CAM CORRELATION ANALYSIS USING ACOUSTIC DISCHARGE MEASUREMENT
The low head hydro power plant in Wettingen, Switzerland, is in operation since 1933 and no effective cam optimization has been carried out up to now. The goal of the measuring campaign was to provide data enabling an economic study for a retrofit and upgrade project of the plant and the measurement of the efficiency improvement of turbines after refurbishment. The contribution discusses cam tests using the acoustic transit time method in the intake for discharge measurements. A cam correlation analysis and an efficiency test of the installed Kaplan turbines were performed as a first measurement campaign showing the actual status. While one turbine operated at optimum cam, the other two turbines operated off-cam. After rehabilitation works, based on the recommendations of the first measurements, a second measurement campaign was performed. The results showed the expected efficiency increase due to overhaul of the regulating mechanics (connection between the piston stroke in the machine hall and the regulating ring / guide vane stem at the turbine) of the governor. With the set of data from the second measurement campaign an optimization study for the operation of the three Kaplan units were conducted. Especially the transition zone from one to two and from two to three machine operation could be optimized due to the knowledge of the individual efficiency curves.
DISCHARGE MEASUREMENTS AT LA RANCE TIDAL POWER PLANT USING CURRENT METERS METHOD
La Rance was the first tidal power plant worldwide with a capacity of 240 MW supplied by 24 bulb units working in both flow directions. Many tests had been undertaken in laboratory and on the prototype of Saint-Malo, but no real commissioning tests had been carried out until now. Measuring discharge at La Rance is indeed complex because of a very low and changing head from 2 m to 11 m depending on the tides, large gate bays of 8.7 m on 8.8 m, and high flow rate variations from 75 m 3 /s to 280 m 3 /s. It was decided to use current meters on a moving frame in the bulkhead slot for flow rate measurement. Further challenge was to maintain an almost constant head of 4 m during data acquisition. Full exploration of the velocity field was completed in both directions in 6 vertical positions. Additionally cam tests were performed, using index measurement with the frame in the middle position.
Automatic classification of TV news articles based on telop character recognition
The purpose of this study is to develop a multimedia database system for TV news video data. TV news video data consist of speech, characters and images. In this study, telop characters are recognized and given to the news articles as indices for classification. At first, telop frames which include telop characters are detected and then the telop characters are extracted and recognized. Through morphological analysis of the recognized telop characters, keywords are extracted which consist of more than two characters. Their keywords are used as indices to classify the TV news articles. We carried out experiments for 30 days of NHK 5 minutes news and obtained 95.4% telop character extraction rate, 81.4% character recognition rate and 83.8% article classification rate. We improved the article classification rate by 43.4% through character recognition improvement from 44.1% to 81.4%.