• Journal of Astronomy and Space Sciences
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• 제24권3호
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• pp.203-208
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• 2007

We report the distance modulus of nearby dwarf elliptical galaxy NGC 147 estimated from the Tip of Red-giant Branch (TRGB) method applying to the color-magnitude diagrams and luminosity functions in the near-infrared JHK bands. Apparent magnitudes of TRGBs in each band are obtained by applying Savitzky-Golay filter to the luminosity functions, and the theoretical absolute magnitudes are estimated from Yonsei-Yale isochrones. The derived values of distance modulus to NGC 147 are $(m-M)=23.69{\pm}0.12,\;23.78{\pm}0.17,\;and\;23.85{\pm}0.22\;for\;J,\;H,\;and\;K$ bands, respectively. Distance modulus in bolometric magnitude is also derived as $(m-M)=23.87{\pm}0.11$. We compare the derived values of the TRGB distance modulus to NGC 147 in the near-infrared bands with the previous results in other bands.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 추계학술대회 논문집
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• pp.81-85
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• 1992

Quality of cut is strongly dependent on the cutting pressure, so this relationship can be identified by pressure measuring system. In this paper, the experiments presented were performed with the devised pressure measuring system and the laser cutting of STS 304. Convergent type and convergent-divergent type nozzle were used for pressure variation of the distance between nozzle and workpiece. In laser cutting of STS 304, 1.0 kW CO $\_$2/ laser used. The convergent type nozzle(1.0 mm diameter) pressured above 3 kgf/cm $\^$2/, the MSD(Mach Shock Disk) created, which caused the the pressure variations of the distance between nozzle and workpiece. The maximum cutting pressure exists in accordance with the variation of distance. In spite of far distance the maximum cutting pressure is achieved by using the pressure measuring system. The higher cutting pressure beneath the workpiece the less quantity of dross and the kerf width. Since the higher cutting pressure helps to remove the quantity of dross and to stop the exothermic energy into the material. The optimum laser cutting parameter of STS 304(2.0 mm thickness) with the convergent type nozzle(1.0 mm diameter)is 0.75 mm and 2.5 mm distance between nozzle and workpiece, 4 kgf/cm $\^$2/ cutting pressure. In 3.0 mm thickness case, 1.5 mm and 2.25 mm distance is achieved for good quality.

• 한국CDE학회논문집
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• 제10권1호
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• pp.27-39
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• 2005

Implicit surfaces are geometric shapes which are defined by implicit functions and exist in three-dimensional space. Recently, implicit surfaces have received much attention in solid modeling applications because they are easy to represent the location of points and to use boolean operations. However, it is difficult to chart points on implicit surfaces for rendering. As efficient rendering method of implicit surfaces, the original Adaptively Sampled Distance Fields (ADFs) $method^{[1]}$ is to use sampled distance fields which subdivide the three dimensional space of implicit surfaces into many cells with high sampling rates in regions where the distance field contains fine detail and low sampling rates where the field varies smoothly. In this paper, in order to maintain the sharp features efficiently with small number of cells, an extended ADFs method is proposed, applying the Dual/Primal mesh optimization $method^{[2]}$ to the original ADFs method. The Dual/Primal mesh optimization method maintains sharp features, moving the vertices to tangent plane of implicit surfaces and reconstructing the vertices by applying a curvature-weighted factor. The proposed extended ADFs method is applied to several examples of implicit surfaces to evaluate the efficiency of the rendering performance.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.115-122
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• 1999

Because of their small mass, volume, solid state construction and long life, light-emitting diodes(LEDs) hold promises as a lighting source for intensive plant production system. Spectral characteristics and light intensity of LEDs were tested to investigate their feasibility as artificial lighting sources for growth and morphogenesis control in transplant production system. Blue, green, and red LEDs had a peak-emission wavelength at 442nm, 522nm, and 673nm, respectively. Their half width defined as the difference between upper and lower wavelength in the intensity equivalent to 50% of the maximum intensity showed 26nm, 41nm, and 74nm, respectively. Photosynthetic photon flux(PPE) at the distance of 9cm under the LEDs array was measured as $235{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for red, $109{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for green, and $75{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for blue LEDs. At the same distance, green LEDs had the illuminance of 13,0001x, nine to ten times higher than those of red and blue LEDs. Red, green, and blue LEDs at a distance of 9cm had the irradiance of $46W{\cdot}m^{-2},\;19W{\cdot}m^{-2},\;8W{\cdot}m^{-2}$, respectively. Light intensity of blue, green, and red LEDs increased linearly in proportion to the magnitude of the current applied to the operating circuit. Thus the light intensity of LEDs was controlled by the applied current in operating circuit.

