20 December 2010, Volume 36 Issue 24
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Computer Engineering. 2010, 36(24): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2010.24.001Aiming at the state of highway management system in defect of real-time management of vehicles, this paper presents a novel algorithm to measure vehicle speed and location based on Radio Frequency Identification(RFID). By constructing moving vehicle model, spectral estimation is used to measure vehicle Doppler shifter and New-Town iteration method is used to solve the nonlinear characteristic of models in order to obtain the vehicle real-time speed and relative location. Simulation experimental result shows that the method for vehicle speed measurement and location can achieve high precision with little operation and simple maneuverability.
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Computer Engineering. 2010, 36(24): 4-5. https://doi.org/10.3969/j.issn.1000-3428.2010.24.002
A Web client is constructed based on Ajax and Observer design pattern to solve the problem of poor real-time and the lower rate of code reuse for existing monitoring system. It uses the Ajax to solve the real-time graphical display problem, and combines with observer design pattern. The rate of code reuse is increased, and the coupling between modules is reduced. Demonstration system is used to validate that the proposed method is feasible.
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Computer Engineering. 2010, 36(24): 6-8. https://doi.org/10.3969/j.issn.1000-3428.2010.24.003Image object segmentation method in accord with human vision perception, which consists of double-scale region segmentation and object extraction based on object model, is proposed in this paper. An image is smoothed by nolinear scale operator in coarse-scale, color quantization and perceptual color clustering are exploited to form the initial segmented regions. The initial regions are merged based on the region distance in the original finest-scale. Object model is used to implement image object extraction. Experimental results demonstrate that the proposed algorithm gets better image object segmentation with favorable consistency to human vision perception.
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Computer Engineering. 2010, 36(24): 9-11. https://doi.org/10.3969/j.issn.1000-3428.2010.24.004This paper proposes a fine-grained identification method of P2P-TV traffic based on channel signatures. It mines the channel signatures of popular P2P-TV applications through statistical analysis on their pure traffics. Channel signature matching is used to realize fine-grained identification of the application and channel of the traffic on a particular(IP, Port). Experimental results on PPStream, QQLive and UUSee prove that the method proposed is effective and accurate.
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Computer Engineering. 2010, 36(24): 12-14. https://doi.org/10.3969/j.issn.1000-3428.2010.24.005All-to-all communication in parallel algorithm is similar to transposing a square matrix. The Latin-square plays an important role as commutator in the process. This paper proposes an efficiently realization of short-message all-to-all communication algorithm based on Latin Square, and constructs a model analysis on this maximum message-volume, which is prior to the direct algorithm. Some tests verify this algorithm and model without considering the detail of network topology.
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Computer Engineering. 2010, 36(24): 15-17. https://doi.org/10.3969/j.issn.1000-3428.2010.24.006
Because of the nonlinear coupling relationship among process parameters, it is difficult for condition recognition of production process. A new criterion of kernel mapping is proposed, and the gradient optimum algorithm is used to select kernel parameter. Kernel Fisher discriminant analysis is applied to reduce dimension for realizing the multi-classification in the visual plane with layer by layer analysis method. The judgment on the current state can be realized. The Tennessee Eastman(TE) process data are used for model validation, the proposed method has more satisfactory performance on condition diagnosis, compared with kernel principal component analysis.
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Computer Engineering. 2010, 36(24): 18-20. https://doi.org/10.3969/j.issn.1000-3428.2010.24.007
On the basis of studying the theory of dynamic Virtual Enterprise(VE) based on Web Service architecture, this paper proposes a new model of cooperative partner selection for dynamic VE with extension QoS constraint in the large extended, it extends the traditional QoS, monitores and processes the enterprise extension QoS in a real-time sense by using QoS monitoring system, gives partner selection process under the model, and some key issues for the implementation of partner selection are analyzed. Some evaluations of the model performance is given, experimental result shows the rationality and feasibility of the model.
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Computer Engineering. 2010, 36(24): 21-23. https://doi.org/10.3969/j.issn.1000-3428.2010.24.008
A general model of wireless multiple video transmission schedule is proposed to achieve real-time monitoring of multiple scenarios. The model includes the communication setup method between the remote device and monitoring center in the beginning of transmission, the multiple video streams transmission schedule model based on the connection state, and the encrypting control method of the video stream. The model is adapted to any kind of IP network. It is applied in wireless video transmission system based on CDMA1x network, and good application effect is achieved.
