In this study, we analyzed the radiant heat performance of ballast fin when the aspect ratio of the fin of ballast was changed. The minimum size of the mesh was 0.02 mm, and the grid number was about more than 11 thousand. In order to analyze the radiant heat performance of ballast fin, the aspect ratio of fin was 1.00(2 mm:2 mm), 1.80(1.5 mm:2.7 mm), and 0.56(2.7 mm:1.5 mm) respectively; that the heat transfer area was constantly 0.4 mm 2 . The numerical condition was that heat flux was constantly 1×10 5 W/m 2 , and measuring times were 0.1 second, 0.2 second, 0.5 second, 2 seconds, 5 seconds and 10 seconds respectively. The temperature values of fin at the 1.00 and 1.80 of aspect ratios were extremely large when heat flux time was 10 seconds. As a result, the maximum value of radiant heat performance of ballast fin appeared to the aspect ratio of 1.80.

This study was conducted to research how UCD(Ultra Constant Discharge) lamp lighting affects plant cultivation. To get the results within a short time, lettuce seedling was selected as a plant and nutrient hydroponic beds were used in a dark room for 100% artificial lighting. Two beds were installed for same distance lighting condition with UCD lamp and Hi-pressure Sodium lamp each and another two beds were installed for same light intensity condition with each type of lamp. After 15 days of cultivation, for both conditions, the yields under UCD lamp were weighed more than that under Hi-pressure Sodium lamp. The result can be analyzed that the spectrum of UCD lamp having near sunlight characteristic is much superior to that of Hi-pressure Sodium lamp having a line spectrum characteristic on yellow and red wavelengths for plant cultivation.