05 January 2011, Volume 37 Issue 01
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Computer Engineering. 2011, 37(01): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2011.01.001Network coding is a new technique in recent years, which can increase the bandwidth efficiency and security of communication, and reduce the wastage of energy. This paper creates a wireless network model. The model includes one source and several sinks. The design of ACK/NAK lost is considered in this model, two packet broadcast schemes using network coding or not are presents. Compared whih two packet broadcast schemes, one scheme retransmits the lost packets using network coding, the other does not use. Theoretical analysis and simulation result show that network coding can decrease the number of transmissions significantly, enhance transmission efficiency.
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Computer Engineering. 2011, 37(01): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2011.01.002The method is stemmed from the assumption that each data set is a probabilistic realization of an underlying multinomial distribution under a partition on sample space. With the MLE of model parameters, the underlying distribution of a data set can be approximated by a discretized probability distribution. With the generalized Fisher metric on multinomial manifold with boundary, the information divergence between underlying models can be approximated by the corresponding divergence between estimated distributions, it provides the necessary element for unsupervised learning on information manifold. The natural separation of original data sets can be visualized when the dimension of reduced space is two or three. Experimental result shows that the method can be applied to visualization of big sample data sets or color image data sets.
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Computer Engineering. 2011, 37(01): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2011.01.003The bilateral multi-issue negotiation problem with complete information is researched, and a counteroffer decision-making model for the proposer is put forward. In each round, the proposer gives the counteroffer according to the model that makes the proposer’s utility under a certain satisfied level and optimizes the utility of the other side, which makes the outcome of negotiation to be Pareto optimal. It makes experimental analysis under different concession strategy of both sides, which may provide a theoretical reference for the negotiation between two co-operation sides with complete information
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Computer Engineering. 2011, 37(01): 10-12,15. https://doi.org/10.3969/j.issn.1000-3428.2011.01.004Aiming at the uncertain factors and the complexity of modeling in military operations, an operational effectiveness evaluation model is proposed. Using rough set theory removes redundant evaluation index and reduces the time and space complexity of Naive Bayesian classifier(NB). An algorithm of the assessment model is put forward. Through the Bayesian network parameter learning, different data types of assessment indexes are expressed in the class conditional probability distribution uniform. This way can not only guarantee the objectivity of the assessment but also express the randomicity of battle process. Instance research shows that the method used to assess the effectiveness of combat operations is feasible.
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Computer Engineering. 2011, 37(01): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2011.01.005In Peer-to-Peer(P2P) Video-on-Demand(VoD) system, the nodes usually have quite different service capabilities. How to make full use of various types of nodes’ capacity is a problem worth studying. From the amount of data requested point of view, this paper proposes a Bandwidth Adaptive Schedule(BAS) strategy to enhance the usage of peers’ bandwidth. When peer detects it has additional downlink bandwidth, it performs additional schedule to peers who have additional uplink bandwidth. By this, data pieces can spread more quickly in the system so that the bandwidth pressure of the server can be reduced. Simulation experimental result shows that the stratgy improves the overall performance of P2P VoD system.
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Computer Engineering. 2011, 37(01): 16-18,21. https://doi.org/10.3969/j.issn.1000-3428.2011.01.006The idf function of traditional tf.idf algorithm can only evaluate the ability of features to discriminate different documents in a macroscopically way, which can not reflect the differences of distribution proportion for features in each document and each class of the whole training set, it reduces the accuracy of text representation. To solve the above problem, this paper proposes an improved feature weighting method called tf.igt.igC. This method begins from analyzing the characteristics of feature distribution, through introducing the concept of information gain in the information theory, realizes the comprehensive consideration of the two specific dimensions of feature distributions, and overcomes the shortcomings of the traditional formula. Experimental results on the two open source corpus show that compared to other two feature weighting methods, tf.igt.igC is more effective in terms of calculating the feature weighting.
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Computer Engineering. 2011, 37(01): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2011.01.007Radar network detection performance is studied under distributed jamming, and is described by radar network detection probability. The 3D radar network detection model is created using hardware accelerated based on isosurface extraction and the 3D model is rendered on 3D virtual battle field. Experimental result shows that the radar network detection performance is represented dynamically, it can assist radar network design, jammers scheme, counterwork training and so on.
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Computer Engineering. 2011, 37(01): 22-23,27. https://doi.org/10.3969/j.issn.1000-3428.2011.01.008Aiming at the conditions that the probability of sending and receiving signals is random number, this paper considers the number modeling of stations, and proposes an approach to model station numbers based on Beta-Binomial-Poisson model. Parameter estimation is given and the method by computer simulation shows effectiveness.
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Computer Engineering. 2011, 37(01): 24-27. https://doi.org/10.3969/j.issn.1000-3428.2011.01.009This paper implements many trials with three clustering algorithms and three metrics in seven data sets for assessment of clustering performance with these factors. It suggests a selecting exemplar algorithm for identifying the clustering parameters. Experimental results show that the metric Root Mean Square Deviation(RMSD) is better than other metrics. The algorithm SPICKER is better than others, and the AP clustering algorithm is in the next place.
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Computer Engineering. 2011, 37(01): 28-30,33. https://doi.org/10.3969/j.issn.1000-3428.2011.01.010
In argumentation-based negotiation, how to express the architecture of the negotiation Agent is a critical problem. This paper proposes a novel cognition and decision model is proposed to be used in electronic commerce negotiation, which consists of the architecture of both buyer and seller Agent. It uses sets of both its own goal and its counterpart’s information to express the knowledge of negotiation Agent. Furthermore, a multi-objective model is proposed to assist the decision process. An instance of argumentation-based negotiation is provided to verify the application of the model.
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Computer Engineering. 2011, 37(01): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2011.01.011To detect community structure in complex networks, modularity density function is optimized. By optimizing process, how to optimize the D function can be reformulated as a spectral relaxation problem and a spectral clustering algorithm is proposed. Furthermore, the time complexity of algorithm is analyzed. The approach is illustrated and compared with direct kernel approach based on modularity density and spectral clustering based on modularity by using a classic real world networks. Experimental results show the significance of the proposed approach, particularly, in the cases when community structure is obscure.
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Computer Engineering. 2011, 37(01): 34-35. https://doi.org/10.3969/j.issn.1000-3428.2011.01.012Based on the analysis of popular database performance test standards, this paper generalizes the requirements of database performance test tools, introduces a Remote Procedure Call(RPC)-based general database performance testing tool architecture. The architecture also considers the interactivity with user interface and implements an asynchronous call mechanism.
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Computer Engineering. 2011, 37(01): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2011.01.013By using the actual different hierarchical levels of memory and computational units in parallel architectures, this paper proposes a multilevel parallel algorithm to solve a structured linear system with a symmetric Toeplitz matrix. By means of the appropriate mathematical derivation, a symmetric Toeplitz linear system is translated to a Caucky-like linear system. The algorithm is realized by Message Passing Interface(MPI) and Open Multi-platform shared-memory parallel Programming(OpenMP). Experimental results verify its feasibility.
