20 June 2007, Volume 33 Issue 12
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Computer Engineering. 2007, 33(12): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2007.12.001There are lots of complex security problems in the cryptographic protocols in lots of runs, which are not different from one run. The objects of formal analysis for cryptographic protocols in a concurrent way include the two ones: a cryptographic protocol in lots of runs and cryptographic protocols in a concurrent way. The above-mentioned objects are provided with the unified formal model. The event graph model is introduced based on the extended model of strand space and Spi calculus. It is a formal model for proving the safety properties of the cryptographic protocols in a concurrent way correctly. The meta-graph is a unit for composing event graphs. It meets all the restrictions in the communication and causal predecessor relation between events, and in the freshness of terms. The prefix, parallel composition, and choice operation among events and meta-graphs respectively are defined, and the meta-graph-based algorithms for composing event graphs are proposed.
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Computer Engineering. 2007, 33(12): 4-6,9. https://doi.org/10.3969/j.issn.1000-3428.2007.12.002This article analyses the key aspects of the data exchange platform functions which is restricted and the possible solutions. The domain marking and domain relations model are established and formalized. The credible data exchange model framework based on domain markings and relations is designed. In the implementation part, the paper proposes the infrastructure to expand the single-exchange model, and presents the solution of the two key questions, global analysis organization and domain marking analysis.
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Computer Engineering. 2007, 33(12): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2007.12.003In order to improve watermark capability, this paper proposes a digital watermarking method based on watermark technique of blocked transformation and quantization. With the aim of improving transparence of the embedded watermark, rows and columns of the watermark image are rearranged in this method. Then the optimized watermark embedding turned to be a two-sided permutation Procrustes problem. And the problem can get a local optimized solution via an iteration method presented in this paper. Experimental results show that this algorithm can improve transparence, robustness, visualization and security of the watermark.
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Computer Engineering. 2007, 33(12): 10-11,1. https://doi.org/10.3969/j.issn.1000-3428.2007.12.004All of the existing ElGamal type broadcasting digital multisignature schemes have a problem: Data should be exchanged many times among signers to get the same signature parameter which would lead to high communication and insecurity. A new sequential multisignature scheme based on discrete logarithm problem without the mentioned problem is proposed. The new scheme is applicable and secure.
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Computer Engineering. 2007, 33(12): 12-15. https://doi.org/10.3969/j.issn.1000-3428.2007.12.005This paper presents an improved quadric error metric edge-collapse based algorithm which can keep the speed and efficiency of quadric error metric and reserve more important shape features even after performing drastic level of simplification. It defines an important degree of a triangle and embeds it into the original Garland’s quadric error metric, so that the metric can not only measure distance error but also reflect geometric variations of local surface. The experimental results show that the new algorithm can reserve quite a number of important shape features and reduce visual distortion effectively at low levels of detail.
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Computer Engineering. 2007, 33(12): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2007.12.006Taking community structure as measurement index for feature selection, a new feature selection measure approach based on modularity coefficient community structure is proposed. Artificial immune network is a type of competitive learning algorithm which is capable of extracting relevant features contained in dataset. It uses the “internal image” memory network to eliminate data redundancy and feature extraction. The new approach is used to analyze the community structure between the input pattern (antigen) and memory network. Experiment study shows the newly approach is proved reasonable and viable.
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Computer Engineering. 2007, 33(12): 19-21,2. https://doi.org/10.3969/j.issn.1000-3428.2007.12.007A method based on local grey-level probability analysis and orientation information measurement is presented to detect dim targets in IR images. Local grey-level probability is computed and used to remove the slowly-changing background and weak edges on the bases of threshold segmentation, as a result, the remaining image composed of strong edge points, noise points and targets is obtained. The difference of the orientation information at the points of the remaining images is utilized to remove the strong edge points. True targets are separated from noise points by multi-frames cumulating. Simulation results indicate that this approach can reduce the number of possible targets and detect small moving IR targets in complex natural background with high efficiency and veracity. It can be used in real-time and multi-targets detection.
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Computer Engineering. 2007, 33(12): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2007.12.008Error reconciliation is a necessary step for quantum key distribution process. The efficiency and the correction ability of error reconciliation procedures are analyzed and estimated, and it gives some expressions about it. The experiment results indicate that it can easily eliminate all errors when the error rate is at 11%.
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Computer Engineering. 2007, 33(12): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2007.12.0092D DCT transform is frequently used in video compression protocol H.264 and MPEG family standards. Conventional operations in general-purpose processors can not meet the demand of the real-time CODEC. A fast implementation of 2D DCT transform is presented and the data structure is designed for the demand. It can make full use of the operations of media instructions, and avoid the data hazard. The performance results show that it can meet the real-time requirement and can be served as a reference for compiler development on media instructions.
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Computer Engineering. 2007, 33(12): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2007.12.010BCE algorithm and its processes of backward schedule and forward schedule are analyzed. Two backward schedule algorithms, RMF and EDFF, and three forward schedule algorithms, RMB, DMB and EDFB, are researched. The cooperation between backward schedule and forward schedule is put forward. Different schedule algorithms are simulated with BCE algorithm. Since EDFF forward schedule algorithm cooperates well with three backward schedule algorithms, it gets better schedule performance than RMF. Simulation results also show that three backward schedule algorithms have similar effect on BCE algorithm. The conclusion that the combination of EDFF and RMB, or DMB, is more applicable for software fault-tolerant module is made.
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Computer Engineering. 2007, 33(12): 31-33,3. https://doi.org/10.3969/j.issn.1000-3428.2007.12.011The transformation from platform independent models (PIMs) to platform specific models (PSMs) is a key technology in OMG’s model driven architecture. But there is no effective solution until now. Based on abstract algebra theory, an architecture-mapping based model transformation approach considering about both the syntax and the semantic characteristics of modeling elements is proposed from the viewpoint of software engineering implementation. This approach makes better use of traceable links established by software architecture between the phases of software lifecycle, and it can be used to support automated transformation from PIMs to PSMs. Software architecture becomes the basis of system analysis and model transformation at the same time. J2EE is used as a target platform to help interpreting the process of using this approach.
