20 October 2010, Volume 36 Issue 20
-
Select all|
-
Computer Engineering. 2010, 36(20): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2010.20.001In order to design flexible and efficient security and encryption processing device, this paper proposes a multi-objective joint custom instruction design method. By discovering common frequent computation patterns hidden in encryption algorithms, the flexibility of custom instructions is raised. Custom instructions aiming at five encryption algorithms including DES, AES, Blowfish, RC4 and MD5 are generated by adopting the proposed method. Experimental result shows that the method can fulfill custom instruction design effectively. After instruction set extension, the performance of the five algorithms is improved by 41.9%~63.6% respectively.
-
Computer Engineering. 2010, 36(20): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2010.20.002In order to provide Top-k services with QoS guarantee and effectively reduce the load of the host server and the network involved, this paper proposes a Web service selection method named RTKS-QoS. By quantizing QoS attributes and calculating the value range of the utility function, it efficiently filters the Top-k services to meet the requirements. Experimental result shows that in the premise of ensuring precision, when k does not larger than the number of 12% of the candidate set of services, network load and response time of RTKS-QoS at least increase by 38% and 37%.
-
Computer Engineering. 2010, 36(20): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2010.20.003A heart sound localization method is proposed for heart sounds recorded from subjects in normal noise environment. Heart sounds are recorded from three separate locations on the human chest simultaneously using three sensors. The time delay differences between each two sensors are estimated by correlation calculation. They are used to calculate the coordinates of the source projection points on connections between each two sensors with respect to the coordinates of sensors. The source of the heart sound is located according to the relation of the source and its projection point. Experimental results show that the method is useful to locate the source of the first heart sound recorded from healthy subjects.
-
Computer Engineering. 2010, 36(20): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2010.20.004Taking notice that condition attribute whose value equals with “*” does not participate in the determination of similarity relation in the incomplete decision table based on similarity relation, this paper defines relative important degree and important degree of attributes. According to the important degree of attributes, the heuristic method of searching for assignment consistent sets and assignment reduction in incomplete decision table are presented respectively. Experimental results show that the method can find the assignment consistent sets and assignment reduction of an incomplete decision table, and reduce the search space of reduction.
-
Computer Engineering. 2010, 36(20): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2010.20.005Surface fundamental form describes the local differential features of mesh surface. This paper presents a mesh smoothing and feature enhancement method aiming to deal with these features. This method smoothes and enhances mesh features by modifying the discrete forms of mesh surface. The new mesh is reconstructed in the least square sense with proper constraints added. With the help of fast linear system solver for sparse matrix, the method can achieve real-time processing effect. Experimental results demonstrate that this method is simple and effective. Meanwhile, it has good denoising effect, and can prevent volume contraction and shape distortion to some extent.
-
Computer Engineering. 2010, 36(20): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2010.20.006Aiming at the slow convergence problem of Internet inter-domain routing, this paper proposes a Border Gateway Protocol(BGP) routing convergence algorithm based on Simple Path Vector Protocol(SPVP). It detects the root-cause node in inter-domain link failure to improve the convergence speed of inter-domain routing and reduce the overhead of routing update message with the analysis of four different Tdown convergence boundary value in full mesh network topologies. SSFNet simulation results show that convergence upper limit of this algorithm is O(d).
-
Computer Engineering. 2010, 36(20): 19-21. https://doi.org/10.3969/j.issn.1000-3428.2010.20.007
In order to improve processor core simulation modeling efficiency, a virtual processor modeling method based on SimpleScalar architecture is proposed, and the model aiming at Godson-1 processor reaches 1 000 000 per second with average IPC error of 2.3%. A controllable random event Bus Function Model(BFM) is presented, providing active stimuli generation and on-chip bus verification function for SoC design. Experimental result proves that the solution has broad applicability in processor core modeling and can be seamlessly integrated into mainstream SoC flow.
-
Computer Engineering. 2010, 36(20): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2010.20.008In order to realize carrier acquisition and tracking of high dynamic link better, Doppler frequency shift between high dynamic aircraft and near space receive plat is described and simulated in terms of the motion models of high dynamic aircrafts in near space, and based on the result, the influence on carrier synchronization caused by Doppler frequency shift is discussed. Analysis and simulation results show that Doppler frequency shift achieved in terms of high dynamic motion models can accurately describe Doppler shift trends under high dynamic movement.
-
Computer Engineering. 2010, 36(20): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2010.20.009When original attribute reduction algorithm calculates tolerance relation, there is much repeatedly calculating consumption. And this leads to O(|C|3|U|2) time complexity. Aiming at this problem, based on incomplete decision table, this paper presents a high efficient tolerance matrix computational algorithm whose time complexity is O(|U|2). On that basis, it designs an improved attribute reduction algorithm based on tolerance matrix. Test proves that the time complexity of improved algorithm is reduced from O(|C|3|U|2) to O(|C|2|U|2) with the same space complexity.
-
Computer Engineering. 2010, 36(20): 28-31. https://doi.org/10.3969/j.issn.1000-3428.2010.20.010This paper presents an improved fast Global Motion Estimation(GME) algorithm by combining with two-step method and traditional Gradient Descent(GD) algorithm. Sparsely sampling MSEA(Multilevel Successive Elimination Algorithm) fast Block Matching Algorithm(BMA) is used to get local motion vectors. Iterative Least Square(ILS) method is used to get rough estimation of the global motion parameters and excludes outliers(foreground macro-blocks). The rough global motion parameters is used as initial value and LM(Levengberg-Marquardt) GD optimization method is used on the feature pixels which are selected from the residual sampled blocks that have been excluded outliers with ILS. Experimental results validate that the estimation speed of improved algorithm reaches 11.42 ms/f, it is 1.3 times faster than FFRGMET algorithm, and it gets higher GME precision.
-
Computer Engineering. 2010, 36(20): 32-33. https://doi.org/10.3969/j.issn.1000-3428.2010.20.011
This paper obtains an exponential stability criterion of Networked Control System(NCS) by constructing a delayed difference inequality. On the basis of this new established criterion, it designs a feedback controller in the form of Linear Matrix Inequality(LMI). It does not contain any free-weighting matrices, and can be solved by LMI toolbox in Matlab software. Numerical value simulation result shows that this design has less computational complexity and conservatism, and it is convenient to implement.
-
Computer Engineering. 2010, 36(20): 34-36. https://doi.org/10.3969/j.issn.1000-3428.2010.20.012Global Positioning System(GPS) stoppage and other problems can disable navigation systems. In order to deal with these problems and to obtain GPS fault-tolerance, a novel distributed navigation algorithm is proposed with GPS vestiges. Its intelligent computing models, data structures and working flows are described as following. Monte Carlo method is utilized to evaluate the passable roads. The algorithm performance is analyzed. Simulation results show that it has better GPS fault-tolerance and faster response delays than the traditional method does.
