05 September 2011, Volume 37 Issue 17
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Computer Engineering. 2011, 37(17): 1-6. https://doi.org/10.3969/j.issn.1000-3428.2011.17.001
This paper proposes a method of modeling the reconfigurable core cell based on stochastic Petri net. For its structural properties, such as reachability, boundedness and safety, it presents the logical correctness verification. As to its performance properties, such as stable probability, transition probability and throughput rate, it presents the quantification analysis. This paper discusses the effects between dynamic reconfiguration time and the finished time of computing task under three different conditions. Analysis result shows that the shorter dynamic reconfigurable time is, the shorter task complete time is.
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Computer Engineering. 2011, 37(17): 7-10. https://doi.org/10.3969/j.issn.1000-3428.2011.17.002
This paper proposes a method of multi-view face features localization. The face is located by AdaBoost detector and the search ranges of the face features are determined. The candidate eye, nose and mouth regions are found by the improved Support Vector Machine(SVM) detectors trained by large scale multi-view face features examples, which use the brow-eye and nose-mouth features. The candidate eye, nose and mouth regions are filtered and merged to refine their location on the multi-view face. Experimental results show that the method has very good accuracy and robustness to the face features localization with various face post and expression in the complex background.
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Computer Engineering. 2011, 37(17): 11-14. https://doi.org/10.3969/j.issn.1000-3428.2011.17.003
Aiming at the shortcoming of the compressed edge fragment sampling algorithm, a new method is proposed, called Overlapping Hash Fragment(OHF) Probabilistic Packet Marking(PPM) method. The new method reduces the computational complexity during reconstruction by constructing 4 bits hash relationship between the adjacent IP fragments without increasing the marking amounts. And the new method improves the false alarm rate. Simulation experiment in the NS2 show the validity of the method.
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Computer Engineering. 2011, 37(17): 15-18. https://doi.org/10.3969/j.issn.1000-3428.2011.17.004
To solve automatic predicate-verb choosing for argument, this paper gives semantics preference method based on Minumum Description Length(MDL) and Latent Semantic Clustering(LSC). MDL is used to calculate of each verb-noun pair. The probabilities of a verb preferring for a noun P(v,n) is computed based on LSC model and EM is used to evaluate the parameters. For the same verb-noun pair, the sum of and P(v,n) is considered to represent the association between the verb and the noun. Experiments show the F1 reaches 85.26%, and it is better than MDL or SCL methods.
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Computer Engineering. 2011, 37(17): 19-22,28. https://doi.org/10.3969/j.issn.1000-3428.2011.17.005
Considering the outer classes and inferior problem in Kernel Maximum Scatter Difference(KMSD) method, a new method of face recognition based on Kernel Principal Component Analysis(KPCA) and Fuzzy Maximum Scatter Difference(FMSD) is developed. The KPCA can be benefit to develop the nonlinear structures features in faces. Selecting the eigenvectors that between-class scatter is greater than within-class scatter after projection as optimal projection axis. Distribution information of samples is represented with fuzzy membership degree in the FMSD. It uses the nearest neighbor classifier for face recognition. Experimental results on ORL and YALE face databases show the KFMSD is better than KMSD method.
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Computer Engineering. 2011, 37(17): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2011.17.006Considering the insufficiency of clustering speed which exists in the selecting the initial centroid of Bisecting K-Means(BKM) clustering algorithm, the idea of selecting the two patterns with distance maximum as the initial cluster centroid is implemented. An in-depth study and analysis is carried out on how to accelerate clustering in clustering system. According to the characteristics of BKM, the parallelism algorithm based on data parallelism and symmetric data-partition is put forward. Experimental results show that the improvement of algorithm gets ideal speedup performance and efficiency.
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Computer Engineering. 2011, 37(17): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2011.17.007To solve the problem that the ability to describe roles is limited, this paper imports role expression in current description logic SHIQb to describe roles, forms description logic SHIQb. The relevant definitions are given, and proves that if all the role expressions of the knowledge base are safe role expressions, then the complexity of the reasoning with KAON2 reasoner is remain in Polynomia Time. From this point, an algorithm is put forward to check whether the role expression is safe.
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Computer Engineering. 2011, 37(17): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2011.17.008Addressing the trustworthiness of internetware, this paper proposes an approach to verify business consistency of internetware evolution. The approach gives the semantic interpretation of system described by XYZ/ADL and defines the transformation rules from XYZ/ADL to interface automata, and presents three rules for verifying system business consistency. An example is incorporated to instantiate the application of these rules. Spin model-checker is used to prove that the approach can be used to verify the business consistency of internetware evolution.
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Computer Engineering. 2011, 37(17): 32-34,37. https://doi.org/10.3969/j.issn.1000-3428.2011.17.009Aiming at the low effectiveness of the static inference control method based on data cube in the On-line Analytical Processing(OLAP) system, this paper proposes the dynamic inference control method based on data cube to improve the effectiveness and to deal with problems of on-line real-time inquiry. The method analyzes the inference and prevents the occurring of inference threats of queried cuboids. The method can dynamically return an accessible set of cuboids. Experimental result shows the improvement of the effectiveness of the inference system and it has the same security as the static inference control method.
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Computer Engineering. 2011, 37(17): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2011.17.010This paper proposes a offline skewed schedule algorithm for variable-length data items to minimize the access time in data broadcast. Based on the square-root-rule in data broadcast, the frequency and instance spacing of each data item are calculated, according to these, the broadcast sequences are generated. Experimental results show that the access time achieved by this algorithm is nearly the optimum with the average deviation percentage of access time at about 6%.
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Computer Engineering. 2011, 37(17): 38-39,43. https://doi.org/10.3969/j.issn.1000-3428.2011.17.011Discernibility ability index DI(a) of decision table is defined, some properties about DI(a) are presented. Concept of quasi-equivalence class is defined, a relative reduct algorithm about decision table is proposed based on the discernibility ability index. The algorithm uses divide and conquer strategy to reduce research space by replacing discernibility element with attribute a. Experimental results show that the algorithm has better efficiency and can obtain all or majority of reducts.
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Computer Engineering. 2011, 37(17): 40-43. https://doi.org/10.3969/j.issn.1000-3428.2011.17.012This paper researches and realizes the software package building system for Kylin Operating System(OS). The system has a large number of deficiencies, such as load imbalancing and poor usability, aiming at these shortcomings, the load balancing schedule algorithm is implemented to optimize the system schedule policy based on total available system resource. Experimental result proves that the algorithm significantly improves the building system resource utilization, enhances performance, improves system availability and efficiency, which can generate OS release with high-quality.
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Computer Engineering. 2011, 37(17): 44-45,57. https://doi.org/10.3969/j.issn.1000-3428.2011.17.013The workflow merging requirements are formally described through relationship-rules and activity-rules. Moreover, an algorithm to check conflicts in the merging rule set is proposed based on the reachability relationships. This algorithm can find out combinations of conflict merging rules from the given rule set through tracing new reachability relationships and corresponding deriving rules, which provides the basis for the adjustment of the merging rule set. Concrete example analysis shows the effectiveness of the proposed algorithm. This research provides support for the successful deployment of workflow merging.
