05 March 2012, Volume 38 Issue 5
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Computer Engineering. 2012, 38(5): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2012.05.001
This paper proposes a foreground moving object detection method based on Gaussian Mixture Model(GMM) and codebook. It uses GMM to extract initial foreground object, learns the background in use of codebook. It associates the foreground object obtained by GMM with the object of codebook foreground, updates the parameters of Gaussian model and codebook adaptively, according to the ratio between the foreground in 2 adjacent frames, and gets the moving object. Experimental results show that the method can eliminate the shadow of the video sequence and ghosting effectively, as well as obtain the entire foreground object in real time.
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Computer Engineering. 2012, 38(5): 5-8. https://doi.org/10.3969/j.issn.1000-3428.2012.05.002
Aiming at freely editing human motion posture, Bézier curve and number data are used in human motion posture editing. According to the feature of human motion, virtual body models are constructed in the use of OpenGL in VC++. Combing the motion capture technology, the simulation of virtual people are realized. Based on the normal range of human joints, the human key joint are researched in the experiment. In the use of collected human motion data, the simulation program can drive virtual body model, which is widely used in the field of medical, education, robots simulation.
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Computer Engineering. 2012, 38(5): 9-13. https://doi.org/10.3969/j.issn.1000-3428.2012.05.003
For the demand of real-time on-line route planning, an algorithm is provided here for digital terrain data compression process based on sparse quadtree’s hierarchical storage. The principle is introduced for math modeling and data compression of threats with nonformula geometry shape. The data structure and storage method are analyzed for Digital Elevation Model(DEM) data decomposed by quadtree algorithm. Another data compress algorithm is designed which is to divide the terrain data by multi-resolution sparse quadtree with the preplanned route as its center. The data updating process is described for the precision improvement of terrain data during real-time on-line application. The numerical simulation proves the mentioned validation of the method.
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Computer Engineering. 2012, 38(5): 14-18,24. https://doi.org/10.3969/j.issn.1000-3428.2012.05.004
Traditional user models can not describe the interest of the experts in Cyberspace for Workshop of Metasynthetic Engineering(CWME) well. To meet this challenge, this paper proposes a new expert interest modeling method. This method uses Non-negative Matrix Factorization(NMF) to generate the elaborate topics, then works out the interest segments of an expert step by step through analyzing the relationship between the expert's speech and topics. The model is finally built by integrating all the interest segments of the expert. Experimental results show that the proposed model can predict discussion domain accurately and is helpful to recommend personalized information for participants in CWME.
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Computer Engineering. 2012, 38(5): 19-24. https://doi.org/10.3969/j.issn.1000-3428.2012.05.005
This paper introduces the special frequency and direction properties of contrast sensitivity of human vision into the calculation of Structural Similarity(SSIM), and proposes a new structural similarity quality assessment method, called Frequency Direction Sensitive Structural Similarity(FDSSS). The value of each sub-band SSIM of the wavelet-decomposed image is calculated. To reflect the direction sensitivity of CSF, SSIM values of sub-bands under the same decomposition level with different directions are weighted according to their relative energy. To reflect the frequency sensitivity of CSF, SSIM values of each decomposition level are weighted based on the frequency magnitudes of each sub-band of CSF. Simulations results in LIVE2 and TID2008 database show that the proposed method is more consistent with subjective evaluation and outperforms than several other popular image quality assessment methods.
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Computer Engineering. 2012, 38(5): 25-29,34. https://doi.org/10.3969/j.issn.1000-3428.2012.05.006
This paper proposes a shilling attack detection model for recommender system based on memory principle. By combining biological memory principle and mathematics statistics, it detects shilling attacks through the memory cell’s characteristics. The characteristic memory database can update timely, so that costs of system are saved. Experimental result shows that the model improves the ability of detecting shilling attacks of recommender system.
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Computer Engineering. 2012, 38(5): 30-34. https://doi.org/10.3969/j.issn.1000-3428.2012.05.007
For settling a problem that Binary Space Partition(BSP) tree of in-out polygon algorithm degenerates into line list, this paper presents an improved judgment algorithm of point in-out polygon. The algorithm sorts Y value per node in polygon. It travels all horizon lines by way of binary. BSP tree is always balance binary tree. The time complexity of the BSP-Tree searching is O(lbn). Experimental results show that the improved algorithm makes sure that time complexity for the query of binary space partition trees is always high efficient while time complexity for the construction of BSP trees does not increase. Meanwhile, it has good versatility.
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Computer Engineering. 2012, 38(5): 35-37,40. https://doi.org/10.3969/j.issn.1000-3428.2012.05.008Traditional program instrumentation can increase the executing time greatly and bring a great code bloat. In order to eliminate the impact of program instrumentation, a strategy based on control flow path coverage for executable code to eliminate redundant is presented. And a unit test tools for Java executable code is designed to achieve program execution path tracking and coverage analysis. Results show that both the number of instrumentation probes and runtime overhead of instrumentation are reduced effectively.
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Computer Engineering. 2012, 38(5): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2012.05.009Considering deficiencies of some popular data stream clustering algorithms, a data stream clustering algorithm based on density and fractal dimension is presented. It consists of two phases of online and offline processing, combined with the advantages of density clustering and fractal clustering. The deficiency of the traditional clustering algorithm is overcome. In the algorithm, a density decaying strategy to reflect the timelines of data stream is adopted. Experimental results show the algorithm improves the efficiency and accuracy of data stream clustering, and can find arbitrary shapes and non-neighboring clusters.
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Computer Engineering. 2012, 38(5): 41-43,46. https://doi.org/10.3969/j.issn.1000-3428.2012.05.010This paper designs a database cluster architecture based on middleware technology to meet users’ high-input and high-output applications, and proposes a load balancing algorithm based on Markov model for the database cluster. The algorithm forecasts the load information of all execution nodes using Markov model within the period of sampling execution node load information, and balances the loads on all executor nodes using the above load prediction results. Experimental result shows that the proposed algorithm can improve the performance of database cluster effectively.
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Computer Engineering. 2012, 38(5): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2012.05.011Aiming at the complexity of network fault and a huge amount of information in alarm database, this paper proposes an improved incremental association rule mining algorithm. It uses incremental association rule mining only on the update data, combines the traditional analysis of alarm and the association rules mining. The algorithm is applied into the application of fault alarm correlation analysis in the network. Experimental results show that the algorithm can reduce the redundant rules, and improve the efficiency of mining.
