• 한국초전도ㆍ저온공학회논문지
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• 제15권1호
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• pp.14-18
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• 2013

We introduce a generic method to analyze optical 17reflectance spectra of strongly correlated electron systems including high-temperature superconductors by using an extended Drude model and Allen's approach. We explain the process step by step from reflectance through the optical conductivity and the scattering rate to the bosonic spectral function. Through the process we are able to get important information on the interactions between charge carriers from measured optical conductivity of the strongly correlated electron systems including copper oxide and iron pnitide high temperature superconductors.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.504-509
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• 2003

In this paper, a multi-step optimization using a G.A.(Genetic Algorithm) with variable penalty function is introduced to the structural design optimization of a high speed machining center. The design problem, in this case, is to find out the best cross-section shapes and dimensions of structural members which minimize the static compliance, the dynamic compliance, and the weight of the machine structure simultaneously. The first step is the cross-section shape optimization, in which only the section members are selected to survive whose cross-section area have above a critical value. The second step is a static design optimization, in which the static compliance and the weight of the machine structure are minimized under some dimensional constraints and deflection limits. The third step is a dynamic design optimization, where the dynamic compliance and the structure weight are minimized under the same constraints as those of the second step. The proposed design optimization method was successful applied to the machining center structural design optimization. As a result, static and dynamic compliances were reduced to 16% and 53% respectively from the initial design, while the weight of the structure are also reduced slightly.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.92-97
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• 2001

The major faults of CNC machine tool is operational error which is charge over 70%. This paper describes model of remote service and fault diagnosis for CNC machine tool with open architecture controller. For intelligent fault diagnosis, new model is proposed. In this paper, the three major operational faults, emergency stop error, cycle start disable and machine ready disable, are defined. Two diagnostic models based on the ladder diagram, switching function model, step switching function model, are proposed. For internet based remote service, suitable environment is proposed and implemented with web server and client.

• Journal of the Korean Statistical Society
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• 제26권4호
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• pp.507-520
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• 1997

In this paper we propose a robust Wald-type test which is based on an efficient Mallows-type one-step GM-estimator. The proposed estimator based on the weight function of Song, Park and Nam (1996) has a bounded influence function and a high breakdown point. Under some regularity conditions, we compute the finite-sample breakdown point, and drive asymptotic normality of the proposed estimator. The level and power breakdown points, influence function and asymptotic distribution of the proposed test statistic are main points of this paper. To compare the performance of the proposed test with other tests, we perform some Monte Carlo simulations.

• 정보처리학회논문지A
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• 제8A권1호
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• pp.42-47
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• 2001

In this paper, we present a curve fitting algorithm using a ball curve. Our algorithm is recursive method for fitting, which is not a traditional ball function but a continuous ball function. This algorithm consists of two steps. The first step, it is classified the composite corner points to joint points until selected from the given data set. The second step is the curve fitting. The basis function for curve fitting is use to ball function. Also, the weighted least square method, to insert knot, is an efficient method for piecewise ball curve and ball curve segments will be smoothly connected at all composit points. The proposed algorithm will be applied to represent image representation, like fonts, digital image and GIS.

• 생명과학회지
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• 제20권2호
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• pp.304-313
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• 2010