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Computer Engineering. 2011, 37(17): 46-48,60. https://doi.org/10.3969/j.issn.1000-3428.2011.17.014The binned density estimation which is designed for very large datasets and based on the gravity center of the data points in a grid is extended to data stream applications. When introducing a density decaying scheme, it is revealed that the closeness of such estimators which substitutes the center of a grid with the gravity center of the data points is bounded. As a result, an algorithm for multidimensional evolution data streams is proposed. Experimental results show the algorithm can capture the evolving behaviors of the data stream in real time with enough accuracy.
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Computer Engineering. 2011, 37(17): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2011.17.015Since relational expressions are difficult to execute one-to-many data transformation, the paper expresses one-to-many transformation by extending relational algebra, the recursive query and the table function should be employed to realize unbounded one-to-many transformation for producing one or several output tuples over every input tuples. Recursive queries create original results to obtain result sets by recursion and return final result sets. Table functions declare variable sets and employ a procedure body and cursor to access tables, iterative output tuples. Experiment analyzes different bounded and unbounded data transformations under different reference influencing factor. The results show the extension method improves performance observably.
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Computer Engineering. 2011, 37(17): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2011.17.016To remedy the defect of User Datagram Protocol(UDP) transmission in reliability, this paper proposes a design method using Finite State Machine(FSM) to control UDP transmission data. The different states are designed for the two sides of the transmission process. The format of data packet is conceived, each data packet carries the a command word to respect the different state. The data packet increased checking parity can ensure data consistency in transmission, to remove and recover a reserved keyword of data though the positive replacement and reverse replacement. It uses the automatic retransmission mechanism and the request retransmission mechanism to ensure normal and orderly transformation in the process of sending data, the data packet may become a variable-size packet thought increasing the header and the ender, which enhance the flexibility of data transmission. Experimental results prove the validity of the design method.
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Computer Engineering. 2011, 37(17): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2011.17.017Dynamic Source Routing(DSR) protocol based on improved discrete Particle Swarm Optimization(PSO) algorithm named P-DSR, is proposed. It introduces the conception of Intelligent Agent(IA), Ad hoc networks can solve the optimal routing problem using the 0-1 combinatorial optimization. It introduces the link stability factor as a PSO fitness function. Simulation results show that, compared to the original DSR protocol, P-DSR protocol can give lower end-to-end delay and higher packets delivery rate.
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Computer Engineering. 2011, 37(17): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2011.17.018In order to improve the accuracy of the hybrid search algorithm in the stream media system and reduce the message costs of traditional distribution algorithm, this paper proposes a resources popularity generation and distribution algorithm for stream media system. The generation algorithm based on global change rate uses the heart detection mechanism to detect the node’s passive left. The distribution algorithm uses Bloom filter to distribute the resources popularity. Compared to the traditional resource generation and distribution algorithm, the improved algorithm can truly reflect the network’s change and the message overheads in distribution process can reduce.
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Computer Engineering. 2011, 37(17): 61-63,66. https://doi.org/10.3969/j.issn.1000-3428.2011.17.019Scheduler can not work well for wireless channel which causes Channel Quality Indicator(CQI) parameter error when transporting for eNode B. A modified CQI-based packet schedule method for Long Term Evolution(LTE) is proposed. This method is based on the exponent smoothing forecast model and secondary moving average forecast method, combining priori parameters. Simulation result indicates that it can improve the throughput when scheduling.
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Computer Engineering. 2011, 37(17): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2011.17.020After analysis of Dynamic Source Routing(DSR) propocol, this paper proposes a Node State-based on DSR Protocol(NSBDSR) which is to be Wireless Mesh Network(WAM) network routing protocol. The node can only maintain the routing of nodes with itself. Using Network Simulator-2 for the simulation, the results indicate that NSBDSR protocol can help to effectively improve Quality of Service(QoS) performances, such as reducing the probability of route breaking and network delay, improving the routing traffic, packet loss rate, the data transmission efficiency.
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Computer Engineering. 2011, 37(17): 67-68,83. https://doi.org/10.3969/j.issn.1000-3428.2011.17.021This paper proposes a bandwidth allocation algorithm for Ethernet Passive Optical Network(EPON) based on dynamic grouping. It designs dynamic groups strategy, allocates Optical Network Unit(ONU) uplink bandwidth dynamically. Based on the loads of each ONU, it calculates each ONUs’ weight, and allocates bandwidth for each ONU. According to the change of load, it adjusts the groups’ numbers. Simulation results show that the proposed algorithm’s average packet delay time is lower.
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Computer Engineering. 2011, 37(17): 69-71,86. https://doi.org/10.3969/j.issn.1000-3428.2011.17.022By introducing the double-circle monitoring mechanism into Wireless Sensor Network(WSN), this paper proposes a target tracking method based on quadrant location. It selects the high-relative nodes based on the relation of the nodes positions, locates the mobile targets which are rapidly detected by the outer circle and accurately located by the inner circle, and uploads the mobile target track to the sink simultaneously. Theoretical analysis and experimental results show that the method can reduces the power consumption of WSN and increases the locating precision.
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Computer Engineering. 2011, 37(17): 72-74,89. https://doi.org/10.3969/j.issn.1000-3428.2011.17.023To support reliable file transfer in deep space communication environment, this paper studies the transporting mechanism of asynchronous NAK mode of CCSDS File Delivery Protocol(CFDP). According to the dynamic adjustment timer method, this paper proposes an improved algorithm of CFDP latency estimation. In asynchronous NAK mode under bandwidth constrain, the algorithm through the predicted one-way delay to judge the network condition, NAK trigger and timer rule is optimized. Analysis results in NS2 show that the file delivery time of this algorithm is less and the throughput is larger.
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Computer Engineering. 2011, 37(17): 75-77,92. https://doi.org/10.3969/j.issn.1000-3428.2011.17.024The parameter setting for Random Early Detection(RED) queue management algorithm depends on the user’s experience and its related theoretical guidance exists some defects at present. A comprehensive analytical method is proposed to set the RED parameters. Through adopting mathematical expectation method, steady-state behavior of discrete model of the TCP/RED congestion control mechanism is analysed, and the relationship between the network in the steady-state expectations and RED parameters are derived. Simulation results show that the method can provide an accurate and efficient method of RED parameter setting.
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Computer Engineering. 2011, 37(17): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2011.17.025Hummingbird algorithm needs small area for implementation and low power, so it is suitable for safety encryption of Radio Frequency Identification(RFID) tags. This paper uses SMIC 0.13 μm to implement Hummingbird algorithm. By reducing the unnecessary clock toggling and data toggling, it reduces dynamic power. Simulation experimental results prove that Hummingbird algorithm can meet the requirements of hardware cost, power consumption and response time.
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Computer Engineering. 2011, 37(17): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2011.17.026As the shortcomings of poor security and inefficient communication of AODV routing protocol in the wireless Ad Hoc network, this paper proposes an authenticated routing protocol based on small world model. The new protocol builds on the small world graph’s advantages of searching path fast, and reduces the burden of the network brought by AODV protocol while improving the security of communication, without querying information by broadcasting routing. Analysis results show that the method of the scheme is effective.
