• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.973-979
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• 2001

Tin-doped indium oxide (ITO) thin films were deposited using r.f. magnetron reactive sputtering and the electrical properties, such as the resistivity, carrier concentration and mobility, were investigated as a function of the sample position under a given magnetron sputtering condition. The nonhomogeneity of the electrical properties with the sample position was observed under a given magnetron sputtering condition. The resistivity of ITO thin film on the substrate which corresponded to the center of the target had a minimum value, 2∼4$\times$10$\^$-4/$\Omega$$.$cm, and it increased symmetrically when the substrate deviated from the center. The density measurement result also showed that ITO thin film deposited at the center has a maximum density of 7.0g/cm$^3$, which was a relative density of about 97%, and the density decreased symmetrically as the substrate deviated from the center. The nonhomogeneity of electrical properties with the deposition position could be explained with the incidence angle of the source beam alpha, which is related with an atomic self-shadowing effect. It was confirmed experimentally that the density in film affect both the carrier mobility and the conductivity. In the case where the density of ITO thin film is 7.0g/cm$^3$, the magnitude of the mean free path was identical with that of the grain size(the diameter of column). However, in the other cases, the mean free path was smaller than the grain size. These results showed that the scattering of the free electrons at the grain boundary is the major factor for the electrical conduction in ITO thin films having a high density, and there exists other scattering sources such as vacancies, holes, or pores in ITO thin films having a low density.ing a low density.

• Explosives and Blasting
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• v.38 no.1
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• pp.23-29
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• 2020

The measurement technique with dynamic shock sensor was widely used in academic experiment for blasting and impact. However, most of dynamic sensors are expensive so that it needs to be protected by external housing structures or damping devices. In this study, the calibration method for dynamic shock sensor under the distortion by external structures. Hopkinson pressure bar system was adopted to measure the input acceleration to the sensor, and it was compared to the acceleration measured by accelerometer with customized damping device. Consequently, it is conclued that this method can be useful to calibrate the dynamic shock sensor under the linear distortion.

• Journal of Korea Water Resources Association
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• v.38 no.1
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• pp.25-35
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• 2005

Nowaday the amount of water resource to generate the hydro-power energy has decreased as that of the water supply has increased. In case that the national market of the energy will be in free competition, the energy producer need to suggest the amount of the optimal supply with the hydrological reliability for a deal. In this study the optimal reservoir operation was performed by the linear programming and the optimal reliabilities of inflows and the power supply were obtained by the one dimensional search technique to estimate the energy with the optimal inflow reliability which the power system of the Yongdam multipurpose dam in Geum river can produce. And the main results were presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.239-245
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• 2019

RISC-V is a free and open ISA enabling a new era of processor innovation through open standard collaboration. Born in academia and research, RISC-V ISA delivers a new level of free, extensible software and hardware freedom on architecture, paving the way for the next 50 years of computing design and innovation. In this paper, according to the emergence of RISC-V architecture, we describe the RISC-V processor instruction set constituted by arithmetic logic, memory, branch, control, status register, environment call and break point instructions. Using ModelSim and Quartus-II, 38 instructions of RISC-V has been successfully simulated and synthesized.

• Journal of Korean Library and Information Science Society
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• v.38 no.4
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• pp.241-255
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• 2007

Leisure is not only free time, It is free affairs so as approve from labour thus It must be going forward quasi-public. our public library must build up role of public facilities for leisure, because of it has historicity and synchronism of public leisure facilities from the existence of our modern library.

• Landscaping Tree
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• s.112
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• pp.38-41
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• 2009

인천경제자유구역 내의 중앙공원이 2009년 9월에 준공하여 일반시민들에게 개장되었다. 센트럴파크는 동고서저와 강으로 대변되는 한반도의 지형적 특색을 담고 있으며 동고서저는 구릉이 있는 산책로와 낮은 잔디밭으로, 강은 수로로, 다도해 남해는 인공 섬이 있는 수변 공간으로 연출돼 있으며 인공으로 조성된 수로에는 수상택시가 다니고 있다. 지하에는 2,700여대가 추자할 수 있는 주차장을 공원과 분리하여 조성하였고 수로주변에는 보행자 산책로, 자전거도로 등이 조정되고 추후 공원 내 박물관 및 생태관이 조성될 예정이다. 센트럴 파크는 인천광역시 송도동 24-5번지 일원에 위치하고 있으며 면적은$411,319m^2$, 사업기간은 2007. 2. 1 ~ 2009. 7. 31, 사업비는 1,900억원(공원 1,200억원, 주차장 700억원)정도이며 주요시설로는 해수 수로, 수상택시 및 무빙스테이지, 지하주차장, 조각원, 정형식 정원, 초지원, 보트하우스, 비지터센터 등이 있다.

