20 June 2011, Volume 37 Issue 12
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Computer Engineering. 2011, 37(12): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2011.12.001Existed photo management systems fails to organize the semantic annotations of photo effectively, the information can not be reused. In order to overcome these shortcomings, an ontology-based approach is proposed for the digital photo management. The FamilyAlbum ontology is built to provide knowledge framework for the whole system. Based on the ontology, it also proposes an automatic annotation method extracting semantic conceptions from the multi-source information. The SWRL rules are written and executed to inference new semantic concepts for the ontology model. The inferences also extends the semantic annotations of photos in the system. It makes intelligent retrieval possible in the photo management system. The FamilyAlbum ontology is implemented in the OntoAlbum prototype system. Experiments on the OntoAlbum system show the approach is effective.
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Computer Engineering. 2011, 37(12): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2011.12.002This paper presents an integrated simulation framework to evaluate evacuation efficiency for building plans from Computer Aided Design(CAD) drawings. Geographic Information System(GIS) based real time analysis is carried out to capture spatial information among scenario variables and thereby simulate human perceptions and interactions. Building layout and human behaviors are represented in virtual evacuation scenarios using Virtual Reality(VR) technology. The views are integrated into the framework based on Client-Server mechanism. The case study demonstrates that integrated simulation with CAD, GIS and VR views can facilitate the visualization of evacuation simulation
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Computer Engineering. 2011, 37(12): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2011.12.003This paper proposes a synthetic assessment method based on the decision rules from Variable Consistency Dominance-based Rough Set Approach(VC-DRSA). By applying the principle of prudence and the principle of maximum net present value, it combines quantitative analysis with qualitative analysis effectively. Besides, this method is a two-stage procedure, first training and then decision, which is under no restraint of some specific assessment models and especially suitable for large scale decision making problems. Simulation results show that this method can classify the data scientifically and improve the data mining efficiency of the information system.
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Computer Engineering. 2011, 37(12): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2011.12.004It is difficult to satisfy the practical demand for scheduling time-triggered tasks and event-triggered tasks in embedded real-time system with cooperative or preemptive schedule separately. In order to combine the advantages of different schedule methods and triggering methods, and improve schedule performance, this paper designs a real-time operating system named SinewOS based on hybrid architecture. It supports scheduling multi-task including cooperative tasks and preemptive tasks in hybrid mode. Experimental result proves that the system gains good predictability and determinism, fast responsiveness and low system overhead, and it can be used in many electronic fields.
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Computer Engineering. 2011, 37(12): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2011.12.005In palmprint recognition, in order to learn the higher order dependencies associated with the different factors quickly and effectively, this paper uses Multilinear Independent Component Analysis(MICA) to the original tensor objects to obtain the low-dimension mode matrix. The palmprint images are projected onto the mode matrix for extracting the core tensors. Palmprint matching is implemented by calculating the cosine distance between two core tensors. Experiment based on PolyU plmprint database shows that compared with Principal Component Analysis(PCA), 2DPCA, Independent Component Analysis(ICA) and Multilinear Principal Component Analysis(MPCA), recognition rate of the new algorithm is the highest, and it meets real-time requirements of the system.
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Computer Engineering. 2011, 37(12): 16-18. https://doi.org/10.3969/j.issn.1000-3428.2011.12.006This paper studies the job schedule problem in commercial grid computing. Four parameters of jobs, arrival time, computation, budget and deadline, are used to define a priority of jobs. A job schedule algorithm is proposed and simulated. Results of simulation show that this algorithm outperforms existing algorithms in metrics of Hit Value Ratio(HVR), Weighted Job Fulfillment Ratio(WJFR), and number of jobs finished before deadline. It achieves higher quality of service for consumers and higher income for providers than the contrastive algorithms.
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Computer Engineering. 2011, 37(12): 19-22. https://doi.org/10.3969/j.issn.1000-3428.2011.12.007
This paper analyzes the characteristics of the Publish/Subscribe(Pub/Sub) system, proposes a novel Constrained number of Message Copy Pub/Sub Scheme(CMCPSS) algorithm for opportunistic networks, which can calculate the copy number of subscribe request and the response event according to the communication frequency between different nodes adaptively. Simulation results show that CMCPSS can balance well the tradeoff between the delivery ratio and network resource consumption in intermittently connected networks. CMCPSS can reduce 51% transmission times when compares with Epidemic algorithm and can reduce 45% message transmission delay when compares with Direct Transmission algorithm.
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Computer Engineering. 2011, 37(12): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2011.12.008
Aiming at the problem that it will cause extra costs when introducing control flow obfuscation, this paper puts forward to make use of the garbage code to carry out the control flow confusion. The branch garbage code and circulation the garbage code are used in the method and a Hash function is introduced here to control the number of insert operation, so the accuracy of the program analysis is decreased greatly and the tamper attack is hard to attain its purpose.It implements part of the algorithm and analyze its efficiency. Experimental results show that the algorithm can effectively prevent reverse engineering attacks.
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Computer Engineering. 2011, 37(12): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2011.12.009
Aiming at solving problems of relatively low precision, rate of coverage when using existing attribute word extraction methods, this paper adopts Baidu Baike and co-occurrence proportion of adjacent words after word segmentation to identify new domain words, decreases impact on recognition of attribute word caused by segmentation errors. This paper designs part of speech sequence templates which contain noun and noun phrase templates, verb and verb phrase templates to obtain attribute word candidates from Chinese product comments, then utilizes statistical technique and natural language processing technique to filter attribute word candidates. Experimental results show that for the 3 623 mobile phone comments, this method obtains 1 732 attribute words, the precision, recall and f-measure reach 0.565, 0.726 and 0.636, and it has good extraction performance.
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Computer Engineering. 2011, 37(12): 29-32. https://doi.org/10.3969/j.issn.1000-3428.2011.12.010According to low efficiency in network database accessing in unreliable military communication system, this paper proposes the database access model based on distributed component. The clients reduces accessing database times through caching data, and the database server administrates the connection with clients using distributed component, then notifies clients updating data, which can reduce the data traffic in the network. Estimational result proves that the efficiency in the application system can be improved.
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Computer Engineering. 2011, 37(12): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2011.12.011Recovery from malicious transaction has become an important method to protect database, the new recovery mechanism raises new requirement that the log file should not only record information of write operation but also the information of read operation. To fulfill the new requirement, a new log strategy is proposed, According to this strategy, the log system is designed and implemented, the system is composed by four parts: SQL statements filtrating, sensitive information setting, write log generator and read log generator. Structured Query Language(SQL) statements filtrating aims to protect the log file from malicious users. Sensitive information setting gives constraints to log record to control the size of log file. Write log generator uses triggers to records the information of write operation. Read log generator records the information of read operation via re-constructing SQL statements, creating temporary table and accessing temporary table. Experimental result shows that log system records database operations effectively, but decreases the efficiency of the whole system.