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Computer Engineering. 2011, 37(01): 39-40,44. https://doi.org/10.3969/j.issn.1000-3428.2011.01.014This paper proposes a test cases generation framework based on Model-Driven Architecture(MDA), in which Platform-Independent Model(PIM) is converted into a Platform-Independent Test(PIT) model through level conversion, and platform-independent test model is converted into the corresponding test cases through vertical conversion. MDA conversion tools including ATL and MOFScript are used to develop the corresponding transformation rules acting on the meta-model, so that testers only need provide source model and test data to generate the corresponding test cases.
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Computer Engineering. 2011, 37(01): 41-44. https://doi.org/10.3969/j.issn.1000-3428.2011.01.015The Multi-method Collaboration Optimization(MCO) is more useful in the overall design process of complex product, but the design and implementation of multi-optimization algorithm is still a challenge in this area. Based on the analysis of object-oriented component technologies, the component-based design method of optimization algorithm is presented. The interface specification and operational mechanism of optimization algorithm component is put forward. Aiming at algorithm schedule needs of method collaboration, this thesis proposes the directed graph-based algorithm schedule method using the reference of graph schedule in parallel computing area.
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Computer Engineering. 2011, 37(01): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2011.01.016In the process of protocol conformance test, the spread of non-conformance leads to two problems: low efficiency and actual range of test being reduced. In order to solve these problems, a progressively dynamic protocol conformance test method is proposed, in which test case is executed progressively, and the result of the execution is used as guidance to the subsequent test case. In this method, influence of the spread of non-conformance is reduced, the efficiency of the execution of the test suite is improved and the actual range of the protocol conformance test is expanded.
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Computer Engineering. 2011, 37(01): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2011.01.017Parallel coordinates can be used in high-dimensional data visualization, but when the data dimension to be displayed is too large, visual clutter may occur. This paper proposes a data visualization method named PPCP, which combines Principal Component Analysis(PCA) and parallel coordinate. PCA is used for effective dimension reduction on high-dimensional data, and the processed data are displayed in the way of parallel coordinate visualization. Experimental results show that it is effective to reveal the relationships among high-dimensional data.
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Computer Engineering. 2011, 37(01): 51-53,56. https://doi.org/10.3969/j.issn.1000-3428.2011.01.018This paper designs a fault-tolerant mechanism that uses state machine to solve five kinds of the knowable faults, including disaster, disk error, running environment error, system error and network error, which exist in Remote Mirror System(FRM) based on FreeBSD. It is proved to be stable enough to ensure the data integrality and consistency when fault occurs. And it can help FRM surviving against multiple faults and continue its task of data protection.
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Computer Engineering. 2011, 37(01): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2011.01.019This paper proposes logistic saturated growing model and (M, r) saturated growing model, which overcome the uncertainty of initial network about BA model. Besides, two kinds of saturated growing models are more in accordance with real networks about the growth of edges than BA model. Using Markov chain approach to analyze two models, it obtains matrix iterative formula of node degree distributions. Through numerical calculation, results show that their node degree distributions are subject to power law with decay index -3.25 and -3.18 respectively. In addition, it makes computer simulation of algorithms, and simulation results show the correctness of the theoretical analysis and the time dependence of node degree distributions.
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Computer Engineering. 2011, 37(01): 57-59,62. https://doi.org/10.3969/j.issn.1000-3428.2011.01.020This paper puts forward a clustering on mass Chinese short message texts technique based on semantic concept. The method starts from the Chinese short message itself, it uses classified hierarchy Subject Word of Thesaurus of Modern Chinese, then abstracts conceptional tuple from short message text, forms clustering result expressed by high-leveled concept, based on which these samples are divided, thus the whole clustering process is completed. Experimental result shows the clustering algorithm achieves a satisfactory clustering result and a better executive efficiency as well.
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Computer Engineering. 2011, 37(01): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2011.01.021In solid modeling, due to the existence of singular features, feature based data exchange is blocked. Aiming at this problem, an exchange approach for singular features based on geometry operations is presented under the feature exchange framework. It realizes singular feature exchange by transforming it into a group of geometry operations, which are equal to the singular feature. Experimental results show that the method can solve the problem of singular feature exchange among heterogeneous CAD systems effectively.
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Computer Engineering. 2011, 37(01): 63-64,68. https://doi.org/10.3969/j.issn.1000-3428.2011.01.022According to the problems in the use of Lung Image Database Consortium(LIDC) database in lung cancer computer aided diagnosis research, such as the lack of unified data model and the mechanism of data validity to warrant the consistency and union of data, this paper proposes an improved data model with XML technology. The design scheme of an integrated tool including main classes and the realization of its key problems are explained and analyzed. Practice shows that the tool has the ability to visualize and retrieve lung nodule as well as to evaluate the nodule detection algorithms, and it can improve work efficiency of researchers.
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Computer Engineering. 2011, 37(01): 65-68. https://doi.org/10.3969/j.issn.1000-3428.2011.01.023Formal methods and runtime monitoring both are very effective way to improve the software reliability, but have many limitations like weak ability of expressing requirements and code scattering. Aiming at these problems, Formal Monitoring-based Trusted Software Programming Model(FM-TSPM) is proposed in the paper, which combines the advantage of the formal method and the runtime monitoring, achieving the integration of Interdisciplinary approaches. System requirements are expressed using formal specifications. Efficient monitoring code is automatically generated according to the specifications, solving the code scattering problem. It weaves the monitoring code and the source code together, so as to inject monitoring ability to the software.
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Computer Engineering. 2011, 37(01): 69-71. https://doi.org/10.3969/j.issn.1000-3428.2011.01.024In order to improve test quality and test efficiency, the developed tree model test case generation algorithm is raised based on the theory of covered pair-wise combination of all the interface parameters, which considers the system influence of the extern interfaces and all possible values comprehensively. It is proved that the time complexity and space complexity of the algorithm are effectively reduced. By means of the test analysis on CTCS-2 train control center software test platform, the test efficiency and quality can be improved greatly by the algorithm.
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Computer Engineering. 2011, 37(01): 72-74. https://doi.org/10.3969/j.issn.1000-3428.2011.01.025Aiming at the traditional viewpoint that NFS protocol is unsuitable for the deployment of the database, this paper analyzes the factors that affect database performance and the I/O features of the relational database, and discusses that the new features of NFS V4 protocol(such as COMPOUND RPC process) can meet the requirement of database I/O performance. File system with good performance can help improving performance of database. Experimental result verifies that the way relational database deploys in Network Attached Storage(NAS) based on NFS V4 protocol is feasible and promising.
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Computer Engineering. 2011, 37(01): 75-77,80. https://doi.org/10.3969/j.issn.1000-3428.2011.01.026Existing direction relation representation method can not represent the internal spatial direction of the minimum bounding box. Aiming at this shortage, this paper presents a 3DR44 direction relation representation model. It gives the dynamic direction adjacent relations and the bidirectional mapping relations of the 3DR44 direction relations model. The orderly sequences of the intersection pairs are used to deal with and distinguish the complex direction relations. The direction relations model in the 2D space can be used to handle the 3DR44 direction relations in the 3D space. Application results show that the model can enhance the ability to represent the 3D direction relation of the spatial database.