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Computer Engineering. 2011, 37(17): 84-86. https://doi.org/10.3969/j.issn.1000-3428.2011.17.027A novel recoverable semi-fragile digital watermark algorithm in multiwavelet domain is proposed. The algorithm employs a reduced halftoned image as watermark and embeds it in the multiwavelet domain through adaptive quantization index modulation. While the watermarked image is tampered unauthorizedly, it compares the halftoned tampered image and the magnified extracted watermark to localize the tampered areas automatically without initial bi-watermark. Experimental results show that the proposed algorithm is effective for smaller area tamper localization and recovery.
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Computer Engineering. 2011, 37(17): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2011.17.028This paper proposes a trust model for P2P network. By distinguishing direct trust and indirect trust, recommend trust value is got according to the past successful recommendation number but not direct trust, which resists behaviors that some Peers with high direct trust cheat others. In order to avoid non-malicious nodes to be isolated out of the network because of failure to offer services, incentive and trust construction mechanisms are introduced, which improves trust value of non-malicious nodes regularly, so that those nodes can rejoin the network and fault-tolerance of the network is strengthened. Experimental result shows that the model can better protect non-malicious nodes and isolate bad nodes, so that the network has better robustness.
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Computer Engineering. 2011, 37(17): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2011.17.029Combining the advantages of proxy signature and ring signature, this paper proposes a new efficient ID-based proxy ring signature scheme based on bilinear pairings, and proves that it satisfies the security requirements of a proxy ring signature scheme, which contains distinguishability, unforgeability, unconditional ambiguity, undeniability and verifiability. At the same time, comparing with validity of the existing schemes, the computational cost of bilinear pairings which is the biggest is reduced from O(n) to O(1), the computational efficiency of the new scheme is obviously improved.
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Computer Engineering. 2011, 37(17): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2011.17.030This paper implements a S-box of Advanced Encryption Standard(AES) based on improved Masked Dynamic Differential Logic (MDDL)and semi-custom design flow. The experiment is finished three kinds of S-boxes which are based on different logic cell respectively and adapted the technology of TSMC0.18 μm. The ability against electromagnetic analysis of these S-boxes are evaluated. Experimental results show that electromagnetic emission produced by S-box based on the given defending logic is independent with input data. The new S-box can solve the problem of information leakage caused by the unbalanced dual signal, the capability of defending electromagnetic side-channel attacks of S-box is increased significantly.
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Computer Engineering. 2011, 37(17): 96-98. https://doi.org/10.3969/j.issn.1000-3428.2011.17.031This paper introduces Fuzzy C-means(FCM) clustering method, researches the methods of intrusion detection based on clustering analysis, and establishes a new model of network intrusion detection. The new model is included data pre-processor, clustering-component based FCM, Updater of clustering-center, and detection system, and improves the availability of intrusion detection system. Experimental result proves that the model can detect intrusion from the network connection data at a lower system false alarm rate and a higher detection rate.
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Computer Engineering. 2011, 37(17): 99-101,104. https://doi.org/10.3969/j.issn.1000-3428.2011.17.032Based on researching RSA signature algorithm and theory of cache timing attack, analyzing the implementation of RSA in OpenSSL0.9.8a, a caching timing attack method is given against the process of accessing initial table in the sliding windows algorithm. Simulation result demonstrates the cache timing attack can get more than 700 bit secret key from 1 024 bit private key and needs less samples compare to the timing attack based on statistic analysis.
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Computer Engineering. 2011, 37(17): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2011.17.033For the clash between robustness and invisible, this paper proposes a image watermark algorithm based on human visual characteristics of Discrete Cosine Transform(DCT) domain. In this algorithm, the watermark image to be embedded is transformed with Arnold transform, and the watermark image transformed is embedded into the host image’s Direct Current(DC) block of DCT domain in which the texture is more complexity. Experimental shows that the hidden of the method is better, and it can withstand a certain amount of cutting and compression coding types of attacks. It is a robustness method.
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Computer Engineering. 2011, 37(17): 105-107,110. https://doi.org/10.3969/j.issn.1000-3428.2011.17.034The database encryption scheme which supports the rapid inquires does not give the partition value extraction method of character and field, in order to solve the problem, this paper presents a database encryption storage and query based on optimal bucket partition. It chooses partition value based on optimal bucket partition, and the query and storage for encrypted string data is according to extract index value of agent encryption field and converse SQL statement of inquiry database. Experimental result shows that this scheme has higher first inquiry shooting and stable filtering efficiency, it can improve the encryption system performance.
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Computer Engineering. 2011, 37(17): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2011.17.035According to the safety certificateless signcryption model, this paper presents an efficient certificateless signcryption scheme with public verifiability based on bilinear pairing. There are four participants which are Key Generation Center(KGC), signcryptioner, designcryptioner and verifier. In order to improve the trust level of this cryptosystem, binding technique is adopted and the user’s secret value and public key is generated before KGC extracting the partial private key. The public verification only needs the message and ciphertext to validation party. Analysis result shows that the scheme enjoys desirable properties of confidentiality and existential unforgeability, computational cost is lower, and it is easy to realize.
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Computer Engineering. 2011, 37(17): 111-112,115. https://doi.org/10.3969/j.issn.1000-3428.2011.17.036This paper presents key management scheme based on identity and threshold secret sharing which is applies to Wireless Mesh Network(WMN). It uses threshold secret sharing to realize the system private key distributed generation, without the participation of the public key certificate, just registers on offline of Certificate Authority(CA), gets the user identity as a public key, which greatly reduces the user end computing and storage capacity needs, realizes the system and user private key of the periodic update. Analysis results show that the scheme has high safety and strong practical.
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Computer Engineering. 2011, 37(17): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2011.17.037Aiming to problem that independent and redundant attributes of high dimensional network data cause classification algorithms’ slow detection speed and low detection rate in network intrusion detection, this paper presents a feature selection method for network intrusion based on fast attribute reduction. It adopts Mutual Information(MI) between condition and label attributes of network data as measure to discard independent attributes, then a formula for measuring attribute importance based on positive region of rough set is applied as heuristic information to design a fast attribute reduction algorithm, which removes redundant attributes of network data to realize optimal selection of feature subset of network intrusion. Simulation experiment is done in KDDCUP1999. Result shows that the method is more effective in discarding independent and redundancy attributes and it has higher intrusion detection rate and lower false positive rate.
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Computer Engineering. 2011, 37(17): 116-118,135. https://doi.org/10.3969/j.issn.1000-3428.2011.17.038In view of some defects existing in current 3G authentication and key agreement protocols, a Security-enhanced Evolved Packet System-Authentication and Key Agreement(SE-EPS AKA) protocol is put forward based on Wireless Public Key Infrastructure(WPKI). The enhanced scheme realizes bidirectional authentication between the entities, protects the air interfaces and wired links, and resolves the problem of the user and access networks identity leakage. Meanwhile, the scheme can support digital signature to provide non-repudiation services. The formal verification result shows that the proposed protocol can satisfy the security requirements.
