20 March 2010, Volume 36 Issue 06
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Computer Engineering. 2010, 36(06): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2010.06.001A rule is defined to describe the logic of text processing, and an engine is designed to execute the rule, with which text processing is simplified from programming to writing rule. A model of the rule is defined based on XML. The rule includes atom-rules, rule-sets, rule-applications and data contexts. The rule can match text with regular expression, and transform the matched results with escape character and script language. An experiment of extracting Web topic text is given to verify the rationality of the rule and the efficiency of the engine.
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Computer Engineering. 2010, 36(06): 5-7. https://doi.org/10.3969/j.issn.1000-3428.2010.06.002A novel Time Difference Of Arrival(TDOA) location method is proposed. Chan algorithm is used in rough location estimation and the result is stored in belief space as experience knowledge. To realize the final location estimation, the Cultural Algorithm(CA) is used to get the optimum coordinates by solving the maximum likelihood function in TDOA. The proposed method can effectively avoid being trapped into local optimum and improve the location precision by history knowledge. Simulation experimental results show the method has the ability of strong stability, high precision and rapid convergence.
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Computer Engineering. 2010, 36(06): 8-11. https://doi.org/10.3969/j.issn.1000-3428.2010.06.003A transaction processing of collaborative service model and analysis based on Stochastic Petri Net(SPN) is put forward. The enterprise collaborative services in a number of the most representative transaction processing is analyzed. The logistics system of E-commerce systems is taken as example, based on SPN modeling, the equivalent simplification and performance evaluation are used. The original model and transaction processing model of system performance and response time is compared.
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Computer Engineering. 2010, 36(06): 12-14. https://doi.org/10.3969/j.issn.1000-3428.2010.06.004Based on the parallel algorithm for restarted Arnoldi method by using data parallel model, a parallel algorithm for refined restarted Arnoldi method is presented. To impair the negative impact on parallel performance due to weak scalability, Tthe parallel algorithm presented implements parallel computing refined vectors by using task graph model and reduces the communication cost. As a result, the algorithm achieves parallel computing efficiently. Numerical experiments on KD-50-I show that the parallel algorithm presented performs good scalability and efficiency.
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Computer Engineering. 2010, 36(06): 15-17. https://doi.org/10.3969/j.issn.1000-3428.2010.06.005The information of operation load and task accomplishment status of distributed system software is important for system improvement and new structure design. This paper presents distributed light load monitor technology for large scale network topology information collection system. Information monitor technology based on Manager/Agent model and multithread probe, and the Agent technology based on Simple Network Management Protocol(SNMP) are used to collect and transfer load information and task accomplishment status information. This method has characteristics of low load, low disturbance to system operation, high timeliness and high expansibility.
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Computer Engineering. 2010, 36(06): 18-20. https://doi.org/10.3969/j.issn.1000-3428.2010.06.006
In order to improve the positioning precision of wireless Ad Hoc network nodes with spot GPS, this paper presents a GPS method for relative positioning of nodes. The nodes in network get their spot positions with GPS modules calculating synchronously and using the same satellites, and then get the relative positions between nodes which can decrease the measurement errors. The algorithm is suitable for positioning of wireless Ad Hoc network for no GPS base-stations needed. The method is implemented in a Zigbee network platform and experimental results indicate that the positioning error is improved to less than 5 m.
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Computer Engineering. 2010, 36(06): 21-23. https://doi.org/10.3969/j.issn.1000-3428.2010.06.007Key technologies of Mobile Remote Control(MRC) are studied based on mobile network. There are obvious differences between mobile and computer devices, such as display capacity, network bandwidth, and Human-Computer Interface(HCI). Methods of hierarchical desktop mapping, adaptive data transmission mechanism and HCI compensation on mobile device are introduced to solve such issues. One prototype is implemented and tested. Results show that MRC is technically feasible.
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Computer Engineering. 2010, 36(06): 24-26. https://doi.org/10.3969/j.issn.1000-3428.2010.06.008The Maximum Entropy(ME) model is used to detect Uyghur sentence boundary. The training procedure does not require hand-crafted rules, part-of-speech tags, or morphological information, but uses readily available features, such as word length and syllable. To determine the best feature set, tests are performed on the different combinations of features. Experimental results show the best feature set is quite robust, and achieves recall of 97.72%.
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Computer Engineering. 2010, 36(06): 27-28. https://doi.org/10.3969/j.issn.1000-3428.2010.06.009Disk file accesses are localized just like RAM access localization in the virtual memory architecture. Most file accesses localize few files. Aiming at this problem, using the Zoned-Disk technology, a dynamic optimizatiom method is proposed. Based on the sampling and statistic results, the frequently accessed files are moved to the zone which is with higher data transfer rate in a Zoned-Disk. Theoretical analysis and practical experimental results show this method improves the I/O performance of the whole system.
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Computer Engineering. 2010, 36(06): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2010.06.010In order to detect Distributed Denial of Service(DDoS) attack accurately and timely, a new detection method based on Principle Component Analysis(PCA) and wavelet analysis is proposed. Software model and algorithm for detection of DDoS attack is presented. In addition, key reasons for the change of the Hurst’s value in the new method are analyzed. Experimental results show the method reduces the dependence for threshold, promotes the detection rate, avoids the situation of fail report and distort. It also improves the detection speed.
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Computer Engineering. 2010, 36(06): 32-34. https://doi.org/10.3969/j.issn.1000-3428.2010.06.011This paper researches the scientific collaboration weighted network based on local world, and how evolving time, cooperators in each paper and weather consider consanguinity on the network affect the structure of evolving network. Results show that the value of Q does not increase with evolving time but exists a best time to make Q max. Community structure becomes more evident with the incensement of Q. A demonstration collaboration network is compared with a simulation one, and the result shows that they have almost the same community structure characteristics.
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Computer Engineering. 2010, 36(06): 35-38. https://doi.org/10.3969/j.issn.1000-3428.2010.06.012The parallelization and optimization of Brute Force(BF) algorithm in Cell BE environment is the basic of migration of this kinds of algorithms to Cell BE environment. According to the architecture of Cell BE computation-acceleration model is used as the programming model, and the mechanism of dual-buffer, Mailbox, DMA-list are evaluated as the data transfer mechanism for performance tuning of BF algorithm. Results show that each transfer mechanism can improve the performance. Different degrees of performance improvement are achieved when two or three mechanisms are used together, and the combination of all three mechanisms gets the highest performance.