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Computer Engineering. 2011, 37(01): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2011.01.027A new retrieval algorithm for English texts is proposed. Keywords are extracted from the English texts. The state matrix of keywords is calculated based on transition probabilities matrix and the first singular value vector is got through Singular Value Decomposition(SVD) as the complex feature vectors. The cosine similarity of texts is used to measure the similarity between the query and documents. Experimental results indicate that this algorithm gets the advantage over the traditional LSA algorithm in precision and computational efficiency.
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Computer Engineering. 2011, 37(01): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2011.01.028Borda voting method is adopted in meta search engine. It is based on the relationship between position taken by the linear decrease in the allocation of the relevant rules to score the results. Mechanical distribution of scores affect the results of the sort. According to its default, this paper presents an improved Borda voting algorithm, which calculates the similarity of query string with each result and similarity as the result of the relevant scores. Experimental results show that the precision of improved algorithm is better than Borda voting method.
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Computer Engineering. 2011, 37(01): 84-86,89. https://doi.org/10.3969/j.issn.1000-3428.2011.01.029This paper introduces the concepts of software verification and software validation and their relationships. It uses a Management Information System(MIS) development project as an example to describe the specific implementation of the verification and validation activities in software development life cycle, studies how to make verification and validation activities cooperated with the whole life cycle of the project, and how to combine with the project entity associated. It is verified that software verification and software validation are effective methods to guarantee the qualification of software productions.
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Computer Engineering. 2011, 37(01): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2011.01.030
In order to meet the demand of channel quality estimation in satellite communications, a channel quality estimation algorithm is proposed in the condition of AWGN channel, while Signal to Interference plus Noise Ratio(SINR) playing as the channel quality parameters. Based on the analysis of moment estimation method and decision data estimation method in theory and smoothing the power of noise plus interference while adopting exponential weighting factor, this paper estimates SINR by combining moment estimation and decision data estimation linearly and analysis mean square error of the model while searching the optimal exponential weighting factor. Through the computer simulations, this improved algorithm’s RMSE decreases obviously comparing with existing algorithm and pilot data and “warm-up period” is unnecessary when the actual SINR ranges from -5 dB to 20 dB.
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Computer Engineering. 2011, 37(01): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2011.01.031Missing value of sensory data often occurs in Wireless Sensor Networks(WSN). This paper proposes a distributed algorithm named SC, which consists of two approaches named SRS and CNI. The algorithm SC chooses CNI or SRS dynamically according to the number of child node of current node. The theory analysis shows that SC does not increase extra energy. Simulation results show that SC can get perfect accuracy and adaptability in different topology.
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Computer Engineering. 2011, 37(01): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2011.01.032Aiming at the Wireless Sensor Networks(WSNs) with data redundancy, based on the Differentiated Service(DiffServ) mechanism with loss and preemptive high-priority real-time data frame, the non-real-time data frame is regarded as class I customer, the real-time data frame is regarded as class II customer. Considering the finite buffer capacity, a discrete-time queueing model with two classes of customers is built, by using the method of two-dimensional Markov chain, the steady state probability distribution of the queueing model is derived, formula for the performance measures are given. Numerical results are provided to demonstrate the influence of system parameters on the system performance mathematically.
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Computer Engineering. 2011, 37(01): 96-97,100. https://doi.org/10.3969/j.issn.1000-3428.2011.01.033Chord is a kind of structured P2P network, but the route table in Chord only covers half of the identifier space. As long as target node is in the half ring which is not covered by the route table, the target node must be found via no less than one medium node, namely, two hops. So, Chord is not very efficient. A stratum route model for Chord(S-Chord) is proposed. By logically constructing inter-domain transmitting network on Chord, the target node which is not in the same half ring with the originating lookup node can be found in only one hop. The covering problem of Chord route table is solved better. Simulation experiments show that S-Chord can reduce the average lookup path length and get higher efficiency.
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Computer Engineering. 2011, 37(01): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2011.01.034Through analyzing the current packet loss recovery on voice and video transmission, this paper proposes a Binomial Probability Model(BPM) based on the Forward Error Correction(FEC) Reed-Solomon(RS) redundant coding and the interweaving packet loss recovery technique. BPM calculates the number of redundant packets according to the feedback from the receiver. By using interweaving technique to transmit mixed-packet of voice and redundancy, BPM can save bandwidth effectively. Experimental result shows that BPM is able to encode enough redundant packets under bad network condition, which ensures the receiver to decode the original data by using these packets and display it, and the equality of transmission and playing is improved greatly.
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Computer Engineering. 2011, 37(01): 101-103,106. https://doi.org/10.3969/j.issn.1000-3428.2011.01.035
Environmental parameters of farmland are essential agricultural information, while Wireless Sensor Network(WSN) provides a fine- grained way to perceive the information. In transmission of sensor data along wireless network in farmland, there is much worse link quality than bare land and overall low delivery rate, which brings great difficulty to accurate collection of information in time. This paper introduces two link estimator factors named average continuous successful transmission count and late continuous successful transmission count, based on overall stability and locality of wireless links quality of farmland. The results of network simulation of a route algorithm integrating with the factors shows an effective enhancement of overall packet receive rate.
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Computer Engineering. 2011, 37(01): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2011.01.036A cross-layer design of adaptive multicast transmission system based on Type-Ⅲ HARQ is proposed. This paper combines Type-Ⅲ HARQ at the data link and Adaptive Modulation and Coding(AMC) schedule at the physical layer. The curve fitting method of packet error rate is used to compute the adaptive threshold in order to maximize spectral efficiency when under given constraint. The closed-form expressions of the average spectral efficiency of multicast transmission in cross-layer design and layered design are derived. Simulation results show that this cross-layer design can improve obviously in spectral efficiency comparing to the layered design and Type-ⅡHARQ, and spectral efficiency increase with the max- transmission time grows.
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Computer Engineering. 2011, 37(01): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2011.01.037This paper refers TIGER database, builds a realistic road map as simulation scene. It evaluates the applicability of three routing protocols including AODV, DSR and DSDV in Vehicular Ad-hoc NETwork(VANET) by the joint simulation of Simulation of Urban MObility(SUMO) traffic simulator and NS2 network simulation platform. Experimental results show that existing routing protocols exist the shortages of low packet transmission success, high normalized routing load and big average end-to-end delay under urban VANET environment, it can not meet the needs of existing VANET communications in urban scenarios, and needs developing new routing protocol.
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Computer Engineering. 2011, 37(01): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2011.01.038This paper analyzes the relation of node residual energy overlapping sensing coverage rate and cluster head selection from the angle of ensuring Wireless Sensor Network(WSN) perception covering performance. It improves the information gathering process before selecting cluster head threshold, and presents a Wireless Sensor Network(WSN) clustering algorithm which is suitable for high-density random deployment. Experimental result shows that this algorithm can preserve the network sensing coverage rate effectively, and it can prolog network lifetime.
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Computer Engineering. 2011, 37(01): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2011.01.039Aiming at the problems of heterogeneity and degree constraint of node in application layer multicast, this paper proposes a resource uniform distribution scheme based on multiple description coding. The uniform distribution of sub-descriptions among nodes is achieved with distributed algorithm in terms of the cited time and the numbers of copy. The request set is acquired by weighted selection algorithm, then the load of nodes is balanced. Simulation results demonstrate that the scheme can lower the impact of nodes departure, and it has high scalability and robustness.
