• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.238-239
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• 2002

현대의 영구자석들은 Alnico 주조자석을 제외하고는 모두 자성분말을 이용한 분말야금학적인 소결자석 또는 본드자석 형태로 제조된다. 따라서 자성분말의 형상, 크기, 입도, 순도, 조성 등이 자석의 자기적 특성을 우선적으로 결정하며, 이러한 구조적, 화학적 인자들은 영구자석의 고성능화를 위해 자성분말 또는 결정립이 초미세화 함에 따라 자기 특성을 결정하는 더욱 중요한 요소로 작용하고 있다. 그러므로 이들 인자와 자기적 특성간의 상관관계를 정확히 규명하고 보다 잘 이해하는 것이 극대화된 자기 특성을 갖는 자성체를 개발하는데 절대적으로 필요하다. (중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.279-282
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• 2001

병렬프로그램을 멀티프로세서로 스케줄링하는 문제의 해를 구하기 위하여 본 논문에서는 확장된 유전자 알고리즘을 적용한다. 확장된 유전자알고리즘인 MSEGA는 각 노드의 선행관계에 관한 휴리스틱한 정보와 간단한 일차원 배열구조가 통합된 염색체 코딩방법과 염색체 구성인자 중 우성 유전인자의 형질을 다음세대로 존속시키는 교배연산자와 프로세서 효율성이 고려된 평가 함수등으로 순서제약이 있는 병렬프로그램 스케줄링 문제 및 FFT(Fast Fourier Transform)형태의 데이터 흐름도상에서 관련 연구 중 Hou의 유전자 알고리즘과 BEA(binary-exchange algorithm)에 의한 스케줄링 결과보다 전체실행시간에 있어 HSEGA에 의한 스케줄링이 더 우수함을 보였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.9-10
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• 2007

본 논문에서는 비접촉식 이온에너지 해석 방법(Noninvasive Ion Energy Analysis, NIEA)을 이용하여 이온에너지 분포함수를 계산하고, 이 분포의 정보를 몇 가지 양으로써 특성지을 수 있는 모니터링 인자를 제안 하였다. 이온 에너지 분포에 영향을 미치는 외부 조건들인 rf 전력, 압력, 전극 간격을 변화시키며 해당 에너지 분포함수의 형태 변화 및 모니터링 인자들의 변화 양상을 관찰 하였다. NIEA 방법으로 측정한 이온 에너지와 공정과의 연관성을 알아보기 위해 poly silicon etching을 수행하며 이온 에너지 분포를 측정하였으며, 이온 에너지와 etch rate이 같은 경향을 나타내는 것을 확인 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.83-83
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• 2020

지속되고 있는 기후변화의 영향으로 발생하는 기상현상들이 사회적 문제로 대두되고 있으며, 기후변화에 따른 국지적 극한 사상에 대한 전망은 수자원 활용 계획을 수립하고 대응하는 데 있어 필수적인 요소로 인식되고 있다. 이에 기후, 수문, 지리, 생태 및 환경 등의 다양한 영역에서 신뢰할 수 있는 공간적 강수량의 요구가 증가하고 있지만 지형의 약 70%가 산악 지형인 우리나라의 경우 기존의 일반적 공간보간 기법인 IDW 및 크리깅 방법은 고도가 높은 지역의 기상인자를 추정하는 데 한계가 있는 것으로 평가 받고 있다. 프리즘(Precipitation-Elevation Regressions on Independent Slopes Model, PRISM) 기법은 지형적 특성을 고려한 격자형태의 기상인자를 생산할 수 있는 유용한 방법으로서 미계측 유역에 대한 신뢰할 수 있는 일 단위 강수량 추정을 위하여 SCE-UA (Shuffled Complex Evolution-University of Arizona) 기법을 활용하여 최적화 하였다. 본 연구결과는 PRISM 기법의 국내 적용 시 정확도 향상에 기여할 것으로 기대된다.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.72-79
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• 2003

In reliability based design(RBD) method, the distribution characteristics of mechanical properties of material are basic input variable. Therefore, distribution type and parameters of mechanical properties should be determined accurately. Until now, the properties were derived from tests with small, clear specimens. However, the test conditions should emulate as nearly as possible the way in which the timber would be used in practice and the test results should, as closely as possible, reflect the structural end use conditions to which the timber products would be subjected. In this study, structural timbers (38mm by 140mm, 3.0m long) were graded by visual assessment of growth characteristics and defects. And then bending tests were conducted on 498 structural size timbers. For each grade, the distribution type and the parameters of mechanical properties were determined for each grade. For the determination of best-fit distribution type, comparing of square error between distribution types and KS test were conducted. Best-fit distribution type of bending strength(MOR) is weibull distribution for all grade. In case of MOE, normal distribution is best-fit.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.236-248
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• 2013