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Computer Engineering. 2010, 36(06): 39-41. https://doi.org/10.3969/j.issn.1000-3428.2010.06.013In the Maximum Clique Problem(MCP), setting m as a threshold means that it is easy to compute MCP of a graph whose vertices are not greater than m, and the time complexity is O(d). An exact algorithm to compute MCP in low-degree graphs is presented. The algorithm solves MCP successfully by dividing the vertices of the graph gradually and computing MCP separately. The algorithm is easy to be realized, and the time complexity is O(d•n3). n represents graph vertices, the maximum degree of vertex in graph is lower than m, or the graph can make all the vertex degree lower than m by gradually deleting the vertices which are lower than m.
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Computer Engineering. 2010, 36(06): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2010.06.014Aiming at the problem that the common algorithm often suffers high-complex computation problem, this paper presents an improved association rule algorithm based on vector method, which can map the database into a Boolean matrix by scanning the database only one time. Meanwhile, the frequent itemset can be generated by using simple vector operation. As a result, the number of the frequent items generated by using proposed approach decreases sharply. Experimental results on coronary heart disease data set, including comparisons with the common Apriori approach, illustrate the effectiveness of the proposed algorithm.
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Computer Engineering. 2010, 36(06): 45-48. https://doi.org/10.3969/j.issn.1000-3428.2010.06.015The complicated contents and structures of XML data lead to problems of hard usage and maintenance for data access programs. Aiming at the problem, this paper proposes value objectified model which gets transformation between XML data and Value Object(VO) in object-oriented programming languages. XML data parsing issues are centralized in one module with several algorithms, which sets XML data users free from XML data parsing and strengthens the program maintainability. Engineering application and experimental results demonstrate that this model is efficient.
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Computer Engineering. 2010, 36(06): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2010.06.016Aiming at multi-platform Web development, this paper realizes model management and translation rule management for Model Driven Architecture(MDA) with XML and XSLT separately. It uses template technology to extend the code transformation tache for Platform Independent Model(PIM). Highly effective Web development mode is constructed. Software maintainability, portability and cross-platform characteristic of the software are enhanced. Development of E-learning remote teaching system is realized by using this mode.
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Computer Engineering. 2010, 36(06): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2010.06.017In collaborative filter recommendation systems, the performance of user similarity measuring can be improved by filling the sparse marking matrix. Different filling method has different effect on similarity calculation result. To resolve this problem, this paper makes recommendation by using nearest neighbor algorithm on marking sets constructed by three kinds of filling methods separately, analyzes the measure performance optimized by two methods of traditional similarity measures and the similarity based on cloud model, and selects the most effective similarity measure optimization scheme for each filling method.
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Computer Engineering. 2010, 36(06): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2010.06.018In order to enhance index speed, based on analyzing R-Tree and R*-Tree, this paper proposes a new forced reinsert algorithm. It improves the multi-dimensional index structure to enhance search process. Experimental results show that this algorithm has better performance in index space utility, index dynamic creating and index retrieval compared with traditional algorithms.
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Computer Engineering. 2010, 36(06): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2010.06.019In multi-attribute range query on structured P2P, the number of hops and number of messages required depend on both the number of peers and the size of range to be queried, and vast messages are incurred when attribute value changes. In order to solve these problems, this paper proposes a Peer Dynamic Grouping(PDG) based multi-attribute range query mechanism. Simulation results show that in PDG, the number of hops and number of messages needed are independent of the range size and the peers number. The number of messages needed for attribute update is reduced. The cost of maintaining peer groups is low.
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Computer Engineering. 2010, 36(06): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2010.06.020A text retrieval method is proposed in Gnutella-like networks, which resorts to text clustering to construct a semantic overlay in the unstructured Peer-to-Peer(P2P) network. Each node maintains several long-link neighbors and short-link neighbors to build a small world P2P networks. Neighbors update is processed during the query and response. This makes it rapidly to find out the networks topology. Experimental results show that small world P2P network yields higher recall and takes on the characteristics of small world with greater clustering coefficient and lower average path length.
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Computer Engineering. 2010, 36(06): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2010.06.021Aiming at the problem of the interconnection delay in Very Large Scale Integration(VLSI), this paper proposes a method of minimum- delay Steiner Elmore routing tree, which is based on considering the interconnection delay as the piecewise convex function for searching distances. The method expands the searching space so as to find the best connection point, meanwhile, it sets up an effective searching solution to modify the routing tree repeatedly so as to reduce the total length of the tree. Experimental result shows that the improved routing method can dramatically reduce the searching space, increase the search speed, and it has better performance when the impedance has greater impact in delay.
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Computer Engineering. 2010, 36(06): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2010.06.022In regression test, the internal behavior of programs with different versions are compared by using value spectra. The comparison of programs is converted to the comparison of the state of the functions to estimate where the deviation occurs and to find the function of deviation from the root. It introduces deviation-propagation call tree to record the deviated function, and proposes two kinds of heuristic ways to reduce the deviation from the positioning of the scope of the root to make the location more accurate.
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Computer Engineering. 2010, 36(06): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2010.06.023Soundness, relaxed soundness, or weak soundness are not satisfactory for workflow patterns based on π-calculus. Aiming at the problem, this paper proposes the concept of lazy soundness to analyze workflow. Lazy soundness extends structural soundness by taking the semantics of the process nodes into account. In order to express semantics of the nodes, it considers π-calculus representation of a process graph, which includes formal semantics.
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Computer Engineering. 2010, 36(06): 73-76. https://doi.org/10.3969/j.issn.1000-3428.2010.06.024Based on formalized definition of Signal and Test Definition(STD) standard, static and dynamic model for Automatic Test System(ATS) software platform is built. The relationship among interfaces is demonstrated while drawing the class diagram, the signal state change diagram is improved, the running sequence of the platform is designed. Experimental results show that this platform can realize the function of signal synchronization and trigger through Sync and Gate interface between signal modules.
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Computer Engineering. 2010, 36(06): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2010.06.025In order to make total benefit maximize for cache, based on byte hit ratio, this paper gives streaming media cache replacement algorithm by using 0-1 knapsack to set up a proxy cache model. Experimental result shows that this algorithm can reduce occupied bandwidth, enhance cache read-in efficiency, and it has a higher hit ratio.
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Computer Engineering. 2010, 36(06): 80-83. https://doi.org/10.3969/j.issn.1000-3428.2010.06.026To ensure behavior consistency of components during dynamic evolution and avoid illegal evolution, this paper proposes a component model based on process algebra. It introduces initiate request port and internal connection into the model to formally describe the components and their interaction protocol, gives some theorems and verification algorithm. Example proves that this component model can verify the component interface compatibility, exterior interactive behavioral consistency and run-time behavioral integrity in dynamic evolution.