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Computer Engineering. 2011, 37(01): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2011.01.040Aiming at the problem of the lack of a backbone network in Wireless Sensor Network(WSN), this paper proposes a virtual backbone network construction algorithm based on connected dominating set. The algorithm uses the maximal independent set and the connected dominating set of graph theory to construct a virtual backbone network, and uses the pruning rule to remove redundant nodes. The algorithm preferably selects more energy and closer nodes, which makes the network life longer and the delay smaller. Experimental result shows that in unit disk graphs the connected dominating set generated by the algorithm is at most 7.6opt+1.4, and the message complexity and time complexity are O(n).
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Computer Engineering. 2011, 37(01): 119-121,124. https://doi.org/10.3969/j.issn.1000-3428.2011.01.041Aiming at the problems of low efficiency to find redundant nodes in classical Coverage-Preserving Node Scheduling Scheme(CPNSS) of the Wireless Sensor Network(WSN), this paper considers the situation that nodes have different sensing ranges in actual network and proposes a Generalized Efficient Coverage-Preserving Node Scheduling Scheme(GECPNSS). The algorithm builds extended node network model, analyzes different cases that how the nodes and their neighbors are located and improves the central angle calculation. The performances of these algorithms are compared in terms of number of active nodes and average cover degree. Simulation experimental results show that this improved algorithm enhances the efficiency of redundant nodes determine more effectively and better adapts to the complexity of the network, while maintaining the initial coverage.
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Computer Engineering. 2011, 37(01): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2011.01.042This paper designs and realizes a cognitive radio network simulation platform by applying C# and SQL Server database technology. It realizes the cognitive user spectrum sharing among primary user, dynamic resource allocation by multi-modules cooperation and multi-PCs collaboration. The extend interface is preserved for user to implement algorithm, and the performance comparisons of algorithms can be obtained by the video window show. Result shows that the design provides development platform for practical application of cognitive radio network.
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Computer Engineering. 2011, 37(01): 125-127,130. https://doi.org/10.3969/j.issn.1000-3428.2011.01.043Aiming at the disadvantages of existed fair contract signing protocol based on short signature scheme without random oracles and q-strong Diffie-Hellman assumption, a new fair contract signing protocol with the off-line semi-Trusted Third Party(TTP) is proposed. The off-line semi-TTP intervenes into the protocol to assist to decrypt in case of trouble, at the end of the protocol run, the TTP does not obtain signatures from the participating party. Because this protocol is based on short signature, which needs low storage and little communication, it can be used in low-bandwidth communication and low-storage environments.
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Computer Engineering. 2011, 37(01): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2011.01.044As the question of the mathematical problems of FB, DLP and ECDLP cannot against quantum computer, the computational Diffie- Hellman assumption is extended on isogenies, and the computational Diffie-Hellman assumption based on isogenies between elliptic curves is proposed. Two key agreements on the computational Diffie-Hellman assumption are presented. And the agreements are proved secure in the random oracle.
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Computer Engineering. 2011, 37(01): 131-133,136. https://doi.org/10.3969/j.issn.1000-3428.2011.01.045The time risk model is proposed to identify the real damage degree of security vulnerability in information security risk evaluation reasonably and scientifically, combining with vulnerability lifecycle. The subsequent exploitation of the vulnerability is predicted by using Gompertz model based on the incident report data, and attack heat is calculated. Based on the attack heat and the attack technology development, the evaluation can be drawn on the time dimension. An example of Phf vulnerability is given to demonstrate the validity of this method, and the result indicates that it can reflect time risk truly and dynamically.
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Computer Engineering. 2011, 37(01): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2011.01.046Wireless transmission, broadcast of signals, resource-constraint, etc. bring some potential risks. This paper proposes a new mutual authentication protocol for RFID system. The protocol combines commendably public key encryption and symmetric cryptosystem for challenge-response based authentication. It can prevent many security problems including information leakage, replay attack, location tracing, spoofing attack, etc. The paper compares and analyzes the security and performance of the protocol, result shows that the protocol has more security for RFID system, it can be applied to RFID system.
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Computer Engineering. 2011, 37(01): 137-138,141. https://doi.org/10.3969/j.issn.1000-3428.2011.01.047This paper analyzes the security of a chaos-based stream cipher, it is found that the first several key stream bits of this chaotic cipher are not sensitive to the least significant bits of key, the parameter of chaotic mapping is not suitable as a key. Based on this information leaking, a divide-and-conquer attack is presented to decrease the entropy of key, and its effectiveness is confirmed by theoretic analysis and trials.
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Computer Engineering. 2011, 37(01): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2011.01.048Aiming at the uncertainty of trust management in the distributed environment, this paper introduces behavior aware analytical method into role based trust management for trust evaluation. The impact of behaviors on trust domain is quantized to trust value in a fixed interval. Role and domain reputation are calculated through statistics of cumulative behaviors of user groups, as feedback to adjust trust delegation between domains. The combination of static role and dynamic behavior will effectively enhance security in distributed networks.
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Computer Engineering. 2011, 37(01): 142-144,148. https://doi.org/10.3969/j.issn.1000-3428.2011.01.049ID-Based Cryptography(IBC) public-key system is lightweight, efficient, and of more convenient key management. But because of the lack of security protocols supporting, the application of IBC is limited. By designing IBC-based cipher-suite, an improved Transport Layer Security(TLS) protocol named IB_TLS is proposed in which RSA public-key is substituted by IBC public-key, and the number of message exchange is reduced. BAN logic is used to analyze IB_TLS formally, and the result shows that IB_TLS is secure.
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Computer Engineering. 2011, 37(01): 145-148. https://doi.org/10.3969/j.issn.1000-3428.2011.01.050Aiming at the problems of typical verification logic of security protocols, such as the limitations in verifying security properties, the lack of analysis ability of hybrid cryptography-based primitives. This paper proposes a new verification logic, which can verify almost all of the known security properties of the e-commerce protocols, such as authentication, secrecy of key, non-repudiation, accountability, fairness and atomicity. Because most of the verification logics are lack of formal semantics, and formal semantics can prove the correctness of the logic systems, the paper describes strand space semantics of the logic sentences in the new logic and proves the correctness of the main inference rules using strand space model.
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Computer Engineering. 2011, 37(01): 149-150,153. https://doi.org/10.3969/j.issn.1000-3428.2011.01.051To solve the great energy cost and poor efficiency of group key updating in Heterogeneous Wireless Sensor Network(HWSN), this paper proposes a group key management scheme based on topological information for HWSN. The scheme takes topological information of nodes to build an αβ key management tree. In the process of generating and updating, the group key management tree must be optimized to decrease energy cost and updating delay. Simulation experiments show that the scheme is an efficient and scalable group key management scheme which is suitable for heterogeneous Wireless Sensor Network(WSN).
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Computer Engineering. 2011, 37(01): 151-153. https://doi.org/10.3969/j.issn.1000-3428.2011.01.052Mobile IPv6(MIPv6) binding update is primary security question, IETF draft proposes a new binding update mechanism based on IKEv2/IPSec protocol. However, IKEv2 protocol is unsuitable for MIPv6 directly because of flaws. This paper improves IKEv2 protocol based on Weil pairing’s signature arithmetic, as well as the mechanism. The improved mechanism is verified in applied π calculus.
