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Dynamic model of a rotor-journal bearing system under base shock excitations was established. Energy differential equations were derived by applying Lagrange equation with FE in space domain. Bending and shear deformation energy of shaft element were taken into account. Inertia force due to rotor mass eccentricity was introduced and treated as a generalized external force. Oil-film force was determined...
This paper extends the transfer matrix technique (TMT) to the shock response analysis of a large complex propulsion shaft system under base shock excitations by a transfer matrix-Newmark formulation itegration method. In order to eliminate the numerical instability of TMT, the transfer vector {fT : ëT}T is used, instead of the traditional one {fT : eT}T. For the shock response computation of the...
To investigate the influence of loading opportunity of shock excitations on dynamic responses of rotor-bearing systems subjected to base shock excitations, dynamic differential equations of a rigid rotor-bearing system were established. Gyroscopic effect and mass eccentricity of the rotor were considered. Shock responses were obtained by numerical simulation. Four cases are investigated that will...
The conventional Newmark method based on average acceleration concept cannot be directly applied to solve state-space first-order differential equations, which contains no explicit acceleration terms. Combining with a Newmark iteration algorithm based on average velocity concept, a Riccati-transfer matrix method was proposed to obtain transient response of rotor systems under base shock excitations...
This article aims at exploring a method to solve the key problem of enterprise knowledge management with knowledge sharing as the start and wiki as a consultant. This article describes knowledge sharing as the central position of knowledge management and analyzes the barriers of enterprise knowledge sharing. Then introduces the feature and usage of wiki and illustrates the advantages of wiki when...
The paper provides background theory related to learning and Web 2.0 technologies and describes an innovative application of them to increase people's awareness of Web 2.0 technologies. It is to find answers for two questions: (1) is Web 2.0 technologies appropriate in supporting social learning? And (2) how Web 2.0 supports the process of social learning? Based on the four components of Boisot's...
The purpose of this study is to analyze the motivations of library tacit knowledge transfer and to explore how to utilize them to improve efficiency of tacit knowledge transfer. Beginning with the scope of the library tacit knowledge, this paper constructs a motivation model based on analyzing the process of library knowledge transfer. Then the two aspects of the model, including intrinsic motivation...
Standardization is the only way for the development of e-commerce, but whether domestic or international e-commerce standards have not satisfactory. This article analyzes the e-commerce standardization problems and obstacles from 3 parts: position and classification, formulation, monitoring and implementation. This article accounts that the source of the problems is the contradiction between e-commerce...
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