• 한국환경생태학회지
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• 제15권1호
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• pp.79-91
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• 2001

본 연구의 목적은 대표적인 6개 국립공원에 대하여 자연 및 문화자원의 이용가치와 비이용가치를 이선선택형가상가치평가법을 이용하여 측정하는 것이다. 측정결과 이용가치의 경우높게는 17,208원/1인(설악산국립공원)에서 낮게는 5,758원/1인(태안해안국립공원)의 범주로 나타났다. 또한 비이용가치의 경우 높게는 16,198원/1인(북한산국립공원)에서 낮게는 12,756원/1인(한려해상국립공원)의 범주로 나타났다. 본 연구결과는 국립공원이 현재의 입장료(1,000원/1인)와 국립공원의 유지관리비(3.700원/1인)를 능가하는 상당한 정도의 이용가치와 비이용가치를 창출하고 있다는 사실을 지적해준다. 따라서 국민의 경계적 편익을 유지하기 위해서 정부는 국립공원의 유지. 관리비용을 계속 지원해야만 할 것이다.

• The Korean Journal of Ecology
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• 제20권5호
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• pp.303-313
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• 1997

A new evaluation technique, i.e. multicriterion matrix technique, on the vegetation assessment was proposed and compared with several techniques having been previously used in the environmental impact assessment. Four criterias and 10 subcriterias were selected for two evaluation indices such as vegetation naturalness value and vegetation class. These criterias were characterized by syntaxonomical informations of hemeroby concept and potential vegetation, hierarchical system between criterias, and ordinal scale of vegetation naturalness valuse. Vegetation naturalness values were classified into 11 ordinal levels and condensed to five vegetation classes for facilitating practical use. In the example study two sites were compared by using two indices. This technique could have useful applications for ssessment of regional vegetation. A vegetation map of naturalness described by combination of two indices was proposed in order to illustrate regional vegetation naturalness.

• 전자공학회논문지A
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• 제31A권10호
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• pp.94-100
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• 1994

By using the RAPHAEL 3D inductance calculation program RI3, the PGA package inductance values of INTEL i486 microprocessor have been extracted. The lead frame layouts are drawn using the mentor Boardstation and the output files are converted into the RI3 program input format of RAPHAEL. The power and ground planes of the PGA package are modeled y grid-line structures of single bars. The capacitance valuse of signal lines have been clalculated by using the RAPHAEL 2D/3D capacitance extraction program. The extraced L, C, R values have been converted into the SPICE netlist formats with lumped circuit model for future use in the signal ingegrity analysis.

• 한국표면공학회지
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• 제22권3호
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• pp.118-127
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• 1989

The rate of electrodeposition Zinc-nickel alloy on to electrolytic ione in sulface solution both under an inter and air atmospherss has studied by use of a rotating disc geometry. The kinetics shows 1st order reaction, and the rate constants are proportional to the square root of rpm, however, they are less than the valuse suggested by Levich. The rate constants of zinc deposition approach the total mass transfer rate constants with increasing potential and deviate with increasing rotaing speed, but those of nickel deposition are constant. Below $40^{\circ}C$ the activation engrgies of zinc deposition and nikel deposition were 4.4Kcal/mol and 6.3Kcal/mol respectively. There results show that overall reaction rate of zinc-nickel plaeting is controlled by mixed reaction and zinc deposotion is more affected by mass transfer reaction than nickel. The current density for the zinc-nickel plating was less in an air atmosphere than in a nitrogen atmosphere. The cathode efficiency increased with decreasing cathode rotating speeds, potentials, and increasing temperatures. Zzinc-nickel platings are more improved in microhardnss than zinc platings.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 춘계학술발표대회 개요집
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• pp.228-231
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• 2001

Elastic-plastic fracture toughness $J_{1c}$ can be used as an effective design criterion in elastic plastic fracture mechanics. Most of these systems are operated at high temperature and $J_{1c}$ values are affected by temperature. therefore, the $J_{1c}$ valuse at high temperature must be determined for use of integrity evaluation and designing of such systems. Elastic-plastic fracture toughness $J_{1c}$ tests were performed on SA516 carbon steel plate and test results were analyzed according to ASTM E 813-8, ASTM 1813-89. Safety and integrity are required for reactor pressure vessels vecause pthey are operated in high temperature. there are single specimen method, which used as evaluation of safety and integrity for reactor pressure vessels. In this study, elastic-plastic fracture toughness$(J_{1c})$ and $J-\Delta{a}$ of SA 516/70 steel used as reactor pressure vessel steel are measured and evaluated at room Temperature, $150^{\circ}C$, $250^{\circ}C$ and $370^{\circ}C$ according to unloading compliance method.

