• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.10
• /
• pp.143-148
• /
• 2010

Recently, the KEPCO is constructing the PQMS(Power Quality Monitoring System) each of the distribution line and will establish the voltage sag standard based on the long time measurement data of PQMS. The voltage sag prospect is difficult for the power system manager, however, the voltage sag forecasted is very important because the damage effect of the voltage sag is very broad. This paper describes the prospect formula of the voltage sag magnitude in the PCC(Point Common Coupling) by the starting current when the high capacity equipment is connected with the distribution line. To achieve this, this paper has proposed the sag prospect formula revision of KEPCO for the reliability improvement and the proposed formula has been applied the voltage sag real case to inspect the calculation procedure and reliability.

• International Journal of Highway Engineering
• /
• v.17 no.4
• /
• pp.63-68
• /
• 2015

PURPOSES : A study on the efforts to minimize the road traffic noise has been underway. An attempt has been made to measure the noise level using a noise map; however, the attempt is limited to certain areas only. In general, a noise barrier is employed to prevent road traffic noise; however, unplanned noise barriers developed without considering the surrounding environment, including excessively high walls, cause problems such as infringement on prospect right. Noise ceiling at daytime in Korea is 68 dB(A), which is relatively higher than in other countries. METHODS: The noise barrier used mainly for road noise reduction was analyzed to estimate the optimal height. Related variables such as road width, the height of the upper part, distance to the building, and angle (for instance, $30^{\circ}$). RESULTS : A formula to calculate the optical height of the noise barrier, considering the road environment (i.e., parameters such as road width and distance to building), was developed in this study in an attempt to mitigate the noise generated from the road. CONCLUSIONS : The formula to calculate the noise barrier is expected to lead to cost saving, accurate installation of barriers, and protection of the right of prospect.

• Journal of the Korean Society of Costume
• /
• v.51 no.2
• /
• pp.181-192
• /
• 2001

Men study the nature in two ways. Scientists and mathematicians inquire a branch of those two ways. Mathematical formulations are the tools and the expressions of their nature. Meanwhile, the other branch, the art, alms for different inquiry. Instead of formulating the nature, the artists create their masterpieces from their ultimate source, the Mother Nature. For thousands of years these two branches have grown together, influencing each others work. Some mathematicians find that formulation, are not enough to fully express the beauty of nature. It is believed that such a simple expression, formula, easily omits the careful details of nature. The nature is simply too chaotic to be shaped with a formula. Of those mathematicians, Mandelbrot, one of the first to realize this matter, introduced the world of fractal geometry. Fractals give new possibilities. It allows us not to limit ourselves to linear prospect, rather a whole new view of this chaotic beauty of the nature. A popular practice to understand fractals is in costume design. The artistic characteristic and organization mechanism is appalled to costumes. Meanwhile, another practice, rather aggressive, is using computer to create an image of fractals. This image is then used for motives to generate artistic expressions. Computer and paper ironing technique is used for fashion illustration in this research. The works were synthesized arid transformed from computer programs. To add more traditional painting touch to this work, Paper ironing technique was used. Since the of effect of this technique is so random, irregular, and unordered, it corresponds to fractal consideration. This thesis asserts an another prospect to fractal as a structural way of describing nature ailed fashion illustration, rather than restricting it to only mathematical theory.