• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.359-372
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• 2000

Current CAD systems are good enough to be used as a tool to manipulate three-dimensional shapes. This is a very important capability to be owned by a design tool because a major portion of designers'activities is spent on the shape manipulation in the design detailing process. However, the whole design process involves a lot more than the, shape manipulation. Currently, these remaining tasks, mostly logical reasoning process for the function realization together with structure decomposition in the top-down manner, are processed in the designer's brain. To support the top-down functional design process of a mechanical product, a system integrating the functional, structural and geometrical aspects of a product design in a unified environment is presented. Using this system, a designer can perform function decomposition, structure decomposition, and geometry detailing, and function verification activities in parallel and the whole design process it modeled resultantly. Once the whole design process is modeled, any redesign task can be automatically performed with the verification of the desired functions.

• The Korean Journal of Food And Nutrition
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• v.3 no.2
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• pp.123-132
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• 1990

Sweet potato $\beta$-amylase is a tetrameric enzyme consisting of four identical polypeptide chains with a molecular weight of 5.6$\times$104, though most of the other $\beta$-amylases are monomeric enzymes. But, the relationship between subunit structure and catalytic function of the enzyme is not known. This study was done to know what the function of the subunit structure of the enzyme is. We obtained the monomer from the enzyme by the treatment of SDS, alkali pH buffer and urea. But the monomer had not activity. We tried to prepare the active monomer from the enzyme by the modification with periodate-oxidized soluble starch , In the result, we succeeded in isolating an active monomer as an oxidized soluble starch-conjugated form The active monomer had 57% of the original activity, 13.2% of the sugar and the molecular weight was estimated to be 5.4$\times$104. This results suggest that the tetrameric form of the enzyme is a most stable one and exists in nature, and the subunit structure of the enzyme Plays an important role in stabilization but not catalytic function.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.2
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• pp.126-132
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• 2012

The technique for estimation of sound source direction is one of the important methods necessary for various engineering fields such as monitoring system, military services and so on. As a new approach for estimation of sound source direction, this paper propose the bio-mimetic localization sensor based on mechanically coupling structure motivated by hearing structure of fly, Ormia Ochracea. This creature is known for its outstanding recognition ability to the sound which has large wavelength compared to its own size. ITTF (Inter-Tympanal Transfer Function) which is the transfer function between displacements of the tympanal membranes on each side has the all inter-tympanal information dependent on sound direction. The peak and notch features of desired ITTF can be generated by using the appropriate mechanical properties. A example of estimation of sound source direction using generated ITTF with monotonically changing notch and peak patterns is shown.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.151-156
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• 2007

2006년부터 VE 대상프로젝트가 확대되고, 기본설계와 실시설계단계에 각 1회씩 설계VE를 적용토록 규정되어 설계단계별로 VE가 각각 적용되는 프로젝트가 늘어나고 있다. 그리고 원가절감과 성능향상으로 프로젝트 가치를 높인 설계VE 사례도 많아지고 있다. 하지만 기본설계와 실시설계단계의 조건에 적합한 VE 수행방안에 대한 연구가 미진하고 참여자들의 경험과 이해가 부족하여 단계별 설계VE를 효율적으로 수행하는데 많은 어려움이 있다. 본 연구에서는 기본설계단계와 실시설계단계로 나누어 VE를 수행한 실무사례를 분석하여 기능정의와 아이디어 창출간의 연관관계 및 각 설계단계에서 기능정의를 수행할 때 발생하는 문제점을 도출하였다. 문제점을 해결하고 효과적인 설계VE를 수행하기 위하여 다음과 같은 개선방안을 제시하였다. 첫째, 설계프로세스의 흐름에 맞추어 기본설계에는 공간기능에 대하여하고 실시설계에는 부위에 대하여 기능정의를 수행한다. 이때 상위의 레벨에는 하위의 레벨의 기능정의가 연계되는 기능분류체계 (FBS : Function Breakdown Structure)를 제안하였다. 둘째, 기본설계와 실시설계단계의 기능정의를 수행하는 프로세스 (FDP : Function Definition Process)를 제안하였다. 셋째, 실시설계단계에서는 부위별 요구 성능 평가 매트릭스 (EFM : Element Function Matrix)를 적용하여 기능정의와 아이디어 창출이 연계되도록 하였다. 설계VE의 주요 부분인 기능정의 과정에 대한 문제점을 도출하여 해결방안을 제시함으로써, 보다 효과적인 설계VE의 수행을 기대할 수 있다.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.53-62
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• 2017

