• Journal of Industrial Technology
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• v.31 no.A
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• pp.87-94
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• 2011

This paper is results of analyzing characteristics of landslides occurred in Wonju, Gangwondo, around July, 16 in 2006, caused by heavy rainfall and antecedent precipitation by two typhoons of Ewiniar and Bilis. The main causes of landslides were antecedent precipitation during July 8 to 15, resulting in weakening grounds by increasing the degree of saturation previously, and the heavy rainfall during July 15 to 16. Most of landslides in natural slopes were transitional failures occurred along the boundary between the residual weathered soil in shallow depth and the hard mother rock. From results of conclusive analyses regarding 28 sites in Wonju region where landslides occurred, the slope length of landslide, the slope width, and the slope area were less than 50m with 71% of frequency, 20m with 79% of frequency and $300m^2$ of 64% of frequency respectively. The average value of slope angle was $35^{\circ}$. The most probable direction of slope was found to be north because of topography and advancing direction of seasonal rain front.

• Journal of Magnetics
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• v.4 no.3
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• pp.73-75
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• 1999

By appliying an slternate pulsed magnetic field -generated by using a sequential ignition circuit and a magnet exciting circuit- with peak value of about 10 T to the rod type Nd based magnet Nd2Fe12.7Cr1.3B with length of 5 mm and diameter of 3.6 mm, the basic magnetic properties such as saturation magnetization, residual magnetization, coercivity, maximum energy products, magnetic anisotropy and anisotropic field are investigated with obtaining the major and minor J-H loops of the magnet. The increase in coercivity due to eddy currents in ac measurement of coercivity is calculated considering eddy current loss by analyzing a wave of generating magnetic field. The average coercivity calculated for the magnet is about 12.2 kOe, anisotropy magnetic field and anisotropic constant are measured as 60 kOe 2.43 Mj/$m^3$, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.1
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• pp.73-82
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• 2002

A small refrigeration system used in a water purifier was tested by employing propane/isobutane (R-290/R-6OOa) mixtures as an alternative refrigerant of R-12. The drop-in tests were performed by varying mass fraction of propane at 0.25, 0.5 and 0.75 with a change of both refrigerant charge amount and capillary tube length in order to find an optimum composition in aspect of performance and reliability of the system. As a result, the mixture of 50% propane-50% isobutane showed the best performance and reliability among them in a small refrigeration system. During steady state operations, both the COP and refrigeration capacity increased by 4% and 9%, respectively, as compared to the baseline R-12 system. In addition, the propane/isobutane (50/50) mixture system yielded advantages in the minimization of modification and redesigning of system components due to very similar saturation tempera- ture and pressure characteristics with R-12.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.86-90
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• 1992

We have studied the characteristics of n-and p-channel FETs with submicron channel length fabricated by twin-well process. Threshold voltage variation and potential distribution with channel ion implantation conditions and impurity profile of n-and p-channel region wee simulated using SUPREM-II and MINIMOS 4.0 simulater, P-channel FET had buried-channel in the depth of 0.15 $\mu\textrm{m}$ from surface by counter-doped boron ion implantation for threshold voltage adjustment. As a result of device measurement, we have obtained good drain saturation characteristics for 3.3 [V] opreation, minimized short channel effect with threshold voltage shift below 0.2[V], high punchthrough and breakdown voltage above 10[V] and low subthreshold value.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.895-900
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• 2000

In this paper, C-V characteristics based on the structure of GaAs MESFET’s has been proposed with wide range of applied voltages and temperatures. Small signal capacitance; gate-source and gate-drain capacitances are represented by analytical expressions which are classified into two different regions; linear and saturation regions with bias voltages. The expression contains two variables; the built-in voltage( $V_{vi}$ )and the depletion width(W). Submicron gate length MESFETs has been selected to prove the validity of the theoretical perdiction and shows good agreement with the experimental data over the wide range of applied voltages.