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Computer Engineering. 2012, 38(5): 47-49,55. https://doi.org/10.3969/j.issn.1000-3428.2012.05.012To solve the problem of massive storage system fault tolerance, this paper defines I/O fault models based on SCSI, designs and implements an evaluation platform based on SCSI protocol. It modifies SCSI commands from upper layer, passes them to the lower layer. As the tool can modify the commands, many faults can be injected. Experimenal results show that system has different fault tolerance to different faults, therefore the performance index of different storage system can be compared.
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Computer Engineering. 2012, 38(5): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2012.05.013This paper analyzes TCAR algorithm of temporal constraint. It is very inefficient on mining frequent temporal sets with this method. As to the disadvantage of this algorithm, a new method of mining temporal association is brought up. According to the new method, the original databases are dealt with to reduce the memory. On the basic of mining the most frequent items algorithm on the sequences of sets, the grouping terms for most frequent temporal sets are mined. Practical example analysis results show that the algorithm can improve the efficiency of mining.
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Computer Engineering. 2012, 38(5): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2012.05.014In order to reduce energy consumption of large-scale data centers and realize load balancing to some extent, a method called Load Balancing and Energy Saving(LBES) based on Virtual Machine(VM) migration is introduced in this paper. It considers some problems such as the load situation of many kinds of resources, clustering conflict and so on, analyzes three critical procedures in the process of VM migration primarily and presents correspondent strategies. It comes true in Cloudsim. Experimental results show that this method is more excellent than other methods in performance, in the case of great imbalance of host machine load distribution.
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Computer Engineering. 2012, 38(5): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2012.05.015To solve the problem of automatic extraction from different DeepWeb result page structures, this paper proposes a method which combines the Web structure and the content of Web pages. This method uses the characteristics of data content and the DOM tree nodes which are marked by the domain ontology library positioning data area. An improved simple tree matching algorithm is used to identify data records. Experimental results show that the F-measure value of this method is 2.93%~6.67% higher than that of traditional methods.
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Computer Engineering. 2012, 38(5): 59-61,66. https://doi.org/10.3969/j.issn.1000-3428.2012.05.016In order to create a massive infrastructure composed of highly diverse interconnected mobile entities, form a united data management environment, a data management approach for large-scale mobile terminal called MTDM is presented and described in this paper. The registration, querying and data delivery of the mobile object entity are discussed. MTDM is a good and efficient system which is strongly supported by the cache and data directory technology. Results obtained from example analysis show that MTDM can implement the data sharing, storing and querying for mobile entities.
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Computer Engineering. 2012, 38(5): 62-63,69. https://doi.org/10.3969/j.issn.1000-3428.2012.05.017Aiming at the problem of high RAM and computation consuming in traditional data stream ensemble classification algorithm, it proposes an on-demand ensemble classification algorithm, which can revises the number of classifier and their weights on demand actively, so as to achieve the purpose of reducing cost while maintaining high classification accuracy. According to the experiments on two synthetic datasets, both classification efficient and accuracy have been improved in hidden concept drifting data streams, while the memory consumption has reduced significantly.
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Computer Engineering. 2012, 38(5): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2012.05.018Aiming at these problems of Internetware trust evaluation such as uncertainty, fuzzy and not being able to accurately described and verified, a fuzzy comprehensive evaluation method for Internetware is proposed which determines the various factors weights. It introduces information entropy theory. The method can overcome the shortcomings in determining the weight by the subjective judgments method, and improve dynamic adaptability of trust evaluation model, which is not strong enough as a result of subjective weight distribution by traditional methods. The case study shows the feasibility and effectiveness of the method.
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Computer Engineering. 2012, 38(5): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2012.05.019This paper proposes a personalized recommendation algorithm of Internet forum based on collaborative filtering. According to the users posting, replies, and reading records, it computes user rating matrix by weighted method, gets the nearest users, then calculates the target user’s posts prediction score according to neighbors’ posts, and recommends the highest score prediction posts to target user. Experimental results show that the algorithm can recommend high-quality posts.
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Computer Engineering. 2012, 38(5): 70-72,82. https://doi.org/10.3969/j.issn.1000-3428.2012.05.020According to the classical rough sets based on the equivalences, this paper presents the weak symmetric and partial strong symmetric binary relations, establishes the generalization rough set models based on the two relations. It gives the axiomatic characterizations of the two models. Combining both of the two models, it gets the generalized rough set model based on strong symmetric relation. Results of theoretical analysis demonstrate that a necessary and sufficient condition for that all sets of the universe are the generalized accurate sets is the binary relation on universe is a strong symmetric relation, namely, the model can be used to put up a characterization of the generalized accurate set in the classical rough sets.
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Computer Engineering. 2012, 38(5): 73-75. https://doi.org/10.3969/j.issn.1000-3428.2012.05.021This paper quantifies the developing level of Shanghai cultural Industry, uses gray theory to predict the culture developing situation in such a case that Expo is not hold in Shanghai. The prediction curve is compared with the curve got under the situation of holding Shanghai Expo so as to quantitatively evaluate the influence on Shanghai cultural industry development. And GM(1,1) model is applied to assess aftereffect for the later period of Expo.
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Computer Engineering. 2012, 38(5): 76-78,88. https://doi.org/10.3969/j.issn.1000-3428.2012.05.022In order to obtain expected collaborative paths among software entities, an approach is presented. By combining the UML and Pi-calculus, Pi-calculus semantics of behavior for software entities is extracted on the basis of behavior analysis for them. The collaboration among them is further deduced through Pi-calculus operational semantics, the expected collaborative path set is generated, and then it is stored in eXtensible Markup Language(XML). An example application of the approach is explained. Application results show that the approach provides an effective way to obtain expected collaborative paths among software entities. It is of complementary significance to the methods of obtaining expected software behavior in research of trusted software.
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Computer Engineering. 2012, 38(5): 79-82. https://doi.org/10.3969/j.issn.1000-3428.2012.05.023Based on the existing two-stage virtual network mapping algorithm, this paper proposes an improved algorithm to address the virtual network mapping problem by considering the impact of location constraints by combining the node resources migration and link splitting. Simulation results show that compared with the existing algorithm, the acceptance ratio of virtual network requests enhances by about 10%, the long-time average revenue increases by about 15%, and the benefit-cost ratio increase by about 12%.
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Computer Engineering. 2012, 38(5): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2012.05.024There are some problems such as detour or poor efficiency if using P2P in Mobile Ad Hoc Network(MANET) directly. By introducing P2P distributed sharing strategy into MANET, multihop routes are published and shared as information resources, and data are sent among nodes in the shortest paths, so that detour problems are solved. Experimental result proves that the method can increase the efficiency of MANET routing.