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Computer Engineering. 2011, 37(12): 36-37. https://doi.org/10.3969/j.issn.1000-3428.2011.12.012In order to design effective software defect prediction model, this paper proposes an approach combining Particle Swarm Optimization(PSO) algorithm and Na?ve Bayes(NB). After discretizing the original data, the error rate of NB is taken as fitness function of the particle, and a software defect prediction model is constructed. It applies one software project JM1 data of NASA to implement the simulation experiment. The results show that the approach proposed has lower error rate than other methods, and has good performance.
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Computer Engineering. 2011, 37(12): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2011.12.013It is a difficulty problem that how to improve the recall and the accuracy ratio simultaneously on information searching. In view of this question, this paper proposes one kind of improved sentence similarity algorithm which based on the semantic interdependence degree. IT analyses the characteristics of algorithm based on semantic interdependence similarity, adds the semantic role labeling information through determining weights of the sentences effective collocation, and then weights the algorithm of keyword similarity calculation, then proves this algorithm feasibility with the example, makes re-sorting with the improved algorithm for inquiry results, which founded on enhancing the inquiry system recall. Thus enhance the accuracy ratio of the first K returns results. Experiment proves that this algorithm improves accuracy ratio of system, the first 20 of re-sorting compared with the before of system sorting, to enhance 3.6%.
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Computer Engineering. 2011, 37(12): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2011.12.014By introducing formal Quality of Service(QoS) description, service provider factor, service consumer factor in Web services dynamic composition, a method of QoS computing based on Analytic Hierarchy Process(AHP) is proposed. It selects QoS factors according to service consumer expectations, computes the quality of Web service with QoS weight, and proposes a QoS-based Web services dynamic composition model. An example is provided to prove that higher quality value-added services can be obtained with the computing method proposed.
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Computer Engineering. 2011, 37(12): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2011.12.015Taking Business Process Execution Language(BPEL) as the physical model, through the mapping between repository in ArtiFlow and service in BPEL or service in ArtiFlow and service in BPEL, this paper selects the services used in the logic model. By using the related element information in ArtiFlow, it constructs the invoked relationship of services in the physical model. So it realizes automatic translation from AtifFow to physical model. Experimental result proves the availability of the translation approach.
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Computer Engineering. 2011, 37(12): 47-50. https://doi.org/10.3969/j.issn.1000-3428.2011.12.016This paper introduces the Boolean matrix into the both positive and negative association rules, based on the Duel Correlated Mining (DCM) algorithm, it presents a Deep Web complex schema matching algorithm. It transforms the attributes in the query interface schemas into a Boolean matrix, mines group attributes by positively calculating for matrix and mines synonymous attributes by negatively calculating for matrix. Experimental results show that the algorithm has higher efficiency.
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Computer Engineering. 2011, 37(12): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2011.12.017Most clustering algorithms can not meet the demand of speed and self-adapting about text clustering. In this paper, after fundamental theory and implement are expounded, the idea of creating an algorithm based improved DBSCAN is proposed. The least square method is used for decreasing divisions and the cluster-tree is created to gain a strong self-adapting of the algorithm. According to the data from an experiment mentioned in this paper, the self-adapting algorithm is feasible and involves better performance than DBSCAN.
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Computer Engineering. 2011, 37(12): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2011.12.018In order to discribe the geographical relevance among tourist attractions based on road information, this paper proposes several concepts including road network model, constrained road distance and neighbor road in radius of R. Constrained Spatial Autocorrelation(CSA) and Shortest Road Path(SRP) algorithm are presented to search the shortest road and computer length of the load. Experiments are conducted with the trunk road data from Guizhou province in the form of MapInfo format, and the results show that SRP can find the shortest road path efficiently and quickly.
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Computer Engineering. 2011, 37(12): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2011.12.019
This paper presents a grid growing algorithm for fast construction of Delaunay irregular network based on discrete point. In this algorithm, a grid is achieved to express discrete point uniquely based on the divide-and-conquer method, which is compressed storage in a sparse matrix, and an efficient retrieval method is established between value cell and discrete point by identification code, which is effectively to improve the efficiency of the construction of Triangular Irregular Network(TIN). According to the density of value cells, a default square search space is acquired, and it is allowed to create the square search space dynamically in the expansion process of TIN, which ensures the accuracy of the grid growing. Experimental results show that the time complexity of the proposed algorithm is O(nlogn), and the algorithm is available to both small and massive amount of discrete points.
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Computer Engineering. 2011, 37(12): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2011.12.020This paper proposes a method for software security design based on security pattern. A new security stereotype is introduced, which can be used to denote security concerns and establish high level abstraction of system security. The process of security design with the usage of security stereotype and security patterns is described, and it gives a system design class diagram of application example. The way to design and implement security pattern library is given and it compares the method with other software design methods.
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Computer Engineering. 2011, 37(12): 62-63. https://doi.org/10.3969/j.issn.1000-3428.2011.12.021Based on Low-Energy Adaptive Clustering Hierarchy(LEACH) algorithm, a new algorithm for Wireless Sensor Network(WSN) based on Fuzzy C-Means(FCM) is proposed. In the cluster formation stage, the nodes in the wireless sensor network are divided into Q clusters. Each node belongs to one of the cluster. In the entire network life cycle, this cluster will be fixed. In the new round begin, the choose of cluster head node is based on the current energy value in a cluster. During the data transmission, the communication takes the single-hop in a cluster and multi-hop in inter-cluster. Simulation results show that the algorithm is rational and efficient.
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Computer Engineering. 2011, 37(12): 64-67. https://doi.org/10.3969/j.issn.1000-3428.2011.12.022Aiming at the problem that terminal anchor information can not consistent with reality, and signal sends abnormally when terminal access accordance with the standard of WiMAX network architecture, this paper designs and implements the MS state module, to manage some information when users access, maintain the terminals status and position information, provide and preserve the authentication and authorization strategies. Result proves that the WiMAX access gateway achieves a more orderly, accurately and rapidly terminal access.
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Computer Engineering. 2011, 37(12): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2011.12.023
According to the widespread use and various Quality of Service(QoS) for VANET application, an end-to-end communication software bus with callback function, registered API and communication mechanism of virtual shared memory is proposed under the guidance of design method. This software bus supports TCP, UDP AUDP(Acknowledged User Datagram Protocol) and various transport protocols extension, and is convenient for loosely coupled system integration and transparent information transmission. Simulation result indicates that the software bus is able to satisfy diverse QoS, including average delay of end to end, average jitter and packet delivery radio by setting up priority.
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Computer Engineering. 2011, 37(12): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2011.12.024Grounded on the analysis of the latest bidding algorithm, contra posing to low utilization of spectrum in spectrum allocation, a bidding mechanism-based spectrum allocation algorithm of high spectrum utilization is proposed in Cognitive Radio(CR). And the interference pricing is introduced which makes the system interference reduced by setting the interference pricing index, then the quality of service of primary user is ensured. Simulation results demonstrate that the proposed algorithm is effective to improve the spectrum utilization and increase system throughput by multiple allocation.