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Computer Engineering. 2010, 36(06): 84-85. https://doi.org/10.3969/j.issn.1000-3428.2010.06.027This paper proposes a high-performance Hierarchical Complex Event Detection(HCED) method to overcome the drawback of the current Radio Frequency Identification(RFID) complex event detection methods. Based on basic query plan of SASE, it supports hierarchical complex event detection and uses parallel algorithm at different level to improve the performance. Experimental result shows that the method has better performance and flexibility than traditional complex event detection methods.
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Computer Engineering. 2010, 36(06): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2010.06.028The normal vector at each point is estimated by finding a least square fitted plane of that point and its neighbors, and all of the estimated normal vectors are globally adjusted. Gaussian and mean curvatures at each point are estimated by quadric fitting. Eight dimensional feature vectors consisting of coordinates, normal vector, mean curvature and Gaussian curvature are taken as input feature vectors. By applying the fuzzy maximum likelihood estimate clustering method, the segmentation is implemented. Experimental results show the validity of the method.
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Computer Engineering. 2010, 36(06): 89-90. https://doi.org/10.3969/j.issn.1000-3428.2010.06.029Mining all frequent itemsets in dense datasets is very expensive. Aiming at this problem, linked list array, a new data structure, and a fast method of Mining Frequent Itemsets(MFI) based on it are proposed. This method creates linked list array for each item, only needs scan database one time, uses depth-first search strategy to generate all MFI. The algorithm reduces search space by using constraint condition. It demonstrates the algorithm with standard dataset, and the experimental results confirm that the mining algorithm can significantly improve the speed of mining MFI compared with other algorithms.
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Computer Engineering. 2010, 36(06): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2010.06.030According to the characteristics of the data objects on spherical surface and the needs of spatial database query, this paper proposes two methods for handling Nearest Neighbor(NN) query on spherical surface, which are the query method base on the spatial index structure in Euclidean space named SPINS and the method of spherical surface projecting the plane named CTPS. The performances of the two methods are analyzed with dynamic dense dataset and dynamic sparse dataset. The result shows that the two methods can handle NN query of the data objects with the different properties on spherical surface efficiently.
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Computer Engineering. 2010, 36(06): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2010.06.031Aiming at the problem that conventional test automation techniques are not suitable for component, this paper presents a script-based component test automation framework. By combining and improving object-oriented unit test automation framework xUnit and data-driven test framework, it can achieve component test script automated generation, script automated execution, results automated verification and logging. A case indicates that the framework is effective and of relatively high degree of automation.
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Computer Engineering. 2010, 36(06): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2010.06.032Aiming at the local character of migrating workflow exception and architecture of working position, this paper proposes a working position exception processing model based on ECA rule and Case-Based Reasoning(CBR). This model detects the exceptions through the proactive detection and passive detection, handles the exceptions using the ECA rule and the CBR method, realizes working position exception handling by using local exception rule bank. Application results show that this model enhances the ability to handle predictable and unpredictable exception.
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Computer Engineering. 2010, 36(06): 100-101. https://doi.org/10.3969/j.issn.1000-3428.2010.06.033InsPecT can identify protein post-translational modifications by blind search, but needs a lot of calculation time and with high complexity. Aiming at the problem, this paper uses P2P mode and master-slave mode to realize two parallel optimization schemes. Comparison results show that with adopting dynamic data distribution and timely response between master processor and slave processor, parallel InsPecT with master-slave mode receives a better load balance and higher speedup effect.
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Computer Engineering. 2010, 36(06): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2010.06.034This paper proposes a method of simplifying complex Web page script and mapping it into tree structure easy to operate. It does not depend on DOM tree, and does not need utilize htmlparser bag to parse. By calculating text similarity, it calculates the similarity between the content of tree node and headings of different levels to determine the usefulness of the text information, cleans the Web page and extracts the content information. Experimental results show that the method has better universal property and accuracy rate in main text extraction.
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Computer Engineering. 2010, 36(06): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2010.06.035This paper studies the state of bandwidth allocation for Ad Hoc network, analyzes the definition and restraint in bandwidth allocation according to characteristics of Ad Hoc network. Three models concerning the relationship of fairness and efficiency on bandwidth allocation for Ad Hoc network are studied and compared. According to the careful analysis and comparison of the existing bandwidth allocation algorithms, it proposes resolution for primary problems at present.
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Computer Engineering. 2010, 36(06): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2010.06.036In order to improve the performance of 802.11 DCF in noisy channel, by improving the probability of q of the network size, this paper proposes a novel channel access control mechanism for IEEE802.11 WLAN named SDCFf(network Scale-based DCF in fading channel), and constructs its Markov chain model. The performance of SDCFf is evaluated with the successful transmission probability and the saturation throughput. According to the network size and channel conditions, the probability of the parameter p is adjusted via either doubling or resetting the contention windows dynamically to optimize the performance of WLAN. Experimental result shows that, when the network size changes, SDCFf performs much better than DCFf does.
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Computer Engineering. 2010, 36(06): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2010.06.037According to the QoS multicast routing problem, which is to find the least cost multicast routing tree that satisfies bandwidth, delay and other constraints, this paper proposes a distributed ant colony optimization algorithm. In this algorithm, a multicast tree’s forest is formed during the ant movement progress. The objective of ant movement is to connect all the trees in the forest to form a single tree. The most important advantage of the algorithm is distributed implementation. Simulation experiments show that this algorithm performs well both in results and convergence speed.
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Computer Engineering. 2010, 36(06): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2010.06.038P2P stream media takes plenty of bandwidth resources. This paper presents a strategy for data schedule from the perspective of detecting the unnecessary data downloads promptly. It can help node avoid unnecessary data downloads and reduce download cost of the system. A data download mathematical model is introduced, which converts the problem of improving the playing continuity of stream media to the problem of finding the optimal solution for job schedule with deadline. Experimental results show that the strategy can reduce download cost effectively and obtain perfect playing continuity.
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Computer Engineering. 2010, 36(06): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2010.06.039Based on the mechanism for power saving of type III in IEEE 802.16e, this paper takes into account the memoryless nature of user initiated packet arrival, to build a Geom/G/1 queue with multiple vacation. By using an embedded Markov chain method, some queue system measurements are derived. Correspondingly, the formula of system measures in terms of the average packet response time and energy saving ratio are presented. Considering both the energy saving and the system response time, it develops a cost function. Numerical results are given to demonstrate the dependency relationships between the system measures and sleep length, and the optimum lengthes of sleep mode for different offered loads are given.
