20 April 2011, Volume 37 Issue 8
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Computer Engineering. 2011, 37(8): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2011.08.001The visual modeling technology can reduce the difficulty of the design of parallel programs effectively, the complex hardware architecture still puts forward new challenges on the parallel program design method on the software level. To solve these issues, this paper proposes a visual modeling methodology based on the hierarchical idea and an hierarchical modeling scheme for parallel programs, and designs and implements a modeling system called e-ParaModel for multi-core cluster environments. A modeling paradigm to verify the system’s feasibility and applicability is completed.
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Computer Engineering. 2011, 37(8): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2011.08.002Generalized signcryption not only fulfills both the functions of signature and encryption, but also provides confidentiality or authenticity separately under specific inputs. This paper presents an identity-based generalized signcryption scheme based on bilinear pairing, in which three modes are realized through changing input’s identities, i.e. signcryption mode, signature-only mode and encryption-only mode. The proposed scheme has improved the drawbacks of receiver verifying signature after decrypting in the traditional signcryption shceme. Anyone can identify the source of the ciphertext without the plaintext. The scheme is safe and also efficient regarding the computation costs after analyzing other schemes.
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Computer Engineering. 2011, 37(8): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2011.08.003By studying the three-dimensional analysis of the shortest distance as well as Marching Cubes(MC), this paper proposes an algorithm about the shortest distance isosurface extraction based on three-dimensional grid model, i.e. by importing cost data and source data, it can be realized automatically to output the shortest distance isosurface of any valid value from the source. This method allows inputting multiple source data, and can be applied to non-homogeneous three-dimensional space. Experimental test result shows that the algorithm design is reasonable and feasible.
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Computer Engineering. 2011, 37(8): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2011.08.004Based on a combination of elliptic curve cryptography Combined Public Key(CPK) technology and using self-certification approach identifies ,the paper proposes a new authentication protocol, which applies to Wireless Mesh Networks(WMNs) roaming scenarios and supports large scale application. Analysis results show that this protocol completes mutual authentication and establishes a shared key with fewer interact times, and it proves Universally Composable security(UC).
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Computer Engineering. 2011, 37(8): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2011.08.005The imaging mechanisms for optical and SAR imagery is different, which throws a big difficulty in the registration between them. Aiming at above problem, this paper proposes an registration method based on virtual searching window. Based on spatial features of registered imagery, the virtual searching window is constructed, and then the spatial features and gray statistical features are combined together to register optical and SAR imagery. While the algorithm’s searching efficiency is guaranteed, its precision is improved. Images of Radarsat-2 and ASTER with big differences in scale and angle are tested. Some features are extracted manually to check the transform model’s precision, the results indicate that errors are lower than one pixel, which effectively proves that the algorithm is robust to differences in scale and angle between optical and SAR imagery and has a high precision.
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Computer Engineering. 2011, 37(8): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2011.08.006A fast and stable algorithm of Boolean operation of complex geological body is proposed. The algorithm does not require tracking intersecting lines, uses the intersecting edges with the topology information to classify the regions of bodies, avoids the judgment of the triangles inside the bodies, and improves the speed of operation. At the same time, before Boolean operations the algorithm resolves the conflict caused by the numerical calculation errors between the relevant categories, and ensures the stability of operation. This method is applied to LionKingSoft digital mining platforms system and the bodies of data-dispersive, data-intensive and with holes, especially the massive, exotic three-dimensional complex geological bodies.
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Computer Engineering. 2011, 37(8): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2011.08.007To keep the sensitive file away from the thread of stealing and leakage, this paper designs and implements a stealing and leakage monitor system based on Ring0 privileged code. The system can monitor and protect confidential files promptly by using the components of file searching and unordinary action monitoring. The system’s performance is satisfying in practice.
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Computer Engineering. 2011, 37(8): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2011.08.008
In order to enhance reliability of X processor and save its power and chip pad, this paper designs a general Serial Peripheral Interface(SPI) Flash controller, which takes SPI Flash as program-loading memory. The component structure and realization method are given. Assert checks of Property Specification Language(PSL) are used to verify functions of the controller to decrease verification complexity and enhance verification quality and speed. Experimental result shows that function coverage of the controller obtains 100%.
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Computer Engineering. 2011, 37(8): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2011.08.009This paper analyzes the existing association rules updating algorithm Incremental Updating Algorithm(IUA), finds out that when the decision makers give priority attention to the situation of maximum frequent itemsets, this algorithm can not lower the cost of the database traversal to quickly access to the largest number of frequent itemsets. For the lack of the algorithm, an algorithm which is based on reverse search approach to update association rules is presented. The updating algorithm based on reverse search generates all frequent itemsets of new itemsets. It splices the new largest frequent itemsets and original largest frequent itemsets for trimming, gets the updating maximal frequent itemsets. The algorithm not only reduces the traversal times in the process of association rules updating, but also realizes the priority access to the largest operation of frequent itemsets.
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Computer Engineering. 2011, 37(8): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2011.08.010
In the context of semantic Web, knowledge bases sometimes are single and dispersed. As a result, it hampers the development of semantic Web. A method of integration of multiple knowledge bases based on minimal concept sets is proposed. The minimal concept sets are defined. The method of generating minimal concept sets is given and mapping’s strategies in ontology mapping model based on risk minimization are improved and integration algorithm of multiple knowledge bases on basis of minimal concept set is designed. The complexity of the algorithm is proved by an application example.
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Computer Engineering. 2011, 37(8): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2011.08.011In association rule mining algorithm of data mining, conventional frequent pattern mining algorithms need the user to specify minimum support of itemsets. By using the Top-k pattern mining concept, some algorithms are improved to need no minimum support. However, threshold k need be specified. Based on all above, a new algorithm is proposed, which is called TNFP-growth. The algorithm need not specify minimum support or thresholds, and mines patterns with the descending order of their support values and returns frequent patterns to users sequentially. Experimental result proves that it has a high executing efficiency and good scalability.
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Computer Engineering. 2011, 37(8): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2011.08.012Traceability link recovery among software process products is very important in many fields, such as software maintenance, as well as requirement trac. Based on Latent Semantic Indexing(LSI), the traceability recovery information can be extracted automatically from program source code and the related Chinese documentation. The obvious advantage is that the presented method does not rely on the pre-defined thesaurus and knowledge for the code and documentation, and to some extent, it improves the recall and precision.
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Computer Engineering. 2011, 37(8): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2011.08.013This paper proposes a high-performance memory system with the standard server and protocol——Union System, to address the issue of grid file access. It adopts the data management method which is used in the cluster environment and enables the access of multi-sites through multi-standard data servers. The technologies applied include Grid FTP and OGSA Byte I/O interface, etc. It turns out that the Union System can be used as a parallel file system in the real grid environment and can achieve the excellent result of data access.
