An Improved Method of the Transient Waveform Analysis in Power Systems

The angular frequency and decaying constant of each copmonect for the transient waveform in power systems were obtained by using the discrete Fourier transform; the amplitude and phase angle were calculated in the linear curve fitting method. And all of the parameters obtained above were treated in an unified optimization by using the curve fitting optimization of the least square method of general nonlinear funcrion so as to get the results of waveform analysis. Two examples are included.     

Application of Multi-vertical-line-element Model of RC Walls and Discussion on IT

The inelastic dynamic response analysis program for frame-shear wall structures developed by the authors is introduced firstly, in which the multi-vertical-line-element model was adopted for shear walls and the refined single-component model was used for beams and columns in frame.By analyzing three-story structural models tested in shaking-table in a famous foreign research institute, the validity of the modeling of shear wall in the program was verified. The analytical results indicate that the inelastic dynamic responseof shear walls under random ground motion input can be predicted effectively withthe program. Finally, with the preliminary discussion of some key points in modeling of shear wall, some suggestions areput forward for further improving and refining the multi-vertical-line-element model.     

Analysis and FEM Simulation of the Forming Process of Front Bumper Bracket

The processing characteristics of the front bumper bracket are analyzed,and a reasonable process scheme is worked out.The three-dimensional sheet metal forming analysis software PAM-STAMP are adopted to simulate the bracket's drawing process.Then the surface of die is proved fine through analyzing the FLD diagrams and the forming results.An economical and optimized die structure is decided,and a complete set of dies of the bracket is designed.The spacing block is added in the sizing mold,which control the size precision of end products and assembling columns actively,and finally the certified products.The material utility and the labor productivity are raised,the production cost is saved,and the mold design quality and the efficiency are improved effectively.     

Analysis of the Sediment Development and Trend In Jinshajiang River Drainage Area

Jinshajiang River, which has a drainage area of 485,100 Km 2, average flux of 142.9 billion m 3, and soil conveyance of 247 million t/a, is the largest branch of Changjiang river. It is also the largest soil resource of the Three Gorges reservoir and upper reach of Changjiang River. To research the development and trend of Jinshajiang sediment not only has a relation to Jinshajiang water resource strategy, but also has important meaning to control the silt in Three Gorges reservoir and the Changjiang water resource development. The paper statistically analyses the flux and sediment conveyance of the Pingshan station, which is the primary hydrological station in the Jinshajiang River Drainage Area. Through several non-parameter statistical methods such as Spearman order correlativity check, Kendell order correlativity check, and linear regression check, the paper concludes that the sediment evolvement trend of Pingshan station is not distinct.     

Synthetic Application for Analysis Methods of the Planar Mechanism Overconstraints

Overconstraints exist widely in planar closed chain mechanisms and mechanical systems result in a series of detrimental influences on behavior of machines, and attention is given to them by machine designer. Some analysis methods of overconstraints in planar closed chain mechanisms are presented, and more study due to the faultiness of these methods. In accordance with faultiness of two common kind of methods, formulas method and loop analysis method of degrees of freedom, and by combining these two methods, an useful mechanism overconstraints analysis method which is convenient for computer aided overconstraints analysis is gained via research on the two methods thoroughly and systematically, and some new views about mechanism overconstraints analysis are presented.     

Operational Deflection Shape Analysis of Large Scale Electromechanical System

Operational Deflection Shapes of large scale electromechanical system can be ex-tracted directly from multipoints response of the operating system by using of the modal shape analy-sis method. Thev can be used for engineers evaluating the practical dynamic beavior of the largescale elecltromechanical system,checking the existence of local reso,iance of the Stibsystem. and in-dentifying the wcakened positions of the rigidity of structure, In this paper the method of measuringand extracting the operational deflection shal1e of the electromecha nical system is given and theavailability of operational deflection shape is proved by analyzing the actual vibration of a large ex-haust fan system as an example.     

Pd Pattern Recognition Based on Linear Discriminant Analysis in GIS

According to the character of PD in GIS, the authors design four kinds of GIS defection models. The GIS gray intensity images are constructed based on mass specimens gathered by the ultra - high frequency and high speeds systems, Aiming at the PD characteristics and its defections, A PCA-FDA method is put forward based on PD images. The principal component analysis is employed to condense the dimension of PD images, then the optimal sets of statistically uncorrelated discriminant vectors are extracted, and the minimum distance classifier is constructed as classifier. The identified results show that this method can effectively elevated the discrimination of the four kinds of defects in GIS PD.     

Temporal-spatial Filtering in the Preprocessing of Clinical EEG Signals

EEG spot-recording for clinical patients in the bed is always advocated due to easing patients and making them comfortable. But EEG signals recorded in the ward exposed to various noisesand interference is less effective in the EEG analysis. Atemporal-spatial filter is designed for noise removing of clinical EEG signals, the first filtering is temporal filtering using band-pass filter, and the second filtering is spatial filtering with ICA-based spatial filter. Experimental results indicate that various noises and interferences, such as power interference, blinking, eyes movements, muscle moments, ECG artifacts, etc., are removed effectively, individually or simultaneously.     

Numerical Analysis and Optimization of a Small Vehicle Heat Exchanger

This paper analyzes the fluid flow and heat transfer of the heat exchanger, and obtainsd the distribution of fluid field, heat field and pressure field in heat exchanger. According the analysis result, some modify measure is adopted, such as decreasing the number of tube bundle, the size of baffle plate and increasing the diameter of exchange heat tube. In the new heat exchanger, the resistance decreased 32.3%, is 103.2 Pa and the temperature of the exit is 130 K. The new heat exchanger satisfies the requirement of exchanging heat. The study indicates that adopting the numerical simulation method could get temperature, pressure and fluid - velocity of anywhere of the heat exchanger, and understand effecfing of structure parameter on fluid flied and heat flied of the heat exchanger. Therefore, it provides a new method for optimization design of heat exchanger.