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Computer Engineering. 2010, 36(06): 120-122. https://doi.org/10.3969/j.issn.1000-3428.2010.06.040Client/Server(C/S) pattern is a service-oriented pattern, but transport of network data is address-oriented transport, and they are not consistent. In order to resolve their inconsistency, this paper proposes a concept of Network Service Identifier(NSI), and designs an algorithm of Service-Oriented Networks Transmission(SONT) based on NSI, which uses unicast IP address to implement multicast, supports defense against DDoS attacks on the Internet, and implements transport of service-oriented network data. Theoretical analysis and simulation results show the satisfactory results.
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Computer Engineering. 2010, 36(06): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2010.06.041In opportunistic routing, the calculation of distribution matrix is too large, especially as the network size increases, the performance of opportunistic routing is seriously affected. This paper proposes an opportunistic routing algorithm based on the dynamic address for the problem, which makes the calculation of distribution matrix from the entire network down to one-hop neighbor nodes. Experimental results show that according to the dynamic address reflecting the relative physical location of network nodes, the calculation of distribution matrix can be greatly simplified. In the large-scale network, average-hops are decreased by 5%~10% and throughput is increased by 7%~26% by the routing algorithm.
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Computer Engineering. 2010, 36(06): 126-127. https://doi.org/10.3969/j.issn.1000-3428.2010.06.042Aiming at high control overhead and long packet delay of the traditional Ad Hoc On Demand Distance Vector(AODV) routing repair algorithm, and improved algorithm is proposed. By delivering 2hop_RREQ and NOTICE packets during route repair phase, the repair near the broken links of the improved algorithm is limited at the range of 2 hops. Compared with the traditional algorithm, the results obtained by NS2 show that the routing cost is decreased by 50% and the packet delivery ratio is increased by 5%.
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Computer Engineering. 2010, 36(06): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2010.06.043This paper studies the methods of algebraic attack on PRESENT with the help of MiniSAT 2.0. It also analyzes the S-box of PRESENT and finds fourteen equivalent implicit functions of the S-box, which includes no redundancy functions and the number of normal expressions of each function is no more than six. Using different number of plaintexts, it does algebraic attack on low-round PRESENT, and the result is the best one at present. Result shows that if knowing plaintexts, it can recover the keys of five-round PRESENT using 80 bit keys in less than 121 h and if knowing the selective plaintexts, it also recovers the keys of six-round PRESENT in less than 203 h.
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Computer Engineering. 2010, 36(06): 131-132. https://doi.org/10.3969/j.issn.1000-3428.2010.06.044According to different needs to security hash algorithms under different circumstances, this paper adopts the thought and method of the reconfigurable architecture, and designs a reconfigurable hash cryptographic chip. Experimental results based on FPGA of the family of Stratix II of Altera Corporation show that the proposed system reaches throughput values equal to 727.853 Mb/s for SHA-1, 909.816 Mb/s for SHA-224/256, and 1.456 Gb/s for SHA-384/512 respectively.
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Computer Engineering. 2010, 36(06): 133-136. https://doi.org/10.3969/j.issn.1000-3428.2010.06.045Aiming at the weakness of manual analysis, this paper proposes a hybrid analysis method against protocol. An automatic analysis tool is applied based on the manual analysis in order to reach completeness. Some vulnerability is found when applying the hybrid method to check mobile IPv6 protocol. Simulational experiment results show that the hybrid method can analyze non-security protocols and find the subtle vulnerability, and it is a systematic method with completeness guarantee.
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Computer Engineering. 2010, 36(06): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2010.06.046Considering previous schemes need trusted third party, this paper proposes a multi-message signature scheme. The scheme is based on bilinear pairing and utilizing t key-evolving independence. Especially, when one client needs the signatures from the directed signature centre, the signature center can sign for many messages, and the signatures can be batch (publicly) verified. And its security is proved.
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Computer Engineering. 2010, 36(06): 140-141. https://doi.org/10.3969/j.issn.1000-3428.2010.06.047Aiming at the problem of the module reduction operation, this paper proposes a fast algorithm based on Fixed Trinomial Or Pentanomial(FTOP) algorithm over GF(2m). By dynamically counting the index and offset of grouping words, the proposed algorithm overcomes the disadvantage of FTOP that of only available for fixed reduction polynomial, the proposed algorithm is faster than the one-time-one-bit algorithm when reduction polynomial has less terms of 123(m<719), maximum 89%, average about 30%, and with arbitrary trinomial or petanomial, it has the same speed as the FTOP’s.
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Computer Engineering. 2010, 36(06): 142-145. https://doi.org/10.3969/j.issn.1000-3428.2010.06.048This paper proposes a blind watermark method embedded in MPEG-2 video bitstream. The watermark is embedded in motion vectors of all B frames which are grouped, every group embeds one bit watermark. By adopting an adaptive strategy and modifying the parity of the value of motion vector, the modification of the number and the value of motion vector are reduced, it improves the imperceptive effect in the compressed video. Experimental result shows that the algorithm is fairly resistant to multi-time coding and bitrate changed attack, at the same time, the proposed algorithm can satisfy real-time embedded and extracting watermark.
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Computer Engineering. 2010, 36(06): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2010.06.049The possibility of DoS and DDoS attacks is pointed out on streaming media service by analyzing the procedure of RTSP and it is verified by simulating attack scenarios. A defense scheme on streaming media service’s DoS and DDoS attack problem is proposed. This scheme is based on location hiding and balance distribution techniques and can be a good reference for many streaming media applications like VOD, IPTV, etc.
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Computer Engineering. 2010, 36(06): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2010.06.050Using data mining technology to detect malicious code, this paper proposes a feature selection method based on weighted information gain. This method can select effective features more correctly by combining the advantage of information gain with classwise frequency. A malicious code detection system is implemented which adopts binary N-gram and variable-length N-gram as the feature extraction method, weighted information gain as the feature selection method. Several classifiers are used to detect malicious code in the system. Experimental results prove that this method can effectively improve the detection and accuracy rate.
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Computer Engineering. 2010, 36(06): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2010.06.051This paper analyzes Cross-Site Scripting(XSS) vulnerability, proposes an XSS vulnerability classification method, optimizes the XSS detecting model, and accomplishes a dynamic auto-detecting tool. It remedies the shortage of the original tool, and carries out a better result. Experiments show its feasibility and advantages compared with similar products.
