05 June 2011, Volume 37 Issue 11
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Computer Engineering. 2011, 37(11): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2011.11.001
The problem of ghost objects seriously affects the intelligent video surveillance application in background subtraction method for moving objects detection in videos. According to the characteristic that the ghost’s foreground and the true object’s foreground are different in the similarities of edge, and by defining edge similarity measure functions, this paper presents a ghost discriminant algorithm based on edge similarity. Experimental results show that compared with traditional methods, this method is effective and robust.
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Computer Engineering. 2011, 37(11): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2011.11.002
In order to study the interaction between user behavior and Peer to Peer(P2P) file sharing systems, this paper proposes a mathematical model. The contributions include: considering the guide strategy factor for the first time in P2P model based on user behaviors; analyzing the impacts of guide strategy on user behaviors and system performance; comparing the effects of three guide strategies. Simulation results show that guide strategy can effectively improve the probability of first downloading good file, and reduce the number of retrial and overall traffic.
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Computer Engineering. 2011, 37(11): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2011.11.003
Based on the research of SMBIOS entry point structure, SMBIOS structure tables and memory-mapped I/O, this paper puts forward a method of universal Basic Input/Output System(BIOS) image file sampling and formatting, and establishes a BIOS image file security detection model. Experiments prove this method can analyze multiple IBV’s(Independent BIOS Vendor) BIOS image files successfully, thus it solves a critical problem in BIOS security risk analysis and detection system.
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Computer Engineering. 2011, 37(11): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2011.11.004
According to the existing problems of dominate cells information missing, an automatic data mining method of contingence table is purposed. According to the location of dominate cells, the categories in the original table are classified and represented by tree structure models on the basis of relevant theories of Multinomial Processing Tree(MPT) models, the following processes including hypothesis generations, parameter estimation and goodness-of-fit test is performed automatically. Application result shows the approach can effectively extract the latent interactions and peculiarity association rules.
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Computer Engineering. 2011, 37(11): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2011.11.005
In order to improve water quality evaluation of multi-spectral image accurately, this paper puts forward a model for water quality evaluation of Radial Basis Function(RBF) neural network based on optimized parameters of Genetic Algorithm(GA). The method uses SPOT-5 data and the water quality field data. It chooses four representative water quality parameters. RBF neural network is trained and tested, and the parameters of RBF neural network are optimized by particle swarm optimization algorithms. Water quality parameters of COD, NH3-N, DO, CODmn are retrieved by the trained RBF neural network. Experimental result shows that the method has more accuracy than the routine method.
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Computer Engineering. 2011, 37(11): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2011.11.006Drivers decision to go or stop during the yellow interval belongs to uncertain decision making. This paper collects drivers behavior data at four similar intersections. Fuzzy Decision Tree(FDT) is applied to model driver behavior at signalized intersection. Considering vehicle location, velocity and countdown timer as the influencing factors, the FDT model is constructed using FID3 algorithm, and decision rules are generated as well. Test sample is applied to test FDT model, and results indicate that FDT model can predict drivers’ decision with overall accuracy of 84.8%.
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Computer Engineering. 2011, 37(11): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2011.11.007With the help of biological and economical research fruits, this paper analyses Peer’s behavior from evolutionary game theory so as to keep the P2P system dynamical balance. It describes the P2P network and quantifies Peer’s contribution. It proposes a probability model and introduced replicator’s dynamical equation. The incentive mechanism is set up by changing related parameters in random game payoff matrix. Simulation results indicate the model is practicable and flexible.
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Computer Engineering. 2011, 37(11): 22-24,27. https://doi.org/10.3969/j.issn.1000-3428.2011.11.008Frequent decoding operations severely reduce the optimization efficiency when the binary Quantum Genetic Algorithm(QGA) based on qubits measure is applied to the continuous space optimization. Aiming at the problem, an improved QGA based on phase of qubits encoding is proposed. The chromosomes are encoded by the phase of qubits, updated by quantum rotation gates, and mutated by quantum Pauli-Z gates. As the optimization process is performed in , the algorithm has good adaptability for a variety of optimization problems in the different scale space. Taking parameter optimization of Takagi-Sugeno(T-S) fuzzy controller of single level inverted pendulum as example, the simulation results show that the algorithm has advantages in search ability and optimize efficiency.
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Computer Engineering. 2011, 37(11): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2011.11.009This paper introduces a novel automatic text clustering method, in which the Genetic Algorithm(GA) is applied to the global optimal and high searching efficient feature selection to achieve dimensionality reduction, then appropriate number of partitions of document set are created according to the different combinations of feature weights, and each document partition is clustered into an initial clusters based on dynamic programming technique, and all initial clusters are clustered using the same method to final text clusters. Experimental results show the method can achieve dimensionality reduction efficiently, improve the text clustering precision, and decrease the clustering time.
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Computer Engineering. 2011, 37(11): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2011.11.010When Intersecting Cortical Model(ICM) processing the images, it generates errors for improper operation of connection matrix. A new set method for connection matrix is proposed. The edge detection algorithm based on ICM is introduced, which identifies the sparking scope of neuron. It is applied in edge extraction of fuzzy medical images. Experimental results show that, compared with other algorithms, it has higher accuracy and can extract fuzzy medical images edges better.
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Computer Engineering. 2011, 37(11): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2011.11.011Resource monitoring is an important part of resource management in the cloud computing environment, so as to provide reference for resource allocation, task scheduling and load balancing. The resources in the cloud computing environment are highly virtualization, scalability and transparency, in addition cloud computing target is commercial applications need for statistical resources using of users for billing, so the existed resource monitoring methods can not fully meet the cloud computing environment. According to the characteristics of cloud computing platforms, it presents a novel resource monitoring model while adapt to cloud computing environment, the model by Virtual Machine Monitor(VMM) and the Java call C/C++ to get information of the resource status. Through theoretical analysis and experiments show the model can be used to collect resource monitoring information on nodes, it meets the requirements of cloud computing platform features.
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Computer Engineering. 2011, 37(11): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2011.11.012This paper proposes a High Performance Computing Application Packaging method based on Template(HPC-APT), which is cross-platform, simple syntax, easy maintenance and extension, and user-friendly. HPC-APT supports Web and windows application in main grid middleware or cloud computing platform. HPC users can submit jobs to remote HPC clusters via Web or windows application interface, so that the entry barrier of HPC cluster is greatly reduced and the usability is highly increased.
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Computer Engineering. 2011, 37(11): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2011.11.013The mass data from Web are distributed, heterogeneous and dynamic, so the current data mining system based on single node has developed to a bottleneck. Using the advantage of cloud computing——distributed processing and virtualization, this paper presents a Weblog analysis platform under the Hadoop’s cluster framework based on cloud computing, it also presents a hybrid algorithm which can distributed process in the cloud computing environment. To further verify the effectiveness and efficiency of the platform, it uses the improved algorithm to mine users’ preferred access path in Weblog on the platform. Experimental results show that, using distributed algorithm to process large number of Weblog files in the cluster, can significantly improve the efficiency of Web data mining.
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Computer Engineering. 2011, 37(11): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2011.11.014
It exists problems of big size, high power and low efficiency when cloud computing center is composed of traditional sever. This paper designs and implements a new cloud computing server. It discusses the key technologies, such as cloud processors, 3D-torus net, hardware virtualization, etc. Compared with traditional servers, the new one has the characteristics of small size and low power.
