Computer Science

Trust and Reputation Mechanism in Multi-Agent System

HE Li-jian,HUANG Hou-kuan

Computer Science. 2011, 38 (4): 1-8.

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Trust plays an important role in the interaction of human society, and is focused on in many related research domains. Trust is also introduced to open multi-agent system to help agent choose interaction partner. Reputation can act as one of sources of trust information, which is closely related to trust. Reputation system is a mechanism to evaluate trust in MAS. Research on trust in MAS should take on responsibility of finding the general law of trust among computational entities. The content, rectuirements and applications of trust and reputation system were discussed in the paper.In terms of technology, there arc cognitive and numerical opinions in trust representation, and centralized, distributed and mixed frameworks were adopted by the reputation system. The statistics, probability, belief theory and fuzzy reasioning methods were used to aggregate reputation information. At last, some problems were put forward to study further in the future, which cover group reputation, inaccurate report, lacking of information and interoperation between heterogeneous reputation systems.

Study on Context-aware Technologies for Internet of Things

TONG En-dong,SHEN Qiang,LEI Jun,LIU Yu,TANG Hui

Computer Science. 2011, 38 (4): 9-14.

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Unlike Internet which connects people all over the world,Internet of Things(IoT) is a net of things which connects the marked and intelligent entities by using various of wireless technologies.As technologies of information industry and wireless communication have developed,computing resources surround people.Context-aware systems emerge at this time.Context-aware systems deal with the pervasive contextual information captured by numbers of sensors and then provide users with the right services.IoT features its requirement of dealing with mass data.Due to these characteristics,the current technologies are nolonger working well.Inthis paper,we did a survey on the context-aware systems.Wemade definitions of context and context-aware,introduced the development and applications of context-aware technology,and then considering of IoT,we approached the flow or progress of context-aware system,including context collecting,context modeling and intelligent information processing.Finally,we analyzed the cruuenct context-aware architectures and made some improvements.

Overview of Data Extraction, Transformation and Loading

XU Jun-gang,PEI Ying

Computer Science. 2011, 38 (4): 15-20.

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Data extraction, transformation and loading arc crucial steps of data warehousing, which influences data qualily of data warehouse intensively. With the development of informationization, ETL has already become one of most popular research fields,but till now,ETL theory and technology are still not mature. As to the problems and factors appeared in ETL research, many research methods and achievements were listed according to the main problems existed in each ETL phase. Finally, several future research trends of ETL and some proposals for the future research work were summarized and presented respectively.

Review of Point Cloud Segmentation and Application

LIU Jin,WU Zhong-ke,ZHOU Ming-quan

Computer Science. 2011, 38 (4): 21-24.

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A summary of the definition, classification and application of point cloud segmentation was presented, several kinds of typical point cloud segmentation algorithm were compared, analyzed and evaluated, such as edge-detection method, surface-growing method, scan-line method, clustering methods, graph partitioning methods, etc. The characterstics and application environments of each method were presented. The main problems in point cloud segmentation methods were pointed out, and the description and evaluation of point cloud segmentation in related fields were conducted. At last, problems and prospect of the techniques were also discussed.

Research Advance of Facial Expression Recognition

JIANG Bin,JIA Ke-bin,YANG Guo-sheng

Computer Science. 2011, 38 (4): 25-31.

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In recent years, facial expression recognition has become a hot research direction in human computer interaction,machine learning,intelligent control and image processing. According to feature extraction and feature classification, recent developments of facial expression recognition were presented. From static images and image sequences, the methods of feature extraction can be divided into two categories. The former includes holistic methods and local methods, the later includes templatcbased methods, geometry-based methods and optical flow methods. In the classifier design, the main methods of feature classification can be categorized by Bayesian Network methods and Distance Metric methods. Finally, combining the latest productions and applications at home and abroad, the expectation of the development of facial expression recognition was given.

Research Survey of Cloud Computing

LI Qiao,ZHENG Xiao

Computer Science. 2011, 38 (4): 32-37.

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Cloud Computing is a new application model for decentralized computing which can provide reliable, customized and maximum number of users with minimum resource, and it is also a important way to carry out Cloud Computing theory research and practical application combining with other theory and good technictues. This paper summarized cloud computing concept, discussed cloud computing advantage and problem, compared different technology and got characteristic of cloud computing, analyzed the architecture of cloud computing, introduced different cloud computing service,presented a survey on service and architecture aspects of cloud computing, analyzed the relationship between service and architecture, summarized related research about relationship of service and architecture of cloud computing. This paper also presented a summary of the current art of the state of cloud computing, a discussion on the future researches topics and some crucial problems which should be solved pressingly.

Survey of Trust Management in Distributed Multi Trust Domain

ZHU Zhong,WU Guo-xin

Computer Science. 2011, 38 (4): 38-42.

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With the rapid development and extensive application of Internet technology, emergence of Internet based virtual community, such as P2P, Urid, wireless networks, multi-agent networks, wireless sensor networks, has caused the migration of reputation related concepts from the world of human interactions to the world of virtual interactions. In recent years, researchers have proposed various trust management models for virtual interactive world, such diversity of trust management model will bring multi trust domains in the different application environments. Some papers have proposed how to achieve trusted interactions between multi domain agents.The interrelated concepts and reasons of multi trust domain were summarized and presented. Several typical trust management systems of multi trust domain including their various methods were described in detail. The current problems and the challenges of this field for future research were presented.The research work indicates that the trusted interactions between multi domain agents create the biggest challenge in the trust management.

Survey on Multi Rate Adaptation in Wireless Networks

XU Zhuo-nong,WANG Jian-xin,HUANG Jia-wei

Computer Science. 2011, 38 (4): 43-47.

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In IEEE 802. 11/a/b/g Wireless Local Area Networks, the physical layers support multiple transmission rates. Since the wireless channel varies over time due to such factors as station mobility, time-varying interference, signal fading, and so on, it is very important for the transmitting station to assess channel conditions and accordingly adjust the rate in order to yield higher throughout Rate adjustment mechanism can be classified into open-loop schemes based on statistics information and closcloop schemes based on the RTS/CTS information feedback. We summaried the performance of the rate adjustment schemes,analyzed the key issues which include initial rate,packet loss distinction and adjustment strategies, and pointed out the present problems and future research interests.

Advances on Digital Rights Usage Control in Digital Rights Management

ZHANG Zhi-yong,NIU Dan-mei

Computer Science. 2011, 38 (4): 48-54.

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Digital Rights Management(DRM) technology is crucial to a prosperous and meaningful development of digital contents industry, thereinw digital rights usage control mechanisms can guarantee that end users access to contents,transfer and share the corresponding rights by an authorized model. Based on an analysis of preventive and reactive DRM research roadmaps, a survey of research advances and progresses was made on Rights Expression Languages (REL)and usage control, rights delegation and transferring, trusted rights execution and secure terminal platform regarding a generic DRM system and Mobile DRM, as well as representative RELs and formalized usage control models were analyzed and compared. Finally, some open issues and challenges on digital rights usage control were addressed.