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Computer Engineering. 2011, 37(8): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2011.08.014In order to solve the memory requirement of large-scale symmetric equations, a new kind of parallel Gaussian elimination method which is based on the symmetric equations is put forward. Analysis shows that the sub-square is symmetry in the process of Gaussian elimination. In order to reduce the space application and improve the efficiency of parallel program, the parallel program can only read and calculate triangle section of linear equations. After test, its efficiency is better than traditional algorithm. This method can be widely applied to large-scale symmetric equations in the numerical calculations.
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Computer Engineering. 2011, 37(8): 43-46. https://doi.org/10.3969/j.issn.1000-3428.2011.08.015Corresponding to the lack in abilities of storage and query, a relation scheme, which owns the identical representation with CIM logical model, is defined. Those constraints in logical model, which take the form of logical sentences, are transformed into constraints on the cardinal of some related logical relations. With respects to the model access, the DAF interface, which is the basic CIS interface of IEC61970, is realized by relation algebra as an example. Research results show that the efficiencies of query and availability of constraint verification can be acquired by a well choosing relation scheme, while the rich representative ability of logical model is still reserved.
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Computer Engineering. 2011, 37(8): 47-49. https://doi.org/10.3969/j.issn.1000-3428.2011.08.016This paper proposes a high-performance algorithm for text classification based on normalized vector and matrix projection. The main idea of this algorithm is that the three-dimensional feature space of training samples is projected onto the two-dimensional feature space, and the normalized feature vector is obtained. When matrix projection is operated, the calculation of feature weight concerns not only document frequency from a single category but also term frequency from a single category, achieving the aim of decreasing dimension of features and improving classification efficiency and accuracy. Compared with the kNN algorithm, the result shows that the proposed algorithm greatly improves performance and accuracy of text classification.
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Computer Engineering. 2011, 37(8): 50-51. https://doi.org/10.3969/j.issn.1000-3428.2011.08.017In view of the low efficiency about testing smart CPU card application software, this paper proposes a kind of embedded method based on Tcl scripting language. In the Personal Computer/Smart Card communication protocol(PC/SC) system, the test system is embedded in Tcl codes, and designs Tcl extended commands to test the soft function. Each function is tested by different test cases, through the test system interface to call the corresponding test script (extension named .Tcl). It improves the efficiency of regression test in the automation process of embedded high-capacity CPU card.
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Computer Engineering. 2011, 37(8): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2011.08.018The keywords used in information retrieval and text messages in junk SMS retrieval do not match, so it affects information retrieval. This paper proposes a new method of query expansion words on the basic of context and global information. At the same time, the expansion words are selected according to their relation with the whole query. Additionally, the position information between words is considered. The paper selects 3 000 text messages to be tested, results show that the method improves the average precision.
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Computer Engineering. 2011, 37(8): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2011.08.019In order to solve the high-dimensional problem in similarity search over time series data, a new method of indexing and similarity searching in time series databases based on (DWHT)W is proposed in this paper. (DWHT)W is orthogonal and can use fast algorithm, and its transformation matrix is very simple. (DWHT)W has excellent performance in feature extraction and is used as an efficient dimensionality reduction technique to permit similarity search over large time series databases without false dismissals. Experimental results demonstrate that performance of the proposed method is more efficient than that of DFT(Discrete Fourier Transform) and DWT(Discrete Wavelet Transform).
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Computer Engineering. 2011, 37(8): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2011.08.020In spatial data warehouse, the aggregation results of spatial measures in materialized view require substantial storage space. Parts of spatial measures are selected to materialize. And the existing materialized view selection algorithms are mostly designed for view selection. They can not be applied for handling spatial measures. This paper proposes a spatial measures materialized selection algorithm based on cluster method for spatial region merging operation. All merged groups of spatial object are clustered. In each cluster, the algorithm calculates benefit for every merged group. After the best merged group based on the benefit calculation is selected to materialize, the algorithm only recalculates the benefits of merged groups in the cluster which includes materialized group. Overhead of benefit calculation is greatly reduced. Experimental results show the superiority of the algorithm.
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Computer Engineering. 2011, 37(8): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2011.08.021Aiming at the reliability evaluation method of complex structure network, a method combining with reliability-preserving reduction is proposed. In order to reduce the complex, the method uses preserving reductions to predigest the original network, gets the relation between new and original network reliability according reduction step, via Monte-Carlo(MC) method to finish the evaluation. The precision of evaluation under reliability-preserving reduction is also discussed theoretically. Validity simulation of the reliability evaluation method is presented.
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Computer Engineering. 2011, 37(8): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2011.08.022This paper introduces classical minimum interference routing algorithm MIRA and WSC, they locate link weight only by considering a single network maximum flow. Therefore, a new minimum interference routing algorithm named MWSC is presented. MWSC algorithm takes muti-network maximum flow into account. It can locate link weight more accurate. Simulation result shows that MWSC has lower request rejection rate than MIRA and WSC.
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Computer Engineering. 2011, 37(8): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2011.08.023In order to solve the problem that the operation of genetic algorithm needs lots of times when applied to Quality of Service(QoS) multicast routing, a method of parallel genetic algorithm based on cluster route is proposed, and the cluster router architecture is improved to make it applicable for the operation of parallel genetic algorithm. This algorithm improves the initial population, makes the every slave router initializes the population individually, reduces the number of the communication between master and slave routers and shortens the time of the convergence. Experimental results prove the validity of the algorithm.
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Computer Engineering. 2011, 37(8): 70-73. https://doi.org/10.3969/j.issn.1000-3428.2011.08.024Due to the problem of Distributed Hash Table(DHT), which is that the logical topology does not match the actual network topology, it results in the problem of excessive delay of lookup operation. Aiming at this problem, this paper proposes a DHT optimization method based on node exchange to solve this problem by adjusting the logical location of DHT node, and ultimately to improve the search performance of DHT. The nodes are classified by using the landmark method, the nodes whose physical location close to each other belongs to the same landmark district. It uses the idea of geographic layout, makes the DHT overlay network logical topology match the underlying physical topology as much as possible, and thus reduces the DHT query delay, which improves the performance of DHT routing.
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Computer Engineering. 2011, 37(8): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2011.08.025According to the requirement of network management in Forwarding and Control Element Separation(ForCES) framework mentioned by RFC 3654, this paper proposes a method for supporting SNMP in ForCES by improving the mechanism of maintaining large dynamic MIB tables of ForCES Network Element(NE). Experimental result shows that compared with traditional method, the method proposed needs less response time and gets better performance.
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Computer Engineering. 2011, 37(8): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2011.08.026In order to further improve the QoS over real-time voice and video data transmission, by considering the basic principle of Multi-Protocol Lambda Switching(MPLmS) network and analyzing label distribution strategy, this paper proposes an improved feedback Round Robin(RR) schedule algorithm. It prioritizes the priority of the high-priority packet schedule, and prevents the lower priority group from discarded because of failing to be scheduled in a long time. Experimental results show that the algorithm can distribute the link bandwidth effectively to ensure good performance of time delay.