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Computer Engineering. 2011, 37(17): 119-121,139. https://doi.org/10.3969/j.issn.1000-3428.2011.17.039This paper discusses the trojan detection technique, and a detail contrast research of related characters is given. In order to provide trojan detection based on network data flow, a trojan identification method based on network communication fingerprint is broutht forward. The concept of communication fingerprint is introduced to expand the extension of the communication features. Through the experimental method the fingerprints information of trojan for each phase such as connection, control and file transfer can be highlighted. On that basis, a heuristic identification system for trojan based on network communication fingerprint is designed and implemented. Test results indicate that the system runs efficient and the results are accurate.
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Computer Engineering. 2011, 37(17): 122-123,142. https://doi.org/10.3969/j.issn.1000-3428.2011.17.040In order to make the current Single Sign-on(SSO) schemes effectively support the application of password synchronization, this paper designs a secure model with better expansionary. It uses Optimal Asymmetric Encryption Padding(OAEP) encryption algorithm to modify the plaintext and creates a digital certificate through RSA encryption algorithm. Hybrid Cryptograph Transfer Protocol(HCTP) is improved to make it better realize the transmission applications among the server, the client proxy server and the Certificate Authority(CA) institutions of transfer in SSO system. The realization of password synchronization test verifies the stronger instantaneity and the higher security in the password key compared with HCTP, which can effectively resist chosen-ciphertext attack.
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Computer Engineering. 2011, 37(17): 124-125,145. https://doi.org/10.3969/j.issn.1000-3428.2011.17.041Based on forward-security and the difficulty of solving discrete logarithm problems on the finite multiplicative group over the finite fields, a new proxy signature scheme is proposed. The scheme has the following characteristics: forward-security, unforgeability, undeniability, anonymous, etc. Besides the preceding characteristics, only the designated-receiver can validate the proxy signature. The new designed arithmetic successfully separates the power of proxy signature and the original signature. It analyzes the security of the scheme, and conclusion shows that the new designed scheme is more security.
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Computer Engineering. 2011, 37(17): 126-127,148. https://doi.org/10.3969/j.issn.1000-3428.2011.17.042Signature right can be delegated in proxy signatures. Ring signatures can achieve signing in an anonymous way. An ID-based proxy ring signature scheme is proposed based on the advantages of proxy signature and ring signature. In this scheme, not only the proxy signers are members of a ring, but also the original signers are extended into a ring, so the verifier can only be sure the rings which the original signer and the proxy signer belong to, but can not disclose the identity of the principal and the signer. Theoretical analysis shows that the scheme satisfies the properties of verifiability, unforgeability, anonymity and distinguishability.
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Computer Engineering. 2011, 37(17): 128-129. https://doi.org/10.3969/j.issn.1000-3428.2011.17.043The security of an ID-based authentication key agreement protocol is analyzed, the existence of security flaws such as redundant information, impersonation attacks and temporary secret information leakage attacks is point out. To overcome these security flaws, an improved protocol is proposed based on the original protocol, the security and the operating efficient of the improved protocol are analyzed under non-formalization. It shows that the improved ID-based authenticated key agreement protocol can satisfy all the security requirements of the key agreement protocol, which is with high efficiency.
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Computer Engineering. 2011, 37(17): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2011.17.044As the Particle Swarm Optimization(PSO) algorithm has some shortcomings of slow convergence and easy to fall into the local extreme value, this paper presents a improved particle swarm optimization with a new inertia weight. In different stages of the algorithm run, a corresponding formula is used to calculate the inertia weight. In Addition, adaptive mutation and linear-changed learning factor are introduced. The relational test simulation experiment is carried out. Experimental results show that the improved algorithm is feasible and efficient, it can solve norlinear problem.
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Computer Engineering. 2011, 37(17): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2011.17.045To efficiently resolve the high dimensional Web text classification problem, a novel classification algorithm is proposed in this paper on the basis of manifold learning. The algorithm can explore and preserve the inherent structure on high dimensional Web text space, and the classification and predication in the lower dimension feature space are implemented with K-Nearest Neighbor(KNN). Experimental results show that the algorithm achieves higher classification accuracy and stability.
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Computer Engineering. 2011, 37(17): 136-139. https://doi.org/10.3969/j.issn.1000-3428.2011.17.046A new +L-R feature selection algorithm is proposed which combines trace ratio criterion selection and +L-R method based on error region, it uses trace ratio selection to obtain a optimal subset and uses error region by +L-R selection to get a new feature which can classify error sample efficiently in the region of error samples and error classification rate can be decreased efficiently. Using +L-R algorithm can reduce data redundancy. Experimental results show that the proposed algorithm improves trace ratio criterion significantly and lower error rate can be achieved at the same time.
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Computer Engineering. 2011, 37(17): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2011.17.047It is a difficulty to obtain satisfactory solution based on a single structure and mechanism generally. Adding heuristic information of Evolutionary Strategy(ES) and Particle Swarm Optimization(PSO) to artificial fish swarm algorithm, a novel Artificial Fish Swarm Algorithm(AFSA) is proposed. Its convergence is proved. Experimental results show that the algorithm can effectively avoid the basic AFSA into local extremum. It can converge quickly with high adjustment and the effectiveness is also demonstrated by parameter estimation.
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Computer Engineering. 2011, 37(17): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2011.17.048This paper proposes a new entity relation extraction method with a variety of common features plus semantic role features according to the characteristics of entity relation extraction and using the feature vector to build a SVM-classifier. When judging the relation type, this method achieves the F1 measure of 81.6% which is increased by 4% compared with no semantic role features on the data supplied by the evaluation task eight of SemEval-2010. Experimental results show that semantic role feature is benefit to entity relation extraction.
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Computer Engineering. 2011, 37(17): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2011.17.049The paper ameliorates the method that combined K-Nearest Neighbor(KNN) with entropy, a new improved algorithm that adopting entropy as correlation and taking differences values to calculate distance is proposed, which calls FECD-KNN, based on the research that KNN tested sample in misjudgment and error easily. The impacted algorithm combines information entropy theory used to statute correlation, measures strength of impact on the classification according to difference of correlation, and establishes the intrinsic relation between the distance and class. The contrast simulation experiment shows that, compared with KNN and Entropy-KNN, the impacted algorithm adopting the degree of correlation to optimize distance raised the rate of accuracy enormously in classification, meanwhile it also maintains efficiency of classification.
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Computer Engineering. 2011, 37(17): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2011.17.050The current Proportion Integration Differentiation(PID) optimization Design methods are often difficult to consider the system requirements for quickness, reliability and robustness. So this paper proposes an Improved Pareto Genetic Algorithm(IPGA), which uses a new method to calculate crowding distance, improves the comparative method of non-domination, introduces double elitism mechanism to improve efficiency of evolution and quality of solution, and increases diversity of the solution. The algorithm is applied to multi-objective optimization design of PID. Simulation results indicate that a satisfactory solution is selected in Pareto optimum set according to the requirements of the present system.