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Computer Engineering. 2010, 36(06): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2010.06.052Aiming at the problems of great computation of pairings in Public key Encryption with Keyword Search(PEKS) schemes are still time consuming and inefficient, and the proposed PEKS schemes can not resist to relay attacks, on the base of researching the PEKS, this paper proposes a more efficient PEKS scheme. Comparing with the previously mentioned PEKS schemes, the new PEKS scheme retains the advantages of the previously one and it is more simple, efficient and resistible.
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Computer Engineering. 2010, 36(06): 158-159. https://doi.org/10.3969/j.issn.1000-3428.2010.06.053This paper analyses the safety of stream cipher algorithm of CSC-(n,N) family. It proves that the first word of the key stream produced by CSC-(n,N) is 0 with a probability 2-n~2-2n approximately which is verified by trials. A distinguishing attack on CSC-(n,N) is presented. In the attack, the key stream of CSC-(n,N) can be distinguished with a random stream with the correct probability 0.84 by its first word produced by 23n+2 keys of CSC-(n,N).
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Computer Engineering. 2010, 36(06): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2010.06.054Jphide is a steganography method based on control-mode table. It is more complex than other methods. Besides, there is no good method to attack it. This paper analyzes the structure of embedding message, selection process and embedding mode. It finds two statistical characteristics. It gives a detecting method, which can estimate the length of secret message as rate is 10%~50%.
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Computer Engineering. 2010, 36(06): 163-165. https://doi.org/10.3969/j.issn.1000-3428.2010.06.055This paper proposes a distributed intrusion detection method based on immune evolution computing in grid computing environments. Immune evolution computing and method of generating detector and gene base are used to improve initiative and self-adaptive of distributed intrusion detection system. Grid security environment is used to realize load balancing and improve parallel processing ability. The effectiveness is proved by experiments. Comparing with intrusion detection method based on artificial immune, false detection rate is reduced by 0.37%, parallel processing ability is improved and processing delay is reduced while assuring detection rate.
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Computer Engineering. 2010, 36(06): 166-168. https://doi.org/10.3969/j.issn.1000-3428.2010.06.056This paper proposes a novel group key update scheme based on the analysis of the existing group key schemes. It uses the one-way function, XOR operation and the pseudo-random function to reduce the storage complexity and computation, and uses the group key which is based on time series to increase security, introduces two variables which divide the key update process into two parts, the necessary update and the auxiliary update, it significantly reduces the number of logic update. Analysis shows that the robustness and scalability of the program is good and it has a widely scope of application.
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Computer Engineering. 2010, 36(06): 169-172. https://doi.org/10.3969/j.issn.1000-3428.2010.06.057In order to make the cryptosystem over curves safe and efficient, this paper introduces Eisenstein ring and introduces the conic curve over the residue class ring , where is the product of two different impartibility numbers, which satisfies over . Conic analog of blind signature based on over conic curve is presented and E-cash in the E-payment system is taken as an example to discuss the application of digital signature over . The security is based on the difficulty in factorizing large integer and computing discrete logarithm on Abel group . The digital signature based on the conic curve shows the merits on conic curve that it is easy to embed plaintext, and its computing speed is rapid and is easy to implement.
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Computer Engineering. 2010, 36(06): 173-174. https://doi.org/10.3969/j.issn.1000-3428.2010.06.058Aiming at the problems of low authentication efficiency and its complex process, a double-way authentication scheme of ELGamal digital signature is proposed. The Key Distribution Center(KDC) is introduced as the third aspect, which distributes the public keys and communicates with both sides. Analysis results show this scheme improves the complexity than discrete logarithm and the computing efficiency is better than others. The scheme may have some comprehensive application in identification and digital signature.
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Computer Engineering. 2010, 36(06): 175-177. https://doi.org/10.3969/j.issn.1000-3428.2010.06.059This paper proposes a digital image encryption algorihm which is based on the chaotic map network. A pseudorandom sequence is generated from a chaotic map network, which consists of four 1-D piecewise-linear maps. The pseudorandom sequence and the standard magic square are used for image encryption. The algorithm security is carried out with theory analysis and digital simulation. Experimental results show that the proposed encryption scheme has high security.
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Computer Engineering. 2010, 36(06): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2010.06.060In view of the problem that the existed artificial neural network will destroy the obtained knowledge when it studies new knowledge, according to expansion idea of the biological intelligence, a learning method of Fuzzy Incremental Neural Field Based-on Granular Computing(FINFGC) is proposed. This method organically combines the character of the quotient space with the theory of neural field and introduces in the autonomous neural network, makes use of the partitioning method and the inserting mechanism, divides the big task into the small task so as to realize the knowledge accumulation, inheritance and perfection unceasingly. Experimental results show this method is rational and feasible.
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Computer Engineering. 2010, 36(06): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2010.06.061Aiming at the shortcomings of slow convergence and easy to fall into local minimum when using Quantum Genetic Algorithm(QGA) to optimize complex continuous functions, this paper proposes a Novel Improved Quantum Genetic Algorithm(NIQGA). It adopts the dynamic adjustment strategy to adjust the quantum rotation corner to speed up convergence rate, and uses the cross strategy of excellent individuals to get crossover operation to enhance local search ability. Test results based on typical complex continuous functions show that NIQGA is feasible and effective.
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Computer Engineering. 2010, 36(06): 184-185. https://doi.org/10.3969/j.issn.1000-3428.2010.06.062This paper introduces the common methods for solving the collision problem of general fuzzy matching in fuzzy reasoning mechanism, including the Haming distance method and the exponent method. It presents the exponent-like method and the absolute value difference and product method based on the exponent method. The two methods are improved to be correct according to the definition of similarity. Numerical example comparison results show that the absolute value difference and product method has higher performance than the three other methods.
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Computer Engineering. 2010, 36(06): 186-188. https://doi.org/10.3969/j.issn.1000-3428.2010.06.063Particle filter approximates to the posterior probability density function with a set of weighted random sample points and realizes accurate estimation of arbitrary state model. It combines Rao-Blackwellized Particle Filter(RBPF) with Multiple Hypothesis Tracking(MHT) and separates multiple target track problem into two parts: estimation of the posterior probability distribution of data association and estimation of the single target track based on the data association. The former can be solved by Sequential Importance Resampling(SIR), and the latter can be solved by minimum mean square error estimation with Kalman filter. Experimental results show that the calculation particle count and the calculation amount can be reduced by using optimal importance distribution.