J시 소재 K여자고등학교 1학년 중에서 %fat이 30% 이상인 24명을 유의추출법에 의해 운동그룹 A (8명), B (8명) 그룹과 통제그룹(8명)으로 3그룹으로 구분하여 Borg의 주관적운동강도를 이용, A그룹은 RPE 15-17 (hard-very hard; 힘듦-매우 힘듦)${\times}$3 sets, B그룹은 RPE 11-13 (fairly light-somewhat hard; 알맞음-약간 힘듦)${\times}$3 sets로 설정하여 step aerobics (step box: 길이 68 cm, 폭 28 cm, 높이 15 cm, 무게 450 g)를 1일 50-60분간, 주3회(월, 수, 금)로 총 8주간 실시하였다. 본 연구는 step aerobics의 RPE가 비만 여고생의 면역기능(Neutrophil, Lymphocyte, Monocyte, Eosinophil, Basophil, IgG, IgA, IgM)에 어떠한 영향을 미치는가를 알아보는 것이었다. 자료처리는 SPSS Ver. 14.0을 이용하여 집단과 시기 간 상호작용의 효과를 알아보기 위하여 repeated two-way ANOVA를, 집단 내 운동 전 후는 paired t-test를 실시하였고, 집단 간은 변화율(% diff.)을 구하여 one-way ANOVA를 실시하여 다음과 같은 결론을 얻었다. WBC에서, 집단 내 비교에서 A그룹은 Neutrophil, Monocyte, Basophil, Eosinophil 모두 증가하였으나 Lymphocyte는 변화가 없었고, B그룹은 Eosinophil은 감소하였으나 Neutrophil, Lymphocyte, Monocyte, Basophil 모두 변화가 없었으며, 통제군은 Neutrophil, Basophil, Eosinophil은 감소하였으나 Lymphocyte와 Monocyte는 변화가 없었다. 집단 간 비교의 Neutrophil은 A그룹이 B그룹과 통제군보다 더 많이 증가하였고, Lymphocyte는 집단 간 차이가 없었으며, Monocyte는 A, B그룹이 통제군보다 많이 증가하였다. Basophil과 Eosinophil은 A그룹이 B그룹과 통제군보다 더 많이 증가하였다. Immunoglobin에서, 집단 내 비교에서 A그룹은 IgG는 증가하였으나 IgA와 IgM는 변화가 없었고, A그룹은 IgA는 증가하였으나 IgG는 감소하였고 IgM은 변화가 없었다. 통제군은 IgG은 감소하였으나 IgA와 IgM은 변화가 없었다. 집단 간 비교의 IgA는 A그룹이 통제군보다 증가하였고, IgG는 A그룹이 B그룹과 통제군보다 증가하였으나 IgM은 집단 간 차이가 없었다. 요약하면 세 집단 모두 운동프로그램 전 후의 WBC와 Ig 수준이 연령에 맞게 참고치 내의 수준에 머물렀지만 step aerobics를 RPE 15-17로 실시한 A그룹의 경우가 가장 많은 측정항목에서 증가를 보였고, 이 결과는 참고치 범위 내에서 면역기능의 항진을 보여주는 것으로 면역기능의 향상을 위한 step aerobics의 RPE 강도는 힘듦-매우 힘듦(15-17)의 수준으로 실시하는 것이 효과적인 것으로 생각된다.

• Structural Engineering and Mechanics
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• 제55권5호
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• pp.979-999
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• 2015

This paper proposes a novel reliability analysis method which computes reliability index, most probable point and probability of failure of uncertain systems more efficiently and accurately with compared to Monte Carlo, first-order reliability and response surface methods. It consists of Initial and Simulation steps. In Initial step, a number of space-filling designs are selected throughout the variables space, and then in Simulation step, performances of most of samples are estimated via interpolation using the space-filling designs, and only for a small number of the samples actual performance function is used for evaluation. In better words, doing so, we use a simple interpolation function called "reduced" function instead of the actual expensive-to-evaluate performance function of the system to evaluate most of samples. By using such a reduced function, total number of evaluations of actual performance is significantly reduced; hence, the method can be called Reduced Function Evaluations method. Reliabilities of six examples including series and parallel systems with multiple failure modes with truncated and/or non-truncated random variables are analyzed to demonstrate efficiency, accuracy and robustness of proposed method. In addition, a reliability-based design optimization algorithm is proposed and an example is solved to show its good performance.

• 한국항공우주학회지
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• 제44권9호
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• pp.814-824
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• 2016

본 논문에서 제안한 우주기반기술 검증용 큐브위성의 명칭은 STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project)으로 주요임무는 국내 산학연에서 기수행된 우주핵심기술을 발굴하며, 자체 개발 탑재체를 궤도 검증하는 것이다. 상기의 임무 구현을 위해 체계 레벨에서의 요구조건에 따라 전자조립 및 기능시험을 수행하였다. 또한, 비행 소프트웨어 설계의 유효성을 입증하였으며, 발사 궤도 열 환경시험을 통해 수락수준의 비행모델 검증을 완료하였다. 본 논문에서는 FM EIT, 발사 궤도 열 환경에서 수행한 기능시험의 일련 과정을 소개하고자 한다.

• 한국CDE학회논문집
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• 제4권4호
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• pp.295-311
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• 1999

An increasing attention is paid to STEP-NC, the next generation CNC controller interfacing STEP-compatible data. In this paper, we first propose an Architecture for the STEP-NC (called FBCC: Feature Baled CNC Controller) accepting feature code compatible with STEP-data, and executing NC motion feature by feature while monitoring the execution status. The main thrust of the paper has been to develop an automatic on-line tool path generation and modification scheme for milling operation. The tool path it generated iota each feature by decomposing into a finite number of primitive features. The key function in the new scheme is haw to accommodate unexpected execution results. In our scheme, the too1 path plinker is designed to have a tracing capability iota the tool path execution so that a new path can be generated from the point where the operation is stopped. An illustrative example is included to show the capability of the developed algorithm.

• 한국기계연구소 소보
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• 통권15호
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• pp.105-115
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• 1985

For the application of factory automation, a 3-axis numerical control system with personal computer and KM3701 function generator LSI chip, which has liner, circular, parabolic, logarithmic, and exponential interpolations, is developed. The developed system also has 2 control function to stabilize tooling speed and 1/1000mm step sizes.