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Computer Engineering. 2011, 37(12): 74-75. https://doi.org/10.3969/j.issn.1000-3428.2011.12.025
A Call Admission Control(CAC) scheme based on load balance is proposed to avoid the congestion due to the asymmetry of service resource requirements. Traffic is classified in this scheme. According to system’s different uplink load and downlink load situation, different method is adopted to reduce load imbalance distance of system. The aim to load balance is achieved. Numerical results demonstrate that the scheme can reduce blocking rate well and improve performance of system efficiently.
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Computer Engineering. 2011, 37(12): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2011.12.026According to the problem of the 3rd Generation mobile systems(3G) streaming media network delay, this paper puts forward a streaming media schedule strategy, which uses Least Recently Used(LRU) algorithm to manage the internal memory and adopts the strategy that first come first served for small files and the time slice circular for large files to send the files reasonably. It is proved by practice that the method can effectively reduce the response time when the visit quantity is large.
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Computer Engineering. 2011, 37(12): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2011.12.027
To solve the deficiency in efficiency, complication and utility of the existing main sensing algorithms, this paper analyzes a way of spectrum sensing derived on waveform, based on which it puts forward a combined detection method associated with energy sensing. According to the numerical analysis and simulation results, it concludes that the combined sensing can effectively detect the spectrum hole and meanwhile, overcome the problem of poor detection effect under low signal to noise ratio, which makes it better than waveform detection and energy detection in detection efficiency, reliability, stability and other performance.
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Computer Engineering. 2011, 37(12): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2011.12.028In order to adapt to resources-constrained Wireless Sensor Network(WSN), an improved Fusion Algorithm of Hierarchical Data in Cluster for WSN is proposed on the basis of the Principal Component Analysis(PCA). Self-learning weighted method estimates measured variance of every sensor. The linear unbiased minimum variance estimate method is adopted, which is able to reduce the errors of measured datum of the cluster sensor nodes. The formulas of comprehensive support degree of each sensor and data fusion are obtained according to the PCA method. The application example and simulation results prove that the method is effective and reliable.
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Computer Engineering. 2011, 37(12): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2011.12.029
This paper addresses the problem of Signal-to-Noise(SNR) estimation in wireless Single Input Multiple Output(SIMO) channels. It implements four algorithms of SNR estimation, expectation-maximization estimator, second-and fourth-order moments estimator, fourth-order moment estimator and sixth-order estimator, in common simulated channels and analyzes the reasons that may affect performances of the algorithms, such as the number of the antennae, modulation mode, noise power and so on. Simulated performances are compared with a published Cramer-Rao Lower Bound(CRLB). It also analyzes the complexity of the algorithms.
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Computer Engineering. 2011, 37(12): 88-91. https://doi.org/10.3969/j.issn.1000-3428.2011.12.030This paper proposes a distributed object oriented algorithm based on energy——weighted Projections onto Convex Sets(POCS) to solve the problem that POCS is not accurate and stable. Based on the variance of circle, the variance of line is derived, and a relationship equation between the variance and the pace of POCS is set up to realize weighted POCS. To control paces to different circles and lines, the influence of noise is reduced. It is proved that weighted POCS is more accurate and stable.
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Computer Engineering. 2011, 37(12): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2011.12.031Based on analysis of RFCOMM transport protocol, connection model and procedure of communication, this paper presents a RFCOMM-L2CAP asynchronous communication structure based on Finite State Machine(FSM) and a multiplexing model of L2CAP channel as RFCOMM unique transport layer, maintaining a reference relationship between RFCOMM connections and L2CAP logic channel through asynchronous handling of event, optimizing the efficiency of information exchange and real time between layers of Bluetooth protocol stack.
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Computer Engineering. 2011, 37(12): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2011.12.032Considering the heterogeneous features of the peer in Peer-to-Peer(P2P) media streaming system. In this paper, the system nodes are divided into different levels. A neighbor peer selection algorithm is proposed based on random walk, and the transition probability matrix is calculated through the Metropolis-Hastings methods in order to choose a higher level of system nodes with greater probability. Moreover, the overlay network topology optimization algorithm is elaborated. Simulation results demonstrate that the algorithm can improve the peers’ cooperation, reduce system latency, and has a strong robustness in dynamic network environment.
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Computer Engineering. 2011, 37(12): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2011.12.033This paper proposes an Enhanced Rate Degradation Call Admission Control(ERDCAC) algorithm for multimedia wireless network to maximize Grade of Service(GoS). The degree of maximum degradation for Wide-Band(WB) when new Narrow-Band(NB) arrives is optimized. It develops a Markov model to analyze ERDCAC, and along with the measurements of call arrival rates of all traffics, the optimal threshold variable to acquire the maximal GoS is obtained by using exhausting search. Numeric results show that ERDCAC acquires better GoS compared with traditional rate regulation Call Admission Control(CAC) scheme.
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Computer Engineering. 2011, 37(12): 101-103. https://doi.org/10.3969/j.issn.1000-3428.2011.12.034Considering Internet data stream dynamically in large volumes, this paper proposes a traffic classification method using data stream mining techniques, named Concept-adapting Very Fast Decision Tree(CVFDT). CVFDT is capable of processing dynamic datasets, coping with concept drift and updating the model catering to incoming data. The approach and naive Bayes method on network traffic data stream sets are tested, which has 12 significant attributes. Experimental result shows that the approach gets high performance on classification accuracy and spatial stability compared with naive Bayes method.
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Computer Engineering. 2011, 37(12): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2011.12.035This paper studies the blind multi-user detection algorithm of Code Division Multiple Access(CDMA) system under the condition with heavy Multiple Access Interference (MAI), proposes a new blind adaptive multi-user detection algorithm based on Kalman filter. The algorithm can estimate the unknown noise statistics characteristics on-line while conducting state filtering, and an efficient iterative implementation that provided very fast convergence under this representation is presented. Simulation results show that the new algorithm has the better tracking capability under the dynamic environment and convergence ability than Least Mean Square(LMS) algorithm and Recursive Least Squares(RLS) algorithm.
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Computer Engineering. 2011, 37(12): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2011.12.036For mobile Ad Hoc networks vulnerable to wormhole attack problem, it proposes a routing protocol based on the best links——MSRP secure routing protocols, including the neighbor detection, authentication, key negotiation and communication process, to seek balance between security and performance in the case of the settlement agreement in OLSR security problems. MCPK-based security with routing protocols, OLSR neighbor detection stage by the introduction of secure authentication mechanisms to prevent wormhole attacks. Experimental results show that with the increase in the length of an encrypted channel, wormhole attack detection rate is significantly increased, the solution can better prevent and detect wormhole attacks.
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Computer Engineering. 2011, 37(12): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2011.12.037According to the evaluation of trust for the subject, a subjective trust model based on the interval is proposed. It refers to the convex curve of the interpersonal trust relationship in the sociology, and introduces the weights of expert evaluation. Learning from the weighted average of the evaluation on the subject, a model on the subject by scoring method is established. The trust of the subject is divided into six intervals by trust interval, and example analysis confirms the validity and rationality of the model which uses the trust interval to show the trust degree.