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Computer Engineering. 2011, 37(11): 43-44,48. https://doi.org/10.3969/j.issn.1000-3428.2011.11.015Aiming at the optimization problem of the cloud computing’s service cluster resource schedule and loading balance, this paper presents cloud computing resource schedule strategy based on Modified Particle Swarm Optimization(MPSO) algorithm. In order to control the global search and local search effectively, and to avoid falling into local optimal, it introduces dynamic multi-group collaboration and the reverse of the flight of mutation particles to the Particle Swarm Optimization(PSO) algorithm. By extending the cloud computing emulator CloudSim platform to test the simulation, the results show that this method is effective, and the operation efficiency is high.
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Computer Engineering. 2011, 37(11): 45-48. https://doi.org/10.3969/j.issn.1000-3428.2011.11.016This paper introduces the resource allocation model which is based on the Continuous Double Auction(CDA) mechanism and the pricing strategy of the supplier and the demander under cloud computing environment. After the law of the failure of resources nodes is analyzed, it promotes a dynamic resource allocation strategy which is based on the CDA mechanism and the credibility of the nodes. Matlab simulation results show that the strategy can ensure the creditability of the resources, improve the operation efficiency and maximize the Quality of Service(QoS) when dynamically providing resources.
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Computer Engineering. 2011, 37(11): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2011.11.017On the basis of Google open cloud environment, through the analysis of network topology and location information based on the relationship between the server location in the cloud environment, this paper gets hierarchical network topology map of collection of data blocks in the cloud environment, and gets risk assessment model through the analysis of data block distribution to the storage resources in the cloud environment and gives specific examples of risk calculation algorithms and specific example analysis and provides a theoretical risk basis for cloud storage resources in the cloud environment.
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Computer Engineering. 2011, 37(11): 52-55. https://doi.org/10.3969/j.issn.1000-3428.2011.11.018
Efficient resource provision and schedule is the key to build a private cloud environment. This paper presents a resource provision and schedule approach based on the proposed cloud application meta-model for cloud applications in a private cloud environment. It creates a minimum spanning tree according to the characteristics among virtual machines, and splits the set of virtual machines and maps them to the physical hosts by using the graph theory based on split clustering algorithm. The experiments and comparative analysis of the method for virtual machines show that the approach is efficient in enhancing the overall performance of cloud applications while reducing the consumption of physical network equipments and bandwidth resources.
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Computer Engineering. 2011, 37(11): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2011.11.019In incomplete information system, objects of the tolerance class and maximal consistent block in the attribute reduction algorithm based on discernibility matrix are uncertain. Aiming at the problem, this paper presents a new definition discernibility matrix and its core. And it proves that the core of this discernibility matrix is equivalent to the core based on positive region in incomplete information system. An algorithm of compute core is provided. An example illustrates that the elements of discernibility matrix in this algorithm reduce and the efficiency of computing core is improved.
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Computer Engineering. 2011, 37(11): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2011.11.020This paper introduces the idea of T-testing into privacy preserving data mining algorithms, proposes privacy preserving association rule mining algorithm based on influence measure. Considering influence measure as association rules generated as a criterion is to reduce the redundant rules and irrelevant rules so as to improve the efficiency of mining. Sensitive rules can be hided by adjusting the transaction association rules between the sensitive rule hiding sensitive items to achieve. Experimental results shows that, the algorithm makes the rules for side effects such as loss rate and the rate of decrease to as low as 6%.
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Computer Engineering. 2011, 37(11): 62-63,66. https://doi.org/10.3969/j.issn.1000-3428.2011.11.021Based on Graph Decomposition Index(GDI) algorithm, by using relational model to store decomposition information of the graph and utilizing B* tree to index degree of node in graph, this paper proposes a new subgraph isomorphism algorithm named Relational Graph Decomposition Index(RGDI). Experimental results show that compared with GDI, RGDI can save more storage space, get more precise candidate sets and has higher detection efficiency.
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Computer Engineering. 2011, 37(11): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2011.11.022Aiming at the problem of service matching between logical and physical layers when transforming from logical models to physical ones, this paper proposes an approach of service matching between logical and physical layers on the basis of semantic similarity. It solves the problem of service matching between different layers in the automatically realization of data-centric process. It introduces three types of interfaces dependency so that to improve the accuracy and recall of matching. Experimental results validate the availability of the method.
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Computer Engineering. 2011, 37(11): 67-68,73. https://doi.org/10.3969/j.issn.1000-3428.2011.11.023It expands transform nuclear of one dimensional Discrete Cosine Transform(DCT) into the two dimensional fractional type, gets two dimensional discrete fractional cosine transform of Pei type. Then an improved type of two dimensional discrete fractional cosine transform is purposed which is a weighted combination of the integer-order cosine transforms of the original signal. It analyzes the period connection of the two types transformations based on feature value and feature vector of DCT. Numerical value simulation result indicates that the two types of transformation can get the same results, and it can be applied in image processing, digital watermark technology.
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Computer Engineering. 2011, 37(11): 69-73. https://doi.org/10.3969/j.issn.1000-3428.2011.11.024In order to address the semantics annotation problem in the context of the components composition, this paper proposes a method to implement the automatic annotation technology of components based on the process algebra. It can reduce the manual workload of annotating the composite components for component library developers. It adopts ontology to describe the semantics of each component and uses the evolution of process algebra to extract the execution sequence according to the behaviors in the structural component composition. After that, we discuss the methods about how to extract and synthesize the semantics, and give out the corresponding algorithms. Finally, this method has been implemented and integrated into JTangComponent, where the results of experiments show that the proposed approach provides better automation on annotating the semantics and guarantee for reusing the components in semantic level.
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Computer Engineering. 2011, 37(11): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2011.11.025To improve search efficiency and storage performance of multi-version in collaborative design, this paper presents a definition of incremental version based on analyzing the evolution of versions and relationship between the versions in structure of directed acyclic graph which some versions are saved as entirety and others saved as incremental. After using it, the related versions can be restored in two ways and the structure of multi-version Directed Acyclic Graph(DAG) is changed into the one undirected graph. The algorithm is designed to optimize the distribution of multi-version. In the algorithm, versions recovery cost is calculated from differences between adjacent versions, and the best distribution mode of versions is selected based on the minimum versions recovery cost calculated using the ideas of improved Floyd algorithm. Analysis and examples results demonstrate that this method increases the safety and reliability of version data and improves searching efficiency of all the versions, and the algorithm has higher calculating efficiency at the same time.
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Computer Engineering. 2011, 37(11): 77-79,82. https://doi.org/10.3969/j.issn.1000-3428.2011.11.026Aiming at the processors load imbalance problem in shared memory multiprocessor system, this paper provides a new task scheduling algorithm——Multiple Wave Front Method(MWFM). MWFM improves the original Wave Front Method(WFM) by the way of hierarchical scheduling based on dividing the task graphs. It traverses and reallocates task sequences to reduce the error, improves the accuracy of the results of task scheduling by cyclic scheduling algorithm, and gives the implementation of the parallel algorithm. Experimental results prove that the algorithm can significantly reduce errors and improve the efficiency of the parallel systems.
