15 September 2013, Volume 39 Issue 9
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Computer Engineering. 2013, 39(9): 1-5. https://doi.org/10.3969/j.issn.1000-3428.2013.09.001
To solve the problem that current flash-based database index mechanisms do not have both high update and query performance, this paper proposes an Efficient B+ Tree Indexing Mechanism(EBTIM) for flash-based database. EBTIM updates the index through log method, and a buffer is designed to ensure that loges are efficiently written to flash. Due to low index query efficiency of log update method, a node-log map table is designed to avoid global search log for index. Meanwhile at the right time loges are integrated into the B+ tree logic node to optimize the index query. Furthermore, a node cache is designed to improve the index query efficiency. A Experi- mental result show that EBTIM improves the update efficiency by 51% and query efficiency by 2.3 times compared to BFTL, and it has the same query efficiency of B+ tree index mechanism based on Nand Flash Translation Layer(NFTL), but it improves the update efficiency by 2.4 times compared to NFTL.
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Computer Engineering. 2013, 39(9): 6-11. https://doi.org/10.3969/j.issn.1000-3428.2013.09.002
In order to mine the potential vulnerabilities in Diameter protocol dialog flow of IP Multimedia Subsystem(IMS) abnormal scenarios, this paper proposes a leak mining method of Diameter protocol flow based on the Genetic Algorithm(GA). The method makes a given scenario by mutating network configuration, user state, and servers’ state. And generates multi-dimension fuzziness test data for the scenario using GA. This paper makes decisions that whether there are related vulnerabilities by watching the network’s response to the test messages. Simulation experimental result shows that the test messages’ generating method both ensures the messages’ randomness and improves the effectiveness, it can mine the vulnerabilities of Diameter protocol flow effectively.
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Computer Engineering. 2013, 39(9): 12-14,19. https://doi.org/10.3969/j.issn.1000-3428.2013.09.003
In order to improve the quality of the color image edge information, a new color edge detection alogortihm is proposed based on HSI color space which reflects the feature of human vision. A new component V combining the H, S, I components is used to improve the effectiveness of detection. The measurement of color distance is improved according to the correlative to H and S component. It uses edge growing method to get the edge images of the four components. Taking advantage of data fusion technique, the four edge images are combined into an edge image of the color image. Experimental results show that this algorithm can effectively eliminate noise effects and improve the accuracy of the edge information.
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Computer Engineering. 2013, 39(9): 15-19. https://doi.org/10.3969/j.issn.1000-3428.2013.09.004
Due to lack of some hardware functions, Software Pipelining(SWP) on Open64 can not work on X86 processors. To solve this problem, this paper proposes an Open64 software pipelining framework. This framework can make SWP work well on X86 processors by software implementation of some processor features, by some loop filtering and by rewriting the register allocation code for the lack of circulating register file to achieve the purpose of the use of general purpose registers and adding the modulo variable expansion modulo to ensure the correctness. Experimental results show that this framework can achieve an average of 9% performance improvement.
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Computer Engineering. 2013, 39(9): 20-24,29. https://doi.org/10.3969/j.issn.1000-3428.2013.09.005
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Computer Engineering. 2013, 39(9): 25-29. https://doi.org/10.3969/j.issn.1000-3428.2013.09.006
For the demand for multiple application environment of high-speed photography, this paper proposes a design method of area interline Charge Coupled Device(CCD) multiple working modes. After introducing the working principle of area CCD KAI-0340D, combining with the character of its internal structure and dual channel data transmission mode, the timing sequence of the sensor is analysed. The four resolution working modes are achieved by changing the three level signals and the FD signals in different regions. Different working modes are divided into different field modes and stored in AD9979. By changing the combination of different field modes in AD9979, the timing sequences of different working modes are realized. Experimental results show that the designed timing sequence of four kinds resolution works well, basically meet multi-application requirements for high-speed photography.
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Computer Engineering. 2013, 39(9): 30-33,44. https://doi.org/10.3969/j.issn.1000-3428.2013.09.007
In order to assess the image degraded quality problem of a video, an objective video quality assessment method based on corner feature detection is proposed. By simulating the test images degraded in a real environment, and simulated images are generated. Then the number of corner in different corner detection parameters for test images and simulated images are computed by binary edge image to curvature. The best test image and corner detection parameters for a real environment can be obtained. Furthermore, the video quality is divided into several grades by the number of the detected corner. Then the number of corner for the test image detected in a real environment is regarded as the discriminant basis of the video quality assessment. Simulations are carried out by Matlab, the results show that the result of proposed method is keeping with subjective evaluation results, it is efficient.
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Computer Engineering. 2013, 39(9): 34-38. https://doi.org/10.3969/j.issn.1000-3428.2013.09.008
Compared with traditional methods of traffic information data collection, Radio Frequency Identification(RFID) system provides a better solution for the real-time condition. However, the collected data is discrete not only on temporal, but also on spatial. Though the RFID system, this paper aggregates the traffic data collected by Internet of Vehicles(IoV) using the road section as a minimum compartment, and obtains the driving models for various vehicles based on the statistics of vehicle fuel consumption on highway. Moreover, it proposes Fuel Consumption algorithm based on the Internet of Vehicle(FCIV), and uses visual representation technology, which directly reveals the change of the fuel consumption of every road section in highway, and the variation of the fuel consumption in spatial compartments by days of the week and hours of the day.
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Computer Engineering. 2013, 39(9): 39-44. https://doi.org/10.3969/j.issn.1000-3428.2013.09.009The deviation of the DV-Distance positioning algorithm in perimeter intrusion detection is too large. Aiming at this problem, this paper improves DV-Distance(IDV-Distance) algorithm and proposes a node positioning algorithm which is suitable for ribbon Wireless Sensor Network(WSN). This algorithm gets the cumulative hop distance measured by RSSI method, and corrects it based on the ribbon WSN topology characteristics. It preliminary estimates node position using the maximum likelihood method, and improves the node positioning accuracy by steepest descent algorithm. Experimental results show that, compared with the classical DV-Distance algorithm and two kinds of improved DV-Distance algorithms in ribbon WSN, this algorithm has higher accuracy.