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Computer Engineering. 2007, 33(12): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2007.12.012The buffersize is an essential part of a high performance router design. The common method of buffersize computation is based on Poisson traffic model. This method is not in conformity to the actual traffic characteristic and it will cause high rate of packet loss. The proposed fractional Alpha traffic model can denote the characteristic of self-similar and non-Gaussian. The residual distribution function (RDF) based on the fractional Alpha model fit the real traffic better than the RDF based on other models. Based on the new RDF, a method for computing the buffersize is got and used in the high performance router design. The method is simple and the result is satisfying.
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Computer Engineering. 2007, 33(12): 37-39，4. https://doi.org/10.3969/j.issn.1000-3428.2007.12.013Inspired by principles of the human immune system, a family-gene based model for network access control, referred to as FBAC, is proposed. With the concepts and formal definitions of network-family, family-gene, and gene-certificate of FBAC presented, the bionic mechanisms of gene-assignment, family-rule constitution, and gene-signature for gene-certificate generation are established. The algorithms of network- family construction and family-gene based access control are described. The access control problems, which result from the penetration of conventional authentication mechanisms, are solved, and the defect of ambiguity of subject information in X.509 certificates is overcome. FBAC has a better safety and efficiency than the traditional techniques. It provides an effective novel solution to network security.
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Computer Engineering. 2007, 33(12): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2007.12.014The paper proposes an alarm correlation model based on Bayesian networks among communication networks. It adopts EM algorithm to learn the hidden variables in Bayesian networks. The basic concepts of Bayesian networks are introduced. Thhe paper presents a hierarchical architecture for large communication networks. The fault propagation model is used to model the functional relationship among the sub-networks. The paper also discusses how to construct Bayesian networks from the fault propagation model. According to SDH over DWDM experimental systems, the realization and results of the Bayesian learning are discussed.
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Computer Engineering. 2007, 33(12): 43-45,4. https://doi.org/10.3969/j.issn.1000-3428.2007.12.015A packet filter is a programmable selection criterion for classifying or selecting packets from a packet stream. The BSD packet filter(BPF) is a kernel facility in BSD Unix that gives the user-level programs access to raw or unprocessed network traffic. This paper describes the architecture of BPF, analysis the filter model based on directed acyclic control flow graph。The problem of redundant instructions is a crucial problem in pseudo-machine’s code generator which affects the filter’s performance greatly. To solve this problem, the SSA form, combined with redundant predicate elimination and peephole optimization technology, is used to minimize the average path length in the control flow graph. This results in efficient performance improvement.
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Computer Engineering. 2007, 33(12): 46-48. https://doi.org/10.3969/j.issn.1000-3428.2007.12.016The criteria on nonlinear inverse diffusion image enhancement algorithm is put forward and suitable diffusion coefficient is proposed with cube-spine interpolation. Then the good image enhancement results are obtained. The experiments show that the algorithm can enhance images with low noise and preserve detailed textures. The diffusion coefficient complies with the criteria on inverse diffusion image enhancement and is easy to be interpolated.
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Computer Engineering. 2007, 33(12): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2007.12.017This paper proposes a 2D grid graph based image mosaicing method for large-scale microscopic images. It uses 2D grid graph to represent the neighborhood relations of microscopic images, and modify the gird graph to eliminate the effect of blank areas according to the reliability of local alignment. It constructs the global alignment model with all the overlapping image pairs. It adds system skew rectification to global alignment model as the constrained condition. This paper gets globally consistent estimation of alignment parameters with nonlinear optimize method, and succeeds in the automatic mosaic construction of large-scale microscopic images.
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Computer Engineering. 2007, 33(12): 52-53,5. https://doi.org/10.3969/j.issn.1000-3428.2007.12.018
The kernel and its parameters in support vector machine are important, an effect method for determining the parameter of Gaussian kernel based on the distances among the support vectors is proposed. The characters that the optimal discriminative function is determined by the support vectors, and the support vectors are centered as the Gaussian function, are considered in the method. Experimental results show that the method exhibits the essence of image feature space and solves a difficult problem for the parameter of Gaussian kernel in application.
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Computer Engineering. 2007, 33(12): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2007.12.019This paper considers the problem of buffer and channel optimal transmission with ARQ over fading channels. The objective is to vary the transmission power and rate according to the buffer and channel conditions so that the long-term system throughput is maximized under some average transmission power constraint. It formulates this optimization problem as a Markov decision process (MDP) and uses dynamic programming techniques to obtain the solution.
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Computer Engineering. 2007, 33(12): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2007.12.020Load balancing for service deployment in next generation network (NGN) should consider that the consumption of resources is caused by services themselves and service correlations. Aiming at the characters above, a recursive optimization algorithm is presented. It realizes load balancing for heterogeneous system while reducing the consumption of resources due to service correlations. The algorithm is proved to be effective by simulating tests.
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Computer Engineering. 2007, 33(12): 60-62,7. https://doi.org/10.3969/j.issn.1000-3428.2007.12.021Consistency is the basic problem in distributed virtual environment(DVE). After analyzing the causes and results of inconsistency in DVE, a series of solutions to consistency problems is presented. These solutions include using Object-Property-Event (OPE) mechanism in 哦object-oriented method to solve the entity-state consistency problem, using software clock synchronization to solve time consistency problem, and using coordinate transformation to solve space consistency problem. An event ordering algorithm based on callback lag is also presented in order to solve order consistency problem in processing event. These solutions are applied in synthetic simulation environment (SSE), which is a distributed interactive simulation system. The result of system execution shows that these solutions can effectively solve consistency problems in DVE.
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Computer Engineering. 2007, 33(12): 63-64,6. https://doi.org/10.3969/j.issn.1000-3428.2007.12.022This paper presents a data mining algorithm based on fuzzy neural network (FNN). Using fuzzy theory and neural network to structure and train fuzzy neural network, the algorithm overcomes the shortcomings of neural network such as complex structure, long training time and lack of understandable representation of results. Establishment and training of fuzzy neural network which meet the precision requests realize the utilization fuzzy neural network method to withdraw the knowledge from the database.