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Computer Engineering. 2011, 37(11): 80-82. https://doi.org/10.3969/j.issn.1000-3428.2011.11.027Refactoring is a key technique to acquire software quality. The traditional method of locating refactoring mostly relies on observations and subjective perceptions, which is inefficient. A method of locating refactoring based on slice metrics is proposed. It uses coarse-grained slice to measure the coupling of class and locate the classes which need refactoring. A case demonstrates that the method is efficient, and outperforms the conventional method.
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Computer Engineering. 2011, 37(11): 83-85,88. https://doi.org/10.3969/j.issn.1000-3428.2011.11.028Content-based Semantic Web retrieval only considers the content itself, without taking into account the different users, and it can not accurately reflect user needs. Aiming at the problem, this paper proposes a framework for adaptive semantic Web retrieval. For Chinese documents on the Web, it gives a kind of ontology learning method with HowNet, builds user information database by extracting the user objective, explicit and implicit information, designs the initial query ontology and personalized query ontology construction algorithm, and ultimately achieves the user’s adaptive retrieval. Result shows the method has higher retrieval efficiency.
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Computer Engineering. 2011, 37(11): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2011.11.029In order to improve text clustering performance, this paper proposes a text clustering method based on word hyperclique. It evaluates document similarity with word relationship between documents, works with word hyperclique as assistance of the document’s vector and uses a corresponding clustering algorithm by graph to partition the document sets. Experimental results validate the effectiveness of the algorithm for improving clustering performance.
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Computer Engineering. 2011, 37(11): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2011.11.030To the common of decision tree and data warehouse in the data mining field, this paper creatively combines both of them. In order to provide fully decision support, it includes combination of representation and operation based on Online Analytical Processing(OLAP). After adopting the combination, the problems such as high storage occupation, low query speed and high error probability of classified decision information which resulted from decision tree’s increasing are conquered. After applying this combination to some travel agency’s client information database, this project turns out a affirmative feasibility and superiority.
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Computer Engineering. 2011, 37(11): 92-93,99. https://doi.org/10.3969/j.issn.1000-3428.2011.11.031Clique Partition(CP) problem in graph theory is NP-complete, so it’s difficult to solve it in polynomial time. This paper studies fixed parameter algorithm for CP and proposes a new reduction rule for K4-free graphs. Combing with the way of depth-bound search tree, it improves the running time of Fixed Parameter Tractable(FPT) algorithm for Clique partition in K4-free graph. Experimental results show that the efficiency of the improved algorithm is higher than the original at least thirty percent in the case of sparse graph.
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Computer Engineering. 2011, 37(11): 94-96,102. https://doi.org/10.3969/j.issn.1000-3428.2011.11.032Most of the existing exception propagation analysis methods are limited in intra-class, which can not meet the requirement of software development. This paper presents an exception propagation analysis method of object oriented program, which builds an Object Oriented Exception Propagation Analysis Graph(OEPAG) based on the control flow graph of classes. After obtaining the path of exception propagation and the relation of classes, it is effective to analyze the control flow and data flow. Application result shows that result based on OEPAG is more accurate than traditional methods when computing slice for programs which includes exception handling structure.
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Computer Engineering. 2011, 37(11): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2011.11.033In the case of multi-sensors measurement of many times on some characteristic index, a new fusion method is proposed. A membership function in fuzzy set is used to measure the mutual support degree of observation values, and the integrated support degree of data from various sensors is measured through an augmented support degree matrix. According to this augmented matrix’s maximum modulus eigenvectors, corresponding weight coefficients of all the observation values are allocated, hence, the final expression of data fusion is obtained. An example and a simulation are used to compare the proposed method with another two similar fusion methods. Result shows that this method has both higher precision and strong ability of stableness.
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Computer Engineering. 2011, 37(11): 100-102. https://doi.org/10.3969/j.issn.1000-3428.2011.11.034In order to seek tradeoffs between spectral efficiency and data reliability, this paper presents an efficient and low-complexity transceiver scheme for the hybrid STBC-VBLAST(Vertical Bell Labs layered Space-Time) systems. The hybrid Multiple Input Multiple Output(MIMO) communication systems can achieve multiplexing gain and diversity gain. The symbols are transmitted as VBLAST coding systems by exploiting the linear dispersion codes. An Ordered, Successive Interference Cancellation(OSIC) decoding algorithm based on sorted QR decomposition is proposed. Simulation results show the scheme outperforms other hybrid schemes in Bit Error Rate(BER) and computing complexity.
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Computer Engineering. 2011, 37(11): 103-104,107. https://doi.org/10.3969/j.issn.1000-3428.2011.11.035For some current Quality of Service(QoS) routing protocols, after choosing the path from source node to destination node, the special QoS flow of satisfying demand will transport data packages with the path, until the path disconnection. This paper proposes a new bandwidth and energy constrained routing protocol named BERP(Bandwidth and Energy Route Protocol). BERP is based on classic AODV(Ad hoc On-demand Distant Vector) protocol. It modifies routing discovery and maintenance mechanism for the QoS routing protocols, which is based on AODV and featured by bandwidth. By this way, all the node energy consumptions in network become more balanced, and simulation result shows the life time of the network is prolonged.
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Computer Engineering. 2011, 37(11): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2011.11.036Current trust administration models based on global reputation by using flooding method have high time complexity and excessive incurred packets, thus limit the scalability when applied to Peer to Peer(P2P) networks. With comprehensive consideration of nodes and behavioral diversity in the P2P network model allows the introduction of incentive P2P network model of credit management more network adaptability. This paper analyzes the resources discrimination trust administration models scheme DiffTrust, and proposes while its foundation the adaptation node and many nodes carry on the resources transaction application environment the MultiTrust model. Experimental results show that MultiTrust model has better stage earnings and shorter credit recovery time.
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Computer Engineering. 2011, 37(11): 108-110,113. https://doi.org/10.3969/j.issn.1000-3428.2011.11.037This paper proposes a new congestion control algorithm for wireless sensor networks that it can assign a fair and effective transmission rate for each node. It designs the algorithm and describes the requirement of parameters(input and output speed, control efficiency, fairness, time interval, reverse data transmission) in algorithm. It also research the fluctuation of speed rate. Simulation results by using an event-driven packet level simulator show that the proposed algorithm can effectively improve the network throughput, ensure network fairness and reduce the energy consumption.
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Computer Engineering. 2011, 37(11): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2011.11.038An algorithm based on the power allocation and feedback filter is developed to reduce Inter-Carrier Interference(ICL) and Inter-Sign Interference(ISL) of Turbo-OFDM(Orthogonal Frequency Division Multiplexing) system. The algorithm closes the inefficacy sub-band by power optimization, and reduces the length of channel impulse response by chosen feedback filters. It can simple the equalization of Turbo codes and reduce the length of CP, simulation results show that the algorithm perfects the frequency efficiency and has better performance than Turbo-OFDM system.
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Computer Engineering. 2011, 37(11): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2011.11.039In the unstructured Peer-to-Peer(P2P) network, free-riding behavior and distributed file request cause node load degree balanced. This paper proposes a link migration and cache strategy to transfer extra load from heavy-load nodes to light-load nodes, also caches hot files to link nodes. Simulation shows that, when query requests in the network conforms to Zipf distribution, the link migration and cache strategy can make network nodes more balanced and also reduce whole system load.