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Computer Engineering. 2011, 37(17): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2011.17.051The intersection signal control is disposed with the Reinforcement Learning(RL) method based on the neural network function approximate. Considering the stochastic characteristic of the traffic system, an adaptive RL control scheme, based on Cerebellar Model Articulation Controller(CMAC), is introduced in the traffic signal control systems. Besides, CMAC is introduced to approximate the RL agent Q value. The model is tested on a typical isolated traffic intersection comprised of five four-legged signalized intersections, and compared to full-actuated control and pre-timed control. Analysis of simulation results using this approach shows significant improvement over traditional full-actuated control, especially for the case of accident and over-saturated traffic demand.
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Computer Engineering. 2011, 37(17): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2011.17.052A novel algorithm for optimizing the structure and parameters of Direction of Arrival(DOA) estimation model based on radial basis function neural network is presented. By using the astringency of error criteria function, the number of hidden neurons can be decided reasonably, according to the distribution of signal phase difference between the antenna array, the representative hidden neuron centers can be selected. By this way, the constructed RBF model can be represented the direction finding capacity of the antenna array. Compared with the other Radial Basis Function(RBF) methods, the proposed model has the features of more generalization and accuracy DOA estimation. Experimental results show the effectiveness of the proposed approach.
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Computer Engineering. 2011, 37(17): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2011.17.053This paper designs a Simultaneous Localization and Mapping(SLAM) system to realize the mobile robot Simultaneous Localization and Mapping(SLAM) in dynamic environment, and presents the overall framework and realization process. The SLAMiDE system realizes the dynamic map building, static map building and mobile robot localization simultaneously through dynamic objects detection, SLAM and dynamic objects tracking. Experimental results show that SLAMiDE system is testified correct and feasible.
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Computer Engineering. 2011, 37(17): 161-162,166. https://doi.org/10.3969/j.issn.1000-3428.2011.17.054In order to identify the nonlinear system Hammerstein model, the problem of nonlinear system identification is changed into an optimization problem in parameter space. An improved Particle Swarm Optimization based on Normal Cloud(NCPSO) is proposed, in which a dynamic mutation is adopted to make the normal cloud mutation for the best performing particle(Gbest) in the swarm and the best previous position of each particle(Pbest). This mutation will generate the new Pbest and Gbest to lead the whole swarm flight, which effectively avoids the premature convergence. Then a comprehensive learning strategy is introduced to increase the probability of flying to the optimal solution. NCPSO is used to identify Hammerstein model. Experimental results show that the proposed NCPSO has better results than other algorithms.
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Computer Engineering. 2011, 37(17): 163-166. https://doi.org/10.3969/j.issn.1000-3428.2011.17.055Aiming at shortcomings of 2D-Gabor filters and down-sampling of traditional methods, a new method is proposed using statistical sampling of Log-Gabor Features and Support Vector Machine(SVM) for face recognition. A bank of Log-Gabor filters is applied on images to extract features. The statistical sampling and Principal Component Analysis(PCA) are used successively in order to reduce dimensions. SVM is employed for classification. Experimental results based on the ORL and FERET face database show that the novel method achieves high efficiency and strong robustness.
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Computer Engineering. 2011, 37(17): 167-168,171. https://doi.org/10.3969/j.issn.1000-3428.2011.17.056This paper studies strong planning solution under uncertainty. The concept of strong planning solution with minimal cost is proposed and a way for searching strong planning solution with minimal cost is designed, which can figure out the numeric planning problems with the action cost, a weighted algorithm of nondeterministic state-transition system is proposed, which adds the weight to action, that is the action cost, a planning solution with minimal action cost is gotten. Experimental results show that the method for searching strong planning solution with minimal cost is superior to the algorithm based on backward search method for searching strong planning solution.
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Computer Engineering. 2011, 37(17): 169-171. https://doi.org/10.3969/j.issn.1000-3428.2011.17.057Aiming at the problem that traditional Scale Invariant Feature Transform(SIFT) algorithm may cause error match in low resolution palmprint image, this paper proposes a novel approach of palmprint recognition based on improved SIFT algorithm. According to the thought of local match, the algorithm combines the Euclidean distance and weighted sub-region. The similarity calculated can reflect the local and global features of images. Simulation results prove that the recognition rate of the improved SIFT algorithm is higher than the recognition rate of SIFT algorithm.
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Computer Engineering. 2011, 37(17): 172-174,177. https://doi.org/10.3969/j.issn.1000-3428.2011.17.058This paper focuses on the modeling for supplier selection of medical resources, develops a multicriteria ranking method for supplier in which the information on the criteria’s weights is incomplete and the criteria’s value is interval intuitionistic fuzzy set. The interval-valued intuitionistic fuzzy set of each supplier is aggregated through logical algorithms and the Hamming distance of each supplier is obtained. By using particle swarm optimization algorithms to solve the nonlinear programming models and the optional criteria weights are gained, and ranking is performed through the comparison of the distances between each supplier and superior/inferior supplier alternative. Eventually, a supplier selection example under mass emergency is provided to demonstrate the validity and feasibility of the model and algorithm.
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Computer Engineering. 2011, 37(17): 175-177. https://doi.org/10.3969/j.issn.1000-3428.2011.17.059To deal with the new time and space challenges of the machine learning problem algorithms from large scale data, this paper focuses on sparse-learning and categorizes the L1 regularized problem’s the-state-of-the-art solvers from the view of multi-stage and multi-step optimization schemes. It compares the algorithms’ convergence properties, time and space cost and the sparsity of these solvers. The analysis shows that those algorithms sufficiently exploiting the machine learning problem’s specific structure obtain better sparsity as well as faster convergence rate.
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Computer Engineering. 2011, 37(17): 178-180,184. https://doi.org/10.3969/j.issn.1000-3428.2011.17.060As the diversity of the data collection, it is necessary to enhance the flexibility of the algorithm when reduce the dimensions of the data sets. The article changes the constraints of the Local Preserving Projection(LPP) algorithm by adding an exponential parameter p. Then can see the result of dimension reduction and look over the recognition rate through different face databases. The article also attempts to summarize the scope of p and design experience. Experimental show that the exponential parameter does influent the dimension reduction results. The dimension can be lower and if select the proper p the result will be better. If add gussian white noise, the consequent is still better by adjusting the exponential parameter p.
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Computer Engineering. 2011, 37(17): 181-184. https://doi.org/10.3969/j.issn.1000-3428.2011.17.061To improve the efficiency of Bayesian Network(BN) structure learning, this paper developes a novel algorithm based on chain-model and particle swarm. It measures the quality of topological orders with a regular chain-model which contains information of causality between nodes, so that the quality of the searched topological orders is improved. And then the position-selectable updating PSO is optimized with dynamical weighting coefficient, which balances global search and local search and improves search capability. Experimental results show that the novel algorithm can get a better solution, and convergence rate is enhanced with a comparison to the I-ACO-B algorithm.
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Computer Engineering. 2011, 37(17): 185-187,196. https://doi.org/10.3969/j.issn.1000-3428.2011.17.062Aiming at the problem that most of data association algorithm can’t amend past error associations on line, this paper presents a heuristic graph search algorithm which uses dynamic threshold. The algorithm uses recall to reach amend past error associations and uses dynamic threshold to reduce the number of probable data association. The algorithm doesn’t lower the accuracy of data association but raise the efficiency of data association. Experimental result shows that the algorithm takes less times.