Many gradient-based mathematical methods have been developed and are in use for structural size optimization problems, in which the cross-sectional areas or sizing variables are usually assumed to be continuous. In most practical structural engineering design problems, however, the design variables are discrete. The main objective of this paper is to propose an efficient optimization method for structures with discrete-sized variables based on the harmony search (HS) meta-heuristic algorithm that is derived using penalty function. The recently developed HS algorithm was conceptualized using the musical process of searching for a perfect state of harmony. It uses a stochastic random search instead of a gradient search so that derivative information is unnecessary. In this paper, a discrete search strategy using the HS algorithm with a static penalty function is presented in detail and its applicability using several standard truss examples is discussed. The numerical results reveal that the HS algorithm with the static penalty function proposed in this study is a powerful search and design optimization technique for structures with discrete-sized members.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.162-163
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• 2013

A temporary work are lifting equipment that tower crane or lift, and temporary architectures that office building and storage in construction site. And it is main construction work that built and used temporarily like to a scaffolding, a walk plate, and a formwork. This study is to adjust breakdown structure of temporary work to introduce technical tendency. With a site manager, it is collected a detailed statement and compared. As a result to break down a tendency that temporary equipment, additional function, and direct work of temporary technique, first, existing detail technical indexes that group I, group J, group K, and group L are classified. Second, due to set up and manage to main agents in case of existing detail technical indexes that B1, B2, it is not wrong to classify. But, it is somewhat different, and therefore adjust it to same level. Finally, as a technical tendency that temporary equipment, additional function, and direct work of temporary technique, it is adjusted the others.

• Structural Engineering and Mechanics
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• v.65 no.1
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• pp.111-120
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• 2018

This paper presents a new and simple solution for determining the natural frequencies of framed tube combined with shear-walls and tube-in-tube systems. The novelty of the presented approach is based on the bending moment function approximation instead of the mode shape function approximation. This novelty makes the presented solution very simpler and very shorter in the mathematical calculations process. The shear stiffness, flexural stiffness and mass per unit length of the structure are variable along the height. The effect of the structure weight on its natural frequencies is considered using a variable axial force. The effects of shear lag phenomena has been investigated on the natural frequencies of the structure. The whole structure is modeled by an equivalent non-prismatic shear-flexural cantilever beam under variable axial forces. The governing differential equation of motion is converted into a system of linear algebraic equations and the natural frequencies are calculated by determining a non-trivial solution for the system of equations. The accuracy of the proposed method is verified through several numerical examples and the results are compared with the literature.

• The Mathematical Education
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• v.53 no.1
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• pp.25-40
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• 2014

Mathematical concept exists in the structural form, not in the independent form. The purpose of this study is to consider the network which students actually have for the mathematical concept structure related to the properties of derivatives. First, we analyzed the properties of derivatives in 'Mathematics II' and showed the mathematical concept structure of the relations among derivatives, functions, and primitive functions as a network. Also, we investigated the understanding of high school students for the mathematical concept structure between derivatives and functions, and the structure between functions and second order derivatives when the functional formula is not given, and only the graph is given. The results showed that students mainly focus on the relation of 'function-derivatives', the thinking process for direction of derivative and the thinking style for algebra. On this basis, we suggest the educational implication that is necessary for students to build the network properly.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.227-230
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• 2007

The multi-lamellar and liquid crystal structures have drawn great public attention in the functional cosmetic and skin-related medicinal areas recently. The structure of an emulsion containing aqueous phase as a binding water and fixed oil phase components forming an association compound of the multi-lamellar structure can reconstruct the intercellular lipid lamellar structure in the stratum corneum and restore barrier function of the skin. In this study, we investigated the beneficial effect of bio-mimic liquid crystal emulsions (BLCE) containing higher fatty alcohol, lecithin, and cholesterol on the skin barrier function, and evaluated its cytotoxicity.

• Journal of The Korean Association For Science Education
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• v.23 no.1
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• pp.1-8
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• 2003

The purpose of present study was to develop teaching-learning materials based virtual reality technology(VRT), and to examine the effect of it on the knowledge achievement of biology. Authoring tool of virtual reality(VR) was 3D Webmaster made in Superscape Ltd., United Kingdom. Educational materials was developed for the structure and function of eye of life field in the 10th science. It was learner-directed and interactive educational material using the Web-based and desktop VR. The result showed a meaningful improvement on the achievement. Using 3D VR shows the potential of available education media in the next generation as science teaching-aided materials, which especially was efficient in the understanding and perception of abstract or difficult to direct experience learning contents.