• 한국수산과학회지
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• 제38권3호
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• pp.196-204
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• 2005

The horizontal and vertical distribution of yellowfin tuna, Thunnus albacares (Bonnaterre) and bigeye tuna, Tunnus obesus (Lowe) in relation to oceanic conditions such as thermal structure produced during El Nino/La Nina episodes were analyzed on the basis of data sets for the catches and efforts from the Korean tuna longline fishery and for the oceanographic observations from the NOAA during 1982-2002 in the tropical Pacific. The high density of fishing ground appeared in the western Pacific ($5^{\circ}N-5^{\circ}S,\;160^{\circ}E-180^{\circ}W$) for yellowfin tuna and in the eastern Pacific ($5^{\circ}N-15^{\circ}S,\;130^{\circ}W-100^{\circ}W$) for bigeye tuna. yellowfin and bigeye tunas were mainly distributed at the 110-250 m layer and 245-312 m layer, respectively, in the western Pacific. However, in the eastern Pacific, they were mostly caught at the 116-161 m and 205-276 m layer for yellowfin tuna and bigeye tuna, respectively. It can be suggested that bigeye tuna be distributed in the deepest layer among tunas and show a vertical size stratification. It was observed that during the El Nino events the main fishing ground of yellowfin tuna shifted from the western Pacific toward the eastern Pacific. In the eastern Pacific which showed a higher density of bigeye tuna, the vulnerability of bigeye tuna caught by deep longline increased during the El Nino events due to deepening of thermocline layer and a more intensively distribution of the fish schools in the lower layer of thermocline during the El Nino events.

• Geomechanics and Engineering
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• 제8권6호
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• pp.801-810
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• 2015

The ultimate pullout capacity under inclined dynamic loading is an important measure of the destruction degree of vertical screw piles (anchors) under dynamic actions. Based on the static and dynamic tests on two kinds of model screw piles, the ultimate bearing capacity was researched considering different distance-width ratio of blade (D/W) and preloading ratio. The results compared well with other experimental data available in the literature. This research reveals that D/W might determine the failure model of the piles (anchors), for example D/W = 3.14 or 5; a critical dynamic-static loading ratio (DSLR) existed in the experiments. The critical DSLR was reached under the conditions of 40%~60% preloading (D/W = 3.14) or 20%~40% preloading (D/W = 5), respectively.

• 한국화재소방학회논문지
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• 제27권3호
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• pp.1-7
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• 2013

전 세계적으로 기후변화 등의 원인으로 산림화재가 대형화되고 있다. 산림이 국토의 약 63.7 %를 차치하며, 산림에 인접해서 산업시설 등의 주요시설들이 많은 국내의 경우에는 산림화재가 대형재난으로 확산될 가능성이 매우 높다. 이에 본 연구에서는 수관화로 발달한 산림화재에서 화염의 복사열이 미치는 피해영향거리를 풍속의 변화에 따라 분석하였다. 또한, 영향거리를 분석하기 위하여 주변시설에 미칠 수 있는 복사열의 안전기준을 조사하였으며, 기준 복사열로 $5kW/m^2$와 $12.5kW/m^2$, $37.5kW/m^2$를 제시하였다. 산림화재 피해영향평가를 위해 FDS의 산림화재 확장 프로그램인 WFDS를 활용하였고, 해석조건으로 국내에 일반적으로 분포가 높은 산림조건에 대해 조사하여 이를 적용하였다. 그 결과는 풍속에 따른 복사열 최대영향거리로 제시하였다. 풍속 0~10 m/s에 있어서 풍속의 증가에 따라 영향거리도 증가하는 경향이 있으며, 풍속 8 m/s에서 영향거리가 최대가 되었다. 또한, 최대 영향거리는 수목 연료의 함수율 증가에 따라 크게 감소하는 것을 확인하였다. 본 연구는 산림화재로 인한 주변시설의 피해영향을 정량적으로 평가하는데 기여할 수 있다.

• 호남수학학술지
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• 제38권3호
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• pp.553-581
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• 2016

The purpose of this paper is to prove some fixed point theorems in a complete metric space equipped with a partial ordering using w-distances together with the aid of an altering functions and new functions of admissible type.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.139-141
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• 1989

The characteristics of the hollow cathode discharge were investigated. Temperature distribution of the hollow cathode was investigated and I-V curves of the hollow cathode discharge were obtained. In this paper variables are chamber pressure, Ar gas flow rate injected through the cathode tube and the gap distance between cathode and anode. The inter electrode electron temperature and density were measured by Langmuir probe.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.156-158
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• 2006

A super-regenerative receiver is designed and tested at 433 MHz ISM band, The designed receiver has the data rate of up to 200 kbps and a power consumption of 10 mW. We carried out the system performance test for the TX power of 0.1 mW and 1 m distance. The result of the bit-error rate test shows one bit error among the 4000 bits.