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Computer Engineering. 2011, 37(8): 80-81. https://doi.org/10.3969/j.issn.1000-3428.2011.08.027This paper analyzes the security issue in Home Agent(HA) switching procedure, explaining a re-authentication solution based on diameter protocol. Before the mobile node switches to a new HA, the server distributes the re-authentication key to the mobile node and the new HA. After it, they use the re-authentication key for authentication. This paper also proves the security of IKEv2 pre-shared key distribution using BAN logic, and analyzes the performance of this solution. According to the analysis, the performance of this solution is better than other related solution.
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Computer Engineering. 2011, 37(8): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2011.08.028This paper proposes an improved Particle Swarm Optimization(PSO) method based on probability of measurement model. It is target at the effective coverage of the network to carry out coverage control. The sensor coverage radius and discrete grid points of the coverage performance are analyzed. The effective coverage of improved PSO method reached 88.22% by simulating, and it indicates that the method is effective.
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Computer Engineering. 2011, 37(8): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2011.08.029
Based on the characteristics analysis of Anti-Radio Missile(ARM) echo wave, three parameters Chirplet Transform(CT) is proposed, choosing three parameters of five in CT. A new method of ARM detection technique is also proposed associated with adaptive linear prediction filtering algorithm. Implemented by FFT, it can narrow the searching range and reduce the requirement of input SNR effectively. Simulation results show that ARM can be detected fast and precisely in this way, in the surrounding of low SNR and high aircraft echo interference, so that a reliable early warning of ARM launching can be given.
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Computer Engineering. 2011, 37(8): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2011.08.030Based on the idea that different kinds of switches have different kinds of performance, this paper proposes a kind of Heterogeneous Parallel Switch Architecture(HPSA). Three kinds of traffic classes are supported, which are Guaranteed Bandwidth(GB) traffic, Guaranteed Delay(GD) traffic, and Guaranteed Lost(GL) traffic. The Quality of Service(QoS) of each traffic class is realized by switching different traffic classes using different kinds of central planes. Simulation results show the GB traffic bandwidth, GD traffic delay performance, and GL traffic lost rate of HPSA are all better than that of iSLIP IQ and basic PPS.
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Computer Engineering. 2011, 37(8): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2011.08.031
This paper presents a Quasi-Birth-and-Death(QBD) model for damaged nodes in Ad hoc network. Since the communication in Ad hoc network is distributed, the destruction of nodes in the route between transmitter and receiver will break off the communication. Too many damaged nodes will result in some nodes unreachable. By assuming damaged vehicles’ arrival be subject to Poisson process, repair time and vacation time be exponentially distributed, it creats QBD model for Ad hoc network nodes damage and fix process, uses matrix analysis method to get stationary distribution, and then obtains damage nodes average queue length, the probability of no need to wait and so on. It is helpful on saving resources while keeping the network stability, can be a reference when make maintenance strategy.
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Computer Engineering. 2011, 37(8): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2011.08.032The electromagnetic wave will interfere with each other in the process of transmission in wireless network communications. Physical-layer Network Coding(PNC) reduces the communication interaction between nodes through a proper modulation-and-demodulation technique. PSK is a common physical layer modulation technique, but PSK has phase ambiguity and continuous “0” continuous “1” problem, and cause receive error. A scheme differential phase-shift keying based on PNC-DPSK is proposed, and it is also extended to M-ary differential phase-shift keying. The novel scheme is a solution method to PSK’s phase ambiguity and continuous “0” continuous “1” problem, and it also can reduce about 50% energy consumption in the relay node.
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Computer Engineering. 2011, 37(8): 97-98. https://doi.org/10.3969/j.issn.1000-3428.2011.08.033
In the Wireless Sensor Network(WSN) where nodes are randomly deployed, the proposed sensor scheduling schemes can not guarantee uniformly distributed and energy balanced at the same time. Aiming at this problem, a distributed Energy-Balanced Location-independent Coverage Protocol(EBLCP) is proposed. Based on virtual coordinate, EBLCP creates temp-sets in which working nodes are elected by residual energy of some neighboring nodes and its own. To compare with NSVC and DELIC, the simulation and analysis study demonstrate that the EBLCP not only provides high rate of area coverage, but also prolongs network lifetime to a large extent.
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Computer Engineering. 2011, 37(8): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2011.08.034
When handover bursts out, the generation of Care-of Address(CoA) of mobile routers, especially nested ones, and the duplicate address detection followed are the most time-consuming parts compared with the other processes. In this paper, after reviewing the existing schemes in the eye of delay related to CoA, it is based on access router tree model and Hash function, gives a novel scheme of CoA configuration and corresponding handover algorithm, to reduce the time cost and the signal overhead. Performance evaluation indicates that, compared with the existing solutions, lower delay can be achieved in CoA configuration of nested mobile routers and also in handover.
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Computer Engineering. 2011, 37(8): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2011.08.035
By analyzing the fundamental working tenet concerning the flow control agreement of the Fibre Channel(FC), this paper proposes an OPNET-based simulation model for controlling the flow of FC. The design program models the process nodes of sending and receiving. Simulation results show that the model proposed can abide by the flow control agreement of FC precisely with the advantages of simplicity, straghtforwardness and extensibility under the environment of OPNET and using C programming language as the development tool.
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Computer Engineering. 2011, 37(8): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2011.08.036In this work, a software watermarking algorithm through hiding watermarks in scene graph data structures using in Java3D applications is presented. According to a secret initial order of scene graph traversal, a secret message is embedded through circular-left shift operation and a numbering system. The embedding and extracting technology are discussed. The method does not change the size of scene graph, and the embedded watermarks are more robust than other watermark algorithms.
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Computer Engineering. 2011, 37(8): 108-111. https://doi.org/10.3969/j.issn.1000-3428.2011.08.037A new efficient certificateless compact sequential multi-signature scheme is proposed based on the certificateless public key cryptosystem and bilinear pairing technology. The scheme is compact, the length of signature is fixed, and does not grow with the number of the singer. Meanwhile, the scheme is efficient. In the scheme, the numbers of bilinear pairing is also fixed, and the computation complicacy of signature algorithm or verify algorithm is independent with the singer’s number. Furthermore, basing the random oracle, the scheme proves secure against existential forgery under the adaptive chosen message attacks, assuming that the computation Diffie-Hellman problem assumption holds.
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Computer Engineering. 2011, 37(8): 112-114. https://doi.org/10.3969/j.issn.1000-3428.2011.08.038Three-party Password-Based Key Exchange(PBKE) protocols are extended from two-PBKE protocols for three-party environments. Most existing three-PBKE protocols are designed for the user-user-server architecture, in which each user shares his password with a trusted server. Kim and Choi reveales many three-PBKE protocols’ weakness in resisting undetectable on-line password guessing attack, and proposes an enhanced protocol to resist the described attack. However, it is inefficient and needs three rounds interaction between the two users. This paper presents an efficient construction for three-PBKE, and proves its security in AIP model.