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Computer Engineering. 2011, 37(12): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2011.12.038In order to get rid of the capital safety resulting from the fraud of the campus card, this paper proposes a procedure of fraud detection named “reconciliation-pretreatment-detection with neural network”. A new algorithm to detect campus cards which has abnormity transactions is designed, and a model for fraud detection of campus card is built on the basis of neural network algorithm. Test results show the detection model possesses preferable practicability and self-adaptability.
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Computer Engineering. 2011, 37(12): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2011.12.039The information security issues of Radio Frequency Identification(RFID) system at present urgently needs solution. A new scheme is proposed that the chaotic encryption of information security in RFID system, in order to increase the security of RFID secure mechanism without affecting the operation efficiency. The Logistic mapping whose initial value is variable is used to generate chaotic cipher sequence, and then date is encrypted. Related analysis and simulation experiment verifies that this RFID secure mechanism easily realizes, operates fast and can completely meet the security demand of the RFID systems.
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Computer Engineering. 2011, 37(12): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2011.12.040This paper proposes an image processing method which is based on Bidimensional Empirical Mode Decomposition(BEMD). BEMD is applied in watermark embedding and extraction. The watermark is scrambled and the original image is divided into sub-images, then it applies BEMD to scrambling watermark and sub-images to obtain the corresponding Intrinsic Mode Function(IMF). The IMF of the watermark is embeded into each sub-image of the original image to complete the watermark embedding. Experimental results prove that this algorithm improves in the embedding watermark quantity and has a high robustness. At the same time, it has no visibility and high security.
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Computer Engineering. 2011, 37(12): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2011.12.041Sybil attack is a particularly harmful attack against Wireless Sensor Networks(WSN). They defeat many functions of the WSN such as data fusion, fair resource allocation etc. So it is important to defense and detect Sybil attack. This paper presents a solution scheme for Sybil attack detection based on the Hop-Count-Ratio Localization(HCRL). The main idea of this scheme is that the identities the Sybil nodes created have the same physical location, so the Sybil nodes can be detected through the HCRL optimization algorithm. Sybil attack has a significant influence on the network performance and the network performance is obviously improved after the detection. Simulation experiment and performance analysis shows that the scheme is effective and low-overhead.
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Computer Engineering. 2011, 37(12): 125-126. https://doi.org/10.3969/j.issn.1000-3428.2011.12.042
This paper proposes a new watermark algorithm based on the chaotic sequence to solve the security problems of Yeung-Mintzer algorithm and it has a significant improvement on the image invisibility and the tamper detection rate, while retains the other advantages. The method is intended for use in image verification applications, where one is interested in knowing whether and where the content of an image is altered maliciously. Theoretical analysis and experimental results prove that this algorithm has a great practicability and can be used for legal evidence image and medical image.
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Computer Engineering. 2011, 37(12): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2011.12.043According to the fact that SVO logic lacks relative axioms of judging and verifying the validity of certificates and the security proof of authenticated exchange protocols, this paper advices to estimate the protocols security from the aspect of ability of attackers by combining Dolev-Yao threat model with the extension of SVO logic which proves that Mangipudi protocol is not immune from impersonation attack and has no the security property of forward secrecy. Then a provable security scheme which overcomes all above flaws in the Dolev-Yao threat model is proposed.
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Computer Engineering. 2011, 37(12): 130-132. https://doi.org/10.3969/j.issn.1000-3428.2011.12.044
According to Data Encryption Standard(DES) key schedule characteristics and abandoning the original parity bit, this paper receives 16-rounds subkey by transposing from the remaining 56 bit. Based on the order of each subkey and absent bit, it properly sets plaintext difference and key difference, and obtains 5-rounds differential characteristic. Depending on related-key differential method, it analyzes 5-rounds DES and gets 9-rounds DES related key Boomerang attack. The attack time complexity is about 231 times encryption and decrypted operations. The data complexity is 240.
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Computer Engineering. 2011, 37(12): 133-136. https://doi.org/10.3969/j.issn.1000-3428.2011.12.045Different from the traditional Probabilistic Packet Marking(PPM), according to the problems in PPM, such as loss of marking information, difficulty to reconstruct attack paths, low accuracy, and so on, a novel DPPM method is proposed and network simulation software (NS2) is used to verify the performance and efficiency of the method by constructing simulation environments. In comparison with PPM methods, simulation results show that DPPM has excellent accuracy and efficiency.
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Computer Engineering. 2011, 37(12): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2011.12.046
A video object watermark algorithm using Scale-Invariant Feature Transform(SIFT) features and video segmentation based on spatio-temporal information is proposed. The watermark message is embedded in Discrete Cosine Transform(DCT) domain of the detected video object region. Before embedding the watermark, the object SIFT features are detected and registered in advance. In the detecting scheme, the object is corrected by using feature matching, and the message can be detected. Experimental results show that the algorithm can well protect the video object and be robust to geometric attacks and usual signal processing attacks.
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Computer Engineering. 2011, 37(12): 140-143. https://doi.org/10.3969/j.issn.1000-3428.2011.12.047Aiming at the problem of single-point failure which may lead to loss of credentials and poor fault-tolerance in distributed storage strategies, an improved distributed storage strategy is proposed. Using distributed storage strategies as a basis, exiting data structures is used to support the design of the credential storage strategy. Based on the idea of resource redundancy, multiple credential copies and credential recovery mechanism are employed. Experimental results show the storage strategy has increased fault-tolerance and balanced storage.
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Computer Engineering. 2011, 37(12): 144-146. https://doi.org/10.3969/j.issn.1000-3428.2011.12.048Nonlinear manifold learning has the advantages of accurately reflecting the real nature of nonlinear data and effective dimension reduction. But it can not effectively handle ever-increasing speech data set and can not make full use of information got from the training process in speech emotion recognition. This paper presents a speech emotional feature dimension reduction method based on incremental manifold learning, which employs Isometric Mapping(ISOMAP) to reduce the feature dimension of training sample to target dimension, and obtains the low-dimensional features of test sample by using the incremental manifold learning method. Experimental result shows that the method has lower computational complexity and achieves better recognition performance.
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Computer Engineering. 2011, 37(12): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2011.12.049The navigation interactive methods for mobile phones have some drawbacks which contain inconvenient operation, difficult imple- mentation and high cost. Aiming at these problems, this paper proposes a novel human-computer interaction system combining with shin color model, intensity transformation and geometrical characteristic. It collects serial images of thumb moving by the front camera of mobile phone, and judges the hue of the image in YCbCr color field. It adjusts the intensity of the image based on object and background gray characteristic, and calculates the geometric centre by the centre of gray value. It finds the relative position of thumb moving in the instruct plane. Experimental results demonstrate that the interaction can recognize four main instructs and twelve auxiliary instructs friendly and quickly.
