• The Korean Journal of Ecology
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• v.10 no.4
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• pp.165-173
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• 1987

Odong Island, Yeosu, is the one of the Hallyosudo National Marine Park. The vegetation of this island was surveed from July, 1986 through April, 1987. By the Braun-Blanquet's method, the vegetation of Odong Island was classified into 7 communities and 4 afforestations; that is, Pseudosasa japonica community and Phyllostachys bambusoides afforestation (bamboo stands), Mallotus japonicus, Quercus acutissima community, Prunus serrulata var. spontanes and Celtis sinenesis afforestation (deciduous forests), Pinus densiflora, Pinus thunbergii community, Chamaecyparis pisifera afforestation (evergreen needle-leaved forests), and Castanopsis cuspidata var. sieboldii-Camellia japonica and Machilus thunbergii-Camellia japonica community (evergreen broad-leaved forests). Based on the classification, the actual vegetation map of the island was prepared in scale 1:2,600. Judging by the DBH class distribution and many other informations, ww can expect that the coniferous forests area of the island will be replaced by evergreen broad-lea ed forests after a few future.

• 기계와재료
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• v.11 no.2 s.40
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• pp.111-118
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• 1999

Test Results and Status of development of the urban transit maglev system(UTM-O1) are reported. Maglev Project Team in KIMM, in cooperation with Hyundai Precision Company and the Korea Electrotechnology Research Institute(KERI), has successfully finished the second stage development project (1995. 5-1998. 8) and demonstrated a prototype two vehicle consisted urban maglev train operating in the speed range of 50km/h. In this paper, we report various test results of the UTM-01 system, present status of quo and future prospect, and what have been done so far to improve the performance of the maglev system overall.

• Korean Journal of Child Studies
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• v.13 no.2
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• pp.65-81
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• 1992

The purpose of this study was to investigate children's conceptions about gender and the relation between gender conceptions and preference for gender related tasks. 130 children were interviewed about gender and gender related tasks. Data were analyzed with the component model of gender schema. Results indicated that children's gender schema in the attitudes domain was significantly different with age in all components but not different with sex. The gender schema in the knowledge domain was significantly different with age in within component and between component links, and with sex in the gender label-component and within component links. The difference between the gender inhibitory score and gender facilitative score was significantly different with age, sex, and children's gender schema. The findings that gender schema influenced the children's preferences for gender related tasks suggests a theoretical rationale of gender schema theory.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1-6
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• 1991

This paper is concerned with the design of a robust tracking controller using a state observer on a robotic manipulator under the disturbance. The controller is designed to follow a step or ramp reference input without steady state error in the presence of a disturbance and a system parameter variation. In most cases, since all the state vectors are not measured, unmeasurable state vectors must be estimated or reconstructed. A reduced order observer is proposed to estimate unmeasurable state vectors of the non-linear system. Some problems are caused by the Coulomb friction, the disturbance, and the spring effect of a link between the drive motor and the manipulator arm. The state variables, directly measured and estimated by the reduced order observer, are fed back to the controller. When the robot system exhibits the 'limit cycle, the feedback gains initially obtained by optimal control theory are changed. As a result, the limit cycle is eliminated by the new controller gains,

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.467-474
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• 1993

Viscous flow and heat transfer phenomena in an axisymmetric cylinder which models a diesel engine have been numerically studied. In order to search for a way to minimize numerical diffusion, the effectiveness and the appropriateness of two selected numerical schemes for convective terms in the governing equations have been tested. They are Linear Upwind Difference Scheme and Hybrid Scheme. Using a standard k-.epsilon. turbulence model, the calculation has been carried out basically up to 180.deg. of crank angle. As a result, it was shown from comparison with previous experimental data that Linear Upwind Difference Scheme is less influenced than Hybrid Scheme by the numerical diffusion and it was suggested that these effects of numerical diffusion can be more significant than those due to turbulence modeling.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.1-9
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• 1990

A variational approach with reference volume and adjoint structure concepts is applied for the structural design densitivity analysis of geometrically nonlinear structures. A general form of sensitivity equation is used and then nonlinear finite element procedure is implemented for the discretized structural model. Usability and effectiveness of the variational approach for the design sensitivity analysis of geometrically nonlinear structural responses are verified through a numerical example.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.1915-1926
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• 1995

The Fatigue characteristics of 8-harness satin woven CFRP composites with a circular hole are experimentally investigated under constant amplitude tension-tension loading. It is found in this study that the fatigue damage accumulation behavior is very random and history-independent, and the fatigue cumulative damage is linearly related with the mean number of cycles to a specified damage state. From these results, it is known that the fatigue characteristics of CFRP composites satisfy the basic assumptions of Markov chain theory and the parameter of Markov chain model can be determined only by mean and variance of fatigue lives. The predicted distribution of the fatigue cumulative damage using Markov chain model shows a good agreement with the test results. For the fatigue life distribution, Markov chain model makes similar accuracy to 2-parameter Weibull distribution function.