Modeling Method of Tree Graph Based on Mobile Server-Side

LIU Wei,LI Zhou-jun

Computer Science. 2011, 38 (4): 55-60.

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Mobile multimedia and mobile Internet arc the the important directions of mobile service development.However, it is the high cost with high data transmission rate of wireless multimedia communication service. Under the premise of no increasing the investment in hardware, the personalized service could be applied to mobile service not only reducing wireless multimedia communication cost but also without reducing quality of mobile service for users. It advanced a kind of model on tree graph which works on server-side. It integrated individual requirements of users in mobile terminal with recommended information resources on the Internet together in order to organize multicast push. The paper drew into the theory of interval valued fuzzy sets and explained the method of model on tree graph in theory, brought forward a series of correlative definitions and formulae on founding the model and designai an algorithm on founding and updating the node of the tree graph. Finally, it useed an implement of well-ordered to strictly prove the determinacy of the algorithm, and then, analyzed time complexity of the algorithm. On the theory, the algorithm is proved of the traits of determinacy, validity and low time complexity. It should be considered that the works is a useful attempt in the research fields.

Method for Generating Key Stream Based on Encoding

WEN Tao,ZHANG Yong,GUO Quan,LI Feng-kun

Computer Science. 2011, 38 (4): 64-64.

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The paper formulated the generating procedure of key stream of chaos in the term of information theory,presentd and proved that generating efficiency of key stream can be improved through sampling-and- encoding method to process real number sequence of chaos. And the paper made research on the relationship between the amount of encoding bits and pseudorandomness and generating efficiency. The amount of encoding bits effects pseudorandomness of binary sequence a little, and the standard device tion of each sample is 0. 0135 at most, specially, when 18, the standard deviations converge apparently. Generating efficiency keeps higher, when the amount of encoding bits falls into the interval of 6 through 15, and arrive to the highest point when 12. The paper compared the binary-field method and the proposed sampling-and- encoding method in terms of theoretic and experimental proof and showed that sampling-and- encoding method can reserve more pseudorandom information so that it can improve the generating efficiency of key stream. The sampling-and- encoding method is a beneficial tentative experience to enrich the generating ways of key stream.

On Incentive Strategies for Trust Recommendations in Wireless Ad Hoc Networks with Probability Game

SUN Yu-xing,ZHAO Yan-fei,LI Ya,XIE Li

Computer Science. 2011, 38 (4): 65-71.

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Trust recommended behaviors rely on the cooperation among nodes in wireless ad hoc network and trust system itself cannot provide trust evaluations for the behaviors. We proposed a repeated probability game to facilitate the study of the interaction process for trust-recommended behaviors between nodes. Based on the model, we analyzed the INFLUENCE of the four types of incentive strategics, namely TFT,GTFT,OT,GT to motivate the trust-recommended behavior between nodes, as well as the DIFFERENCE of the ectuilibrium boundary conditions of the four incentives strategics. Simulation results show that, in the high rate of sudden selfish behaviors, GTFT strategy keeps Efficient Recommendation Ratio at a higher level,motivates the cooperation of trust recommended behaviors and then helps the trust system to make timely and accurate trust evaluations in the case of collusion attacks.

Research on Access Control Technology on Mobile Ad-hoc Networks

XIONG Ting-gang,LU Zheng-ding,ZHANG Jia-hong

Computer Science. 2011, 38 (4): 72-75.

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Resources share and protection are one of key problems needed to solve on mobile ad-hoc networks (MANET).A dynamic paths quorum system on MANET was proposed by making use of the model of voronoi diagram and the idea of quorum system. The construction algorithm of dynamic paths quorum was designed. Based on the dynamic paths quorum system on MANET, a distributed access control mechanism was given and the protocols, such as node authentication, network resources authorization and rights management, were described in detail. Compared with traditional access control mechanism grounded on single node in MANET, the distributed access control mechanism grounded on more nodes, i. e. a quorum nodes, has higher availability and greater capability to withstand attack. It can improve the level of resources share and protection on MANET observably.

Improved Dynamic Spectrum Allocation Mechanism Based on Real-time Spectrum Demand and Offer Mapping

WANG Fan,ZHANG Jian-zhao,ZHAO Hang-sheng,YAO Fu-qiang,FENG Shao-dong

Computer Science. 2011, 38 (4): 76-79.

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The rapid development of modern wireless communication technology requires more and more spectrum which renders the transaction from static spectrum allocation to dynamic spectrum allocation. Aimed at the question that multiple networks access an coordinated spectrum access spectrum(CSAB) through a central spectrum broker, an improved dynamic spectrum allocation mechanism was proposed based on real-time spectrum demand and offer mapping (RT-DOM). As contrast with general sequential dynamic spectrum allocation(S-DSA) mechanism, the RT-DOM focuses on the spectrum requirement change between two consecutive dynamic periods, and maps the released spectrum (spectrum offer) and the new spectrum demand,in order to make less the spectrum handover than S-DSA And the simirlation results show that the spectrum handover reduces at least 75% while allocation gain reduces very little.

Model and Analysis of Peer-to-Peer Storage System Reliability Based on Stochastic Petri Net

LIU Zhi-ming,SHA Ji-chang,YANG Xiao-hua,WAN Ya-ping

Computer Science. 2011, 38 (4): 80-83.

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Reliability is one of the basic connotations of dependability, and it is also the key of P2P Storage Systems study. P2P storage system nodes are highly dynamic. That nodes are from online to offline frequently will lead difficulty to system reliability analysis. If increasing the number of copies because nodes are temporarily offline, it will cause system to unnecessary outage. The larger number of copies will increase system reliability, but it will also cause the system to increase the cost of consistency maintenance. And the fewer number of copies will result in a significant reduction in reliability of the system.To address the problem of the quantity of copy and system reliability, a reliability model of P2P storage system which revolved around relationships between the rectuirements of data reliability measurement and the number of copies was built by stochastic Petri nets(SPN) and used to analysis. It identified the purpose and basic principles of studying system reliability from theory and can help to optimize the system design on curly stage.

Method for Available Bandwidth Measuring and Analysis of IPv6 Network

QIU Quan-jie,WU Zhong-fu

Computer Science. 2011, 38 (4): 84-86.

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Based on the analysis of the measurement principle of IPv4 network bandwidth and with the combination of the next generation network protocol IPv6,we put forward a on}way and different length packet pair subtraction method for available bandwidth measuring of IPv6 network. An IPv6 network available bandwidth measuring prototype system was designed and programmed by using the flow label field of IPv6 messages to control the sequence path of tested messages. The test results show that the algorithm is feasible for IPv6 network with the measuring error less than 0. 1M. The measuring results arc realistic and better to reflect the real-time correlation of network available bandwidth and time delay, providing a useful means of network monitoring and performance measuring.

Research on SUPANET OAM-based Protection Switching

DOU Jun,CHEN Wen-jia

Computer Science. 2011, 38 (4): 87-92.