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Computer Engineering. 2010, 36(24): 24-26. https://doi.org/10.3969/j.issn.1000-3428.2010.24.009According to the characteristics of life services, a model of life-oriented vertical search engine is proposed. The model describes specific algorithms and implementations of four functional modules, which include information collection, information extraction, index instruction and information retrieval. Practical application shows that the model search works well. The interfaces of HTML and WML are used to support the search request. It successfully supports search services for catering, entertainment and yellow pages information, covering nearly 40 Chinese cities.
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Computer Engineering. 2010, 36(24): 27-29. https://doi.org/10.3969/j.issn.1000-3428.2010.24.010In order to meet the requirements for user to access cultural information in a wide range, accurately, and quickly, design of digital museum objects information retrieval system is given. During the design process, some technologies are used, such as multi-threading, the information and then filtering, re-classification of information technology. The information acquisition, information analysis, information classification technology are improved. To solve the current number of limitations of the museum, there is the issue of information sources, while improving the accuracy of information, making a clear cultural information classification to achieve a fast retrieval of information objects.
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Computer Engineering. 2010, 36(24): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2010.24.011Based on the analysis of the loss of NTFS security attributes during data transfers to non-NTFS file systems or over network, this paper proposes a security attributes preservation scheme for lossless data transfer in Windows. Compared with traditional file copy and Windows NTBackup, the scheme preserves the original security attributes of the files transmitted and provides strong protection for data transmission.
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Computer Engineering. 2010, 36(24): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2010.24.012In SOA, there are several decentralized orchestration engines and their purpose is decomposing a BPEL process to several software agents. As these process distribution methods break a BPEL process to its building activities and encapsulate each activity in one agent, it results in producing a lot of agents. This paper proposes an Intelligent Process Distribution(IPD) approach based on process mining. The recommended IPD approach can improve three aspects of system quality: the amelioration of business process adaptability with run-time environment, choosing the best agent granularity based on detecting most relevant activities and encapsulating them in agents and decreasing of resource usage due to reduced and improved number of produced agents and messages.
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Computer Engineering. 2010, 36(24): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2010.24.013As the majority updating algorithms for association rules have the same shortcomings which only take account of the minimum support and data increase, without the minimum confidence and data decrease. This paper proposes a new updating algorithm for dynamic database which can avoid some shortcomings of the above. It can effectively mine some interested knowledge and save a large amount of mining time. Experimental result shows that the proposed approach is feasible.
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Computer Engineering. 2010, 36(24): 39-41. https://doi.org/10.3969/j.issn.1000-3428.2010.24.014This paper proposes a synthesized approach of similarity computation. It uses the Hirst-St-Onge semantic relativity algorithms to determine whether there is correlation among different domain ontologies. It takes account of the name, attributes, instances, relations of concepts and compares in many ways if it is relevant. A comprehensive similarity measuring method based on the MD3 model is proposed. It tests the method with two group data and then compares the results. Experimental results show that the approach is better than the MD3 model in recall rate and precision rate.
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Computer Engineering. 2010, 36(24): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2010.24.015
Pre-FUFP algorithm updates the frequent pattern tree effectively based on the concept of pre-large items. But when there are pre-large items becoming frequent items, the algorithm need check which transactions in the original database contains the pre-large items. In this paper, an index table of pre-large items to their corresponding original transactions is proposed to find out the transactions need to be processed and fasten the process of FUFP-tree modification. The frequent patterns by using compact FP-Tree and matrix based algorithm are worked out. Experimental result shows the algorithm outperforms the pre-FUFP algorithm.
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Computer Engineering. 2010, 36(24): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2010.24.016By analysis of Web user access sequence, it can find the factors of user’s hobbies, interests, habits etc.，and provides the necessary support of information for the upgrade and amendment of Web sites. This article proposes a method of data mining by analysis of the user access sequence. It can reduce the number of Web pages of the session sequence and compress the size of frequent traversal sequence by taking the duration time of Web page as a parameter. Experimental results show the algorithm can reduce the cost of mining and provide a useful reference for mining of Web users’ commercial data.