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Computer Engineering. 2007, 33(12): 65-67. https://doi.org/10.3969/j.issn.1000-3428.2007.12.023Since logistics resources on Internet are distributed and autonomous, their structures and interface are different. To mine global information in logistics resource-grid environment, a new grid-oriented data-mining model is provided without the same structure between grid resources. It is based on grid, agent and incremental data mining technology. Web-based logistics resource grid system is analyzed and resource-grid system is divided into logistics domains for easy management. Dynamic resource mining algorithm for a domain and request-based mining algorithm among domains are designed to resolve the data-mining problem among heterogeneous systems. Mining efficiency among domains is promoted with incremental data mining technology.
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Computer Engineering. 2007, 33(12): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2007.12.024Flash memory is becoming increasingly popular, however, finite erase cycles shortens lifetime of flash greatly. Flash file system must employ certain strategy to prolong lifetime of flash, and to promote efficiency of flash. This paper analyzes principle for achieving the above purpose in TrueFFS, introduces the method of implementing TrueFFS on flash, analyzes and compares the performance of TrueFFS.
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Computer Engineering. 2007, 33(12): 71-72,7. https://doi.org/10.3969/j.issn.1000-3428.2007.12.025Based on introduction to the P2P technology and Linux kernel Netfilter framework, this paper brings forward the methods, namely, port recognition method and condition code recognition method to identify P2P network packets. It introduces condition code recognition method and discusses how to get P2P condition codes and lists some known condition codes. It also introduces how to identify and manage P2P by Netfilter framework, and gives a brief analysis and summary.
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Computer Engineering. 2007, 33(12): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2007.12.026A data management scheme of solid sate recorder (SSR) is introduced to meet the requirements of spacecraft. The SSR is based on NAND FLASH memory, with bus-width expansion and pipeline technique. The message of each cluster is loaded in the spare area, following the target datum, to keep the pipeline sequence of multiple clusters’ loading, which guarantees the average input speed of system. The cluster messages are organized to be a cluster allocation table in memory, which enable the system to manage the recorder flexibly in high speed. Additional invalid blocks increasing in programming and erasing process will be labeled and bypassed by the hardware circuit.
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Computer Engineering. 2007, 33(12): 76-77,8. https://doi.org/10.3969/j.issn.1000-3428.2007.12.027MC is a manufacturing mode, which can solve the conflict between customer demands and manufacturing cost. When single enterprise can’t implement the mode, other SDN node enterprises do it by software platform. But the software platform demands data system more than common software. Thinking about the four types of MC, e.g. manufacturing for stock, manufacturing for manufacturing, manufacturing for assembly, and manufacturing for design, it analyzes the system demands of the MC software, namely, function demands, data demands, user interface, flow diagraph, and explanation, etc. Concept of SDN during the MC is shown.
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Computer Engineering. 2007, 33(12): 78-81. https://doi.org/10.3969/j.issn.1000-3428.2007.12.028Requirement analysis risk is an important content in project management. This paper builds a new software project requirement analysis risk evaluation model based on thirteen kinds of risks index. The model considers the risks of every project in the past as a 1×13 dimension row vector and them as the training vectors of SVM, then is divided into three levels: low risk, middle risk and high risk, the paper explains the application in software project requirement analysis risk prediction.
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Computer Engineering. 2007, 33(12): 82-83,8. https://doi.org/10.3969/j.issn.1000-3428.2007.12.029Against the limitations of the current software fault location, a new method based on checking codes is presented. The embedded modules are utilized to generate the implement sequence of software modules, and obtain a set of suspicious modules and their fault coefficients. Then, the codes of suspicious modules are checked by classification. Based on previous results, the set of suspicious codes and their fault coefficients are determined by the synthetical algorithm. The fault codes are located by eliminating the suspicious codes with the assistant tool. The method has been applied to the fault diagnosis of SIS, and proved to be effective for software fault location.
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Computer Engineering. 2007, 33(12): 84-86. https://doi.org/10.3969/j.issn.1000-3428.2007.12.030Checkpointing and rollback recovery is an effect way to improve system reliability and implement fault-tolerant computation. It is usually evaluated by overhead ratio, which is primarily effected by checkpoint overhead. As there is much communication blocking time while parallel program is running, a method based on copy-on-write checkpoint buffering is proposed to further reduce checkpoint overhead. By controlling the running of checkpointing thread and selecting a suitable granularity, the method can hide the overhead caused by checkpointing thread very well and thus reduce overhead ratio.
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Computer Engineering. 2007, 33(12): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2007.12.031Aiming at deficiency of building conceptual model of spatial database with E-R model, the ontological ideology and methodology are introduced into the geographic information domain. The exact meaning and its formal represented language of geographic ontology are discussed. Characteristics of spatial E-R model are clarified and relationship between geographic ontology and spatial E-R model is analyzed. The thinking of designing spatial E-R model based on geographic ontology as semantic foundation is presented. And a method of establishing conceptual model of spatial database by designing spatial E-R model from geographic ontology is introduced with an example about irrigation ontology represented by expanded OWL.
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Computer Engineering. 2007, 33(12): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2007.12.032Materialized views can improve the database’s performance, but numbers of materialized views will cost lots of spaces. So, it is necessary to decrease the number of the materialized views by merging. This paper gives a new algorithm named match merging. In order to accelerate the merging process, it introduces the two-partitioned tree, which is a kind of index. According to experiment, it is very useful.
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Computer Engineering. 2007, 33(12): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2007.12.033A data transformation of ontology based scheme for schema association resolution in finance domain is proposed to automate the process. Ontology annotation is used to express the relation between XML schema and ontology, ontology reasoning and schema match are used to express the match relation between schema element and path. In this way, XQeury script is built and data transformation is solved.
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Computer Engineering. 2007, 33(12): 96-98. https://doi.org/10.3969/j.issn.1000-3428.2007.12.034Using the specialty of the unsupervised clustering and the naïve Bayes classification, the paper gives a method that gains results of the text clusters and takes some of results as the training samples of the naïve Bayes classifier and let the trained naïve Bayes classifier reclassify those texts in illegible area of the clustering results. Consequently the method can classify the unlabeled text accurately and also can gain a better result of classification.
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Computer Engineering. 2007, 33(12): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2007.12.035A novel method called data-access-flow based index optimization (DAFIO) is proposed to provide automatic index select for database in order to improve the data access performance. By integrating the data model and process model of the IT systems and getting data access flow, the DAFIO method can analyze the data access flow to find those data item which are accessed frequently, and then create indexes for these frequent items. The experiment results show that the novel method is effective to improve the data access performance.