-
Computer Engineering. 2010, 36(20): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2010.20.013
According to the properties of Artifact, semi-structured data is used to represent it. Taking advantage of Predict/Transition Petri-Net(Pr/T-Net), a new method is proposed to formalize the business process model, in which the static predict is the set of Document Type Definition(DTD) which gives Artifact structure and the transition is a kind of first-order logic language which operates the XML. The arrival, persistence and uniqueness of the Artifact are analyzed.
-
Computer Engineering. 2010, 36(20): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2010.20.014According to the conflict classification, it can optimize the computation of the non-deletion rules. It avoids calculating the overlap of the two non-deleting rules. This paper discusses to the Graph Transformation System(GTS) with NAC, may calculate critical pairs, it provides a construction for critical pairs with NAC. It exits an essential critical pairs for every conflict reason, which can use the available smallest context expresses the conflict. Since the essential critical pairs are a subset of the critical pairs, the essential critical pairs can simplify the static conflict detection method.
-
Computer Engineering. 2010, 36(20): 43-45. https://doi.org/10.3969/j.issn.1000-3428.2010.20.015This paper multi-analyses the difference between text chance discovery and text mining from the system definition, application environment and goal etc.. It analyses the background and status, introduces the chance definition, text chance discovery key algorithm and Scenario map analysis etc. main research fields. It indicates the study orientation in the future based on the summarize of current research’s limitation.
-
Computer Engineering. 2010, 36(20): 46-48. https://doi.org/10.3969/j.issn.1000-3428.2010.20.016In order to efficiently reduce attributes of tables with incremental attributes, an incremental attributes reduction is proposed. It figures out the incremental attributes reduction with greedy algorithms, which increasingly constructs approximate reduction and then kickes out unnecessary attributes. The algorithm is valid according to complex analysis and data tests.
-
Computer Engineering. 2010, 36(20): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2010.20.017Single Web service can not meet the demand for practical applications. In order to combine existing services into a new service, this paper proposes a reverse service composition derivation algorithm based on parameter correlation matrix. Web service ontology using predicate is defined, and the process of service composition with predicate calculus is proved. Theory research results get the conclusion that the method is effective and viable.
-
Computer Engineering. 2010, 36(20): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2010.20.018This paper proposes a multi-relational model which is applied to the multi-class imbalanced data. In the preprocessing stage, each class is assigned an Error Correcting Output Coding(ECOC). After setting up the virtual joins between the target and background relations, appropriate aggregation functions are used for different features. On this condition, the data can be divided into training set and validation set. Sub-classifiers are built on the training set in combination with One-vs-All classification method and CrossMine algorithm, and all the sub-classifiers are validated by their AUC values. The ECOC of the target class is compared with the Hamming distance of the linked word produced by the sub-classifiers on the validation set, and the class is chosen which has the shortest Hamming distance for the final result. The validity and effectiveness of the classifier by experiments are shown on both synthetic and real datasets.
-
Computer Engineering. 2010, 36(20): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2010.20.019To address the problem of completeness verification on multi-dimensional data in the applications of edge computing, this paper proposes a Neighborhood-Based Completeness Verification(NBCV) method. The solution creates the neighborhood of a data item by finding the nearest neighbor of the data item in each quadrant. The encrypted data items and their neighborhoods guarantee the completeness of the query results. Experimental shows that the proposed solution can be effectively applied in completeness verification of multi-dimensional data.
-
Computer Engineering. 2010, 36(20): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2010.20.020In the current research area on Web services discovery, solutions with Top-K query and taking the quality of services into account meanwhile are not common. In the view of the situation, this paper presents a solution for Top-K Web services, focusing on the quality of services. The quality data of services are normalized, the quality evaluation function is given, and the dominance relationship between services is defined. Especially, the typical threshold algorithm is improved to propose StopLine algorithm to get Top-K Web services, which converges faster. The algorithm is proved to be more efficient in the experiment.
-
Computer Engineering. 2010, 36(20): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2010.20.021For the conflicting problem between memory assumption and access speed caused by existing caching methods of report, a caching method is provided for structured data. The main characteristic of such method is caching the report data which has the structure of row and column to file as data blocks. The data to be cached as file is partitioned into indexing area and data area, then written to the file via a data blocking algorithm. Using such approach, the need data can be retrieved from the located block by index, and the data rapidly. Thereby, an optimized result can be obtained to the memory assumption and access speed problem.
-
Computer Engineering. 2010, 36(20): 64-65. https://doi.org/10.3969/j.issn.1000-3428.2010.20.022A recursive formula of enumeration number of leftist heap with n different nodes is put forward using the combination method based on the definition, facts and theorems of leftist heap. An algorithm on this formula is also given in this paper and is verified by a program. The work of this paper can provide some reference for n binary tree enumeration that is not a complete tree as well as can provide a foundation for leftist heap’s enumeration generating, random generating and average complexity analysis.
-
Computer Engineering. 2010, 36(20): 66-67. https://doi.org/10.3969/j.issn.1000-3428.2010.20.023
This paper presents a Reverse Nearest Neighbor Queries(RNNQ) algorithm based on Auto-Selection Grid Index(ASGI). ASGI divides the space into an equal size network, and each cell stores moving objects as a bucket. RNNQ algorithm uses the strategy of the bucket’s object number and the grid geometry characteristic to reduce the access node the RNNQ must visit. ASGI will repeat the previous action to decrease the cost again if objects around the query point are too many. Experimental results show that RNNQ algorithm based on ASGI has good query performance and outperforms RNNQ algorithm based on TPR tree.
-
Computer Engineering. 2010, 36(20): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2010.20.024For the semantics between the concepts, this paper presents a fuzzy information retrieval model of multiple related ontologies whose relationships are expressed as fuzzy relations. The process and retrieval mechanism of ontology information retrieval model are illustrated, the effect and influence of applying different types ontology are discussed, and the system following the evaluation method of TREC is estimated. Experimental results prove that the proposed model presents better overall performance and is an natural way to improve retrieval results of users needed.
-
Computer Engineering. 2010, 36(20): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2010.20.025The query function for a centralized system is usually hard to design and costs a large number of server resources. A solution based on distributed data source is discussed to solve these problems, which uses an inverse data access method to improve querying efficiency and reduce programming complexity. It also contains an inheritable module-assembling query scenario to simplify the process of development and deployment, in order to meet the complexity of business requirement.