In this study, 37 subjects with normal facial shape and normal occlusion are classified and reference value for such classification was investigated. Difference in position of maxillary incisor was studied according to the cl assification. Moreover, by investigating correlation between factors affecting forehead morphology and positio n of maxillary incisor, following results have been obtained. 1. Morphology of forehead can be classified as angular type, round type, straight type, and concave type. 2. There were no specific reference value for evaluation of forehead morphology but possibilities of evaluating forehead morphology using S value and forehead length (Tri-Gla) still remain. 3. There were no correlation between forehead morphology and position of maxillary incisor. 4. Forehead inclination and Andrew analysis show statistically significant negative correlation. That is, as forehead inclination increases, maxillary incisor is positioned posteriorly and this relationship can be shown as following equation, Andrew analysis = -0.39*Forehead inclination.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.1
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• pp.39-67
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• 1987

The purpose of this thesis is to suggest objective basic data for the environmental design through the quantitative analysis of the visual quality included in the physical environment of forest landscape. For this, landscape values of forest landscape have been evaluated by using the Iverson method, the images structure of forest landscape's main utilizing space have been analysed by the factor analysis algorithm, degree of visual preferences have been pleasured mainly by questionnaries and SBE method, and finally these thesis can be summarized as fallow LCP with high values of Iverson factors I and IV yield high landscape value. Specifically, Iverson factor IV has been found to play the dominant. For all experimental points, significant seasonal variations in S.D. scale values have been observed. In natural parks, where artificial structures are complementary to the natural landscape, main factors of image are S.D. scales such as the visual sequence, the formal simplicity of structures, the emphasis, the unification of heterogeneous factors and the assimilation. Factors covering the spatial image of natural parks have been found to be the overall evaluation, the individual characteristics, the tidiness, the potentiality, the dignity, the intimacy and the space volume. For all seasons, factors such as the individual characteristics, the dignity, the tidiness, the potentiality, yield high factor scores. As for factors determining the degree of visual preference, variables such as the summit, the skyline, rocks, the water and the degree of natural destruction by artificial structures yield high values for all seasons.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.7-18
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• 2006

The Purpose of this study is to develop landscape Preference and define elements of difference in landscape preference of the 1-span Steel Box Girder Bridge by Bridge Shape Parameters(BSP) through Design of Experiments. Lately, the 1-span Steel Box Girder Bridge is dominations much component ratio and the Steel Box Girder Bridge has strong Points that is economically Profitable and management has easy when construct. but landscape preference of the 1-span Steel Box Girder Bridge was evaluated low because impression of landscape is being surfeited and dulled. Do to consider optimization in design that give change to Bridge Shape Parameters(BSP) to supplement this shortcoming in this study. Therefore, this study changes Bridge Shape Parameters(BSP) and extract elements that influence in landscape preference of the 1-span Steel Box Girder Bridge. and based on the design that consider landscape Preference of the 1-span Steel Box Girder Bridge, some essential guidelines for rational design of the 1-span Steel Box Girder Bridge suggested.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.543-550
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• 2005

In the present work, modulus of rupture (MOR), flexural toughness properties $(I_{30}\;and\;W_{2.0})$ and workability (slump) of high performance hybrid fiber reinforced concrete (HPHFRC) mixed with micro-fiber (carbon fiber) and macro-fiber (steel fiber), and replaced with a fine mineral admixture such as silica fume (SF) are characterized through the analysis of variance (ANOVA). Data of MOR, $I_{30}(or W_{2.0})$ and slump are used as the characteristic values to estimate flexural performance and workable property of HPHFRC. Specially, an experimental design was Planned according to the fractional orthogoanl nay method to reduce experimental number of times. The experimental results show that steel fiber is a considerable significant factor in MOR and I30 $(W_{2.0})$. Based on the significance of experimental factors about each characteristic factors, the following evaluation can be used: Experiment factors which reduce slump most remarkably are carbon fiber, steel fiber, silica fume order.; Those that improve MOR most significantly are silica fume $({\fallingdotseq}\;carbon\;fiber)$, steel fiber order; Those that increase flexural toughness most distinctly are silica fume, carbon fiber, steel fiber order. It is obtained that the combination of steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $5.0\%$ is the experimental condition that improve MOR and flexural toughness excellently with workability ensured within the experiment.

• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.163-170
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• 1988

The MNDO calculations were performed on the various rotamers of N-methyl formamide, N,N-dimethyl formamide, N-methyl acetamide, and N,N-dimethylacetamide in order to investigate the contribution of the one-electron and the steric effect on their rotational barriers about the C-N bond. Results show that while the conformational stabilities of formamides depend mainly on the one-electron factor, those of acetamides depend mainly on the steric factor. According to results obtained by calculations on the rotational barriers about C-N bond, for N-monosubstituted amides the steric effect is larger in the rotational ground state than in the transition state and for N,N-disubstituted amides the steric effect is larger in the rotational transition state.