• 대한기계학회논문집B
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• 제30권3호
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• pp.270-277
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• 2006

Inverse radiation problems were solved for estimating boundary temperature distribution in a way of function estimation approach in an axisymmetric absorbing, emitting and scattering medium, given the measured radiative data. In order to reduce the computational time fur the calculation of sensitivity matrix, automatic differentiation and Broyden combined method were adopted, and their computational precision and efficiency were compared with the result obtained by finite difference approximation.. In inverse analysis, the effects of the precision of sensitivity matrix, the number of measurement points and measurement error on the estimation accuracy had been inspected using quasi-Newton method as an inverse method. Inverse solutions were validated with the result acquired by additional inverse methods of conjugate-gradient method or Levenberg-Marquardt method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1288-1293
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• 2004

Inverse radiation problems are solved for estimating the boundary conditions such as temperature distribution and wall emissivity in axisymmetric absorbing, emitting and scattering medium, given the measured incident radiative heat fluxes. Various regularization methods, such as hybrid genetic algorithm, conjugate-gradient method and Newton method, were adopted to solve the inverse problem, while discussing their features in terms of estimation accuracy and computational efficiency. Additionally, we propose a new combined approach of adopting the genetic algorithm as an initial value selector, whereas using the conjugate-gradient method and Newton method to reduce their dependence on the initial value.

• 대한기계학회논문집B
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• 제29권8호
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• pp.903-910
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• 2005

Inverse radiation problems are solved for estimating the boundary conditions such as temperature distribution and wall emissivity in axisymmetric absorbing, emitting and scattering medium, given the measured incident radiative heat fluxes. Various regularization methods, such as hybrid genetic algorithm, conjugate-gradient method and finite-difference Newton method, were adopted to solve the inverse problem, while discussing their features in terms of estimation accuracy and computational efficiency. Additionally, we propose a new combined approach that adopts the hybrid genetic algorithm as an initial value selector and uses the finite-difference Newton method as an optimization procedure.

• 대한기계학회논문집B
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• 제38권9호
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• pp.747-755
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• 2014

광자(Photon)이나 전자기파(Electromagnetic Wave) 등의 형태로 직접 열을 전달하는 특징을 가지고 있는 복사열전달은 중간 매질의 열전달 관여여부에 따라 표면복사(Surface Radiation)와 기체복사(Gas Radiation)의 형태로 구분될 수 있다. 본 연구에서는 원통 형상에서의 표면복사에 대해 미지의 복사물성치들을 역해석 방법을 이용해 역추정하였다. 이때, 효율적인 역해석을 위해 반발 입자 군집 최적화(Repulsive Particle Swarm Optimization, RPSO) 알고리즘을 역해석 기법으로 채택하였다. 이로부터 얻은 해의 수렴성과 정확도 등을 기존의 유전알고리즘(GA) 결과와 비교해 봄으로써, 표면복사 현상에 대한 역해석의 적용 가능성을 고찰하고자 하였다.