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Single-layer User-data switching Platform Architecture(SUPA) which is based on Ethernet oriented Physical Frame Timeslot Switching(EPFTS) is promoted as a Future Internet architecture. SUPA User-platform OAM mechanism was introduced to provide operations including connectivity diagnosis, trace diagnosis and fault recovery in SUPA networks ( SUPANET)domain. Based on SUPA Virtual Line Switching(VLS) services,the authors focused on research on SUPA OAM-based protection switching mechanisms. Finally, based on QVL(QoS Virtual Line) and SVL(Shared Virtual Line) services, OAM-based protection switching mechanisms for the User platform in SUPA networks were proved validity in simulation experiments,and the comparison of the simulation results shows that QVL-based protection switching is better than SVL-based protection switching in QoS provisioning capability.

In-Symbol Correlation Spectrum Sensing Method for OFDM Systems in Cognitive Radio

DUAN Peng,HE Ming-yi,XUE Min-biao,DANG Qun

Computer Science. 2011, 38 (4): 93-96.

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Based on characteristic of periodic sequence,a novel spectrum sensing method that takes the correlation calculation was proposed in OFDM systems.Firstly,divided the received sequence into two part,and took average calculation respective to reduce the noise variance in an OFDM symbol,then used the two sub-sequences to take the correlation calculation,the influence brought by time-vary channel could be reduced.And the expectation and variance of correlation value were analyzed,verifying the new method was of validity.The experiments showed that the new method outperforms the traditional method in time-vary channel,reduces the number of symbols involved in the calculation,and has the low calculation complexity.

Research on Detection Methods for Insidious Attack of Wireless Sensor Networks

WANG Liang-min,LI Fei,XIONG Shu-ming,ZHANG Jian-ming

Computer Science. 2011, 38 (4): 97-99.

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Insidious attack becomes more and more important to the security question of wireless sensor network with the developments of its hardware and software. A comprehensive survey on the detection methods for this attack was presented in this paper. Firstly, these methods were introduced in 3 classes: detection on attack behaviors, compromised nodes and replica nodes. Then it was pointed out that the detection assumption of pre-known attack behavior, outnumtiered benign nodes or absolutely secure sink or base station bottlenecks the application of these methods. Furthermore,the issues about attack detection in the mobile wireless sensor networks were introduced, and then the challenges and advantages about mobile nodes over the attack detection for wireless sensor network were discussed. Finally, the possitile developments of methods for detecting insidious attack were presented.

Study on Pareto-based Industrial WSN Multi-objective Optimization Routing Algorithm

WU Yi-zhi,QUAN Dong-ping,XU Hong-an,QI Jin-peng,DING Yong-sheng

Computer Science. 2011, 38 (4): 100-103.

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Industrial WSNs have various performance indicators such as real-time and reliability. In order to meet those performance rectuirements,multi-objective optimization may apply on routing algorithm design. This paper modified Collection Tree Protocol (CTP) and presented Pareto-based multi objective optimization routing protocol TCTP. In the quality evaluation of single hop link,TCTP adds a performance indicator of single hop transmit delay. Then a multi path routing strategy was established on routing topology by Pareto principle, also with multi path routes selection based on performance indicators of real-time and reliability. Finally a colored Petri net was adapted to formalize TCTP, which has been realized and verified by CPN Tools. Compared with CTP,TCTP surpasses on adaptability and flexibility on transmit path selection,and satisfies multi-objective data transmission requirements of real-time and reliability in industrial WSNs.

Encryption Scheme of Data Hiding in Digital Audio Based on Generalized Synchronization Theorem for Discrete Chaos

YIN Ping,MIN Le-quan

Computer Science. 2011, 38 (4): 104-106.

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A new chaos system was established based on the theorem of generalized synchronization and 3D-Lorenz system.The chaos sectuences generated via this system and Arnold' s cat map have better pseudo-random properties. A message encryption and hiding scheme was also established on the system and Arnold's cat map. The scheme is successful to encrypt and decrypt message. Ciphertexts are sensitive to the parameters and initial conditions of the chaos system. Numerical simulations show that our scheme is effective to be used in network communication. It shows that this scheme has good security.

RFID Positioning System Construction Method Based on Virtual Reference Tags

LI Jun-huai,SUN Zhuan-yi,WANG Yi-le,WANG Feng

Computer Science. 2011, 38 (4): 107-110.

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As current RFID positioning system can only provide a single location based servcie and low localization accuracy for interferring each other in an area where deploying a large number of RFID devices,the paper proposed a RFID positioning system construction method which is using classical signal propagation model to construct a virtual reference tags in position area,and then designed a mobile object positioning menthod based on virtual reference tags space. The experiment results show that the method may enhance positiong accuracy and overcome the interference problems caused by deploying a lot of reference tags and reader, positioning accuracy in the central region to reach 0.31m~1.65m,between the error in the external region between 1.48m~3.72m.

New Threshold Signature Scheme Based on Bilinear Pairings

LU Xin,WANG Zhi-jian,XU Feng

Computer Science. 2011, 38 (4): 111-114.

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To meet the new requirements drown by nowadays E-commerce for the signature schemes, a new threshold signature scheme was proposed from bilinear pairings based on improved short signature scheme, in which a single signing member can accomplish signature efficiently. The analysis shows that the scheme serves properties of non-masquerading and auditing, the members can be added and revoked dynamically. Compared with the existing threshold signature scheme,our scheme is more convenient in secret key distribution and more efficient in signing process.

Trusted Terminal Model Based on Process Protection

CHEN Ju,TAN Liang

Computer Science. 2011, 38 (4): 115-117.

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Aimed at the problem that the computer terminal is the source of the safe risk in the network system, this paper proposed a new reliable terminal model based on non-interference theory. It asserts the system's trust by the protection of static and dynamic process and non-inference among processes. The main function of static process protection is to protect the integrity of the process's code and the auxiliary file. The main function of dynamic process protection is to prevent the related data from being tampered. The function of non-inference among process is to judge the legitimacy of process alternation. The theoretical security analysis shows that the credibility of this model equals the non-interferonce model based on the trusted root. However, this model not only overcomes the trusted transfer function's irrationality of the non-interference trusted model based on trusted root, but also externalizes system static and action. Then it is more intuitive, concrete, easier to understand and in line with the actual terminal system.

Protecting Flow Based DoS Attack and Defense at the MAC Layer in MANET

YE Jin,LI Ling-qiang

Computer Science. 2011, 38 (4): 118-121.

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This paper discussed possible DoS attacks induced by IEEE 802. 11 in wireless Ad hoc networks. The protecting flow based solutions were emphatically analyzed with respect to CCA DoS attack at MAC layer. This paper proposed the principles of protecting flow design. By placing protecting flows in different positions, we compared the throughput and delay of these flows being attacked. Simulation results show that the design rule of protecting flow is effective and applicable.

Wide Differential Fault Analysis on MIBS

WANG Su-zhen,ZHAO Xin-jie,WANG Tao,WU Yang

Computer Science. 2011, 38 (4): 122-124.

