• Transactions of the Korean Society of Mechanical Engineers B
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• 제32권1호
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• pp.23-29
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• 2008

Two high resolution compressive schemes, CICSAM(Ubbink, 1997) and HRIC(Muzaferija & Peric, 1999), in interface capturing method are reviewed briefly with respect to the extended forms suitable for unstructured meshes. And then those are applied to three typical test cases of translation test, shearing flow test and collapsing water problem with an obstacle. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method, which is based on the finite-volume technique and fully conservative. The calculated results show that CICSAM is better than HRIC with respect to accuracy and robustness, although either scheme can be used as a good choice for free surface or two-phase flow simulation.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.51-56
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• 2006

Several high resolution schemes such as OSHER, MUSCL, SMART, GAMMA, WACEB and CUBISTA are applied to two typical test cases of a translation test and a collapsing water column problem for the accurate capturing of fluid interfaces. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method, which is based on the finite-volume technique and fully conservative. The calculated results are found to show that SMART scheme gives the best performance with respect to accuracy and robustness.

• Journal of the Society of Naval Architects of Korea
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• 제45권1호
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• pp.10-17
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• 2008

In this paper an accurate and stable gridless method that can be applied to multi-dimensional convection problems is developed on a flow directional local grid. A two dimensional pure convection problem is calculated and more accurate and stable solution is obtained compared with other schemes in grid method. The tested numerical schemes include 1st-order upwind scheme, 2nd-order Leith scheme, 3rd-order MUSCL, and QUICK scheme. It is seen that more accurate results are expected when the schemes combined with a MMT control limiter.

• Journal of Ocean Engineering and Technology
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• 제7권1호
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• pp.56-61
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• 1993

Standard values in graphic porms are presented for the ratio of added wave resistance to the sun of added wave and wind resistances in head sea for three ship types, tanker, container ship and passenger ship. The effect of ship length on the ratio defined above is investigated for the three ship types. Obique sea added resistance is determined using wave direction reduction factor. The factor is obtained from model test results and cubic spline interpolation technique.

• Journal of Korean Home Economics Education Association
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• 제21권2호
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• pp.61-81
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• 2009

The purpose of this study was to develop Graphic Organizer as Advance Organizer. The 'Menu Planning and Food Selection' unit of second grade middle school Technology & Home Economics(revised curriculum of 2007) was selected as the study subject. The course of abstracting an essential education element got done $3^{rd}$ times. It abstracted the first essential education elements to analyze the presented sentence or a concept with the educational contents factor which is on the achievement standard of the area of dietary life from 5grade to 10grade in curriculum revised in 2007. The first 4 essential education elements selected were superiority and cultural value of Korean traditional meal, preparing a balanced diet for the family, food purchasing, and food selection based on the various information'. It abstracted second essential education elements that it concretized the first content factor on a unit of this study and solved overlapping when it was happened at the first contents factor and made connecting with between grade. The $3^{rd}$ essential education elements abstracted to classify the contents which abstracted essential education elements in second. And, it developed Graphic Organizer on a unit of 'Menu Planning and Food Selection' in eight-grade Technology & Home Economics based on the abstracted essential education elements. Graphic Organizer was developed in according to order of the way for making on a Concept Map of Heo In Sook(2000). Developed Graphic Organizer is all of 10 which are 'nutrition value on food of the season', 'harmony and combination of food', 'natural dressing and a garnish', 'the recipe', 'fermented food', 'a traditional instrument and a vessel', 'actor of food harm', 'present food', 'food quality certification' and 'selecting food with food information'.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제12권10호
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• pp.808-815
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• 2002

The nonlinear characteristics for hinge of a deployable missile control fin are investigated experimentally. The nonlinearity is caused by a worn or loose hinge and manufacturing tolerance and cannot be eliminated completely. The structural nonlinearity has an effect on the static and dynamic characteristics of the control fin. Therefore, it is necessary to establish the accurate nonlinear model for the hinge of the control fin. In the present study the existence of nonlinearities in the hinge is confirmed from the frequency response experiments such as tip random excitation and base sine sweep. Using the system identification method. especially, ″Force-state Mapping Technique″, the types of nonlinearities are identified and the nonlinear hinge model of the control fin is established.

• Transactions of the Korean Society of Mechanical Engineers
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• 제8권3호
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• pp.250-256
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• 1984

본 논문에서는 다관절 평면로봇팔의 작업영역 및 기하학적 최적설계에 대하여 연구하였다. 관절 이 두 개인 평면로봇팔의, 공간적 효율과 관계되는, 작업영역의 면적은 해석적으로 계산할 수 있 으나, 세 개 이상의 다관절 평면로봇팔의 작업영역의 면적은 일반적으로 단순하게 해석적으로 해 를 구하기가 매우 어렵다. 본 논문에서는 두 개의 그래픽 RAM을 가진 마이크로 컴퓨터를 사용 하여 작업영역의 면적을 근사적 도식법으로 구하고 이것을 이용하여 미리 임의의 작업점들이 지 정되었을 때 이들 작업점들을 통과, 포함하고, 또 기구학적으로 최적인 작업영역을 갖는 로봇팔을 설계하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제26권12호
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• pp.1663-1673
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• 2002

In the present paper, flow and heat transfer characteristics of confined impinging slot jets have been numerically investigated using a SIMPLE-based segregated SUPG finite element method. For laminar jets, it is shown that the skin friction coefficient obtained from the present SUPG formulation approaches the grid-independent Galerkin solution inducing negligible false diffusion in the flow field when a moderate number of grid points are used. For turbulent jets, the k-$\omega$turbulence model is adopted. The streamwise mean velocity and the heat transfer coefficient respectively agree very well with existing experimental data within limited ranges of parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.848-854
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• 2002

The nonlinear characteristics for the hinge of a deployable missile control fin are investigated experimentally. The nonlinearity is caused by a worn or loose hinge and manufacturing tolerance and cannot be eliminated completely. The structural nonlinearity has an effect on the static and dynamic characteristics of the control fin. Therefore, it is necessary to establish the accurate nonlinear model for the hinge of the control fin. In the present study the existence of nonlinearities in the hinge is confirmed from the frequency response experiments such as tip random excitation and base sine sweep. Using the system identification method, especially, “Force-State Mapping Technique”, the types of nonlinearities are identified and the nonlinear hinge model of the control fin is established.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제6권2호
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• pp.103-109
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• 1986

The distributions of fatigue life of concrete for various applied fatigue stress levels are investigated. The concrete beam specimens are tested in four-point flexural loading conditions. Three different levels of applied fatigue stresses are considered. They are 85%. 75%. 65%, respectively, of the static flexural strength of concrete. The present study indicates that the shapes of the probability distribution of fatigue lives are rather different for different levels of applied fatigue stress. This necessitates the consideration of the effects of applied fatigue stress levels on fatigue life distributions of concrete in order to conduct a realistic fatigue reliability analysis. The graphical method, the method of moments, and the method of maximum likelihood estimation are used to evaluate the distribution parameters of fatigue lives. It was found that the shape parameter of Weibull distribution for the fatigue life of concrete ranges from 2.0 to 4.0 according to the level of applied fatigue stress.