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Computer Engineering. 2012, 38(5): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2012.05.025There are some problems such as limited node energy and propagation delay of data when Wireless Sensor Network(WSN) is used in real-time applications. This paper proposes an improved routing protocol based on SPIN protocol. By comparing minimum number of hops, it controls propagation direction of data, and chooses a path with the best real-time performance to Sink. Simulation results show that the improved protocol can reduce the network energy consumption by reducing data packets in transmission, so that the network life cycle is extended.
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Computer Engineering. 2012, 38(5): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2012.05.026Aiming at Orthogonal Frequency Division Multiple Access(OFDMA) system, an improved admission control algorithm for multi-service is proposed in this paper. The system provides a number of sub-carriers for the transmission, compressing the channel bandwidth or the transmission rate, reducing the Quality of Service(QoS) of the service on the original channel, and the number of available channel in the cell can be raised. Simulation result shows that the algorithm can improve the channel resources utilization and reduce the call blocking probability which comes from the handover call and new call, compared with the conditional channel reservation algorithm.
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Computer Engineering. 2012, 38(5): 92-95. https://doi.org/10.3969/j.issn.1000-3428.2012.05.027Allusion to the problem that present network anomaly detection method based on traffic is still on the level with low accuracy, this paper proposes a new analysis and detection means on the base of decision tree. Network traffic structure feature and the method to describe network anomaly based on cross entropy are deeply researched then. C4.5 decision tree algorithm is used to establish decision model, attribute with continuous values are discreted, and attribute for classification layer by layer are selected on the base of maximum information gain ratio. Experimental results show that while the accuracy gets up to 90%, the misinformation rate can be controlled within 5%, which shows an obvious advantage compared with parallel method.
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Computer Engineering. 2012, 38(5): 96-98,116. https://doi.org/10.3969/j.issn.1000-3428.2012.05.028Aiming at the traditional deployment methods of mobile nodes in Wireless Sensor Network(WSN), there are some problems like non-uniform distribution and incomplete coverage of the nodes. To overcome this, a new assignment deployment method of mobile nodes, which is based on improved Shuffled Frog Leaping Algorithm(SFLA) is presented from the angle of swarm intelligence algorithm. An optimal deployment model of mobile nodes is set up according to the nodes location information. Simulation results show that the improved SFLA has stronger global convergence ability than Particle Swarm Optimization(PSO), SFLA, Virtual Force Algorithm(VFA) in the application of deployment of mobile nodes, and reduces the wasted energy of the mobile nodes at the same time.
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Computer Engineering. 2012, 38(5): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2012.05.029For the blindness of randomly deploying Wireless Sensor Network(WSN), a strategy is proposed that WSN nodes are deployed following random uniform distribution rule. This paper demonstrates that in the perception area, a large number of sensors with randomly deployment obey Poisson distribution, by establishing the model of WSN node distribution model, find the relationship between the percentage of coverage area and the nodes density of target area. It proposes a scheme that how to estimate the required number of sensor nodes in target area. Experimental results show that the proposed strategy not only guarantees the coverage and connectivity of the WSNs, but also reduces costs effectively.
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Computer Engineering. 2012, 38(5): 102-104,110. https://doi.org/10.3969/j.issn.1000-3428.2012.05.030Aiming at some issues of AOMDV protocol such as low utilization of alternate paths and high frequency of route discovery, this paper proposes a path repair strategy based on bypass establishment named BB-AOMDV. It gets the second hop information of each node to destination by RREQ and RREP packet. Upstream node of breakpoint can build up a bypass path with the downstream node of breakpoint according to these information when path fails. Data can be transmitted normally through this bypass around the breakpoint. Simulation results show that the strategy can improve packet delivery rate and meanwhile effectively reduce the normalized routing overhead and the frequency of route discovery.
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Computer Engineering. 2012, 38(5): 105-107,113. https://doi.org/10.3969/j.issn.1000-3428.2012.05.031Aiming at the problem that non-uniform clustering of LEACH protocol causes the imbalance of energy consumption for network nodes, the notion of considering both the residual energy and distance between the node and the base station in the election of cluster headers is proposed in the paper. Cluster members are determined based on Received Signal Strength Indicator(RSSI), the number of which can not exceed members of the largest number. A method of establishing a hierarchical routing tree considering both the residual energy and distance between the cluster header and the base station between the cluster headers and base station is used for data transmission. Results of simulation indicate that the improved protocol can balance the network load and enhance the network operation cycle.
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Computer Engineering. 2012, 38(5): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2012.05.032This paper proposes a certificateless designated verifier signature scheme in standard model. Combining the certificateless cryptosystem with designated verifier digital signature, with the properties of bilinear pairings to solve the key escrow problem of ID-based cryptography and certificate authorities in traditional public key cryptography. Under the standard model, it proves that it is provable secure against adaptive chosen- message attack under the hardness assumptions of CDH problem and CBDH problem.
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Computer Engineering. 2012, 38(5): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2012.05.033An efficient semi-fragile audio watermark based on KMP is proposed in this paper, which can tolerate general signal processing, detect any spiteful tamper on marked multimedia data, and locate spatial regions within an altered image. Synchronous signals are employed to position the embedded watermark so as to improve the accuracy of watermark extraction. KMP calculation is adopted in searching the synchronous signals to increase efficiency. The algorithm can locate tampered regions without the help from the original watermark. Experimental results show that the proposed algorithm has the advantages such as simple computation complexity, good robustness against shearing attack, and accurate location for tamper.
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Computer Engineering. 2012, 38(5): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2012.05.034According to the features of autonomic intrusion tolerant system compared with ordinary network security system, a survivability evaluating special for autonomic intrusion tolerant system is proposed. Four evaluation indexes such as the secret of data, the integrality of data, the usability of service and autonomic of system are proposed based on the influence of intrusion and the function of autonomic intrusion tolerance. The ways of quantifying the indexes are given according to the features of each index. The survivability situation of autonomic intrusion tolerant system is evaluated dynamically through computing the four evaluation indexes.
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Computer Engineering. 2012, 38(5): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2012.05.035A timestamp-based dynamic remote attestation method oriented to Infrastructure as Services(IaaS) is proposed. This method measures the dynamic cloud nodes’ state in real time, binds the time of measurement with the result, and verifies the current trusted running state of cloud nodes. Based on the method, the attestation methods of cloud node register, remote virtual machine boot and shutdown in IaaS computing environment are designed. These IaaS attestation methods can be used to prove that the user’s virtual machine is booted on a cloud node with trusted running state, and protect the integrity and confidentiality of virtual machine data.
