control requirement under such environments will lead to define permissions and roles in each one of these sub-structures. So there has much extra work to manage such an access control system. This paper presents an extended RBAC model. In order to solve the above problem, this model adopts organization structures, defines abstract roles and associates such abstract roles and organization structure units.
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Computer Engineering. 2006, 32(13): 23-25.The chaos related theories are used to analyze the real network traffic about its chaos prediction attributes and the prediction-based IP QoS model and scheme are firstly given. The OPNET-based simulating result shows that the QoS performaces in heavy-load environment are all improved remarkably, comparing with the traditional static QoS configuring and measure-based dynamic QoS setting methods.
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Computer Engineering. 2006, 32(13): 26-28,3.On the basis of a general introduction of queueing systems, the mathematic characteristics of common queueing systems are analyzed, a new event driven algorithm is created and used to simulate M/M/c, M/M/c/N, G/G/c/∞/K, G/G/c/N/K queueing systems based on Java. Finally, the results of simulations are evaluated and lead to the conclusion that the simulation of queueing system based on Java using the new algorithm is fast, accurate and universal.
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Computer Engineering. 2006, 32(13): 29-31.This paper proposes the formal language description of the risk in modern information system, based on the resource distribution rule of a representative information system. It also gives a method to the risk quantitative analysis of an information system, and will be an important reference for the risk quantitative assessment of an information system.
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Computer Engineering. 2006, 32(13): 32-34,3.This paper focuses on terrain visualization service and proposes its service architecture. Meantime we also study on the implemention mechanism, data management and service management in system. Several key problems, such as program design and LOD (level of detail) algorithm, are discussed to improve real-time rendering efficiency under Java environment. Finally, the paper designs and implements a prototype system, which show that the algorithm is practical and efficient.
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Computer Engineering. 2006, 32(13): 35-37.Aiming at the dynamic characteristic of the data directory in distributed and parallel database system (DPDBS), the dynamic arithmetic for whole data directory is put forward. The arithmetic is implemented by embedding the consistency check of whole data directory in the course of database executing, improving the two phase commit protocol, and making use of technology such as recovery, parallel handling, and other technology. The application proves its efficiency.
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Computer Engineering. 2006, 32(13): 38-40.This paper proposes a kahn process network (KPN) based on dynamic service composition model, which aims at reducing unpredictable circumstances and uncooperative cases of services in dynamic composition and improving chances of composition success. KPN and corresponding KPN scheduling strategy are used to model dynamic interactions among services. Dataflow modeling and scheduling strategy are introduced and an application of this dynamic service composition model in composition of a ship information query system is presented.
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Computer Engineering. 2006, 32(13): 41-43.Software metrics is an important method for software qualities, but this paper mainly introduces the analysis of the results for object-oriented software metrics, which is based on classes analysis, inheritance analysis, coupling between object classes analysis, cohesion in methods analysis, complexity analysis and so on, and it analyzes the possiblity of metrics-quota with math knowledge in order to ensure the whole quality of object-oriented software.
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Computer Engineering. 2006, 32(13): 44-46.Based on analysis the model of workflow cooperation, researched communications and cooperated workflow control, this thesis brings forward a workflow cooperation model based on agent service. The model advances some imageries about control mechanism and cooperation environment which is import in workflow cooperation.
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Computer Engineering. 2006, 32(13): 47-48.How to reduce and hide the latency of cache misses is the focus. To get the information of cache references, we often need to run simulators, which is very slow. To overcome this, this paper introduces cache profiling in compile without need of simulator. Similar to value profiling and stride profiling, cache profiling instruments instruct referencing memories, which can improve the speed significantly and only need the support of compiler. The information getting from cache profiling can be used to improve instruction scheduling, software prefetching, generating cache hints and helper threads.
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Computer Engineering. 2006, 32(13): 49-51.In reports system, a mathematical model for reports based on graph theory is designed. Algorithms used by reports are described not only to discover the circular dependency and dependency path but also to automatically recompute the set of cells dependent on a changed cell to solve the problem of circular dependency and automaitically recomopute the changed cells.
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Computer Engineering. 2006, 32(13): 52-54,6.This paper gives introduction to connectable object technology of COM and the recognition of composite events. Then EFL event model, which improves the infrastructure of connectable object technology with advanced features and extensions is described. The model is designed to support the recognition of composite events, and XML-based description of complicated relation of events is adopted in the subscription of composite event. Reflective middleware PURPLE, based on EFL, is reflective middleware architecture. The application of EFL event model in PURPLE during the process of environment detection and self-adaptation is also presented.
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Computer Engineering. 2006, 32(13): 55-57.In the process of software system design, the large system is divided to many subsystems, the subsystems implement its functions, at last subsystems are integrated. This paper provides a kind of method for system integration using windows pipe based on the analysis of Windows pipe system. The method can largely reduce the complexity of the system and improve the robust and maintainability of the system.
