• Steel and Composite Structures
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• 제32권3호
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• pp.293-304
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• 2019

In the present paper, the element free Galerkin (EFG) method is developed for geometrically nonlinear analysis of deep beams considering small scale effect. To interpret the behavior of structure at the nano scale, the higher-order gradient elasticity nonlocal theory is taken into account. The radial point interpolation method with high order of continuity is used to construct the shape functions. The nonlinear equation of motion is derived using the principle of the minimization of total potential energy based on total Lagrangian approach. The Newmark method with the small time steps is used to solve the time dependent equations. At each time step, the iterative Newton-Raphson technique is applied to minimize the residential forces caused by the nonlinearity of the equations. The effects of nonlocal parameter and aspect ratio on stiffness and dynamic parameters are discussed by numerical examples. This paper furnishes a ground to develop the EFG method for large deformation analysis of structures considering small scale effects.

• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1435-1450
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• 2004

Experimental data are presented which describe the effects of a combustor-level high free-stream turbulence on the near-wall flow structure and heat/mass transfer on the endwall of a linear high-turning turbine rotor cascade. The end wall flow structure is visualized by employing the partial- and total-coverage oil-film technique, and heat/mass transfer rate is measured by the naphthalene sublimation method. A turbulence generator is designed to provide a highly-turbulent flow which has free-stream turbulence intensity and integral length scale of 14.7% and 80mm, respectively, at the cascade entrance. The surface flow visualizations show that the high free-stream turbulence has little effect on the attachment line, but alters the separation line noticeably. Under high free-stream turbulence, the incoming near-wall flow upstream of the adjacent separation lines collides more obliquely with the suction surface. A weaker lift-up force arising from this more oblique collision results in the narrower suction-side corner vortex area in the high turbulence case. The high free-stream turbulence enhances the heat/mass transfer in the central area of the turbine passage, but only a slight augmentation is found in the end wall regions adjacent to the leading and trailing edges. Therefore, the high free-stream turbulence makes the end wall heat load more uniform. It is also observed that the heat/mass transfers along the locus of the pressure-side leg of the leading-edge horseshoe vortex and along the suction-side corner are influenced most strongly by the high free-stream turbulence. In this study, the end wall surface is classified into seven different regions based on the local heat/mass transfer distribution, and the effects of the high free-stream turbulence on the local heat/mass transfer in each region are discussed in detail.

• 한국심리학회지:법
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• 제12권1호
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• pp.35-51
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• 2021

자유의지에 대한 믿음은 인간 행동의 원인과 행위에 따른 책임을 판단하는데 필요한 개념으로서 신경과학, 철학, 윤리학, 형법 등 다양한 학문 분야에서 자유의지의 개념에 대한 논쟁이 이어지고 있다. 자유의지와 결정론척도((FAD-Plus; Paulhus & Carey, 2011)는 개인의 자유의지에 대한 믿음과 관련된 구성요소를 측정하는 검사도구로, 영미권을 중심으로 개발되어 최근 국내에도 번역 소개되었다. 본 연구는 기존의 탐색적 요인분석을 실시한 선행연구에서 나아가 다양한 연령대와 사회경제적 배경을 가진 1000명의 일반인을 대상으로 확인적 요인분석을 실시하였다(연구 1). 모형의 적합성, 집중타당도, 판별타당도를 통하여 해당 척도의 신뢰성과 타당성을 확보하였다. 이후, FAD-Plus 척도의 하위문항인 '자유의지에 대한 믿음'이 귀인편향 및 통제소재와 어떠한 관계를 보이는지 살펴보았다(연구 2). 총 83명의 피험자들을 대상으로 분석을 실시한 결과 자유의지에 대한 높은 믿음은 부정적 행위에 대한 처벌판단, 내부귀인과 정적인 상관을 보였으나 긍정적 행위에 대한 보상판단에서는 유의한 관계를 보이지 않았다. 이를 통해 기존에 한국판으로 번안된 FAD-Plus 척도가 일반인들을 대상으로도 타당함을 검증하였으며, 자유의지에 대한 믿음, 귀인편향, 통제소재, 행위판단과의 관계를 살펴볼 수 있었다. 본 연구의 한계, 정책적 함의, 그리고 향후 연구 방향에 대해 논의하였다.