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Computer Engineering. 2010, 36(24): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2010.24.017Based on the analysis of the concrete semantics of programs, this paper proposes a method to detect the information privacy. It establishes corresponding relation between concrete semantics and abstract semantics, then establishes abstract semantics according to the properties of the programs to be checked, and meanwhile adopts bound methods to optimize detecting efficiency on the basis of abstraction. By this method, the complexity of program detecting is reduced, and the efficiency is raised and accuracy of detection is improved.
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Computer Engineering. 2010, 36(24): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2010.24.018
The inconsistency of interactive behavior’s sequence before and after component evolution will cause system behavior deviates from its goal. Interactive behavior between components is described based on Process Algebra(PA) and interactive behavior’s consistency is defined. The restriction which interactive behavior’s consistency will fulfill is epurated, and an approach to ensure consistency of interactive behavior is presented. An example is presented to illustrate the feasibility and validity of the approach.
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Computer Engineering. 2010, 36(24): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2010.24.019
The consistency verification and removal of redundancy behavior of composite component is an important issue in the field of Component Based Software Development(CBSD). The theory of interface automata is analyzed, and a more visualized presentation method of illegal state is presented by viewing composed component as a cycle process of initial state to itself. With scenario based requirement specification can always be modeled as sequence of events, digraph is used to model composed interface automata to give an algorithm of consistency verification. With the results of consistency checking, a method to remove redundancy behavior is also discussed.
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Computer Engineering. 2010, 36(24): 57-58. https://doi.org/10.3969/j.issn.1000-3428.2010.24.020This paper analyzes the load characteristics of storage devices, and proposes the expansion model for load. An object distribute module is discussed, real-time load info are collected for an object distribution algorithm, which make the objects distribute in a reasonable way, and dispatch I/O capabilities effectively among storage nodes. Simulation results show that the algorithm enables the loads to distribute balanced, and reduce the emergence of load imbalance effectively.
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Computer Engineering. 2010, 36(24): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2010.24.021
Kazak as one of the minority languages and characters being universally applied or used in Xinjiang, frequency statistic of word in Kazak natural language treatment becomes the problem to be solved urgently. This paper introduces the relation of Zapf in Kazak word segmentation, which is based on frequency statistic of the word. Through the system, continuous Kazak character bunch input can be segmented, and then the cut apartment word bunch output can be gotten. The cut apartment word bunch usually is two Kazak word bunch, and dictionary can be gotten. The dictionary stores Kazak word and the frequency that the word appears in these disposal test that combines proceeding Kazak covariance of article experiment. Experimental result expresses the relation of frequency of the Kazak word, and the resulting Kazak word frequency distribution accords with power-law of Zapf.
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Computer Engineering. 2010, 36(24): 62-63. https://doi.org/10.3969/j.issn.1000-3428.2010.24.022
Aiming at the incompleteness of interval-valued partial ordering relation which causes the problem of information loss in interval-valued information system which does not include decision attribute, this paper proposes a new interval-valued ordering relation based on interval-valued fuzzy number, then uses it to construct interval ordered information system, and analyzes its related monotonicity and included of upper and lower approximation. Furthermore, it presents an algorithm for attribute reduction based on indiscernibility function. Experimental result illustrates the algorithm is simple and effective.
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Computer Engineering. 2010, 36(24): 64-67. https://doi.org/10.3969/j.issn.1000-3428.2010.24.023From the view of rule base, a batch incremental algorithm for rule induction is presented in this paper. An equivalence class table is built for all new objects. Original rule base is efficiently matched with the equivalence class table. The rule base is updated for the new objects based on the different match types. The algorithm can deal with both complete and incomplete data and accomplish the rule update through only accessing rule base twice. Theoretical analysis and comparison experimental results on UCI datasets demonstrate that the algorithm outperforms traditional algorithms.
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Computer Engineering. 2010, 36(24): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2010.24.024Based on COSMIC-FFP and object-oriented method requirements model, the mapping rules between COSMIC-FFP and object-oriented method are summarized. Functional reuse is produced from the users’ perspective of function. And potential reuse through three kinds of generalization relationships in the object-oriented method requirements model is analyzed. According to use case models, a set of formulas are given to count functional requirements. Synchronously, an indicator is produced in order to indicate the proportion of the reused functional requirements and the total amount of functional requirements delivered. A case study is introduced to illustrate the measurement process of functional reuse for object-oriented systems.