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Computer Engineering. 2013, 39(9): 45-48. https://doi.org/10.3969/j.issn.1000-3428.2013.09.010
Current research of Internet of Things(IoTs) takes the overall system as a whole, which is complicate to design and verify. Aiming at this problem, a complex IoTs which is modeled as a hybrid system, is divided into several sub systems in this paper. A method is proposed which verifies the whole IoTs by verifying and compositing these sub systems independently. Intelligent transportation system is taken as example, and analysis result shows that this method can reduce the complexity of the system, increase the degree of modularity, and ensures the modularity and scalability of IoTs.
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Computer Engineering. 2013, 39(9): 49-51,58. https://doi.org/10.3969/j.issn.1000-3428.2013.09.011This paper introduces Radio Frequency Identification(RFID) anti-collision algorithm based on B+ tree, and analyses the influence of different splitting order to recognition efficiency. It finds that when the splitting order increased, the collision slot is reduced but the idle slot is increased, which in turn reduces the efficiency of the algorithm. Aimming at this problem, this paper proposes an improved algorithm. The improved algorithm reduces the collision slot and idle slot simultaneously by modifying the execution procedure and controlling the splitting dynamically. It considers the limitation of resources on the tag and does not increase the hardware configuration. Simulation result demonstrates that this improved algorithm can improve the efficiency of system recognition under the circumstances of a large number of tags, while keep the communication cost low.
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Computer Engineering. 2013, 39(9): 52-58. https://doi.org/10.3969/j.issn.1000-3428.2013.09.012In data fusion based on Mobile Agent(MA) in Wireless Sensor Network(WSN), the order and number of nodes on the route traversed by a MA determine the energy consumption and hence, which has a significant impact on the overall performance of the whole system. So this paper proposes a Redundancy Based Mobile Agent(RBMA) algorithm, which brings in redundancy parameter together with residual energy parameter and the shortest distance parameter. Methods are adopted to eliminate redundant nodes, create and optimize MA itinerary includes threshold processing, Kruskal method and improved post-order transversal. Simulation result shows that, RBMA algorithm decreases data delay, and consumes less energy than Genetic Algorithm(GA) and Near-optimal Itinerary Design(NOID) algorithm. It can prolong the network lifetime.
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Computer Engineering. 2013, 39(9): 59-63. https://doi.org/10.3969/j.issn.1000-3428.2013.09.013Aiming at the phenomenon of coverage holes because of energy depletion and random nodes deployment in Wireless Sensor Network(WSN), a strategy for hole recoverage based on best candidate node is proposed. This strategy increases redundant nodes which hibernate as the candidate nodes in the target area, and selects the best candidate node from redundant nodes to patch the hole based on repaired position. If it is in the controllable range that the redundant node will be actived as the best candidate node and be moved based on repaired position to patch the hole. Otherwise, the second generation mobile node will be used to patch the hole. Experimental results show that the strategy is not limited by coverage hole shape, and can reduce the extra second generation mobile node number in the premise of ensuring the network coverage of no less than 90%, which improves the performance of WSN significantly.
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Computer Engineering. 2013, 39(9): 64-68. https://doi.org/10.3969/j.issn.1000-3428.2013.09.014There are many security problems in Wireless Sensor Network(WSN) on the base station model. These security problems include the low efficiency of error verification, correction and removal. Meanwhile, the information authentication has poor credibility, low communication security, and heavily depends on resource dependence. To improve the security of such network, an grouping and layered key management strategy in WSN based on Exclusion Basis System(EBS) which named EBS-GL is proposed. This model employs technologies such as network decoupling, a novel grouping and layered information encryption algorithm, the information integrity authentication mechanism, and the strategy of removing singularity. Simulation results prove that this model has stronger abilities of error verification, correction and removal of base stations than JERT strategy.
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Computer Engineering. 2013, 39(9): 69-73. https://doi.org/10.3969/j.issn.1000-3428.2013.09.015Cluster-based topology control method in Wireless Sensor Network(WSN) does not consider the nodes’ residual energy reasonably, which may make the cluster head chosen die soon. And it does not take the number of cluster members into account in the clustering process, which may result in the overloading of the cluster head. Aiming at these problems, in this paper, an adaptive topology control method based on energy and balanced clustering is proposed. The cluster heads’ selection of this method considers the residual energy of nodes, at the same time, the method adopts the idea of equalization to form the cluster members adaptively. Simulation results show that the method can reduce the nodes’ death rate effectively, prolong the network lifetime and improve the service performance.
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Computer Engineering. 2013, 39(9): 74-79. https://doi.org/10.3969/j.issn.1000-3428.2013.09.016The adaptive processing of non-stop coming Ad Hoc queries over data stream concerns much on the fast on-the-fly plan updating and migration. Existing methods implementing the shifting from old plan to new plan need amounts of work to move the state maintained in operators’ sliding time window leading to large time delay. This paper proposes a highly efficient Ad Hoc query processing algorithm called AQU, which can compute the best incremental updating based on the summary view of data stream characteristics and a slef-defined model, handle the newly arriving Ad Hoc queries. This algorithm reduces the time shifting from old plan to new one and is also adaptive to non-top incoming queries. Experiments on the high way data generated by data stream benchmark Linear Road shows the efficiency of this algorithm.
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Computer Engineering. 2013, 39(9): 80-83. https://doi.org/10.3969/j.issn.1000-3428.2013.09.017In order to improve the efficiency of clustering algorithm, this paper proposes a model of fast closed tree paralleled algorithm on the platform of dynamic cloud. Aiming at the random allocation strategy of cloud computing platform Hadoop, the paper puts forward CDA-GA to meet the requirements of the minimized consumption cost. Moreover, on the foundation of CDA-GA, it proposes the dynamic cloud platform model. The parallelization of traditional frequency closed tree mining algorithm and clustering algorithm and is applied in the dynamic cloud platform, this paper designs a closed tree clustering algorithm framework. Experimental results show that the algorithm is feasible and fits into clustering analysis under massive amounts of data.