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MIBS is a block cipher used in the implementation of lightweight cryptographic equipment such as RFID tag,and there has been no published paper on its security at present This paper presented the MII3S algorithm and differential fault analysis principlc,proposcd a wick fault analysis method on MIBS,and verified it through simulation. Expcriment results demonstrate; due to its Feistel structure and S-box feature, MIBS is vulnerable to wide fault attack, after injecting 32-bit fault to the 32Th and 31h round left register, 64-bit MIBS master key search space can be reduced to 21. 70-bit, the full key can be recovered after 1 second brutcforccscarch, and the fault analysis method in this paper can provide some ideas on other block ciphers using S-box.

QoS Guarantee for Data Dissemination Protocols of Wireless Sensor Networks with Mobile Multi-sink

LIN Lin,YAN Shu,NIAN Yi

Computer Science. 2011, 38 (4): 125-129.

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In wireless sensor networks with mobile multi sinks,mobile sinks roam in the network area and gather data about target via sending out rectuest to network. How to guarantee the quality of service(QoS) in processing of data dissemination is a challenging work. Firstly, based on analyzing the features of data dissemination protocols, indicators system of QoS was presented. It regards energy consumption, query success rate and service delay as core indicators. Then the relation between technologies of data dissemination protocols and core indicators of QoS was discussed. And then a consultation mechanism of QoS was proposed which can provide reference for future work. Finally, the research trends were pointed out.

Reliable Route Selection Technique for SIP Calling Connection in Wireless Mesh Networks

LI Wen-xiang,SHEN Yuan-ping,WU Jing,ZHU Han,YAN Jia-jun,ZHANG Xu

Computer Science. 2011, 38 (4): 130-132.

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Deploying SIP based application in wireless mesh networks can provide ubiquitous multimedia emergency communication in infrastuctureless areas, but unreliable wireless links may decrease communication reliability. This paper investigated the route selection method for message forwarding in wireless mesh networks. A new reliability model was proposed to measure the one-to-anyone-from-many communication for real-time calling setup with limited number of attempts. A route selection method was proposed for optimizing calling success ratio and calling setup speed,followed by theoretical analysis and comparison on upper and lower bound for communication reliability. Finally, a series of simulation experiments were designed and conducted to verify the effectiveness and superiority of the method.

Cooperation Framework for k-hop Clustered Ad Hoc Networks

LI Yong,WANG Ping,PAN Yong

Computer Science. 2011, 38 (4): 133-136.

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Based on the special structure of k-hop cluster, presented a kind of cooperation framework for k-hop clustered Ad Hoc networks. Cluster heads utilize heuristic rules to select cooperative gateway nodes and set up adaptive intercluster cooperation. Neighboring gateway nodes cooperate with cluster-heads to manage the mobile cluster members and gateway nodes. When cluster head is moving, it transmits information to an optimal replacing cluster head selected by cluster head itself. Mobil agents roam between cluster heads of network and establish a cooperation of network scale. By this way, knowledge ranges of cluster head is enlarged efficiently. Simulating results indicate that this cooperation framework can manage the mobile nodes of k-hop clustered Ad Hoc networks and provide network scale cooperation efficicntly with moderate control overhead.

Cycle Structure Characteristic of T-functions

LUO Xiao-jian,HU Bin

Computer Science. 2011, 38 (4): 137-140.

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T-functions is a mapping from rrbits to rrbits words in which cach(0≤i≤n一1) bit i of the output depends only on bits 0,1，…,i of the input. Invertible T-functions is essential ingredients in many cryptographic applications. By using the cycle structure and parameter, we proved that every cycle has length of powers of 2. Then we studied on the cycle structure of the invertible T-functions intensively, and gave two different methods for retrieving the cycle structure of the invertible T-functions f(x)mod 2k+1 on basis of f(x)mod 2k. Moreover, based on the retriving cycle structure method, we presented a determinant condition of the cycle structure characteristic 2n-tX 2t.

Improved Direct Anonymous Attestation Scheme Based on XTR System

YANG Ya-tao,CAO Lu-lin,LI Zi-chen,GUO Bao-an,XU Shu-min

Computer Science. 2011, 38 (4): 141-144.

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The existing direct anonymous attestation scheme achieves anonymous attestation using group signature,identity managed, certificate system technology and so on, which has the defect being slow implementation of the efficiency and poor safety. The computing speed of the new XTR public key cryptosystem is fast, and its safety is well.Based on the XTR public key cryptosystem, using zero-knowledge proof, this article improved the original direct anonymous attestation scheme. Demonstrated by analyzing, compared with the original mechanism, the security and implementation of this new scheme have been improved greatly.

Energy-balanced Routing Protocol for Wireless Sensor Networks in Coal Mine

WU Hua-jun,ZHANG Zi-li,LI Wei

Computer Science. 2011, 38 (4): 145-150.

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The topology of WSN in coal mine is band-type, which seriously constrained the energy balance among sensor nodes. Uneven clustering strategy can effectively balance energy consumption among nodes in the global sense,making it suitable for coal mine application. We presented an energy-balanced routing protocol on the basis of adaptive clustering mechanism which can construct unequal clusters according to the metrics such as distance to the sink node, energy level and node density. In competing cluster head, tentative cluster heads decided whether to become a cluster head according to the relative energy level compared with neighbor tentative nodes, avoiding the nodes having low energy level being cluster heads. During the data transmission stage,inter-cluster multi hop routing algorithm was designed,taking the linear topology of cluster heads in to account The algorithm not only considered the minimum energy consumption of the path but also concerned energy balance among forwarding nodes to protect those low-energy nodes. Simulation results show that the routing protocol dramatically balances the energy consumption among nodes and achieves an obvious improvement on the network lifetime.

RiMOM2:A Customizable Framework of Ontology Matching

LI Hu,ZHANG Xiao,ZHONG Qian,HOU Lei,WANG Zhi-chun

Computer Science. 2011, 38 (4): 151-158.

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As the representation of the semantic Web, the ontology is the key element of the semantic Web system, and the key for knowledge sharing and working together. However, in the real world, the inherent heterogeneous and distribution of ontology have greatly limited the knowledge sharing and data integration. In order to realize the knowledge sharing and data integration, the ontology matching has been widely studied. With the deepening of the research, numerows of effective ontology matching methods have been proposed. RiMOM2 is a multi-strategy framework of ontology matching, which integrated many effective ontology matching methods. For primary users, RiMOM2 hides unnecessary thresholds and parameters settings in order to achieve an easily manipulated ontology matching with common rectuiremenu. While for advanced users, it provides a customizable matching process function so that it can be used for ontology matching with specific requirements. hhe matching method components also arc easily extensible in the framework.

Self-adaptive Software Model and Platform Implementation for Ubiquitous Computing

SHI Dian-xi,DING Bo,ZHANG Wei,WANG Huai-min

Computer Science. 2011, 38 (4): 159-163.

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Adaptability is the main feature of ubiquitous computing software. Existing research lacks the inherent abstraction of software adaptability in the model and architecture level, which makes it difficult to provide comprehensive support for the modeling, development and running of self-adaptive software. Aiming at this deficiency in existing research, we firstly proposed the concept of Autonomous Units, which is an unified abstraction of pervasive computing entides that centers on adaptability, as well as a reference implementation model of this concept based on the component technology. And then, we proposed an architecture for self-adaptive software based on Autonomous Units, which has been described systematically in its concept, developmented and runtime level. We also implemented a micro-kernel based ubiquitous computing software platform, UbiStar, to reify and support this architecture. Finally, we used the Smart Museum application to verify the effectiveness of our work.