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Computer Engineering. 2011, 37(01): 154-155,158. https://doi.org/10.3969/j.issn.1000-3428.2011.01.053This paper considers permission and role’s attribute expressions as the important parts of authorization constraint. It gives the definition of constraint, and proposes some methods, procedures and algorithms for the identification, generation and optimization of attribute, attribute value, permission attribute expression, role attribute expression and user attribute expression by the introduction of role engineering. An example is given to show how these methods work.
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Computer Engineering. 2011, 37(01): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2011.01.054This paper proposes an architecture of program behavior analysis at ring 0 level based on virtual machine on Windows platform and a program behavior analysis system named Malbox is implemented, which is able to detect program’s process, file, registry and network behavior in a closed virtual environment. Experiments based on various malware samples prove that Malbox is efficient and performs well on detecting the host and network behavior of programs.
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Computer Engineering. 2011, 37(01): 159-160,163. https://doi.org/10.3969/j.issn.1000-3428.2011.01.055This paper proposes a method of protein structural prediction classes based on flexible neural tree. The approximate entropy and hydrophobicity pattern of a protein sequence are used to characterize the Pseudo-Amino Acid(PseAA) components. It extracts features of protein in data set. For a given protein sequence sample, a 27-D PseAA composition is generated as its descriptor. PseAA composition features as input data, the flexible neural tree is adopted as the prediction engine. A classification method named M-ary classifier is introduced. The 640 protein sequence is used as the dataset. Experimental result shows the method has better optimization of performance and improves the predictive accuracy rate.
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Computer Engineering. 2011, 37(01): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2011.01.056Aiming at the problems of low processing capability of rough sets to continuous domain attribute decision table and not easy to obtain relationship of fuzzy sets, a new method of continuous attribute reduction algorithms is proposed, based on combining fuzzy set with rough set. Continuous attribute values are transformed into fuzzy values with triangular membership function. And Hard C-Means(HCM) clustering is used to obtain relationship among the fuzzy sets and Genetic Algorithms(GA) is used to optimize the model. Simulation results show the effectiveness of the proposed model.
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Computer Engineering. 2011, 37(01): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2011.01.057To address the task schedule problem in grid resource management, an immunity schedule algorithm for grid task is put forward. The algorithm abides by the immune principles of clonal selection and affinity maturation, and seeks the all-around excellent result to the schedule problem for grid task. The settings of group generation and parameters of the algorithm are discussed, which can influence the performance of the algorithm. Experimental results of simulation demonstrate that the algorithm, compared with the conventional algorithm of grid task schedule, has the virtues of rapid task schedule, short-time resource allocation and steady function.
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Computer Engineering. 2011, 37(01): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2011.01.058For the choices of the Support Vector Machine(SVM) parameters mostly depending on experience is time-consuming, this paper proposes a method of selection based on GA, and a method of hybrid programming, based on the Component Object Model(COM) using Visual C # and Matlab. An example is introduced for the GA-SVM prediction modeling and procedures for implementation. Results show that optimizing the SVM parameters by the GA makes best use of it, meanwhile reducing the time for parameters selection greatly. The use of COM in integrated programming improves the development and operating efficiency.
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Computer Engineering. 2011, 37(01): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2011.01.059This paper converts the constrained optimization problem into unconstrained optimization problem using the penalty function, transforms the discrete vehicle routing problem into quasi-continuous optimization problem using the real number coding scheme, and uses an improved Particle Swarm Optimization(PSO) algorithm to solve the pitimum on the basis of the two methods. The improved PSO algorithm introduces hybrid PSO model and the mutation operator, and simulation results show this algorithm is more effective in maintaining the diversity of the particle population, improving the convergent speed and search accuracy, expanding the search range, avoiding converging at local maximum points and so on.
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Computer Engineering. 2011, 37(01): 173-174,177. https://doi.org/10.3969/j.issn.1000-3428.2011.01.060In order to solve the existed problems that are the population size required to be determined by the experience, weaker multi-peak search capability and longer training time for Castro clone selection algorithm. It proposes a new immune clone selection algorithm based on real coding and adaptive zoom mutation method, which is able to dynamically determine the population size, owns strong global and local search capabilities and can search the global optimal points and possibly the greatest number of local extreme points. Simulation results show the improved algorithm to find the average running time and average number of peak points is obviously better than Castro clone selection algorithm, multimodal function optimization results are significantly improved.
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Computer Engineering. 2011, 37(01): 175-177. https://doi.org/10.3969/j.issn.1000-3428.2011.01.061In view of the problems in current human identification based on Electrocardiography(ECG), such as small sample and multi-feature points detection, a novel approach using wavelet and Dynamic Time Warping(DTW) for human identification is investigated. The noise is reduced in preprocessing and the R peaks are detected by using wavelet transform. Then the reference templates of QRS wave and heart beat in limb leads are extracted and saved. Candidates are selected by the result of correction analysis between the test and templates of QRS waves. The only candidate is selected by the minimum distance between the test and templates of heart beat in limb leads using DTW. Experimental results show that the identification accuracy is 97.3% in 112 individuals and individual identification time is 4.4 s, and the proposed method solves the problems of human identification based on ECG under single feature point detection and large sample.
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Computer Engineering. 2011, 37(01): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2011.01.062This paper presents a new algorithm which integrates Particle Swarm Optimization(PSO) algorithm and Genetic Algorithm(GA) to solve the problem of resource allocation. According to the introduction of GA in the PSO algorithm, it effectively overcomes the inherent flaw of getting local optimal value by PSO algorithm and finds the global optimum value in the search space again. The method is simple, needs to set less parameters and speed up the convergence rate. Simulation results show the fusion algorithm achieves a better result in the aspect of grid resource allocation.
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Computer Engineering. 2011, 37(01): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2011.01.063Uniformly distributed constants-based decision tree evolved by Gene Expression Programming(GEP) is a kind of classifier with fairly high accuracy, but its performance on multi-attribute data classification is not satisfactory. This paper presents an algorithm of Differential Evolution (DE)-based decision tree algorithm by GEP. This new algorithm uses differential evolution method to improve the additional threshold, and makes the uniform constant array have both uniformly and diversity. Experiments on benchmark datasets show it performs better on multi-attribute classification problems than basic GEP decision tree.
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Computer Engineering. 2011, 37(01): 184-186. https://doi.org/10.3969/j.issn.1000-3428.2011.01.064Aiming at conventional smart car small visual range which affects path optimization, this paper proposes a control system of intelligent line-tracking vehicle with large vision based on servo driven sensor movement. It installs a servo driving motion sensor, increases the sensor range of the path identification. It uses a local path optimization, construction of a transitive relation, to create a mapping between sensor data and intelligent control of vehicle driving. Experimental results show that, installing a servo drive motion sensor and using a local path optimization, this control system increases path identification range, improves driving performance and the reliability of search lines, and increases the speed of transmission line.