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Computer Engineering. 2010, 36(06): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2010.06.064Regarding the inadequacy in recall rate and match speed in content-based image search, an effective method based on vocabulary tree is presented, using fuzzy quantification. The SIFT(Scale Invariant Feature Transform) descriptors are extracted from the query image, which fuzzily quantifies these features to words using vocabulary tree. In this way, the query image can be represented as a weight vector. The query vector is compared with database vectors to measure the image similarity. Experimental results show this method can greatly shorten the response time, and improve the recall rate significantly.
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Computer Engineering. 2010, 36(06): 192-195. https://doi.org/10.3969/j.issn.1000-3428.2010.06.065The union of fuzzy logic and the neural network forms the fuzzy neural network, it simultaneously has the advantages of expressing the human knowledge, storing and learning distribution information storage. This paper proposes a Dynamic Fuzzy-Neural Network(D-FNN) algorithm based on parameter adjusting. It uses Extended Kalman Filter(EKF) method to divide the overall algorithm into the linearity and the misalignment part. The linear parameter is decided by Least Squares(LS) method and the filter method, the misalignment parameter is directly decided by the training sample and heuristic method, the linearity and the misalignment parameter can carry on the real-time renewal. Simulation results indicate that this algorithm can guarantee more succinct structure and shorter learning time.
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Computer Engineering. 2010, 36(06): 196-197. https://doi.org/10.3969/j.issn.1000-3428.2010.06.066A vehicle tracking method based on corner feature and Mean-shift is presented for efficient tracking object that continuously changes in size. The same in size’s kernel windows of model object are built based on corner features. The Mean-shift algorithm is carried out one by one. According to the tracking result, the object’s final position is estimated. Experimental results show this method is simple, reliable, and can track the vehicle stably.
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Computer Engineering. 2010, 36(06): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2010.06.067A novel method for automatic image annotation is presented. The new model is based on a probabilistic formulation which poses annotation as a multi-class classification problem. It tries to estimate the correlation between visual features and semantic labels by using the groups of images that share the same associated labels through kernel density estimation. In addition, CPAM-based visual features are introduced to improve the efficiency of kernel density estimation without requiring prior image semantic segmentation. Experiments on the benchmark data set show this model achieves higher accuracy than the previously published results.
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Computer Engineering. 2010, 36(06): 201-203. https://doi.org/10.3969/j.issn.1000-3428.2010.06.068The on-line performance and off-line performance are provided to evaluate the performances of Election-Survey Algorithm(ESA) used in functions optimization. The relativity between the selected parameters of ESA and the algorithm performance is analyzed by researching the numerical optimal problem of standard test functions. It is expected to observe the changes of the responses by the changing the parameters of ESA so as to obtain some reference basis of parameters selection. Numerical optimal experimental results of standard test functions show that on-line performance and off-line performance are improved by variation of parameters.
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Computer Engineering. 2010, 36(06): 204-205. https://doi.org/10.3969/j.issn.1000-3428.2010.06.069This paper extracts the upper triangular half of the covariance matrix of knowing direction signals to construct the direction estimation model. Aiming at the problem that the best parameter of Least Squares-Support Vector Machine(LS-SVM) is hard to select, it uses real-coded heuristic genetic algorithm. Aiming at the approximate performance estimation of model incoming wave direction, it optimizes the parameters of LS-SVM with Gauss kernel function. The estimation precision is improved. Experimental results show that this method has high precision, high real-time performance and a broad application future in wireless direction finding field.
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Computer Engineering. 2010, 36(06): 206-209. https://doi.org/10.3969/j.issn.1000-3428.2010.06.070On the basis of the idea of unifying Active Appearance Model(AAM) and Active Shape Model(ASM), this paper mines the relation of peg points fully and proposes a method to construct local vein model. It modifies the matching algorithm to improve location precision and matching speed of feature point. Facial expression feature obtained by this algorithm is input to the nearest neighbor classifier. Classification results indicate the high recognition rate of the algorithm.
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Computer Engineering. 2010, 36(06): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2010.06.071This paper presents a binary shuffled frog leaping algorithm and an assignment method for cognitive radio spectrum based on it. Simulations are conducted to compare this method and color sensitive graph coloring algorithm. Results show that under the maxmization rule of whole network efficiency and fairness efficiency, the assignment method for cognitive radio based on binary shuffled frog leaping algorithm has higher performance. The binary shuffled frog leaping algorithm can find the ideal optimal solutions while the solution obtained by color sensitive graph coloring algorithm has a large deviation with the optimal solutions.
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Computer Engineering. 2010, 36(06): 213-214. https://doi.org/10.3969/j.issn.1000-3428.2010.06.072This paper puts forward a method combining with integral projection and Snake model to identify human eye tiredness. It uses Snake mode to detect the eyes, computes the contour of a face to locate eye position, then rotates the eye image to a suitable position. Vertical gradation integral projection is measured to calculate the region around eye, and becomes a waveform picture of vertical gradation integral projection. It calculates the value of the waveform’s three characteristics and uses it to recognize if the eye is in an open or closed state. Experimental results show that this method is simple, effective and fast, and it can also be applied in the inclination of the human eye.
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Computer Engineering. 2010, 36(06): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2010.06.073Aiming at hierarchical B prediction structure utilized in Scalable Video Coding(SVC) standard, this paper proposes a picture-level Content-Adaptive Quantization Parameter Cascading(CAC) algorithm. The Quantization Parameter(QP) value for each picture is decided based on the hierarchical prediction structure and prediction modes of the macroblocks in the picture. Experimental result demonstrates that compared with the technique used in SVC standard, the algorithm increases rate distortion performance by 0.363 dB.
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Computer Engineering. 2010, 36(06): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2010.06.074By analyzing the characteristics of Internet Protocol Television(IPTV) service and the influence of fast forward/backward on the server, a packaging and indexing format of streaming media file optimized for fast forward/backward is proposed. Based on block-level media storage technology, it designs frame type storage strategy. Performance evaluation experiments demonstrate that IPTV server can work more efficiently with the format under fast forward/backward.
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Computer Engineering. 2010, 36(06): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2010.06.075This paper proposes a design scheme of mobile video surveillance system based on WiMAX. It gives the hardware design of front end, chips and the wireless network interfaces. Double buffer and intelligent code rate control policies are used to assure the quality of video when network bandwidth changes or sector switchs in WiMAX. Experimental results and application effect of the system show the validity of the design scheme.