• 한국농공학회지
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• 제18권2호
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• pp.4089-4095
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• 1976

The safety of shore structure including the sea dipe is largely affected by typhoon. Accordingly it is desirable to analize the typhoon and determine the wind direction and velocity for use in planning and design of the structure. This method was adopted for the design of the Yong San Gang Estuary Dam. A comparative study of the results of typhoon analysis with the meteorological data obtained through actual observation is summarized as follows; (1) 62% of the typhoons occur during May to June in a year, and 62% of the typhoons which have an influence on the Korean peninsula, especially the proposed estuary dam fsite, proceed eastward through the zone in lat. 36$^{\circ}$-37$^{\circ}$N. Such typhoons occur two to three times a year on the average. (2) Data on typhoon "SARL" were used as a model case in designing the estuary dam, where it was proved that a southwesterly wind had a maximum velocity of 30m/sec in case r=150km, ${\alpha}$=120$^{\circ}$. Within the range of 22$^{\circ}$30'on the right and left side of the fetch line of the estuary dam, the wind direction varied SSW\longrightarrowSW\longrightarrowWSW, and the wind velocity varied 29m/sec\longrightarrow30m/sec\longrightarrow125m/sec. Such phenomemum lasted for five hours. (3) An analysis of data obtained during 44 years at Mok Po Meteorological Station shows that a wind with a velocity of some 25m/sec occurred twelve times in the S-direction and two times in the SW-direction, while that with a velocity of 30m/sec occurred three times in the S-direction, three times in the SSW-direction and one time in the SW-direction. The wind which had an influence on the estuary dam had a direction of SSW\longrightarrowSW\longrightarrowWSW and a velocity of min. 30m/sec. Actually, a wind with a max. velocity of 31.3m/sec occurred in the SSW-direction on March 15 and 16, 1956 where the mean velocity during two hours was 28m/sec and that during four hours was 24.6m/sec. (4) The data obtained through actual observation show that when the velocity is low, the wind with a fixed direction lasts long, and when the velocity is high, it is short-lived. It is difficult to determine the velocity of a wind which blows in a fixed direction for consecutive two or four hours. Therefore, the values obtained through typhoon analysis are larger that those obtained through actual observation, and hence, it is resonable to use the analyzed valuse for design of the estuary dam and shore structures. (5) The greatest effect was had on the estuary dam when typhoon was proceeding at a velocity of 29.71m/sec in the direction of ${\alpha}$=120$^{\circ}$(SW) at a point of R=150km from the center of the typhoon.

• 한국추진공학회지
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• 제15권4호
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• pp.85-93
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• 2011

아크 채널 모델을 이용하여 플라즈마 온도를 매개로 플라즈마 입력전력과 전류 조건에 따른 간극 반지름(R) 및 간극팩 묶음 길이(L) 변수 계산이 가능한 해석해를 유도하고 이를 이용하여 300 A 전류조건에서 0.4 MW 급 분절형 아크 플라즈마 토치에 대한 해석적 설계 변수 해석을 수행하였다. 해석 결과, R��${\leq}$ 7.5 mm, L ${\leq}$ 1.25 m 인 범위에 대해, L이 길어지거나 R이 작아질 때, 플라즈마 온도는 비례하여 증가하는 경향을 가지고 있음을 알 수 있었으며, 그 이상의 범위에서는 증가하다 감소하는 비선형 현상이 존재하여 주어진 전류 및 전력조건에서 아크 플라즈마의 형성이 불가능하거나 불안정할 것으로 예측되었다. 이와 같은 결과를 바탕으로 입력전류가 300 A 일 때, 아크 플라즈마 온도를 안정적으로 구현할 수 있을 것이라 여겨지는 0.4 MW 급 분절형 아크 플라즈마 토치의 간극 반지름 R 및 간극팩 묶음 길이 L의 설계범위를 각각 5.5 mm ${\leq}$ R ${\leq}$ 7.5 mm, 0.25 m ${\leq}$ L ${\leq}$ 0.5 m 범위로 제안하였다.