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Computer Engineering. 2012, 38(5): 120-121,125. https://doi.org/10.3969/j.issn.1000-3428.2012.05.036According to definition of algebraic thickness of Boolean functions, the relationship between addition of two Boolean functions and their algebraic thickness is given. Limitation property of upper bound on algebraic thickness is descripted. Meanwhile, the restrictive relationship of algebraic thickness between Boolean function and complement Boolean function is derived. By these results, the upper bounds on algebraic thickness of Boolean functions with small hamming weights and their complement functions are deduced. The probability value of Boolean functions with some algebraic thickness is estimated.
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Computer Engineering. 2012, 38(5): 122-125. https://doi.org/10.3969/j.issn.1000-3428.2012.05.037
This paper proposes an algorithm that can authenticate image and restore tampered region by embedding the authentication watermark and restore watermark. Authentication watermark is embedded in the region of green component by slant transformed. The compressed and slant transformed coefficients as restore watermark are embeded into the least significant bit of each component. If the image is suffered tamper, the last bit of each component can also extract to achieve the image of the self-recovery. Theoretical analysis and experimental results show that under the premise of ensuring transparency and good robustness, the algorithm not only can detect the tampered area but also can restore the tempered region approximation.
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Computer Engineering. 2012, 38(5): 126-128,132. https://doi.org/10.3969/j.issn.1000-3428.2012.05.038The mainstream propagation models can not exactly describe how the bots spread on Internet. To solve this problem, a new propagation model of Botnet on scale-free network is proposed, which considers carefully about the real situation of Internet, especially two key factors including growth and preferential attachment, so it can reflect the scale-free feature of actual Internet. Simulation result indicates that propagation model of Botnet on scale-free network more exactly confirm with the propagation principle and the inflection feature of Bot on actual Internet.
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Computer Engineering. 2012, 38(5): 129-132. https://doi.org/10.3969/j.issn.1000-3428.2012.05.039After analyzing the structure of news Really Simple Syndication(RSS) document, a new information hiding method based on news RSS document is developed. Because the order of the news items does not affect the reading of RSS document, the permutation and combination of tags modules can be used to hide information. Through the rational combination of other two selected information hiding methods based on eXtensible Markkup Language(XML) documents, an information hiding system using multi-methods based on news RSS document is constructed. Experimental results show that three kinds of information hiding methods are not conflict. The system has good performances in capacity, invisibility and robustness.
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Computer Engineering. 2012, 38(5): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2012.05.040The LEGClust algorithm is a new clustering analysis technique, which can effectively find clusters of arbitrary shapes hidden in the data sets. Based on this advantage, this paper applies the algorithm to intrusion detection to establish the intrusion detection model, which can be used to find abnormal data. In the merging process, the LEGClust algorithm tends to merge the abnormal clusters into the normal ones. To solve the problem, it proposes an improved LEGClust algorithm which can significantly improve the performance of intrusion detection. Experimental results on KDDCUP1999 data set verify the effectiveness of the method.
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Computer Engineering. 2012, 38(5): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2012.05.041Due to the constrained resources, Delay Tolerant Network(DTN) nodes hardly resist their selfish behavior. Aiming at this problem, this paper presents a reputation scheme for DTN to minimize the impairment of the selfishness. A protocol of message forwarding and a mechanism of recording are proposed for the detection of selfish behavior. A reputation model is presented to determine the trustworthiness of modes. Experimental results demonstrate the effectiveness of the scheme in the presence of selfish nodes.
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Computer Engineering. 2012, 38(5): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2012.05.042This paper designs exception monitoring model for Linux system. The Warn Notify(WN) protocol is designed for the model. When an exception occurs, the adoption of the protocol can be alarm information to be passed to other multiple hosts. Model uses Principal Component Analysis(PCA) combined with Hotelling’s statistics and Q statistic for anomaly detection. After an exception occurs, the contribution plots getting by principal component method is used to target a specific detection point. Experimental results show that the model has high abnormal monitoring accuracy.
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Computer Engineering. 2012, 38(5): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2012.05.043This paper proposes a trust evaluation model based on intuitionistic fuzzy sets and optimal recommendation. Attributes of inherent trust are described in terms of intuitionistic fuzzy sets. Fuzzy cluster analysis is applied on a set of intuitionistic fuzzy sets of inherent trust for generation trust vector database and storage trust vectors. Calculating formula of recommendation trust is given. Optimal search theory in discrete space is applied for improving the efficiency of calculating recommendation trust degree. Experimental results show that when the network node number is large, this model can get the recommend trust calculation, and have high efficiency evaluation.
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Computer Engineering. 2012, 38(5): 145-148. https://doi.org/10.3969/j.issn.1000-3428.2012.05.044Aiming at the limitation on the old tunnel in system of distributed honeypot based on Honeyd, the ping-pong effect occurres. This paper proposes an improved tunnel-routing method of Honeyd. It studies the Generic Routing Encapsulation(GRE) communication principle of tunnel, and analyzes the causes of the table tennis effect. On the basis of it, the paper improves the expanding IP protocol, routing table and data packet processing flow. Experimental results show that using the method to improving the GRE tunnel can keep the original network topology, and has no influence on network throughput rate and CPU occupancy rate.
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Computer Engineering. 2012, 38(5): 149-151,157. https://doi.org/10.3969/j.issn.1000-3428.2012.05.045According to the space communications’ especial environment such as the exposed channel, the large coverage area and the limited bandwidth resources, this paper analyzes and compares the advantages and disadvantages of two types of conventional data encryption algorithm, symmetric encryption and asymmetric encryption. After mixing the two types of algorithms and making a brief analysis of the feasibility, a data protection strategy is designed to ensure that the space data can be transmitted in security. Theoretical analysis and simulation results show that the proposed strategy is fairly practical.
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Computer Engineering. 2012, 38(5): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2012.05.046Recoding k and direct computing kp by introducing the balanced ternary to scalar multiplication can improve its efficiency. This paper gives an algorithm which recodes k as balanced ternary string, and proposes a balanced ternary algorithm to scalar multiplication. In this case, the average efficiency is improved 5.4% relative to the binary algorithm. When precomputation is used, the average efficiency is improved 73.18% and 15.58% relative to the algorithm which uses binary and binary precomputation, and the accounts which need to store is declined observably.