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Computer Engineering. 2007, 33(12): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2007.12.036Multivariate time series (MTS) subsequences, which differ significantly from the remaining MTS subsequences, are referred to as outlier subsequences. Tthe mining method for MTS outlier subsequences based on sliding window is proposed. An extended Frobenius norm is used to compare the similarity between MTS subsequences, K-NN searches are performed by using two-phase sequential scan, and MTS subsequences which are not possible outlier candidates are pruned which reduce the number of computations and comparisons. The MTS datasets of stock market is used for outlier mining, the results show the effectiveness of the algorithm.
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Computer Engineering. 2007, 33(12): 105-107,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.037To satisfy diverse application requirements and optimize network resource utilization, quality of service(QoS) routing needs accurate network state to compute path. However, the existing distance vector algorithms are difficult to accurately describe statistical characteristics of network state in time because of the limitations of network overhead and traffic characteristics, etc. State uncertainty becomes one of the key problems of QoS research. This paper proposes a distance vector(DV) routing algorithm based on state stability (SSB-DV), which improves periodic update mechanism of traditional DV algorithm. Computer simulation and analysis indicate that, on the basis of guaranteeing important routing performances like efficient throughput ratio etc, SSB
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Computer Engineering. 2007, 33(12): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2007.12.038To date, most of the grid resource monitoring systems adopt fixed period polling, but with less consideration about dynamic period. The paper presents a self-adaptation polling method, adopts unitary linearity regression, and solves some shortcomings of fixed period polling, experiment proves it is accurate.
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Computer Engineering. 2007, 33(12): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2007.12.039As more and more value-added data services are devoloped which require complex quality of service(QoS), this paper defines a wireless access network model with shared buffer and derives mathematical expressions for some QoS parameters. It proposes a joint CAC algorithm considering both packet-level QoS and connection-level QoS. The numerical results proves correctness of the method.
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Computer Engineering. 2007, 33(12): 114-116,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.040Network traffic is composed of many connections between hosts, which send all kinds of traffic data. Most studies focus on the statistic of integrated traffic, ignoring the microscopic relationship of different network flows. The paper focuses on analyzing the integrated traffic in a microscopic view, trying to find the relationship of network flows which are based on source and destination IP addresses and studying the difference of normal network flows and attack network flows in correlation.
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Computer Engineering. 2007, 33(12): 117-118,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.042Source Routing is a routing type which depends on the information carried by packet. In the experience of e-science, congestion and idlesse can be found in today’s network at the same time, so the management of source routing is important for mass data transmission. With the management of source routing, a more efficient schedule of network resources can be devised. SRM is designed, and many versions are supported to suit with various OS. A demo designed for fedora acheives experiment expectation and is ready for deployment.
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Computer Engineering. 2007, 33(12): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2007.12.041The paper proposes a multipath routing protocol(multipath routing protocol based on a hybrid criterion to choose routing, HC-MRP) based on DSDV in Ad Hoc networks. By the cross-layer technique, it proposes a hybrid criterion based on the shortest path criterion and the best channel state criterion, and establishes a neighbor node structure by which the multi-path mode can be expanded. The multi-path dividual transmission is employed as the transmission mode of paths. The simulation shows that by the mode of multi-path dividual transmission, the proposed protocol improves the throughput with a little price of the performance of delivery.
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Computer Engineering. 2007, 33(12): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2007.12.043This paper discusses a digital rights management(DRM) system applicable to P2P network, and advances its systematic architecture and basic protocol. The P2P-based DRM architecture includes topological structure, functional assignment and working flow, and focuses on the content management, content identification, royalty payment and quality control technologies. It puts forward its digital content uploading and downloading protocols, achieving an effective integration of P2P model and the DRM technologies.
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Computer Engineering. 2007, 33(12): 125-127,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.044This paper presents a way to estimate the saturation throughput of IEEE 802.11 for a lossy channel. The analysis which is involved in capture effects and backoff freezing procedures, is based on elementary conditional probability arguments. It uses this way to analyze the performance of the basic access and RTS/CTS access mechanisms of IEEE 802.11b. Simulation results show the analysis accurately predicts the saturation throughput in DCF mode.
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Computer Engineering. 2007, 33(12): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2007.12.045A fundamental factor of multicast deployment in wide area network is inter-domain multicast. A simple, useful inter-domain multicast architecture is constructed. It is named Any-to-Any (A2A) multicast, which means that it applies to any source multicast. Using Chord and PIM-SM as the basic protocols, A2A multicast has many good features such as well scalability, failover, and load-balancing. While supporting ASM very well, it is helpful for host mobile multicast. The architecture is described, and features and security issues pertaining to it are discussed.
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Computer Engineering. 2007, 33(12): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2007.12.046
To avoid the shortcomings in security, reliability and negative influence on original network performance, this paper brings forward a dynamic reconfiguration method based on information stream. Network dynamic reconfiguration implemented by this method can guarantee the important information can arrive at destination, and this method makes the information stream go through different ways, ensuring the whole performance of network to a considerable extent.
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Computer Engineering. 2007, 33(12): 134-136,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.047To solve the problem the known high quality key generate scheme is slow and inefficient, this paper builds an embedded truly random key generating system on the PDA devices based on a new method which is called as Xiao’s random key generating scheme. It analyzes the performance, efficiency, security about the proposed schemes and tests the generated sequence according to the standard of FIPS 140-2. The new system can get a batch of high-quality key meeting the requirements for information security system. It is quick, secure and efficient.
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Computer Engineering. 2007, 33(12): 137-138,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.048This paper proposes a new remote management method of IDS. Using it, the remote management port of the IDS has no IP address and TCP/IP suite, and transmitted data one way. It solves the secure problems of the present method effectively. The test result proves that the method is feasible.
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Computer Engineering. 2007, 33(12): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2007.12.049A geometric distortion correction algorithm for watermark image is proposed. In order to correct geometric distortions, the algorithm estimates the parameter of translation, rotation and scaling transform with Cartesian moment of the original image and the geometric distorted image. The algorithm can correct combine distortion as well as rotation distortion, scale distortion and translation distortion. Experiments demonstrate that the scheme is of sound correctional precision, stable performance, low complexity and can efficiently correct geometric distortions of high intensity.