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Computer Engineering. 2013, 39(9): 84-87. https://doi.org/10.3969/j.issn.1000-3428.2013.09.018Aiming at the problem of the clustering analysis on massive data for traditional clustering algorithm, this paper proposes a K-means clustering ensemble algorithm based on MapReduce. It generates component clustering results with different number of cluster by the K-means algorithm, improves co-association matrix, and gets a final result automatically via the number of times sample pair co-occurred. Experimental results show that this algorithm can effectively improve the quality of clustering, and has good scalability, fits to clustering analysis on massive data.
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Computer Engineering. 2013, 39(9): 88-93,108. https://doi.org/10.3969/j.issn.1000-3428.2013.09.019To meet the demands of heterogeneous scattered computing resources, this paper presents an implementation method of a frame-based virtual computing environment by analyzing the current situations, characteristics and application ranges of several virtual environments, including the overall framework and its service components, as well as the relationship between the various components and communication method realized. It optimizes the service architecture based on hierarchical design method, designs the service module and finally builds a virtual computing platform. Experimental results on seismic data processing shows that the method is feasible and valid, it can integrate heterogeneous scattered computing resources, and fits into different computing organization.
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Computer Engineering. 2013, 39(9): 94-97,113. https://doi.org/10.3969/j.issn.1000-3428.2013.09.020Aiming at the problem of high real-time data demands for ship information systems, this paper applies Data Distribution Service(DDS) for ship information systems, combining with the characteristics of the ship information system, the paper proposes a communication mechanism based on interest filtering. The mechanism can express the interest of subscription more fine-grained to improve communication rate. Simulation experimental results show that the mechanism can meet loose coupling and high real-time demands, and improve the efficiency of communication.
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Computer Engineering. 2013, 39(9): 98-103. https://doi.org/10.3969/j.issn.1000-3428.2013.09.021For improving trust level of internetware and convergence rate of network, this paper introduces the small-world and scale-free network characteristics into the internetware’s trust evaluation and trust components search, and divides internetware into several communities. This paper proposes a new trust evaluation method for the internetware based on complex network and a Trust Internetware Search(TIS) algorithm for trust components based on maximal degree search. Simulation results show that compared with Random Search (RS) and Breadth First Search(BFS) algorithms, TIS algorithm can improve the search efficiency of trust components, reduce network loading, and reduce the length of trust link and trust risk.
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Computer Engineering. 2013, 39(9): 104-108. https://doi.org/10.3969/j.issn.1000-3428.2013.09.022In a multithread parallel program, the master thread is an underlying single point failure under the consumption that the fault-tolerance is handled by the mast thread only. To solve this problem, a Peer-to-Peer(P2P) multithread dynamic fault-tolerance model is designed and implemented. It contains several rounds of fault-tolerance process, fault-tolerance control thread is decided randomly and the fault-tolerance model is generated dynamically in every round. Test work is conducted in the system of EasyPDP, and results shows that this model is able to avoid the single point failure of the master thread, as well as maintain the system speed-up ratio and load balance performance.
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Computer Engineering. 2013, 39(9): 109-113. https://doi.org/10.3969/j.issn.1000-3428.2013.09.023
Traditional Scratch Pad Memory(SPM) management depends on compiler, thus reducing the portability and ability of cross- platform deployment. A SPM management strategy is proposed based on access counting to guide the SPM allocation without compiler support. The approach predicts the application’s core work sets at runtime by counting the memory references. Experimental results show that the new approach reduces the energy 32.5% while keeping program’s stable running compared with Cache systems.
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Computer Engineering. 2013, 39(9): 114-118. https://doi.org/10.3969/j.issn.1000-3428.2013.09.024Application tasks are complex and diverse, which need High Performance Computing(HPC) to solve. To solve the problem that computing efficiency is huge different when they run in different architecture because of different application tasks having different computing features. The Processor-Memory-Communication(PMC) resource requirements of application tasks are perceived to get PMC operator grain, the matched architecture is assigned to the applications. Hypergraph is used to describe the application structure and architecture, and hypergraph isomorphism principle is used to build super-mixed heterogeneous architecture. Experimental results show that reconfigurable architecture which operator grain perception driven has characteristic of high computing efficiency and low energy consumption.
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Computer Engineering. 2013, 39(9): 119-122,127. https://doi.org/10.3969/j.issn.1000-3428.2013.09.025Towards more and more complexity of choosing the expected resource from large-scale resources in the Web environment, an Agent-based pre-selection hierarchical model of Web education resource is presented. The pre-selection hierarchical model is a two-layer filtering model: The filtering algorithm based on semantic similarity is used to match and filter the Web education resources with semantic similarity; The filtering algorithm based on Q learning is used to establish a machine learning model for fine filtration of Web education resources according to users’ feedbacks. Experimental results show that this model can select the resources meeting users’ demands and it has excellent scalability.
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Computer Engineering. 2013, 39(9): 123-127. https://doi.org/10.3969/j.issn.1000-3428.2013.09.026The activities of the programmers for copying, pasting and modifying result in a lot of code clones in the software systems, and increase the cost of software development and maintenance. Aiming at this problem, this paper presents a new clone detection method which uses algorithm based on suffix array to efficiently search repeated token substrings and to detect code clones at last. It develops a clone detection tool SaCD and detects twenty-nine open source software systems of C language. Experimental results show that the SaCD can fastly and efficiently detect Type-1 and Type-2 statement clones in the software. The detection speed of SaCD is twenty times than that of CCFinderx.
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Computer Engineering. 2013, 39(9): 128-133. https://doi.org/10.3969/j.issn.1000-3428.2013.09.027
A new positioning algorithm improved Multi-Dimensional Scaling-MAP(MDS-MAP) is proposed, which attempts to reduce computational complexity of node positioning in data link network. The process of the computation about mode relative coordinates and the aggregation from local network to global network are introduced explicitly, and the optimization strategies are integrated into the algorithm for improving the positioning precision. The analyses to computational complexity and the simulations of the algorithm are presented. Simulation and analysis results show that the algorithm reduces the complexity, and has better positioning performance on precision and scalability. So the algorithm can localize wireless mobile ad hoc network nodes precisely.