-
Computer Engineering. 2010, 36(20): 74-77. https://doi.org/10.3969/j.issn.1000-3428.2010.20.026This paper presents a kernel-level solution for the freezing and unfreezing of process on Windows platform. Based on Windows Research Kernel(WRK), it describes a whole skeleton of process freezing, which saves full image of process and support to self-unfreezing. For the process with multi-file handles, by reserving the file handles in process object of kernel ahead, the unfreezing process restores these file handles and corresponding data. Two typical experiments show the way is correct.
-
Computer Engineering. 2010, 36(20): 78-79. https://doi.org/10.3969/j.issn.1000-3428.2010.20.027Workflow engine is the kernel of workflow management system. According to Workflow Management Coalition(WfMC) workflow reference model, analysed the main function of workflow engine, designed various functional modules, realized the basic function and feature with XML Process Definition Language(XPDL) and Java technology. The workflow engine does not rely on Web environment, can be used in Web information systems and desktop application areas. It can be easily embedded into applications for the process to realize the workflow system management function.
-
Computer Engineering. 2010, 36(20): 80-82. https://doi.org/10.3969/j.issn.1000-3428.2010.20.028To mitigate the duplicate codes and improve the adaptability of data maintenance program in database applications, a data maintenance framework based on metadata is proposed. The metadata model can describe the relationship of tables and the inheritance of the tables in object-oriented paradigm. Implementation of the framework including data manipulation SQL statement retrieval, data maintenance user interface generation and adaptability to the table structure alternation is discussed. Practical applications validate the feasibility of the framework.
-
Computer Engineering. 2010, 36(20): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2010.20.029
Aiming at the problem of the inaccurate information in the monitoring based on the current middleware load balancing mechanism, and of the large size of the particle, this paper designs a more precise, more fine-grained load balancing system and its associated load balancing mechanism with the combination of fuzzy logic technology. Record list of load information records load state information, and load transfer list records relationship between service nodes and service requesters. Experimental result shows that the load balancing mechanism can effectively target node overload to better achieve load balancing system services of the cluster.
-
Computer Engineering. 2010, 36(20): 86-87. https://doi.org/10.3969/j.issn.1000-3428.2010.20.030
Aiming at the problem of constraint on network protocols or incurring embedding error in the existing methods, a scalable proximity search method based on cover tree CPS is raised. It is comprised of two parts: cover tree constructing protocol and maintaining protocol, and k nearest neighbors searching algorithm. Attending nodes compute the layers of themselves, so as to construct a layered tree. The neighbor maintaining protocol is responsible for maintaining the structure of cover tree, ensuring the adaptability in the network environment. k nearest neighbors searching algorithm constructs candidate nodes for every level by pruning the cover tree in order to improve the searching efficiency. Simulation results indicate that the accuracy of CPS is better than Tiers.
-
Computer Engineering. 2010, 36(20): 88-89. https://doi.org/10.3969/j.issn.1000-3428.2010.20.031
In the process of integrating “3S”, the choice of a favorable data structure is the key point. This paper analyzes the advantages and disadvantages of both vector and raster data structures, and builds an optimal data structure based on the secondary dividing strategy, which merges the advantage of simultaneity vector and raster and can fulfill the requirement of vector data accuracy. It gives a logical representation of this data structure, and rasterizes the space data simultaneity. Based on that, it discusses the strategy of the collection and overlay analysis of space data based on this data structure.
-
Computer Engineering. 2010, 36(20): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2010.20.032
Greedy linear shift balancing algorithm is presented for ring or linear array to reduce balancing time and the amount of the transferred load. The algorithm can be used for balancing any system in which internetwork contains at least one Hamilton path. It need not a large amount of load transferred among nodes or a large amount of the consumed time. In addition, two-stage greedy linear shift balancing algorithm is presented to improve the greedy linear shift balancing algorithm for mesh etc. Experimental results show that the two-stage linear shift balancing algorithm can reduce execution time when the balancing condition is weaken.
-
Computer Engineering. 2010, 36(20): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2010.20.033In mobile Ad Hoc networks, node movement often makes the topology change frequently. In case not considering stability, link break will be unavoidable on the route and therefore route reconstructing is continuing. In order to improve the stability of routing, this paper prompts a new route protocol called PPC-MAODV. The protocol takes the path stability element and link minimum stability entropy into account of construction. Simulations show that the PPC-MAODV protocol can reduce the end-to-end delay and packets discarded.
-
Computer Engineering. 2010, 36(20): 96-98. https://doi.org/10.3969/j.issn.1000-3428.2010.20.034To solve the problem of negative impact on the performance of Active Queue Management(AQM) in large delay network, an AQM algorithm is proposed based on rate and queue length in large delay network. This algorithm consideres the effect of queue length and packet arriving rate together to indicate congestion degree. An input rate control is used to speed up the responsive time in fuzzy Smith control method. Simulation result shows that the algorithm has a fast response and short convergence time in large delay network and dynamic network environment. It also can control the size of the queue in the buffer to an expected length and achieves high utilization.
-
Computer Engineering. 2010, 36(20): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2010.20.035Scheduling establishment time of distributed scheduling in IEEE 802.16 mesh net has larger effect on delay-sensitive business. Aiming at this problem, this paper let a node requests/grants bandwidth from/to its neighbors in a round-robin fashion based on distribution of tokens, and predicts the number of bytes between two consecutive control messages to establish three-way handshake of distributed coordinated scheduling mode, which guarantees a fair bandwidth allocation among the traffic flows and decreases the time of packets buffered in the queue because of three-way handshake. Simulation results using NS2 show the efficiency of the algorithm.
-
Computer Engineering. 2010, 36(20): 102-105. https://doi.org/10.3969/j.issn.1000-3428.2010.20.036This paper presents a KV Routing Algorithm for High-Performance MapReduce(HPMR) system. HPMR system is an implementation of the MapReduce(MR) model, which accommodates the MR model to the requirements of high-performance computing. The KV routing algorithm is used to create KV routing table by which all the send or receive actions on data are done. The performance of the KV routing table generated by KV routing algorithm directly determines the time cost of the communication phase of HPMR system. Experimental results show that KV routing table created by the KV routing algorithm can improve the communication performance of HPMR system.
-
Computer Engineering. 2010, 36(20): 106-109. https://doi.org/10.3969/j.issn.1000-3428.2010.20.037
This paper proposes a novel Fair Aggregator based on Flows Isolation(FAFI) that combines both Earliest Deadline First(EDF) scheduling and Worst-Case Fair Weighted Fair Queuing(WF2Q). By assembling individual flows in EDF and forwarding aggregated traffic in WF2Q, FAFI overcomes disadvantage in flow aggregating that the end-to-end delay of an individual flow is related to the burstiness of other flows sharing its aggregated traffic. An end-to-end delay bound is derived in the network equipped with proposed aggregator. A performance comparison is done with previous works on the aspects of end-to-end delay bound, network utilization, and scalability.