Quantitative Risk Analysis of Software Project Schedule Management

HE Jian-hong,BAI Xiao-ying,HU Lin-ping

Computer Science. 2011, 38 (4): 164-169.

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Project delay is still a common phenomenon in software development,which may affect seriously in software quality and cost, even result in project failure. Risk control is thus essential for project schedule management. The paper analyzed the quantitative approaches for schedule risk analysis and management. It surveyed and compared the three typical models of software project management, including PERT/CPM,Critical Chain/Buffer Management, Event Chain Methodology. Among them, the Event Chain is a newly proposed model and risk analysis method from 2004. It introduces the event model into traditional models of activitics,which captures the basic characteristics of risk occurrence and propagation. It represents a new viewpoint with a separated and dedicated risk model, and promotes a innovative approach for quantitative risk analysis.

Exception Handling Model Based on Colored Petri Net in Service-oriented Software

WU Qing,YING Shi,JIA Xiang-yang

Computer Science. 2011, 38 (4): 170-174.

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The workload of exception handling development is heavy, with complex program logic. If how to handle exception is considered just in the late design phase or coding phase, the omitted exceptions can seriously affect the overall reliability of the software. For the features of exception handling in scrviccoricnted software, it presented an exception handling model based on colored Petri net. It provides reusable exception handling model elements, by formally describing the elements of exception handling and exception handling patterns. Designer connects the elements of exception handling using exception handling patterns, which forms a complete exception handling model. The model can accurately describe the overall program of exception handling in service-oriented software,aiding to detect the defects in it.

Research and Implement of Behavior-oriented Requirements Modeling

WAN Li,WU Guo-qing,WU Huai-guang

Computer Science. 2011, 38 (4): 175-181.

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Requirements modeling is a key procedure in Requirements Engineering. "hhis paper put forward a bchaviororiented modeling methods; Ploted out problem domain of target system into several sub-domains. Viewpoints were then created in each sub-domain. Within each Viewpoint, a series of scenarios would be established according to rectuiremenu. A Scenario Behavior Model(SCBM) could then be established to specify each scenario by Behavior Description Language(BDL). A Viewpoint Behavior Model(VBM) could be constructed of all SBM within the Viewpoint and a System Behavior Model(SBM) could be constructed of all VBMs. A set of properties and their verification methods were proposed to check the correctness of behavior model and properties of the target system. Based on the methods above, a Behavior-oriented Requirements Modeling Tool(BRMT) was implemented.

Study on Defects Relate to Device Driver in Monolithic Kernel of Operating System

QIN Ying,DAI Hua-dong,YAN Yue-jin

Computer Science. 2011, 38 (4): 182-184.

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Device drivers arc major and easier faulty part of kernel. Especially in monolithic kernel of operating system,device drivers execute in supervisor mode, defects in device drivers usually result in kernel panic, greatly degrade the availability of operating system Defects in device drivers were analyzed and sorted, methods of reducing defects in device driver were introduced.

Category Theoretic Framework of Multi-language Program Generation

WANG Jin-quan,ZHENG Yu-jun

Computer Science. 2011, 38 (4): 185-187.

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The paper proposed a multi language program generation framework based on category theory. Meta-types of basic program elements are defined in the category of meta-models. Typical patterns in software development are parameterized and composed by instances of meta-models and can be transformed into different programs through refinements to different executable language categories, the computations of which arc based on categorical functors defining the mappings to language expressions,functions and types and complying with a unified contract. Thus the framework significantly improves the flexibility and reusability of program generation.

Study of Function Points Analysis Based on Fuzzy-Interpolation

CHEN Qing-zhang,LI Yi-dong,HUANG Wan-de,CHEN Qiao-yan,CHENG Rong

Computer Science. 2011, 38 (4): 188-191.

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Function Point Analysis is a widely used estimation method for measuring software size. In order to solve the problem of uncontinuity caused by complexity grade division with IFPUG(International Function Point User Group)Function Point Analysis, combined with fuzzy theory and interpolation methods, this paper presented the fuzzy-interpolation function point analysis. It is proved that the new method can more accurately estimate the number of functionpoints, and also has excellent performance on practical operability.

Business Process Optimization Modeling Based on Leveled-lanes

ZHONG Ming-yang,FU Yun-qing,JIANG Pan

Computer Science. 2011, 38 (4): 192-195.

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Business process is a hot topic in enterprise management, application and integration, and business process modeling is one of the key points in the application of business process. The paper presented a lane-based optimization modeling to the low degree of automation for process modeling and the lack of effective evaluation. hhis method can automatically model the whole business process graph according to the activities' extrapolation on the premise that the description of activities in every process is given. Then a lane process graph levelly for the possible process was made. At last, the execution cost and lane equilibrium were integrated, the best one from the leveled lane models was selected as the final business process. Combining the genetic algorithm, the author modeled the container business process. The applications show that the business process built using this modeling can effectively balance the business load and improve the operational efficiency.

Research on Software Architecture Consistency Analysis Based on π Calculus

REN Hong-min,LIU Jin

Computer Science. 2011, 38 (4): 196-198.

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Abstract As the blueprint for software development, software architecture deals with design and implementation of　high level structure of software systems. Describing and analyzing software architecture based on formal approach can　substantially detect architectural mismatches in the early stage of system development and then improve the architecture quality effectively. Based on formal architectural description language π ADL and taken into consideration of the characteristics and requirements of software architecture, a collection of concepts and process relationships were defined for　many using π calculus theory as a theory foundation, then eight static check methods to determine consistency of π ADL　architecture specifications were developed, which can significantly raise the qualities of architectural specifications and　system composition.

Study on Evaluation Model of Software Requirement Analysis Risk Based on Neural Network

XIAO Wei-na,ZHANG Wei-qun,WANG Ling-ling

Computer Science. 2011, 38 (4): 199-202.

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It is an important problem that how to ascertain the potential risks of the requirement analysis phases and reduce its opposite forces as low as possible in requirement analysis. We proposed an evaluation model of software requirement analysis risk, which combines Fuzzy Logic with BP neural network based on index system of risk assessment of requirement analysis. At last, the results of experiment demonstrate the feasibility and validity of the approach.

Modeling and Analysis for the Process Formal Semantics of OWL-S Based on Extended CPN

BAO Ai-hua,WANG Xiao-xuan,WEN Ai,DING Ke,LIU Peng

Computer Science. 2011, 38 (4): 203-208.

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The process formal semantics of OWI-S is a key issue in the research on semantic Web service. This paper analyzed the current work and existing problem of research on OWL-S process formal semantics, and proposed an extended Colored Petri net, which is called Process Model net(PM net) , to model and analyze the process formal semantics of OWL- S. According to the characteristic of OWL- S process modcl,PM net extended the transition and fire rule of basic CPN, so that, the atomic process, composite process and data flow of OWL-S process model can be mapped to PM net equally. The method to check consistency of OWL- S process formal semantics based on PM_net was also introduced. The work of this paper provided reasonable theroy foundation for the evolution ofOWL-S, semantic Web service composition and verification.