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.82-95
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• 1994

인지의 주체로서 마음을 연구하는 인지과학은 인간 마음이 가지고 있는 본성을 탐구하고 인간이 가지고 있는 정보전달체계(information processing system)를 밝힘으로써 미를 컴퓨터에 응용하려는 것이 그 목적 중의 하나이다. 이러한 맥락에서 인식론도 어떤 명제를 믿는 것이 정당성을 갖느냐, 다시 말해서, 어떤 명제를 믿어야 하느냐는 규범적 문제보다는 실제로 우리가 어떻게 믿음을 형성하고 있느냐는 서술적인 문제에 중점을 두는 자연주의적 인식론이 큰 세력을 얻게 되었다. 자연주의적 인식론의 대두와 함께, 그것이 규범적인 문제를 다루는 전통적인 인식론과 이떠한 관계가 있는가에 많은 철학자들이 관심을 표명하였다. 그 중 콰인(W. V. O. Quine)은 자연주의적 인식론이 전통적인 인식론을 대체해야 한다는 급진적인 주장을 하였으며, 콘블리쓰(Hilary Kornblith)는 전통적인 인식론과 자연주의적 인식론이 같은 목표를 향한 다른 방법론을 쓰는 것이므로 적어도 전통적인 인식론자들은 자연주의적 인식론의 영향을 받아야만 한다고 단언하였다. 본고에서는 이 두 사람의 논증을 살펴보고 전통적인 인식론과 자연주의적 인식론이 얼마나 밀접하게 연결되어 있는가를 검토해 보기로 하겠다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.260-261
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• 2000

광결정(photonic crystal)은 빛의 파장 크기 정도의 격자 상수를 지닌 1차원, 2차원, 또는 3차원의 주기적인 구조이다. 광결정에는 광밴드갭(photonic bandgap)이라는 빛의 자발 방출이 억제된 진동수의 영역이 존재하는데, 이 영역을 이용하여 빛의 자발 방출을 조절하고 빛의 흐름을 제어할 수 있다. $^{[1]}$ 지난 10여년간 2차원, 3차원의 광결정 구조에 대한 연구가 많이 이루어져 왔는데, 최근에는 슬랩 도파관(slab waveguide)에 2차원 광결정을 만든 구조에 대한 연구가 활발하게 진행중이다. 이 구조는 평면 방향으로는 광밴드갭 효과로 광모드를 가둘 수 있고 수직 방향으로는 전반사를 이용하여 모드를 가둘 수 있어서 3차원적인 모드 confinement 효과를 얻을 수 있다. [그림 1]의 (a)에 air-bridge 형태의 2차원 광결정 슬랩(photonic crystal slab) 구조를 도식적으로 나타내었고, (b)에는 본 연구실에서 제작한 구조 표면의 scanning electron micrograph을 나타내었다. 현재 몇몇 연구 그룹에서 이와 같은 광결정 슬랩 구조를 이용한 반도체 레이저를 실현하는데 성공하였다.$^{[2,3]}$ (중략)

• Magazine of the Korea Concrete Institute
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• v.9 no.1
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• pp.195-206
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• 1997

비선형 layered 유한요소법과 비선형 프로그래밍 기법에 의하여 주어진 기존의 철근콘크리트 보의 휨강도 및 연성을 근사하게 나타낼 수 있는 강섬유고강 철근콘크리트 보(Reinforced Steel Fibrous Concrete Beam : RSFC Beam)의 인장 및 압축철근량, 강섬유의 혼입률 등을 산정하였다. 개발된 모델을 이용하여 콘트리트의 압축강도 및 철근비가 서로 다른 일반 철근콘크리트 보에 있어서 강섬유보강 콘크리트를 사용할 경우, 기존 철근을대체하는 강섬유의 량과 또한 이로 인한 인장 \ulcorner 압축 철근량의 변화량을 조사하였다. 기존 문헌에 나타난 강섬유보강 콘크리트보의 전간강도식을 이용하여 일반 철근콘크리트보와 비교하여 강섬유보강 철근콘크리트 보에서 증가될 수 있는 스터럽의 간격을 산정하였다.