• Environmental Engineering Research
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• v.10 no.2
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• pp.71-78
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• 2005

A series of column experiments was conducted to develop a monitoring system for in-situ and realtime measurement of ozone transport in unsaturated porous media using a fiber optic sensor. The calibration of the fiber optic transflection dip probe (FOTDP) system was successfully carried out at various ozone concentrations using a column with length of 30 cm and diameter of 5 cm packed with glass beads, which don't react with gaseous ozone. The breakthrough curves (BTCs) of ozone were obtained by converting the normalized intensity into ozone concentration. The FOTDP system worked well for in-situ monitoring of gas phase ozone at various water saturations and in presence of soil organic matter (SOM). However, the FOTDP system did not measure the ozone concentration at more than 70% water saturation.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.430-430
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• 2010

MICC 방법으로 제작된 TFT는 large grain과 그에 따른 grain boundary의 감소로 인하여여, 소자의 전기적 특성을 좋게 할 수 있다. 본 연구에서는 bi-layer channel의 large grain size TFT를 제작하여 소자의 전기적 특성을 비교하였다. Channel의 width / length의 크기는 각 각의 경우 $7/5{\times}2$, $10/5{\times}2$, $15/5{\times}2$ (${\mu}m$)로 하였다. 소자의 성능 측정 결과 Field-effect mobility의 경우에는 channel width가 증가할 수록 감소하는 경향성을 나타내었으며, Threshold voltage의 경우에는 조금 감소하는 경향성은 있었으나 변화의 폭이 매우 작았다. Output characteristics 의 경우에는 모든 set에서 좋은 saturation 특성을 보였다. 이것은 current croding이 없었다는 것을 의미하는데, 큰 grain size로 인한 효과로 해석 할 수 있다. 본 연구에서는 bi-layer channel에서 corner effect에 중점을 두어 소자의 전기적 특성 변화에 대하여 논하였다.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.131-139
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• 2000

The effects of the simulated acid rain on the growth response and water status of Glycine soja was observed in 2 months-old seedlings. The seedlings were treated with acid rain(pH 3.5), three times per week. Glycine soja showed significant reduction in the total length, total weight, dry weight, water contents and top/root ratio after treatment of simulated acid rain(pH 3.5) for 56 days. The growth of shoot was more susceptible to acid rain than that of roots. On the contray, Number of lateral roots, water saturation deficit and epidermis transpiration was higher than that of control(pH 5.6) after 56 days treatment of simulated acid rain.

• Journal of Korea Soil Environment Society
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• v.4 no.3
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• pp.17-24
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• 1999

The effects of hydrophobic chain length and its structure of nonionic surfactants on surfactant adsorption and contaminated diesel removal were studied in kaolin soil. Hydrocarbon chain length and double bond in hydrophobic tail group of nonionic surfactants affected surfactant adsorption and diesel removal efficiency from kaolin soil. The degrees of surfactant adsorption and diesel removal were closely related each other. Among nonionic surfactants we studied, surfactants with shorter hydrophobic chain length and higher HLB value showed lower degree of adsorption and higher efficiency of diesel removal. The existence of unsaturated carbons in the structure of hydrophobic chain enhanced diesel removal by reducing surfactant adsorption to kaolin soil. The best diesel removal was obtained after adsorption saturation was reached. If surfactant concentration was higher than a critical value, diesel removal was reduced probably because of precipitation. liquid crystal formation, or coacervation of surfactants at high concentration.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.5
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• pp.367-372
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• 2015

In this study, locality of scleroderma was detected. Diagnostic method is difficult for scleroderma (skin curing; Scleroderma), and it is done by comparing the images of the normal subjects to the scleroderma patients, after performing monochrome processing. The saturation, brightness, and contrast are adjusted, and they were converted by using the process of Well Filter. As a result, the images were able to be used to clearly distinguish the symptoms of scleroderma. In addition, in a video of a healthy person, the line of sight of the observation given the image of scleroderma patients above sea level of height as $0^{\circ}$ is to implement the closing process to the rear Well Filter even only in so that the horizontal plane, and out at intervals of graph the amplitude difference of the video have I asked. The diagnostic criteria were determined for the healthy subjects and the scleroderma patients.