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Computer Engineering. 2006, 32(13): 58-60.XSIEQ(XML stream query with immediate evaluation), a kind of XML stream query system, can evaluate predicates immediately and output in time. The design and implementation of XSIEQ are presented. XSIEQ uses a modified pushdown automata technique, and its idea is to convert all XPath expressions into a single NFA, then to attach type label and corresponding index info on NFA state. Accordingly, XSIEQ can quickly decide the opportunity of predicate evaluation and data cache in runtime, and implement immediate processing. In the end, the query performance comparison between XSIEQ and YFilter is given and analyzed.
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Computer Engineering. 2006, 32(13): 61-62.This paper states some new characters of the database systems under the grid environment and analyzes two different database integration modes. It also describes a unified database system’s access framework in the data grid project of the chinese academy of Science and gives the details about how it works.
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Computer Engineering. 2006, 32(13): 63-65.In order to research the most advanced method of model-driven development and apply it to projects to improve quality and efficiency of projects, this paper uses the UML2.0 tool Tau developer of telelogic corporation, which has two powerful functions——model verification and code generation automatically, models and designs a temperature controlling system of some space testing devices, and realizes model verification and code generation automatically.
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Computer Engineering. 2006, 32(13): 66-68.CBSD is being used in embedded software component areas. Now the models focus on the establishment of component multiple frameworks. NFAs(Non Functional Attribute)are vital for the success of software systems. As to remedy the problems inherent in software development, a model has been developed to deal with NFAs. Analysing every sub-attribute that the NFA of a product depends on, the model’s objective is to calculate the NFA-specific requirements. It considers the different extent that the sub-attributes to the NFA value by giving a weight value to each sub-attribute. The model will help to consider design tradeoffs, relate design decisions to NFRs, justify the decisions, and assist defect detection.
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Computer Engineering. 2006, 32(13): 69-70,1.Design pattern and formalizing are two very important aspects of software engineering. This paper discusses formalizing design pattern. It focuses on “Structure” section of each pattern. Based on classes and functions, first, the paper analyses basis relations among classes and relations, and properties of relation. It brings forward a notation of hierarchy construct. As an example, it transforms from structure section of pattern “decorator” into formal description in Z.
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Computer Engineering. 2006, 32(13): 71-73.This article introduces the current status of X86 architecture based paravirtualization technology and full-virtualization technology, especially for hardware assistant virtualization technology, proposes two systemic virtual machines, Denali and XEN, which support the paravirtualization technology. Then it discusses the development of full-virtualization technology. In the meantime, it presents the solution scheme that supports these two technologies, and focuses on the trends of development of virtualization technology and its usage model.
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Computer Engineering. 2006, 32(13): 74-76,7.XML is fast emerging as the standard for data representation and exchange on the World Wide Web, storing and querying XML data becomes more and more important. How to query object-oriented XML data rapidly and exactly is a primary research issue. Indexing techniques are valid methods to the efficiency of XML query processing. This paper achieves a query processing techniques of object-oriented XML data based on the path repository index scheme.
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Computer Engineering. 2006, 32(13): 77-79.To estimate null value in the database is a main task of data-processing, first it gets the cloud models which present the raw nonempty value in the database, then recoves the value with the cloud to replace the null value. The method considers the original data’s distribution sufficiently and can simulate the humans’ behavior, so it can estimate the null value more precisely.
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Computer Engineering. 2006, 32(13): 80-81,9.The idea of time-validity is proposed based on the analysis of characteristics of Web pageviews association rules for personalized recommendation. A model of mining association rules for personalized recommendation. A new interest-measure called time-validity for rules is based on this model, which allows for increasable mining and supports more user-interaction in the optimized rule-mining process.
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Computer Engineering. 2006, 32(13): 82-84.With a general purpose of promoting the research and development of flexible softwares, and based on the summarization of the flexibility study and the analysis of the features of flexible softwares, a new definition of software flexibility is presented. In light of the object-oriented technology and the features and definition, this paper also establishes the model of object-oriented software flexibility. The model consists of four profiles, which are the relative adaptability, ease operability, the response rate and the cost ratio of the software. To evaluate the flexibility more objectively and operable, each profile is further decomposed into a lot of factors and each factor has been defined with its metric methods raised.
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Computer Engineering. 2006, 32(13): 85-87.A framework model for the network concurrent server based on object-oriented communication interface wrapper mechanism to solve the limitations of tradition model for the network concurrent server based on OS API is proposed. This object-oriented communication interface framework model makes use of all kinds of OS API wrapper facade to improve the network concurrent server of heritability, haleness and expansibility.
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Computer Engineering. 2006, 32(13): 88-90.The development of agent technology provides new thinking and solution for the research of programming ICAI, agent platform offers support for construction of agent and communication of agent. This paper designs and implements programming ICAI using JATLite agent platform, explains internal mechanism of JATLite platform and process of agent’s construction in and applies modern teaching technology into the teaching process.
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Computer Engineering. 2006, 32(13): 91-93.Network tomography(NT) is a new measurement and inferring method, which is different from the traditional network internal measurement method, it infers the network attribute or identifies the network topology based on the measurement occurring on the edge of the network, implementing the network measurement in no connection with network constructor and protocol. This paper makes a survey of recent works of the network tomography, which presents the basic concept and key technology of the NT, and discusses research directions and open problems in this area are discussed.