-
Computer Engineering. 2010, 36(20): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2010.20.038The TCP source congestion control disciplines are introduced to the router congestion control problem, and an Active Queue Management(AQM) algorithm called Expecting Rate Fuzzy Update(ERFU) is proposed. It considers both the afferent flow rate and the inside load, and directly updates the dropping (or marking) probability of each afferent packet based on the TCP source congestion control disciplines to adjust the queue length quickly converging to designated aim. It needs low requirement and performs superiorly and proves to have better performance than ERED.
-
Computer Engineering. 2010, 36(20): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2010.20.039This paper defines three basic conception including sensorial coverage, communication coverage and connectivity coverage, and gives their physical models and mathematical models. It proposes the regular hexagonal node coverage model applying to 2-D region. It is proved that the model can get coverage to repeat the least without loopholes in 2-D region. The least neighbor nodes to ensure connectivity coverage and communication coverage are 6 for 2-D regional coverage based on the regular hexagonal node coverage model, when launching radius of the node is greater than or equal to times of sensorial radius. Node’s sensorial coverage rate is 82.7%. Study result shows that the regular hexagonal node coverage model is more suitable to the 2-D region.
-
Computer Engineering. 2010, 36(20): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2010.20.040Aiming at the problem of repeat coverage and algorithm taking too much time, this paper proposes a coverage optimization strategy of Virtual Material Force-directed Particle Swarm Optimization(VMFPSO) in Wireless Sensor Networks(WSNs). The strategy undergoing optimization performance test is analyzed through the simulation experiment. Coverage rate increases by 9.5 percent, 1.7 percent, 6.03 percent and 3.71 percent and convergence rate increases 23.2 percent, 1.8 percent, 24.5 percent and 24.5 percent compared with elementary PSO, the evolution of Multi-particle Particle Swarm Optimization(MPSO), the traditional genetic algorithms(CGA) and quantum of the New Genetic Algorithm(NQGA) about the optimization effectiveness. Results show that the VMFPSO strategy has better coverage optimization effectiveness than PSO, MPSO, CGA, NQGA.
-
Computer Engineering. 2010, 36(20): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2010.20.041This paper presents a new ring topology Network-on-Chip(NoC) architecture. By improving the input port virtual channel, the architecture completely prevents Head of Line blocking(HoL) and deadlock with one pipeline stage in a like Virtual output Queue(VoQ) way, without consuming too much resource. This paper evaluates the performance of this architecture under some different parameters. Compared with CELL EIB ring implementations, its packet minimum latency is only 11 cycles, while the maximum throughput is 25.6 Gb/s.
-
Computer Engineering. 2010, 36(20): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2010.20.042The merits and shortcomings of existing layered multicast congestion control mechanisms are analyzed respectively. A Fuzzy Logic-based layered Multicast Congestion Control(FLMCC) mechanism is proposed. In FLMCC, each receiver obtains different throughput by subscribing to different numbers of layers according to their expected rates, which is predicted by exponential smoothing prediction model. The sender adjusts sending rate timely to reduce the jitter of sending rate based on the feedback information from receivers by a fuzzy controller. Simulations indicate that FLMCC has fine fairness as well as smoothness, so it adapts the heterogeneous network well.
-
Computer Engineering. 2010, 36(20): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2010.20.043To reflect network attack-defense confrontation situation and solve the problem of strategy dependence, an incomplete information dynamic attack-defense game model is proposed. It constructs network attack-defense confrontation model, and based on the definition of attack and defense actions’ sequence, the method of conversion from attack-defense confrontation model into extensive form game model is presented, then equilibrium strategy solution can be acquired.
-
Computer Engineering. 2010, 36(20): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2010.20.044Presently, many of discriminating methods are coarse-grained. In order to advance the efficiency, this paper introduces a method to indentify the specific files by fine-grained. It builds the samples according to character of the aim-files, picks up the character of BitTorrent(BT) downloading, and compares them. Experiment shows this method can indentify the specific files, and at the same time, enhance the accuracy of the identification.
-
Computer Engineering. 2010, 36(20): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2010.20.045This paper advances a method to ensure aeronautical information safely based on OpenSSL according to ATM network architecture of CAAC and the process of aeronautical information transmission. It researches the key technology about protecting aeronautical information, implements the encryption and digital signature technology, protects the aeronautical information confidentiality, integrity, availability and real-time.
-
Computer Engineering. 2010, 36(20): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2010.20.046To meet the high security needs of WSN, this paper proposes WSN dynamic key management scheme based on tree structure. MAC mechanism and unique ID method are combined. Logic tree key pool is used. Dynamic key update is realized by balance binary tree. Experimental results show that compared with existing schemes, this scheme needs littler energy consumption for computation and communication.
-
Computer Engineering. 2010, 36(20): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2010.20.047Aiming at the shortages of Douglas-Peucker compression algorithm for vector map, this paper proposes an anti-compression watermark algorithm by improving Dougleas-Peucker algorithm. The improved algorithm is adopted to compress vertex data which is important characteristic of vector map. The compressed vertex data are used as host data to embed watermark. Experimental results indicate that a desired progress is achieved by applying proposed algorithm in aspect of anti-compression.
-
Computer Engineering. 2010, 36(20): 140-141. https://doi.org/10.3969/j.issn.1000-3428.2010.20.048Most electronic auction schemes need assistance of a third-party arbitration organization. If the third-party conspires with seller or buyer, buyer’s bid price and seller’s trade secret would be disclosed. Combining with the technology of Bit commitment and blind signature, this paper proposes an electronic auction scheme based on trustless third-party. It meets the demand of a secure electronic auction scheme, and it can withstand the above conspiracy attack.
-
Computer Engineering. 2010, 36(20): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2010.20.049A credible recommendation node set-based reputation model is proposed in this paper which solves the problem in the existent models that the miscarriage of justice for the honest recommenders when peers change their behavior. It divides the recommenders into two sets: the credible recommender set and the set to be taken a further look. The recommendations from the former set constitute the computation of peers’ reputation value. The behavior of the latter set is observed to correct the honest recommender that has been done wrong. Peers transform dynamically between these two sets according to their recommendation performance. Experimental results show the model’s validity.
-
Computer Engineering. 2010, 36(20): 145-146. https://doi.org/10.3969/j.issn.1000-3428.2010.20.050Format-compliant video encryption algorithms have their own merits and defects on safety, operability and decoding time-consuming. Aiming at the situation, this paper proposes a novel format-compliant video encryption algorithm which is convenient, secure, fast and has no effect on the compression ratio. Videos are encrypted by permutation through changing the value of the vertical position for macro-blocks. Simulation results on two standard video sequences show that compared with the original one, the new algorithm is more effective.