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Computer Engineering. 2011, 37(01): 187-189,193. https://doi.org/10.3969/j.issn.1000-3428.2011.01.065Based on the FDR threshold filtering algorithm, a layered FDR threshold filtering algorithm is put forward. Through respectively making multiple hypotheses testing to the low frequency coefficients at the last level and the high frequency coefficients at other levels, multiple threshold values are obtained. The gained threshold values are taken as the criterion at the individual level. Simulation results for signals of heavysine, bumps, doppler, blocks show the proposed threshold algorithm is better than universal threshold, FDR and free distributed FDR threshold filtering algorithm in signal to noise ratio, relative error and so on. It has higher practical value.
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Computer Engineering. 2011, 37(01): 190-193. https://doi.org/10.3969/j.issn.1000-3428.2011.01.066For the problems in the process of making personal photo products with traditional manual based operations, such as complicated procedures, time-consuming and high loaded process of the network or servers, this paper proposes an individual image processing oriented immune algorithm, which utilizes some characteristic information such as a grade-based mutation and content image. This method establishes a series of evaluation criteria of photo productions, then confirms computations of distances between images and color intervals, continually, finds out the solutions of photo productions with the grade-based mutation, and realizes the rapid convergence and antibody targets selection. Theoretical analysis and simulations show that good feasibility and practicality of this algorithm can be obtained.
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Computer Engineering. 2011, 37(01): 194-196,200. https://doi.org/10.3969/j.issn.1000-3428.2011.01.067A multi-criteria ranking method about interval-valued intuitionistic fuzzy sets is introduced into the automatic negotiation model to weaken the subjectivity degree of preference information report from negotiation Agent and the interval intuitionist fuzzy sets of alternatives are obtained. Considering the incomplete certain information on weights, a nonlinear programming model is developed and the weight of various attribute is obtained. In order to overcome the precocious phenomenon on Genetic Algorithm(GA), the Niche Genetic Algorithm(NGA) is proposed to search optimization and improve astringency. Simulation test shows the model is feasible and effective, the precision is high and the value-stability is good, which can help negotiation Agent to reach fast a mutually beneficial agreement objectively.
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Computer Engineering. 2011, 37(01): 197-200. https://doi.org/10.3969/j.issn.1000-3428.2011.01.068Aiming at the task allocation problem of soccer robot system, this paper proposes a task allocation method based on utility function value. On the base of deep analysis task allocation of soccer robot system, the paper presents the definition of robotic utility function, and mainly discusses the concrete building process of utility functions for robotic players relative to different subtasks, task allocation algorithm of soccer robot system based on utility value is given. Simulation experimental results show that the method has less calculation amount, well real-time performance, and better task allocation effect than those methods mentioned in related references.
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Computer Engineering. 2011, 37(01): 201-203. https://doi.org/10.3969/j.issn.1000-3428.2011.01.069Considering image matching is a heavy computation task, this paper proposes a novel image correlation matching method based on Cloud Genetic Algorithm(CGA). To avoid mean image value increases the difficulty of image matching, an improved normalized correlation measure is developed as a fitness function for searching the best matching point. Since CGA can converge fast to a high quality local optimal, the novel method’s accuracy and speed are high, and it is robust to noise. Simulation results show that the proposed method can match both noise free images and noisy images with higher accuracy and higher speed than the adaptive genetic algorithm based matching approach.
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Computer Engineering. 2011, 37(01): 204-206. https://doi.org/10.3969/j.issn.1000-3428.2011.01.070Non-linear warping often appears in document images which is captured by the camera. In order to solve the problem, this paper uses image segmentation technology to detect words and text lines, applies linear fit to get lower baseline and upper baseline of the words, and makes the words rotation and vertical displace according to upper baseline and lower baseline, so that the corrected image can be obtained. Experimental results indicate that the method can rectify distorted images quickly and effectively, and elevate the probability of the rectified image identification in the optics character identification stage.
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Computer Engineering. 2011, 37(01): 207-209,212. https://doi.org/10.3969/j.issn.1000-3428.2011.01.071This paper proposes an image retrieval method based on binary color co-occurrence matrix named Binary Modified Color Co-occurrence Matrix(BMCCM). It uses “color invariant model of RGB quantity” to quantify the original image, calculates the color co-occurrence matrix of transformed image, gets the binarization of co-occurrence matrix, and uses Jaccard coefficient to measure the similarity between images to complete the image retrieval. Experimental results show that BMCCM is more accurate and efficient on retrieval than color histogram and color (auto) correlogram.
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Computer Engineering. 2011, 37(01): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2011.01.072According to the research of projection and structure features, a form document image recognition algorithm is proposed based on the projection and structure features of forms. The line feature of forms is obtained by projection, and the structure features are extracted by Hit/Miss transform. Due to the differences between the two features, it sets the threshold to distinguish form document images. Experimental results show that the proposed algorithm can distinguish between form and non-form document images accurately and efficiently.
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Computer Engineering. 2011, 37(01): 213-214,217. https://doi.org/10.3969/j.issn.1000-3428.2011.01.073Aiming at the deficiency of mixed noise removal algorithm for color images based on L&A-PCNN, this paper proposes an adaptive algorithm of mixed noise removal for color images based on improved L&A-PCNN. The adaptive setting method for key parameters and the estimation method of image pixels blurred by noises of L&A-PCNN model are gained with theoretical and experiments analysis. Experimental results show that the algorithm improves denoising performance of PSNR from 9% to 18% than L&A-PCNN algorithm, and gets a better visual effect when dealing with color images mixed noise removal, showing great adaptability and robustness.
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Computer Engineering. 2011, 37(01): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2011.01.074A new binary univariate nonlinear geometric approximating-type subdivision format is proposed in this paper. In this new format, instead of using linear combination of old vertices, one of new vertices is defined by displacement vector on normal vector direction . The normal vectors used in this format are computed adaptively in each iteration. Several parameters are used for the control of the subdivision process, and the influence of every parameter is local. It is shown that curves generated by this scheme can achieve convexity-preservation property, and the limit curve is smooth with wide range of free parameters.
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Computer Engineering. 2011, 37(01): 218-219,223. https://doi.org/10.3969/j.issn.1000-3428.2011.01.075To conquer structure information loss and mosaic effect at picture texture direction caused during the process of interpolation, a texture structure driven moving picture interpolation algorithm is proposed. It analyzes picture edges and texture information by performing Finite Radon Transform(FRAT), applies traditional interpolation methods to random texture areas, and designs different interpolation filter for areas with identified texture based on pixel position and texture direction derived before. Experimental results show that this strategy can increase image quality compared to usual ways.
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Computer Engineering. 2011, 37(01): 220-223. https://doi.org/10.3969/j.issn.1000-3428.2011.01.076When inpainting texture image, it may cause the boundary blur that copy the pixels or the texture chose out, which comes from neighbor of damaged image, into damaged image area along the isophate. In order to resolve the problem, an image is composed into a cartoon image and a texture image by Total Variation(TV). The cartoon image is inpainted based on the edges repaired. The texture image is inpainted by using texture synthesis guided by reconstructed boundary, so that the texture and structure of damaged image can be inpainted simultaneously. Experimental results show that the algorithm does well for the image with complex structure.