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Computer Engineering. 2006, 32(13): 94-96.A new Internet performance measurement method is proposed. The method is based on monitoring traffic on user terminal; results are given by summarizing measured data from a number of terminals. Analysis shows that 15 terminals can produce accurate results under light network load, and around 1000 terminals needed when network is heavily loaded. A prototype software tool is built and primary test results are presented, the test shows that the proposed method is practical.
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Computer Engineering. 2006, 32(13): 97-99.Grid technology aims to help eliminate isolated island of hardware and software resources, so that users can achieve the sharing and managing of many kinds of resources and easily provide services on the entire grid. Currently, the great challenge from the requirements of many popular grid applications is how to share and manage data resources in grid architecture. This paper introduces the architecture design to realize publishing data resources efficiently in grid environment, and then applies this idea in the implementation of data publishing system for scientific data grid.
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Computer Engineering. 2006, 32(13): 100-102.Rapid promotion is important and frequent for cluster servers. This paper presents a dynamic scalable system reconstruction model based on multi-replica distribution. Then a node dynamic inserting algorithm with a local optimal file transfer and balance policy is proposed. Experimental results show that the proposed method can reduce the cost of file transfers when dynamic node inserting and supporting the scalability of cluster servers effectively.
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Computer Engineering. 2006, 32(13): 103-105,.This paper studies the degree and delay constrained overlay multicasting dynamic routing problem, and proposes a new dynamic adaptable overlay multicasting protocol called OMP, and an arithmetic DDCOMR according to the distributing triggers the reorganization. In the end, the paper calculates the complexity of the arithmetic, and simulates the OMP.
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Computer Engineering. 2006, 32(13): 106-107.Wireless sensor network is expected to have a significant impact on the efficiency of military and civil applications. Current works about wireless sensor networks are focusing on providing specific applications. However, there must be an effective way for Internet users to gain access to the data produced by the wireless sensor networks. With WSN becoming pervasive and ubiquitous, it is important to integrate WSNs with Internet efficiently. In this paper, a novel integrated solution is designed and illustrated. The architecture consists of user agent, register agent, application agent, and resource manager. It focuses on providing flexible, reliable, energy-efficient service for various applications.
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Computer Engineering. 2006, 32(13): 109-110,.The progress of grid computing technology is introduced, in particular, EGEE and LCG architecture. The CPU utilization at the institute of high energy physics is quite low due to separately running of these PC Farms for various experiments. Therefore a campus computing grid is proposed as a solution to the issue of low CPU cycle utilization, it enables to integrate these separately running PC Farms into a grid computing system, so that the utilization of CPU cycle can get improved greatly.
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Computer Engineering. 2006, 32(13): 111-113.This paper proposes a P2P overlay network based replica location mechanism in data grid. It organizes the global replica index nodes which are at the top level of replica location service into a P2P overlay network by Chord in order to achieve load balance and performance improvement. It argues that the proposed mechanism has the following benefits: low query latency, good scalability, reliability and adaptability.
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Computer Engineering. 2006, 32(13): 114-116,.The existing mobile IP handoff scheme has some problems such as more handoff latency, easy to lose packets and poor security. From the point of the motion detection, the key problem of mobile IP handoff, this paper presents and implements an efficient mobile IP handoff scheme which can initiatively predict neighbor mobile IP. It adopts the adaptive initiative predictive algorithm, can predict intelligently according to the network conditions and the movement of the mobile host, and thus a fast and smooth handoff is achieved. Simulation results show that it could effectively solve the above problems, reduce greatly the handoff latency and the counters of handoff, guarantee the packet’s arriving in time, increase the handoff performance of the system, and maintain a better QoS.
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Computer Engineering. 2006, 32(13): 117-119.This paper introduces a new SSO scheme with central management. By avoiding every requirement of resource needs an additional logon, it can save lots of cost. In addition, this scheme simplifies existing schemes and taking account of the compatibility with UPnP. After the first logon, the proposal works well even if the host is offline, which is very suitable for digital home application.
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Computer Engineering. 2006, 32(13): 120-122.Using the theory of resource scheduler in Linux/RK for reference, this article brings forward a real-time network strategy on the basis of an embedded Linux system. It mostly makes modification in the existing RTLinux, paying special attention to the real-time requirements. This paper develops a mini network subsystem, and replants it in the mini RTLinux kernel. With specific kernel threads, it designs multiple channels for the network subsystem, which supports the concurrent schedule. As a result, the real time performance refering to network is improved.
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Computer Engineering. 2006, 32(13): 123-124,.The paper investigates the route policy between ASs, then presents a method that can conduct new policies. On the basis of that, it also presents a method of between AS polices verification based on AS relationships. Through this method it can find out the abnormal prefix advertise to verify the route policies. It takes an experiment for the method between two ASs in AT&T, and the results are good.
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Computer Engineering. 2006, 32(13): 125-127.The method using J2EE security mechanisms to support RBAC is shown in this paper. First, the configuration of J2EE security systems is given in the paper and the algorithm of J2EE authorization decision is designed. Then, the language of J2EE security description is used to define RBAC, and the realization of the requirement of J2EE security service is given. It has achieved the anticipative effect in virtue of deployment and application on the platform of the national science technology infrastructure.
