摘要：
Frequent itemset mining is a critical step in association rule mining and plays an important role in many data mining tasks including strong rules, correlations and sequential rules. Diffset is an efficient frequent itemset mining algorithm which uses vertical database layout. An efficient hybrid algorithm DiffsetHybrid is brought out. The tests indicate that the new algorithm shows good performance with both sparse datasets and dense datasets.
期刊：
2007 IFIP INTERNATIONAL CONFERENCE ON NETWORK AND PARALLEL COMPUTING WORKSHOPS, PROCEEDINGS,2007年:809-812
通讯作者：
Xiao, Hongguang
作者机构：
[Xiao, Hongguang; Jian, Wang] Xiangtan Univ, Sch Math & Calculat Sci, Xiangtan 411105, Peoples R China.;[Xiao, Hongguang] Changsha Univ Sci & Technol, Sch Elect & Informat Engn, Changsha 410076, Hunan, Peoples R China.;[Tan, Zuowen] Jiangxi Univ Finance & Econ, Dept Comp Sci, Nanchang 330013, Jiangxi, Peoples R China.;[Tan, Zuowen] Chinese Acad Sci, AMSS, KLMM, Beijing 100080, Peoples R China.
通讯机构：
[Xiao, Hongguang] X;Xiangtan Univ, Sch Math & Calculat Sci, Xiangtan 411105, Peoples R China.
会议名称：
IFIP International Conference on Network and Parallel Computing
会议时间：
SEP 18-21, 2007
会议地点：
Dalian, PEOPLES R CHINA
会议主办单位：
[Xiao, Hongguang;Jian, Wang] Xiangtan Univ, Sch Math & Calculat Sci, Xiangtan 411105, Peoples R China.^[Xiao, Hongguang] Changsha Univ Sci & Technol, Sch Elect & Informat Engn, Changsha 410076, Hunan, Peoples R China.^[Tan, Zuowen] Jiangxi Univ Finance & Econ, Dept Comp Sci, Nanchang 330013, Jiangxi, Peoples R China.^[Tan, Zuowen] Chinese Acad Sci, AMSS, KLMM, Beijing 100080, Peoples R China.
会议论文集名称：
IFIP International Conference on Network and Parallel Computing NPC
摘要：
In the paper we analyze the security of C.-L. Hsu et al.'s threshold proxy signature scheme. The scheme suffers from universally forgery and does not hold nonrepudiation. An adversary can forge (t, n) threshold proxy signature on any message m. We propose an improvement to remedy the weakness of C-L. Hsu et al.'s scheme.
期刊：
CHALLENGES OF POWER ENGINEERING AND ENVIRONMENT, VOLS 1 AND 2,2007年:320-323
通讯作者：
Lu, Xuxiang
作者机构：
[Huang, Shuhong; Lu, Xuxiang] Huazhong Univ Sci & Technol, Sch Energy & Power Engn, Wuhan 430074, Peoples R China.;[Li, Luping; Lu, Xuxiang; Huang, Wenjun] Changsha Univ Sci & Technol, Sch Energy & Power Engn, Changsha 410076, Hunan, Peoples R China.
通讯机构：
[Lu, Xuxiang] H;Huazhong Univ Sci & Technol, Sch Energy & Power Engn, Wuhan 430074, Peoples R China.
会议名称：
2007杭州国际动力工程会议(The International Conference on Power Engineering 2007)
会议时间：
2007-10-23
会议地点：
杭州
会议论文集名称：
2007杭州国际动力工程会议（The International Conference on Pow
关键词：
Steam turbine;Integrally shrouded blades;Damping structure;Dry friction;Characteristics of damping vibration
摘要：
The principium of damping vibration and the effects of damping vibration in damping structure of steam turbine integrally shrouded blades are investigated in this paper. Firstly, according to the characteristics of dry friction damping structure local-connection being nonlinear element and damping shroud contact interface being unparallel to the direction of blade vibration. The physical and kinetic models of the damping structure of integrally shrouded blades were established. Then, qualitative and quantitative analysis of the characteristics of damping vibration is explored by means of equivalent linearization and harmonic balance method. The research findings show that the contact tangential rigidity and normal force influence the vibration characteristics of blade, but the angle of shroud interface and direction of blade vibration and friction coefficient have no impacts on the vibratory characteristics of blade, only affect the optimal normal force and its distribution interval, the amplitude and frequency of external excitation force impact complexly on the vibratory characteristics of the damping structure. The results of this paper might provide theoretical guidance and suggestions for reasonable design in the damping structure of steam turbine integrally shrouded blades.
会议名称：
第二届国际结构状态评估、监测与改进会议(The Second International Conference on Structural Condition Asessment,Monitoring and Improvement)
会议时间：
2007-11-19
会议地点：
长沙
会议论文集名称：
第二届国际结构状态评估、监测与改进会议（The Second International Confe
摘要：
Orienting to the specific characteristics of behaviors of externally prestressed concrete bridges under segmental construction, a joint model of the same displacement constraint is proposed by using freedoms coupling and mixed coordinate systems. Considering material nonlinearity, the second-order effect of external prestressing cables and the joints, both 8-node plane quadrilateral equal element and one-dimensional truss element are used for concrete and internal or external tendons. Then a finite element model is established and programmed, which is capable of performing the nonlinear all- stage analysis of segmental construction externally prestressed concrete bridges. Based on the above theory, main parameter influencing the ultimate load of the concrete bridges is analyzed and some advices are also given in the paper.
期刊：
Proceedings of the 26th Chinese Control Conference, CCC 2007,2007年:26-29
通讯作者：
Wang Zhengwu
作者机构：
[Luo Dayong; Wang Zhengwu] Cent S Univ, Sch Informat Sci & Engn, Changsha 410075, Hunan, Peoples R China.;[Huang Zhongxiang; Luo Dayong; Wang Zhengwu] Changsha Univ Sci & Technol, Sch Traff & Transportat Engn, Changsha 410076, Hunan, Peoples R China.
通讯机构：
[Wang Zhengwu] C;Cent S Univ, Sch Informat Sci & Engn, Changsha 410075, Hunan, Peoples R China.
会议名称：
26th Chinese Control Conference, CCC 2007
会议时间：
July 26, 2007 - July 31, 2007
会议地点：
Zhangjiajie, China
关键词：
artery system;colored hybrid Petri nets;phase module;fuzzy rules
摘要：
Urban artery system, which is characterized by dynamic, concurrence and synchronization, is a hybrid dynamic system involving discrete and continuous behaviors. The dynamic actions of the urban artery system can be modeled through Petri nets. Therefore, modeling and control of the urban artery system based on Petri nets are discussed in this paper. First, a phase module is modeled using hybrid Petri nets according to modularization methods. Then, a distinct and readable model of the urban artery system is presented after coloring the phase module. Moreover, to scheme signal parameter, fuzzy theory is embedded into Petri nets by using fuzzy rules to define some transitions of Petri nets.