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Computer Engineering. 2011, 37(12): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2011.12.050For the large differences of syntactic structure between Chinese and Uyghur, it composes rules to reorder the structure of Chinese sentences to that of Uyghur. For the large morphological differences between Chinese and Uyghur, it splits Uyghur words into stems and affixes, that is, morphemes, to train the statistical model. Meanwhile, it tests the effects of splitting granularities on translation performance. Experimental results show Chinese sentence reordering and splitting Uyghur words into morphemes can effectively improve the performance of translation system.
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Computer Engineering. 2011, 37(12): 153-154. https://doi.org/10.3969/j.issn.1000-3428.2011.12.051Multi-cell adhesion shape recognition is a key problem in the field of image recognition. The improved threshold segmentation and eight direction boundary description strategies are proposed to locate the cells in this paper, and then the shape of those cells is recognized by separating each adhesion based on polygonal angle-offset method. Experimental results show that this method is appropriate to the complex situation where multi-cell conglutination separation and each cell’s shape recognition are needed. This system’s multi-cell conglutination separation accuracy is 95.3%, shape recognition accuracy is 97.6%, and each recognition of cell costs 0.03 s.
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Computer Engineering. 2011, 37(12): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2011.12.052This paper uses continuous geometric features to present motion sequence and obtain their subspace respectively. Due to the difference of complexity between different categories of motions, their intrinsic dimensions are not the same. It introduces a method which is able to measure the distance between subspaces with different dimensions. Experimental results demonstrate that improved continuous geometric features are efficient and it outperforms than supervised method, in addition, its response time and storage space are quite low.
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Computer Engineering. 2011, 37(12): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2011.12.053In order to solve the greatly dimension of word frequency and sparse matrix, this paper proposes a multi-document summarization method based on sub-topics area partition. It uses HowNet to obtain concept of word, constructs Concept Vector Sapce Model(CVSM) replace traditional Word Frequency Vector Space Model(WFVSM). After constructed CVSM, the document is segmented into several units in terms of the sub-topics in the document. The most representative sentences in each sub-topic unit are selected as the summary sentences. Experiment results prove the validity of the method.
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Computer Engineering. 2011, 37(12): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2011.12.054To improve the efficiency of coordinate descent method when it is applied to linear Support Vector Machine(SVM), Powell algorithm is applied to linear SVM. The one-variable sub-problems produced in searching process are solved by a global Newton algorithm. In inter iterations, it updates one component of w by solving a one-variable sub-problem while fixing other components. In outer iterations, it is judged, according to the judgment conditions, whether the procedure searches along accelerated direction or not and whether the accelerated direction can substitute one of anterior search directions or not. Experimental results on UCI dataset show Powell algorithm converges fast and its accuracy is higher than that of coordinate descent method and smooth SVM .
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Computer Engineering. 2011, 37(12): 164-165. https://doi.org/10.3969/j.issn.1000-3428.2011.12.055
This paper proposes a new Linear Discriminant Analysis(LDA) for face recognition based on the graph embedding and regularization. The unsupervised optimal class separate criterion is built, and it proposes a method to get this projection vector on the graph embedding frame. It can get a huge save of computational consumption and utilize the class information of samples more effectively. Experimental results demonstrate the effectiveness and efficiency of this method.
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Computer Engineering. 2011, 37(12): 166-169. https://doi.org/10.3969/j.issn.1000-3428.2011.12.056This paper proposes an Active Support Vector Machine(ASVM) algorithm based on similarity fusion. It uses unlabeled samples, labeled samples, combines with Support Vector Machine(SVM) method to achieve active learning. Experimental results show, compared with the general ASVM, it can reduce the number of labeled samples effectively and inhibit the isolated samples of impact on the premise of keeping correctness of the classifier and it also has a higher classification accuracy in the same number of labeled samples.
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Computer Engineering. 2011, 37(12): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2011.12.057
This paper constructs parallel model based on Open Multi-processing(OpenMP) and parallel model based on Message Passing Interface(MPI) in multi-core environment, and constructs parallel model based on MPI and parallel model based on MPI+OpenMP in the multi-core clusters. The preferred strategy of dynamic ant colony and the strategy of sub-cycle exchange are presented. Finding optimized path of road is used to compare the three models. Experimental results show that MPI-based model run faster and get higher speedup than OpenMP-based model. In multi-core environment, hybrid model of MPI+OpenMP gets higher speedup than MPI-based model with more processes.
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Computer Engineering. 2011, 37(12): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2011.12.058Aiming at the problem of walking stability in humanoid robot, this paper introduces Zero Moment Point(ZMP) theory, the reaction force of ground must be inside the support polygon to maintain dynamic balance. The area of stable region and stability margin in single support phase and double support phase are deduced. Humanoid robot biped walking model with two different shapes is established, and a series of contact is set between sole and ground. The contact forces ware got through Automatic Dynamic Analysis of Mechanical System(ADAMS) software after analyzing simulation and the forces of the sole during walking, it gets reasonable bipedal shape.
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Computer Engineering. 2011, 37(12): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2011.12.059A new expression image feature extraction and recognition method based on Locally Linear Embedding(LLE) and fisher criterion, named FSLLE, is proposed. The algorithm dynamically determines the local neighborhood size by using the relationship between its local estimated geodesic distance matrix and local Euclidean distance matrix and effectively integrated the face manifold local structure information with the labels’ information by adjustable factor. The proposed method is tested and evaluated using the JAFFE face expression database. Experimental results show that FSLEE validate the proposed approach and is more powerful for expression recognition.
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Computer Engineering. 2011, 37(12): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2011.12.060In order to reduce the multi-channel average delay time in multi-channel data broadcast, this paper proposes a multi-channel data broadcast schedule algorithm based on greedy strategy, a multi-channel data allocation method that rationally allocates data items to different channels in order to minimize the Multi-channel Average Expected Delay(MCAED). And within each channel, the Log-time algorithm which is supposed to be optimal in single channel is adopted. Experimental results show that the algorithm can get the near-optimal solution under a variety of circumstances.
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Computer Engineering. 2011, 37(12): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2011.12.061
This paper presents an online adjusting method of Proportion Integration Differentiation(PID) parameters based on Quantum Neural Networks(QNNs). By designing a controlled quantum rotation gate, a quantum neuron model is constructed, including two kinds of design parameters: rotation angle of qubits phase and its control range. A quantum neural networks model based on quantum neuron is proposed. By using gradient descent algorithm, a learning algorithm of the model is designed. Experimental results show that both the adjusting ability and the stability of QNNs model are superior to that of the Back Propagation(BP) networks.
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Computer Engineering. 2011, 37(12): 185-186. https://doi.org/10.3969/j.issn.1000-3428.2011.12.062
In the multi-platform multi-sensor tracking system, this paper presents a deviation registration and target tracking algorithm with a fading factor. A new registration deviation model is built based on the deviation registration and the target stats, a fading factor is introduced to tracking process in order to improve the system robust, due to it can be fast response to abrupt change of states. Simulated results show that the algorithm can make the system deviation estimates rapidly converge to near the real value, and it has good adaptability and can improve the system’s overall tracking precision when the deviation is mutation.