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Computer Engineering. 2011, 37(11): 117-119,122. https://doi.org/10.3969/j.issn.1000-3428.2011.11.040In order to solve the problem of the establishment of network trust, this paper brings up a trusted network model based on Trusted Platform Module(TPM) security chip, which is based on the theory of trusted computing and trusted network access technology. This model describes the establishment of trusted chain and expands the trusted chain to the network, then gives the model structure and information flow analysis, and makes the trust of metric computation. Through performance analysis, results show that the network model has a strong robustness and high credibility.
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Computer Engineering. 2011, 37(11): 120-122. https://doi.org/10.3969/j.issn.1000-3428.2011.11.041In modeling satellite network, routing simulation is one of the key problems that must be resolved. On the basis of analyzing the features of satellite routing, a routing scheme based on plans is proposed. A model is accomplished based on the Internet Protocol(IP) process model of OPNET, and the procedure is discussed in detail. Simulation results show that the routing simulation scheme can support satellite network modeling effectively.
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Computer Engineering. 2011, 37(11): 123-125,128. https://doi.org/10.3969/j.issn.1000-3428.2011.11.042Dynamic Source Routing(DSR) protocol is not quick enough to adapt to fast-changing topology of Ad Hoc network. To solve the problem, this paper introduces a conception of adjacency information table, presents a new protocol of DSR based on Adjacency Information Table(AIT-DSR). The protocol accelerates the route discovering, shortens the route, repairs the invalid route and avoids the high-load node. The packet loss rate and the average end-to-end delay decrease. It is proved by the results of simulation experiment.
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Computer Engineering. 2011, 37(11): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2011.11.043There is no feasible method to rebuild routing and reestablish communication in disconnected networks due to malicious attacks. This paper proposes a hybrid routing schema based on Ad Hoc routing and delay tolerant routing. On demand Delay Tolerant Network(DTN) routing schema is used to guarantee routing process based on DTN routing’s delay tolerant ability after failure occurring in adhoc routing. By evaluating packet delivery rate and end-to-end latency, the experiment proved that the proposed routing schema is a feasible method which can rebuild routing and reestablish communication efficiently and rapidly in disconnected networks. Not only high delivery rate can be guaranteed but also latency can be shortened by using local AODV.
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Computer Engineering. 2011, 37(11): 129-131. https://doi.org/10.3969/j.issn.1000-3428.2011.11.044The channel capacity of orthogonal Space Time Block Coding(STBC) is investigated over Rayleigh fading channels. The capacity analysis and calculation are provided based on two different Channel State Information(CSI) cases, one is perfect CSI known at the receiver only, the other is perfect CSI available at the transmitter and the receiver. When the receiver knows the CSI only, an approximate expression of the channel capacity is derived by using Taylor series expansion. This expression can simplify the calculation of the existing exact expression effectively, and obtain similar results with the true value. When the transmitter and the receiver both know the CSI, a simple calculation method based on the steepest descent algorithm is proposed to obtain the optimal cutoff threshold. This method can avoid large number of search and calculation from the existing method. Simulation results show that the derived exact and approximate expressions of the channel capacity are good agreement with the corresponding simulated values, and thus the validity of the theoretical formulae is confirmed.
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Computer Engineering. 2011, 37(11): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2011.11.045A Successive Interference Cancellation(SIC) detection algorithm is proposed based on Minimum Mean Square Error(MMSE) under the condition that Direct Sequence spread spectrum Code Division Multiple Access(DS-CDMA) system with heavy Multiple Access Interference(MAI). The algorithm can effectively track the time-varying channel and avoid decision error diffusion. Simulation results show that the algorithm has a higher detection accuracy and error performance than SIC algorithm and Zero Fighting(ZF) for the weak signal power users in the DS-CDMA system with Additive White Gaussian Noise(AWGN).
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Computer Engineering. 2011, 37(11): 135-137. https://doi.org/10.3969/j.issn.1000-3428.2011.11.046Malicious hardware components can be covertly inserted at the design and foundry of Field Programmable Gate Array(FPGA) to implement hidden backdoors for unauthorized exposure of secret information. This paper proposes a new class of hardware Trojan which intentionally induces physical side-channels to convey secret information. Power side-channel engineered to leak information below the effective noise power level of the device is demonstrated. The Trojan side-channel is implemented and it is evaluated with respect to the feasibility on FPGA. Spread spectrum technology used for parallel leakage of multi-key shows this type of Trojan is very flexible in design.
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Computer Engineering. 2011, 37(11): 138-140,143. https://doi.org/10.3969/j.issn.1000-3428.2011.11.047Analyzing the characteristics and requirements of cryptographic algorithm evaluation, the component-based automation evaluation system for cryptographic algorithm is designed and implemented. Using the dynamic framework, evaluation components and cryptographic algorithm components, the system can achieve the flexibility of dynamic integration of different cryptographic algorithms and evaluation functions. According to the operation mode of the dynamic framework, the form of data interaction and call relationship among different parts are designed and proposed. Using XML language, the evaluation requirements and data are described, so as to achieve the automation evaluation of cryptographic algorithm.
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Computer Engineering. 2011, 37(11): 141-143. https://doi.org/10.3969/j.issn.1000-3428.2011.11.048This paper presents a dynamic network intrusion detection and risk prediction model based on artificial immune thought, gives network attack detection process, antibody concentration calculation method and risk prediction process of Auto-regressive sliding average model based on time squence. Experimental results show that the model can quantitative analyze the current network risk and predict the future risk, and it can detect network risk real-time and has good prediction results. Compared with GM(1, 1) model, it has more accurate results.
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Computer Engineering. 2011, 37(11): 144-145,163. https://doi.org/10.3969/j.issn.1000-3428.2011.11.049This paper proposes a binding term theory and constructs the proposition of the prerequisites of authentication protocols based on the binding term theory, which is proved by strand space theory. It takes three classical authentication protocols as examples to verify the proposition proposed. The proposition can decide not only the freshness and the validity of principals, but also the authentication protocols containing type attack flaw. And a simple and effective formal method is provided for deciding security properties of authentication protocols.
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Computer Engineering. 2011, 37(11): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2011.11.050Aiming at the bottleneck problem of multiple attributes group decision in Incomplete Interval-valued Information System(IIIS), the analysis method of incomplete interval-valued information is discussed, and the new definition of sorting quality is put forward. Combining with the Analytic Hierarchy Process(AHP), the method obtains the consistent judgment matrix, determines the decision-maker weights, and makes the synthetic security assessment for IIIS. Example analysis shows the effectiveness and the practicability of the method.
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Computer Engineering. 2011, 37(11): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2011.11.051This paper introduces the basic properties and structure of computer viruses, it can help network users to increase the understanding of computer viruses. And analyses and summarizes the development trends of computer viruses，introduces the top ten technical and developmental directions: stealth, polymorphism, social engineering, dynamic updates, blended attacks, associated data, new media, speed king, malware/trojan attacks, crossplatform. They provides valuable reference for scientific and technical personnel and anti-virus vendors to prevent computer viruses.
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Computer Engineering. 2011, 37(11): 152-154,157. https://doi.org/10.3969/j.issn.1000-3428.2011.11.052The wide-spread use of PHP in Web application development makes PHP Web application become the target of many malicious attackers. On the basis of this, through the modification of PHP interpreter and runtime libraries, the PHP Web applications can prevent SQL injection attack without the modification of the original applications. Different from traditional preventing method based on dynamic tainting, this paper uses the tainting mechanism based on trusted input tainting and SQL dialect-aware check method, solves many existing problems of traditional preventing methods. As a result, this method improves the preciseness of traditional preventing method, without any false positives. Experimental result shows that the method is precise and highly efficient, has little overhead for the PHP Web applications.