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Computer Engineering. 2007, 33(12): 142-143,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.050This paper presents a proxy-based scheme to enhance the security of browsers and the whole security connection, which also supports multi-user. It describes the overall architecture of the scheme with emphases on discussion of communication module, certificate management module and cryptographic service module and some issues about their design and implementation. It also gives the extension and improvements of the scheme.
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Computer Engineering. 2007, 33(12): 144-147. https://doi.org/10.3969/j.issn.1000-3428.2007.12.051Taking subjective trust as the background in the open network, this paper proposes a trust valuation model, provides a concrete and reasonable formula of direct trust and recommendation trust valuation and other solutions, which solves the valuation of trusts among various entities. Through the research and analysis of simulate experiment, the feasibility and the rationality of this trust valuation model is further confirmed.
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Computer Engineering. 2007, 33(12): 148-150,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.052This paper designs and implements a blind detecting system for images steganalysis. The aim of devising the blind detecting systems is to discover images in networks with more veracity at condition of no original images. The wavelet decomposition is implemented in each color channel, the magnitude of decomposition coefficients and the log error between the actual coefficient and the predicted coefficient magnitudes are used to yield statistics. The non-linear support vector machine algorithm has been employed in the pattern discrimination. Its structure, principle, controlling process as well as the key designing technique of software are also presented in detail. It points out improvement direction.
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Computer Engineering. 2007, 33(12): 151-153. https://doi.org/10.3969/j.issn.1000-3428.2007.12.053Combing the development trends of network security problem and its relevant protection technologies. And by analying the means of the hacker attack and the precautionary measures development and changing, together with practical experience and research results, the paper designs and constructs a workable integrated network security protection system. In the system, four centres are used to implement the comprehensive protection function, which are named security protection, early warning and detection, emergency response and disaster backup and recovery centre. Application has shown that the system can improve the network security integration protection functions.
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Computer Engineering. 2007, 33(12): 154-156. https://doi.org/10.3969/j.issn.1000-3428.2007.12.054Based on the analysis of the obfuscating transformation technology used by malicious code, this paper formally specifies the obfuscating transformation, presents a framework of obfuscating transformation engine, and develops a prototype. The experiment results show that obfuscating transformation can be used to improve the survivability of the malicious code.
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Computer Engineering. 2007, 33(12): 157-159,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.055A precise definition of limited multi-verifier signature is presented and a new limited multi-verifier signatures scheme is proposed. In this new scheme, limiting multiple verifiers to verify the signatures is allowed by only one signature computation. The limitation of only one limited verifier in generic limited verifier signatures schemes is offset. The desired security notions are achieved based on the assumption that BDHP is intractable and the new scheme not only supports denial protocol but also has higher efficiency than performing generic limited single verifier signatures with multiple times.
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Computer Engineering. 2007, 33(12): 160-162,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.056Network security is based on secure protocols. Secure protocols in existence have offered a favorable protection for servers and network, but there’s no protection for endpoint. A TNC (trusted network connection) based authenticated protocol, which focus on endpoint integrity, is proposed. The secure protocol, which integrates endpoint integrity measurement and PKI (public key infrastructure) under trusted computing environment, can assure the trustworthiness of endpoint.
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Computer Engineering. 2007, 33(12): 163-165. https://doi.org/10.3969/j.issn.1000-3428.2007.12.057The methods used in SPAM detection which are adopted in SPIT detection so far have too many limits. This paper presents a new method of SPIT detection and prevention in NGN. This method is based on the detection of signaling and black lists in IP multimedia subsystem. And the broken of signaling is used to detect and prevent SPIT.
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Computer Engineering. 2007, 33(12): 166-168,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.058A dynamic Webpage protection system based on MySQL is designed and implemented. Both the Webpage files and the databases can be monitored and protected effectively, and the mechanism of different-machine backup makes sure that they can be restored in real time once they are juggled illegally. So the system can be applied to ensure the security of dynamic websites.
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Computer Engineering. 2007, 33(12): 169-171. https://doi.org/10.3969/j.issn.1000-3428.2007.12.059This paper discusses certificate revocation list (CRL). A CRL based on schedule storage is not perfect and it proposes a new CRL based on binary sorted tree. Compared to other methods, the new method can reduce the average search length that the certificate user looks for the revocative certificate compared with traditional CRL. It is capable of avoiding the disadvantage of the improved CRL that any update will cause the move of the records, and it optimizes the performance of the certificate revocation system. The scheme is easy to be realized.
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Computer Engineering. 2007, 33(12): 172-174. https://doi.org/10.3969/j.issn.1000-3428.2007.12.060The picture scrambling algorithms based on chaos are frequently used for images secure communications. This computing method harnesses the randomicity and the sensitivity of the original value of the Logistic chaotic sequence, to generate the real value sequence. This paper presents an image encryption technology based on chaotic sequences and fractional Fourier transform. The experimental results show that the technology is valid and has good security.
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Computer Engineering. 2007, 33(12): 175-177. https://doi.org/10.3969/j.issn.1000-3428.2007.12.061In a (t, n) threshold proxy signature scheme, which is a variant of the proxy signature scheme, the proxy signature key is shared among n proxy signers delegated by the original signer. Any t or more proxy signers can cooperatively sign messages on behalf of the original signer. Hsu, etc. propose a nonrepudiable threshold proxy signature scheme with known signers (HWW scheme), overcoming the disadvantages of the scheme proposed by Sun. Tan, etc. carry out the secure analysis on the HWW scheme and point out that it cannot resist the original signer and the system authority’s conspiracy attack. This paper points out that the original signer and proxy signer conspiracy may forge a legal proxy signature in the HWW scheme and gives an improved scheme.
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Computer Engineering. 2007, 33(12): 178-179. https://doi.org/10.3969/j.issn.1000-3428.2007.12.062Through the cryptanalysis of a new proxy digital signature scheme—anonymous proxy signature digital scheme proposed recently, it is found that this scheme has security leaks and the original signer can not only forge the proxy signer’s valid proxy signature, but also frame anyone else as his designated proxy signer. An improvement is given, and the security analysis shows that it can resist the forgery attacks and retains some merits of the original scheme.