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Computer Engineering. 2013, 39(9): 134-136,141. https://doi.org/10.3969/j.issn.1000-3428.2013.09.028For remote monitoring system of single mobile robot, considering the issue of performing task poor accuracy and low complexity, an embedded Web server based on mobile robotic network is designed. A mobile robot network is built by ZigBee technology and an embedded Web server hardware platform based on Cortex-M3 processor. LwIP protocol stack based on μc/OS-Ⅱ operating system in software platform is transplanted. The monitoring system of mobile robot network is completed by application layer program. Experimental result shows that the remote monitoring system of mobile robot network is initially completed.
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Computer Engineering. 2013, 39(9): 137-141. https://doi.org/10.3969/j.issn.1000-3428.2013.09.029An algorithm named Latest Deadline First(LDF) is presented to implement the bandwidth transfer at run time in a real-time system scheduled with the Earliest Deadline First(EDF) algorithm if the remaining bandwidth of the system is not enough for new tasks’ insertion and/or current tasks acceleration. This algorithm starts from the task with the latest instance deadline so that the times of comparison can be as few as possible before the proper task is found to compress, the bandwidth transfer can be done smoothly as quickly as possible. Simulation experimental results show that the maximum time of comparison of the algorithm is 2n, only one or two comparisons are needed in many cases.
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Computer Engineering. 2013, 39(9): 142-145. https://doi.org/10.3969/j.issn.1000-3428.2013.09.030For the poor Bit Error Ratio(BER) performances of Rate Adaptation in Mobile(RAM) environments algorithm in the Rayleigh fading channel, based on RAM, an improved rate adaptive algorithm, named Enhanced RAM(ERAM), is proposed. It adjusts Signal to Noise Ratio(SNR) forecasting mechanism according to the channel change, sets the throughput table initial value according to BER requirements, and uses the ACK frame to carry the next frame transmission rate, so the algorithm reacts to channel variations quickly. Simulation results show that the improved algorithm not only keep better throughput performance, but also can effectively improve the bit error rate performance in the rayleigh flat fading channel model.
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Computer Engineering. 2013, 39(9): 146-149,152. https://doi.org/10.3969/j.issn.1000-3428.2013.09.031The current high availability standard protocol can’t fit the high availability requirement of the gatekeeper which consists of multi-hosts. In order to solve this problem, this paper proposes a high availability protocol model for gatekeeper based on Virtual Router Redundancy Protocol(VRRP). This paper adds a local test module on VRRP, that a test packet is sent to the local on another side while the standard advertisement is sent to the other gap. Text and formally description are presented on function, message format and state transition diagram with finite automata. The model design and flow chart are made to implement the prototype. Experimental results show that when the normal working main machine occurs condition, the standby machine can automatically replace the main machine to work, the main priority with machine failure can take over the work again after returning to normal, and can realise the desired effect.
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Computer Engineering. 2013, 39(9): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2013.09.032In the Three-dimensional Network on Chip(3D NoC) design, the pros of the communication mechanism between the layers will affect the performance of the entire 3D NoC system. In order to solve the above problem, this paper makes some improvements based on the traditional three-dimensional interconnect. For 3D NoC communication problems, this paper proposes a low hardware resource consumption, high performance bus architecture under GEMS simulation platform. It improves routing design, and bus-based 3D NoC router. Experimental results show that the architecture can increase speed-up ratio of common algorithms, and improve overall system performance.
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Computer Engineering. 2013, 39(9): 153-156. https://doi.org/10.3969/j.issn.1000-3428.2013.09.033How to balance the inter communication efficiency and the hardware cost is a key concern for most design of high performance processor. In order to solve this problem, this paper proposes a novel design of arithmetic cluster inter communication structure based on a processor architecture, Multiple Cluster Processor(MCP), on the premise of cluster processing unit of the linear array processor architecture. It mainly includes communication unit structure and the analysis for the communication performance with some typical DSP application. Experimental results show that the design can increase the communication performance about 30% than the other tranditional linear array processor architectures.
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Computer Engineering. 2013, 39(9): 157-161. https://doi.org/10.3969/j.issn.1000-3428.2013.09.034For the problem of Head of Line(HOL) blocking and deaf node in the smart antenna system, a novel packet scheduling algorithm is proposed. Based on the Directional Network Allocation Vector(DNAV), it divides the surrounding space of a tagged node into interference regions and free regions, and transmits packets selected in turn from the data queue if there is an appropriately free region. Simulation results show that the algorithm can eliminate the deaf node problem and resolve the HOL blocking efficiently, which can obtain higher throughput and lower network delay.
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Computer Engineering. 2013, 39(9): 162-166. https://doi.org/10.3969/j.issn.1000-3428.2013.09.035The attack-defense relationship in information security is studied through three game models. The attack and defense equilibrium relationship is discussed with incomplete information dynamic game model, to reach the strategy selection and parameter constraints when the attack and defense relationship getting equilibrium. Taking into account of the long-term and repeatability of the attack and defense relationship, a repeated attack and defense game model under incomplete information is established and long-run equilibrium relationship is reached. Because of the incomplete rationality of decision maker, the limited rationality assumptions is introduced, to verify the validity of the above two models’ conclusion, and getting the effective strategies to solve information security problems with the use of replication dynamic solving evolutionarily stable strategy.
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Computer Engineering. 2013, 39(9): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2013.09.036
Aiming at the problem of key disclose in existed digital signature schemes, a strong forward secure signature scheme, which is based on Guillou-Quisquater signature and Rabin cryptosystem is proposed. In this new scheme, the signer can produce one signature key by the traditional forward technology, and then generate another key with reverse thinking. The use of the two keys makes attackers can not forge the signer’s previous and subsequent periods of valid signatures even if they get the signer’s keys of the current period. Analysis result shows that it is correct and secure, moreover, it has the property of strong forward security. It is also less time-consuming than existing shcemes.