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Computer Engineering. 2011, 37(11): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2011.11.053Since existing SIR models do not accurately capture the properties of node state transition in real computer networks, this paper proposes a new SIRS computer viruses propagation model based on the principle of biological epidemic viruses. By analyzing the dynamic of this model using the theory of differential equations, it finds that the basic renewal parameter, R0, is the key factor which determines whether the computer viruses can be completely controlled. Numerical simulation results show that the model provides a good theoretical basis for the control and prediction of the propagation performance of the computer viruses.
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Computer Engineering. 2011, 37(11): 158-159,175. https://doi.org/10.3969/j.issn.1000-3428.2011.11.054The rapid development of quantum computing brings great challenges to public key cryptosystems. The braid group, which is non-commutative, provides a new platform of constructing cryptographic protocols. A convertible authenticated encryption scheme over braid group is proposed on the difficulty of conjugacy search problem and multiple conjugacy problem, in which only the designated receiver can recover and authenticate the message, when the sender repudiates the signature, the receiver can prove the dishonesty of the sender by converting the signature to an ordinary one without the cooperating of the sender. As for the resistance against quantum attacks, the proposed scheme has advantage over the schemes based on commutative algebraic structures.
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Computer Engineering. 2011, 37(11): 160-163. https://doi.org/10.3969/j.issn.1000-3428.2011.11.055A new key management scheme based on the matrix theory and the deployment knowledge is proposed. The methods of key distribution and nodes deployment are given, the process of key establishment is discussed in detail, the way of key management when the new nodes come in or the old nodes come out is introduced. Proof analysis shows that the complexity of computing and the overhead of communication of the scheme are reduced to a constant level, it has perfect security and scalability.
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Computer Engineering. 2011, 37(11): 164-166,169. https://doi.org/10.3969/j.issn.1000-3428.2011.11.056An information hiding algorithm of image fusion technology is proposed based on the improved sub-affine transformation. This algorithm preprocesses the secret information image by using the improved sub-affine transformation, increases the key of the original algorithm from six to eight, and completes hiding secret information by using image fusion technology based on Logistic chaos sequences. Experimental results show that sub-affine transformation has good scrambling effect and safety level, and Logistic chaos sequence which enhances the security of image hiding compared with traditional hiding algorithm’s blend factors have larger space.
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Computer Engineering. 2011, 37(11): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2011.11.05The current existing specifications of smart card lack effective security access control and management for the terminal access, and possibly cause some security risks in the use of smart card, including illegal input, replay attack, bypass attack, mandatory reset, and so on. In response to these security risks, this paper analyzes the application process of smart card, does some research on the feature of UCONABC access control model and gives a method of smart card access control management based on UCONABC. It embeds the subsystem of access control management into the smart card, and then writes the access control policy defined by external into the policy library file of the smart card, to realize effective access control flexibly, to ensure the secure application of the smart card. Results prove this method can be more secure to protect the real application of smart card.
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Computer Engineering. 2011, 37(11): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2011.11.058In order to solve the problems of data reduction in intrusion detection, this paper presents an algorithm of attack features selection based on mutual information including feature selection and value reduction. It uses mutual information method to eliminate the redundant features, and inductive value reduction algorithm to eliminate redundant attribute values. Experimental results demonstrate that it not only can reduce the cost of memory and time, but also can improve the accuracy of classification.
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Computer Engineering. 2011, 37(11): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2011.11.059Aiming at the file pollution problem in Peer to Peer(P2P) network, a topology building scheme is proposed to contain the spread of pollution based on immune clone topology. By analyzing the propagation model of file pollution, a neighbor nodes selection algorithm is proposed based on immunity. Simulation results show that the algorithm increases the clustering of nodes, and it can shield against malicious nodes with lower communication costs and control the spread of the pollution file in P2P network. It improves the availability of file system.
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Computer Engineering. 2011, 37(11): 176-177,183. https://doi.org/10.3969/j.issn.1000-3428.2011.11.060Traditional methods are not competent to quarantine Peer to Peer(P2P) worm in time. Aiming at this problem, this paper brings forward a fast containment method based on benign P2P worm. Benign P2P worm automatically propagates itself through software vulnerabilities. It is able to eliminate malicious worm and fix software vulnerabilities, thus it prevents the propagation of malicious worm outright. The method is efficient and has few bandwidth resources consumption. It models the method and proposes the related discrete difference model. Simulations validate the efficacy of this method.
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Computer Engineering. 2011, 37(11): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2011.11.061Laplace operator has not direction performance when conducting edge detection. Aiming at this problem, a semi-fragile watermark algorithm based on edge dectation is given under the eye vision model. It considers edge points and dark or light area when embedding watermark information. On basis of visual features of brightness and texture in the human eye, a method of image region segmentation and transform domain coefficient quantization formula are introduced to improve the image watermark transparency through dynamic vector quantization and anti-attack capability. Experimental results show that, with the amount of embedded case increasing, the algorithm of transparency and robustness are higher than the current semi-fragile watermarking algorithm.
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Computer Engineering. 2011, 37(11): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2011.11.062Based on the definitions of the unfounded set and the greatest unfounded set, it proposes a polynomial time algorithm. In the algorithm, a logic program P and one of its interpretation I are given. It evaluates the least fixed point of a monotone operator with respect to P and I, and then removes the elements in the least fixed point from the Herbrand base of P and get a set A. The set A is the greatest unfounded set with respect to I. It proves the correctness of the algorithm and analyzs its complexity.
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Computer Engineering. 2011, 37(11): 184-186,189. https://doi.org/10.3969/j.issn.1000-3428.2011.11.063The existing statistical algorithms for DNA repeats frequency have some defects on efficiency, flexibility and so on. Based on Finite State Automaton(FSA) for string multiple patterns matching, this paper constructs a DNA subsequence comparative automaton, and optimizes the automaton’s state transition based on the idea of Knuth-Morris-Pratt(KMP). By on-line scanning DNA database, it can achieve all DNA subsequence’s statistics in the whole database, including the frequency statistics of overlapped or nonoverlapped repeats and the longest common subsequence in a designated DNA sequence set. Experimental results show that the algorithm has advantages of efficiency, precise matching, flexible information acquisition, supporting on-line operation and so on.
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Computer Engineering. 2011, 37(11): 187-189. https://doi.org/10.3969/j.issn.1000-3428.2011.11.064It is difficult to determine one certain executing path because the cooperation between Agents are dynamic in a Multi-Agent System(MAS). It introduces and studies a logic based on hybrid temporal/modal logic on special Kripke models and logical properties of operation Chance Discovery(CD) via structures of defined by semantics, as the set of all formulas that are valid in all suggested models. The language chosen to build the logical formulas includes modal/temporal operations, operations for the Agent’s knowledge, local and global operations for CD, operation of local common knowledge, and an operation for chance of discovery via Agents’ interactions. Experimental result shows the problem of computing the true logical laws of is decidable at most polynomial size.