• Journal of Nutrition and Health
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• v.15 no.1
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• pp.30-38
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• 1982

Experiments were carried out in order to compare the natural antioxidants in the acetonitril extracts of raw and baked seeds of Korean sesame and perilla by thin layer and gas chromatography. The sample was dissolved in n-pentane and extracted with acetonitril and the acetonitril extract was separated by thin layer chromatography using silica gel. The spots were detected by spraying with 2, 6 -dichloroquinone -4-chlorimide, phosphomolybdic acid and dimethylamine as chromogenic reagents. Natural antioxidant, such as ${\delta}-tocopherol$ detected in raw and baked sesame and perilla seed oil by TLC and sesamol was detected only in raw and baked sesame seed oil by GC.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.12
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• pp.971-982
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• 1989

An integrating position estimation algorithm has been developed for the navigation system of a free-ranging AGV system. The navigation system focused in this research work consists of redundant wheel encoders for the relative position measurement and a vision sensor for the absolute position measurement. A maximum likelihood method and an extended Kalman filter are implemented for enhancing the performance of the position estimator. The maximum likelihood estimator processes noisy, redundant wheel encoder measurements and yields efficient estimates for the AGV motion between each sampling interval. The extended Kalman filter fuses inharmonious positional data from the deadreckoner and the vision sensor and computes the optimal position estimate. The simulation results show that the proposed position estimator solves a generalized estimation problem for locating the vehicle accurately in space.

• Journal of the Korean Ceramic Society
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• v.38 no.6
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• pp.568-574
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• 2001

수정된 기체투과법을 이용하여 다공성 지지체의 기공크기를 평가하였다. 본 연구에서의 수정된 기체투과법은 기공 내에서 유체흐름이 Hagen-Poiseiulle 법칙이 성립하는 영역으로 압력을 조절하여 투과유량을 측정하는 방법을 말한다. 수정된 기체투과법의 적합성 여부는 유체의 Reynolds number 및 기체분자의 평균자유행로를 통해 검토하였다. 다공성 지지체의 유량의 시간변화로부터 대표치를 결정하여 기공크기로 환산하였다. 본 방법에 의해 평가된 다공성 지지체의 기공크기는 30$\mu\textrm{m}$~80$\mu\textrm{m}$ 이었으며, 평균치는 50$\mu\textrm{m}$로 평가되었다. 한편 화상해석법과 비교.분석한 결과 수정된 기체투과법을 통해 평가된 기공은 내부채널의 가장 작은 부분을 나타내는 것으로 확인되었다.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.29-38
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• 2014

G-quadruplex를 형성하는 DNA연속체는 텔로미어에서 발견된다. 지금까지의 연구 결과에 따르면 G-quadruplex는 다양한 유전질환과 암과의 상관관계가 있으며, 따라서 G-quadruplex에 대한 연구는 제약 개발 분야에서 활발하게 진행되고 있다. G-quadruplex는 두 개 이상의 G-tetrad들이 쌓여서 형성된 복합체를 의미하며, G-tetrad란 4개의 구아닌 염기들이 Hoogsteen의 수소결합 통해, 정사각형의 평면을 이룬 물질을 일컫는다. 이때, 알칼리 금속 이온이 G-quadruplex에서의 G-tetrad 복합체 형성에 중요한 역할을 한다는 선행연구 결과가 있다. 특히, 알칼리 금속 중 $K^+$이 가장 G-quadruplex와 결합을 잘 한다고 알려져 있는데 그 이유에 대한 분자적 관점의 설명이 이루어져 있지 않다. 따라서 본 연구에서는 먼저 G-quadruplex의 기본 구성 단위 구조인 G-tetrad와 알칼리 금속 결합체들의 수용액상에서의 구조적, 열역학적 특징을 정량적으로 비교, 분석하였다. 또한, 양자화학적 방법으로 계산된 수용액 상태에서의 결합구조에 대한 용매화 자유 에너지 계산을 수행하여 G-quadruplex 간의 자기 조립 (self-assembly) 현상을 설명하였다.