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Computer Engineering. 2011, 37(8): 115-117. https://doi.org/10.3969/j.issn.1000-3428.2011.08.039The special characteristic of Wireless Sensor Network(WSN) asks the key establishment scheme for WSN to be secure and effective. According to the past research, the key-pool based key establishment scheme is fit for WSN. However, the secure link connectivity of WSN is not so good. The symmetric pair-wise key establishment scheme based on the bivariate polynomial can get a high secure connective link rate, but it does not secure enough. Based on the two schemes, a new key establishment scheme is presented. Analysis and simulation results show that this new pair-wise key establishment scheme makes much more improvement than the classical pair-wise key establishment scheme on the security, the connectivity, the scalability, the effectiveness and so on.
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Computer Engineering. 2011, 37(8): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2011.08.040As Wireless Sensor Network(WSN) deployed in the natural environment, the network faces many security problems and the trust relation between nodes is difficult to confirm. Aiming at the problem, a fuzzy trust model is established to deal with the trust evaluation and calculation problems between nodes by adopting fuzzy theory, and this fuzzy trust model is used to solve routing security issues for WSN. Experimental results show that the trust model can evaluate the trust status of the node effectively and resist packet loss of misbehavior nodes.
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Computer Engineering. 2011, 37(8): 121-123. https://doi.org/10.3969/j.issn.1000-3428.2011.08.041Aiming at the shortcoming of traditional anti-Trojan technologies, this paper presents the Trojan horse detection method based on nonlinear Support Vector Machine(SVM) model. This method establishes system call sequences in accordance with its system calls function in the system, and converts into SVM readable tags, and places in the data warehouse for SVM extracted as the feature vectors. And to determine the abnormal behavior of testing procedures to determine whether it is Trojan horse by classifying the detected program behaviors based on the SVM classifier. Experimental results show that this method has high accuracy rate, and takes up very little system resource. Besides, it also has a very good performance in detection time and detection of known and unknown Trojan horse attacks.
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Computer Engineering. 2011, 37(8): 124-126. https://doi.org/10.3969/j.issn.1000-3428.2011.08.042Existing evaluation methods do not consider the time decay of behavior history records, and there are some small number of malicious users with less frequency, low-value access for higher confidence. In order to resolves trust issues decay over time, this paper proposes a grid entity behavior evaluation method based on sliding window by constructing a time correction function. This method can make the calculation of trust degree more accurate, timely and objectively reflect the real behavior of entity, and it provides the correct basis for the system in making decision about follow-up behaviors of the entity.
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Computer Engineering. 2011, 37(8): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2011.08.043It is difficult to detect the intention of an intruder, identify semantics of attacks and predict further attacks effectively using intrusion detection methods in the construction of high-level attack scenario and disposal of sophisticated attack. Aiming at the uncertain question in the attack process, this paper presents an intrusion intention recognition method based on Dynamic Bayesian Networks(DBN). Directed Acyclic Graph(GAG) is used to express the connection between attack behavior, attack plan and objectives, and the probabilistic reasoning method is used to predict next attack. Experiments reflect the change law of intrusion intention in the attack process, and proves the feasibility and validity.
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Computer Engineering. 2011, 37(8): 130-131. https://doi.org/10.3969/j.issn.1000-3428.2011.08.044
The defending ability of Dynamic Differential Cascade Voltage Switch Logic(DDCVSL) and SABL is restricted by layout and routing when they are used for protecting the circuit against differential electromagnetic analysis. Aiming at this problem, this paper gives an improved defend logic Masked Dynamic Differential Cascade Voltage Switch Logic(MDDCVSL) based on DDCVSL through introducing masking mechanism. NAND gates based on MDDCVSL, DDCVSL and SABL are designed with TSMC 0.18 μm technology. Experimental result demonstrates that the improved defend logic get rid of the electromagnetic information leakage and solve the problem that defend ability of MDDCVSL, DDCVSL and SABL are restricted by layout and routing. Meanwhile, MDDCVSL has less power consumption, area and delay than WDDL, MDPL.
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Computer Engineering. 2011, 37(8): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2011.08.045A fuzzy adaptive digital watermark algorithm which based on chaos mapping and two-dimension wavelet transform is proposed to protect the copyrights of multi-media data effectively. The proposed algorithm encrypted the watermark by a chaos sequence using Lorenz chaotic mapping method. The host image is transformed by discrete wavelet, then the watermark is embedded into it according to the embedding strength of watermark decided by fuzzy controller. Experiment and performance analysis result shows that watermark generated by the proposed algorithm has good invisible secure and robust characteristic.
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Computer Engineering. 2011, 37(8): 135-136. https://doi.org/10.3969/j.issn.1000-3428.2011.08.046
To improve the data processing speed of intrusion detection system and reduce the data imbalance, this paper presents a Fast Hierarchical Nearest Neighbor(FHNN) resampling method by analyzing existing resampling methods commonly and according to the characteristics of network intrusion detection datasets. The novel algorithm experiments with KDD’99 datasets. Experimental results show that this method is efficient in tacking noise and majority class examples. It is a rapid and effective method for detecting many types of threats from massive audit data.
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Computer Engineering. 2011, 37(8): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2011.08.047An asymmetric encryption and decryption method based on the fingerprint feature point topological structure transformation is designed, which can be applied to the network communication security. From the perspective of the fingerprint minutiae topological structure transformation and the topological equivalent, the feasibility and correctness of encryption and decryption is verified, and its anti-attack capability and computing speed are researched. Results show that it has features of fitful for the biologic identification and the strong capability of anti-attack, the fast speed of encryption and decryption. The method is simple and takes less resource, and is suitable to be designed and realized by intergraded circuit.
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Computer Engineering. 2011, 37(8): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2011.08.048Signcryption is such a public key cryptographic primitive that simultaneously provides the functionality of signature and encryption within a single logic step. Ring signature allows a member in a group to anonymously leak a secret, namely anonymity. Combining the two notations of signcryption and ring signature together, it leads to a concept called ring signcryption. Ring signcryption is an important cryptographic primitive for private and authenticated communication. This paper proposes an efficient Short Ring Signcryption(SRSC) scheme based on bilinear pairings. In anonymous communications, the scheme allows the message sender to send the message anonymously, while the confidentiality and authenticity of the message are realized at the same time. It proves that the scheme is confidential and unforgeable in random oracle.
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Computer Engineering. 2011, 37(8): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2011.08.049A dual video watermark scheme based on Contourlet transform is proposed. Performed Contourlet transform on I-frame in MPEG system, and srambled and encrypted watermark using hyperchaos sequence generated by simple two-dimentional hyperchaos system. Low frequency coefficients embedded destructive watermark to lose the video’s value and high frequency coefficients embedded robust watermark to protect copyright. Experimental results show that only authorized users can get high-fidelity video information and the algorithm provides a new way for video copyright protection.
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Computer Engineering. 2011, 37(8): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2011.08.050
In order to protect the security of a digital image effectively, this paper proposes an image encryption algorithm based on wavelet expansion function and hyperchaotic system. The pixel locations of the image are scrambled with a wavelet function, and the relationship between the original image and the encrypted image is disrupted with hyper-chaos system. The many parameters are inserted in four-step Runge-Kutta method in which chaos sequence of hyper-chaos system is gotten, to expand the space of parameter. Simulation experimental result show that the random behavior of gray value distribution of the encrypted image is better and the method can defends attacks.