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Computer Engineering. 2010, 36(24): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2010.24.025Based on symbolic operation, a novel approach is proposed to recognize and reduce Induction Variables(IV). It replaces all l-values in assignments by the original variables which can represent the iteration and dependence relationships among them, and constructs variable dependence digraphs to recognize IV. It establishes recursive equation sets to solve the problems based on symbolic operations, and gets their independent expressions composed of iteration number. Experimental results show that the method fits with different kinds of IV and overcomes the shortages of current methods.
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Computer Engineering. 2010, 36(24): 74-75. https://doi.org/10.3969/j.issn.1000-3428.2010.24.026
The high performance of Solid State Disk(SSD) has failed to be improved in the existing database systems. Aiming at this problem, a new connection method is proposed in this paper. The algorithm is optimized Flash database connection on the column files. Using the small size of column storage and the advantages of SSD high-speed random read, the algorithm overcomes the mismatch with the flash memory. Experimental results show that compared with the original algorithm, the query time of the new algorithm is less under the conditions of different query rate and different memory.
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Computer Engineering. 2010, 36(24): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2010.24.027Dynamic spectrum allocation provides a promising way out of the underutilization of many licensed frequency bands. However original graph-coloring algorithm is thoughtless for the cognitive user’s demand, which results in excessive allocation of resource to users with less demand and wastes spectrum resource. To solve the problem, a demand-based spectrum allocation algorithm is proposed, to match between channel and user’s demand. The performance simulation demonstrates that compared with the original algorithm, the proposed algorithm can better satisfy demand in the network.
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Computer Engineering. 2010, 36(24): 79-80. https://doi.org/10.3969/j.issn.1000-3428.2010.24.028
In order to solve the problem of network congestion, this paper proposes a network congestion control algorithm based on Tabu Search (TS) genetic optimization named TSGA, which combines TS and Genetic Algorithm(GA). An optimization mathematical model on multiple constrained QoS routing with the objectives of network resource consumption minimization and load distribution balance is presented. Simulation experimental results prove that the algorithm can realize network congestion control, and improve network performance effectively.
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Computer Engineering. 2010, 36(24): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2010.24.029According to the characteristic of Ad hoc On-demand Distance Vector(AODV) protocol which is relatively stable on the running time, a running time optimization method of AODV is proposed. The method exchanges the information between neighbor nodes and selects the optimal route to implement the routing optimization by the three link state values of route hop counts, battery power of nodes and RF signal strength. Simulation results prove that the improved routing protocol can increase packet delivery ratio and reduce average end-to-end delay.
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Computer Engineering. 2010, 36(24): 84-86. https://doi.org/10.3969/j.issn.1000-3428.2010.24.030Aiming at the problems of colored noise interruption and multi-spectral peak signals judgment in signal detection, this paper proposes a pre-processing algorithm for signal detection based on morphology, which treats the spectrum as one-dimensional gray-scale image. With regard to character of short wave channel and signal spectrum, it whitens colored noise by employing Top-Hat transform, and enhances signals by applying closing operation. Simulation experimental results show that colored noise can be suppressed, and weak signals and multi-spectral peak signals are reliably detected in complicated short wave channel environment.
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Computer Engineering. 2010, 36(24): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2010.24.031This paper proposes a Markov chain model for performance analysis and evaluation of S-MAC protocol. The model uses the moment generating function and signal flow graph to analyze MAC access delay of S-MAC protocol. M/G/1/K queuing model is applied for performance analysis of the protocol in non-saturation condition. Mathematical analysis and simulation experimental results demonstrate the model can describe the access way of S-MAC protocol well.
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Computer Engineering. 2010, 36(24): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2010.24.032
This paper proposes a Wireless Sensor Network(WSN) node positioning algorithm based on studying Received Signal Strength Indicator(RSSI) and Support Vector Classification(SVC). It considers node RSSI value as a multi-classification problem of characteristic quantity, converts RSSI into node position directly by SVC which has good generalization ability to realize symbolic positioning and physical positioning, and achieves a higher positioning accuracy. Experimental results show that the symbolic positioning effect of the algorithm is good, when the anchor node density is 20%, 98.19% of the nodes can get correct position.