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Computer Engineering. 2012, 38(5): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2012.05.047By using the Juels model, a formal proof is given that the output of the Rhee protocol preserves privacy, denotes as ind-privacy. The accurate security boundary of the Rhee protocol is computed rigorously. The privacy of protocol is reduced tightly to assumption that the Random Oracle is existed by utilizing the Game-based technique and the Shoup lemma which can distinguish adjacent game with the negligible probability of upper bound. This technique is a powerful tool for analyzing and solving the privacy problem of Radio Frequency Identification(RFID)system, and provides an effective and universal solution in the future.
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Computer Engineering. 2012, 38(5): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2012.05.048Aiming at the problems that do not balance the node cost and the low filter probability of the traditional methods, this paper proposes an improved method of false data filtering. In this method, the cluster structure in Wireless Sensor Networks(WSN) is established by the unbalanced energy of nodes, and through computing the load of nodes and distributing the key, the false data is filtered. Simulation experimental results show that the proposed method can balance the cost of nodes, and improve the probability of false data filtering significantly.
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Computer Engineering. 2012, 38(5): 161-162,166. https://doi.org/10.3969/j.issn.1000-3428.2012.05.049This paper presents a triple stream Dynamic Bayesian Networks(DBN) model(T_AsyDBN) for audio visual emotion recognition, in which the two audio streams are synchronous at the state level, while they are asynchronous with the visual stream within controllable constraints. MFCC features and local prosodic features are extracted as audio features, while dimensional geometric features as well facial action units’ coefficients are extracted as visual features. Emotion recognition experiments show that by adjusting the asynchrony % to 63.71%.constraint, T_AsyDBN performs better than the two stream audio visual DBN model(Asy_DBN), with average recognition rate improves from 52.14
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Computer Engineering. 2012, 38(5): 163-166. https://doi.org/10.3969/j.issn.1000-3428.2012.05.050Aiming at feature selection and parameter optimization problem of classifier based on Support Vector Machine(SVM), one kind of combination optimization for feature selection and parameter is presented based on chaotic genetic algorithm of mutative scale. The method of chromosome coding and decoding is presented. Initialization population is produced by using chaos ergodicity. A modified crossover operator and dynamic reducing searching space is used for further optimization. This method is applied to fault classifier combination optimization of shortwave-control-equipment. Experimental results assess effectiveness on finding optimal solution of the proposed approach.
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Computer Engineering. 2012, 38(5): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2012.05.051One-technology do not solve multi-class classification problem, on the basis of this, a basic probability output distribution method based on One-Against-All(OAA) Support Vector Machine(SVM) is proposed, a multi-class model based on Support Vector Machine(SVM) probability output and evidence theory is put forward by integrating one-against-all multi-class SVM with max-entropy D-S theory, . Simulations results on three datasets of UCI repository show that the method has higher classification precision than hard output method OAA and OAO.
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Computer Engineering. 2012, 38(5): 170-172,175. https://doi.org/10.3969/j.issn.1000-3428.2012.05.052Due to the shortcomings of current semantic similarity metric not fully using the semantic information of ontology and its complex computation, this paper proposes a new semantic similarity metric calculation method based on the feature of concept, which makes full use of the information of ontology structure. It expresses each concept as a set of features according to the hierarchy of ontology, and introduces a width influencing factor as the coefficient of each feature. It obtains the semantic similarity through calculating the similarity between two sets. It introduces a depth influencing factor, and amends the semantic metric to a more understandable form. Theoretical analysis and experimental results show that the metric is simple, and the results are close to human judgment.
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Computer Engineering. 2012, 38(5): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2012.05.053This paper proposes a shadow removal algorithm for moving pedestrian based on weak thresholds segmentation. The thresholds for segmentation are classified into weak and strong. The foreground is extracted by Gaussian Mixture Model(GMM). The weak thresholds are applied in color space and gradient space respectively to get partial objects, which are merged next. After the neighbour fixing, the complete object with no shadow pixels is obtained. Experimental results prove the validity of the algorithm.
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Computer Engineering. 2012, 38(5): 176-178,182. https://doi.org/10.3969/j.issn.1000-3428.2012.05.054As the problems of estimation accuracy and particles degradation exist in the Particle Filtering(PF) algorithm, an improved PF algorithm is proposed. This algorithm which is based on PF uses the Unscented Kalman Filtering(UKF) to generate the proposal distribution so as to improve the filtering effect. It synchronizes the standard Markov Chain Monte Carlo(MCMC) sampling method and the unscented PF, which can reduce the effect that the traditional PF does not consider the current measurement, and makes the particles more diversification. Simulation results demonstrate that the algorithm has more significant advantages in tracking accuracy and filtering effect than other traditional PF algorithms.
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Computer Engineering. 2012, 38(5): 179-182. https://doi.org/10.3969/j.issn.1000-3428.2012.05.055The detection speed of traditional pedestrian detection method based on Histograms of Oriented Gradient(HOG) feature is slow. In order to detect pedestrian faster, a pedestrian detection method based on edge symmetry and HOG is proposed. Symmetric difference is used to extract the vertical edge of the input window. Candidate pedestrians can be detected rapidly according to the symmetry of the vertical edge. Candidate pedestrians are validated by using HOG feature and linear Support Vector Machine(SVM). Experimental results show that the proposed method can increase the detection speed while maintaining the comparable detection rate to the traditional method based on HOG feature.
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Computer Engineering. 2012, 38(5): 183-185,188. https://doi.org/10.3969/j.issn.1000-3428.2012.05.056According to the requirements of vehicle classification, this paper presents a vehicle type recognition algorithm based on error ellipse. It uses background differential method to remove the uncorrelated background of vehicle image, so to get the target image. Vehicle recognition and contour extraction is done by image analysis. A 2D coordinate uncorrelated variance matrix is got by translating, rotating and zoom operating the vehicle outlines. The uncorrelated variance matrix is used to compare with the vehicle classification template in advance and a vehicle is classified to the right type. Experimental results show that the algorithm can obtain good classification results, and meet the requirement of real-time.
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Computer Engineering. 2012, 38(5): 186-188. https://doi.org/10.3969/j.issn.1000-3428.2012.05.057
It is not enough that only using a dimension analysis method for non-stable signal in a stable distribution noise. A novel wavelet time-frequency analysis method of fractional lower-order a stable distribution is proposed in this paper based on conventional wavelet, which includes the idea combining traditional wavelet and spectrum analysis. Simulations show that the proposed method has more excellent performance than conventional wavelet in time-frequency analyzing of a stable distribution process.