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Computer Engineering. 2010, 36(06): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2010.06.076Aiming at the problem of Multiple Control Unit(MCU) load balance in video conference system, this paper proposes a MCU load balance method based on Agent and a group priority algorithm with lower workload. MCU Load Gathering Agent(LGA) and Load Balancing Agent (LBA) are proposed to gather MCU workload and execute load balance, therefore workload is balanced. Compared with First Request First Allocation(FRFA) algorithm, the method can reduce video transmission delay by 8%.
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Computer Engineering. 2010, 36(06): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2010.06.077Sampling and real-time recording rate of the present signal acquisition system are merely tens of megabytes per second, so that the system can not meet the demands of continuous and real-time signal sampling with high speed and high resolution. To address the problem, this paper designs and implements a signal acquisition card based on Time-Interleaved Analog-to-Digital Converter(TIADC). It can sample analog inputs at 200 MS/s, and achieve 14 bit resolution. Its effective Spurious-Free Dynamic Range(SFDR) is over 80 dBc, and it can reach continuous real-time data recording rate of 400 MB/s.
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Computer Engineering. 2010, 36(06): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2010.06.078An embedded Micro-Controller Unit(MCU) system for mixed-signal processor is introduced in this paper. According to the request of systems reconfiguration, all the instructions stored in the EEPROM off-chip are transferred into the SRAM on-chip and executed. The MCU system is fabricated in SMIC 0.18 µm mixed-signal CMOS process with an area of 1.06 mm2. It operates from 1.8 V power supply. Measurement results show that all of the instructions are executed correctly and it can be used to configure the function of the mixed-signal processor in a way compatible with SPI protocol.
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Computer Engineering. 2010, 36(06): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2010.06.079Aiming at the problems in the earthquake precursory industry that it is heterogeneous to access devices, data processing method is single, and it is difficult to manage all the devices, this paper brings up a mediation-based middleware for heterogeneous instruments, which can shield the physical connection heterogeneity and instrument protocol heterogeneity, and it can convert heterogeneous device to virtual device with unified properties, command set and data result set. A typical scene is presented to validate the method is feasible.
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Computer Engineering. 2010, 36(06): 236-238. https://doi.org/10.3969/j.issn.1000-3428.2010.06.080In allusion to the disadvantage of processing Fill-in Signal Unit(FISU) using CPU, on the basis of analyzing the process of initial aligning and FISU processing in No.7 signaling system, a new design scheme adopting Field-Programmable Gate Array(FPGA) to achieve FISU filter is put forward. The principle figures, communication mechanism between FPGA and CPU, and signal processing flow charts are carried out. ISE and ModelSim software are used to achieve simulation. Simulation result proves that the scheme is correct, feasible and effective.
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Computer Engineering. 2010, 36(06): 239-240. https://doi.org/10.3969/j.issn.1000-3428.2010.06.081Aiming at the request of stability of data storage about NAND Flash, this paper analyzes the disadvantages of traditional handle scheme and proposes a handle scheme to deal with bad block based on Field-Programmable Gate Array(FPGA). It constructs bad block shield function in FPGA to shield the bad block. This method thoroughly eliminates the influence on other operation caused by bad block. By using this method, data can be successfully stored in flash and it ensures the correctness of data. This method is carried out in a project with high stability.
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Computer Engineering. 2010, 36(06): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2010.06.082To increase the efficiency of verification in design of Application Specific Instruction Set Processor(ASIP), a software-hardware co-verification method which combines the verification of ASIP Register Transport Level(RTL) description with the test of ASIP software development tools(assembler, software simulator) is proposed. Test assemble instructions and data are generated according to the test requirement, and the binary codes are produced by the assembler subsequently. The binary codes are input to the hardware simulator and instruction set simulator at same time, and the results of software and hardware simulation are compared automatically. This method can discover errors in ASIP RTL description, the assembler and the instruction set simulator efficiently, increase the coverage of verification, and shorten the verification cycle of ASIP.
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Computer Engineering. 2010, 36(06): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2010.06.083In the traditional systems of safety control, precision of trajectory parameter is not high and this often results in fake alarms which is due to the systemic error in measurement and trajectory track. Aiming at these problems, based on analyzing the characteristics, the method adopts the intelligent decision way and contains the technology of dealing with safety knowledge, a realization method of making some knowledge-based intelligent decision for the safety control is proposed. Simulational experiment results show that the method is more accurate and extensible, and improves the certainty and authenticity of the safety decision.
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Computer Engineering. 2010, 36(06): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2010.06.084In supply chain collaborative planning, the decisions which are made to achieve the optimal objective of the whole supply chain may trigger conflict between individual rationality and collective rationality. Aiming at this problem, this paper introduces conflict detection method into the supply chain collaborative planning study, establishes a supply chain collaborative planning conflict detection model, and uses negotiation based on Agent to dispel the detected conflict. This model is simulated via an application example, and the results show that introducing conflict detection method into the supply chain collaborative planning can detect conflicts that exist in the supply chain in time, and it is helpful to improve efficiency and scientificity of supply chain collaborative planning.
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Computer Engineering. 2010, 36(06): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2010.06.085Attribute data uncertainty can directly affect the quality of Geographic Information System(GIS)-based decision-making. The lifecycle of GIS attribute data is divided into a lot of stages, such as data collection and preparation, digital information extraction, information integration and the expression of attribute data. This paper explores the propagation of the attribute uncertainty at all stages and constructs propagation model of attribute uncertainty. It concludes synthesis and propagation algorithm of attribute uncertainty and tests the availability and effectiveness of the model.
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Computer Engineering. 2010, 36(06): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2010.06.086According to the characteristics of collaboration network, local-world and the effect of act degree, this paper proposes a novel Local-World evolving model for Collaboration network(CoLW). The model constructs a local-world hierarchical based on complete graphs, and takes the act in collaboration network as a unit to increase a node. The model can unify the generic properties of real-life collaboration networks, scale-free degree distribution, small average shortest path length and high clustering that is independent of network scale. Experimental results show that the CoLW model can depict the topological structure and statistical characteristics of real-life collaboration networks very well.
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Computer Engineering. 2010, 36(06): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2010.06.087Based on the analysis of the structure and the key technologies of smart card Mini_COS on 3G network, a cover model of smart card Bind_Max_COS is proposed, the structure and the construction process of this model are studies. A smart card Bind_Mini_COS which suits for the customs taste is made. And a feasibility analysis and evaluation for this model are described.