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Computer Engineering. 2011, 37(11): 190-191,194. https://doi.org/10.3969/j.issn.1000-3428.2011.11.065Aiming at the Vehicle Routing Problem(VRP) with 3D loading constraints, which contains the vehicle capacity restriction, 3D restriction, loading sequence restriction, minimum supporting area and fragility restriction, an improved tabu search algorithm is presented for this problem, including two 3D loading algorithms, two initial solutions constructing algorithms, tabu search neighbor structure and guided tabu search mechanism. Experimental results show the algorithm can solve the problem efficiently.
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Computer Engineering. 2011, 37(11): 192-194. https://doi.org/10.3969/j.issn.1000-3428.2011.11.066In order to improve the quality of speech in low Signal Noise Ratio(SNR), an improved Mel Frequency Cepstral Coefficient(MFCC) feature extraction method is proposed. On the basis of the traditional MFCC feature extraction, the improved method introduces Bark Wavelet Transform(BWT) for more suitable to human ear’s auditory system, it is used to make preprocessing before Fast Fourier Transform(FFT), on the other hand, it is used to instead of Discrete Cosine Transform(DCT) in MFCC. In the pre-processing stage Lanczos window function is adopted to restrain the side lobe and to improve the robustness. Experimental results show that compared with the traditional MFCC, the improved method can improve the speaker identification accuracy in the noisy environment.
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Computer Engineering. 2011, 37(11): 195-196,199. https://doi.org/10.3969/j.issn.1000-3428.2011.11.067On the basis of weighted 2D Discrete Wavelet Transform(2D-DWT) and Fisher Linear Discriminant(FLD), this paper presents a face recognition algorithm. It decomposes face image into level two by wavelet db2, extracts image features using FLD method for the decomposed image. The extracted features are recognized by nearest neighbor classifier. On the basis of ORL face database, experimental results show the algorithm has high recognition rate.
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Computer Engineering. 2011, 37(11): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2011.11.068This paper puts forward a method of target recognition based on multi-feature integration and polar coordinates transformation. It uses multi-feature fusion method to extract from the original image to be identified to achieve the objective dimension of compression tasks. The polar coordinate and Fast Fourier Transform(FFT) method are introduced to determine the invariant features of the transformed matrix. The targets are classified and recognized by calculating the same correlation of the characteristic matrix and the template features matrix. Experimental results show that this method has good reliability and high recognition rate.
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Computer Engineering. 2011, 37(11): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2011.11.069This paper presents a method for service name recognition based on Conditional Random Fields(CRFs) and domain rules. It choses a characteristic set by different combinations of experimental words and their part of speech. It obtains a CRFs model, and uses this model to the test corpus. It extracts service terms, which support the acquisition of service name recognition. In similarity measurement, 2-gram and edit distance mothods are adopted. Experimental results prove the validity of the method.
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Computer Engineering. 2011, 37(11): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2011.11.070Aiming at t-diagnosable multiprocessor system, this paper proposes a genetic diagnosis algorithm combining genetic algorithm and the diagnosis model. By applying the diagnosis property of the model, the quality of initial population is improved. A set of equations that estimate the statuses of the nodes in a system is proposed. Based on this, a novel fitness function is presented. Both theoretical analysis and simulation results indicate that it is a convergent and efficient algorithm.
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Computer Engineering. 2011, 37(11): 206-208,211. https://doi.org/10.3969/j.issn.1000-3428.2011.11.071According to the characteristics of order picking, taking the shortest operating time as the goal, this paper constructs the corresponding optimization mathematical model. By introducing antibody extraction and injection based on Partheno Genetic Algorithm(PGA), Immune Partheno Genetic Algorithm(IPGA) is designed to gain the optimal solution. Simulation results prove that the algorithm has better global search capability, high convergence speed and short response time, which reduces the stacker operating time and improves the working efficiency of Automated Storage and Retrieval System(AS/RS).
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Computer Engineering. 2011, 37(11): 209-211. https://doi.org/10.3969/j.issn.1000-3428.2011.11.072In order to solve the problem of low rate of success and small scale, by amending the original mapping operator and Inver-over operator and introducing differing operator, a new Evolutionary Algorithm(EA) to Traveling Salesman Problem(TSP) is got. According to the experimental results, the algorithm can find all instances’ optimal solution of experiments and the probability of getting the optimal solution is higher, while the IGT algorithm can only get that of partial instances. Comparison of variances shows the new algorithms is more stable and the T-test also shows the full advantages of the new algorithm.
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Computer Engineering. 2011, 37(11): 212-214,217. https://doi.org/10.3969/j.issn.1000-3428.2011.11.073Aiming at the problem of face feature classification, this paper proposes a new face classification algorithm based on Active Shape Model(ASM) and K-nearest neighbor algorithm. It extracts feature points of face by ASM algorithm, normalizes all feature points, and computes Hausdorff distance between feature points and every sample of each class. The face is classified by K-nearest neighbor algorithm with the Hausdorff distance computed. Experimental results show that the algorithm has high classification accuracy and speed, and it is easy to realize.
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Computer Engineering. 2011, 37(11): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2011.11.074In order to reduce the training time while increasing the sample data classification capabilities, a new approach to the problem of gait recognition based on weighted row mass vector is proposed, which uses the row mass vector as gait feature, weights it by analyzing the contribution of each mass vector element. The Normalized Euclidean Distance(NED) is used for matching and the nearest neighbor classifier is used for classifying. Experimental results on CASIA gait database show that the proposed algorithm can greatly reduce the training time and achieve high recognition rate.
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Computer Engineering. 2011, 37(11): 218-219,222. https://doi.org/10.3969/j.issn.1000-3428.2011.11.075It can reduce the error of the inertial navigation system when using Iterative Closest Contour Point(ICCP) algorithm for track matching on the gravity map, however it brings large computation costs. By modifying the activation function and false-saturating prevention function, this paper presents an improved Back Propagation(BP) neural network learning method to search for the closest contour points. Simulation results show that the algorithm improves the searching speed of the closest point and meets the matching speed and accuracy demand of gravity-aided navigation.
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Computer Engineering. 2011, 37(11): 220-222. https://doi.org/10.3969/j.issn.1000-3428.2011.11.076By combining group searching characteristic of Genetic Algorithm(GA) and local searching characteristic of quasi-Newton method, this paper proposes a hybrid localization algorithm for Time Difference of Arrival(TDOA). GA iterates globally until the satisfactory convergence value is achieved, and the value is used as the initial value of quasi-Newton iteration. The iteration process continues until the exact solution is get. So the hybrid algorithm overcomes the shortcomings that quasi-Newton method has high sensitivity to initial point and GA has low search efficiency in later period. Experimental results show that if the parameters are assumed reasonably, the hybrid algorithm has higher stability, localization rate and localization precision than GA and quasi-Newton method.
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Computer Engineering. 2011, 37(11): 223-224,227. https://doi.org/10.3969/j.issn.1000-3428.2011.11.077To decrease the computational complexity of image deblurring, this paper proposes a new deblurring algorithm. This method divides the original image into several sub-blocks and incorporates the anti-reflective boundary conditions, which overcome the discontinuity of the normal derivative brought about by other boundary conditions. Numerical experiments show that the new developed algorithm, by using proper sub-blocks and width of the bound, outperforms the original one with respect to the time used.
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Computer Engineering. 2011, 37(11): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2011.11.078High-resolution image using Projections Onto Convex Sets(POCS) method often appears the phenomenon of decline in the quality edge. To solve this problem, this paper proposes a super-resolution reconstruction method, introduces Fourier transform method to solve the image registration process to obtain the displacement error, uses Laplace edge detection operator to remove the edge of the shock. Experimental results show that super-resolution reconstruction method based on edge detection can obtain high quality images.