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Computer Engineering. 2011, 37(12): 187-189. https://doi.org/10.3969/j.issn.1000-3428.2011.12.063An image de-noising method based on second derivative operator to noise location can de-noising impulse noise effectively, but it is not very good to remove Gaussian noise. An image de-noising method based on wavelet transform has the ability to remove Gaussian noise while it hardly de-noises impulse noise. An image de-noising method based on second derivative operator and wavelet transform has some advantages. It has better effect on removing impulse noise, Gaussian noise and impulse-Gaussian mixed noise and it decreases the difficulty of threshold selection, which is good to improve the accuracy of image de-noising. Experimental result shows that this method is effective and feasible.
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Computer Engineering. 2011, 37(12): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2011.12.064This paper focuses on digital images which are acquired using scanners, and proposes a robust sources identification technology. The method is based on using color features, image quality features, and neighborhood prediction features of scanned image samples. These features are used to design source identification algorithm in the form of a feature vector. Using Support Vector Machine(SVM) to determine the brand or model of scanner used to capture each scanned image. Experimental results demonstrate that the proposed method can effectively identify the correct scanner brands/models with higher accuracy and has better robust, compared with previous methods.
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Computer Engineering. 2011, 37(12): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2011.12.065
In the image registration process, the computational complexity is the major problem of the traditional Hausdorff distance algorithm. This paper proposes an image registration fast algorithm based on Hausdorff distance. Edge examination to the reference image and the image is registration, and then chooses a template, sets a variable threshold to improve the Hausdorff distance algorithm so as to reduce the amount of unnecessary to achieve rapid match. According to the matched data, it carries on the scale transformation and the rotation operation to the image, enables two images registration in the space. Experimental result proves that, comparing with the traditional matching algorithm, the computational complexity reduced greatly.
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Computer Engineering. 2011, 37(12): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2011.12.066To resolve the problem that the traditional de-noise methods will blur the detail of image, this paper introduces a new method to de-noise the image noise in low light. The method reduces the noise with the advantage of human eyes, according to the different noise level with the corresponding illuminance. The function and flow chart is shown and parametric of function is decided by experiment. And the result of experiment shows that the method reduce the noise and the detail of the image is not blurred.
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Computer Engineering. 2011, 37(12): 199-200. https://doi.org/10.3969/j.issn.1000-3428.2011.12.067Aiming at CT image segmentation, an improved algorithm is proposed, which reduces the dependence of traditional knockout method on the manual input, and improves its robustness. Use the grayscale information of CT image to modify the original input. Add the processing of adaptive threshold and region grow to rectify the foreground, a negative gradient searching to correct the background, and the transformation of color space to get a new equation about alpha in the signal channel. Experimental results show that this improved model has a better behavior.
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Computer Engineering. 2011, 37(12): 201-203. https://doi.org/10.3969/j.issn.1000-3428.2011.12.068Aiming at the problem of the low accuracy of conventional airport main track detection method, this paper presents a method of the airport targets detection for Synthetic Aperture Radar(SAR) images. It uses Fuzzy C-Means(FCM) clustering to segment the airport. It utilizes morphology filtering and removing the connected domains whose number of pixels is less than the threshold to remove some interfering targets in the background. Then it uses Hough transform to detect lines in the edge image. The postprocessing is based on the characteristic that the runways of the airport are parallel pairs and the fusion method. Experimental result indicates that the algorithm can detect the runways of the airport successfully, and it has significant practical value.
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Computer Engineering. 2011, 37(12): 204-205. https://doi.org/10.3969/j.issn.1000-3428.2011.12.069This paper presents a image denoising method based on Non Subsampled Contourlet Transform(NSCT) threshold and P-Laplace diffusion. The denoising image by threshold method of NSCT translational invariant is obtained. The NSCT coefficients which are set to zero by the threshold procedure are retained. Then the P-Laplace diffusion method is applied directly with the reconstruction image from the retained NSCT coefficients. The diffusion image is fused with the denoising image which by threshold method. Numerical results show that this method can effectively keep the original image texture details, and reduce the Gibbs shaken phenomenon of image noise.
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Computer Engineering. 2011, 37(12): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2011.12.070On the building image processing with Scale Invarint Feature Transform(SIFT) descriptor, there will be a large number of falsely matching points. Aiming at this problem, the color and global information is introduced to improve the performance of SIFT descriptor. It introduces l1l2l3 model which is robust against light change and build log-polar coordinates. For each key point, it builds circular neighborhood to cumulate the value of l1, l2, l3. Color invariant descriptor can be constructed. Global descriptor can be constructed with the same method. The Euclidian Distances of SIFT color invariant descriptor and global descriptor will be as similarity measurement. Experimental results indicate that the improved SIFT algorithm can reduce mismatch probability of building images and improve matching results greatly.
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Computer Engineering. 2011, 37(12): 209-211. https://doi.org/10.3969/j.issn.1000-3428.2011.12.071More and more medical image files are produced today, and they are difficult to storage, management and find. Aiming at this problem, this paper puts forward a feature-based medical image data storage model. The model is an object oriented-mesh mixed model, which combined the object oriented model of the object principles and message mechanisms with the chaining storage of mesh model, store the image itself and the features as an object, realized the image information fast storage and query. Experimental result indicates that the model storage efficiency, query speed and has good usability and scalability.
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Computer Engineering. 2011, 37(12): 212-214. https://doi.org/10.3969/j.issn.1000-3428.2011.12.072Aiming at the problem of existing algorithm testing precision and edge position is not accurate, this paper proposes a method for pavement cracks extraction using iterative clustering algorithm based on manifold distance. The method calculate the manifold distance between two data points, and a criterion function used to express the clustering target is designed, then solve the criterion function optimization problem by iterative optimization. All the data points are divided into two clustering that the background and objectives.using image processing algorithms extract pavement cracks information. Experimental results show that the continuous cracks can be stable and effectively extracted. It is beneficial for the automatic detection of pavement cracks.
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Computer Engineering. 2011, 37(12): 215-217. https://doi.org/10.3969/j.issn.1000-3428.2011.12.073This paper presents a Fourier analysis method for target detection in side-scan image. Using horizon line, vertical line, slope 45° line and slope 135° line spectral mask, the projection of side-scan sonar image in these orientation is obtained. Based on the sum of energy of four orientation projections, a threshold is set to judge target existing, and the position of target is also given. Results show that the method has a perfect performance for regions of interest (target) detection of side-scan sonar image with strong texture.
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Computer Engineering. 2011, 37(12): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2011.12.074Aiming at the problem that Technical Performance Measure(TPM) only accounts for the achieved performance instead of both the achieved and unmet performance, it is impossible to reflect the aggregated risk. This paper extends the technology category in TPM. A new kind of technology is added to the traditional TPM and the calculating formula is given. The proposed TPM is based on two concepts: the unmet performance and the degree of difficulty with the unmet performance. In order to demonstrate how to use this method, two applications are given.