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Computer Engineering. 2013, 39(9): 170-173,177. https://doi.org/10.3969/j.issn.1000-3428.2013.09.037Concerning that the Intuitionistic Fuzzy c-means(IFCM) clustering algorithm has a deficiency of easily falling into a local optimum, an improved IFCM which combines the traditional IFCM with the upgraded Genetic Algorithm(GA) is proposed. The traditional GA is upgraded from two aspects：the fitness standardization and the group diversification. The upgraded GA is more effective in global optimization, which can overcome the IFCM’s shortcoming of local optimum. Then the improved IFCM algorithm is innovatively practised in intrusion detection, and contrastive experiments on data sets KDD CUP99 show that, compared with IFCM algorithm, this algorithm advances the clustering precision effectively and has good reliability and feasibility.
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Computer Engineering. 2013, 39(9): 174-177. https://doi.org/10.3969/j.issn.1000-3428.2013.09.038The traditional quantization algorithms lead high original disagreement rate in the secret key extraction courses, which can reduce the final secret key rate. Aiming at this problem, a pretreatment method based on parity checking is proposed in this paper. The legitimate parities divide the quantization results into groups, and exchange the parity of the groups over a public channel. It removes the groups whose parities are disagreed to reduce the original disagreement rate. Simulation results demonstrate that the new pretreatment method can not only have excellent ability of reducing the original disagreement rate, especially in the case of high original disagreement rate. The remainder ratio of this pretreatment method is improved by nearly nine times when the original disagreement rate is 0.26.
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Computer Engineering. 2013, 39(9): 178-182. https://doi.org/10.3969/j.issn.1000-3428.2013.09.039Aiming at the more and more obvious security problems of embedded systems, this paper puts forward a model for embedded system survivability analysis. Based on the analysis of the research results of survivability at home and abroad in recent years, it proposes a formalized definition of embedded system survivability, establishes three submodels of system threats, system survivability requirements and strategies, and thus forms a set of general process on systematic survivability analysis. Analysis results show that this model can assess quantitively embedded system survivability effectively and analyze major factors influencing system survivability by assessment results.
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Computer Engineering. 2013, 39(9): 183-185,189. https://doi.org/10.3969/j.issn.1000-3428.2013.09.040To improve the accuracy of the hardware trojan detection, a method based on the correlation analysis is presented. After a power modeling of the trojan, the feasibility and defect of the detection method by using the classical correlation coefficient are analyzed, the detection coefficient is optimized according to the characteristics of trojan detection, and the detection method depended on the region overlap ratio is presented. Experimental results show that this method can provide more than two times of robustness when the detection accuracy declined about 6% compared with the classical correlation coefficient.
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Computer Engineering. 2013, 39(9): 186-188,200. https://doi.org/10.3969/j.issn.1000-3428.2013.09.041For Ad Hoc network is vulnerable to the wormhole attack and wormhole attack is dangerous and difficult to defend, this paper proposes a secure routing method based on time and number of hops. By comparing two limits of the time difference and the hop number difference, it effective chooses the safer route and abandons the route which may exist wormhole attack in order to establish the credible data transmission channel. NS2 simulation experimental result shows that this method can significantly improve the wormhole attack detection rate and reduce the packet loss rate in data transmission.
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Computer Engineering. 2013, 39(9): 189-191,205. https://doi.org/10.3969/j.issn.1000-3428.2013.09.042Aiming at key leak issue in proxy blind signature, this paper combines the concept of proxy signature, blind signature and the forward security, proposes a proxy blind multi-signature scheme based on elliptic curve. In this scheme, proxy signer can represent the interests of a number of original signers to generate a valid signature. It uses authorization certificate, the Hash function and elliptic curve cryptography to enhance system security, even proxy signature private key leaks, previously generated proxy blind signature is still valid. Analysis result show that this scheme can effectively resist the original signer’s internal attack, and it has security. Compares with the scheme based on ElGamal signature scheme, it has higher computational efficiency.
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Computer Engineering. 2013, 39(9): 192-195. https://doi.org/10.3969/j.issn.1000-3428.2013.09.043It can provide valuable information of commodities for value-added services such as parity and price querying to automatically extracting content of commodities from these Web pages in e-commerce sites. An effective method of Web content automatic extraction is proposed for these Web pages, including denoising the target page by comparing tag tree with sample page and mining the data-rich region from target page by computing similarity between sub-trees based on tree-matching and extracting the data records from data enrichment region. Experimental result for five e-commerce Web sites shows that the precision rate of this method is higher than Mining Data Records(MDR) method, and the recall rate is high.
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Computer Engineering. 2013, 39(9): 196-200. https://doi.org/10.3969/j.issn.1000-3428.2013.09.044
Bacterial Foraging Optimization(BFO) algorithm is simple, robust and has global search capability. However, the speed of BFO is slow and it often seems to fall into local optimum. To improve the search capabilities of BFO and avoid its premature convergence, a new type of Quantum Bacterial Foraging Optimization(QBFO) algorithm is proposed by integrating binary code quantum evolutionary algorithm into BFO. Quantum triploid chromosome is used to represent bacteria, and Quantum Rotation Gate(QRG) is used to update bacteria’s state. To test the new algorithm’s optimization performance, a research based on benchmark functions is conducted. The results indicate that the new type of QBFO shows better results than BFO and quantum genetic algorithm in convergence rate, stability and looking for the global optimal solutions weather common function or multi-peak function.
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Computer Engineering. 2013, 39(9): 201-205. https://doi.org/10.3969/j.issn.1000-3428.2013.09.045This paper proposes an improving Camshift algorithm based on depth data in order to realize real-time human body objects tracking in depth image. This algorithm computes depth probability distribution function of human body objects, combining the morphological characteristics of people. Different weight factors are given to the different part of human on depth probability distribution function. It finds human body objects in a frame after several times of iterations, uses the modified Camshift algorithm. Kalman filter is also applied in this work to predict the position of people in 3D space. Doing experiments on 1 200 frames of depth image, results present that this algorithm are effective to track moving human body on depth image even though the objects are partly covered or the shapes are regular changed. For the common one or two people situation, the tracking accuracy rate is over 95%, which is better than traditional Camshift algorithm.