-
Computer Engineering. 2010, 36(20): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2010.20.051To solve the problem of all the certificateless signcryption schemes in the literature are built from bilinear mappings on elliptic curves which need costly operations, this paper presents the first concrete pairing-free certificateless signcryption. This scheme is provably secure in the random oracle model, relative to the hardness of the discrete logarithm problem and computational Diffie-Hellman problem. As there is no pairing operation in the new scheme, this scheme is more computationally efficient than others built from bilinear mappings.
-
Computer Engineering. 2010, 36(20): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2010.20.052In order to solve the problems of enormous keys in Kerberos inter-realm authentication, an authenticated certificateless key agreement protocol is proposed. It can overcome the limitations of original Kerberos authentication. It builds a security inter-realm session key only with one round message exchange, and it provides perfect forward secrecy. Security analysis result shows that the improved protocol can solve key management problem and the interception which can not be proved, and it makes the system more secure.
-
Computer Engineering. 2010, 36(20): 153-154. https://doi.org/10.3969/j.issn.1000-3428.2010.20.053
This paper proposes a threshold multi-secret sharing scheme based on key agreement to assure that secret data can not restored by attackers have diddled subsecrets from all the participants. The cheating of dealer and the cheating of participants can be detected. The subsecrets are chosen by the participants themselves and can be used repeatedly. System does not need a security channel. It is easy for the participants to join or leave system dynamically, and all the secrets can be recovered in one time.
-
Computer Engineering. 2010, 36(20): 155-156. https://doi.org/10.3969/j.issn.1000-3428.2010.20.054
This paper presents a forgery attack on the threshold signature scheme proposed by Zhang Youyi et al that can resist conspiracy attack. Everyone can generate a valid threshold signature, which proves the scheme is not secure. So an improved scheme is proposed to overcome the weakness of the signature scheme, and its validity and security are proved.
-
Computer Engineering. 2010, 36(20): 157-158. https://doi.org/10.3969/j.issn.1000-3428.2010.20.055
The researches on combination of identity, threshold proxy signature and blind signature are rare presently. This paper proposes an ID-based threshold proxy blind signature scheme by combining proxy signatures, threshold signatures, blind signatures and using bilinear pairing on elliptic curve. It solves the problem that potency is too centralized in proxy signature, and realizes the anonymity by blind signture. Analysis shows that the scheme is easy to carry out and has high robustness, and it is suitable for application in practice.
-
Computer Engineering. 2010, 36(20): 159-160. https://doi.org/10.3969/j.issn.1000-3428.2010.20.056Aiming at the different characteristics of initialization process and the key stream generation of My Array Generator(MAG) algorithm, this paper gives two kinds of forward inversion attack algorithm based on known plaintext assumption. For the 80 bit and 128 bit keys, it can recover 40 bit and 32 bit key respectively with 128 consecutive known key stream byte and the computing complexity O(214). Simulation results show that the average attack time is about 9 min, and the attack success rate is 1.
-
Computer Engineering. 2010, 36(20): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2010.20.057Aiming at the problem of premature convergence and insufficient diversity in traditional immune algorithm, this paper proposes a multi-objective optimization immune algorithm based on knowledge domain. The algorithm selects the elite solution by initializing knowledge domain, self-adaptive updates knowledge domain border by using this elite solution to maintain the balance between the convergence and diversity. Test results show that the algorithm has great advantage on convergence, diversity and run time.
-
Computer Engineering. 2010, 36(20): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2010.20.058This paper offers image layered matching algorithm based on the median. It figures out the median of each image, constructs the Gauss-Laplace matrix corresponding to every lay respectively, conceives the related-matrix being true of the match level which accord to each feature point by the result of SVD analysis. It obtains the matching result of the entire image by the feature points matched. Experimental results demonstrate the feasibility and effectiveness of the approach.
-
Computer Engineering. 2010, 36(20): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2010.20.059This paper proposes a method of probabilistic semi-supervised learning in order to improve accuracy of classifier and reduce cost of labeled sample. Research is based on the method, and classification results are compared with that based on naive Bayesian full-supervised learning. This paper uses remote sensing image data as the training and test sample set. Experimental results show that when the proportion of labeled sample to unlabeled sample is between 1:2 and 1:9, classification based on semi-supervised learning can get higher accuracy than that based on full-supervised learning using much less labeled sample.
-
Computer Engineering. 2010, 36(20): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2010.20.060Two models of classifier-fusion systems designed by genetic algorithms are proposed. 1st model utilizes disjoint feature subspaces, whereas 2nd one withdraws the restriction. Through the experiments, the two models are compared against single classifiers. Results show that, the two classifier-fusion systems yields better classification accuracy against the two single classifiers, and 1st model, which utilizes disjoint feature subspaces, can help improve the classification of high-resolution remote sensing with significant feature correlation.
-
Computer Engineering. 2010, 36(20): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2010.20.061Aiming at the problem of traditional genetic algorithm is easy to involve in local optima, this paper presents a self-adaptive genetic algorithm based on evolvability. The individual evolability as a parameter is put into the nonlinear fitness function which dynamically adjustment with the evolution algebra, and it adjusts dynamically the crossover and mutation probability to runaway the local optima. Experimental results show that this algorithm can improve the survival probability of the individuals with better evolvability but worse fitness, and enhances population diversity and search efficiency.
-
Computer Engineering. 2010, 36(20): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2010.20.0623D face reconstruction algorithms require more than one image to realize reconstruction and their efficiency is low. Aiming at the problems, this paper proposes a 3D face reconstruction algorithm based on single frontal photo. It uses Thin Plate Spline(TPS) function to build 3D face model by establishing the point-to-point correspondence among 3D faces in the database, so that an average 3D face model is built. It uses Levenberg-Marquardt Algorithm(LMA) to optimize the shape coefficients. The input image is projected orthogonally to the 3D shape to generate the face texture. Experimental results show that the method can generate realistic 3D faces efficiently.
-
Computer Engineering. 2010, 36(20): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2010.20.063
To realize multi-sensor tracking for maneuvering target state, this paper presents a multi-sensor fusion algorithm based on DSmT and particle filtering. On the basis of observation date which is delivered by multi-sensor and filtered by particle filters. It chooses DSmT as the combining tool. The observation data is transformed into the elements and masses of the frame of discernment, and gets the finally result. Experimental results show that this algorithm can reduce distance error and improve tracking accuracy, and the appropriate computational complexity can satisfy the demand of fusing on-line.