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Computer Engineering. 2011, 37(17): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2011.17.063Data allocation in layered P2P streaming media is proved to be a NP-complete problem. The existing algorithm is a heuristic algorithm based on the greedy idea, which can not get the global solution. In order to develop a new algorithm for this problem, it defines the concept of data blocks for choosing, sets up a mathematic model of integer programming without restriction, and proposes a novel Particle Swarm Genetic Algorithm(PSGA) based on the encoding manner of Data Blocks for Choosing. Simulation demonstrates that the proposed PSGA’s performance improves 5%~25% than that of the existing algorithm.
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Computer Engineering. 2011, 37(17): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2011.17.064In order to improve the image edge detection accuracy and noise performance, this paper proposes an image edge detection algorithm based on ant colony optimization. The value of pixel gradient and the relative difference of statistical means of the pixel’s circle neighborhood are combined to be the heuristic information which can guide ant’s searching. Experimental results show that the edge detected by the proposed algorithm is robust to noise and texture, and contains most of the edge details.
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Computer Engineering. 2011, 37(17): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2011.17.065In order to test the retrieval performance of the Bessel-Fourier Moment(BFM), the feature descriptor extracted with the proposed algorithm is used for image retrieval and classification in different databases: ICU and ILL databases. Experimental results show that the higher retrieval precision rate can be achieved, and the curve of RPP amounts to an ideal state for invariant texture retrieval. The performance of BFM is better for shape recognition, and has strong robustness to varying illumination and rotational invariance in color images retrieval. The BFM achieves higher correct classification rate than conventional descriptors with the same order.
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Computer Engineering. 2011, 37(17): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2011.17.066Synthetic Aperture Radar(SAR) and Panchromatic Remote Sensing(PRS) images have different performance on the surface features of the target owing to their imaging mechanism, such as contour, texture. The pixel-level fused image is more favorable for interpretation. Based on this consideration, the Shift Invariance Discrete Wavelet Transform(SIDWT) algorithm is used for fusing SAR and PRS images, which overcomes the weakness of the shift variant of the traditional wavelet. A new fusion rules is presented for complementarity information enhancement, the fused approximate coefficients are obtained by weight rule based on edge extracting, maximum absolution value rule is used to fuse the detailed coefficients. Experimental results for real images demonstrate the effectiveness of the proposed algorithm.
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Computer Engineering. 2011, 37(17): 200-202,205. https://doi.org/10.3969/j.issn.1000-3428.2011.17.067Aiming at the complication of modulating different parameters of nonlinear gain function on general image enhancement algorithm based on curvelet transform, an improved algorithm of image nonlinear enhancement based on curvelet transform is given in this paper. It analyzes and processes the spatial feature before low contrast image is processed, then combines the spatial nonlinear transform and curvelet nonlinear transform, through the choice of less parameters and combination of multiscale characteristic of curvelet transform to improve the self-adaption of curvelet enhancement. Experimental results demonstrate that the proposed method has better effect on image enhancement.
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Computer Engineering. 2011, 37(17): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2011.17.068The Chan-Vese(C-V) model based on global region information is less sensitive to initialization and noise, but it cannot handle images with intensity inhomogeneity. RSF model based on local region information is able to deal with intensity inhomogeneity, but it is highly sensitive to initialization and noise. In order to address this problem, this paper proposes a novel level set regularization term, and then proposes a new active contour model with a partial differential equation, which integrates both global and local region information. Experimental results show that the proposed model can segment images with intensity inhomogeneity, while it allows for flexible initialization and is less sensitive to noise.
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Computer Engineering. 2011, 37(17): 206-207,210. https://doi.org/10.3969/j.issn.1000-3428.2011.17.069The traditional histogram equalization method can not enhance the local details of the image. Aiming at this problem, this paper proposes an adaptive multi-thresholds histogram equalization method on the basis of multilevel component-based histogram equalization method. It makes an adaptive selection of channels and thresholds based on the analysis of input image. Experimental results demonstrates that the proposed method not only enhances both global and local details better, but also reduces the processing time and noise.
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Computer Engineering. 2011, 37(17): 208-210. https://doi.org/10.3969/j.issn.1000-3428.2011.17.070Mathematical morphology amoebas method can segment the fingerprint, but the run speed is slow for the large computation. Aiming at this problem, this paper proposes a fast segmentation method of fingerprint image based on the mathematical morphology amoebas and Discrete Wavelet Transform(DWT). It uses the wavelet decomposition, and segments the low frequency image using morphology amoebas. Experimental results show that this method ensures good segmentation accuracy and realizes the fast segmentation of fingerprint image.
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Computer Engineering. 2011, 37(17): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2011.17.071It proposes an automatic white balance method based on Raw format image. The method makes an assay of color statistics characteristics for Raw data which getting from image sensor. On this basis, it achieves an adaptive algorithm of white balance, and the method not only makes full use of the imaging analysis capabilities of image sensor, but also reduces the computational complexity. Experimental results show that, on a large number of natural images set, the method has better color balance effect and better computational efficiency.
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Computer Engineering. 2011, 37(17): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2011.17.072Aiming at the features of Electric Multiple Unit(EMU) maintenance are high cost, low accuracy and efficiency, the virtual maintenance and simulation system of EMU is designed and realized. The reconstruction of assembly tree, the rendering optimization of large and complicated model and the simulation for process are proposed based on the 3D OpenSceneGraph engine. The practice results show that the developed system can satisfy the need for the tasks of EMU maintenance training, the money is saved and the training efficiency is improved.
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Computer Engineering. 2011, 37(17): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2011.17.073Considering the facts that the terrain under the coal mine personnel orientation is difficult to locate, and the existing algorithm is highly positioning error, this paper designs an improved maximal-cluster centered positioning algorithm based on range-free technology. By using the output of Receive Strength Signal Indicator(RSSI), this algorithm classifies the position of moving nodes in the locating area. By means of the improved cluster generating condition and classification logic, this algorithm solves the locating blind spots problems which are not solved efficiently in the existing literatures. Results of numerical simulation and experimentation indicate that this algorithm is of high accuracy of location and it is adapt to complex communication condition under coal mine.
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Computer Engineering. 2011, 37(17): 220-222,226. https://doi.org/10.3969/j.issn.1000-3428.2011.17.074While measuring radio frequency plasma’s parameters by Langmuir probe, the I-V characteristic curve is always distorted by electromagnetic interference, and this influences the parameters calculation and analysis. This paper adopts a Savitzky-Golay(SG) filtering algorithm which is used for smoothing I-V characteristic curve, and this brings accurate parameters. Experimental results show Savitzky-Golay filtering of the divided I-V characteristic can bring low signal distortion rate and high accurate Electron Energy Probability Function(EEPF).