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Computer Engineering. 2012, 38(5): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2012.05.058The characteristics of Tibetan are analyzed in this paper. The framework of auto speech recognition of Lhasa dialect is designed. Several feasible units for acoustic models are analyzed. Contextual continuous Hidden Markov Model(HMM) models based on phonemes and semi-syllables are established and trained on Hidden Markov Model Toolkit(HTK) platform respectively and large-vocabulary continuous speech recognition of Lhasa Tibetan is implemented. Experimental results show that Word Error Rate(WER) is 7.8% in the best case.
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Computer Engineering. 2012, 38(5): 192-195. https://doi.org/10.3969/j.issn.1000-3428.2012.05.059This paper designs and establishes flying-trace models separately in two-dimension and three-dimension ways after analyzing the flying-trace issue on Unmanned Aerial Vehicle(UAV), and obtains the shortest flying-trace on the premise of safety. A basic assumption is made, the calculation course of targets detection probability and the planning process of the shortest flying-trace are given. Through designing the concrete simulation condition, the flying-trace problems in different dimensions are solved and analyzed which verifies the rationality of the model.
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Computer Engineering. 2012, 38(5): 196-198,201. https://doi.org/10.3969/j.issn.1000-3428.2012.05.060Facing an uncertain, nonlinear, dynamic and complicated system, gas load forecasting generally can not get a sufficient accuracy result when using traditional forecast model. This paper proposes a wavelet v-Support Vector Machine(SVM) compound model, wavelet analysis extracting the feature of gas load, and PSO determining the parameter of Wv-SVM model, solving nonlinear regression and time series problems. Experimental results show that the proposed model outperforms the back propagation neural network and traditional Gauss SVM model.
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Computer Engineering. 2012, 38(5): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2012.05.061Artificial Neural Network(ANN) has difficulty in expression of the temporal accumulation in the time series prediction. A prediction method which uses the Process Neural Networks(PNN) is presented. The algorithm of quantum particle swarm which has double chains structure is used to train the PNN. The effectiveness of the method and training algorithm are proved by the Mackey-Glass time series prediction. Simulation result shows that the mean-square error about this method is reduced one order of magnitude compared with ANN.
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Computer Engineering. 2012, 38(5): 202-204,207. https://doi.org/10.3969/j.issn.1000-3428.2012.05.062In order to solve problem of parameter estimation, an Differential Evolution algorithm with Control Parameter Adaptation and Strategy Adaptation(DE-CPASA) is introduced. In DE-CPASA, differential evolution operator is used to search the optimization results of problems, and Gaussian distribution is employed to implement the adaptive control parameters. The strategy adaptation is achieved by evaluation of value of fitness function. Simulation test results show that DE-CPASA can obtain a higher precision solution and has fast convergence. DE-CPASA is employed to estimate the kinetic parameters of Hg oxidation, and a good optimization result is obtained.
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Computer Engineering. 2012, 38(5): 205-207. https://doi.org/10.3969/j.issn.1000-3428.2012.05.063To avoid the subjectivity and the inefficiency in traditional metal industrial component detection by means of X-ray image, an intelligent detection method based on Gaussian Mixture Model(GMM) is put forward. Image sequence of the same component is learned online, and each pixel is composed of multiple Gaussian distribution. During ordinary process, the pixels are classified to different patterns by the learned Gaussian. During ordinary process, the pixels are classified to different patterns by the learned Gaussian distribution, and the pixels not belonging to any existed Gaussian distribution are regarded as perspective objects(damage points). The overall damage region is confirmed by connecting damage sector based on seed growth method. Experimental results show the method can locate the damage position in a component accurately and automatically. Furthermore, detection efficiency is increased obviously.
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Computer Engineering. 2012, 38(5): 208-210. https://doi.org/10.3969/j.issn.1000-3428.2012.05.064According to the traditional arithmetic in skin color detection which can not attain high precision detection and rapid rate transact. The paper proposes an arithmetic based on Fuzzy Cognitive Map(FCM) for detection skin color area on compressed domain. Color and texture features of the image blocks are extracted from the entropy decoded Discrete Cosine Transform(DCT) coefficients. The FCM is applied to set up the skin color color model to describe the relationship between the image block features and the skin color detection results, and the initial skin color image blocks are detected based on the model. Experimental results show that, compared with the traditional methods, it has higher accuracy and shorter detection time.
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Computer Engineering. 2012, 38(5): 211-212,215. https://doi.org/10.3969/j.issn.1000-3428.2012.05.065Chan-Vese(C-V) model is computationally expensive and sensitive to initialization. In order to address these problems, a new active contour model combined with region gradient is proposed, which uses the gradient information in the interior of contour and the intensity information in the exterior of contour. Experimental results show that the proposed model can more quickly segment multi-phase images and allows more flexible initialization compared with the multi-phase CV model.
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Computer Engineering. 2012, 38(5): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2012.05.066According to the Gibbs effect of image denoising in real wavelet transform domain, this paper proposes a Hidden Markov Tree(HMT) model based on Quaternion Wavelet Transform(QWT). The QWT theory and HMT are combined in this model which effective reflect the correlation between wavelet coefficient and capture the neighborhood statistical characteristics of wavelet coefficients. Experimental results show that the model both in Peak Signal to Noise Ratio(PSNR) and in the visual effect are better than many classic denoising method.
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Computer Engineering. 2012, 38(5): 216-217,220. https://doi.org/10.3969/j.issn.1000-3428.2012.05.067This paper proposes a medical image region fusion algorithm based on multi-resolution. The source images are decomposed into multi-resolution representations. Considering the influences of the neighborhood coefficients, a local maximum selection rule is proposed to fuse the high frequency bands. The Fuzzy C-means(FCM) algorithm is used to segment the low frequency band with largest entropy into regions which are mapped to the other low frequency bands, then the regions are fused using the EM fusion algorithm. The fused image is obtained by reconstructing the coefficients. Experimental results show that the proposed algorithm has good fusion quality and high efficiency.
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Computer Engineering. 2012, 38(5): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2012.05.068To avoid human supervising in the image matting process, this paper proposes an unsupervised image matting approach based on saliency. A saliency map is extracted from an image, and more accurate information is extracted from the map by block merging and filtering methods. The image is divided into multiple levels for multi-resolution matting and then the foreground object is matted out on the basis of the processed saliency information. Experimental results show that the approach is better than the unsupervised spectral matting method in both computing speed and matting effect.
