• 한국광학회지
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• 제28권6호
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• pp.273-280
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• 2017

본 논문에서는 낮은 도로 조명을 위한 freeform reflector를 설계하였다. 높이에 비해 넓은 차선까지 배광을 보내야 하는 낮은 도로 조명의 경우, 기존의 등주식 도로 조명에 비해 균제도를 맞추기 힘들다는 단점이 있다. 조명 등급 M3를 만족시키기 위해 reflector를 part 9개로 나누어 part 별 반사면의 기울기를 변화시켜 원하는 배광을 갖도록 하였고, 각 점을 기준으로 fitted curve를 그려 이에 따른 수식을 도출하였다. LightTools의 street light simulation을 통해 M3 조명 등급에 만족하는 것을 확인하였고 직접 제작하여 실제 도로상에서 조명 등급을 만족시키며 설계 결과에 대한 타당성을 입증하였다.

• ETRI Journal
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• 제22권2호
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• pp.20-31
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• 2000

Much research on natural language processing (NLP), computational linguistics and lexicography has relied and depended on linguistic corpora. In recent years, many organizations around the world have been constructing their own large corporal to achieve corpus representativeness and/or linguistic comprehensiveness. However, there is no reliable guideline as to how large machine readable corpus resources should be compiled to develop practical NLP software and/or complete dictionaries for humans and computational use. In order to shed some new light on this issue, we shall reveal the flaws of several previous researches aiming to predict corpus size, especially those using pure regression or curve-fitting methods. To overcome these flaws, we shall contrive a new mathematical tool: a piecewise curve-fitting algorithm, and next, suggest how to determine the tolerance error of the algorithm for good prediction, using a specific corpus. Finally, we shall illustrate experimentally that the algorithm presented is valid, accurate and very reliable. We are confident that this study can contribute to solving some inherent problems of corpus linguistics, such as corpus predictability, compiling methodology, corpus representativeness and linguistic comprehensiveness.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.129-130
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• 1997

국내 및 해외에서 생산 되는 윤활유에 Cloud-point curves 및 상용성 개념을 도입하여 이러한 데이터를 측정할수 있는 장치를 기존의 Light scatering, Neutron scatering, Visible Method등이 아닌 He-Ne Laser를 이용하여 측정하는 장치이다. He-Ne Laser을 이용하여 공중합체 용액의 Cloud-point curves를 측정하였고, 측정 Cloud-point curves 데\ulcorner를 연속열역학적 상평형관계식에 적용 coex istence curves를 추산하였으며 추산치와 측정치를 비교 검토하였다. 멀지 않은 해에는 이러한 분석장치가 상용화되어 윤활유 제품의 상용성을 평가하는 장치가 될 것으로 사료된다. 따라서, 기존 윤활유 제품 및 신제품의 상용성(compatibility)을 He-Ne Laser을 이용하여 측정하고 다른 일면으로는 윤활유 제품의 고품질화 및 제품의 경쟁력을 강화하는데 커다란 영향을 미치리라 사료된다.

• Journal of Forest and Environmental Science
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• 제22권1호
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• pp.71-75
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• 2006

P-V곡선에 의한 음나무 묘목 상층엽의 수분특성을 측정하였다. 음나무 잎의 최대팽압시의 삼투포텐셜은 -1.44 MPa 이었고, 초기원형질분리점의 삼투포텐셜은 -1.84 MPa, 초기원형질분리점의 상대함수율은 78.2%였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.131-136
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• 2003

CF8M cast austenitic stainless steel is used for several components such as primary coolant piping, elbow, pump casing, and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. In this study, three kinds of the aged CF8M specimen were prepared using an artificially simulated aging method. The objective of this study is to summarize the method of estimating ferrite contents, Charpy impact energy and J-R curve, and to evaluate the thermal embrittlement of the CF8M cast austenitic stainless steel piping used in the domestic nuclear power plants.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.719-723
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• 2002

The purpose of this study is to suggest the correlation of single-number ratings for sound insulation by floor impact. As a assessment method of impact sound insulation. we selected the IIC contour of ISO, A weighted sound level. Inverse A-weighting curve and L-Index of japanese industrial standard. And we estimated the single-number ratings by application the measured data of impact sound level to each method. The results showed that the coefficients of determination between each two single-number ratings were very high (more than 0.9169). And In the condition of same assessment method, the coefficient of determination for light-weight impact sound was higher than that for heavy-weight impact sound.

• Steel and Composite Structures
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• 제34권4호
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• pp.581-597
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• 2020

Light-Weight Concrete containing Expanded Poly-Styrene Beads (EPS-LWC) is an approved structural and non-structural material characterized by a considerably lower density and higher structural efficiency, compared to concrete containing ordinary aggregates. The experimental campaign carried out in this project provides new information on the mechanical properties of structural EPS-LWC, with reference to the strength and tension (by splitting and in bending), the modulus of elasticity, the stress-strain curve in unconfined compression, the absorbed energy under compression and reinforcement-concrete bond. The properties measured at seven ages since casting, from 3 days to 91 days, in order to investigate their in-time evolution. Mathematical relationships are formulated as well, between the previous properties and time, since casting. The dependence of the compressive strength on the other mechanical properties of EPS-LWC is also described through an empirical relationship, which is shown to fit satisfactorily the experimental results.

• 한국의류학회지
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• 제25권2호
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• pp.268-274
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• 2001

Dyeing properties of the colorants extracted from pomegranate hull on silk fabric were investigated. Pomegranate colorants were characterized by FT-IR analysis. Effects of dyeing condition and mordanting on dye uptake, color change and colorfastness were explored. Pomegranate colorants showed high affinity to silk fiber and its isotherm adsorption curve was Langmuir type. Therefore, ionic bond was involved in the adsorption of pomegranate colorants on to silk fiber. Mordants except Fe did not significantly increase dye adsorption. Pomegranate colorants produced mainly yellow color on silk fabric, but the silk mordanted with Fe showed yellow red color. Fastness to washing, perspiration, and rubbing was not improved by mordanting treatment, but light colorfastness was increased by Fe mordant.

• ETRI Journal
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• 제39권6호
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• pp.859-865
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• 2017

This paper presents a method for determining the optimum active-area width (OAW) of solar cells in a module architecture. The current density-voltage curve of a reference cell with a narrow active-area width is used to reproduce the current density profile in the test cell whose active area width is to be optimized. We obtained self-consistent current density and electric potential profiles from iterative calculations of both properties, considering the distributed resistance of the contact layers. Further, we determined the OAW that yields the maximum efficiency by calculating efficiency as a function of the active-area width. The proposed method can be applied to the design of the active area of a dye-sensitized solar cell in Z-type series connection modules for indoor and building-integrated photovoltaic systems. Our calculations predicted that OAW increases as the sheet resistances of the contact layers and the intensity of light decrease.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.96-101
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• 2004

Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal embrittlement at the reactor operating temperature. The objective of this study is to summarize the method of estimating ferrite content, Charpy impact energy and J-R curve and to evaluate the thermal embrittlement of the cast austenitic stainless steel piping used in the domestic nuclear power plants. The result of evaluation, two domestic nuclear power plants used CF-8M and CF-8A material has adequate fracture toughness after saturation.