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Computer Engineering. 2010, 36(06): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2010.06.088This paper analyzes the algorithm based on the grid points and points out the basis of the algorithm, i.e. the solving of the matrix which indicates the mapping from the target surface to the image surface has the correspondence problem of the calibration points. Through introducing the fiducial marker system, which includes defining the selection criteria of fiducial markers and analyzing their recognition rate from the environment and the wrong recognition rate from each other, an improved progress from extracting the calibration points to calculating their image coordinates and the formulas relative are given. Experimental result proves the algorithm is efficient and liable, and has a practical value for the small FOV in which indoor environments can be controlled.
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Computer Engineering. 2010, 36(06): 262-264. https://doi.org/10.3969/j.issn.1000-3428.2010.06.089It is necessary to analyze feature of input data before intrusion detection. This paper uses Particle Swarm Optimization(PSO) algorithm to select feature, eliminate the redundancy property, reduce the problem size, improve the quality of data classification and speed up the process. The position of the particle is expressed in a binary string. The update strategies of the position, velocity and the selection of fitness function are illustrated. The experiments with KDD CUP1999 and comparative results with Genetic Algorithm(GA) are described. It shows that the method is more efficient for feature selection and classification quality improvement.
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Computer Engineering. 2010, 36(06): 265-266. https://doi.org/10.3969/j.issn.1000-3428.2010.06.090Based on the research on the distributed data collection system Platform Enterprise Reporting Framework(PERF) of Platform Company, some important weakness are found in the traditional process of distributed data collection, which is used to leading to information loss, bandwidth waste and great difficulty in system maintenance. A series of methods including reducing intermediate link are proposed to improve the process of distributed data collection, so that the risk in data loss can be brought down greatly. Analysis in the statistic information about improved system from customer confirms the validity of the method.
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Computer Engineering. 2010, 36(06): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2010.06.091Due to the specialty and diversity of the embedded systems, much tedious transplant work must be done when embedded Linux is deployed on the target embedded system. In order to overcome the blindness of transplant work and speed up the entry markets time of the embedded products, a brief introduction to the embedded system Bootloader(U-Boot as an example) is given, with emphasis on its basic structure and mechanism. Based on the implementation of transplanting U-Boot to HHPPC852T target, a typical method for transplanting Bootloader to a new target is presented, which is simple and practicable.
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Computer Engineering. 2010, 36(06): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2010.06.092According to the economic characteristics of the fishery resources, the fishery resources and decision-making information by graphics is realized. This paper explains ontology replaces knowledge base to build the Spatial Decision Support System(SDSS) which can optimize the mode of knowledge organization and advance the query efficiency. Database, model base, and ontology are comined with GIS, and reliable information events of resources are supplied for the decision-makers. The warning model is integrated with gray forecast model and BP neural network. It analyses the real database from the resources of East Sea in China. Experimental results indicate that this warning model has high precision, and achieves good results.
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Computer Engineering. 2010, 36(06): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2010.06.093This paper proposes a quick and feasible collision detection algorithm for mobile devices which has the drawbacks of low performance and small screen size. The algorithm makes use of the multi-level collision detection and dynamic multi-resolution grid subdivision to reduce the computing time for collision detection, which improves the algorithm performance. In the collision response phase, this paper adopts the time step binary search algorithm to ensure both the computing precision and system efficiency. The mobile billiards game designed for the Company indicates that this algorithm has good performance and real-time interaction.
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Computer Engineering. 2010, 36(06): 276-277. https://doi.org/10.3969/j.issn.1000-3428.2010.06.094To the point of the trajectories of moving objects are inherently uncertain and query accuracy associated with the uncertainty is low, an uncertain trajectories model is extended to the trajectories representation of the moving objects in a constrained network. Based on this model, a probabilistic approach is proposed when the uncertain spatio-temporal point query and range query are implemented and the experiment shows that the probabilistic method can be carried out with better performance.
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Computer Engineering. 2010, 36(06): 278-280. https://doi.org/10.3969/j.issn.1000-3428.2010.06.095Aiming at the problems of current simulation tools are not able to provide schedulability analysis, graphical show of schedule result and ability of dynamic substitution of algorithm simultaneously, this paper puts forward a real-time schedule simulation framework called RTSIM by using python’s matplotlib, dynamical loading technique. Simulating the process of real-time schedule and testing schedulability is a complicated issue. Experimental result shows that RTSIM can test and simulate real-time schedule algorithm well.
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Computer Engineering. 2010, 36(06): 281-283. https://doi.org/10.3969/j.issn.1000-3428.2010.06.096For the conflict between the data-intensive applications and the distributed data storage in the distributed interaction simulation systems, a solution providing general data service within the framework of HLA is put forward, which integrates the data model into the simulation model seamlessly by extending the HLA object model, and the data operating interfaces can be accorded with the federate interface specification due to the extension. Additional optimizing options are provided according to the characteristics of the data service module in the distributed simulation systems, and the common develop flow according to the FEDEP model is discussed.
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Computer Engineering. 2010, 36(06): 284-286. https://doi.org/10.3969/j.issn.1000-3428.2010.06.097In network simulation, network protocol simulation modeling needs huge work and long development cycle. Aiming at this shortage, this paper proposes self-defined multi-terminal business modeling method to simulate modeling of application layer protocol and Diffie-Hellman key exchange protocol. Simulation result show that this method is simple, high-efficiency and high reusable, it also has a higher application value, compared with process model modeling method.
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Computer Engineering. 2010, 36(06): 287-289. https://doi.org/10.3969/j.issn.1000-3428.2010.06.098This paper studies and constructs the model and architecture of Next Generation Business Operation Support System(NGBOSS) towards high-speed and broadband services. The core technology of content billing system based on the strategy is studied and a configurable billing system is implemented. The multimedia services gateway is used to make the new digital interactive media services be automatically accepted, generated and deployed, and end to end services can be implemented automatically. Experimental result shows that the system meets the requirement.
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Computer Engineering. 2010, 36(06): 290-293. https://doi.org/10.3969/j.issn.1000-3428.2010.06.099For enterprise business system integration requirements of flexible, a logical integration of information organizational unit, channel service and an integrated framework model of integration service components are proposed. Using message bus transmission technology and plug-in component technology, through the configuration of different channel services, message service dynamic registration and service provider of the message on the message bus are achieved. Channel service functions can be expansioned through the deployment of integration services components. In the application of the process of traffic information integration, it proves that the model is easy to extend and has good flexibility.
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