• 한국정보과학회논문지:정보통신
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• 제37권3호
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• pp.167-174
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• 2010

최근에 비 구조적 피어투피어 시스템을 위해 분산적으로 재결정위상을 구성하는 위상 제어 프로토콜이 제안되었다[1]. 본 논문에서는 재결정위상이라고 불리는 이러한 계층적 위상이 척도 없는 거듭제곱 법칙 망임을 보인다. 우리는 재결정 위상의 분산된 구성을 위한 알고리즘의 프로세스를 모형화 하고, 평균 장 점근법(Mean field Approximation)과 연속체 이론(Continuum theory)에 근거를 두고 분석하여, 구성된 재결정 망이 척도 없는 망임을 보였다. 위상제어 알고리즘을 따르는 각 노드는 더 선호하는 노드에 대한 연결을 추가하고, 가장 비선호하는 노드에 대한 연결을 제거한다. 다시 말해, 알고리즘에 따라, 각 피어는 자신이 알고 있는 피어들 중에서 최고의 적중률(또는 검색 능력 혹은 선호도)을 가지고 있는 노드들과 연결을 추가하고, 최저의 적중률을 가진 노드들과의 연결을 끊는다. 이것은 비구조적 피어투피어 망에서 재결정 위상을 구성하기 위한 지역적인 프로세스를 실제적으로 표현한다. 우리는 차수의 분포를 분석적으로 유도한다. 분석 결과, 만들어지는 재결정 위상은 척도 없는 망이며, 이것의 거듭제곱 법칙의 지수$\gamma$는 3 이다.

• 아동학회지
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• 제31권6호
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• pp.35-50
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• 2010

Joint attention, language development, and the relationship between these two variables were compared in infants from multi-cultural and Korean families. Joint attention was observed in both the Early Social Communication Scale (ESCS) and in infant-mother free play. Language development was evaluated by means of the MacArthur-Bates Communicative Development Inventory-Korean. There were no group differences in initiating and responding to joint attention in ESCS. However, in infant-mother free play, joint attention episodes were less and shorter in duration with infants from multi-cultural families than in Korean infants. The size of both the expressive and receptive vocabulary was also smaller in infants from multi-cultural families than in Korean infants. In terms of Korean infants, mean duration of joint attention episodes in free play showed a significant positive correlation with the size of the expressive vocabulary and initiating joint attention in ESCS also showed a significant positive correlation with the size of receptive vocabulary. However, none of the measures of joint attention indicated a significant relationship with the size of either expressive or receptive vocabulary in infants from multi-cultural families.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1190-1200
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• 2010

A method was developed to determine resilient modulus for crushed rock-soil mixtures whose usage has been increased recently without engineering specifications. The method is based on the subtle different modulus called nonlinear dynamic modulus and was lately implemented in residual soils and engineered crushed-stones. Hereby. the same method was expanded to crushed rock-soil mixtures containing as large grain diameter as 300mm. The method utilize field direct-arival tests for the determination of maximum Young's modulus, and a large scale free-free resonant column test, which is recently developed to is capable to test as large grain diameter as 25mm, for modulus reduction curves. The prediction model of resilient modulus was evaluated for crushed rock-soil mixtures of a highway construction site at Gimcheon, Korea.