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Computer Engineering. 2006, 32(13): 128-129,.This paper introduces Smith preestimating feedback controlling algorithm to control events QoS level in real-time CORBA event channel by simulating discrete event, to control the event traffic. The results show that using this controlling algorithm to control the performance of the event channel enables it to achieve real communication with high reliability and low delay.
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Computer Engineering. 2006, 32(13): 130-132.
Based on the classical MPLS technology and the characteristic of mobile satellite networks, a MPLS-based mobile satellite system top design, which includes networking concept, protocol stack and system functional blocks, is proposed. At last, the key problem that must be faced in MPLS-based mobile satellite communication networks is analyzed and some resolutions are given.
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Computer Engineering. 2006, 32(13): 133-135,.For transparence computing, it is in demand to share multi-resources in the server clusters, such as CPU, memory, I/O, etc. To the problem that existing algorithms only consider unitary factor and can’t satisfy the new demand perfectly, a dynamic load balancing algorithm based on transparence computing is presented, shortly named LBTC. It denotes and harmonizes multi-resources with load vector. Results from the mean slowdown compare of different methods in different systems executing jobs with different mean memory demand, show that LBTC with an advisably increased complexity can improve respond time and performance, and meet the demand of transparence computing.
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Computer Engineering. 2006, 32(13): 136-138.Because of the difference in computing ability of various mobile devices, there is no enough good system that converts current Web contents into the different size according to the mobile device’s ability. This article introduces a Web content adaptation system based on Web annotation that can generate small pages proper to mobile device’s ability and does not need any changes about original Web. Compared to other adaptation system this system can improve some functions: More proper adaptation to different mobile devices and converting speed and so on.
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Computer Engineering. 2006, 32(13): 139-140,.The purpose of this paper is to describe how to optimize submitting jobs in MPICH through the research on the original submitting job method and thus decrease the communication time and get better communication performance. This paper discusses a new method which is called SBM method for submitting job in MPICH to decrease the startup time and thus to improve communication performance. Indeed the communication time based on the SBM method for job submission is proved experimentally to be much faster than the communication time using a comparable algorithm based on an original method, especially when the number of nodes participated becomes very large.
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Computer Engineering. 2006, 32(13): 141-143.A new general parsing method based on the syntax parsing techniques is proposed for the ABNF-coded protocol messages. Taking the ABNF rule set of the text-message syntax as input, it can automatically parse the protocol messages. The experimental results presented show that the new way is stricter and provides a more general usage compared with the traditional specific methods.
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Computer Engineering. 2006, 32(13): 144-146.A network traffic monitor system based on Netflow is presented, and the components of the system are introduced. An analysis is given on the Netflow-processing module, which is the core part of the system. The design of the Netflow-processing module is based on Twsited, which is an asynchronous event-driven networking framework. Compared to the traditional designs based on procedure or multi-thread, such design can save system resource, avoid complexity caused by multi-thread and gain good throughput under high network traffic.
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Computer Engineering. 2006, 32(13): 147-149.During the transition from IPv4 to IPv6, the communication between pure IPv4 nodes and pure IPv6 nodes is a problem must be solved. The translation gateway based on NAT-PT mechanism is one of solutions for it. The NAT-PT mechanism is thoroughly discussed. A modularized design of the translation gateway based on NAT-PT is brought forward with the application of the netfilter function framework.
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Computer Engineering. 2006, 32(13): 150-152.At first, the problem of large-scale, heterogeneity and high-speed network and the deficiency of distributed network management model are analysed, then technology of distributed network management and P2P are described. In this eondition, P2P-based distributed network management model is proposed, and the management workstation-the most key part of the model is analysed especially. At the end, the security of the model is proposed, and it puts forward the corresponding countermeasure.
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Computer Engineering. 2006, 32(13): 153-155,.As an efficient way to guarantee network security, access authentication has been largely deployed. In order to satisfy the authentication requirements in wireless mobile environment, this paper designs an authentication mechanism based on EAP and Diameter protocol, which can support many authentication method. This authentication mechanism is extensible, and it is easy to manage different authentication processes. This authentication mechanism also performs well in the test environment.
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Computer Engineering. 2006, 32(13): 156-158.A fair blind proxy blind signature scheme with the property of proxy revocation is proposed. For many previous proxy signature schemes, it is difficult for the original signer to revoke securely the proxy power. The proposed scheme comes over this weakness, in which the previous proxy signature can be easily verified after the original signer drawing back the proxy power. In the scheme, the identity of the proxy signer is blind to the original signer, both the original signer’s interests and the proxy signer’s privacy are protected, thus the fairness for the original signer and the proxy signer is well guaranteed. Since the scheme allows the proxy signer use different alias to sign the document in each time, it can be adaptable applied to many practical applications.
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Computer Engineering. 2006, 32(13): 159-160，172.Most previous secret sharing schemes are based on the special access structure of threshold. It assumes that all shadow holders should have the same level of power and security, which can not be carried out. Based on the general access structure, a multi-secret sharing scheme that can deter cheating of the dealer and cheating of any participant is proposed. Compared with the other existing schemes, the proposed scheme has advantages of the general access structure, lower computation and the parallel reconstruction in a secret recovery phase.