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Computer Engineering. 2007, 33(12): 180-182. https://doi.org/10.3969/j.issn.1000-3428.2007.12.063All the two-key-lock-pair access control schemes are threatened by overflow problem. Besides that, under old scheme, user can own several kinds of right on one file only based on the supposition that the access right is increased by degrees.T o overcome the shortcoming of key-lock-pair access control scheme at present, a new two-key-lock-pair access control scheme is proposed, based on the property that integer can be denoted into only one binary digital. With perfect dynamic feature, the new scheme is simply realized. When a user (file) is deleted by system, it is no need to keep any information about the user (file). Thus, the efficiency of space usage is increased. Under new access control scheme, user can own several kinds of access right upon one file, and the possibility of overflow problem is significantly reduced with the new method.
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Computer Engineering. 2007, 33(12): 183-184. https://doi.org/10.3969/j.issn.1000-3428.2007.12.064A method about how to protect software is designed, which is based on dynamic register code. In the method, computer fingerprint is drawn and additional information is added, and the two are combined to be as characteristic information. Then MD5 algorithm is used to encrypt. The procedure is realized with VC++. Security is considered fully and some methods are adopted to enhance security.
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Computer Engineering. 2007, 33(12): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2007.12.065IPSec policy configuration remains a complex and error-prone task. A generic model that captures various filtering policy semantics using Boolean expressions is presented. This model is used to derive a canonical representation for IPSec policies using ordered binary decision diagrams. Based on this representation, a comprehensive framework is developed to classify and identify conflicts that could exist in a single IPSec device (intra-policy conflicts) in enterprise networks. The testing and evaluation study on different network environments demonstrates the effectiveness and efficiency of the approach.
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Computer Engineering. 2007, 33(12): 188-190,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.066In the system of privilege management infrastructure (PMI), the maintenance of attribute certificate is very important. Especially in the application environment where users’ roles are relatively fixed, unreasonable certificate revocation management will bring enormous operations or burden onto network transmission. And the release of certificate revocation list is founded by attribute authority (AA) and handed to a public directory to release. Because public directory cannot be ensured safe or credible, it cannot be supposed that the institution is credible in the release of revocation list. So the sign of AA is needed to ensure the authenticity of certificate revocation list. This paper puts forward a maintenance scheme of certificate revocation list, which solves the above problems. The validity, security and capability of this scheme are analyzed.
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Computer Engineering. 2007, 33(12): 191-192,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.067This paper presents an improved method for timing attack. It can attack the fast implementation of RSA, including Montgomery ex¬ponentiation algorithm and Chinese re¬mainder theorem. It gets the relationship between the input parameters and execution time of RSA by analyzing the probability of extra reduction during Montgomery ex¬ponentiation operation, and gets the secret factors bit by bit by timing analyzing with the chosen input ciphertexts, and exposes the factorization of RSA.
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Computer Engineering. 2007, 33(12): 193-195,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.068This paper analyzes the security protocol of IEEE 802.1X framework and its working principle. It gives a designing scheme of incorporating 802.1X into the authentication model of the Intranet security management system. This design scheme can support the usage of client model of 802.1X of a third party and RADIUS servers that are compatible to standard RADIUS protocol.
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Computer Engineering. 2007, 33(12): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2007.12.069A method of face detection is proposed, which is based on the color of skin. A skin color model is constructed, which detects skin area in a color image and figures out map of Mahalanobis distance to skin. Based on map of Mahalanobis distance eigenface subspace is found out and a BP neural network model is constructed. On the BP neural network, input is coefficient vector obtained from map of Mahalanobis distance projecting on subspace, and output determines whether this area is face image. Experimental results show the method is effective．
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Computer Engineering. 2007, 33(12): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2007.12.070This paper focuses on the engineering design knowledge representation on semantic Web, a global knowledge database. It models those categories of knowledge in the unique way. Using the RDF(S) technology, the ontology for engineering design knowledge on semantic Web is built. It brings out a store model for knowledge on semantic Web and its API, which paves the way for developing engineering design knowledge management system on semantic Web.
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Computer Engineering. 2007, 33(12): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2007.12.071This paper presents a new method for eliminating shadowed digital image combining high-dimension geometry calculation . In order to calculate a new image based on original one, it gets the new image through the way of convolution original image with a set of smoothing filter kernels, and then calculates the distance in Euclidean space and gets the last image point. Experimental results have shown there are better effects for shadowed image even for different category pictures.
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Computer Engineering. 2007, 33(12): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2007.12.072Planning and self-organizing are two common approaches for multi-robot collaboration. The former is highly precise but complicated to realize and is poor in robustness. The latter is adaptive to environment, but its process is with a little blindness because individual robot makes decision independently. To reduce the blindness in self-organizing approach, this paper proposes a self-organizing model based on double token for multi-robot coordination. In this model, a robot strategy adjusting mechanism is designed, which uses a two-level standard to evaluate robot’s strategy, and moreover a method of double token is used to coordinate the strategy adapting behaviors of robots. Simulation result demonstrates the effectiveness of this model by constructing a multi-robot control system based on the model.
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Computer Engineering. 2007, 33(12): 208-210,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.073Module identification is one of the key technique for product modularization design. While non-numerical value module identification method is more common, the method of numerical value mainly uses simulated annealing algorithms or genetic algorithms. Using simulated annealing algorithms can get the best solution of module identification at one time, but it is hard to operate and has low efficiency, using genetic algorithms easy gets into local optimization. This paper puts forward module identification way which is based on improved simulate annealing algorithms and researches the key techniques, blends the genetic algorithms’ population idea. This method is realized with Visual C++ 6.0. Using one example, this method is validated easy operation and high efficiency.
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Computer Engineering. 2007, 33(12): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2007.12.074Ontologies usually collaborate with each other. The standard OWL, only remains the owl:import interface, where anything can be imported completely. A clustering integrated collaboration is proposed for ontologies. It differs from current OWL which is extended (EOWL) by adding some new collaborative interfaces instead of using owl:import and so on. A clustered and layered collaborative management system is proposed for context track and reasoning for OWL-DL. It expands the OWL to EOWL and presents a solution of collaboration between ontologies and foreign ontologies in view of ontological language itself.