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Computer Engineering. 2012, 38(5): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2012.05.069Aiming at multi-spectral image fusion problem, this paper proposes an improved Wavelet-based Contourlet Transform(WBCT) by adopting lifting wavelet transform instead of traditional wavelet transform. Multi-scale decomposition is performed on source images through the improved method to get high-frequency and low-frequency component, which are then processed by different fusion rules and the fused coefficients are obtained. And the inverse improved WBCT is utilized to obtain fused image. Experimental results show that compared with Contourlet transform and lifting wavelet transform, improved method has better integration effect.
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Computer Engineering. 2012, 38(5): 224-226,229. https://doi.org/10.3969/j.issn.1000-3428.2012.05.070Aiming at 3D reconstruction problem of a single image which is self-calibrated, this paper proposes a method based on silhouette outline. It uses angled plane mirror system to take a picture. After tracking the edge of the target object in the image, the closed contours are got. A pair of outlines of the silhouette which obey the plane mirror imaging principle are used to get vanishing points, so that camera parameters can be calculated by analyzing the constraints between vanishing points. The 3D model of the target object is obtained by using the camera parameters. Experimental results show that the method can realize 3D reconstruction of the target object distinctly and efficiently.
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Computer Engineering. 2012, 38(5): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2012.05.071In order to suppress pseudo-Gibbs phenomenon, improve Peak Signal to Noise Ratio(PSNR) in the process of image denoising, this paper proposes a remote sensing image denoising algorithm based on Nonsubsampled Contourlet Transform(NSCT) threshold shrinkage approach. It uses the correlation intra-scale in NeighShrink denoising algorithm and the correlation among scale in BiShink denoising algorithm to deal with the noise image. By using the shift invariance of NSCT, it suppresses the pseudo-Gibbs phenomenon. Experimental results show that the proposed algorithm gets better results than other methods mentioned in the area of PSNR and visual effect.
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Computer Engineering. 2012, 38(5): 230-232,246. https://doi.org/10.3969/j.issn.1000-3428.2012.05.072Aiming at the weaknesses of software-based scheduler such as low speed, big jitter and low efficiency, this paper proposes a general scheduling method based on hardware. Taking the applications in real-time operating system and in Foundation Fieldbus(FF) scheduler as examples, the design methods and working principles are discussed, and software-based and hardware-based schedulers’ efficiency are compared, whose result proves that hardware-based scheduler is more efficient in absolute speed as well as in jitter erasing.
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Computer Engineering. 2012, 38(5): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2012.05.073This paper extracts 20 characteristic parameters of time domain and frequency domain as data sample, chooses Radial Basis function(RBF) and related parameters which are suitable for rotating machinery vibration signal, and constructs a one-against-all Support Vector Machine(SVM) multi-class classifier to identify health status of rolling bearing. Compared with Back-propagation(BP) neural network, the SVM classifier with the vibration features of rolling bearing. Experimental results indicate that the SVM classifier can better solve the problem of small sample, is superior to the BP neural network in the training time and recognition accuracy.
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Computer Engineering. 2012, 38(5): 236-239. https://doi.org/10.3969/j.issn.1000-3428.2012.05.074This paper proposes a radioresistance placement algorithm for Field Programmable Gate Array(FPGA) based on Static Random Access Memory(SRAM) on the base of academic Versatile Placement and Routing(VPR) tool. To achieve the goal of mitigating the number of the Single Event Upset(SEU) sensitive points, the cause of the soft error is analyzed and the positions of the programmable blocks are optimized by placement algorithm. The algorithm tests in a fault injection system which simulates the high radiation environment. Experimental results show that the algorithm can effectively reduce the SEU effects of SRAM-based FPGA in high radiation environment, improving the fault tolerance ability of the circuits implemented in the FPGA, and it does not need to add the extra design and hardware cost.
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Computer Engineering. 2012, 38(5): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2012.05.075On the basis of Transport-triggered Architecture(TTA), this paper designs a configurable processor and T*Core processor. Using this processor in embedded Field Programmable Gate Array(FPGA) platform for System on Chip(SoC) implementation. It can handle large amounts of data intensive computing. Application result shows that this design can improve the data processing of real-time, reduce the consumption of the hardware resources, and reach astronomical image processing demand.
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Computer Engineering. 2012, 38(5): 243-246. https://doi.org/10.3969/j.issn.1000-3428.2012.05.076In order to improve real-time, stability and design flexibility of target detection and tracking in intelligent video surveillance, a real- time single target tracking system with alarming function applied to static background based on Field Programmable Gate Array(FPGA) is designed. Frame difference combined with morphology is used to reduce the influence of change of environment on the system, and multi-point positioning location algorithm is used to achieve the purpose of target tracking. Simulation results show that the system runs quickly and stably, the target within the camera view can be real-time tracked when the target is not moving, and the system is robust.
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Computer Engineering. 2012, 38(5): 247-250,254. https://doi.org/10.3969/j.issn.1000-3428.2012.05.077According to the low level of automation for the conventional electric power communication resource management, this paper combines the Internet Of Things(IOT) technology with resource management, taking on the research of the electric power communication network resources life cycle management system based on the IOT. It describes the system hardware and software architecture system, and probes into the method and key technology of Electronic Product Code(EPC) reading and writing and database synchronization on the system platform. A power company's specific application examples validate the feasibility and practicality of the system platform to achieve intensive, fine, digital electric power communication resource management mode.
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Computer Engineering. 2012, 38(5): 251-254. https://doi.org/10.3969/j.issn.1000-3428.2012.05.078To meet the requirement of a series of complex data processing in modern Digital Signal Processor(DSP), a 64 bit floating-point coprocessor specially for floating-point complex vector arithmetic is proposed with the logic resources and IP library of ARM9 and the Field Programmable Gate Array(FPGA) chip from Xilinx. The algorithm of related floating-point arithmetic could be revised. Results of the test on the hardware simulation platform show that the floating-point complex vector arithmetic performance is greatly improved by the coprocessor.
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Computer Engineering. 2012, 38(5): 255-258. https://doi.org/10.3969/j.issn.1000-3428.2012.05.079Based on how to extend Geographical Information System(GIS) services to the wheat nitrogen fertilizer fertilization on the field, and apply GIS to serve the ordinary mobile users of agricultural production, this paper, by integrating GIS services, Global Positioning System(GPS), wireless communications technology, according to the wheat nitrogen fertilizer fertilization recommendation model and using Java language as a platform, discusses how to establish a nitrogen fertilizer fertilization recommendation system of wheat based on GIS wireless service, and realizes the system which can provide nitrogen fertilizer fertilization recommendation consultation of wheat at anytime, at anywhere. Application result shows that this system runs stably and has good using effect.