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Computer Engineering. 2006, 32(13): 161-163.Intrusion detection technology is an indispensable way to keep the network safe. This paper proposes an intrusion detection system (IDS) framework based on network processor and detecting cluster. The possibility of functioning the distributor by IXP1200 and the key algorithms of the distributor are discussed. The result shows that the distributor can achieve more than 1 000Mbps data-capturing ability, and the load balance policy based on CAM is a satisfying trade-off on protecting the information integrity and reducing computing complexity
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Computer Engineering. 2006, 32(13): 164-165，169.Tunnel technology is the nuclear technology of constructing VPN, but tunnel technologies are not very safe. Once network attackers attack VPN successfully making use of security weakness of tunnel protocols, all safety data transmission making use of VPN technology in the Internet is no longer safe. Then the paper probes into security weakness of two principal tunnel protocols(PPTP and IPSec). By means of analysis the final conclusion is that IPSec protocol is the best and most safe protocol in the IP security protocols. IPSec must be used more extensively along with the use of IPv6.
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Computer Engineering. 2006, 32(13): 166-169.A blind image watermarking algorithm is proposed which is used for copyright protection and tracing. The block HT coefficients are selected as the watermark embedding feature collections, and the tradeoff between the imperceptibility and robustness are achieved by the segments selection under control of the keys and quantization embedding for multi-step. The image watermark is firstly Arnold transformed to enhance the security and robustness. Experimental results show that the proposed algorithm maintains the quality of the original image and is robust to common signal processing operations and geometrical distortions.
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Computer Engineering. 2006, 32(13): 170-172.Peer-to-peer networks need certificate to build trust management and authorization. This paper choose SPKI/SDSI certificate in the P2P network and utilizes distributed Hash table algorithms to implement certificates search and store in the distributed networks. This method is efficient ant robust.
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Computer Engineering. 2006, 32(13): 173-175.Wireless network is becoming more and more popular and prevalent today for its portablity, timely, mobility and convenience. But the security of wireless network is very important too and can not be neglected in application.There are some introductions about wireless network knowledges, drawings of safety projects about solving security of wrieless network,advancing suggestions about hightening of security of wireless network in this article.
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Computer Engineering. 2006, 32(13): 176-178，181.This paper presents a kind of network intrusion deception technology–honeypot system and it’s application to cybersecurity, describes it’s architecture and functionalities. This paper also presents some deployment schemes and application features about honeypot system on enterprise networks. Test results demonstrate that honeypot system can decoy, slower and block network intrusion attacks to sensitive hosts effectively
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Computer Engineering. 2006, 32(13): 179-181.Skype is becoming more popular, and receives more many attention. This paper analyzes Skype’ security feature from the communications security, introduces the process of Skype correspondence keeping secret, discusses the technique details of cryptography, under this foundation analyzes authenticating user and server identities to protect the content transmitted across the P2P network from disclosure by parties other than the peers, analyzes the possibilities of a few familiar attacks, carries on the summary to the Skype correspondence safety, and puts forward some safe items that should notice while using.
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Computer Engineering. 2006, 32(13): 182-184.Most of conference key agreement algorithms operate only when all participants are honest, but do not work when some participants are malicious and attempt to delay or destruct the conference. This paper presents a new conference key agreement algorithm based on the identity-based signature scheme given by Cha and Cheon. Under the Gap Diffie-Hellman assumption, honest participants can agree on a common conference key no matter how many participants are malicious, and passive adversaries get no information about the conference key established by honest participants. Furthermore, the algorithm is efficient, and has flexible structure and high adaptability
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Computer Engineering. 2006, 32(13): 185-186，189.This paper analyzes the principle and mechanism of the Linux startup, and the characters about the hardware encryption card, then through modification the kernel source code, with hardware encryption card, and implements mandatory access control based policy. So a host computer identity authentication system is implemented based on Linux 2.6.x kernel
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Computer Engineering. 2006, 32(13): 187-189.The restoration of composite-frame images degraded by relative motion between a camera and an object is systematically studied in this paper. First, the edge “staircase effect” is eliminated through the displacement vector (i.e. motion extent and direction between two sub-fields) estimation based on a block-matching algorithm; Second, the Wiener filtering is applied to remove the motion blur in each sub-field; Finally, through restoring the blurred images captured by relative linear motion with different speed and distance between a camera and a doorplate mounted in a vehicle, the method is validated.