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Computer Engineering. 2011, 37(11): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2011.11.079Because phase correlation method has strong anti-interference ability of light, this paper proposes an extended phase correlation registration method. According to the peak distribution characteristics of phase correlation function, the sub-pixel registration is achieved by multi-peak fitting. Experimental results show that the method overcomes the shortage of traditional method that it can only get integer pixel registration, and has strong robustness and high efficiency.
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Computer Engineering. 2011, 37(11): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2011.11.080This paper presents a interactive local deformation method based on skeleton node constraint by using generalized meatball deformation. The method extracts the skeleton nodes of the polygonal mesh models, employs the skeleton structure to determine the local field which the skeleton nodes influence. It computes the Euclidean distance between mesh vertices and skeleton nodes. The maximum Euclidian distance is constraint radius, calculates the potential function for these vertices. The update position of the mesh vertices is computed by handling the space coordinate of the skeleton node. Experimental results show that the method can maintain the local feature of the polygonal mesh models and guarantee the intuitive and efficient of model deformation.
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Computer Engineering. 2011, 37(11): 234-236,239. https://doi.org/10.3969/j.issn.1000-3428.2011.11.081This paper assesses the fingerprint image quality by combining spatial and frequency features. The valid area is separated from original fingerprint image, and the size of valid area, deflect, dry or wet extent and others other local quality indices. By Fourier spectrum analysis, a global quality index is adopted. And a weighing nonlinear fusion approach is addressed to achieve comprehensive evaluation of the final quality. Experimental results demonstrate that the algorithm can effectively evaluate the quality of fingerprint images and can significantly improve the performance of automatic fingerprint recognition system.
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Computer Engineering. 2011, 37(11): 237-239. https://doi.org/10.3969/j.issn.1000-3428.2011.11.082Aiming at the problem that traditional vector recognition algorithm has and low recognition efficiency, this paper uses a new method to recognize the digitized curves which is based on sparse pixel traversal tracking fitting algorithm. The algorithm operations with orthogonal pixel tracking style to obtain key points data of graphics area, then the obtained points are used to make curve fitting to uniformly perform the recognition of line segments, circles and arcs, et al. Experimental results show that this algorithm is more efficient and effective compared with conventional methods, especially on the consumed time and space.
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Computer Engineering. 2011, 37(11): 240-241,244. https://doi.org/10.3969/j.issn.1000-3428.2011.11.083Aiming at schedule problem, as well as its visual simulation, for the regional pump station in urban drainage system, this paper puts forward an optimized strategy of regional pump station schedule designed by the fuzzy control thought, with the starting point of controlling an in-out balanced flow of pump station, then establishes the Colored Petri Net(CPN) model for optimal scheduling of the regional pump station, which is based on the CPN theory and combined with drainage scheduling optimization process. Simulation results of this model dynamic process, which is simulated by the CPN Tools, show that it is consistent with the law of drainage schedule control and state space analysis's outcome, and furthermore it gives a new way to the parameters visualization of the dynamic process within regional pump station schedule.
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Computer Engineering. 2011, 37(11): 242-244. https://doi.org/10.3969/j.issn.1000-3428.2011.11.084This paper designs a embedded Reduced Instruction Set Computer(RISC) Central Processing Unit(CPU) based on Field Programmable Gate Array(FPGA) platform. The instruction set is designed refer to Microprocessor without Interlocked Pipeline Stage(MIPS) instruction set principle. By analyzing the process of each instruction, the 5-stage pipeline of embedded CPU is built. It adopts data forwarding technology and software compiler method to solve pipeline-related problem. The key modules of CPU: Arithmetic Logic Unit(ALU), control unit, instruction cache are designed. Verification results show that the embedded RISC CPU speed and stability meet the design requirements.
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Computer Engineering. 2011, 37(11): 245-247. https://doi.org/10.3969/j.issn.1000-3428.2011.11.085According to the operation requirement of coal transportation and blending in thermal power plant, an intelligence monitoring system of thermal power plant is proposed and whose architecture is designed four parts: iFIX subsystem, optimization control subsystem, video surveillance subsystem and database management subsystem. The procedure and function of three important processes, namely, Programmable Logic Controller(PLC) control, iFIX configuration and optimal control, are discussed in detailed. A set of fault diagnose strategy for equipment based on fuzzy decision-making and an operation schedule for coal blending based on Genetic Algorithm are established. Using Visual C++ programming language, the optimization control subsystem and communication module are realized. Practical application indicates that automatic transportation and intelligence blending can be achieved by the system and its design is reasonable, reliable and available.
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Computer Engineering. 2011, 37(11): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2011.11.086Texas Instrument released its fixed point production of TMS320C6455, which is favored by many users, as its abundant peripheral resources. The design makes use of its Ethernet peripheral module EMAC realizing the User Datagram Protocol(UDP) stack. It adopts an original method instead of the traditional way, which is relied on the socket. With the reduction of unnecessary part in socket, it achieves high performance of receiving and transmission by the stack developed by ourselves and provide standard interface of functions according with socket. Simulation results of this stack are given and it indicate the stack has many merit such as simplification, high performance, modification convenience.
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Computer Engineering. 2011, 37(11): 251-252,256. https://doi.org/10.3969/j.issn.1000-3428.2011.11.087In the satellite positioning, the time correction of reference station is considered generally as a fixed number, but in actually, the time correction of reference station is considered changed along with the time. For this, a method of time correction estimation is put forward and the time model is corrected with three parameter. The time correction error of reference station can be got through using ephemeris data, supposing the moving-target as siger model and introducing the Kalman filtering algorithm. The time correction of reference station is accurately estimated. The results demonstrate that the positioning accuracy is advanced largely.
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Computer Engineering. 2011, 37(11): 253-256. https://doi.org/10.3969/j.issn.1000-3428.2011.11.088According to the faults of the real-time performance in Linux2.6 kernel, this paper uses one-shot mode to refine the clock granularity, realizing the clock time at microsecond level, proposes classification CSBOT schedule algorithm based on the threshold. According to the different load conditions, it respectively uses LSF algorithm and key/emergency degree preferred algorithm to achieve the light load of high efficiency and system performance of the system when the system overloads elegant relegation, at the same time, introduces threshold preemptive strategy to reduce thrashing phenomenon caused by LSF, improves the efficiency of the system.
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Computer Engineering. 2011, 37(11): 257-259,274. https://doi.org/超宽带；交织器；正交频分复用；标准兼容；现场可编程门阵列This paper designs a interleaver which is used in Ultra Wide Band(UWB) system. The interleaver is based on the structure of two port Random Access Memory(RAM) and address generator, it can be compatible with standards of Multi Band-Orthogonal Frequency Division Multiplexing(MB-OFDM) and Dual Carrier-Orthogonal Frequency Division Multiplexing(DC-OFDM). To compare with the interleaver applied to only one standard, this interleaver just increase 4.5% and the registers increase 1.8%. The main clock frequency is 132 MHz and the max throughput is 1.42 Gb/s, and it meets the requirement of UWB system.