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Computer Engineering. 2011, 37(01): 224-225,228. https://doi.org/10.3969/j.issn.1000-3428.2011.01.077When normal unsharp mask method algorithm is applied to sharpening enhancement, the obvious noises are also enhanced. Based on this question, a method of image sharpening approach is proposed which is founded on the Thin Plate prior energy theory of Markov random field. The method can improve edge meanwhile it can’t enhance noise. The processing results of this method not only on the aspect of subjective visual effect but also on the aspect of objective evaluation are more satisfactory.
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Computer Engineering. 2011, 37(01): 226-228. https://doi.org/10.3969/j.issn.1000-3428.2011.01.078This paper proposes concepts of unitary projection histogram and unitary projection histogram moment invariant, and constructs a unitary projection histogram moment invariant for image feature extraction. Experimental results show that compared with the classic moment invariant theory, it can reveal structural information more effectively and distinguish subtle differences and similar images better. And it is robust when applied in image recognition.
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Computer Engineering. 2011, 37(01): 229-231. https://doi.org/10.3969/j.issn.1000-3428.2011.01.079Aiming at the complex logistics problems which result from the diversity and randomness of user needs in the production process, this paper presents a steel rolling logistics system modeling method based on Hierarchical Timed Colored Petri Net(HTCPN). By using top-down modeling approach, the Colored Petri Net(CPN) for the same devices with different color in the rolling system reduces the size of the system Petri net model and prevents space explosion. Experimental results show that the modeling method can reflect the characteristics of complex system and provide the basis for system optimization.
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Computer Engineering. 2011, 37(01): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2011.01.080This paper is based on NIOS II as the core of the System On a Programmable Chip(SOPC), designs the reconfigurable hardware configuration and control software core. It extends Trivial File Transfer Protocol(TFTP) server into a special transmitting and writing server to establish the method which may introduce multiple hardware configuration and software core on line, and builds a flow which may realize remote optional switch for hardware and software to achieve multi-strategy controller. Then, multi-strategy controller based on FPGA3C25 is realized. This design is verified in the control system for a large size telescope.
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Computer Engineering. 2011, 37(01): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2011.01.081A multi-rate decoder of Quasi-Cyclic LDPC(QC-LDPC) decoder is presented based on the improvement of layered decoding algorithm. The implementation has larger bit throughput resulting from fast convergence speed by more than 50 percent in terms of decoding iterations. Only four memories are used to store the messages which significantly reduce the area and the power dissipation. Adjusted integer quantization of layered decoding algorithm for check-node updating reduces the complexity and the correction factor guarantees the error rate performance. The proposed decoding architecture is implemented in the standard recommended. The decoder consumes 0.6 million gates, and reaches a throughput of 134 Mb/s at a clock frequency of 110 MHz with rate of 1/2.
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Computer Engineering. 2011, 37(01): 238-240,243. https://doi.org/10.3969/j.issn.1000-3428.2011.01.082This paper designs and realizes a rotating machine faults diagnosis expert system based on Case Based Reasoning(CBR) and Rule Based Reasoning(RBR). It goes on reasoning by combining CBR and RBR serial manner. CBR is a priority to search diagnosis result by matching cases. It turns to the general RBR to get the result when failed, and gives feedback to the repository to optimize it. Application results show that the Diagnosis results of this system conforms with situation, and it is faster and has more pertinence.
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Computer Engineering. 2011, 37(01): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2011.01.083By studying determination method for optimal assembly sequence, and using assembly part lists and optimal assembly sequence as input of the assembly process design system, this paper realizes the detailed assembly process design through mapping from the assembly function tree to assembly process mechanism tree. A method that describes assembly case through functional requirement, behavioral model and process mechanism model is proposed, and process similarity factor is presented to select the most similar case. An application example is provided to prove the effectiveness of the method.
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Computer Engineering. 2011, 37(01): 244-245,248. https://doi.org/10.3969/j.issn.1000-3428.2011.01.084Aiming at the problems of real-time data detection and the variety of control signals the signal diversification of industrial equipment, this paper designs a wireless measurement and control terminal based on Advanced RISC Machine(ARM) and image simulation. It simplifies hardware structure by using piece inside and outside resources of ARM chip, achieves a custom communication protocol by transplanting μC/OS-Ⅱ and UCGUI. It uses the method of image simulation for the running equipment to run with the state of virtual construction and dynamic display. Application results show that the wireless terminal can strengthen the ability of data collection and the capacity of industrial analysis and process, and improve the efficiency of the monitoring staff.
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Computer Engineering. 2011, 37(01): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2011.01.085Aiming at the characteristics of high-speed real-time processing and wide mass storage of SAR imaging algorithm, this paper designs and implements a high-performance signal processing module based on multi PowerPC processor. This processing module constructs variety levels of networks by using a variety of high-speed serial buses to adapt to the transmission of different types of dataflow in signal processing system. It completes the mapping of SAR imaging algorithm on the module by combining with bottom signal processing nodes of mixed parallel structure. Application result shows that the signal processing system architecture based on this module is standardized, modular, reconfigurable and scalable.
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Computer Engineering. 2011, 37(01): 249-250,253. https://doi.org/10.3969/j.issn.1000-3428.2011.01.086
With embedded Linux and network technology, a field video monitoring server, which consisted of Zc0301 camera and S3c2440 platform, is designed to cope with problems of high-cost, low extensibility, lack of practicalness. Local network test indicates that the video server’s network package data transmission speed is 1.858 Mb/s, video frequency transmission frame speed can reach 20 f/s and can meet needs of remote video surveillance.
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Computer Engineering. 2011, 37(01): 251-253. https://doi.org/10.3969/j.issn.1000-3428.2011.01.087This paper implements a design of time-sequence control system based on PC104 by using below PC104 embedded controller in combination with an upper industrial computer. In the design, PC104 controller works black-box mode to finish the time-sequence task which has higher real-time demand. Ethernet communication is applied between the upper computer and the PC104 controller, and remote monitor is achieved by the upper computer. Application results show that this system has the features of high reliability, high real-time, flexible configuration and strong function restructure, and it can provide reliable time-sequence control for sub-system.
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Computer Engineering. 2011, 37(01): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2011.01.088Based on the graphic display characteristics in virtual environment, the paper sets up a virtual display performance evaluating system in paravirtualized environment and acquires the related performance parameter by tracing. It makes a theoretical analysis of the factors influencing the display capability by queue-modeling and brings out the performance bottlenecks in different situations by making a comparison with the actual experimental data.
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Computer Engineering. 2011, 37(01): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2011.01.089In order to improve the ability of deaf semantic analysis, the multi-channel band-pass filtering skin-hearing aid based on Digital Signal Processing(DSP) is designed. By comparing today’s hearing-aid device and latest idea of skin-hearing, it reveals that the advantages of skin-hearing rely on no residual hearing and it can solve the deaf hearing problem from the fundamental. At the same time, the voice recognition of skin-hearing is a pattern matching process. This paper focuses on the two aspects of hardware and software to present the research program. The innovation lies with using multi-channel band-pass filter technologies in traditional method of skin-hearing, and improves the capacity of voice-recognition.