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Computer Engineering. 2011, 37(8): 149-152. https://doi.org/10.3969/j.issn.1000-3428.2011.08.051A new multiple policy selection Genetic Algorithm(GA) based on reinforcement learning is proposed to avoid the premature convergence and low speed of convergence. The whole population is divided into three sub-populations and each of them evolves respectively by using several different selection policies, which improves the diversity of population and avoids the premature convergence effectively. Population diversity is associated with the running mechanism of the algorithm, and the parameters of the sub-populations are optimized dynamically using reinforcement learning according to the variance diversity, which can maintain the population diversity in the appropriate range and it solves the contradiction between convergence speed and global convergence to a certain extent. Experimental results show that the algorithm has a high performance in precision of convergence and search efficiency.
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Computer Engineering. 2011, 37(8): 153-154. https://doi.org/10.3969/j.issn.1000-3428.2011.08.052
Aiming at the disadvantage of unsupervised method and supervised method, a linear dimensionality reduction method called Semi-supervised Local Discriminant Analysis(SLDA) is proposed. When there is no sufficient training sample, local structure is generally more important than global structure. SLDA utilizes the labeled data points to infer the local discriminant structure, as well as the intrinsic geometrical structure inferred from both labeled and unlabeled data points at each local area. Experimental results on ORL and Yale face recognition demonstrate the effectiveness of the algorithm.
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Computer Engineering. 2011, 37(8): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2011.08.054
In order to enhance the ensemble of the traditional AdaBoost algorithm and reduce its complexity, two improved AdaBoost algorithms are proposed, which are based on the correlation of classifiers. In the algorithm, Q-statistic is added in the training weak classifiers. Every weak classifier is related not only to the current classifier, but also to the previous classifiers as well, which can effectively reduce the weak classifier similarity. Simulations show that the algorithm is of better detection rate and lower false alarm rate.
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Computer Engineering. 2011, 37(8): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2011.08.055Artificial Fish Swarm Algorithm(AFSA) is a novel intelligence optimization algorithm, which may effectively avoid local optimum solution and find the global optimum solution. But the algorithm has several disadvantages such as the poor ability to keep the balance of exploration and exploration for the discrete optimization problems. To overcome the problems, an algorithm with normal mutation operator is proposed. It can dynamically adjust the vision and congestion operator. In the bi-level programming model for discrete network design problems, the upper model is solved by AFSA with normal mutation operator and lower model by the Frank-Wolfe algorithm. Simulation results demonstrate this algorithm is efficient and effective, and it is suitable for applying to large scale road network.
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Computer Engineering. 2011, 37(8): 164-165. https://doi.org/10.3969/j.issn.1000-3428.2011.08.056A facial expression recognition method based on Sparse Preserving Projections(SPP) is proposed in this paper. It aims to preserve the sparse reconstructive relationship of the expression data, simultaneously, local neighborhood information is preserved during the dimension reduction procedure. It can extract more useful and discriminatal expression features from the orginal expression data, and the obtained projections are more stable. Experimental result on JAFFE and CED-WYU show that this method is an effective method for improving the recognition accuracy
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Computer Engineering. 2011, 37(8): 166-168. https://doi.org/10.3969/j.issn.1000-3428.2011.08.057In order to effectively solve the rotation changes, lighting changes and scale changes in the problem of image classification difficulties, a novel image classification algorithm based on multi-scales Local Binary Pattern(LBP) pyramid feature is proposed. It builds a multi-scales LBP pyramid to extract image texture features. It makes up the multi-scales LBP pyramid histograms by the extracted features. The dimensionality of multi-scales LBP pyramid histograms is reduced by kmeans clustering for image classification. The analysis of experimental results proves that the proposed algorithm has better discriminative power and image description ability. Furthermore, aiming at the drawback of convention weighting scheme based on the binary feature matching, it also proposes a new weighting scheme named multi-dominant feature weighting. Experimental results show this method actually improves the performance of classification.
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Computer Engineering. 2011, 37(8): 169-171. https://doi.org/10.3969/j.issn.1000-3428.2011.08.058Chinese organization names recognition is researched, and a new approach is proposed to recognize Chinese organization names, which combines Cascaded Conditional Random Fields(CCRF) with rules. Adding some effective rules in CCRF model and using effective feature model templates, it helps complicated organization names recognition for making decision for defect of character model. Experimental result shows the precision is 89.92%, recall is 91.41%, F-measure is 90.66% in People’s Daily(January, 1998), which proves the validity of the approach.
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Computer Engineering. 2011, 37(8): 172-174. https://doi.org/10.3969/j.issn.1000-3428.2011.08.059To overcome the problems of premature convergence frequently and low accuracy computationin in Particle Swarm Optimization (PSO), a novel hybrid algorithm, called hybrid EPSO, is proposed. Extremal Optimization(EO) is introduced into PSO at a certain iteration intervals. The hybrid algorithm uses the volatility of EO to increase the diversity of population, on the other hand, it elegantly combines the exploration ability of PSO with the fine-grained ability of EO, it avoids premature convergence of PSO with high accuracy. Simulation experimental results show that the hybrid algorithm is an effective way to locate global optima of continuous multimodal functions of high dimensions.
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Computer Engineering. 2011, 37(8): 175-176. https://doi.org/10.3969/j.issn.1000-3428.2011.08.060
Particle Swarm Optimization(PSO) algorithm is proposed to solve the problem of mining enterprises dynamic allocation. The mineable ore blocks can be marked according to mining conditions delineated, with a bit of ore particles to represent a mine block, and the selected ore mining block is represented by 1, and the constrained PSO particles computing and “flight” rule is re-defined and the dynamic allocation ore particle swarm algorithm is realized. The PSO algorithm implementation is simple, the optimum effect is obvious, the comparison of actual production in 2009 and the optimization results shows that the algorithm improves enterprise efficiency significantly when the cost of production is almost unchanged.
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Computer Engineering. 2011, 37(8): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2011.08.061This paper researches on an improved Harmony Search(HS) for No-Wait Flow Shop(NWFS) schedule problem. The model of NWFS is built and the total flow time is calculated. Large position value rule is used to realize HS solving NWFS schedule. Optimum is improved using variable neighbor search based on interchange neighbor and insert neighbor. Simulations and comparisons based on well-known benchmarks demonstrate the efficiency, effectiveness and robustness of the proposed algorithm.
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Computer Engineering. 2011, 37(8): 181-182. https://doi.org/10.3969/j.issn.1000-3428.2011.08.062
Manually creating multiple labels for each sample is very important but it is time-consuming. Manually creating multiple labels for each sample may become impractical when a very large amount of data is needed for training multi-label classifier. To minimize the human-labeling efforts, this paper proposes a weighted decision approach, the approach considers quantity and confidence of training samples, it can make the classifier need fewer samples, but achieve a comparative precision.