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Computer Engineering. 2010, 36(24): 93-95. https://doi.org/10.3969/j.issn.1000-3428.2010.24.033Based on Serving GPRS Support Node(SGSN) and Gateway GPRS Support Node(GGSN), this paper implements a communication mechanism between mobile terminal and remote computer with analyzing the 4-layer construction of J2ME and the relationship between different virtual machines, configuration layers and profiles. It implements the communication mechanism with the functions such as receiving information, sending information and controlling at mobile terminal with J2ME, and initialization, sending and receiving data, command parsing and execution at remote terminal with VB 6.0. Experimental results indicate that the mechanism has good communication ability and it can satisfy the communication requirements of many kinds of remote control system.
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Computer Engineering. 2010, 36(24): 96-98. https://doi.org/10.3969/j.issn.1000-3428.2010.24.034
Previous dynamic cluster configuration methods are based on the specific physical experimental models without the description of mathematical models. Aiming at the problem, this paper proposes a prediction-based dynamic clusters configuration strategy, which uses least mean square to predict the situation of service requests in the future time according to the network historical information of service requests. On the basis of the load requests and the clusters processing power, it decides the servers’ scale and dynamically adjusts the opening and shutdown of the computers in the server cluster. Experimental result verifies the feasibility and superiority of the schedule strategy.
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Computer Engineering. 2010, 36(24): 99-101. https://doi.org/10.3969/j.issn.1000-3428.2010.24.035Chaotic sequence with its good correlation performance being sensitive to initial condition and hard to decrypt is used as spread-spectrum code in Direct Sequence Code Division Multiple Access(DS/CDMA) system. In order to improve the security of DS/CDMA system and decrease the multiple access interference, the traditional optimized selection algorithm of chaotic sequence is improved. By studying the chaotic cross-correlation optimization, a new cross-correlation optimized selection algorithm of chaotic spread-spectrum sequence is proposed, and the performance of the optimized sequence is simulated and compared. Experimental results show that the algorithm has better correlation performance, larger capacity and lower multiple access interference.
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Computer Engineering. 2010, 36(24): 102-103. https://doi.org/10.3969/j.issn.1000-3428.2010.24.036
The controller design for networked controller with bandwidth constraints is studied in this paper. The scheduling strategy based on stochastic communication logic is presented using Poisson process with time-dependent intensity. Then the limit updates are obtained. According to its Markov jump linear characteristic, the controller is co-designed based on update time. Simulation results show that the times of state update are reduced, the influence of bandwidth on control performance is decreased, and the dynamic performance of the system is improved by means of introducing stochastic communication logic.
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Computer Engineering. 2010, 36(24): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2010.24.037The route of HF networks is influenced by many factors, and it is very difficult to select the best path. Aiming at these problems, a dynamic source route protocol appropriate for HF networks is designed based on Analytic Hierarchy Process(AHP). The influence of the link quality, path length, node load and survival time on the HF route path selection is analyzed. A mathematical model of AHP is constructed which makes the comparative matrices and calculates the weight vector based on the factors of path selection. HF route protocol is designed and an example is concluded to analyze the route discovery and update.
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Computer Engineering. 2010, 36(24): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2010.24.038
Network coding is inherent vulnerable to the data pollution attacks. To address this problem, it discusses two random linear network coding pollution data detection schemes, one is based on homomorphic hash function which deduces the general formation and proves its correctness. The other is linear space signature. It comparatively analyzes their computational cost and payload efficiency under different data block size conditions, and proposes a new combinatory detection scheme for this problem.
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Computer Engineering. 2010, 36(24): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2010.24.039This paper analyzes a group signature scheme that it has the property of member deletion, points out that signature open algorithm and validated algorithm are all invalid, and it has redundant data because of signature parameter setting incorrectly. It improves group signature scheme on the basis of it. By attaching the signature public key to signature parameters, it resolves the problem of the identity revelation algorithm invalidity. By modifying group centre to trusted centre and removing the group manager entity, it resolves the problem of the group centre excessive power to improve the overall effectiveness of improved scheme.