Research of Stochastic Fractal Dimension Calculation Algorithm in Data Stream

NI Zhi-wei,GONG Wei-feng,ZHOU Zhi-qiang,TANG Li-yang

Computer Science. 2011, 38 (4): 209-212.

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Fractal dimension can describe the data set effectively and can reflect the hidden regularity of the complex dato set. Data mining algorithms based on fractal theory arc usually related to the calculation of fractal dimension. But most of the existing fractal dimension calculation algorithms are with high time complexity and space complexity,which greatly reduces the efficiency and is not applicable for data stream with high-speed and massive data. In this paper, scveral existing fractal dimension calculation algorithms were analyzed and a stochastic fractal dimension calculation algorithm were proposed to fast estimate the correlation dimension in fixed space. The comparative experiment and analysis demonstrate the effectiveness of this stochastic fractal dimension calculation algorithm.

Parsing DOM Tree Reversely and Extracting Web Main Page Information

ZHANG Rui-xue,SONG Ming-qiu,GONG Yan-lei

Computer Science. 2011, 38 (4): 213-215.

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To extract main content from HTML Web page, generally, we should parse HTML, visit the whole DOM tree, and extract the data from the tree by distribution. However, this method separates the two processes of parsing and extracting and therefore restricts the speed. Actually, parsing the whole DOM tree is unnecessary. Here we supposed the algorithm of parsing DOM tree by reverse order. Then combining with the theory of DOM similarity and the traditional method of parsing DOM we parsed IWM tree with both normal order and reverse order, and at the same time we fixed the positions of other targots and got them. On the one hand, this method only parses part of DOM tree, so it reduces the time cost by parsing. On the other hand, we do not have to visit the whole tree to search the target information, as a result, it saves the searching time. Overall, this method improves the speed much. At the end of this paper, we gave the proof on the superiority of this method.

Fast Algorithm for Mining Association Rules Based on Vertically Distributed Data in Large Dense Databases

CUI Jian,LI Qiang,YANG Long-po

Computer Science. 2011, 38 (4): 216-220.

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To further reduce both CPU and I/O overhead in the process of mining the association rules on the large transaction database by the traditional algorithm, an improved algorithm of association rule mining based on vertical data layout named VARMLDb(Vertical Association Rule Mining for Large Databases) was suggested. In the proposed algorithm,after dividing the database into several partitions each of that is suitable for the current memory, the algorithm combines directed acyclic graphs and diffset(difference of tidlist sets) which belongs vertical data layout structure for storing and computing frequent item sets, which not only greatly cuts down the required memory size used to save intermediate results but also solves the low efficiency problem during the mining dense database by traditional vertical data mining algorithm, so that the algorithm is more effective for large dense databases. As a result of drawing the advantages of CARMA(continuous association rule mining) algorithm, the algorithm needs to scan the database for only twice.Experimental results show that the algorithm is correct, and in the large dense transaction databases, VARMI_Db algorithm has higher implementation efficiency. Continuous association rule mining algorithm, Directed acyclic graphs, Diffset plumb, Vertically distributed data, Dense database

aH-Algorithm, An Extended a-Algorithm to Mine Hidden Tasks

MA Hui,TANG Yong,WU Ling-kun

Computer Science. 2011, 38 (4): 221-225.

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A thorough understanding of the way in which a workflow process is executing is essential to workflow rnanagement.By extracting information from workflow traces, such as system log data, workflow mining aims to discover the actual behavior of a workflow process. One of the challenging problems in workflow mining is to mine hidden tasks.Based on the traditional a-algorithm, an extended one which is called aH-algorithm to mine hidden tasks was proposed.After studying the situations where a hidden task may appear,the aH-algorithm inserts hidden tasks by judging the presences of parallel tasks.The mined workflow model was refined by fusing the same hidden tasks and removing the redundant ones.A prototype based on aH-algorithm was implemented.Experiments in the end show the fasibility and validity of the proposed algorithm.Furthermore,the restriction of the algorithm and related future work were also discussed and pointed out.

Performance Analysis of Workflow Process Based on Stochastic Well-formed Workflow

SHA Jing,PANG Shan-chen

Computer Science. 2011, 38 (4): 226-229.

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Quality-of-Service(QoS) in workflow processes encompasses various non-functional issues such as performance, dependability and security, etc. I}he management of QoS metrics directly impacts the success of services participating in workflow-based applications. Therefore,when services are created or managed using workflows or Web processes, the underlying workflow engine must be able to estimate, monitor, and control the QoS rendered to customers. An approach was given to give QoS of workflow processes based on the decomposing algorism and numerical analysis of stochastic well-formed workflow(SWWF) model.

Active Learning for Multi-label Classification Based on SVM's Expect Margin

LIU Duan-yang,QIU Wei-jie

Computer Science. 2011, 38 (4): 230-232.

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Classification is one of the key techniques of data mining. It requires a large number of training samples to oblain a favorable classifier, but it is resource-consuming to create label for each sample, it is even more so for multi-label samples. In order to reduce costs, it should find the most informative samples which can represent the classes. The classificrs which arc based on SVM, the larger margin, the classifier's accuracy will be poorer. hhis paper proposed an acfive learning method based on SVM's expect margin which relies on current classifier, select samples that can reduce classifier's margin fastest hhe experimental results show that the method based on expect margin outperforms than other active learning strategy based on decision value and posterior probability strategy.

Structural Query for Multiversion X1VIL Document Based on Index

DING Zheng,ZHOU Hong

Computer Science. 2011, 38 (4): 233-235.

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This article mainly discussed how to break through the limitation of version recovery and conduct complicated structure inquiry in any version of XMI_ documents. Surrounding the thesis, it introduced the common method of current XMI_ document version management, then brought out and implemented a new index method based on numbering schema of multi-version XML file,finally refered structural joining algorithm into XML version control field and improvedthree classical structure joining algorithm,all of which support complicated structure inquiry without version recovery.We analyzed and compared their searching efficiency by experiment, and proved that index searching algorithm can avoidredundancy in searching as much as possible.

New Fusion Approach for Conflicting Evidence in D-S Theory of Evidence

JIANG Li-ming,HE Jia-lang,ZHANG Hong

Computer Science. 2011, 38 (4): 236-238.

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A new method was developed for dealing with seriously conflicting evidence when the Dempster combination result can not identify the actual conditions. The method combines the advantages of justification of evidence information and combination rules. The reliability of evidence, computed by a conflict matrix, is taken as discount factor to correct the belief functions. And then the problem of space and weight for conflict redistribution is addressed based on the idea of distributing local conflict to local focal elements. Compared with the existing methods, the new method can applied toboth cases of conflicting and coincidence. And the numerical simulation shows that the method improves the reliability and rationality of combination results,and also accelerates convergence and reduces the decision risk.

Half P-sets(XF，X) and Internal-truth Degree Ring Characteristics of Information

LI Yu-ying,SHI Kai-quan

Computer Science. 2011, 38 (4): 239-243.