-
Computer Engineering. 2010, 36(20): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2010.20.064A natural feature recognition method based on machine learning is proposed for 3D registration in augmented reality application. This method increases the accuracy of key-points recognition and moves the computational burden from runtime matching to offline training by substituting specific classification for nearest-neighbor searching. Robust camera tracking and pose estimation can be obtained by the similarity of these matched key-points and the homography matrix. Experimental results demonstrate that this method is suitable for real-time application and is stable against illumination change, occlusion and perspective effect.
-
Computer Engineering. 2010, 36(20): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2010.20.065
In order to avoid the obstacles in the surrounding environment, some changes of formation style should be applied on the traditional-controlled formation. Those changes of formation can not satisfy those situations in which high degree of accuracy is required, like joint transportation. This paper introduces a strategy of rigid-formation control which regards the whole formation as a virtual unity. Theoretical analysis and experimental results show that this strategy can successfully smooth the track during avoiding obstacles, increase the degree of formation-maintain accuracy, and solve the contradiction between avoiding obstacles and keeping formation.
-
Computer Engineering. 2010, 36(20): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2010.20.066This paper proposes a Multi-Objective Artificial Physics Optimization(MOAPO) algorithm to solve multi-objective optimization problem. By adopting the method of setting random power for each object to get the global object, both the global best and worst objects fitness in multi-objective optimization problem are found, so that searching for Pareto optimal set of multi-objective optimization problem is implemented by using APO algorithm. Three benchmark functions are tested to compare the performance of MOAPO with MOPSO. The results show that MOAPO is effective for solving multi-objective problems with an excellent diversity.
-
Computer Engineering. 2010, 36(20): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2010.20.067This paper makes FIRA SimuroSot 5v5 game simulation platform as the background, for the problem that how to maximize the threat of attack in strategy, proposes a selection method of the best offensive player and offensive point based on prediction models. It builds the robots and the ball motion models, according to the established prediction models to determine the effective attack time, which can calculate the offensive players and offensive points. It carries out a detailed threat of attack-degree evaluation to each offensive player and offensive point and selects the best offensive player and the best offensive point. Simulation tests verify the validity of the method.
-
Computer Engineering. 2010, 36(20): 194-197. https://doi.org/10.3969/j.issn.1000-3428.2010.20.068
This paper analyzes Chinese character structure feature and evolution, combines the character recognition process together on the basis of Chinese character database and changing in recognition target, researches and comprises the advantages, disadvantages and the application range of five different kinds of Classification recognition method such as Bayesian method, quadratic discriminate function approach, Markov model, neural network classifier and Support Vector Machine(SVM). Results shows that Chinese character recognition method including recognition should be improved on the aspects of target, feature extracting and train set preparing.
-
Computer Engineering. 2010, 36(20): 198-199. https://doi.org/10.3969/j.issn.1000-3428.2010.20.069Aiming at the disadvantages such as prematurity in Particle Swarm Optimization(PSO) algorithm because of the decrease of swarm diversity, an improved PSO algorithm named GLBest-PSO(Global-Local Best PSO) is proposed combining the global best and local best model. The algorithm incorporates global-local best inertia weight and global-local best acceleration coefficient to simplify the velocity equation and the performance of the algorithm is improved. It is used in the reactive power optimization in power system. Simulation results show that its average transmission loss is lower, with better optimization performance and smaller area of optimized transmission loss values.
-
Computer Engineering. 2010, 36(20): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2010.20.070The Itti model has a limitation on choosing features. Inspired by the visual attention results in the psychology, this paper proposes a computational model of visual attention. Based on the segment-based stereo matching which using belief propagation and a self-adapting dissimilarity measure, the depth information is computed. Intensity, color, orientation and depth information are deployed and create the saliency map. The saliency map is deployed to the FOA through inhibition of return and WTA mechanism. Experimental results show the model effectively reflects the influence of stereo vision to attention, and the computational result is more consistent with the human vision.
-
Computer Engineering. 2010, 36(20): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2010.20.071An improved constrained multi-objective Particle Swarm Optimization(PSO) algorithm which adopts constraint handling technology based on distance measures and adaptive penalty functions is proposed. The proportion of feasible solutions is used to keep the balance between objective function and constraints and improve the boundary searching capability of the algorithm. A new k nearest neighbors crowding density is defined to maintain the diversity of solutions. It selects the global optimal particle through the combination of crowding density and roulette selection. Experimental results demonstrate that the algorithm is efficient for solving constrained multi-objective optimization problems
-
Computer Engineering. 2010, 36(20): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2010.20.072
This paper proposes a new approach to improve collaborative filtering recommendation. It applies the attitude-behavior relationship theory in psychology to predict the users’ rating using the Web usage data and adopts the predicted rating in collaborative filtering algorithm to generate recommendations for users. It verifies the prediction model, and compares the method to traditional collaborative filtering algorithm which only records the users’ clicks as their interests. Experimental results demonstrate that the method is more effective at recommending items for users than the traditional algorithm.
-
Computer Engineering. 2010, 36(20): 209-210. https://doi.org/10.3969/j.issn.1000-3428.2010.20.073
Basedon the directed acyclic graph structure of gene ontology, this paper proposes a novel method to measure the semantic similarity of gene ontology terms. By calculating the common ancestors of two terms and the disjunctive ancestors according with the condition, the average information content of disjunctive ancestors and the average information content of the two terms are obtained. The semantic similarity of two terms is the ratio of the average information content of disjunctive ancestors to the average information content of two terms. Experimental results show that the method has high accuracy.
-
Computer Engineering. 2010, 36(20): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2010.20.074The inconvenience of product selection and function realization can be solved at a certain extern when the method of designing real-time drive is mastered. It introduces the developing flow of PCI bus drive in RTX real-time environment. The following functions of real-time drive design are explained including finding device, getting bus message, mapping address, initial configuration, serving interrupt and so on. The real-time drive application in a certain RTX real-time system proves its advantage.
-
Computer Engineering. 2010, 36(20): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2010.20.075Metastability emerges from designing the interface between ARINC659 and PCI9054 because of the two different clocks. This paper describes the mechanism of the metastability, gives conditions for reducing metastable produce, and proposes achieving control signal transmission by synchronizer and data transfer by Gray code + FIFO. With PCI9054 interface signal timing, the paper designs the bus interface module, and implements the interface design with the Verilog language. Result shows that asynchronization FIFO solves cross-clock data transfer between ARINC659 and PCI9054.
-
Computer Engineering. 2010, 36(20): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2010.20.076In order to improve the efficiency and quality of meteorological services, the provincial system of ground automatic weather station based on Rich Internet Applications(RIA) is exploited. The system making full use of Flex Builder to develop WebGIS graphical interface based on Flash plug-in unit achieves the function of data management through the Java technology, such as query, analysis and statistics etc., as well as performance with form, histogram, stain maps and so on. Due to the overall design of progressive thinking, a high level of human-computer interaction, as well as the cross-browser and cross-platform features, this system can promote a certain value in practical application.