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Computer Engineering. 2010, 36(24): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2010.24.040The probability theory and social network theory are applied to trust delivering and multiple trust route modeling. Aiming at the actual business network characteristics of C2C transaction platform, this paper presents a C2C trust evaluation model based on social network and reputation. It introduces similarity computation to establish cluster and cluster relationship to solve the common problems in C2C transaction network such as division of labor, sparse and clustering. Analysis results of TAOBAO transaction platform data show that this model has a very good improvement and complement to the existing reputation system of TAOBAO, and it simulates the interpersonal relationships of trust and recommendation in real life.
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Computer Engineering. 2010, 36(24): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2010.24.041Traditional research on trust model is based on environment with history cooperative information, it can hardly meet the needs of dynamic evolution of the cooperative environment. Aiming at situations which are without direct history information, indirect trust model based on the third-party organization is analyzed by referring to the third-party management method in modern E-commerce, and a DRI(Direct, Recommending and Indirect) trust model is proposed by combining with Bayesian trust model. Experimental result by comparing with traditional trust model shows that the cooperation based on DRI trust model can effectively improve the reliability of cooperative object selection, and improve the average successful rates of cooperation.
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Computer Engineering. 2010, 36(24): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2010.24.042In view of drawbacks of current permission systems and role authorization, this paper designs IPC_URBAC model, adds user direct authorization mechanism based on user inheritance constraint and user role assignment mechanism based on priority constraint, puts forward authorization conflict resolution strategy based on individual and priority, and gives algorithms for solving the set of privileges belonged to a user and a role. It uses IPC_URBAC model, designs binary authorization mask to resolve setting problem of complex permission, and separates permission controls from concrete business by using Web service to complete the fine-grained permissions check, realizes a flexible authorization system having nothing to do with business.
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Computer Engineering. 2010, 36(24): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2010.24.043
Aiming at the coding characteristic of GIF image, this paper presents an image selection encryption algorithm under degradation and confidentiality modes. Intra-set shuffle index method is used to control image degradation visibility for degradation model. It encrypts only fractal of the image, the whole image is protected for confidentiality model. Analysis results show that this algorithm can meet the requirements of security, format-compliance, and it also can constant compression-ratio.
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Computer Engineering. 2010, 36(24): 125-126. https://doi.org/10.3969/j.issn.1000-3428.2010.24.044
According to the changes of the historgrams of the first digital distribution and the individual DCT coefficients caused by the steganography algorithm, such as Outguess, F5, Steghide, this paper proposes a new detection algorithm for the JPEG Image. It extracts 144 features by using the first digital distribution and the histograms of individual DCT coefficients, and uses Fisher classifier for recognition. Experimental results show that the algorithm has high detection rate and chronic adaptability.
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Computer Engineering. 2010, 36(24): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2010.24.045
In Ad hoc networks, group key management is one of the most important secure problems. This paper proposes a hierarchical group key management scheme adapted to large groups according to network characteristics. The scheme puts STR hierarchical tree structure into distributed subgroup management model effectively, and combines layer-based key management with cycle-based key management, in order to reduce the communication and computation cost greatly. Experimental result shows that this scheme is of good attribute in expansibility and lange Ad hoc networks.
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Computer Engineering. 2010, 36(24): 130-131. https://doi.org/10.3969/j.issn.1000-3428.2010.24.046
This paper analyzes a certificateless verifiably encrypted signature scheme which is proposed by Zhou Min et al and points out that their scheme can’t resist the public key replacement attack, it does not satisfy two basic security properties of verifiably encrypted signature: unforgeab- ility and extractability. Moreover, their scheme has key escrow issue, so it has not the advantages of certificateless public key cryptosystem.
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Computer Engineering. 2010, 36(24): 132-133. https://doi.org/10.3969/j.issn.1000-3428.2010.24.047
In the proxy signature schemes from pairings, the pairing operations are the most time-consuming. In order to reduce times of the pairing operations, this paper proposes a new proxy signature from bilinear pairings. The security of the scheme depends on the hardness assumption of discrete logarithm problem and the computation Diffie-Hellman problem. Its security is analyzed and the result shows that this scheme is secure and effective, it can effectively resist the strong forgery attacks and satisfy the security properties of strong proxy signature. Compared with other schemes, the new scheme has better computational efficiency.