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Computer Engineering. 2011, 37(01): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2011.01.090Based on the ISO/IEC 18000-6C UHF Radio Frequency Identification(RFID) standard, this paper proposes a Slot-based Partial Competitive(SPC) anti-collision algorithm, which introduces dynamic binary tree search technology into the competitive collision avoidance mechanism for the first time. Moreover, the SPC algorithm applies the specific technologies to idle slots and collision slots. The performances of the dynamic binary tree search, ISO/IEC 18000-6C and the SPC algorithm are compared via NS-2 simulation experiments. Simulation results indicate that the SPC algorithm is able to not only reduce the recognition time by 30% and 20% compared with the binary tree search algorithm and the 18000-6C algorithm, respectively, but also improve the recognition rate by 35% compared with 18000-6C algorithm.
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Computer Engineering. 2011, 37(01): 263-264,267. https://doi.org/10.3969/j.issn.1000-3428.2011.01.091For the complexity under the environment of high-speed train operation, a comprehensive evaluation model of comfort for high-speed railway is put forward. Based on the fusion method of rough sets and fuzzy analysis, the comfort index of high-speed trains is reduced and extracted, a evaluation index system and the evaluation matrix are established. The comfort on Beijing-Tianjin intercity high-speed railway is comprehensively evaluated. Result shows that the model has a certain practicality and advantages.
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Computer Engineering. 2011, 37(01): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2011.01.092This paper presents a real-time task schedule algorithm based on dual priority for the homogeneous multi-processor system. Aiming at the character of sporadic tasks, the algorithm pretests the sporadic tasks and further improves the success rate of sporadic tasks schedule. The simulation results show that when the multi-core processor system utilization is at the limit, the algorithm is still able to schedule the hard real-time periodic tasks successfully and ensure the high success schedule rate of soft real-time periodic tasks and sporadic tasks.
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Computer Engineering. 2011, 37(01): 268-269,272. https://doi.org/10.3969/j.issn.1000-3428.2011.01.093This paper proposes an algorithm on clock jitter measurement in optical communication based on Data Transition Tracking Loop (DTTL). On the basis of jitter test model, equivalent base-band phase model is given, and a formula about amplitude of jitter error is deduced. The formula shows relationship between jitter error and gain of loop filter, jitter amplitude, jitter frequency. Fixed-point simulation by FPGA shows that the same error amplitude in jitter test can be obtained for the theory and the simulation. For optical communications, the algorithm has the advantages of simple and precise method.
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Computer Engineering. 2011, 37(01): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2011.01.094针对村镇管理部门、企业和农户缺乏及时准确产业信息的问题，以提供村镇产业信息服务为目标，探讨Web信息抽取、网络地理信息系统WebGIS、富客户端技术在村镇产业服务信息系统建设中的应用。研究基于XML的产业市场信息Web抽取、基于富客户端的产业专题地图的动态制作和发布，在实际系统中成功运用，为村镇产业布局、产品市场交易提供有效的信息技术支撑。
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Computer Engineering. 2011, 37(01): 273-275,279. https://doi.org/10.3969/j.issn.1000-3428.2011.01.095After analyzing the abstract logic font, device font and Chinese character set interface and font interface calling flow, it is found that the open source MiniGUI is lack of the font more than 16×16 size. For this shortcoming, the UCDOS Chinese font interface is realized and combined with the MiniGUI seamlessly. Thus, the MiniGUI can use any font in the UCDOS and support the big font and many font styles. This interface can be widely applied in embedded GUI interface design and development based on MiniGUI.
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Computer Engineering. 2011, 37(01): 276-279. https://doi.org/10.3969/j.issn.1000-3428.2011.01.096On the basis of an analysis in the MUX-PDU extracting algorithm based on only BP neural network and its limitations, according to the posterior information of MUX-PDU under mobile level-2 in H.223 protocol, a united MUX-PDU extracting algorithm based on BP neural network and posterior information is proposed. This algorithm is able to adjust the decision threshold of MUX-PDU identifier dynamically, and making corrections to the extracted MUX-PDU frames by using posterior information is capable. Simulation result shows that this algorithm is able to decrease the packet loss rate efficiently, which provides a reliable guarantee for video calls in the 3G communication.
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Computer Engineering. 2011, 37(01): 280-281,284. https://doi.org/10.3969/j.issn.1000-3428.2011.01.097DS-CDMA system can not only support voice and data service, but also support multi-service. Because the requirement of power and BLock Error Rate(BLER) is different for different services, Outer Loop Power Control(OLPC) strategies must take measures to support different services. This paper introduces the ever existed problems about DS-CDMA OLPC for multi-service and analyzes the power control theoretical model. The improved OLPC brings its own target SIR adjustment command as the single service OLPC. The OLPC algorithm is improved and the performance comparisons between the old algorithm and the improved algorithm are given. Experimental results show the good performance of the improved OLPC algorithm and prove the validity for multi-service.
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Computer Engineering. 2011, 37(01): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2011.01.098In order to achieve synchronous acquisition of large-scale signals and parallel computing in high-resolution three-dimensional acoustic imaging system, a parallel computing system based on Field Programmable Gate Arrays(FPGA) is presented. The system uses Spartan-3 to synchronize 2 304-channel sensors at a unique clock. The sampled data are downsampled using discrete fourier transform to reduce data volume. The weights of the sensor array are optimized by Virtex-5 to decrease the calculation complexity. Step-beam forming algorithm is adopted to reduce the memory requirement. It realizes real-time three-dimensional image displaying on PC. Experimental result certifies the feasibility of this system.
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Computer Engineering. 2011, 37(01): 285-286,289. https://doi.org/10.3969/j.issn.1000-3428.2011.01.099Omnidirectional image unwrapping algorithms are complex in calculation, so they are non-real time on present main processor. The direct parallelization effect is not satisfactory. To solve the problem, this paper improves omnidirectional image unwrapping algorithm based on the quadratic interpolation, realizes parallel processing on multiple-core processor, and analyzes the unwrapping time, parallel performance and rendering speed with the unwrapping experiment in different resolution. Experimental results indicate that it improves the real-time resolution 640×480 of the image unwrapping to 1 024×768 on Core 2 Duo E7200 2.53 GHz processor.
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Computer Engineering. 2011, 37(01): 287-289. https://doi.org/10.3969/j.issn.1000-3428.2011.01.100This paper presents a novel representation of the global cortical folding pattern based on the shape patterns of sulcal fundi. 14 major sulcal fundis are extracted semi-automatically. By using Affinity Propagation(AP) algorithm, each individual sulcal fundi is clustered into subgroups as the elementary patterns. A higher level of global folding pattern is represented by taking 14 sulcal fundis as a whole for AP clustering, and the global folding patterns are classified accordingly. The proposed folding pattern representation method has been applied to group cortical surfaces with 281 normal samples into sub-populations, and interesting results are obtained.
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Computer Engineering. 2011, 37(01): 290-292. https://doi.org/10.3969/j.issn.1000-3428.2011.01.101It is important and difficult to schedule the resources promptly and effectively in various emergency management systems. Network expansion model and Arc Engine technologies are introduced. Emergency resources allocation method at multiple rescue points is provided according to their character and based on the goal of earliest emergency start time and least rescue time points. Optimal and visual emergency resources allocation system based on GIS is designed and accomplished.
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