• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.9-11
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• 2000

전형적인 단순 유전자 알고리즘은 한 개의 모집단으로 구성되며, 진화 과정이 거듭되면 모집단의 개체들은 한 개의 전역해로 수렴하게 된다. 그러나, 많은 문제들은 여러 개의 최적해를 가질 수 있으며, 그것들 모두를 찾는 것이 중요한 경우가 많다. 이 논문에서는 모집단을 원환체(Torus)로 구성하고 개체에 이웃의 개념을 부여하여 모집단이 최적해 집단으로 수렴하는 유전자 알고리즘의 변형을 연구한다. 제안한 방법은 개체사이에 이웃이라는 개념을 부여함으로써 다수의 해를 동시에 찾는다는 생각을 넘어서 다양한 변형 유전자 알고리즘에 대한 새로운 모델이 될 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.945-946
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• 2015

Laser Range Finder를 이용하여 생성한 3차원 점군 정보는 단면적인 부분만 볼 수 있으며, 잡음이 포함되어 작은 물체를 추출하는데 많은 영향이 생긴다. 이러한 잡음이 있는 3차원 점군 정보 사이에서 밸브의 중심의 위치에 대한 추가적인 입력을 받아 원환체, 원통, 평면의 정보를 복합적으로 포함하고 있는 밸브의 모델을 추출한다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.139-142
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• 2004

The fabric composite rings for nozzle parts of solid rocket motors should be thick to endure high temperature and pressure of combustion gas. Since the thermal residual stresses developed during manufacturing of the axi-symmetric composite structures increase as the thickness increases and eventually induce failures during storage and operation, the estimation of the residual stresses is indispensable for design and manufacture of the thick composite nozzle parts. In this paper, thick fabric rings made of carbon fabric phenolic composites were fabricated in a hydroclave and in an autoclave using a multi-step pre-compaction process to minimize draping. The residual stresses distributed in the rings were measured by the radial-cut method and it was found that the compaction reduces the residual stresses in the composite ring.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.62-65
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• 2006

In this paper, nonlinear nonplanar vibration of a flexible rectangular cantilever beam is analyzed when one-to-one resonance occurs to the beam. The planar and nonplanar motions of the beam are analyzed in time and frequency domains. In frequency domain, FFT analyzer is used to perform autospectrum and cepstrum analyses for nonlinear response of the beam. In time domain, an oscilloscope is used to investigate the phase difference between the planar and nonplanar motions and to perform Torus analysis in the phase space. Through those analyzing process, the main frequencies of superharmonic, subharmonic, and super-subharmonic motions are investigated in the nonplanar motion due to one-to-one resonance. Analyzing the phase difference between the planar and nonplanar motions, it is observed that the phase difference varies in time.

• 전기의세계
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• v.45 no.7
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• pp.12-17
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• 1996

핵융합 반응을 일으키기 위한 조건으로써는 핵융합 연료를 초 고온 (1억도 이상)의 플라즈마 상태로 그 밀도와 밀폐(반응)시간의 곱이 $10^{20}$sec/m$^{3}$ 이상에 도달하도록 핵융합 반응 공간내에 밀폐시켜야 한다[1]. 현재까지의 밀폐방식으로는 강력한 전자석의 전자력을 이용하는 자계 밀폐방식 (Magnetic Confinement)과 레이져등을 이용하는 관성 밀폐 방식(Inertial Confinement)이 있다. 강력한 자장 발생이 용이한 특징을 지닌 초전도자석이 요구되는 자계 밀폐방식에도 여러가지 방식이 있으나, 크게 분류해 보면 원환체 (Torus)상의 자장을 발생시키는 토러스 밀폐방식과 직선상의 자장을 발생시키는 개방형 밀폐방식으로 대별되며 그 중에서도 핵융합 반응을 일으키기 위한 조건에 가장 근접한 플라즈마를 실현시키고 있는 토러스 밀폐방식의 일종인 토카막(Tokamak) 핵융합장치용 초전도자석에 대해 고찰한다.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.183-191
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• 2010

The phase changes of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) bilayers distorted by an antimicrobial peptide, a magainin 2 or an aurein 3.3 were investigated by using $^2H$ solid-state NMR (SSNMR) spectroscopy. From the theoretical simulation of the experimental $^2H$ solid-state NMR spectra the geometric structure constants and the lateral diffusion coefficients were obtained in the peptide-lipid mixture phases. Within five days of the peptide action on the lipid bilayers only the distorted alignment of the bilayers were measured but after 100 days an elliptic toroidal pore structure and an inverted hexagonal phase were formed in the presence of magainin 2 and aurein 3.3, respectively. In order to investigate the effect of an anionic lipid molecule on the actions of two peptides on the lipid bilayer, the same experiments were performed on the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) bilayer and the significant differences in the actions of two peptides on two bilayers of POPC_$d_{31}$ and POPC_$d_{31}$/POPG were measured.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.77-86
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• 2015

It is difficult to extract small valve automatically in noisy 3D point cloud obtained from LIDAR because small object is affected by noise considerably. In this paper, we assume that the valve is a complex model consisting of torus, cylinder and plane represents handle, rib and center plane to extract a pose of the valve. And to extract the pose, we received additional input: center of the valve. We generated histogram of distance between the center and each points of point cloud, and obtain pose of valve by extracting parameters of handle, rib and center plane. Finally, the valve is reconstructed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.690-695
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• 2005

Flexible circular cantilever beams when excited externally introduce a lot of dynamic characteristics. The non-linear elements that these flexible beams develop include non-linearity due to inertia terms, spring, and damping. They show different characteristics of motion from each other. In the modes of lower order, the non-linearity due to spring is prevalent, while the non-linearity due to inertia Is prevalent in the modes of higher order. To analyze these effects the non-linear phenomena are analyzed experimentally. When the response characteristics of non-linear vibration are analyzed using autospectrum, it is possible to analyze the subharmonic and superharmonic mot ion by comparison. The phase change is analyzed using the method of phase portrait and the non-linear characteristics of response characteristics that are developed in flexible structures can be predicted and applied to the stage of design.

• Analytical Science and Technology
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• v.26 no.1
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• pp.61-66
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• 2013

The activity of an antimicrobial peptide, protegrin-1, on the well-aligned lipid bilayer deposited on a thin coverglass plate was investigated by $^2H$ solid-state NMR spectroscopy. Orientational distribution and molecular motion in the lipid bilayer were determined from $^2H$ solid-state NMR spectrum. Reorientational motion of lipid molecules in the vacuum-dried state was found to be small but their orientational distribution was not able to be determined. As storage times were longer, the order of the alignment of lipid molecules in the lipid bilayer and percentages involved in the toroidal pore structures increased. We found that much longer time is required to get the equilibrium state of the peptide-lipid mixture under our experimental condition for investigating the action of the antimicrobial peptide like protegrin-1 on the lipid bilayers deposited on the thin coverglass plates.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.81-85
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• 2006

Through-the-thickness properties of thick-walled cylindrical composites are required to determine structural performances because interlaminar tensile stress is primarily responsible for structural failure of the composites during their curing process. It is necessary for evaluating the tensile properties to find individual test methods to find appropriate methods because there are no recognised international standards(test methods and test specifications) available for generating reliable tensile properties in the direction. This paper has performed an experimental Study to measure that properties of carbon fabric/phenolic composites are produced by domestic company. Several test methods using an aluminum specimen were compared and evaluated. The best method, found out, was adopted to measure transverse through-the-thickness properties of composite materials. The results show that strain trends on four faces of composite specimen are the same.