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Computer Engineering. 2007, 33(12): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2007.12.075Collision detection is an important technique enhancing virtual environment’s reality and immersion. The former collision detection methods computation is complex and it will waste a lot of system computation resource when the scene is large. So it brings forward a kind of collision detection method based on Z_buffer depth value. Making use of the information of transform matrix and Z_buffer depth when the scene is rendered, the method detects and responses quickly when user rambles in scene. Experiment data and testifies the method is simple, quick, and independent of the complexity of scene.
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Computer Engineering. 2007, 33(12): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2007.12.076For solving the traffic problems of P2P community streaming media communication, an overlay multicast model is suggested and some QoS parameters are restricted in its overlay core multicast tree(OCMT). A genetic algorithm(GA)using destination-oriented representation is proposed to optimize the OCMT tree. Simulation experimental results show that the model can obtain a rather optimal solution for building the multicasting tree with features of low delay and high scalability, which can reduce the traffic of P2P communities, and control the whole traffic of Internet.
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Computer Engineering. 2007, 33(12): 220-221,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.077This paper addresses the problem of detecting objectionable videos. An optical flow based key-frame selection algorithm is presented. It makes use of the key-frame and frames near it to select the foreground. With the view of bad illumination, a new gamma correction method before the skin detection is introduced. An effective determining rule is given. The experimental results show that the method’s correct detection is up to 80% and it is fit for the video detection environment.
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Computer Engineering. 2007, 33(12): 222-224,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.078The traditional way to search animation material is usually based on index, which may be time-consuming and can not achieve the satisfying outcome, for there are numerous materials in database. Using the methods supplied by the MPEG-7 standard, the interface of describing multimedia content, to search animation materials, reduces the manufacture cycle greatly and enhances the working efficiency.
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Computer Engineering. 2007, 33(12): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2007.12.079This paper presents a new method on 3D earth modeling based on the blue marble texture and GTOPO30 DEM data. The gaps between surface tiles are eliminated and the surface of the earth is simulated accurately. By means of multi-LOD of the texture and the DEM data, the 3D earth can be viewed from any direction and can also be zoomed. Such 3D earth can be adopted in visualizations such as flight simulation, missile launch and satellite orbiting. The modeling method also presents a new idea on other similar modelings, and is of high generality and usability.
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Computer Engineering. 2007, 33(12): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2007.12.080A novel algorithm based on fractal interpolation is presented for reconstructing 3-D surfaces. Unlike the existing general algorithms, which are appropriate only for dataset sampled on rectangular grids, the algorithm can deal with the initial points defined on irregular quadrangular grids. The experimental result shows its effectiveness and practicability for 3-D reconstruction.
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Computer Engineering. 2007, 33(12): 231-233,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.081In the embedded environment, demand of memory system is gradually increasing. More and more embedded systems adopt a high speed memory system to support the systems’ running and store a large number of data. As the speed and the volume of a memory system are extending, how to design a high speed memory system has become a problem which should be researched on. This paper uses a large amount of the DDR memory system design as an example to focus on the signal integrity problem. Using signal integrity simulation method, this paper analyzes and discusses how the proper signal termination modes and signal routing rules affect signal integrity. The method can be efficiently used in many different volumes of high speed memory system design, also in the latest DDR2 memory system design. With the method, implementation of the memory system gains a good result.
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Computer Engineering. 2007, 33(12): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2007.12.082The weapon system has too many fault diagnosis systems and is invested too much in re-development. To solve those problems, the design of the platform is analyzed. The hardware of it consists of a control computer with PC104 structure and multi-type signal test interface boxes of equipments. The software of it synthesizes the methods of expert system, neural networks and signal process. The system model of the weapon system is abstracted. The particularity that there is no diagnosis interface and can not plug in or pull out the connectors frequently is proposed. A principle that it is better to diagnose without the direct connect and the order of fault diagnosis is from electrical control system to hydraulic system is summarized. The platform is used in practical equipment and a better effect is achieved.
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Computer Engineering. 2007, 33(12): 237-240,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.083On the basis of the multi-section structure of the monitoring-control system for large-scale underground buildings, one multi-agent based control model for the buildings are brought forward. The model consists of operation and management Agent, middle-interface Agent, domain-monitoring-control agent and work-flow-monitoring-control agent. The behavior models of the two important agents, operation and management agent and domain-monitoring-control agent are probed and described in depth with UML, and the detailed implementations of the two agents are discussed.
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Computer Engineering. 2007, 33(12): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2007.12.084Embedded systems are often severely energy-constrained. The need to meet real-time requirements while staying within energy constraint presents new design challenges. Dynamic voltage scaling (DVS) is an effective technique for reducing processor energy consumption. The technique uses a hardware profiling scheme to identify “hotspot”, adjusts processor voltage and speed in response to the amount of ILP observed. In comparison to a processor running at a fixed voltage and speed, the approach can improve energy consumption with less impact on the performance.
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Computer Engineering. 2007, 33(12): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2007.12.085An integrated scheme of distributed digital supervision and large screen display is presented to avoid information island in the production process of manufacturing industry. The on-the-spot data is collected with serial real-time communication, processed by accessing the database and output in the large screen. An integrated system is developed to provide the platform for the decision in the production. The application in the manufacturing process of a compressor enterprise is given to demonstrate the proposed scheme and system.
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Computer Engineering. 2007, 33(12): 247-250. https://doi.org/10.3969/j.issn.1000-3428.2007.12.086The blood pressure and the pulse are two of important physiology parameters of human body, accurate measurement of the blood pressure and the pulse are playing vital role to the human body health. The principle of this instrument is pulse wave characteristic of time. It chooses the special pressure sensor BP300 which converts precisely the pressure signal to voltage signal and makes signal processing by the 8-bit SCM——ATMEGA16. The LED displays circulatory the results——systolic pressure, diastolic pressure and pulse. The instrument can be used conveniently and the results are presented obviously.