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Computer Engineering. 2010, 36(24): 134-135. https://doi.org/10.3969/j.issn.1000-3428.2010.24.048
A trust model based on social rules and the topology characteristic of unstructured P2P network is proposed in this paper. A distributed storage mechanism of evaluation information is designed. The calculating, updating and searching methods of reputation information are given. The computation complexity and communication cost of this algorithm are low. Experimental results show that the proposed trust mechanism can resist the attack of malicious peers effectively.
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Computer Engineering. 2010, 36(24): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2010.24.049For fuzzy-uncertainty with class overlap and rough-uncertainty with lack of features, this paper proposes a fuzzy-rough nearest neighbor clustering classification algorithm based on Expectation-Maximization(EM), named EM-FRNN. Through the experments with UCI emergency water pollution cases database, compared with the classic algorithms, such as KNN, FKNN, FRNN, EM-FRNN algorithm improves classification precise and reduces computation.
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Computer Engineering. 2010, 36(24): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2010.24.050
A partition reconstruction method for disparity image based on homogeneous RBF network is presented. Disparity image is divided into some regions by reconcilable threshold and edge detection. Reconstruction based on RBF neural network is carried out in every region. All regions are combined and reconstruction result comes into being. When reconstruction based on RBF is executed in different region, data which have different resolving power are used in training according to structure of different region. Experimental results show that good reconstruction can be attained by the using method proposed.
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Computer Engineering. 2010, 36(24): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2010.24.051For the target-tracking using active sensor and passive sensor with asynchronous sampling frequency, a new decoupled algorithm is proposed. On the sampling time without distance measurement, the tracking filter is processed by making up virtual measurement point. Because all the angle measurement information is effectively utilized by the algorithm, the performance of tracking filter is elevated. Simulation results show that the algorithm has high tracking precision and its computational cost is smaller.
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Computer Engineering. 2010, 36(24): 145-146. https://doi.org/10.3969/j.issn.1000-3428.2010.24.052
To efficiently resolve action classification problem, a classification algorithm based on Action Energy Image(AEI) is proposed. The high dimensional feature space is reduced to lower dimensional space with (2D)2PCA. The nearest-neighbor classifier is adopted to distinguish different actions. It need not extract the period of the video, which is indispensable in some other methods. Experimental results show that the algorithm achieves higher classification accuracy with less running time and less memory space.
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Computer Engineering. 2010, 36(24): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2010.24.053
This paper proposes an advanced co-evolutionary model fitting algorithm. It optimizes the process in the course of solving the symbolic regression, especially to the shortcomings of traditional Genetic Algorithm(GA). It abstracts the modeling and optimization into a variety of inter-group co-evolution, associating these populations through exchange of fitness value, while extending the intelligent algorithm both in spatial and temporal scope when optimizing the parameters modeling. For the various groups with different gene expression, they have their nature self-contained in solving certain problems. It is more conducive to take advantages of the intelligent algorithms(GA, Genetic Programming(GP)). Compared with the traditional algorithm, the co-evolutionary model fitting algorithm shows a significant improvement in stability and convergence rate.
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Computer Engineering. 2010, 36(24): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2010.24.054
For the dynamic environment problem, this paper presents a self-learning function of the Symmetry Particle Swarm Optimization(SymPSO). The algorithm proposes to detect changes of the environment by using a static virtual particle swarm, and based on the thought of symmetric particles, without increasing the computational complexity, generates multiple symmetric virtual population. It can significantly expand the ability of population. To ensure the algorithm to escape from local optimum as quickly as possible, this paper proposes wide-area learning strategies to enhance self-learning ability of particles. Simulation comparative tests based on DF1 environment show that SymPSO algorithm can track the optimal value changes and escape from local optimum quickly, indicating the effectiveness of the algorithm.
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Computer Engineering. 2010, 36(24): 153-155. https://doi.org/10.3969/j.issn.1000-3428.2010.24.055Aiming at the problem of clustering algorithm long time in processing high-dimensional mass data, a sampling-based multi-modal distribution clustering optimization algorithm is proposed, which greatly reduces the clustering time. In iterative correction procession, the algorithm randomly extracts small samples from whole datasets. The optimal configuration parameter of algorithm is found by a large number of experiments. Experimental result shows that the optimization algorithm fulfills 88% of the clustering accuracy with 11.8% of the clustering time, and provides the optimal clustering scheme for the application environment of high time cost.
