• Nonlinear Functional Analysis and Applications
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• 제26권4호
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• pp.811-837
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• 2021

In this paper, we propose a new conjugate gradient method for solving unconstrained optimization models. By using exact and strong Wolfe line searches, the proposed method possesses the sufficient descent condition and global convergence properties. Numerical results show that the proposed method is efficient at small, medium, and large dimensions for the given test functions. In addition, the proposed method was applied to solve practical application problems in portfolio selection.

• Journal of the Optical Society of Korea
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• 제3권2호
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• pp.47-50
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• 1999

Nonlinear optical properties of an unsaturated polymer (poly trifluroethy dipropargy malonate) are investigated by using a passive Q-switched Nd:YAG laser. Double-peaked structure of phase conjugate signals due to the two-photon-absorption induced thermal effect is clearly is clearly observed and a simple method to remove the thermal effect from the overall phase-conjugate signals is demonstrated.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제5권2호
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• pp.17-23
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• 2001

The evaluation of a few of the smallest eigenpairs of large symmetric eigenvalue problem is of great interest in many physical and engineering applications. A deflation-preconditioned conjugate gradient(PCG) scheme for a such problem has been shown to be very efficient. In the present paper we provide the numerical stability of a deflation-PCG with partial shifts.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.29-36
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• 2003

Exhaust manifolds suffer from serious temperature variation during the thermal fatigue test. The spatial distribution of temperature changes at each moment. Because transient flow can not be simulated during the long period of temperature change, the simulation can not be performed by conjugate heat transfer analysis. In this study, a new procedure for transient thermal analysis is established by decoupling fluid-solid analysis. The procedure consists of (1) transient CFD calculation (2 cycles), (2) mapping heat transfer coefficient to the inner surface of solid mesh as a boundary condition of heat conduction analysis and (3) transient heat conduction analysis in the long period (30 min). The realistic temperature change can be predicted by this procedure.

• 한국콘텐츠학회논문지
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• 제20권6호
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• pp.1-8
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• 2020

빅데이터 분석에서 텍스트 데이터의 활용이 증가하고 있다. 따라서 텍스트 데이터의 분석 기법에 관한 많은 연구가 이루어지고 있다. 본 논문에서는 텍스트 데이터로부터 추출된 키워드 데이터의 분석을 위하여 공액사전분포 기반의 베이지안 학습 방법이 연구된다. 베이지안 통계학은 기존의 데이터에 새로운 데이터가 추가될 때마다 모수를 갱신하는 데이터 학습을 제공하기 때문에 시간에 따라 대용량의 데이터가 생성 및 추가되는 빅데이터 환경에서 효율적인 방법을 제공한다. 제안 방법의 성능과 적용 가능성을 보이기 위하여 실제 특허 빅데이터를 전처리하여 구축된 정형화된 키워드 데이터를 분석하는 사례연구를 수행한다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.488-493
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• 2011

The object of this study is to develope the program for analyzing the fluid flow and heat transfer of PMSM electric motor. The program will be mainly used for inexperienced users of CFD analysis. So it has to be performed using the geometry data and the heat source of each part only. Interface program for converting the given data to the instruction of pre-processor is developed. The conjugate heat transfer between a flow passage of the motor and inner parts consisting of rotor and stator is regarded. In order to reduce the computational time and memory storage, cyclic boundary condition is applied. For the numerical simulation, MRF(Multi-Reference Frame) method is used to consider rotating operation of the rotor and heat source is applied to the copper, wire, and magnetic parts in the motor. On the screen of computer, the users can show the velocity distributions and the contours such as pressure, turbulent kinetic energy, turbulent dissipation rate and temperature.

• 한국전산유체공학회지
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• 제18권1호
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• pp.77-82
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• 2013

The error in measuring temperature profiles by thermocouple inside boundary layer mostly comes from the conduction heat transfer of the thermocouple. The error is not negligible when the conductivity of the thermocouple is very high. In this study, the effect of conduction heat transfer of the thermocouple on the temperature profile inside boundary layer was examined by considering both free-stream velocity and a thermocouple position. The conduction error of an E-type thermocouple was investigated by numerical analysis of three-dimensional conjugate heat transfer for various velocity profiles of boundary layer and thermocouple positions.

• 한국군사과학기술학회지
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• 제21권1호
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• pp.74-85
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• 2018

This study has analyzed the convective heat transfer on the deck exposed to the high-temperature impingement exhausting from a VTOL vehicle. The heat flow of the impingement on the deck is modeled by the convection heat transfer. The convective heat flux generated by the hot impinging jet is investigated by using both convective heat transfer formulation and conjugate heat transfer formulation. Computational fluid dynamics(CFD) code was used to compute the heat flux distribution. The RANS equation and the k-e turbulence model were used to analyze the thermal flow of the impinging jet. The heat flux distribution near the stagnation zone obtained by the conjugate heat transfer analysis shows more reasonable than the convective heat transfer analysis.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.149-152
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• 2011

A new chemiluminescence immunochromatographic analysis system with high sensitivity and high reproducibility was developed for the determination of microcystins (MCs) in water. Horse radish peroxidase (HRP) labeled microcystin monoclonal antibody was used for the sensitive chemiluminescence detection. The chemiluminescence immunochromatographic analysis system was composed of microcystin LR (MCLR)-monoclonal antibody (mAb)-Horse Radish Peroxidase (HRP) conjugate, MCLR-BSA conjugate, luminol, hydrogen peroxide mixture solution, an immunochromatographic assay strip and luminometer. To detect the concentration of microcystins in water, we utilized one spot analysis of the strip instead of flow type analysis. We could detect the microcystins in water at a concentration as low as 9.45 pg/mL with the chemiluminescence (CL) detection.

• 한국환경농학회지
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• 제11권1호
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• pp.59-66
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• 1992

Endosulfan을 복잡한 시료조제과정이 필요치 않는 ELISA기법으로 분석법을 정립하고자 하였다. 항원조제를 위한 endosulfan alcohol의 합성은 86%의 수율을 보였고 endosulfan hemisuccinate는 HPLC로 그 합성을 확인하였다. Endosulfa-hemocyanin(KLH) 결합체의 수율은 3.57mg/ml였으며 이 항원은 1.1mg/ml로 희석하여 토끼에 대해 피하주사로서 면역시켰고 8주 후에 채혈된 항체 용액은 indirect ELISA로 1 : 24,000의 역가를 결정하였다. 또한 endosulfan-peroxidase 결합체는 약 40%의 결합수율인 2mg/ml로 조제되었으며 이 결합체는 높은 흡광도와 민감도를 나타내는 200ng/ml의 농도로 사용하였다. ELISA 분석에 의한 endosulfan의 검출한계는 5 ppb였으며 분해산물인 endosulfan ether와 endosulfan alcohol의 endosulfan 항체에 대한 민감도는 각각 57.14%, 105.20%였다. 유사한 유기염소계 농약들에 대한 교차반응성은 captan이 2.2%로 가장 낮게 나타났고 Captafol이 29.33%로 가장 높게 나타났다. ELISA에 의한 잔류 분석을 토양과 사과에서 응용 시험한 결과 토양에서는 10 ppb와 100 ppb에서 각각 97.45%, 98.40%의 회수율을 보였고 사과에서는 각각 98.40%, 100.55%의 회수율을 나타냈다.