A New Estimation Method of Transient Voltage Stability Limit Clearing Time

Critical clearing time index is one of the indices to assess transient voltage stability. At present it is mainly calculated based on the instantaneous value after transient voltage instability or the steady state valueafer fault clearing time. So a new method to estimate the critical clearing time is presented which is correspongding to the induction motor minimum slipvalue in the fault. It can forecasttransient voltage instability,and has higher precision comparing whithquik criterion and analytical method. The simulation results of IEEE 30-bus system verify the effectiveness of the stated method. .CLC number: TM 73 Document code: A Article ID: 000-3673(2013)00-0000-00

A Knowledge-Based Approach of Automation Design of Aircraft Standard Components

To solve the problem that knowledge of standard components cannot be quickly applied to design process of aircraft, a novel approach based on knowledge is proposed from the instantiated requirements of standard components. Knowledge-based model based on semantic of standard component is described, which is composed of parameters, rules, solid model and assembly information. The information model is expressed and stored based on XML. Knowledge-based model is provided to support the specifications determination, semantic modeling of solid model and batch assembly of standard components by loosely coupled manner. Design knowledge is seamlessly, quickly applied to the instantiated process of standard components. Effectiveness of the proposed model and method is verified by an aircraft design example of standard components. CLC number: TP391.7 Document code: A

Design and Implementation of Urban 3D Visualization System Based on ArcGis Engine

t is a development trend of urban planning from 2D to 3D on the basis of introduction and their combinative application of ArcGIS and SketchUp. In this paper, designing and implementing the urban 3D visualization system, devising the system frame, introducing the key technology, through the instance, showing that the system has practicality and generality. CLC number: P208 Document id code: B

Research of Scheduling Management in Warship Scheduled Repair Project

The buffer setting and management mechanism in Critical chain method was combined with practical progress vanguard line in this paper. Then the information statistical and analysis methods of project schedule was given, and the methods are applied in project scheduling management of warship scheduled repair. With the application analysis in maintenance project shows that this methods can identify the activity chain which really lead to the lag of project scheduling. This shows that the method was given in this paper presents an applicable value for actual warship scheduled repair project scheduling management. CLC number: U672 Document id code: A

The Reliability Prediction of Component Cooling Water System (CCWS) Based on Copula

According to correlation between the equipment of CCWS, this paper uses Copula to describe correlation of the system, establishes the reliability prediction model of CCWS and does the quantitative calculation. Analysing the results shows that the reliability of redundancy system is much higher than that of single component, but dependent failures between the equipment decrease the reliability of system. And also shows that this model can be perfectly used in the reliability prediction of CCWS. CLC number: TL364+.1 Document id code: A

Experimental Study of Finding Best Way of Radiation Seeds with HVEF

Norder to find the best high-voltage electrostatic radiation seed program, to select two different kinds of cucumbers, vegetables, paddy rice seeds, each seed be divided into 5 experimental groups, and be treated by high voltage electrostatic field (HVEF) at different field strength and time, and testing and statistics of the seeds vigour at germination stage. The results indicated that the greater the radiation field to same seed, the shorter radiation time is required, and vice versa. For each species, E•t tends to a constant (the constant is different in different species). Be proved by mathematical derivation that the HVEF radiation transport essentially energy to the seed, and then will be able to find the best way for HVEF radiation seeds. CLC number: S129 Document code: A.