• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.125-134
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• 2004

By applying the test methods of "Protection Eyewear Standard (KS P 8147)", "Glasses Frame Standard (KS G 3306)" and "Lens Standard for Sunglasses (KS P 4404)", this study analyzed optical functions of sunglasses now being sold in a road shop (A shop), a fashion goods store (B shop), a shop of highway rest area (C shop) and an optical shop (D shop). When compared with sunglasses (UV transmittance rate 8.8%) of a road shop, UV Block effects of sunglasses (UV transmittance rate 0.7%) of an optical shop showed good results. In addition, the average surface resistance against abrasion for sunglasses which was sold at an optical shop was 1.4% that was much higher than that of sunglasses of a road shop(2.2%).

• Journal of the Korean Wood Science and Technology
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• v.45 no.2
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• pp.147-158
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• 2017

Among the energy consumption in building, the heating energy takes the largest part. Therefore, it is important to minimize the heat energy loss in building for the reduction of overall energy use in construction. The most important points for the minimization of energy loss in building are insulation and airtightness. Especially, in wood houses, airtightness is very important for energy saving as well as increase of durability. However, the researches on airtightness of wood buildings have been started recently and are very deficient especially in Korea. In this study, air leakage properties and airtightness performance were evaluated for light-frame wood houses built in Daejeon and Chungnam area. Total 7 houses were evaluated, among which four houses (Case 1 to Case 4) were in the construction stage before interior finish and the other three houses (Case 5 to Case 7) were after completion of construction work. The tests for airtightness were conducted by pressurization-depressurization method, and the factors included in the measurements includes air leakage rate at 50 Pa (CMH50), air change rate at 50 Pa (ACH50), equivalent leakage area (EqLA) and EqLA per floor area. As a result of this study, key air leakage points in wood houses were found to be the gaps between floor and wall, the holes for wiring and plumbing, the double glasses windows and the entrance doors. The average value of ACH50 for the houses after completion of construction work was $3.5h^{-1}$ that was similar to Europe standard ($3.0h^{-1}$). ACH50 was proportional to EqLA per floor area but inversely proportional to the internal volume, the net floor area and the area of window.