• 한국제4기학회:학술대회논문집
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• 한국제4기학회 2007년도 춘계학술대회
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• pp.3-3
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• 2007

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1998년도 학술발표회 논문집
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• pp.419-424
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• 1998

• 한국해양공학회지
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• 제8권1호
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• pp.62-70
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• 1994

In order to estimate the detection range of a active SONAR system, the SONAR equation is commonly used. In this paper, an algorithm to calculate detection range in active SONAR system as function of SONAR depth and target depth is presented. For given SONAR parameters and environment, the transmission loss and background level are found, signal excess is computed. Using log-normal distribution, signal excess is converted to detection probability at each range. Then, the detection range is obtained by integrating the detection probability as function of range for each depth. The proposed algorithm have been applied to the case of omni-directional source with center frequency 30Hz for summer and winter sound profiles. It is found that the optimal search depth is the source depth since the detection range increase at source depth where the signal excess is maximized.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.439-443
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• 2006

Soil properties of Quercus variabilis forest on Youngha valley at Mt. Worak National Park were studied as a part of Korea National Long-Term Ecological Research. Soil sampling was carried out along the 50 cm soil depth with 10cm intervals at every quarter from May 2005 through July 2006. Fresh soil was used for $NH_4{^+}-N,\;NO_3{^-}-N$, and soil water content determination. Remaining soils were air dried in the shade, and then used for determination of soil pH, T-N, T-P and exchangeable cation. Average soil organic matter in top soil was $8.5{\pm}1.2%$ and decreased with soil depth. Bulk density of top soil was $0.82{\pm}0.07g/cm^3 $and increased with soil depth. Soil organic matter and bulk density showed a negative linear correlation ($R^2=0.8464$). Soil pH in top soil and subsoil was similar. T-N, $NH_4{^+}-N,\;NO_3{^-}-N$ and T-P in top soil were $1.9{\pm}0.5mg/g,\;7.3{\pm}1.0mg/kg,\;2.0{\pm}0.4mg/kg\;and\;0.2{\pm}0.05mg/g$, respectively. $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in top soil were $84.6{\pm}24.4,\;408.8{\pm}137.8\;and\;93.4{\pm}23.0mg/kg$, respectively. They decreased with soil depth. Amounts of organic matter, T-N, $NH_4{^+}-N,\;NO_3{^-}-N$, T-P, $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in 50 cm soil depth were 250.9, 3.45, 0.025, 0.003, 0.639, 0.181, 0.845 and 0.302 ton $ha^{-1}\;50cm-depth^{-1}$, respectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.35-38
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• 1990

Depths of the vertical cracks in the concrete were determined by the time of flight of the ultrasonic waves. The ultrasonic waves are diffracted at the crack tip, and the arrival time of ultrasonic waves are dependent on the crack depth and speration distance between transmitting and receiving ultrasonic transducers. The vertical cracks with 0.2-2mm width and 10-100mm depth were examined by multi-layered ultrasonic transducers. It was found that the time of flight of ultrasonic waves were proportional to the depth of vertical cracks. The depth of vertical cracks in the range of 20-100mm depth could be determined by the transient time of the diffracted ultrasonic waves

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.50-54
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• 2002

Penetration depth of Nb electrodes in $Nb/A1O_x/Nb$ Josephson junctions has been measured by resistive method. For a given applied field, the total flux through the junction is temperature dependent because the penetration depth of Nb electrode varies with temperature. If the total flux equals an integral multiple of the flux quantum at certain temperatures, resistive peaks appear at those temperatures. The penetration depth of Nb can be determined by applying the above condition, The temperature dependence of penetration depth was found to be well described by the two-fluid model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.593-595
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• 1995

X-Ray Diffraction method that gives direct information about the deformation of crystal lattice is used for the determination of profiles of the residual stress along the depth of heavily boron doped silicon. The residual stress distribution is obtained by XRD method as measuring the deformation of the front surface of the $p^+$ silicon layer fabricated through different etch time. It is determined that the compressive residual stress exists in the most region except the font surface.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.603-608
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• 2008

A simple equation to find a optimum speed of desiccant rotor is presented in this theoretical study. Usually the determination of optimum speed of desiccant rotor requires tedious and lengthy procedures by solving governing differential equations with many complicated parameters. The determining equation of optimal rotating speed is derivated from governing differential equations with three linearization assumptions, which simplify temperature profile linear along the desiccant rotor depth, psychrometric chart within a proper range, and relative humidity-sorption capacity relation. This study shows that the dominant parameters of optimal rotating speed of desiccant rotor are NTU, flow velocity, desiccant rotor depth, and temperature different between dehumidification and regeneration. The comparison shows the good agreement between complicated calculation results and simple theoretical equation prediction.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.49-56
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• 1999

Crustal velocity model is very important to determine the hypocenters of the local earthquakes because the real crust is more complex and heterogeneous than simple homogeneous layerd model. But the exact crust model in and around Kyeongsang basin area is not fixed till now. To solve this problem Joint Hypocenter Determination(JHD) method is applied to the 133 local earthquakes that is recorded at KIGAM local network from Dec. 14 1994. to May 14, 1998. According to the comparision of earthquake locations and depths for the conventional procedure and JHD relocation procedure each locations is very similar but depth distributions are different. An initial depth distribution derived from the conventional methods is irregular and does not show the general trends. JHD relocations reduce scatter and define a dipping plane which is parallel to and apart 15km north from Ulsan fault.

• 한국전기전자재료학회논문지
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• 제17권6호
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• pp.668-672
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• 2004

Upon Debye's dielectric relaxation theory, we tried simple determination method of trap level in organic EL materials. From dielectric measurements in the 20 Hz - 1 MHz frequency range and in the 150 K - 320K temperature range, the depth of traps in Alq$_3$ filled with remaining electrons was determinated. Comparing to other determination techniques like TSL, or TL, the apparatus all we need is just simple LCR meter, thermometer and cooling method(liquid nitrogen). The mean activation energy is about 0.20 eV. It is in good agreement with previous determinations by other techniques like TSL. This results consolidate the validity of Burrow's transport mechanism model. Further intensified experiment with UV light on the dielectric absorption(Photodipolair effect) was nevertheless disturbed by the photoconductivity component.