• Proceedings of the Materials Research Society of Korea Conference
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• 2008.05a
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• pp.24.1-24.1
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• 2008

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.989-994
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• 2000

• Journal of Korea Water Resources Association
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• v.30 no.5
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• pp.423-430
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• 1997

It is one of the most important factors to determine the effective rainfall for estimation of flood hydrograph in design schedule. SCS curve number (CN) method has been frequently used to estimate the effective rainfall of synthesized design flood hydrograph for hydraulic structures. But, it should be cautious to apply SCS-CN originally developed in U.S.A to watersheds in Korea, because characteristics of watersheds in Korea and cropping patterns especially like a paddy land cultivation are quite different from those in USA. New CN method has been introduced. Maximum storage capacity which was herein defined as Umax can be calibrated from the streamflow data and converted to new CN-I of direst condition of soil moisture in the given watershed. Effective rainfall for design flood hydrograph can be estimated by the curve number developed in the watersheds in Korea.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.919-924
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• 1996

Crystal structure of two inclusion compounds Cd(pn)Ni(CN)4·0.25G (G=toluene and p-xylene, pn=1,2-diaminopropane) have been determined from single-crystal X-ray diffraction data; toluene clathrate: monoclinic P21/n, a=13.838(6), b=26.893(5), c= 7.543(5) Å, γ=90.92(3)°, Z=4, R=0.0616; p-xylene clathrate: monoclinic P21/n, a=13.895(2), b=26.900(3), c=7.613(1) Å, γ=91.06(1)°, Z=4, R=0.0486. The host structures determined for toluene- and pxylene-guest clathrates are substantially identical to the U-type structures observed for the straight chain aliphatic-guest clathrates. However, the alternating arrangement of occupied channels with the guest molecules and vacant channels appears in the host structure. The non-centrosymmetric toluene molecules are distributed about the inversion center to give an image like p-xylene molecule. The guests, toluene and p-xylene, prefer the U-type channel, favoring the interaction between the π-electrons of the aromatic ring and the pn-amino groups to hold the aromatic ring vertical to the cyanometallate meshes.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2410-2412
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• 2005

In this study, two types of PS substrate were fabricated for sensing of chemical and biological substances. For sensing of the humidity and chemical analyzes such as $CH_3OH$ or $C_2H_5OH$, PS layers are prepared by photoelectrochemical etching of silicon wafer in aqueous hydrofluoric acid solution. To evaluate their sensitivity, we measured the resistance variation of the PS diaphragm. As the amplitude of applied voltage increases from 2 to 6Vpp at constant frequency of 5kHz, the resistance variation for humidity sensor rises from 376.3 to $784.8{\Omega}$/%RH. And the sensitivities for $CH_3OH$ and $C_2H_5OH$ were 0.068 uA/% and 0.212 uA/%, respectively. For biological sensing application, amperometric urea sensors were fabricated based on porous silicon(PS), and planar silicon(PLS) electrode substrates by the electrochemical methods. Pt thin film was sputtered on these substrates which were previously formed by electrochemical anodization. Poly (3-methylthiophene) (P3MT) were used for electron transfer matrix between urease(Urs) and the electrode phase, and Urs also was by electrochemically immobilized. Effective working area of these electrodes was determined for the first time by using $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ redox couple in which nearly reversible cyclic voltammograms were obtained. The $i_p$ vs $v^{1/2}$ plots show that effective working electrode area of the PS-based Pt thin film electrode was 1.6 times larger than the PLS-based one and we can readily expect the enlarged surface area of PS electrode would result in increased sensitivity by ca. 1.6 times. Actually, amperometric sensitivity of the Urs/P3MT/Pt/PS electrode was ca 0.91uA/$mM{\cdot}cm^2$, and that of the Urs/P3MT/Pt/PLS electrode was ca. 0.91uA/$mM{\cdot}cm^2$ in a linear range of 1mmol/L to 100mmol/L urea concentrations

• Publications of The Korean Astronomical Society
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• v.7 no.1
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• pp.167-188
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• 1992

서울대 천문학과(SNU)의 Washington 측광계를 사용하여 관측한 자료와 ADC (Astronomical Data Center)의 자료를 분석함으로써 SNU Washington 측광계를 표준화 시켰다. SNU Washington 측광계중에서 C필터에 나타나는 적색광 누출은 V필터와의 결합을 통해 보정했으며, 그 최대값은 K0형에서 약 $0^{m}.14$까지 이른다. ADC의 자료분석 결과 G. K형 별들에 대해 중원소 측광지수와 중원소함량과 서로 잘 일치함을 알 수 있었고. 주계열성의 경우 온도 측광지수와 온도와는 좋은 관계를 보임을 알 수 있었다. 또한 ($M-T_2$)과 ($M-T_1$) 평면상에서는 중원소함량과 광도계급에 무관한 좋은 온도관계를 나타냄을 알았다. 그리고 이 측광계의 장점으로 나타난 CN지수와 CN 특이성과는 특별한 관계를 찾기가 어려웠고, 이 측광계만으로는 상도계급의 구분을 다른 측광계 만큼 분명하게 결정짓기가 어려웠다. 그러나 표면중력과이 측광계의 색지수와의 관계를 본 결과 초거성, 거성, 주계열성을 비교적 잘 구분해 낼 수 있었다.