• 한국환경교육학회지:환경교육
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• 제22권4호
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• pp.53-65
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• 2009

Saemangeum is the largest reclaimed land in Korea. Saemangeum is the large scale project responding to the economic demand of globalization, and a government initiated new development business with a vision of global Free Economic Zone(FEZ). Jeollabuk-province conducted a international competition to establish a global-scale, creative development plan and grow the Saemangeum as an international destination of economy, and a world-wide brand. SGFEZ has much to offer in terms of tourists attractions and breathtaking scenery. And tourism is one of the important industry in SGFEZ. Many tourist facilities will be construct in SGFEZ. Environment is the important issue in many field of study. Recent days, green growth come into the spotlight in Korea. But even as SGFEZ prepares for its future global tourists attraction, so much of the tourism policy directions remains unconsidered. The objective of this study was to suggest tourism policy direction, especially concentrated on ecology tourism policy direction of Saemangeum Gunsan Free Economic Zone(SGFEZ).

• Steel and Composite Structures
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• 제26권3호
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• pp.273-287
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• 2018

Buckling and free vibration analysis of sandwich micro plate (SMP) integrated with piezoelectric layers embedded in orthotropic Pasternak are investigated in this paper. The refined Zigzag theory (RZT) is taken into consideration to model the SMP. Four different types of functionally graded (FG) distribution through the thickness of the SMP core layer which is reinforced with single-wall carbon nanotubes (SWCNTs) are considered. The modified couple stress theory (MCST) is employed to capture the effects of small scale effects. The sandwich structure is exposed to a two dimensional magnetic field and also, piezoelectric layers are subjected to external applied voltages. In order to obtain governing equation, energy method as well as Hamilton's principle is applied. Based on an analytical solution the critical buckling loads and natural frequency are obtained. The effects of volume fraction of carbon nanotubes (CNTs), different distributions of CNTs, foundation stiffness parameters, magnetic and electric fields, small scale parameter and the thickness of piezoelectric layers on the both critical buckling loads and natural frequency of the SMP are examined. The obtained results demonstrate that the effects of volume fraction of CNTs play an important role in analyzing buckling and free vibration behavior of the SMP. Furthermore, the effects of magnetic and electric fields are remarkable on the mechanical responses of the system and cannot be neglected.

• KSBB Journal
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• 제7권1호
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• pp.79-83
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• 1992

Erwinia rhapontici를 Ca-alginate에 고정화시켜 고정화 세포의 반응특성을 고찰하고, STR, PBR을 이용하여 Palatinose의 생산을 검토하였다. Free cell과 고정화 세포의 반응최적 pH는 5.5-6.0, 반응 최적온도는$30-35^{\circ}C$로 동일하였으나 고정화에 의해 pH 및 온도 범위가 보다 넓어졌고, 이때 Free cell및 고정화 세포의 겉보기 Km갑슨 각각 0.13, 0.28M이었다. STR을 이용한 Palatonose 생산시 고정화 세포의 반감기는 약 380 시간으로 낮았으나, PBR을 통해 30일까지 안정운전이 가능하였다. PBR 운전시의 운전온도 30, $33^{\circ}C$에서 Palatinose수율 및 고정화 세포의 안정성은 거의 동일한 결과를 나타내었으며 이때 PBR생산성은 약 120g/l$\cdot$h이었고, Pilot scale인 50L 까지 성공적으로 Scale up 되었다.

• 대한조선학회논문집
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• 제34권1호
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• pp.41-49
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• 1997

작은 파 기울기(Ak=0.01)를 갖는 Stokes 파/평판의 경계층 및 반류에 대하여 엄밀 및 근사 자유표변 경계조건을 적용하여 Navier-Stokes 식을 수치해석하였다. 거시유동에서는 외부 흐름 압력 변화가 유선방향의 속도 성분을 가속 혹은 감속시키며 교차 유동의 방향 변화를 야기시킨다. 특히 반류는 역(逆)압력기울기 영역에서보다 순(順)압력기울기 영역에서 그 반응이 크며 정수 중에서의 값을 평균치로 하지 않고 편향되는 반류 편향 특성을 갖는다. 미시유동에서는 자유표면 경계조건이 경계층 및 근접/중간 반류영역에서 큰 영향을 미친다. 차수크기 추정은 계산 결과와 잘 일치하였으며 근사 자유표변 경계조건은 상당한 오차를 유발시킴을 알 수 있다.