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Computer Engineering. 2011, 37(12): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2011.12.075In Just in Time(JIT) production model, large coils storage study is to resolve a multi-objective optimization problem, and traditional manual methods do not work. A storehouse goods amount calculation method is designed based on production plan and safe stock coefficient. And a cluster analysis algorithm is given for allocation of shelves. A decision tree is structured to solve the multi-objective optimization problem. These methods pass the test of practice, raise the warehouse efficiency and the utilization rate of storehouse, and meet the enterprise requirements, such as safety production, good quality and high efficiency and reduced waste.
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Computer Engineering. 2011, 37(12): 224-225. https://doi.org/dengweiqiang-163@163.com
To solve the problem of spectral deviation for Time-Varying Auto-Regressive(TVAR) model parametric spectrum estimation, this paper proposes a TVAR parameter estimation method based on Genetic Algorithm(GA) and combined objective function and the method is used to model the flight vibration time series and its spectrum estimation. An initial estimation of the parameters is acquired by the U-C algorithm; through modern spectrum estimation theory and the necessary condition of extreme value for continuous function, a constraint equation of model parameters is derived and a combined adaptability function is constructed; the GA is used to optimize the initial parameter estimation. Application results verifies the efficiency of the method.
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Computer Engineering. 2011, 37(12): 226-229. https://doi.org/10.3969/j.issn.1000-3428.2011.12.077According to multi-cell equalization problem in the charging and discharging process of series connected li-ion battery pack, this paper designs an intelligent fast charging and discharging research scheme for li-ion battery pack that can realize energy’s non-dissipative equalization. The premise and background are introduced. It proposes the overall structure and non-dissipative equalization circuit of charging and discharging management method study. Some design modules are expatiated clearly, including the sample circuits of the scheme’s voltage, current and temperature, charging and discharging control and MOSFET driver circuits. Experimental results show that this scheme meets the expected requirements.
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Computer Engineering. 2011, 37(12): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2011.12.078The direction of iterating is decided by the remaining angle results, taking the imported way of pre-determined of the direction of rotating and model factor, achieving the pre-determined of the iteration with the angle’ binary code, merging some of the hardware circuits and saving resources, improving the algorithm’s speed and accuracy. Experimental results show that the Direct Digital Synthesis(DDS) output signal spectrum spur is small and the Spurious Free Dynamic Range(SFDR) is improved by 20 dB, the hardware resources are saved by 28％, calculation error reaches 10-5 and effectiveness of these methods in speed, accuracy and low consumption is shown.
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Computer Engineering. 2011, 37(12): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2011.12.079Considering inconvenience of downloading or upgrading by Background Debug Mode(BDM) in the traditional ways of the application programs, the special BootLoader which updates application online based on CAN bus and CAN Calibration Protocol(CCP) is designed. Emphasis is paid on the design of BootLoader and the implementation of CCP on between vehicle control unit and personal computer. The vehicle test proves that the BootLoader boots the application accurately, downloads and upgrades correctly and facilly.
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Computer Engineering. 2011, 37(12): 236-238. https://doi.org/10.3969/j.issn.1000-3428.2011.12.080To meet the need of expression and share of parts information among the parties in collaborative product commerce, a method of expression and share of parts information oriented to collaborative product commerce is proposed. The composition of parts feature and the relationship between them are analyzed, and a parts information feature model is established based on feature modeling technology. The model is transformed into a unified XML Schema, and the basic transform rules are explained. A collaborative product commerce platform of sharing and transferring the parts information is proposed. Under the check of the XML Schema, the parts information is described by XML and is mapped by XSL, the platform meets different users’ need of display and achieves the share and transfer of the parts information. Application example shows the effectiveness and feasibility of the method.
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Computer Engineering. 2011, 37(12): 239-241. https://doi.org/10.3969/j.issn.1000-3428.2011.12.081Because negotiators have to wait each other in the course of negotiation, so the one-to-many automated negotiation is inefficiency. In order to reach the best agreement in the least time for the negotiators, this paper proposes a coordination strategy based on fuzzy theory which can make the course continuative. Taking advantage of the coordinating Agent, this strategy can create and pull out the negotiation threads flexibility and in the course of negotiation, it updates the believes of the negotiators, so this strategy supports the continuous negotiation in open and dynamic environment and increases the efficiency substantially. Experimental result shows that the negotiation time and utility are optimized in the negotiations progress.
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Computer Engineering. 2011, 37(12): 242-244. https://doi.org/10.3969/j.issn.1000-3428.2011.12.082This paper proposes the method of large file storage by blocking partition based on Hadoop and massive agricultural resources retrieval method, and establishes the massive agricultural data management platform based on Hadoop. Test and practice results show that this platform provides a technical direction for the realization of massive, distributed, heterogeneous unified agricultural knowledge resources, efficient organization and management.
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Computer Engineering. 2011, 37(12): 245-247. https://doi.org/10.3969/j.issn.1000-3428.2011.12.083In consideration of the memorizer which uses the flash memory as storage media, this paper proposes a RS algorithm to adapt to different resolutions, and a package of comprehensive approach is designed which has the full ability of recording storage and reading of the system. It solves the problem of lacking the reliable when the data in flash memory is rotating, and improve the quality of the system. Each process can remedy 3 Byte random errors, under the condition of 640×480 pixel, the maximum by page of correcting errors is up to 72 Byte, signal-to-noise ratio increases by more than 2 dB.
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Computer Engineering. 2011, 37(12): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2011.12.084According to the correlation noise modeling between side information and source in the Distributed Video Coding(DVC), a novel refinement method based on Multi-Hypothesis Motion-Compensated Prediction(MHMCP) is proposed. It generates original Side Information(SI) by traditional methods, uses bi-directional motion estimation to generate motion compensated blocks, and linearly combines them to generate new SI. Experimental results show that the proposed strategy with the advantage of low algorithm complexity can significantly increase the accuracy of SI, thereby effectively improves the RD performance of DVC.
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Computer Engineering. 2011, 37(12): 251-254. https://doi.org/10.3969/j.issn.1000-3428.2011.12.085
Fast motion estimation algorithm based on the inputted stream information is proposed for the down-sizing video transcoding. The predicted motion vector is synthesized by using the motion vectors and coefficients of the inputted stream. The conformity of the motion vectors in the related region is analyzed. The search strategy of motion estimation is adjusted according to the predicted motion vector, the conformity and the frame activity. Experimental results show that, this algorithm reduces above 20% of encoder time as compared to the diamond search algorithm, while it maintains a reasonable video quality. It also achieves higher performance and better quality than AMVR-DIM algorithm.