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Computer Engineering. 2013, 39(9): 206-209,213. https://doi.org/10.3969/j.issn.1000-3428.2013.09.046The research of Electroencephalogram(EEG) signals is an important means of diagnosis of brain disease. Taking EEG signals of epilepsy for example, for the complexity of the seizures, the evolution process is studied. It uses of the method of the Proper Orthogonal Decomposition(POD) to decompose and compress the EEG signals, chooses multiple variables to reflect electrical pathological characteristic of EEG brain, and uses the improved method of Fisher discrimination to classify the signal, determines the key points of the dynamic evolvement process of EEG signals. Experimental results show that combined with POD decomposition and Fisher discriminant method, it can not only reduce the workload of data analysis, and can effectively distinguish the EEG signal dynamic evolution process.
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Computer Engineering. 2013, 39(9): 210-213. https://doi.org/10.3969/j.issn.1000-3428.2013.09.047Aiming at solving the problem of the uncertainty of the local invariant features number used for image classification, based on a variety of local distribution areas analysis, this paper proposes a completeness expression of local invariant features. Local invariant features are obtained based on the local complete graph generated by adding all the weighted spatial distribution value of Gaussian in the subtraction gray value scale space. Classification experimental results using Bag of Feature(BOF) show that compared with traditional methods, this method improves classification accuracy by 5%~10%.
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Computer Engineering. 2013, 39(9): 214-217. https://doi.org/10.3969/j.issn.1000-3428.2013.09.048In the conditions of complicated backgrounds and different illumination, as face detection based on Adaboost algorithm usually has higher false alarm rate, a new method based on the Adaboost algorithm and the Clifford vector product is proposed in this paper. Most of the non-face region is quickly excluded by the Adaboost classifier. The candidate region is verified basing on the face prior knowledge. If verification failure, according to Clifford vector product properties, searching for the region which has higher similarity with the region that need to be verified again, when their vector product is higher than threshold, this paper can judge that it is a face region. The comparison of this method with Viola-Jones method, experimental result shows that this method can detect face with high detection rate, suppresses the error detection rate, and is highly robust to face detection.
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Computer Engineering. 2013, 39(9): 218-221. https://doi.org/10.3969/j.issn.1000-3428.2013.09.049
The current quantum evolution algorithms based on the Bloch spherical coordinates have slow convergence rate and poor robustness. Aiming at the two shortages, a new self-adaptive Quantum Genetic Algorithm(QGA) which is based on the characteristic of Fibonacci sequence is proposed. In the process of searching the optimal solution, a self-adaptive factor λ is introduced to reflect the relative change rate which is relative to the difference of the best individual’s objective fitness between the parent generation and the child generation. The convergence rate and direction of the algorithm can be improved by adjusting the factor. It is constructed the rule of updating the rotation angle Δφ and Δθ which is based on Fibonacci sequence by studying its properties. Using the new algorithm to deal with the multidimensional complex functions, theoretical analysis of algorithm time complexity and the simulation results show that the new algorithm improves the convergence rate, efficiency and stability robustness.
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Computer Engineering. 2013, 39(9): 222-226. https://doi.org/10.3969/j.issn.1000-3428.2013.09.050A heuristic algorithm for haplotype reconstrucion, named H-MEC, is proposed based on the Minimum Error Correction(MEC) model. H-MEC reconstructs the columns of a pair of haplotypes one by one. It partitions the Single Nucleotide Polymorphisms(SNP) fragments that cover some SNP site into two sets according to the values of the corresponding SNP site, and reconstructs haplotypes by using the fragments of the set which contains more fragments. The experiments are conducted by using the haplotypes on the chromosomes 1 of 60 individuals in the CEPH sample, which are released by the international HapMap project. Experimental results indicate that under various parameter settings, H-MEC can obtain higher reconstruction rate than Fast Hare algorithm and DGS algorithm. Moreover, H-MEC still has high efficiency even for reconstructing long haplotypes.
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Computer Engineering. 2013, 39(9): 227-232,236. https://doi.org/10.3969/j.issn.1000-3428.2013.09.051For the problem of multi-path planning in global path planning for ships, a multi-path planning method based on niche Particle Swarm Optimization(PSO) is proposed. Based on the idea of Genetic Algorithm(GA) to solve multi-modal function, it takes the formation of niche, isolated evolution and crossover operator into the PSO, uses the main particle swarm to decompose the region, and the sub-particle swarm to optimize the local region respectively to accomplish the multi-path planning for ships. Simulation results show that this method can plan multiple optimal and sub-optimal paths correctly and efficiently.
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Computer Engineering. 2013, 39(9): 233-236. https://doi.org/10.3969/j.issn.1000-3428.2013.09.052A nonmonotonic trust region algorithm for solving Semidefinite Programming(SDP) is proposed in this paper. The equivalent smoothing equations of the optimal condition are obtained by exploiting the Fischer-Burmeister function that is extended to the matrix domain, and the center of the path of SDP is rewritten. The algorithm makes full use of first-order gradient information of the current iteration point to solve the trust region subproblem, and a new trust region radius selection mechanism is proposed. Simulation results show that the algorithm runs faster than the classical interior point algorithm for general scale semidefinite programming problems(n, m≤30), for large-scale semidefinite programming problem(n, m＞30) the algorithm is suitable for handling Norm min, Lovasz these two kinds of problems.
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Computer Engineering. 2013, 39(9): 237-239,244. https://doi.org/10.3969/j.issn.1000-3428.2013.09.053An image registration and fusion method based on multi-scale analysis is proposed, which focuses on multi-source video mosaic. In terms of registration, the method compensates for the lack of traditional registration method, which is unstable on scale changes, and makes the corner detection much more stable and accurate. In terms of fusion, in order to overcome the shortcomings of traditional fusion algorithm in frequency domain, multi-resolution image fusion method based on multi-scale analysis is adopted, which not only has localized capacity in both space domain and frequency domain, but also provides more sensitive and strong degree information for human visual. The feasibility of the algorithm is verified by experimental simulation. The result shows the extracted corner is more accurate and fusion effect is more ideal compared with traditional methods.