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Computer Engineering. 2006, 32(13): 190-192.This paper introduces the requirement and system flow of the auto-plotting system, and describes the technique difficulties and solution in three phases, speech gathering, speech recognition and auto plotting. First, adopting the speech auto overlapping technique to decrease wrong separating rate and increase recognition accuracy is presented. Second, by using scoring system, separating speech intelligently, picking up data points to improve plotting accuracy is presented. The system is realized with VC.Net and SQL Server, the recognition accuracy can reach 97%, the plotting accuracy can reach 95%, and it meets the system requirements well
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Computer Engineering. 2006, 32(13): 193-195，208.The algorithm of fingerprint matching based on graph is researched, which is composed of endings and bifurcations. The algorithm is stable according to the matching among the complete graphs composed of endings and bifurcations. The endings and bifurcations in the matching image are divided into different groups. The fingerprint identifies by using group and the template of images matching and it can reduce the complexity of computing effectively. The experimental results show that the proposed algorithm has a good quality and is very applicable even the image of fingerprint is distorted or has a low quality
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Computer Engineering. 2006, 32(13): 196-197，205.Test data generation is one of the major task within the software testing process as well as a bottleneck. As an effective search algorithm, genetic algorithm has been used for test data generation in many automatic testing processes recently. Considering the characteristics of DBMS source code and the genetic algorithm, this paper proposes an improved genetic algorithm for multiple test data generation for multiple path coverage, based on bit weight and neighborhood influence. Experimental results show that this algorithm is effective
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Computer Engineering. 2006, 32(13): 198-199，202.This paper proposes a new method for linear features extraction and orientation in images, which overcomes the local nature of the conventional line segment grouping approach, while retaining most of its advantages. It tracks edge points, approximates them to piecewise segments using the iterative endpoint fit-and-split algorithm, and groups the discrete line segments from global view. Finally, the paper gives two means for line fitting. The experimental results show that this method has a perfect performance and is suitable to a wide range of real images.
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Computer Engineering. 2006, 32(13): 200-202.In images measurement and precision of position, the Hough transformation is a general method to extract the edge characters of the image. Based on the Hough transformation, a new automatic detection approach, which is better at the studies on regular grid extraction in spatial cubes and further on spatial coordinate extraction of grid points, is proposed in this paper. By using improved Hough transform, the lines in the image and their parameters can be steadily determined. Point of intersection caused by intersect of two neighboring lines then can be obtained more accurately and with insensitive to noise. The results indicate that the algorithm to calculate the locations of point of intersection given in this paper is valid and mean-root-square error of point of intersection achieves sub-pixel.
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Computer Engineering. 2006, 32(13): 206-208.Niche genetic algorithm is superior to genetic in multiple hump function optimization. However, there is lack of theory to determine theparameter of niche distance, so the algorithm’s application is limited. This paper presents a new approach to determine the niche distance parameter, which is based on genetic algorithm. According to the information of multiple hump object function, genetic algorithm is used to seek several global optimums, whose Euclidean distances are calculated. The niche distance is determined by the minimal Euclidean distance. This approach is successfully used in Shubert function optimization and six-hump camel back function optimization.
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Computer Engineering. 2006, 32(13): 209-211.This paper describes a full-automatic pattern recognizing and tracing system based on neural network. After picking up their vectors by the MOD arithmetic, it classifies the patterns of the mobile objects according to neural network theory. The paper meanwhile gives the experimental result of auto recognizing and tracing process for multi-objects moving under complicated background.
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Computer Engineering. 2006, 32(13): 212-214.This paper presents a platform of generating domain ontology automatically, namely OntoAGS. In OntoAGS, terms are extracted from collected corpus relevant to specified domain, redundant terms are filtered by using corpus irrelevant to specified domain, concept learning methods are employed to identify the meanings of the extracted terms, and instances of learned concepts and relationship between concepts are discovered by using improved instance learning algorithm and relation learning algorithm respectively. Experiments show that OntoAGS outperforms the existing platform TextToOnto by using the above technologies
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Computer Engineering. 2006, 32(13): 215-216，219.This paper discusses the problem of network devices management on Internet, proposes a video transcode system based on software VLC in SNMP under Linux environment. The system implements MIB extending of agent application in VLC board and designs the network management application, in terms of user’s requirements and function offered by VLC board. The test experiment shows that the scheme is effective.
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Computer Engineering. 2006, 32(13): 217-219.CG reflecting model has been a major research topic for a long time now. Realistically simulating has proven very difficult, due to the inherent complexity of the physical processes involved. Most photorealistic solutions use a form of real-time ray tracing and complex differential triangle quantities in big topograph. Unfortunately, such accurate approaches often take many hours of render time per frame. With the advance of programmable 3D hardware, the article discusses methods such as per pixel bump mapping. It is not accurate, but convincing to the human eye. And, it is pretty appropriate to interactive contexts such as video games, simulation and so on.
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Computer Engineering. 2006, 32(13): 220-221，224.The scalable video coder is desired in a multi-resolution environment, which can provide the users with video streams with various quality. But in a spatial scalable encoder, the blocking effect caused by the BDCT used in the base layer can disturb the prediction result in the enhancement layer, which will decrease the encoding efficiency. Thus if a daglocking filter is implemented to smooth the reconstructed image, the bad effect is removed. This paper applies an efficient wavelet-based soft-threshold deblocking algorithm to the spatial scalable video encoder for eliminating the blocking effect and performances a simulation. The result shows the significant efficiency.
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Computer Engineering. 2006, 32(13): 222-224.System development based on the multi-agent platform, has become this crucial problem in the application of multi-agent technology. Through the option of development platform, this paper presents the multi-agent diagnostics and supervisory system based on JADE in precision centrifuge. Then diagnosis agent model, diagnosis mechanism and the ACL communication language are discussed. This system can complete diagnosis task, and reaches the property index of requirement.