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P-scts(Packct sets) is a set pair (XF，XF) composed of internal P-set XF (internal packet set XF)and outer Pset XI' (outer packet set XI' ) , or (XI' , XI' ) is P-sets. P-sets has dynamic characteristics(XI' has internal dynamic characteristic and了has outer dynamic characteristic). P-sets has been applied in many fields of dynamic information systans. There is a class of information system which has internal dynamic characteristic but has not outer dynamic characteristic. To study the class of information system, Half P-sets(half packet sets) was proposed by improving and simpliEying P-sets in this paper. Half P-sets is a set pair composed of internal P-set XF and finite general set X, or (XF , X) is Half P-sets. Half P-sets has internal dynamic characteristic. hhis paper gave the relation between Half P-sets and finite general set, the relation between Half P-sets and P-sets. By using Half P-sets, the concepts on information internal-truth degree and information internal-truth degree ring were given. Moreover,the information internal-truth degree ring theorems, the criterion of internal-truth degree and the criterion characteristic coefficient about internal-information recovery-reduction. Finally, the application of internal-truth degree ring about internal-information recovery-reduction was provided by employing these results. Half P-sets is a new mathematical method and mathematical model for researching the class of dynamic information system. Half P-sets has good application foreground in the class of dynamic information system.

Research on Multi-concept Learning Based on Inter-concept Relation

CHEN Dan-wen,LIU Ran,YUAN Zhi-min, DENG Li-qiong,WU Ling-da

Computer Science. 2011, 38 (4): 244-248.

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Multi-concept learning is a very important technology of video retrieval. This paper gave a method of multi concept learning based on inter-concept relation. First, analysed the types of inter-concept relation in large-scale multi media lexicon, then got ctuantitative analysis with TRECV)D2005 annotation data and Columbia374 data. Second, selected correlative concepts to build context based conceptual fusion detectors, then got weights with reliability of detectors.At last, fused the two detectors with visually similarity. The results show that the proposed method achieves more remarkable and consistent improvement.

Rapid Collaborative Scientific and Technical Literature Push Mechanism Based on Intelligent Agent

XU Xiao-long,ZHAO Chang-yao,GENG Wei-jian,CHENG Chun-ling

Computer Science. 2011, 38 (4): 249-253.

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The current scientific and technical literature network-sharing platforms have a mass of papers, which is difficult for users to get what they really need. We presented a new Rapid collaborative scientific and technical literature push model based on intelligent Agent_ This model adopts Intelligent Agent technology to build the User Agent, Data Transfer Agent,Information Evaluation Agent,Information Analysis Agcnt,Server Monitor Agent and Data Mining Agent, to establish an effective collaborative relationship between clients and servers, provide scientific and technical literalures jointly for each users meeting their needs perfectly. We also proposed a Literature-Readers Matching Assessment Algorithm(LRMAA) , which is to comprehensively consider the subscription information provided by user initiatively,the user's reading history, the objective assessment of literature as well as the literature publishing time, to get the matching vector,resulting in a true and accurate access to the user's research interests and focuses in time to provide users with the most valuable, suitable and high-quality scientific and technical literature information. This paper first analyzed the current network Information Pull and Push methods, and then introduced the Intelligent Agent-based rapid collaborative scientific and technical literature push model, at last, discussed LRMAA in detail about all parameters computing of the vector.

Method of Situation Recognition Based on Hidden Markov Model

HE Yan-bin,YANG Zhi-yi,MA Hui,WANG Hai-peng,YU Zhi-wen

Computer Science. 2011, 38 (4): 254-256.

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Hidden Markov Model, as a statistical model, can get the probability of hidden status by calculating the sequcnce of observed status. In this paper, a recognition approach based on HMM was proposed to infer situation in smart space. The approach infers situation by calculating partly contexts of system-related, using HMM to model the hidden situations. We designed the recognition algorithm based on HMM. Our experimental results show that this method can make a good performs and get a higher efficiency.

Modeling and Verification of Batch System

U Xian-feng,LEI Li-hui, LI Yong-ming

Computer Science. 2011, 38 (4): 257-259.

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The model of simple batch systems is the foundation of its performance evaluation, simulation, scheduling,and control research. This paper introduced a mathematical model named batch automata for simple batch systems, andgave an algorithm for translating a batch automata into a Kripke structure, and completed the model checking of batch system based on the Kripke structure to verify the reasonable property, i. e.，both fair and efficiency.

Multi-objective Particle Swarm Optimizer Based on Adaptive Crowding Grid

LIU Yan-min,SHAO Zeng-zhen,ZHAO Qing-zhen

Computer Science. 2011, 38 (4): 260-262.

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Multi-Objective Particle Swarm Optimizers(MOPSOs) easily converge to a false Pareto front(i. e.，the equivalent of a local optimum in single objective optimization) , and converge slowly. So, we proposed a multi-objective PSO based on adaptive crowding grid(ACG-MOPSO for short). The proposed algorithem has the following characteristic: adaptive crowding grid was used to define the diversity of particles in the external archive to keep the size of the external archive, and the global best particle was assigned by the informations of density and crowding distance to improve the probability of flying to Pareto front Simulation results show that the ACG-MOPSO algorithm is able to find better solutions compared with other algorithms.

Interval-valued (α,β)-fuzzy Lattice Implication Subalgebras

LIU Yi,XU Yang,QIN Ya

Computer Science. 2011, 38 (4): 263-266.

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The idea of "quasi coincidence" was applied on interval valued fuzzy sets, a new kind of fuzzy lattice implication subagebras was proposed, called interval valued (α,β)-fuzzy lattice implication subalgebras. Some properties of this new fuzzy lattice implication algebra were investigated. The relations between (α,β)-fuzzy lattice implication subalgebra and lattice implication subalgebras were studied. Some equivalent characterization theorems of interval valued (α,β)-fuzzy lattice implication subalgebras were established.

Property of Liveness in Sequential Resource Allocation Systems Based on Petri Net

YUE Hao

Computer Science. 2011, 38 (4): 267-271.

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Sequential Resource Allocation Systems with Multiple Resource Acquisitions and Flexible Routings(C/D-RAS) arc a kind of common system with higher complexity. The liveness problems of two C/D-RAS were investigated in this paper. The Petri net models of the two C/D-RAS were defined as the marked S' PGRz nets pair, which is denotedby ((N1,M01)，(N2，M02)).With the help of the resource conversation attribute of the marked S3 PGRz nets and a sufficicnt and necessary condition of transition enabling, it was proved that the legal firing sequences of transitions in(N1，M01)and(N2,M02)are consistent As a result, the final conclusion tells us that(N1,M01)is live, if and only if(N2,M02)is live. Finally,the potential application of the conclusion was briefly introduced.

Locality Preserving Discriminant Analysis Algorithm for Feature Extraction

JIANG Sheng-li, KUANG Chun-lin,ZHANG Jun-ying

Computer Science. 2011, 38 (4): 272-274.