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Computer Engineering. 2011, 37(17): 223-226. https://doi.org/10.3969/j.issn.1000-3428.2011.17.075Aiming at the complex nature of the nonlinear existing in mine hoist fault time series, this paper uses the phase space reconstruction method to reconstruct the multi-dimension phase space for mine hoister fault time series. Based on chaos theory, the correlation dimension and the largest Lyapunov exponents are applied to analyze the features of mine hoist fault time series to realize the fault diagnosis for hoister. Research results show that mine hoist fault time series possesses chaotic characteristics, and the calculated correlation dimension and the largest Lyapunov exponents can be used for the characteristics in mine hoist fault diagnosis.
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Computer Engineering. 2011, 37(17): 227-229,232. https://doi.org/10.3969/j.issn.1000-3428.2011.17.076According to the standard specification, planetary data characteristics of Planetary Data System(PDS) and PDS metadata model, this paper designs a planetary data cataloging model. By extending traditional data cataloging model to support data show and space inquires, using the method of object-relational database to store cataloging information to realize data management, filing and distribution. The planetary data cataloging index system validates the correctness and effectiveness of the model, and shows that this model can provide a consistent directory access interface, makes the user quickly and easily to retrieve the interested planet data.
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Computer Engineering. 2011, 37(17): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2011.17.077A new kind of Costas loop is designed with logistic modules instead of the primary Direct Digital Synthesizer(DDS) module in order to save logical resource in multi-carriers extraction and Direct Digital Control(DDC). The result of design shows that the proposed way is satisfactory for practical application and logical resource is saved by 25%. This new proposal is valuable to extraction of multi-carriers, especially in radar array signal processing.
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Computer Engineering. 2011, 37(17): 233-235,238. https://doi.org/10.3969/j.issn.1000-3428.2011.17.078A new model to design data classifiers by using orthogonal state basis with time is presented. The space of input data is extended to a relevant complete orthogonal feature subspace according to the unique characteristics of the input variables, results in the formation of categorical orthogonal state basis and the classification matrix. The unknown input data is projected onto the subspace through the matrix to be sorted, the time variable is introduced as an exponential factor and the duration of a state lasted is calculated, and the second classification based on the time duration of a state is performed. It applies experimentally such model to a boat sewage purifier for the classification of its 13 working states, and the results indicate that the fault modes can be effectively discerned and the behaviors of the machine system can be monitored and properly treated.
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Computer Engineering. 2011, 37(17): 236-238. https://doi.org/10.3969/j.issn.1000-3428.2011.17.079Aiming at the limitations of real-time interrupt applications of Linux2.6, this paper proposes a real-time improved scheme based on CK-CPU. It implements Fast Interrupt Request(FIQ) to respond real-time interrupts specially, adding a scheduling policy of real-time process after FIQ routine, and caches the FIQ common code and stack in Scratch Pad Memory(SPM), reducing memory access of FIQ routine and running faster. Experimental results show this scheme can improve real-time performance of Linux2.6 apparently.
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Computer Engineering. 2011, 37(17): 239-241. https://doi.org/10.3969/j.issn.1000-3428.2011.17.080In this paper, an off-line processing and visualization system of 3D phased array sonar data is designed. The system consists of modules of sonar data parsing, single-frame reconstruction, accurate registration, mosaicing and multi-frame reconstruction. The accurate registration module which includes Iterated Closest Point(ICP) algorithm with robust outlier rejection and Quasi-newton optimization, improves the precision of registration. The mosaicing and multi-frame reconstruction module reconstruct a range of frames by multilevel resolutions, which supports rapid display at low resolutions and also precise display for details at high resolutions. Test results show that this system can successfully complete the processing and visualization of phased array sonar data.
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Computer Engineering. 2011, 37(17): 242-244. https://doi.org/10.3969/j.issn.1000-3428.2011.17.081For μC/OS-Ⅱ doesn’t support bottom half interrupt, this paper presents an implementation scheme of bottom half mechanism for μC/OS-Ⅱ. According to the priorities of interrupts, it can be triggered statically by some special interrupts with priorities, and it also supports dynamic registration for interrupts without priorities. This mechanism improves the system performance. This mechanism has already been achieved, and used in ocean data buoy system successfully. Result shows that it can improve the system response speed and stability.
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Computer Engineering. 2011, 37(17): 245-247. https://doi.org/10.3969/j.issn.1000-3428.2011.17.082This paper researches distributed video coding performance based on n-nary Low Density Parity Check(LDPC) code. According to the characteristics of the n-nary sources, Laplacian distribution is used to improve the correlation model of the n-nary sources. FFT-BP algorithm of n-nary LDPC code is modified to be applicable to the system. Simulation results show that, with the same value of Peak Signal to Noise Ratio (PSNR), the average code rate of distributed video coding using 4-ary LDPC codes is reduced by 0.028 3 bit/pixel compared to the distributed video coding using binary LDPC codes and the average code rate of distributed video coding using 8-ary LDPC codes is reduced by 0.037 0 bit/pixel. And compared with other distributed source coding systems, the decoding speed is higher and the complexity is lower.
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Computer Engineering. 2011, 37(17): 248-249. https://doi.org/10.3969/j.issn.1000-3428.2011.17.083Considering the efficiency problem of the BM pattern matching algorithm, this paper proposes an improved BM pattern matching algorithm. Analyzing the character of it, if some continuous characters are not appearing in the model string, then the characters needn’t to be compared, so this method changes the model string comparing order, and the matching efficiency of BM algorithm is enhanced. Experimental results show that the improved BM pattern matching algorithm can effectively decrease the times of string matching and comparing, and get the good string matching efficiency.
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Computer Engineering. 2011, 37(17): 250-251,255. https://doi.org/10.3969/j.issn.1000-3428.2011.17.084Multi-mode prediction can improve compression efficiency and rate-distortion performance of H.264, but it also increases the coding complexity. This paper proposes a mode selection algorithm according to the complexity of the variable block-size in motion prediction. The all-zero block distribution in the macroblock, Sum of Absolute Difference(SAD) of the blocks in macroblock and volume of motion vector for macroblock are utilized as decision criterions to lessen candidate mode set and to enhance the coding speed. Simulation result demonstrates that the algorithm can get 37%~93% enhancement of encoding speed versus full search algorithm while incurring imperceptible image quality.
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Computer Engineering. 2011, 37(17): 252-255. https://doi.org/10.3969/j.issn.1000-3428.2011.17.085Aiming at the partial invalidity problem which exists in fuzzy comprehensive evaluations, this paper proposes a new relative membership grade weighted mean method. According to the characteristics and requirements of civil-air-defense plan, this algorithm selects the hierarchical indicator system, determines factors weight binding the information entropy, uses relative membership grade weighted mean as evaluation function. Evaluation model is established to evaluate the civil-air-defense plan, it provides important basis for readjusting action project dynamically.
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Computer Engineering. 2011, 37(17): 256-258,261. https://doi.org/10.3969/j.issn.1000-3428.2011.17.086This paper proposes a lineage tracing frame for Extraction-Transform-Load(ETL) process, and discusses some key issues in this system, such as classifying the transformations, the designing of metadata, constructing transformation series, tracing process design and the tracing methods for every type of the transformation. The metadata for tracing is injected into the package file, these information are extracted when tracing query were proposed to support data tracing.