-
Computer Engineering. 2010, 36(20): 220-221. https://doi.org/10.3969/j.issn.1000-3428.2010.20.077The gun recoil simulation based on one-dimensional theory simplifies the hydraulic resistance coefficient as a fixed value. The method of handling makes the hydraulic resistance not accord with the actual conditions. Aiming at this problem, a new method of collaborative simulation based on Matlab/Fluent is proposed. The method can correct the mistake of one-dimensional model. The two-dimensional model of recoil brake which is accord with the actual structure is built. Gun recoil movement is calculated with Matlab and fluid pressure is calculated with Fluent. Through data exchange mechanism based on external file interfaces, the simulation of gun recoil dynamic process is realized. Comparing a calculation example with the firing test, the results prove this method is feasible and valid.
-
Computer Engineering. 2010, 36(20): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2010.20.078For achieving constant pressure water supply and improving the uniformity of irrigation and time-based auto irrigation, a PC-PLC-based auto-control system for green house micro-irrigation is presented, and the hardware and software design of the system are discussed. Based on the research of time control model of multi-road multi-period irrigation schedule, a self-adaptive configuration rotational irrigation strategy is designed to avoid pressure collision and pressure loss, and PID close-loop control technology is employed to achieve constant pressure water supply based on variable frequency drive technology. Application results indicate that this system has good robustness and high automation level, and can satisfy the demand of scientific irrigation of well-timed and right amount.
-
Computer Engineering. 2010, 36(20): 225-228. https://doi.org/10.3969/j.issn.1000-3428.2010.20.079Technologies of Design for Manufacturability(DfM) help IC designers to get the information of manufacturability of an IC design as early as possible to reduce turn-around-time. This paper proposes a new DfM model. One or more convolution kernels are used to describe the relationship between the pattern and contour. The modeling is solved by using steepest descent method, and only pairs of pattern and contour are needed. Experimental results show that the model can predict contour accurately with less than 1.8% differences to lithographic simulation result.
-
Computer Engineering. 2010, 36(20): 229-231. https://doi.org/10.3969/j.issn.1000-3428.2010.20.080This paper uses a formal analysis method to analyze the publish/subscribe real-time performance by PRISM model checker, which is based on the queuing theory. Experimental results show that publish/subscribe has better performance compared with traditional communication mode in terms of message response time and message transmission reliability. The experimental model and method not only can help improve publish/subscribe, but also have effect on adjusting publish/subscribe system parameter configuration.
-
Computer Engineering. 2010, 36(20): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2010.20.081
Some models of events in the campaign process of multichannel surface to air missile weapon system are built, and based on them, the campaign simulation system of multichannel surface to air missile weapon system is founded with Arena which is a visual environment for modeling and simulation. This simulation system is applied to evaluate the multichannel surface to air missile weapon system’s capability of anti-airplane saturation attack. The result proves that the simulation is valid.
-
Computer Engineering. 2010, 36(20): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2010.20.082Aiming at the problem that Radio Frequency Identification(RFID) tag has short storage space and higher data repeatability, this paper presents an improved RFID tag data compression algorithm based on the LZW. The algorithm uses multi-tree storage structure to enhance data compression speed and improves the operating method for threshold determination to avoid the waste of storage space. Experimental results show that compared with other algorithms, this algorithm has higher performance in compression time and efficiency.
-
Computer Engineering. 2010, 36(20): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2010.20.083This paper describes the principle and the working process of the CAPS-OC terminal application on ocean data buoy’s observation system. Design and implementation of CAPS-OC terminal control system software and the important technology of the multi-serial chip are expounded in detail. Through intercommunication of CAPS-OC terminal on large mooring buoy observation system and location experiment, result shows that CAPS-OC terminal and core control software have well stability and reliability.
-
Computer Engineering. 2010, 36(20): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2010.20.084Tag collision problem is a key issue in Radio Frequency Identification(RFID) system. The efficient algorithms for solving this problem usually deal with fix-length of tag encoding. For solving this problem with unfixed-length of tag encoding, a fast anti-collision algorithm called U-algorithm is presented. The U-algorithm is also of the advantages of binary tree algorithms. Simulation implementation experiments show that the proposed algorithm has the efficient identification ratio of 41.67%.
-
Computer Engineering. 2010, 36(20): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2010.20.085Xen does not consider the impact of CPU intermittent faults. On the basis of this, this paper builds a time model for simulating intermittent fault in Xen. In the model, domains in unmodified Xen system will crash immediately. Therefore the paper proposes a self-adaptive strategy which does CPU scheduling in Xen. It spontaneously traces the change of CPU status and migrates virtual processors mapped in faulty CPUs to available CPUs. Experimental result shows that the virtual machine can keep running steadily and the performance of workloads in Xen reduces smoothly while intermittent occurs frequently.
-
Computer Engineering. 2010, 36(20): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2010.20.086This paper analyzes operation modes of enterprise IT Service Management(ITSM) and discusses the collaboration scenario for ITSM. On the basis of this, this paper proposes an innovative scheme which comprehends a methodology and a tool to support collaboration in IT service management based on the worksheet management process and delegation mechanism in configuration management. Three enterprises are chosen for pilot run, result shows that the scheme can provide a good support for distributed collaboration in ITSM.
-
Computer Engineering. 2010, 36(20): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2010.20.087
Automatic parallelization has limitations on the parallelizing capabilities and the scope of applications, while the interactive parallelization method makes up the deficiencies. This paper presents an interactive parallelization system named ZJU Interactive Parallelizing System(ZIPS), and describes the mechanism in detail. The system uses a computation-driven algorithm as the basis, obtains the program information through the powerful interaction interface, combines the technology of automatic parallelization, and finishes the source to source transformation for two different computations. Experiments show that the method can achieve good performance.
-
Computer Engineering. 2010, 36(20): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2010.20.088This paper presents a BitTorrent(BT) file transmission control method based on file pollution. The method uses combination of file index pollution and data pollution to disturb the establishment connections of the peers and the transmission of data for special download tasks. Experimental results show that this method can efficiently prolong the transmission time or destroy the information exchange and achieve the aim of transmission control.
-
Computer Engineering. 2010, 36(20): 256-258. https://doi.org/10.3969/j.issn.1000-3428.2010.20.089
The wireless netowrk position technologies based on ZigBee are developing rapidly in recent years, but in pratical application their precisions are also greatly affected by signal fluctuations caused by the multipath effect, human interference and so on. For the signal fluctuations in pratical application, the paper uses a vibration sersor to judge the motion state of position terminal, and estimates the motion path and direction by stable position fingerprints, finally searches for the nearest neighbors in the neighborhood of the estimated path, and gets the position result. Experimental results show the method weakens the affection caused by signal fluctuations, the precision statistics is about 2 m to 6 m.