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To address the limitation that locality preserving projection(LPP) algorithm belongs to unsupervised,a novel approach,named as locality preserving discriminant analysis(LPDA) was proposed. LPDA algorithm absorbs the common characteristics of the manifold learning algorithm and maximum margin criterion(MMC),and can project the high-dimensional face data into the low-dimensional subspace. The new sample can be processed and the small sample size problem can be prevented. Compared with several classical and related methods, the experimental results from Yale, UMIS T and MI T face databases show that I_PDA algorithm can extract the more efficient features for face recognition while the dimensionahty is reduced, and obtains much higher recognition accuracies and stronger power of classification.

Face Recognition Based on Shape Feature

DONG Wei-jun,ZHOU Ming-quan,GENG Guo-hua

Computer Science. 2011, 38 (4): 275-277.

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In order to resolve the shapcbased face recognition method's descriptor shortcoming that is not stable and the variance with respect to transform, scaling, and rotation, multi scale edge images and image's characterized descripfor were got through wavelet transform, classification feature was extracted by improved linear discriminant analysis in wavelet transform domain, at last geting the recognition result. The PIE face database was used to test the proposed method, the experiment results show that new method which is based on wavelet transform has better recognizing effect, the new descriptor which can describe image's shape and spatial distribution message very well has the excellence result of stable and the respect to transform, scaling, and rotation.

Robust Image Watermarking Based on Improved Invariant Centroid and Wavelet Domain

XIA Weil,LU Hong-wei,XIE Chang-sheng,ZHAO Xiao-sha

Computer Science. 2011, 38 (4): 278-281.

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A geometrically robust blind watermarking algorithm was proposed using translation, rotation and scaling invariant property of relative coordinate of the invariant centroid. With certain level wavelet decomposition according to the length of the watermark bits, after modifying some selected coefficients in the lowest frequency of the last level for its robustness to the interference, the modified coefficients were applied to obtain the watermarked image by wavelet reconstruction. With the improved invariant centroid based characteristic matrix and the Rijndael encryption,a related binary logical table was produced. As the secret key, the table was used to apply to the third party for copyright proteclion. This arithmetic can extract the watermarking without the original carrier image and the original watermarking. Experimental results show its low time complexity and robustness to the common attacks such as JPEG compression, cropping and added noise, as well as the geometric attacks such as translation, rotation and scaling.

Research on Feature Extraction of Defects on Wood Surfaces Based on Image Fusion

XIAO Bin-jie,SHU Wei-qun

Computer Science. 2011, 38 (4): 282-285.

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There are sometimes defects such as cracks, Bump, etc on the wood surfaces in the production process of wood and furniture. The different texture of the wood surfaces and the reflex light of the varnished surfaces enhance the difficult of defects detection on Wood Surfaces. In order to inspect the defects,we illuminated the surface of wood from four different angels and gained the respective four images for more detail information. A fusion method for the image series based on principal component analysis(PCA) was presented in this paper,which fuses the complementary information of the image series including the four images and gets a result with more distinct defects. This method introduces a principal component subspace and reserves original information when extracting mainly information. The emulated resups show that more distinct features can be extracted from the four images of a same surface by fusing the image series with PCA. I}he extracted features can be used to automatically detect and classify the defects on the wood surfaces in the future task.

Novel Face Recognition Method Based on Fuzzy 2DPLA

SONG Jia-dong,LI Xiao-juan,XU Pcng-fei,ZHOU Ming-quan

Computer Science. 2011, 38 (4): 286-291.

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In this paper, a novel method based on fuzzy 2DPLA was proposed which embeds the degree matrix of membership based on the fuzzy set into 2DPCA and 2DPCA methods. This method first calculated the degree matrix of membership using the fuzzy KNN method. In the sequcl,the degree matrix of member was embedded into 2DPCA and 2DLDA for reducing the dimension from horizontal and vertical two directions of image matrix, respectively. Last but more importantly, we used the F-norm classification measure based on the matrix instead of the traditional 2-norm measure based on the vector. In experimental phase, Yale Face Database B, ORL and FERET Face Database were used to test the new method. Experimental results demonstrate that our method has better robustness and higher recognition rate than the state-of-art methods.

Research on Infrared Small Target Detecting in the Sky in NSCT Domain

LIU Gang,LIANG Xiao-geng,ZHANG Ling-ling

Computer Science. 2011, 38 (4): 292-294.

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In order to solve the practical problem of the infrared small target's detecting in the sky,a detecting algorithm based on the NSCT(nonsubsampled contourlet transform) was proposed. Firstly, taking advantage of the excellent property of the transform, this algorithm analyzed the different property of the NSCT coefficients of noise, background edge and signal, then computed the normalized correlation coefficients between scale for the transform cocffidents. Subsequently, according to the adaptive method of threshold, the coefficients of background edge and noise were suppressed and then the image which includes the enhanced target was acquired by the inverse transform In the end, taking the target area into account, the reconstructed image was partitioned and the final detecting result was acctuired by considering the position correlation of the target between frames. Experimental results show that the method given by this paper can detect small target accurately. Compared with some traditional method, it has certain advantage in background suppressing and can acquire high SNR(signal noise ratio) value.

Two-dimension Abstraction Theory for Parameterized System

PANG Zheng-bin,QU Wan-xia,GUO Yang,YANG Xiao-dong

Computer Science. 2011, 38 (4): 295-301.

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In order to preserve interesting properties of a system under consideration during verification, it is necessary to establish an equivalent relation between models. Two-dimension abstraction for parameterized system,where the size of the state transition graph for individual process is decreased independently at first, and the whole system composed of reduced processes is then abstracted based on the design principle of parameterized systems, thus avoiding the construction of the complete state space that might be too big to fit into memory. The paper gave the correctness and soundness proofs of two-dimension abstraction. It was shown that simulation relation exists between TDA model and concrete model, and TDA model is weak preserved with respect to ACTL* formula. Importantly, a singlcindcxed ACTL* formina satisfied by TDA model, is also satisfied by concrete models with arbitrary replicated(and a constant number of non-replicated) processes. This work lays the theoretical basis for simplifying parameterized system verification.

Source-to-Source Compiling Approach to Extend OpenMP/Fortran with Transactional Memory

HUANG Chun,JIA Jian-bin,PENG Lin

Computer Science. 2011, 38 (4): 299-302.

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OpenMP Fortran directive APIs were extended to support transactional memory. I}his is the first time to introduce TM into Fortran language. The source-to-source translation method was involved in the compiler prototype named FortranTM EXCLUDED clause was introduced and SCHEDULE clause was extended with transaction size parameter. Experiment results show that FortranTM interfaces facilitate transactional programming and provide impressive performance profits.

Operating System Structuralization Research Based on Non-interference Model

SUN Yu,HU Jun,CHEN Ya-sha,ZHANG Xing

Computer Science. 2011, 38 (4): 303-306.

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Structural protection of operating system is currently a difficult problem in security field. This paper studied a process execution environment model based on hierarchy isolation, and gave definition and conditions of process environment security. Then we formalized structural requirements of process environment, and proved that a secure process environment can be available by structured method proposed. Finally combined with classic non-interference theory, the security model was extended from process environment to the whole system.