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Computer Engineering. 2006, 32(13): 225-227.This paper presents a control flow oriented software/hardware co-design method and procedure, which are based on event management. With this method, the USB2.0 host controller in system-on-chip (SOC) system is designed, and the modules of scheduler unit in hardware are analyzed. The verilog hardware-description language (HDL) in resistor transistor logic (RTL) level of these modules is compiled with synopsis’s design compiler in 0.18μm CMOS technology. Compared with other similar designs, it is shown that this hardware/software co-design method can raise the potential quality and shorten the development duration of SoC chips, especially for protocol application.
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Computer Engineering. 2006, 32(13): 228-230，245.To resolve the aerospace environment numerical simulation problems, such as the calculation model singularity, the bad program transplant, unsatisfactory adaptability, this paper advanceds the COM-based simulation toolkit (SESTK) that is fit for user expanding. Based on the OO(Object-Orientation) method and COM, it uses UML to design system and function, integrates and normalizes the dispersive kinds of space environment numerical models that run in the different system. And it collects the space environment elements calculation models, the correlation program, the expanding data and the sun-magnetic index database. It affords the well using and expanding interface in order to integrate with other simulation software.
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Computer Engineering. 2006, 32(13): 231-233，239.By analyzing research object and simulation process of equipment battle damage simulation (EBDS), the new way to research EBDS is raised to solve the problems in recent (EBDS) research, and the way is to design and implement a distributed EBDS platform. The technology project and development environment for this platform are given, the object model and execution logical structure are designed, and the time management mechanism is established. So the distributed EBDS platform is implemented, the simulation efficiency is improved effectively by federates executing simulation task parallel in this platform, and the system reusability is improved too by HLA object model design.
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Computer Engineering. 2006, 32(13): 234-236.Because of behindhand status of measurement skill used in Shunde South natural gas transporting station pipeline, this paper puts forward a monitor system, which writes the script file based on MCGS configuration software, accomplishment the calculating and compensating, measuring separately of every measuring spot, concentrated inquiring and management of the flux. By doing so, it can be realized the auto detecion and account of spot condition, auto creating report forms, and then, the measurement precision and the utilization rate of natural gas has been improved, it is convenient for the management of natural gas producing .
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Computer Engineering. 2006, 32(13): 237-239.The aggregated equipment support CGF system improves the complexity and fidelity of the equipment support simulation training system based on distributed battlefield environment, which is the important part of the equipment support simulation training system. Based on the analysis of the basic structure of aggregated CGF system, the paper presents the structure of aggregated equipment support CGF system based on multi-agent, and discusses the system operation process theoretically
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Computer Engineering. 2006, 32(13): 240-242.This paper presents a novel approach using non-hierarchical distributed MAS in urban intersection traffic signal control. It is called traffic signal control system based non-hierarchical MAS (TSCSNHM). In the model, each agent plans pattern of signals according to it local traffic status for the intersection it responds. But the patterns must be negotiated with neighboring agents before being implemented. By this means, bigger area effectively control can be achieved. It uses a simulator to validate the idea. This simulator is programmed by Java, and uses KQML to implement communication and negotiation between agents. To contrast with the approach, this paper uses other two typical control methods, fixed-phase control model and centralized control model in simulation. The results of simulation show that TSCSNHM has excellent performance that is closed to centralized control model, and is more simple, flexible and robust than the latter.
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Computer Engineering. 2006, 32(13): 243-245.This paper discusses how to design and establish soil and water conservation information system for small watersheds based on component GIS technology. It discusses combination modes of GIS and soil and water conservation, the design of framework, functions and database of the system. It also establishes the system using Delphi and ArcGIS engine with a case of Liudaogou small watershed in the loess Plateau as an example. This GIS system can input, manage and output spatial data and attribute data about soil and water conservation of small watershed and provide interesting information with texts, tables, maps, aerial photo and other formats.
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Computer Engineering. 2006, 32(13): 246-247，279.A trusted computer system is based on the common computer by researching the embedded system. In the system, a security card is embedded on the motherboard, and the kernel of Linux is modified and improved. The trusted computer has good security and scalability, which can be used in many areas.>School of Computer, Wuhan University, Wuhan 430072
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Computer Engineering. 2006, 32(13): 248-250，253.This article introduces a kind of localization device combined with the pulse encoder and GPS. This device can be used for orienting the accurate trends to the mobile. Compared with the existing technology, it utilizes the cooperation of GPS and pulse encoder to orient the high-accuracy trends, reaches the localization precision less than centimeters, and in a situation that GPS data are invalid, it can still meet the precision request, this device is extensively suitable for high accurate localization of movement body.
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Computer Engineering. 2006, 32(13): 251-253.Enterprise service bus provides the enterprises a reliable, standard-based, distributed and scalable integration platform quickly in low cost which absorbs the ideas of Web service and service-oriented architecture and adopts common and general industrial standards, it pays attention to the future of the enterprises and protects the existing investment.