-
Computer Engineering. 2010, 36(20): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2010.20.090Aiming at the low precision and efficiency of common location algorithm based on coordinate conversion, this paper proposes a location algorithm based on perspective transformation principle. It defines a homography matrix which uniquely reflects space mapping relationship between points by the coordinate information of four original locations. After location, coordinate conversion can be finished through simple calculating by using this homography matrix. Experimental results show that this method is stable.
-
Computer Engineering. 2010, 36(20): 262-264. https://doi.org/10.3969/j.issn.1000-3428.2010.20.091This paper uses active prode for fault management of distributed applications. According to the features of distributed applications, probe set selection algorithm based on cost-benefit balance is proposed in the fault detection phase, and diagnosis probe selection algorithm based on minimum greedy search and probe cost is proposed in the fault diagnosis phase. Experimental results show that the number of probes, detection time and detection traffic have significant improvement.
-
Computer Engineering. 2010, 36(20): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2010.20.092This paper describes the acceleration of hmmsearch by exploiting fine-grained designs based on FPGA. It exploits data reuse schemes by making use of the method of fetching, slip windows and data transmition and utilizes pipeline in the matrix cell. Experimental results show the performance can reach to 3.6 GCUPS, which is nearly 235 speedup over that of CPU. One PE calculating performance improves 34% over the fastest FPGA accelerator of the same kind.
-
Computer Engineering. 2010, 36(20): 268-271. https://doi.org/10.3969/j.issn.1000-3428.2010.20.093
Based on the space-time eigenstructure of signals, an improved space-time Direction Of Arrival(DOA) estimation matrix method is proposed to estimate the high-resolution 2-D DOA of narrowband signals. The method obtains two DOA matrices through creating another sub array, which is the primary sub array shifted down X axes. Because these two matrices are different in angle ambiguity curves, the method can get accurate DOA; therefore advantages of the traditional space-time DOA matrix method, such as automatic parameter alignment and no need of 2-D search, are still available. Simulation results show that the method is effective.
-
Computer Engineering. 2010, 36(20): 272-275. https://doi.org/10.3969/j.issn.1000-3428.2010.20.094Based on discussing the history of advancement to building the Tree Of Life(TOL) using genetic and genomic information, effective strategies and methods for the construction of the tree of life, this paper carries out business process analysis and application design. It implements a phylogenetic analysis platform for the land plants based on this analysis. The platform extracts molecular data from the international public databases in batch, which is automated acquisition, cleaning function for users to understand the situation of peer data. The process of phylogenetic reconstruction includes several public modes and tools, such as batch extraction, multiple sequence alignment, cleaning & editing, tree reconstruction, phylogeny evaluation and visualization. All these procedures demand a number of interactive interfaces for phylogenetic tree automatic generation and decision-making aids experiment.
-
Computer Engineering. 2010, 36(20): 275-276. https://doi.org/10.3969/j.issn.1000-3428.2010.20.095
In allusion to the storm surge system’s requirement: it is necessary to figure out the shortest path from the disaster area to multi-settlements, then to evacuate the victims based on the number of disaster victims and the capacity of the settlements, this paper presents two improvements of Dijkstra algorithm, including sorting the shortest paths and evacuating to multitargets. An emulation is carried out based on Matlab, and it turns out that the improvement of the algorithm is effective and feasible, which can reduce the times of figuring out the path of evacuating to multitargets from several to one.
-
Computer Engineering. 2010, 36(20): 277-280. https://doi.org/10.3969/j.issn.1000-3428.2010.20.096This paper introduces the Service-Oriented Architecture(SOA) as IT architecture for enterprises, and proposes a Business Process Management Model for Web Services(BPMM4WS) with the consideration of three key factors, including process, information and collaboration in the model implementation. By separating the process of modeling and implementation, the mechanism of automatic composition and scheduling services are proposed which enables the dynamic, automatic, quick process integration. Finally, an example of inter-organizational purchase process is given to show the model functions.
-
Computer Engineering. 2010, 36(20): 281-282. https://doi.org/10.3969/j.issn.1000-3428.2010.20.097
Focusing on the problem of effectively organize and retrieve the distributed massive remote sensing images, this paper presents a well extensible remote sensing catalogue data model based on the remote metadata standard draft which is proposed by the Federal Geographical Data Committee(FGDC). A distributed remote sensing images retrieval algorithm is designed based on the proposed catalogue data model. It accomplishes a remote sensing data catalogue and retrieval system which is successfully applied to a massive data management system.
-
Computer Engineering. 2010, 36(20): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2010.20.098Low-Density Parity-Check(LDPC) codes are typical of preeminent performance approaching Shannon’s capacity limit. This paper studies the LDPC codes min-sum decoding algorithm, and a min-sum algorithm in QPSK modulation based on integer operation is proposed for decoding LDPC codes. All the variables are fixed length integers in this algorithm, so it is very convenient for hardware implementation. Simulation results show that its performance is close to that of sum-product algorithm whose variables are high precision floating point numbers.
-
Computer Engineering. 2010, 36(20): 286-290. https://doi.org/10.3969/j.issn.1000-3428.2010.20.099Taking the Small Wild Goose Pagoda in Tang Dynasty as the case, aiming at the problem of 3D reality-based modeling and virtual exhibition for culture archaeological sites, this paper proposes a scheme of 3D digital data acquisition of the large archaeological sites by combining the technologies of 3D laser scanning of the large scene and the digital photography. Based on the laser-synchronized visual image of the ancient buildings, it offers a method of 3D reality-based modeling from real data with the adoption of the local texture mapping, and introduces the systematic architecture, technology roadmap and all key technologies of 3D desktop virtual walkthrough system based on GIS and virtual reality technology for the large archaeological sites. Application proves that the system can improve 3D virtual exhibition effect of cultural archaeological sites.
-
Computer Engineering. 2010, 36(20): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2010.20.100Radio Frequency Identification(RFID) reader usually works at the invariant output power, and thus causing the unnecessary consumption of electrical energy. Aiming at this problem, this paper presents a self-adaptive adjusting strategy for RFID reader power based on fuzzy control theory. The strategy adopts corresponding fuzzy control algorithms to adjust dynamically the output power of RFID readers based on difference of RFID tag number timely. Simulation test result shows that the strategy can reduce the consumption of electrical energy.
2024
Volume 50 No 3
Volume 50 No 3
(Started in 1975, Monthly)
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428