• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.9-10
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• 2006

A numerical method for simulating tree surface flows including the surface tension is presented. Numerical scheme is based an a fractional-step method with a finite volume formulation and the interface between liquid and gas is tracked by Volume of Fluid (VOF) method. Piecewise Linear Interface Calculation (PLIC) method is used to reconstruct the interface and the surface tension is considered using a Continuum Surface Force (CSF) model. Several free surface flow phenomena were simulated to show its effectiveness to find such phenomena.

• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.221-227
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• 2006

본 연구는 경북에 소재한 식품회사인 S사의 햄 생산공정의 개선을 위하여 통계적 공정관리기법을 적용한 것이다. 햄의 중량은 햄의 품질에 대한 소비자의 신뢰와 기업의 수익성에 영향을 미치는 풍요한 요소이다. 연구의 목적은 햄 생산공정의 경제적 규격한계 확보를 통하여 기업의 이익을 극대화하는데 있나. 기본적인 통계적 공정관리 기법인 평균-범위 관리도, 공정능력분석, 측정시스템 평가분석 등을 이용하여 햄 공정을 분석하고, 최적 규격한계를 설정하였다.

• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.152-162
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• 1999

In this paper we develope a new nonparametric estimator of the reliability in strength-stress model. This estimator is constructed using the maximum likelihood estimate of cumulative failure rate in the class of distributions which have piecewise linear failure rate functions between each pair of observations. Large sample properties of our estimator are examined. The proposed estimator is compared with previously known estimator by Monte Carlo study.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1882-1885
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• 2002

This paper shows design of maximal-period sequences with prescribed constant auto-correlation values based on one-dimensional (1-D) maps with (mite bits. We construct such 1-D maps based on piecewise linear onto chaotic maps. Theoretical analyses and some design examples are given.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.174-181
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• 2000

A brief review of previous studies on the behaviour of concrete at extremely low temperature is presented in this paper. In addition, to describe temperature dependent behaviour of concrete, simple piecewise linear stress-strain relation is introduced. The proposed curve shows good agreement with experimental stress-strain curves at various temperature conditions. Moreover, numerical analyses for two PC beams are conducted to verify the influence of extremely low temperature to the structural behaviour.

• 전기의세계
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• v.28 no.1
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• pp.53-58
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• 1979

In the microwave heating system, a ferroresonant transformer is used to regulate the magnetron power fluctuation. For the simplification, nonlinear characteristics of the transformer and the magnetron are idealized to be piecewise linear. Dipped peak shape of the magnetron current is explained qualitatively by considering the fundamental and third harmonic frequency components in the circuit. Design equations providing the values of the leakage inductance, turn ratio of the transformer and the capacitance are derived analytically by cosnidering the fundamental frequency component only. The ferroresonant transformer is designed to obtain a required regulation and high input power factor from the derived design equations, and analytical calculations are compared with experimental measurements.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2348-2350
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• 2005

LHM (Left Handed Material)은 특정 주파수 범위에서 음의 유전율과 투자율을 가지는 물질이며 유효 유전율과 투자율은 분산 특성을 가지고 로렌츠(Lorentz) 물질과 비슷한 형태를 가진다. 본 논문에서는 FDTD (Finite Difference Time Domain) 법을 바탕으로 한 PLRC (Piecewise Linear Recursive Convolution) 법을 이용하여 LHM 내의 유효 전파특성을 모의한다. 모의실험 결과는 음의 유전율과 투자율을 가지는 주파수 범위를 보여준다.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.501-503
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• 1993

A circuit of sigmoid function for neural network is designed by using Piecewise Linear (PWL) method. The slope of sigmoid function can be adjusted to 2 and 0.25. Also the circuit presents both sigmoid function and its differential form. The circuits is simulated by using ViewLogic. Theoretical and simulated performance agree with 1.8 percent.

• Journal of Korean Society for Quality Management
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• v.27 no.1
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• pp.91-100
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• 1999

In this paper we propose a smooth nonparametric estimator of mean residual life based on a complete sample. This estimator is constructed using the maximum likelihood estimate of cumulative failure rate in the class of distributions which have piecewise linear failure rate functions between each pair of observations. We derive the asymptotic properties of our estimator. Examples using simulated data are used to illustrate the performance of this estimation.

• Communications of the Korean Mathematical Society
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• v.18 no.4
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• pp.767-779
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• 2003

We consider a model of population dynamics whose mortality function is unbounded. We approximate the solution of the model using a discontinuous Galerkin finite element for the age variable and a backward Euler for the time variable. We present several numerical examples. It is experimentally shown that the scheme converges at the rate of $h^{3/2}$ in the case of piecewise linear polynomial space.