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Computer Engineering. 2006, 32(13): 254-256，268.In practice, it is common that several members collaborate to prepare a document. For example, in the domain of construction, it is necessary to collaborate with others to prepare investment proposals, feasibility analysis reports etc. But little software for document preparation support this process well up to now. Accordingly, the paper proposes a solution for developing a general purpose collaborative system for document preparation based on network and commonly used word processing software. A prototype system has been implemented. It provides a new approach to developing a collaborative system for document preparation.
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Computer Engineering. 2006, 32(13): 257-259.Aiming at the shortage of the traditional method of embedded system upgrade, a project of embedded system online upgrade based on TFFS is put forward. The operation core, application and bootRom can be online upgraded from remote host without ICE. First of all, the whole project is described, secondly, some key techniques, such as the TFFS file system, the design of the start flow and system backup are discussed, then the realization of the project is discussed in detail, the reliability is designed at last. This project is implemented and verified in the embedded AFTN gateway system.
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Computer Engineering. 2006, 32(13): 260-262.This paper uses semantic Web to implement sharing of GIS. Because WSDL only has interface of service, user can not choose which service fits him when there are several services. This technology adds semantic part into WSDL, and when user looks for a service, it compares each WSDL with user’s profile ontology. It uses schema-graph to implement comparing between WSDL and OWL, by this way, integrates ontology to grid.
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Computer Engineering. 2006, 32(13): 263-265，271.Based on the theories of decision tree, this paper gets the importance assessment value among attributes through applying information gain and constructing formula. Combined with decision tree mining, this paper gets credit risk assessment for individual housing loan, which has highly predictive accuracy when it has been tested and evaluated. This model can be used to help employees of banks to analyze housing loan and can help loan department to make correct credit decision. Meanwhile, the methods using in this paper can be referred to construct other assessment models.
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Computer Engineering. 2006, 32(13): 266-268.This paper introduces two kinds of block cipher briefly: DES algorithm and Rijndael algorithm, implements these two algorithms on embedded microprocessor ARM by several means respectively, and compares their efficiency. The experimental results show that two algorithms work well.
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Computer Engineering. 2006, 32(13): 269-271.Taking design and realization of the inquiring system of geographic information in Shanghai as an example, the paper discusses how topractice the secondary development of GIS using a developmental mode, which is combination of the GIS control with object-oriented programminglanguage. The choice of developmental mode, the main structure and the design of database etc of building the system are illustrated, some functionof the system and method of realization are briefly introduced as well in the paper.
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Computer Engineering. 2006, 32(13): 272-273，276.Nowadays, the development of RFID technology plays a more important role especially its widely application in logistics and warehouse, merchandise anti-counterfeit, communications and transportation, medical treatment and hygiene, national defense and military, etc. However, due to the expensive cost and high complexity of RFID device integration into enterprise background system (for instance: SCM system, ERP system), the popularization of RFID technology has been restricted; in this case, RFID middleware turns out to be a good solution, which in practice have accelerated the widely-using of RFID technology. Based on the components and characteristics of the RFID technology, the paper develops the RFID middleware architecture; then demonstrates a design method for warehouse management system based on the IBM RFID middleware.
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Computer Engineering. 2006, 32(13): 274-276.This article describes the USB driver module and structure under WinCE.Net, and shows an example of developing USB Camera driverby using stream interface driver model. The essential function that should be involved in the USB drive and its transfer form in the application are also analyzed. The design has been proved to be correct by the successful result.
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Computer Engineering. 2006, 32(13): 277-279.The paper describes an approach of unified identity authorization, solving the problem of separate identity authorization when a user logs in different Web application systems. It takes IE plug-in approach, captures user’s post data when first time logging in some Web application system and stores the data into database. When the user logs in this Web application system against, it automatically distills posted data from database, thus eliminates user’s manual identity authorization, and realizes unified identity authorization
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Computer Engineering. 2006, 32(13): 280-282.Intrusion detection system is one of the dynamic defensive techniques, but current intrusion detection systems (IDSs) usually generate a large amount of false alerts and none of them can capture the logical steps or strategies behind the attacks. As a result, it is difficult for human users to understand the intrusions behind the alerts and take appropriate actions. This paper presents a correlation analysis approach based on the sequences and heuristic arithmetic to address these issues after analyzing large numbers of attack techniques and designs a correlation analysis engine for security incident and conducts one experiment to demonstrate the potential of the system, in reducing false alerts and uncovering attack strategies.
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Computer Engineering. 2006, 32(13): 283-286.An integrated GIS solution is put forward based on an overall consideration of produce of solid waste, transport of solid waste, thedecision of solid waste, the quantitative assessment of solid waste, in which, the classical gray model GM(1,1) method is applied to make predictionof solid waste and the GIS components model is used to improve special capability of expression and analysis, providing a decision support forprediction assessment and control of solid waste.
2025
Volume 51 No 6
Volume 51 No 6
(Started in 1975, Monthly)
Superintended by:
China Electronics Technology Group Corporation
Sponsored by：
East-China Institute of Computer Technology
Shanghai Computer Society
Edited & Published by：
Editorial Office 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
Superintended by:
China Electronics Technology Group Corporation
Sponsored by：
East-China Institute of Computer Technology
Shanghai Computer Society
Edited & Published by：
Editorial Office 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