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Computer Engineering. 2011, 37(11): 260-263,271. https://doi.org/10.3969/j.issn.1000-3428.2011.11.090According to the specific work environment and the alignment accuracy of Autonomous Underwater Vehicles(AUV), a modified two-position integrated alignment based on Kalman filtering is proposed in this paper. The inertial navigation error model is built and the principle of two-position alignment is analyzed. The systematic observability is improved by changing the strapdown matrix. The degree of observability for Strap-down Inertial Navigation System(SINS) is computed in the context of two-position alignment scheme using the spectral condition number theory. Simulation results show that the device errors can be estimated by the novel two-position alignment, and greatly improve the alignment precision
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Computer Engineering. 2011, 37(11): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2011.11.091Aiming at R/W of FRAM device nodes in ARM9 based embedded Linux and its application related problems, the detailed embedded Linux; Ferroelectric RAM(FRAM) drive design and implementation of the pretreatment, R/W and control mechanism is proposed based upon Linux systematic standard, after deeply studying Linux drive design and the working principles and hardware characteristics of FRAM as well. The implementation approach of FRAM low level driver based on memory addressing mode in kernel is adopted, and it proves the feasibility and stability of the driver during data being stored and transported.
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Computer Engineering. 2011, 37(11): 267-268,277. https://doi.org/10.3969/j.issn.1000-3428.2011.11.092Multi-target direction estimation of a single vector sensor is studied mainly in the conditions of alpha stable distribution. Spectral measure presentation and spectral measure estimation method of multi-dimensional characteristic function of stable distribution are introduced. On this basis, it is derived that orthogonal components of output speed of single vector sensor meets spectral measure presentation equation of characteristic function, to establish the corresponding relationship between spectral measure and target direction estimation and to estimate spectral measure with the characteristic function method or the 1D projection method, then direction of arrival and the number of the target source are estimated. Simulation results show that in the alpha stable distribution assumption, multi-target direction estimation method is more reasonable and effective based on the spectral measure.
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Computer Engineering. 2011, 37(11): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2011.11.093The upper bound of the price of anarchy for general network with oblivious users is investigated by algorithmic game theory. The variational inequality model is established to describe the selfish routing with oblivious users. The upper bound of price of anarchy is derived by analytic derivation. It shows that the upper bounds depend on the link travel time functions and the ratio of the oblivious users in the network. The upper bound of price of anarchy with the polynomial link travel time functions of selfish routing with oblivious users is obtained; the relation between this result and the results in the previous literature is compared.
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Computer Engineering. 2011, 37(11): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2011.11.094Aiming at the issue of the traditional fixed-point algorithm’s sensitivity on the initial value of the separation matrix, an improved Independent Component Analysis(ICA) algorithm is proposed. The algorithm has a low dependence on the initial value by referring the search factor in the core iterative process of the traditional algorithm, and the method improves the efficiency of the algorithm. The mixed spectral information is separated by using traditional fixed-point algorithm and improved fixed-point algorithm. Experiments show that the improved ICA algorithm decreases iterations by 26% with the considerable spectral classification effect to the traditional algorithm, and improves the separation efficiency of independent component, thus it is an effective crop spectral classification method.
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Computer Engineering. 2011, 37(11): 275-277. https://doi.org/10.3969/j.issn.1000-3428.2011.11.095In the pervasive computing environments, the diversity of the device interfaces leads to the phenomenon that interactive semantics communication and presentation is getting increasingly complex on various devices, resulting in difficulties in the interoperability of heterogeneous devices. From the point of users’ view, interactive semantics is the information content which can be seen in the interfaces and can be controlled by the users. The invariability of the information contents makes it possible to interoperate between heterogeneous devices. Based on XML, a device- independent interactive semantics transmission protocol——GISTP, is designed and implemented, which is used to communicate and represent the information content in the main window of the interface, and the availability and effectivity of the protocol are illustrated by a case study which implements GISTP interpreters on different devices.
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Computer Engineering. 2011, 37(11): 278-280. https://doi.org/10.3969/j.issn.1000-3428.2011.11.096An attempt is made to apply C-W algorithm, which is usually used in routed optimization in the domain of distribution, to purchase logistics，and the research focuses on unexpected tasks that may be occurred in the process of transportation timely and intellectually. In view of the characteristic of transported products in the purchase logistics of assembly enterprises, the task is divided into initial tasks and unexpected tasks. The former adopted C-W algorithm to vehicle capacity and volume as dual constraints is inserted. The latter is used autonomous vehicles competitive bidding independently, which can obtain the optimal solution and solve unexpected tasks timely and intellectually. An example is given to confirm the service ability of C-W algorithm in distributing the initial tasks and autonomous vehicles competitive bidding independently and a good result is obtained.
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Computer Engineering. 2011, 37(11): 281-282,287. https://doi.org/10.3969/j.issn.1000-3428.2011.11.097This paper proposes an adaptive screen capturing algorithm MDAC. MDAC takes the advantage of mirror driver to capture the changes of the screen, and chooses image coding algorithm adaptively according to the update frequency of the changed area. Experimental result shows that MDAC can reduce the CPU burden and file size greatly while maintaining high image quality.
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Computer Engineering. 2011, 37(11): 283-284. https://doi.org/10.3969/j.issn.1000-3428.2011.11.098In order to shorten the test cycle and reduce the programming complexity of conventional test methods by calling the interfaces of Linux kernel and drivers directly, this paper presents a scheme that Lua script language is embedded into Linux kernel to test kernel and drivers. Moreover, the simple Linux kernel test tool is designed and implemented. Experimental results show that this tool only spends a little of Linux kernel space, and it is flexible and convenient. It can accurately and effectively complete the test for kernel and drivers.
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Computer Engineering. 2011, 37(11): 285-287. https://doi.org/10.3969/j.issn.1000-3428.2011.11.099One of the aims of China custom is to manage enterprise in way of network and information. On the basis of research on custom supervision mode and specifications of business process, supervision network system based on Web is designed which meets expectations of custom administration and enterprise. This system adopts J2EE as distributed development platform, implements the multi-tier architecture with separation of business logic and data. Test running results show that this system has well reliability and extension.
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Computer Engineering. 2011, 37(11): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2011.11.100The major network virtual communities only provide limit means of interactions and cannot satisfy the real-time communication requirement. With the concept of mixed reality teaching and learning environment, a powerful 3D virtual reality community platform with Web3D interactivity, WonderSCUT, is developed, which is based on project Wonderland. WonderSCUT supports a rich family of communication methods, resulting strong immersion and effective interaction. WonderSCUT also provides good scalability and strong security. Experimental results show the advantage of this platform. WonderSCUT meets the trend of Web3D interactivity, and is promising for both research and application.
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Computer Engineering. 2011, 37(11): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2011.11.101Program writing can essentially influence the pre-processing of g-factor flight data at centre of gravity of aircraft before being applied in structure fatigue life accessing. So reasonably setting pre-processing procedure sequence is necessary. Main contents of each procedure are determined such as: wiping off acute noise data, wiping off points between peak and valley, modifying system zero draft, modifying g-factor data according to instant fuselage mass, getting rid of invalid data, etc. The influence between these procedures is analyzed. The demand of procedure sequence and the corresponding reasons are presented. And proper processing plans in some data processing methods are suggested. It is proved that the program obeyed the suggested plan presents satisfactory efficiency and gives valid processing results.
2024
Volume 50 No 9
Volume 50 No 9
(Started in 1975, Monthly)
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
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