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Computer Engineering. 2012, 38(5): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2012.05.080Operation System(OS) for multi-processor is a key issue to manage the resource generally. This paper applies the asymmetric multi- processing mode to design a distributed operating system for a Network on Chip(NoC)-based Multi-processor System-on-Chip(MPSoC). The nodes, divided into control node and operation nodes, use MPSoC Message Passing Interface(MMPI) to communicate with each other. An embedded Linux which runs on the control node, uses statistics pool to collect system resources information and schedules the parallel applications when they execute. The μC/OS on the operation nodes uses virtual memory to create, load and execute MPI tasks assigned to each operation node. Test result shows that this design manages the MPSoC effectively.
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Computer Engineering. 2012, 38(5): 262-265. https://doi.org/10.3969/j.issn.1000-3428.2012.05.081Since the usual procedure of electronic forensic based on one-to-one cloning mode is too complicated and lack of efficiency, this paper proposes a network multiple hard disk duplicator for electronic forensics. It uses the iSCSI protocol to backup the data of many remote hard disk, and saves the data image to high capacity torage device. Identification terminal uses high-speed storage network to do data recovery identification and virtual analysis by the image files. Experimental results show that the duplicator has fast and high speed to obtain the evidence, and copy rate is about 6.5 GB/min.
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Computer Engineering. 2012, 38(5): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2012.05.082In Wireless Sensor Network(WSN) testbed, burning source code manually on sensor nodes brings many disadvantages, such as spending much time, bringing about human errors. Toward these problems, this paper proposes an automatic burning method, which can be suitable for the larger scale WSN testbed. The node mirror program is transferred through TCP/IP technology in the LAN and the node program is burning. On the PC side, multiple nodes program are simultaneous burning by the way of multi-threaded. Experimental results on the existing test bed verify the feasibility of this method.
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Computer Engineering. 2012, 38(5): 269-272,275. https://doi.org/10.3969/j.issn.1000-3428.2012.05.083This paper focuses on the tie-in-sale characteristic of fast fashion product in the degenerating period of e-commerce retailing. A non-liner mixed integer programming model for multi-product assembling and order taken by customer is proposed aiming at maximizing the profit of logistics distribution network for fast fashion product. By introducing the assembling parameter and the study of assembling solution, the integer optimization can be realized in different assembling rate. The model is solved by using simulated annealing algorithm, and results illustrate that the enhancement of the assembling rate not only can increase the gross sales, but also can decline the logistics cost.
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Computer Engineering. 2012, 38(5): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2012.05.084Aimingat the problem of 3D reconstruction method high computation complexity, 3D reconstruction method based on Virtual Height Projection Line(VHPL) is proposed. Scene is divided into grids where Virtual Height Lines(VHLs) are introduced, and each projection lines(PL), generated by projecting VHL into 2D image, whose correspondence is found to obtain the 3D data, the proposed method can express the scene basically. The error is analyzed, and the compensation is proposed combined with the intrinsic and extrinsic camera parameters. Experiments show the validity of the method.
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Computer Engineering. 2012, 38(5): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2012.05.085Aiming at the characteristics of the current higher education, this paper designs and develops a blending learning supporting system, which can integrate the advantages of E-learning and class-learning, and gives the design of its architecture, concepte model and database. The system not only supports teacher’s teaching process, but also benefits for the training of independent learning and innovative ability of students. It can supply the most suitable teaching strategy for student according to his interests and the form of instructional resource. The learning efficiency can achieve optimization.
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Computer Engineering. 2012, 38(5): 279-280,284. https://doi.org/10.3969/j.issn.1000-3428.2012.05.086In order to reduce the workload of daily Word report generation, this paper presents a scalable method of automated Word report generation based on dynamic Web pages. The symbols encapsulated from data processing methods are inserted into Word document in order to customize the report template, which is converted to ASPX Web pages. The corresponding data processing methods are invoked to input or retrieve information according to the user operation. The symbols are replaced by the information in order to generate the final report. Application results demonstrate that the method can improve the efficiency of Word report generation.
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Computer Engineering. 2012, 38(5): 281-284. https://doi.org/10.3969/j.issn.1000-3428.2012.05.087Usage Control(UCON) model can resolve dynamic authorization of access control in pervasive computing environment, but it does not consider context information. For this reason, this paper presents a Context-based Usage Control(CUCON) model in pervasive computing environment. A context information is added into usage decision factor, it includes time, location and environment. And the core rules are defined by Temporal Logic of Action(TLA). Through the example of pervasive computing intelligent classroom, the effectiveness of this model is proved.
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Computer Engineering. 2012, 38(5): 285-287,290. https://doi.org/10.3969/j.issn.1000-3428.2012.05.088By analyzing the problem of logistics, this paper proposes a way of dispatching material on the basis of two-layer distribution center. When dispatching the materials, the side of supplier has to pass through two layers of distribution center to reach the side of demander, otherwise it will be punished. On the basis of establishing the model of four-layer logistics network, which includes the sides of supplier and demander, also two layers of distribution center, this paper uses the Dijkstra algorithm to obtain the shortest transport distance between the point of supplier point and the point of demander, and conversion into the balance chart of supply and demand, then it makes use of algorithm which combines the Tabular method and save-mileage method to solve the model of four-layer logistics network. Experimental results show that the algorithm can guarantee the least total cost of transportation. At the same time, it can effectively reduce the number of vehicle schedule in the process of delivery.
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Computer Engineering. 2012, 38(5): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2012.05.089To solve the problem of low precision rate in the traditional automated assessment of subjective tests, this paper improves a method to estimate subject tests. Words of semantic similarity computing are based on “TongYiCi CiLin”. Bipartite graph is constructed according to calculating similarity of words in standard answer and student’s answer. And the biggest matching algorithm is used to compute similarity between texts. Experimental results show that precision and recall rate are greatly improved.
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Computer Engineering. 2012, 38(5): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2012.05.090Traditional spectral subtraction based on Short Time Fourier Transform(STFT) is a kind method of single resolution, and has large variance. In order to solve this problem, this paper proposes a speech enhancement algorithm of multiple window spectrum estimation under wavelet packet decomposition. It decomposes the noisy speech signal into different frequency band under wavelet packet, does take the spectral subtraction operation of multiple window under different frequency, and does the wavelet packet reconstruction to get denoising speech signal. Simulation result shows that this algorithm can improve the speech Signal Noise Ratio(SNR) with noise, and improve the speech distortion degree.
2024
Volume 50 No 4
Volume 50 No 4
(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