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Computer Engineering. 2011, 37(17): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2011.17.087In order to reduce complexity of AVS inter-frame mode selection algorithm, this paper proposes a self-adaptive threshold algorithm for inter mode fast selection. The most likely prediction mode of current macro-block is predicted by using the prediction mode correlation of adjacent macro-block and the statistical distribution of prediction modes. The adaptive threshold is set by using the rate-distortion cost correlation of the adjacent macro-block. If the rate-distortion cost of the most likely prediction mode meets the threshold criterion, the mode search exits. Experimental results show that the algorithm get higher encoding speed while maintaining AVS encoding performance.
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Computer Engineering. 2011, 37(17): 262-264,267. https://doi.org/10.3969/j.issn.1000-3428.2011.17.088According to the characteristic of continuous consume resources schedule emergency problem, the expression of the earliest emergency start-time is proposed based on the existing results and its proof is given in this paper. The multi-objectives nonlinear integer model is established for the one-emergency spot system. The reliability of the optimal decision is considered in this model. Further, the model is extended in condition of the multi-emergency spots, and its algorithm is given. The resources dispatch scheme is obtained based on the earliest emergency-start-time to minimize the number of retrieval sports and supply route. It gives examples to illustrate the rationality of the model and the efficiency of the algorithm proposed in this paper.
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Computer Engineering. 2011, 37(17): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2011.17.089This paper proposes a key frame extraction algorithm based on Rough Set(RS) in compressed domain. It extracts I frame from compressed domain data sequence, and constructs information system with the difference between two adjacent I frames in column and attributes sets which are extracted from decompressed I frames in row, then the established information system is normalized and discredited. It simplifies information system by using attribute reduce theory of RS to obtain attribute cores without redundancy, and key frame is extracted by using the indiscernibility relation of RS. Experimental result shows that, competed with pixel difference algorithm and direct current coefficient algorithm, the algorithm proposed can reduce the complexity of computing and can be used for different types of video effectively.
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Computer Engineering. 2011, 37(17): 268-270,273. https://doi.org/10.3969/j.issn.1000-3428.2011.17.090Aiming at electricity system dynamic electromagnetism transient state parallel computing pass real-time and hard real-time problem, this paper proposes a real-time parallel computing platform which is based on MPI. By introducing hard real-time operating system, RTLinux, and using real-time core, PSDD programming model to reconstruct the simulation parallel computing program, MPICH parallel circumstance and GM software, it can have hard real-time character. Test results show that, the average time performance enhances about 10%, and maximum jitter range reduces 50%~80%. It can also reduce time jitter frequency.
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Computer Engineering. 2011, 37(17): 271-273. https://doi.org/10.3969/j.issn.1000-3428.2011.17.091In order to establish stereo vision on the flat screen, by simulating human eyes’ process of acquiring images in the real-world, this paper introduces methods of rendering binocular parallax images by the computer. Two models of view frustum placement in the virtual environment are given. Through projective analyzing result can be concluded that toe-in model causes vertical parallax and variance of horizontal parallax which leads to deformation of depth perception in the same depth of virtual environment. Off-axis model conforms to the human eye habit of establishing stereo vision and correctly reflects the depth of the object before and after physical screen. Binocular images created by off-axis model have lager field of view.
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Computer Engineering. 2011, 37(17): 274-275,278. https://doi.org/10.3969/j.issn.1000-3428.2011.17.092When single forecasting model forecastes the crime quantity, it is difficult to coordinate the fitting and generalization. The result of forecasting is not accuracy. Aiming at the problem presented above, this paper proposes a data-driven dynamic optimization combination forecasting method based on each advantages of the model virtues of Autoregressive Integrated Moving Average(ARIMA), Vector Autoregressive Model(VAR) and Support Vector Machine(SVM). The method gives the weight to each model by using the posterior probability, then dynamic adjusts the weight on the principle of minimum error. Experimental results show that the method has high prediction accuracy and stability to meet the needs of short-time crime forecasting.
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Computer Engineering. 2011, 37(17): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2011.17.093In order to enhance the resources utilization and services availability of virtual machines migration, a virtual machine migration schedule strategy based on load characteristic is proposed. Aiming at the trigger types of nodes and the load characteristics of virtual machines, using multi-threshold mode to trigger the migration, the virtual machine to be migrated is selected and the destination node is positioned. Experimental results show that, the strategy can realise the self-managed of virtual machine migration. The utilization efficiency of resources can be significantly enhanced. The strategy has good adaptivity.
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Computer Engineering. 2011, 37(17): 279-281,285. https://doi.org/10.3969/j.issn.1000-3428.2011.17.094Analysing the time complexity and space complexity of Dijkstra Algorithm, restricted area search algorithm and A* algorithm, on the bases this, the paper proposes a shortest route search algorithm. The algorithm makes the static memory and dynamic search combined, uses the restricted area research algorithm as the main algorithm, is supplemented by A* algorithm, according to the port road condition to realize the algorithm. Experimental results show that the algorithm can enhance the route searching efficiency in the occasion of regular road network structure.
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Computer Engineering. 2011, 37(17): 282-285. https://doi.org/10.3969/j.issn.1000-3428.2011.17.095Due to the problem of inefficient junk fax prevention, this paper proposes an improved prevention scheme based on the design methods of existing safety fax server. The basic principle is that screen automatic fax by adding Turing test function before receiving faxes. Through approximate string matching technology, junk faxes are detected, and then filtrated by blacklist function. Furthermore, the proposed system regards clustering function as an assistant method to discover new junk fax and rich keywords library. Experimental results show compared with the original design, this method has higher accuracy, faster detection speed, less manual intervention and stronger usability.
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Computer Engineering. 2011, 37(17): 286-287,290. https://doi.org/10.3969/j.issn.1000-3428.2011.17.096Interpolation-based fusion method using 2D mean-value coordinates may product some unnatural effects. Aiming at this problem, this paper presents a new method of video fusion to avoid these flaws. Based on 3D mean-value coordinates, a boundary-aware algorithm is provided to optimize the determination of 3D mean-value coordinates. Matting-based methods are used to refine produced video. Experimental results show that this method can enhance the quality of composition more effectively compared with the existing approaches.
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Computer Engineering. 2011, 37(17): 288-290. https://doi.org/10.3969/j.issn.1000-3428.2011.17.097With the methods of Colored Petri Net(CPN) and CPN Tools platform, this paper establishes a top-down hierarchical model of adaptive OFDMA system and uses the Monitor to monitor its performance analysis. With this model, the description of the process for the system is easier to understand intuitively and on-limits, which can be applied to different algorithms. It is applies to the business that the user arrival interval and processing time are not exponentially distributed. The simulation result is compared with M|M|m|n queuing model in order to verify the validity of the model.
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Computer Engineering. 2011, 37(17): 291-292,封三. https://doi.org/10.3969/j.issn.1000-3428.2011.17.098Aiming at the problem of analog circuit fault diagnosis, a novel approach based on random subspace method and Support Vector Machine(SVM) is presented. Simulation results of diagnosing the international benchmark circuits-leapfrog filter, compared with several existent fault diagnosis methods such as BPNN, GENN, O-V-O SVM, show that the proposed method has the highest classification accuracy.
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