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Computer Engineering. 2013, 39(9): 240-244. https://doi.org/10.3969/j.issn.1000-3428.2013.09.054Human motion analysis based on traditional dimensional reduction methods often overstresses topology preservation and reconstruction precision which results in incomprehensible low-dimensional subspaces. To solve this problem, this paper proposes a Block Principal Component Analysis(BPCA) based method to analyze motion capture data and further synthesize human motions interactively. By applying BPCA to different body parts, low-dimensional motion parameters which are semantically meaningful can be obtained. Taking jumping motion as the example, experimental results show that by intuitively adjusting these motion parameters, desired new motions can be generated in real-time.
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Computer Engineering. 2013, 39(9): 245-249,253. https://doi.org/10.3969/j.issn.1000-3428.2013.09.055For some cases of new or moving threats and task changing in the practical dynamic circumstance, a new roll Particle Swarm Optimization(PSO) multistep forecasting planning algorithm based on battlefield situation prediction is proposed in this paper. By using the Kalman filtering and probability theory, it completes the situation prediction for threat source, and the probability of the target task. Combined the upgrade PSO arithmetic with the roll optimization, it can adjust the path in real time by multi-step planning and one-step executing. Simulation result indicates that this algorithm plays well in dynamic circumstance especially in aspect of prediction the threat state and responding to the task changing.
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Computer Engineering. 2013, 39(9): 250-253. https://doi.org/10.3969/j.issn.1000-3428.2013.09.056
Aiming at the higher computing complexity based on Genetic Algorithm(GA) signal sparse decomposition algorithm, the electrocardio signal Matching Pursuit(MP) improved algorithm based on GA is proposed. It is combined the characteristics of electrocardio signal, and the window functions are established by electrocardio signal characteristic waveform. The signal is divided into energy concentrated and sparse parts, and is respectively processed using a different algorithm procedure and parameters. Experimental results show that the amount of computation is reduced by 1/3 than the original algorithm, this algorithm improves the computing speed of the electrocardio signal sparse decomposition and compression processing performance.
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Computer Engineering. 2013, 39(9): 254-257,276. https://doi.org/10.3969/j.issn.1000-3428.2013.09.057In order to improve the accuracy of eye detection in driver fatigue detection system, this paper presents an eye detection method based on Cost-sensitive Support Vector Machine(CSVM). The feature vectors of eyes are extracted by Gabor filter after preprocessing, and its dimensionality is reduced by Principal Component Analysis(PCA). The resultant feature vectors are used to train a CSVM to classify the eye and no eye, so as to verify the candidate eye area. Experimental results show that the proposed method can reduce the error rate and improve the reliability of the classifier.
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Computer Engineering. 2013, 39(9): 258-262,280. https://doi.org/10.3969/j.issn.1000-3428.2013.09.058An self-adaption hybrid optimization algorithm with fusion of Ant Colony(AC) algorithm and Differential Evolution(DE) algorithm is proposed to solve the problem of complicated function global optimization. The new algorithm utilizes DE algorithm with the mutation and crossover operation to avoid AC algorithm premature convergence, and utilizes the pheromone positive feedback effect to speed up evolutionary algorithm search, and automatically adjusts searching range. Experimental results show that compared to the AC algorithm and DE algorithm, this new algorithm greatly improves the global optimization search efficiency.
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Computer Engineering. 2013, 39(9): 263-266. https://doi.org/10.3969/j.issn.1000-3428.2013.09.059The objective of this paper is to improve the quality of image interpolation, enrich non-linear image interpolation algorithm. This paper presents a simplified neural network interpolation algorithm, in which the Back Propagation Neural Network(BP-NN) is adopted to construct the best interpolation model. Two sets of experiments determine the best topology of the BP network’s model, the optimal sampling model, the number of sampling points, and describe the time-consuming of each group model quantitatively. Experimental results show that a 512×512 pixel image interpolation using BP-NN can obtain the Peak Signal to Noise Radio(PSNR) 1dB~2 dB higher than Linear Average(LA) method, while the number of pixels in training sets is 50 000 with the topology of 8-16-1. Therefore, the proposed algorithm performs better visual quality.
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Computer Engineering. 2013, 39(9): 267-270. https://doi.org/10.3969/j.issn.1000-3428.2013.09.060
Aiming at the invalid problem to short extent at motion blur in Augmented Reality(AR) by applying Radon transformation method, a method to simulate motion blur of virtual object based on video see-through by combining the Radon transformation and Canny is proposed. It contains obtaining the parameters of Point Spread Function(PSF) according to the proposed method and realizing the real time rendering of motion blur based on GPU. Experimental result proves that the proposed method has a good performance in simulating motion blur for both long and short extent and realizes seamless fusion of virtual world and real world in video see-through AR system.
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Computer Engineering. 2013, 39(9): 271-276. https://doi.org/10.3969/j.issn.1000-3428.2013.09.061In the serial and parallel multi-strategy ontology matching process, there exits the problems of repeated calculation, low matching efficiency and difficulty of polymerizing multiple similarity matrixes. This paper proposes a new multi-strategy ontology matching process based on the combination of ontology feature information. Making use of the element level information such as name, comment, instance to do the initial matching, during this stage part of the entities’ relation can be determined. For the ones that can’t be determined to be matched, their internal and external structure information can be used to calculate the similarity between them. Experimental results show that this method can reduce the matching calculation effectively, and at the same time, the combination of specific information can ensure matching accuracy. It also proves the method has good matching effect and efficiency.
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Computer Engineering. 2013, 39(9): 277-280. https://doi.org/10.3969/j.issn.1000-3428.2013.09.062Fusion Detection Probability(FDP) is an important tactics index for radar net, but it is difficult comprehension and usage to commander. In order to solve this problem, this paper puts forward a visualization method based on contour line filling. Sampling algorithm of arbitrarily battlefield district is presented, calculation model for fusion detection probability of the sampled spatial spot is built, the algorithm of a non-close curve changing to closed curve and the region extraction between two equivalent lines next to each other are designed. In the condition of no jamming and with jamming, it analyzes the FDP’s visualization results of radar net which composes of three radars. It is proved that the results of FDP are very visualization. Commanders can master the radar’s detection probability for arbitrarily position in the radar’s task region, also they can know the change of FDP when the radar net is jammed.
