• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2004.11a
• /
• pp.367-371
• /
• 2004

The purpose of this research is furnishing of basic material for acoustic planning hereafter, after understanding the acoustic merits and demerits through measuring and analyzing on room acoustic of small performance hall. As the result of the measurement, those physical evaluation indexes such as SPL, RT, EDT, $D_{50}$, $C_{80}$, RASTI have being kept the satisfiable acoustic condition for the service of performance hall. Therefore, as small performance hall is regarded as equipped with sufficient volume of sound, reverberatory feeling and diffusive feeling, it judges as an excellent performance place, also it is considered that it could be utilized as a useful material when design so similar performance hall, hereafter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1992.11a
• /
• pp.110-113
• /
• 1992

This paper presents the results on experiments of relative dielectric constant dielectric loss, conductivity change and breakdown voltage of the L.D.P.E. mixed with Dodecyl Alcohol. The frequency range is 0.1 - 20 MHz and temperature, 20 - 80 $^{\circ}C$. Dielectric properties were similar to those of nonpolar polymers. Until $60^{\circ}C$ the conductivity value of compound was decreased with temperature increasment. And, its breakdown voltage was measured higher, about 3-4KV, than that of the pure L.D.P.E.. Also the amount of remnants of DA in the compounds were considered.

• Korean Institute of Interior Design Journal
• /
• no.23
• /
• pp.19-25
• /
• 2000

This study aims by analysing the interior design elements trends of current medium size office buildings in Seoul. The analysing objects are ceiling, floor, wall, and illumination plan of current office buildings. Analysing tools are finishing material and color of each part. Analysing areas are lobby area, deskwork area, conference area, welfare area, public area(rest room, corridor, stair). The interior design elements of lobby shows a lots of different features then the other areas in ceiling, floor, and wall design. Such difference appears at finishing material especially, and the coloring is more splendorous then the other areas. Desk work area and conference area have similar characteristics in finishing materiors and colors, and they usually follow the needs of function. Walfare area shows more splendorous feature then deskwork and conference area, and designed by various materials and colors. Public area also shows very active design concept then past times.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.6
• /
• pp.799-804
• /
• 2011

CFRP(Carbon Fiber Reinforced Plastics) has been used many industries aerospace, automobile, medical device and building material industries, etc. Because it is lighter than other metals and has good properties, such as rigidity, strength and wear. CFRP may be cured integrity. However, it needs postprocessing similar to drilling or endmilling for shape cutting and combination of various material. In this paper, tool dynamometer and accelerometer used to signal analysis for machining properties under various cutting conditions and tool shape changes. In addition, microscope used to verify the machined CFRP surface. As the results, it was found that the cutting force and the vibration were decreased in the increasing of cutting edge (2-flute < 4-flute < composite tool), and the good machined surface can be obtained in this experiments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.308-311
• /
• 2001

Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure( $PO_3$ ). It is found out that these phases show similar $T_{sub}$ and $PO_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.05c
• /
• pp.148-151
• /
• 2002

In order to prevent the failures of underground distribution power cables we need to measure insulation condition in the field. Until now we used DC high voltage as a power source for the cable diagnosis but it was not proper method to the XLPE insulation cables because DC high voltage can affect sound insulation and can't diagnose exactly insulation degradation. For these reasons we imported isothermal relaxation current measurement system called by KDA-1 from germany but it's reliability did not proved in our URD cables. DC voltage decay measurement system was developed by domestic company but they don't have field experience. In this paper we tried to prove reliability of these two systems in the field. Through the field diagnosis and Ac breakdown test the two systems showed similar results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.69-72
• /
• 2001

A novel water-turbine, Katamax, for micro hydropower generator is proposed, which has reasonable efficiency even in two meters of water head. The basic concept of Katamax is similar to that of waterwheel except that Katamax has two axis on which the blades rotate, where general waterwheel has only one. Brief structure and principles of Katamax are explained and analysis for efficiency of each module are provided. The result of the prototype product of Katamax is briefly explained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.201-204
• /
• 2001

In this paper, for modeling of electrical characteristics in Poly Silicon Thin Film Transistors with process parameters set up optimum values, So, the I-V characteristics of poly silicon TFT parameters are examined and simulated in terms of the variations in process parameter. And these results compared and analyzed simulation values with examination value. The simulation program for characteristic analysis used SUPREM IV for processing, Matlab for modeling by mathematics, and SPICE for electric characteristic of devices. Input parameter for simulation characteristics is like condition of device process sequence, these electric characteristic of $I_D-V_D$ $I_D-V_G$, variations of grain size. The Gate oxide thickness of poly silicon are showed similar results between real device characteristics and simulation characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.327-328
• /
• 2005

Bi-system thin films are prepared by ion beam sputtering technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure($PO_3$). It is found out that these phases show similar $T_{sub}$ and $PO_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1994.11a
• /
• pp.202-205
• /
• 1994

There is a close relation between electrical treeing and internal partial discharges in solid dielectrics. In this paper, the characteristics of electrical treeing and partial discharge in solid dielectrics are investigated. We carried out the measurements of electrical treeing and PD(partial discharge) characteristics. From the experimental results, we found out that maximum PD magnitude increased linearly with time at first stage, thereafter increased remarkably. These tendencies are very similar to the characteristics of tree growth with time.