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Computer Engineering. 2010, 36(24): 156-157. https://doi.org/10.3969/j.issn.1000-3428.2010.24.056To solve the contradictory between convergence speed and precocity and stagnation in ant colony algorithm, this paper references the ability of the self-regulation mechanism to maintain the population diversity on immune algorithm. The immune-ant colony algorithm is presented. According to micro-diversity, macro-diversity and the concentration of arc, this algroithm dynamically adjusts the selection probabilities of the paths and the trail information updating. Simulation experimental results on symmetric and asymmetric TSP show that the presented algorithm has much better intensification and diversification than that of classical ant colony algorithm and is more suitable for solving large scale TSP.
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Computer Engineering. 2010, 36(24): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2010.24.057
In order to give more help to athletes’ exercise, a human motion simulation system based on binocular stereo vision is established. Using a mark-less motion capture algorithm, the pixel coordinates of human skeletons in the image are captured. According to binocular stereo vision theory, the world coordinates of human skeletons are computed and the 3-D human model is constructed. The human model is optimized by computing the energy function. The human motion is simulated and the parameters of human motion are figured out. Experimental results demonstrate that the simulation system can do well in motion capture and simulation of human motion.
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Computer Engineering. 2010, 36(24): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2010.24.058
For problem of imbalanced data learning, a gradually learning classification algorithm is proposed. This classification algorithm gradually adds the synthetic minority class examples according to attribute value-range distribution, and removes timely the synthetic examples which the stage classifier misclassifies. As the data achieves the desired degree of balance, the method uses raw data and synthetic data training learning algorithm, and gets the final classifier. Experimental results show that the gradually learning algorithm is better than C4.5, and better than SMOTEBoost and DataBoost-IM on most data sets.
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Computer Engineering. 2010, 36(24): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2010.24.059To solve the schedule optimization problem of city bus drivers, this paper proposes a solution of schedule by using immune optimization. The mathematical model of schedule problem of bus drivers is expounded, a frame of immune optimization algorithm is given, proportional cloning operator and neighborhood mutation operator with real-number encoding are designed, and simulation experiments are done to validate algorithm. Experimental result shows that optimization algorithm given in this paper can solve the schedule problem of bus drivers, and has the advantage of good application value.
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Computer Engineering. 2010, 36(24): 167-168. https://doi.org/10.3969/j.issn.1000-3428.2010.24.060
It is an important task for knowledge-based systems to select and evaluate the attributes as well as a critical factor affecting systems’ performance. Using the genetic operator of the searching approach and correlation analysis, which characterizes Genetic Algorithm(GA), as the evaluation mechanism, this paper presents a new method to select the optimal subset of attributes for a given case library. Experimental results show that the proposed method can identify the most related subset to classify and predict, while reducing the representation space of the attributes whereas hardly decreasing the classification precision.
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Computer Engineering. 2010, 36(24): 169-171. https://doi.org/10.3969/j.issn.1000-3428.2010.24.061Aiming at the problem of Artificial Fish Swarm Algorithm(AFSA), such as long running time or being in local extremum, caused by inappropriate parameters setting, this paper uses the improved Global edition Artificial Fish Swarm Algorithm(GAFSA), optimizes three benchmark functions to conduct simulation studies with different parameters matching, and analyzes the change law of the optimization performances and the convergence speed of the artificial fish swarm algorithm under the influence of the main parameters, and gives the appropriate ranges of parameter setting. Experimental results show that reasonable parameter settings make algorithm get better optimization performances and quickly convergence to the global better solution.
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Computer Engineering. 2010, 36(24): 172-174. https://doi.org/10.3969/j.issn.1000-3428.2010.24.062As the amateur singer’s timbre is not converted in the process of voice imitation from amateur singer to the professional singer, this paper presents a singing voice Morphing algorithm based on Gaussian Mixture Model(GMM). The spectrum parameters are extracted from the source and the target singing voices are modeled by GMM respectively, and the singing’s timbre is converted by mixing their model parameters. Experiments demonstrate that the accuracy of ABX test can be up to 100% in the case of k=0 or 1, and the accuracy still be higher than 62.5% in the case of 0