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Computer Engineering. 2013, 39(9): 281-284,288. https://doi.org/10.3969/j.issn.1000-3428.2013.09.063Based on the issues that asymmetric information between customers and service providers, both organized and cultural differences, project risk whose large-scale, long life cycle and large capital, information security and intellectual property, etc., this paper proposes IT outsourcing risk assessment model based on factor analysis and risk matrix. Factor analysis and risk matrix are used. Borda analysis method can make the quantitative evaluation of key factors affect level true. The case analysis shows that the risks of service relationship management and providers’ ability are of the highest level for IT outsourcing projects.
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Computer Engineering. 2013, 39(9): 285-288. https://doi.org/10.3969/j.issn.1000-3428.2013.09.064Considering the problem that the traditional bit-reversal algorithm is only fit for radix-2 Fast Fourier Transform(FFT) data reordering, a novel approach based on mapping recursion is proposed for radix-r FFT data reordering. The mapping recursion process is proved to be convergent, of which the recursion times is lbN, while the parameter N refers to the input number of FFT, thus affording the guideline for the implementation by hardware.
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Computer Engineering. 2013, 39(9): 289-292. https://doi.org/10.3969/j.issn.1000-3428.2013.09.065
To facilitate mail handling of courier company, a low power consumption mail identification system design based on Radio Frequency Identification(RFID) is introduced which is focused on anti-collision algorithm to prevent tag collision. Low power consumption design is also considered from components, power and software. The specific design process of algorithm and results of simulation are given. Experimental results show that the new algorithm is significantly improved in terms of identification efficiency and communication complexity compared with traditional algorithm. This system can realize the fast collection of email messages, real-time and visual message management.
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Computer Engineering. 2013, 39(9): 293-297. https://doi.org/10.3969/j.issn.1000-3428.2013.09.066In order to establish the model of realistic trees, the tree model is divided into static model and dynamic model. The static modeling constructs with expanding two and a half dimensional modeling method and collision principle. The object suffers wind power that the force is calculated by momentum theorem. The value of rupture limit is compared with Young modulus. It is determined object to fracture or sway, and constructs tree dynamic model in the nature. Simulation results show that, using this method can quickly and efficiently build tree model.
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Computer Engineering. 2013, 39(9): 298-302. https://doi.org/10.3969/j.issn.1000-3428.2013.09.067Based on introducing the definition, satisfiability and stable model of constraint logic program, this paper studies the text expansion method of constraint logic program and the text prefix power set expansion method of constraint logic program bound atomic and equivalent properties of logic program before and after expansion. By analysing the definition of well-founded model of normal logic programs, the well-founded semantic model of basic constraint logic program based on minimal fixed point is given, which is based on the minimal fixed of constraint logic program. The model’s rationality is proved. The transformation of constraint logic programming into horn is feasible.
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Computer Engineering. 2013, 39(9): 303-307. https://doi.org/10.3969/j.issn.1000-3428.2013.09.068Traditional ontology research lacks description of dynamic characteristics, has the tennis problem and does not support analysis of relationship between space and time. Due to issues mentioned above as well as increasing demands from practical application, event ontology attracts more and more attention from scholars and becomes research hotspot. This paper provides an overview of existing research on event representation and event ontology model. The main contents are followings: Give definition of event, do comparative analysis in different areas and provide practical notes for event related application. Introduce existing formalized representation models for event ontology and analyze them from perspectives of different application fields. Look forward to future development trends and application prospects of event ontology.
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Computer Engineering. 2013, 39(9): 308-310,316. https://doi.org/10.3969/j.issn.1000-3428.2013.09.069This paper researches the circuit self-repairing on the evolution technology by the use of Virtual Reconfigurable Circuit(VRC) technology in order to further improve the viability of electronic system under a severe environment. It builds a gate circuit model for the digital circuit evolution and designs a binary chromosome encoding according to VRC technology, puts forwards the working process to realize circuit self-repair and discusses ways to diagnose and repair circuit fault. In the simulation that a single particle in the space burns the logic gate in the DC brushless motor control circuit, common SA faults are produced, leading to abnormal operation of the motor. By means of online evolution method, the motor may rotate again by skipping wrong units. Experimental result demonstrates that the evolution method may effectively solve SA faults in a circuit, thus improving the reliability of a circuit.
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Computer Engineering. 2013, 39(9): 311-316. https://doi.org/10.3969/j.issn.1000-3428.2013.09.070Most navigation applications are confined to 2D image-text on smart phones currently. This paper presents an Augmented Reality(AR) navigation browser based on the sensors of Android smart phones in order to provide the visitor more real and excellent experience and direction. This paper proposes a tracking and registration algorithm based on the GPS and attitude angle of smart phones and realizes rendering by composite graphic transformation to make the outdoor scene and digital navigation information merge. The system chooses recording GPS information on the campus instead of picking the data from network map and stabilized the data collected by mean and variance. The browser in this paper presents the guide information more clearly, interacts with the users more conveniently, and makes the visiting experience more realistic. The experiment result on campus shows its practicability and feasibility.
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Computer Engineering. 2013, 39(9): 317-320. https://doi.org/10.3969/j.issn.1000-3428.2013.09.071To solve the problems of limited control range, low management efficiency, low-flexible for urban landscape lighting control system and to realize intelligent remote control, this paper proposes an intelligent control system for Light Emitting Diode(LED) landscape light, which includes an intelligent control terminal based on Pulse Width Modulation(PWM) dimming technology, and a remote communication system integrating RS485 bus, communication converter and Internet network. This paper presents the hardware circuit design and software design process for intelligent control terminal, system communication protocol and remote control methods. Experimental results demonstrate that the control system has features of reliable data transmission, fast response, low cost, and it is easy to realize the distributional long-distance control and management.
Volume 50 No 4
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