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Computer Engineering. 2011, 37(8): 183-185. https://doi.org/10.3969/j.issn.1000-3428.2011.08.063In order to improve the accuracy of intrusion detection, this paper puts forward a classifier integration method which uses tabu genetic search. It uses Bagging algorithm to found classifiers. It adopts tabu genetic search to select classifier, and uses the selected classifiers to establish an intrusion detection system. Experimental results show that compared with Bagging algorithm, this method can improve detection accuracy and reduce false alarm rate.
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Computer Engineering. 2011, 37(8): 186-189. https://doi.org/10.3969/j.issn.1000-3428.2011.08.064Owing to the special structure of handwritten Kazakh characters, just using several simple features to recognize Kazakh characters encounter the problems of low recognition rate and poor recognition effects. This paper determines the word baseline by using improved PCA method, extracts 36 features for each character and the K-W checking is used to compare the classification ability of each feature. It uses the linear discriminant function to classify the characters and acquires a higher recognition rate. Experimental result shows that to off-line handwritten character the recognition accuracy achieves 94％.
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Computer Engineering. 2011, 37(8): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2011.08.065Adjusting genetic parameter adaptively is a complex and uncertain process. Based on the cloud model, which can represents the uncertain knowledge, an improved adaptive Genetic Algorithm(GA) is proposed, and its basic principle and implementation strategy are discussed, the proposed method takes nature language as the cut-in point, and depicts uncertain prior rules by cloud model, adjusts the parameters of GA through cloud controll. Experiments of function optimization show that the proposed algorithm simulates the uncertain procedure of parameter adjusting, and its results are feasible and effective.
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Computer Engineering. 2011, 37(8): 192-193. https://doi.org/10.3969/j.issn.1000-3428.2011.08.066
The construction of scenario map is one of key activities in the process of chance discovery. The formalization description of the structure of scenario map in chance discovery is presented. With this formalization description, the principle for the construction of event clusters in scenario map via clustering analysis based on Boolean correlation matrix and the construction of simple scenario map based on event clusters are given and the algorithm for the implementation of the principle is given. The evaluation criterion for the performance of methods for the construction of scenario map in chance discovery is discussed and efficiency coefficient is used as the criterion definitely. Experimental results show that the performance of the algorithm on the construction of simple scenario map is good with greater efficiency coefficient.
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Computer Engineering. 2011, 37(8): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2011.08.067Extracting embedded text from images to filter image spam is usually time-consuming and can not reach high classification accuracy. On the other hand, filtering image spam using image properties features has low recall rates problem. This paper proposes a simple but effective method to detect image spam. By tokenizing Base64-encoded image text into a series of 4-gram features and representing them as a binary vector, a trained Support Vector Machine(SVM) can distinguish spam images from legitimate ones very well. Experimental results show that the method achieves satisfactory performance in filtering image spam with different formats, with the precision, recall and F1 of 99.85%, 99.49% and 99.67% respectively.
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Computer Engineering. 2011, 37(8): 197-198. https://doi.org/10.3969/j.issn.1000-3428.2011.08.068Based on the analysis of Uyghur character structure features, this paper studies the characteristics of Uyghur character in wavelet transform and according to these characteristics it presents a localization method of Uyghur character in the video image based on wavelet transform. By using local time-frequency and multi-scale featured wavelet analysis method, distinguished texture features with different space resolutions and the edge components with different directions sub-image are extracted. Then by mathematical morphology method, the useless information is greatly decreased and the ultimate target text region is acquired. Experiments show that the proposed method can detect text effectively and is suited for the localization of Uyghur characters in complex background.
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Computer Engineering. 2011, 37(8): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2011.08.069Aiming at the complex and long training process of face detection, this paper addresses the problem of learning to detect faces from a small set of training samples. It proposes to use covariance features to extract the facial features. For better classification performance, linear hyperplane classifier based on Fisher Discriminant Analysis(FDA) is proffered. AdaBoost algorithm is used to construct cascade classifier. It shows that the detection can be significantly improved with the algorithm on a small dataset, compared with Haar-like features used in current most face detection systems.
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Computer Engineering. 2011, 37(8): 202-203. https://doi.org/10.3969/j.issn.1000-3428.2011.08.070
The performance of semi-supervised learning algorithm can be enhanced by incorporating the structural information of the dataset. Based on this assumption, a novel graph-based semi-supervised learning method is proposed. A local scale scheme is presented to define different scale parameters for edge weights in different density regions. The dataset is classified by a semi-supervised learning algorithm named graph Laplacian kernels. Experiments on several datasets show that the proposed method outperforms other kernel-based semi-supervised learning algorithms.
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Computer Engineering. 2011, 37(8): 204-206. https://doi.org/10.3969/j.issn.1000-3428.2011.08.071
This paper presents a kind of parking cell detection method based on KL transform and kernel fisher discriminant. It preprocesses the parking cell images. The parking cell images is projected onto the eigen-parking cell-subspace which is constructed by KL transform, and the coefficients of the projection are the eigen-vector of the parking cell. It makes use of kernel fisher discriminant to determine the occupancy of parking cell. In the experiment, it uses three different kernel functions to compare the results of the fisher discriminant. Experimental results indicate that the parking cell detection method with Radial Basis Funtion(RBF) kernel function is superior to other methods, the correct detection rate reaches as high as 97.6%.
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Computer Engineering. 2011, 37(8): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2011.08.072The Adaptive Niche Genetic Algorithm(ANGA) can overcome the deficiency of Sample Niche Genetic Algorithm(SNGA) such as complicated operation and time-consuming, maintain stability of the groups, and obtain appropriate scope of the individual, as to get optimal solution best. In order to obtain the hull form with the excellent resistance performance, an optimization design model of hull form is proposed based on the Rankine source method of potential flow theory. The adaptive niche genetic algorithm combined with the CAD technology to solve the problem. The optimization examples for S60 ships are provided, which confirm that the algorithm is reliable.
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Computer Engineering. 2011, 37(8): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2011.08.073Particle Swarm Optimization(PSO) algorithms may easily get trapped in a local optimum, when it solves complex multimodal problems, by analyzing the relationship between swarm diversity and local optima, this paper presents an improved particle swarm optimizer based on dynamic neighbor topology(DPSO for short). In DPSO, the neighbor of each particle is dynamically constructed at several iterations, which increases the swarm diversity and improves the ability to escape from local optima. In benchmark functions, the DPSO algorithm achieves better solutions than other PSO algorithms.
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Computer Engineering. 2011, 37(8): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2011.08.074To improve the prediction precision in credit evaluation, a novel classifier ensemble algorithm based on Gene Expressiong Programming(GEP) with Bagging, called BGEP-CREDIT, is proposed. The algorithm uses Bagging to combine the several GEP classifiers generated from GEP. Experiments and performance analysis on Germany credit database are given. The results show that compared with SVM algorithm, KNN(K=17) algorithm and a single GEP classifier, the prediction precision is increased by 2.7%, 7.93% and 1.1% respectively by using BGEP-CREDIT.