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Computer Engineering. 2007, 33(12): 251-252,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.087Programmable application-specific processor is necessary in order to increase communication system security and reduce manufacture cost. An application special processor is introduced for high quality multi-rate speech compression algorithm based on SELP(sinusoidal excitation linear prediction) model. The chip uses reconfigurable architecture and VLIW(very long instruction word) system design method, by which high complexity sub programs are optimized to get a remarkable instructions parallel. The simulation result shows speech compression algorithms which are implemented on this chip have higher efficiency than that on universal DSP(digital signal processor) under the same technical level, while maintaining the original coding quality. The chip can implement different types of speech compression algorithms and reach to good security, low complexity and development convenience.
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Computer Engineering. 2007, 33(12): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2007.12.088This paper researches and discusses the home network and residential gateway, and analyzes the requirement from operator A multi-access residential gateway, Intel network processor IXP425 based system, is designed for telecom operator to spread. Complete solution and hardware/software architecture of system are described and the key module design is presented.
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Computer Engineering. 2007, 33(12): 256-258,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.089At present, voice value-added services (VVAS) are growing sharply, but lack specifications. This paper proposes an architecture for voice value-added service platform (VVSP) based on the VoiceXML, which specifies the development and management interface of VVAS, discusses the function and framework of voice value-added service execution platform (VSEP) and voice value-added service management platform (VSMP), and illustrates several key flows used to implement the services on the architecture. VVSP is compared with current interactive voice response (IVR) platform.
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Computer Engineering. 2007, 33(12): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2007.12.090This paper presents the design and implementation of a retargetable cycle-accurate simulator for transport triggered architecture (TTA). Different TTA hardware architecture can be simulated without modification of the simulator itself. Flexible interface to add user-custom instructions is also provided. To increase the simulation speed, a pre-interpretation mechanism is presented.
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Computer Engineering. 2007, 33(12): 262-263,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.091Mobile Ad Hoc networks (MANET) are highly dependant on the different types of nodes and the physical network environment. During the research on MANET, simulation can reflect only a partial behavior for the new protocols in the reallife. Deploying real-life MANET is therefore an indispensable complementary step for the advancement of MANET. This paper presents a Java-based secure MANET application framework——J-SMAF, which brings the intrusion detection system into the flexible and extensible application framework. With J-SMAF, people could build healthy and secure MANET real-life evaluation test-bed and application system easily on different platforms and in various environments.
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Computer Engineering. 2007, 33(12): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2007.12.092In order to solve the problems concerning the development of E-government system, a schema based on unified network infrastructure and unified information security system is put forward. In this schema, E-government systems of all departments are connected by unified E-government platform. Data and services to be shared are switched from non-standard style to standard style and published. Users can get shared data and services by invoking interfaces published before. After explaining the architecture of provincial E-government system, this paper elaborates on the multilayer logical model, the solution of information share and exchange, the publishing and using procedure of shared data and the using procedure of sharing data.
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Computer Engineering. 2007, 33(12): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2007.12.093The computer selection of charge checking case uses computer as a tool, according to scientific case selecting indexes, to find out exceptional charging units by processing, analyzing and filtrating internal and external data. This paper presents a model of charge checking case selection based on decision-tree: proposes the organization method of metadata for charge checking case selection, describes how to extract charge checking case selecting subjects and constructs its multidimensional model and uses decision-tree method in charge checking case selection. Based on the case selecting model, the computer selection system of charge checking case is implemented, which improves the efficiency, veracity and scientificity of charge checking.
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Computer Engineering. 2007, 33(12): 270-271,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.094As FPGA is reconfigurable in logic and can be readback in data, this paper designs a reconfigurable system based on Xilinx VirtexTM FPGA. CPU and CPLD are used to configure FPGA which selects a SelectMAP configuration mode and readback configuration data in it. The paper introduces the process of the system to implement the configuration and readback function. Part of the results are shown in wave charts.
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Computer Engineering. 2007, 33(12): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2007.12.095
Traditional GIS-based oil spill information system can be used only on networked PCs which are physically tied to locations with limited accesses and restricted to certain platforms of operating systems. In order to provide a more convenient, accessible GIS application and response information to support timely decision in oil spill emergency response, the paper proposed the construction of marine oil spill response information system based on WebGIS. Based on the system structure and functions, the authors developed the oil spill behavior simulation module using numerical modeling technique, established the response information databases, developed the system server and client application programs by using GIS, dynamic Web, database techniques, and also discussed the system integration and visual display of numerical simulation result on WebGIS. Preliminary results showed that such an integrated approach of combining WebGIS, database and numerical modeling provided effective solutions as needed in an oil spill contingency.
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Computer Engineering. 2007, 33(12): 275-276,. https://doi.org/10.3969/j.issn.1000-3428.2007.12.096In traditional 8051 SCM system, due to the restriction of resource in SCM system, the software design about user interface is burdensome, and not easy to transplant. Aiming to these shortcomings, on the base of introduction of uC/GUI’s(embedded graphical user interface) characteristics and requests of transplantation, feasibility of transplantation of uC/GUI in SCM system is analyzed. With the example of C8051F120 SCM system, the transplantation application process of uC/GUI in SCM system is described, and the experimental procedure is given.
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Computer Engineering. 2007, 33(12): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2007.12.097The embedded system Windows CE.net can be stored and be booted in many ways. It is introduced that an Eboot of embedded processor Intel PXA270 uses NAND flash to store and boot Windows CE.net system, and a boot technique is introduced that Windows CE.net 5.0 runs with the storage device of NAND Flash. The technique is universal, quick-boot and low-cost.
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Computer Engineering. 2007, 33(12): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2007.12.098Honeycomb-like rapid embedded system platform (HLRESP) is developed by Fudan university. This platform is in modularized structure, and it can configure module blocks freely. For the sake of the system test and debugging, the design of boundary-scan and the integrality test and interconnect test of boundary-scan is very important to the platform. A boundary-scan tester software is designed based on Eclipse for this system test and debugging. This software can build the test vectors automatically, analyze the response data and locate fault accurately.
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Computer Engineering. 2007, 33(12): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2007.12.099The paper proposes a new method based on B-spline network, modeling complex principal curve. This method combines the polygonal line algorithm of learning principal curve with B-spline network. The iterative algorithm for searching bifurcate point is proposed. Simulation results demonstrate that it is feasible and effective.
2024
Volume 50 No 3
Volume 50 No 3
(Started in 1975, Monthly)
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428