• Korean Journal of Materials Research
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• v.3 no.3
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• pp.215-222
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• 1993

Malononitrile(MN) as a reactive additive was added to Diglycidyl ether of bisphenol A (DGEBA)/Methylene dianiline (MDA) system in order to modify a thermosetting epoxy resin. Cure ki. netics and cure mechanism of this modified system were investigated by using DSC(differential scanning calorimetry) and FT-IR(fourier transform infrared spectrometry). Cure kinetics gave an information that the DGEBA/MDA system modified with MN should cure at over $110^{\circ}C$ after curing at about $80^{\circ}C$ for the complete curing. The activation energy of the first cure was nearly constant and that of the second cure was increased as the MN content was increased. Cure mechanism for the system was investigated with the samples cured every $30^{\circ}C$, from $80^{\circ}C$ to $170^{\circ}C$, for Ihr. It was known that the cure reactions of the epoxy-diamine system were composed of PA -E, SA - E and E-OH reactions. Beside these three reactions, in the DGEBA/MDA/MN system PA-CN and CN-OH reaction was found.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.82-86
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• 1999

An experimental study has been carried out to reduce bending load, surface roughness and springback in bending process of stainless steel sheets. A U-bending test has been performed to investigate appropriate process parameters for getting better surfaces and accurate dimensions of stainless steel products. In the test, selected process parameters are die material, lubricant, and die clearance. Die materials used in the test are STD11(HRC60), STD11(TiCN), and AMPCO. From the test results, we can suggest that AMPCO dies are most suitable for reducing bending load and surface roughness of stainless steel sheets. And STD11 dies are favorable for avoiding spring-back in the stainless steel sheet-bending.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.165-168
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• 2009

현재 IT서비스 업체에서 새로운 성장동력으로 떠오르고 있는 분야가 융복합사업(IT+IT, IT+장비, IT+장비+시공)이라고 불리우는 컨버전스 프로젝트이다. 기존의 IT분야의 프로젝트와는 전혀 다른 특성을 갖고 있는 컨버전스 프로젝트에 대한 IT서비스 업체의 준비는 아직 미흡한 것이 현실이다. LG CNS에서는 이런 현실에서 컨버전스 프로젝트의 특성에 맞추어 기존 프로젝트 관리자(Project Manager)의 역할을 재정의하고 이를 현장에 적용시키기 위해 그동안의 컨버전스 프로젝트를 수행하면서 얻은 이슈에 HPT(Human Performance Technology; 수행공학)를 적용하여 조직적인 차원에서 프로젝트 관리자의 육성 로드맵을 만들고 이를 확산시키는 활동을 진행하고 있다. 이에 본 발표에서는 HPT측면에서 컨버전스 프로젝트 이행역량을 강화하기 위한 사례를 소개하고자 한다.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.58-65
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• 2011

The bacterial uranium(VI) reduction and its resultant low solubility make this process an attractive option for removing U from groundwater. An impact of aqueous suspending iron phase, which is redox sensitive and ubiquitous in subsurface groundwater, on the U(VI) bioreduction by Shewanella putrefaciens CN32 was investigated. In our batch experiment, the U(VI) concentration ($5{\times}10^5M$) gradually decreased to a non-detectable level during the microbial respiration. However, when Fe(III) phase was suspended in solution, bioreduction of U(VI) was significantly suppressed due to a preferred reduction of Fe(III) instead of U(VI). This shows that the suspending amorphous Fe(III) phase can be a strong inhibitor to the U(VI) bioreduction. On the contrary, when iron was present as a soluble Fe(II) in the solution, the U(VI) removal was largely enhanced. The microbially-catalyzed U(VI) reduction resulted in an accumulation of solid-type U particles in and around the cells. Electron elemental investigations for the precipitates show that some background cations such as Ca and P were favorably coprecipitated with U. This implies that aqueous U tends to be stabilized by complexing with Ca or P ions, which easily diffuse and coprecipitate with U in and around the microbial cell.