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Computer Engineering. 2011, 37(8): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2011.08.075A method of path planning for underwater vehicle based on Binary Quantum-behaved Particle Swarm Optimization(BQPSO) algorithm is proposed aiming at the grid discrete workspace. In this algorithm, the path is represented as binary code of the particle position. The length of path is set as function fitness and the crossover is introduced to avoid the local minima. Simulation experiments show that BQPSO algorithm can effectively avoid the obstacle of the underwater vehicle.
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Computer Engineering. 2011, 37(8): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2011.08.076Fingerprint segmentation is one of the key steps of fingerprint identification system, which are relation to its performance. It researches the spectrogram and traditional segmentation method based on block of fingerprint images, and calculates the average fingerprint ridge distance, according to spectral energy distribution of the map, then proposes to divide the image into non-overlapping rectangular block according to physiological characteristics of the human body. The block size is automatically determined in the algorithm implementation process, according to the characteristics of frequency spectrum. Experimental results show this algorithm is adaptive to be significantly higher than the traditional ones, for images of different resolutions and quality.
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Computer Engineering. 2011, 37(8): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2011.08.077Traits of neural network theory and fuzzy measurement method are discussed. A method of the further fusion diagnosis using neural network and fuzzy measurement is proposed. The method uses observational data, integrates diagnosis methods with subjective and impersonal information, which can realize the complementary fusion diagnosis, identify fault more comprehensive and objective, and efficiently improve the fault location capability. A hydraulic equipment fault diagnosis example proves the effectiveness of this method.
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Computer Engineering. 2011, 37(8): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2011.08.078A blind digital image forensics method is proposed based on tensor decomposition to detect the authenticity of JPEG compressed image in global processing view. Image features are extracted from decomposition residual, which are obtained via tensor decomposition of a group of reference images shot by the claimed camera. Then the Support Vector Machine(SVM) classifier is applied to classify whether the image is from the claimed camera or not. Experimental results show that this method has high accuracy and strong robust.
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Computer Engineering. 2011, 37(8): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2011.08.079
Aiming at the problem of fragment matching in 3D fragment reassembly, this paper proposes a rapid contour curve matching algorithm. In the algorithm, the curve is expressed by B-spline curve, and curvature, torsion and normal vector are calculated. In the matching process, the type of feature point is classified according to its neighbor surface, and the similarity of the two feature section is measured according to the Euclidean distance of the feature points. The normal vector is used to verify the matching probability of similar space curves. Experimental results show that the algorithm is stable and efficient.
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Computer Engineering. 2011, 37(8): 231-232. https://doi.org/10.3969/j.issn.1000-3428.2011.08.080Aiming at the problem that the image segmentations based on graph theory have to use the image pre-processing to resist noise, this paper presents an image segmentation method with noise immunity. The proposed algorithm uses the normalized graph spectral cut measure as the thresholding principle to distinguish an object from the background. Instead of commonly using the image pixels, the algorithm uses the weight matrices based on the gray levels of an image to describe the relationship between image pixels. In order to improve the ability of resisting noise, the correlation between the pixel and its neighborhood is added in the graph weight computation. Experimental results show that the method of image segmentation has a very good segmentation results, and a strong ability to resist noise.
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Computer Engineering. 2011, 37(8): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2011.08.081To make the identification of the pneumoconiosis’ X-ray films easier, this paper proposes an image enhancement method for films of pneumoconiosis based on Weighted Local Area Histogram Equalization(WLAHE). It uses WLAHE, Local Area Histogram Equalization(LAHE) and Histogram Equalization(HE) to enhance the contrast of the pneumoconiosis’ X-ray film of stage 0+. The enhancement effect of them with different parameters is compared with each other. Results show that WLAHE can make the small pathological changes opacities in the pneumoconiosis’ X-ray film of stage 0+ more prominent with smaller windows and results in less noise and distortion of details.
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Computer Engineering. 2011, 37(8): 236-237. https://doi.org/10.3969/j.issn.1000-3428.2011.08.082
This paper proposes a fuzzy-cut best wavelet packet image compression algorithm. The ratio of each high-frequency coefficient to the total high-frequency coefficients of wavelet packet decomposition and the ratio of each node’s children entropy to the original node entropy are defined as two inputs of the fuzzy system. The wavelet packet coefficients are divided into cutting part and the best wavelet packet is got by the reservations parts. The image is compressed by using the different thresholds on different wavelet packet transform level based on the best wavelet packet. Simulation results show that the algorithm has better performance than the rate-distortion and the whole thresholds wavelet packet image compression algorithm.
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Computer Engineering. 2011, 37(8): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2011.08.083This paper designs a resource-oriented geospatial information service by combining with the Representational State Transfer(REST) Web Service and Open Geospatial Consortium(OGC) specification. In order to achieve information sharing and interoperability, OGC specification is adopted as the service interface standard. REST is adopted to implement services, and is opened to the public in the form of resource. A uniform interface is shared by all of the resources which transfer between the server and the client.
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Computer Engineering. 2011, 37(8): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2011.08.084This paper introduces the single machine total weighted tardiness model with sequence dependent setup times to research Printed Circuit Board(PCB) assembly problem with boards of different types by using a single automated surface mounting line. An improved Ant Colony Optimization(ACO) algorithm is developed for the model. The improved algorithm uses new pheromone upgrade mechanism with tabu table to avoid algorithm from premature convergence. Interactive local search is realized by multithread, and path pool is used to communicate local search and ACO. Test result shows that the improved algorithm can effectively improve the efficiency of PCB assembly, and reduce manufacturing tardiness of the tasks.
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Computer Engineering. 2011, 37(8): 244-245. https://doi.org/10.3969/j.issn.1000-3428.2011.08.085To make the embedded devices access to Internet more conveniently, considering the advantages of simple networking and no-wiring of Wireless Fidelity(Wi-Fi) technology, this paper applies Wi-Fi in embedded devices’ communication and interconnection with Internet. It studies the integration method of Wi-Fi technology and embedded devices, and proposes the formation mode of wireless Wi-Fi monitoring system, which resolves the communication problem between Wi-Fi module and embedded devices, and provides a feasible solution for embedded devices’ remote data transmission and wireless monitoring.
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Computer Engineering. 2011, 37(8): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2011.08.086There are some disadvantages of high power dissipation, low speed and so on when the general microcontroller is used to implement the Logical Link Control(LLC) sub-layer of Dedicated Short-Range Communication(DSRC) in Electronic Toll Collection(ETC) system. By analyzing working principle of LLC sub-layer protocol of on-board unit in ETC system, this paper proposes a LLC sub-layer protocol which is implemented by specific logical circuit. The state transition modes of two types of services are presented. The function of LLC sub-layer is realized in Verilog HDL, and FPGA experimental results show the effectiveness of the method.
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Computer Engineering. 2011, 37(8): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2011.08.087
In order to meet high reliability and real-time requirement of embedded systems, this paper proposes a multi-task parallel IEEE1394 protocol stack model by using the hardware and software feature of IEEE1394 bus. And the data transmission of different quality of services is acquired by setting different tasks’ priority. The execution of task and command of IEEE1394 subsystem take on higher real-time performance. The feasibility is testified by implementing digital video decoding and Serial Bus Protocol 2(SBP2) mobile storage based on the protocol stack on VxWorks platform.