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Computer Engineering. 2011, 37(12): 255-257,261. https://doi.org/10.3969/j.issn.1000-3428.2011.12.086
Aiming at the not timely monitoring for the change of temperature and humidity when grain is in store, which causes the grain in a moldy condition, this paper accomplishes the monitoring system for condition of stored-grain which combines temperature and humidity inspection, and the wireless data transmission by WSN technology. It introduces the system architecture, hardware and software design and monitoring platform design. Proved through practice, this system is featured for high stability, anti-sepsis, mould proof, lightning protection, low-consuming and low-cost, which ensures the storage security effectively.
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Computer Engineering. 2011, 37(12): 258-261. https://doi.org/10.3969/j.issn.1000-3428.2011.12.087An adaptive genetic algorithm with the thought of simulated annealing algorithm is designed to resolve the problem of auto components logistics network optimization plan. The parameters of genetic operators can be changeable based on the method of simulated annealing algorithm. The contrast of the different optimization results show that the adaptive genetic algorithm can implement the optimization process and demonstrate good adaptability.
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Computer Engineering. 2011, 37(12): 262-264,267. https://doi.org/10.3969/j.issn.1000-3428.2011.12.088The memory management unit and the Cache of S3C2440A are introduced. An experimental method is designed to measure the influence of Cache on the instruction executive speed while the cache is disabled or enabled. Plenty of experiments are accomplished for instructions located in SDRAM or SRAM under three recommendatory CPU frequencies, data are analyzed and processed. Experimental results show that it has great influence to improve instruction mean executive speed when the cache is enabled.
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Computer Engineering. 2011, 37(12): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2011.12.089A color indicator detection algorithm under variant light condition and variant background is presented. Background image is chosen based on the similarity between consecutive frames of a video in L channel of Lab color space. Image differentiation on any frame and the background can identify the motion region, which can reduce the search area for the color indicator. The convex hull of motion region is found and some samples are taken. By assigning the weight, seeds can be determined using clustering method. Region growth is implemented by applying Bayesian decision with minimal error ratio. Experimental result shows that the proposed method is applicable to more conditions and produces compared with traditional color-threshold vector method.
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Computer Engineering. 2011, 37(12): 268-269,272. https://doi.org/10.3969/j.issn.1000-3428.2011.12.090
Test Vectors Applied by Circuit-under-test itself(TVAC) is a new Built-in Self-test(BIST) scheme. Two different TVAC structures for synchronous full scan sequential circuits are presented. Experimental results on ISCAS89 benchmark circuits demonstrate that, compared with the weighted-random-pattern test and Circular Self-test Path(CSTP) method, the TVAC scheme can reach higher fault coverage with smaller test vectors.
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Computer Engineering. 2011, 37(12): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2011.12.091A calibrating method based on tetrahedron interpolation is proposed. Because the sampling data is irregularly distributed in L*a*b* space, it is hard to construct 3D look-up-table for color conversion, which restricts the use of 3D interpolation in calibration algorithms. Consequently, an optimal vertex-finding algorithm in L*a*b* space is developed for constructing tetrahedrons, and the tetrahedron with smallest volume and enclosing the given point are selected, which is used to take the conversion from L*a*b* to device space. Experimental result shows the average error is less than regression and neural network method, which indicates that it can be used to calibrate most of the color devices.
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Computer Engineering. 2011, 37(12): 273-275,278. https://doi.org/10.3969/j.issn.1000-3428.2011.12.092
On the basis of the analysis for Intergroup Complementary(IGC) code and zero correlation zone complementary code, a modified IGC code is proposed to adapt M-ary orthogonal code spreading spectrum system or quasi-synchronous CDMA system. Theoretical research and simulation results show that the main advantages of the modified IGC code are as following: The code sets of the modified IGC code is more than IGC code under the same code length. The zero correlation zone length is longer than the intergroup IGC code, but shorter than the intergroup IGC code. Under the same code length, the auto-correlation performance of the modified IGC code is better than that of the IGC code, and both are of similar cross-correlation performance.
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Computer Engineering. 2011, 37(12): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2011.12.093Based on Bark wavelet transform, a voice activity detection algorithm is proposed to improve the performance in noisy environment. This paper introduces a scale parameter into the nonlinear mapping, utilizes the singularity of the Bark wavelet transform coefficients in different sub-bands to construct a VAD parameter, and effective threshold selection rules are validated by simulations. Experiment results show that the accuracy of this algorithm is evidently heightened, and its robustness is enhanced, compared to some traditional algorithms such as short-time energy and cepstral distance.
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Computer Engineering. 2011, 37(12): 279-281,284. https://doi.org/10.3969/j.issn.1000-3428.2011.12.094
For detecting the potential common errors of integrated circuit designs quickly and efficiently, this paper introduces a novel error defection approach based on static analysis. The proposed approach can find errors, such as deadlocks in state machines, errors in pin configuration, by automatically deriving information about the behavior of Register-Transfer Level(RTL) design under verification. Experimental results show that compared with other verification methods, the static method can find errors automatically, efficiently and accurately. It can be reused for any other RTL design to detect errors before simulation.
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Computer Engineering. 2011, 37(12): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2011.12.095An effective algorithm is proposed to segment moving object in compressed domain and pixel domain method combined. In this algorithm, a space-time filtering and accumulation is used to process the MV(Motion Vector) field, and the method of MV spatial differences is used to extract the region of moving object in compressed domain. After that the extracted region is expanded appropriately in pixel domain, and in pixel domain the more accurate moving object is segmented by using the MRF(Markov Random Field) model. Experimental results show that the segmentation algorithm is efficient and segmented moving object is complete and accurate.
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Computer Engineering. 2011, 37(12): 285-286. https://doi.org/10.3969/j.issn.1000-3428.2011.12.096To solve the problem that the communication delay widely exists in distributed sensor network, this paper develops the original asynchronous track fusion algorithm and proposes a new asynchronous track fusion algorithm based on network delay. The algorithm can simulate communication delay. Besides, it can automatically track and examine the sensors which have delay and take corresponding actions. The new algorithm provides higher adaptability and practicability. The impact of the data transmission delay is analyzed and the effect of delay is compared through simulation.
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Computer Engineering. 2011, 37(12): 287-290. https://doi.org/10.3969/j.issn.1000-3428.2011.12.097In order to overcome the shortcomings that conventional detection methods highly depend on the detailed configurations of the virtual machine systems, a detection program is designed and implemented, which can detect the virtual machine via the variance of relative instructions throughput. This method can detect virtual machine successfully and require only a little knowledge of target machine’s hardware configurations, has little dependence on different hardware configurations.
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Computer Engineering. 2011, 37(12): 291-292. https://doi.org/10.3969/j.issn.1000-3428.2011.12.098This paper studies the principle of existing network information content recovery systems, and various improvement strategies. And then based on the situation that current network information content recovery system has not taken full advantage of computing resources and the high popularity of multi-core processor, this paper proposes network information content parallel recovery model based on multi-core processor. The model de-multiplexes high flow of data packets to multi-processes and makes full use of computing resources to enhance the bandwidth without additional hardware resources. Experimental results show that the realization of the model can effectively improve the throughput.
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