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Computer Engineering. 2011, 37(8): 252-255. https://doi.org/10.3969/j.issn.1000-3428.2011.08.088It is necessary to realize the Abstract Syntax Notation One(ASN.1) for Radio Resource Control(RRC) in development of Long Term Evolution(LTE) protocol, but the efficiency of traditional method is low. Aiming at this problem, this paper proposes a novel design method of ASN.1 encode/decode module to meet the requirement of LTE protocol stack. The method adopts modular design, simplifies function call and improves code efficiency. It realizes and tests ASN.1 encode/decode module in TD-LTE wireless comprehensive measurement instrument. Testing the functions of this module, it proves the effect of module to encode and decode in RRC information of LTE protocol stack. It is practically useful and owns promotional value.
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Computer Engineering. 2011, 37(8): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2011.08.089
For solving the vehicle routing problem with disruption that may be vehicle breakdowns or traffic accidents in the logistics distribution system, this paper builds a mixed integer programming disruption management model. For the attributes of the vehicle routing problem with disruption, a series of solving-simplify strategies are given to simplify the solution space. On the basis of the characteristic of the model, the improved saving algorithm based on disturbed value is designed based on the disruption value. Numerical experiments from multiple wheel-driven vehicle scheduling problem and vehicle scheduling interference management problem are given to prove the efficiently of the disruption management model and algorithm.
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Computer Engineering. 2011, 37(8): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2011.08.090In the traditional subspace speech enhancement algorithm, the bias of the estimated speech eigenvalues leads to speech distortion and residual noise. A new algorithm is advanced to correct them. The algorithm adjusts adaptively coefficient ahead noise eigenvalues jointing masking effect, modifies concurrently the clean speech eigenvalues by wiener filter for its restraint to noise especially music noise, attains the clean speech. Experimental results show that the proposed algorithm can achieve the higher SNR than the traditional algorithm in the same Gaussian white noise and train colored noise, and reduce speech distortion and residual noise.
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Computer Engineering. 2011, 37(8): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2011.08.092In order to reduce complexity of fixed codebook search, a fast algebraic codebook search argorithm based on pulse replacement procedure is proposed in this paper. The proposed method is employed dividing candidate codevector into two sub-codevectors to optimize. It not only lowers the computational complexity sharply, but also ensures the speech quality. Experimental results show that the proposed method reduces the total computational complexity by 70%~80% with speech quality equivalent, compared with that by the depth-first tree search method adopted in AMR-WB and traditional pulse replace method.
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Computer Engineering. 2011, 37(8): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2011.08.093
Based on the modularized and parametric design, a model of module library management system is presented considering the special demand of collaborative sharing mode for supporting networked rapid design of automatic weapons. The design procedure for 3D models of rapid design platform of automatic weapons is described. In order to transfer data accurately and effectively, the multi-thread transferring method of models and compression program based on hierarchy of assemblies are put forward and realized ultimately.
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Computer Engineering. 2011, 37(8): 271-274. https://doi.org/10.3969/j.issn.1000-3428.2011.08.094This paper proposes an on-line task reservation reschedule algorithm for reconfigurable system based on Minimum Laxity First(MLF) policy. Based on the task reservation, it reschedules the tasks which fail in previous reservation and tasks which are already reserved, according to certain priority policy. Simulation result shows that under normal system load range, the algorithm effectively reduces the task rejection ratio while keeping runtime overhead manageable.
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Computer Engineering. 2011, 37(8): 275-277. https://doi.org/10.3969/j.issn.1000-3428.2011.08.095This paper proposes a multimedia resource retrieval method under data grid environment. It designs a layered virtual resource space to manage multimedia data which are not structuralized and heterogeneous. When the system receive query request from a query node, the filtration process is triggered based on virtual sets and metadata. After the filtration candidate set is selected and only corresponding features and labeling information are transferred to the executing nodes in a package mode. The executing nodes are responsible for similarity computing and ranking. Final retrieval results are transferred from data node to the query node according to the ranking results. Simulation results show that this method is effective both on accuracy and time.
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Computer Engineering. 2011, 37(8): 278-280. https://doi.org/10.3969/j.issn.1000-3428.2011.08.096This paper proposes a hardware pipelining processor for single-threads with granularity of code block. It makes use of compile technique to parallel program and divides program into blocks. Some blocks are arranged to be executed at processor’s idle units to improve performance. The processor needs compiler support, but has less of modification to primary processor. Results show that spec2000 test program gets 40% performance improvement after using this processor.
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Computer Engineering. 2011, 37(8): 281-284. https://doi.org/10.3969/j.issn.1000-3428.2011.08.097To solve management problem of computing resources in high performance computing system in National Meteorological Information Center(NMIC), this paper proposes a management system of meteorological computing resources. It describes the relation of computing resources and end users by bank account. The use of the computing resources is thought as deposit and charging. The system implements the functions for resources charging, allocation and statistics functions by database technology. Application result shows that the computing resources are managed real-time and subtly.
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Computer Engineering. 2011, 37(8): 285-287. https://doi.org/10.3969/j.issn.1000-3428.2011.08.098Considering that the client devices are usually small, maintained by constrained battery in Wi-Fi positioning, this paper proposes a fast Wi-Fi positioning algorithm based on clustering. Through grouping reference points with similar signal strength together and then locating, the algorithm not only reduces the computation in positioning phase, but also achieves a high accuracy at the same time. Experiments are conducted in campus and the business district respectively, and the results demonstrate that Root Mean Square Error(RMSE) is reduced from 16.71 m to 9.68 m, the positioning time is reduced from 96.3 ms to 5.2 ms. Experimental results indicate that the algorithm is effective and available.
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Computer Engineering. 2011, 37(8): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2011.08.099
This paper presents a simulation method for Taihu Lake blue-green algae outbreak process based on WSN and particle system theory. It adopts the technology of embedded system and designs an online measurement system based on temperature and transparency. According to the established mathematical models, it carries on the simulation of bloom in Taihu Lake with OpenGL. Practice result proves that the method which satisfies the general requirements of real-time display under general PC has good simulation performance for the outbreak process of algae.
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Computer Engineering. 2011, 37(8): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2011.08.100Fog effect can enhance the realism and distance of scene. Linear, exponential and exponential-squared fog parameters are enumerated in Direct3D, and they make the real-time rendering rapid and convenient, however, the various transformations of fog are limited by the only three parameters. Fog factor is the key to define the formula of parameters, and vertex shader has the ability to render vertex separately. This paper discusses a way to reconstruct the formula of fog factor by combination of the features above, gives an example, which can implement the fog effect according to the altitude of scene, the distance between observer and scene and the density of fog. Experimental results show that the restriction of original parameters can be improved in this way, and fog effect in reality can be imitated freely.
Volume 50 No 3
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