• 한국지능시스템학회논문지
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• 제23권1호
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• pp.72-79
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• 2013

본 논문에서는 태양광 발전시스템의 최대전력점을 추종하기 위해, 개방회로전압과 가까운 첫 번째 지역극대전력점(local peak power point)의 전압 및 전류값이 특정한 범위 내에 있을 경우, 첫 번째 지역극대점이 전역극대전력점(global peak power point)인지 판단할 수 있도록 패턴을 분석하였다. 직-병렬 어레이로 연결된 태양전지 모듈에 부분그늘문제(partial shading problem)가 발생할 경우 다수의 지역극대전력점이 관찰될 수 있어, 전역극대전력점을 찾는데 어려움이 있다. 부분선형 태양전지 모델을 이용한 태블로 해석(Tableau analysis)으로 태양전지 어레이 회로의 V-I 특성을 시뮬레이션하여 지역극대전력점과 전역극대전력점을 확인하고, 그에 해당하는 전압 및 전류 값과 V-I 특성곡선의 패턴을 분석하였다. 분석된 패턴을 통해 특정한 영역을 설정하여 첫 번째 지역극대전력점이 전역극대전력점 인지 판단하여 발전하는 경우, 첫 번째 지역극대전력점으로만 발전했을 때에 비해 효율이 향상되었다.

• International Journal of Control, Automation, and Systems
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• 제2권2호
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• pp.201-206
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• 2004

Counters for the various kinds of banknotes require high-speed distinctive point extraction and recognition. In this paper we propose a new point extraction and recognition algorithm for Euro banknotes. For distinctive point extraction we use a coordinate data extraction method from specific parts of a banknote representing the same color. To recognize banknotes, we trained 5 neural networks. One is used for inserting direction and the others are used for face value. The algorithm is designed to minimize recognition time by using a minimal amount of recognition data. The simulated results show a high recognition rate and a low training period. The proposed method can be applied to high speed banknote counting machines.

• 경영과학
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• 제21권2호
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• pp.43-60
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• 2004

Every iteration of interior-point methods of large scale optimization requires computing at least one orthogonal projection. In the practice, symmetric variants of the Gaussian elimination such as Cholesky factorization are accepted as the most efficient and sufficiently stable method. In this paper several specific implementation issues of the symmetric factorization that can be applied for solving such equations are discussed. The code called McSML being the result of this work is shown to produce comparably sparse factors as another implementations in the $MATLAB^{***}$ environment. It has been used for computing projections in an efficient implementation of self-regular based interior-point methods, McIPM. Although primary aim of developing McSML was to embed it into an interior-point methods optimizer, the code may equally well be used to solve general large sparse systems arising in different applications.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.173-176
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• 2006

The one of the commonly reported failure mode of the RC beam strengthened with FRP was caused by the separation of the concrete cover, so called delamination. Therefore, ACI440 recommended that concrete cover delamination can be prevented in strengthened beams if bond length of FRP composite be exteneded over a point of cracking moment. In this study, the failure mode and the flexural performance of RC beam with different bond length of FRP are estimated. Each bonded length is calculated based on the point of cracking moment with addition or subtraction of specific length(=150mm). The results of this study show that mid-span debonding occurs in the specimen strengthened with CFRP strips which are bonded over the point of cracking moment, while concrete cover deliamination occurs at the termination point of CFRP in the specimen with less bonded length than the point of cracking moment region.

• The Korean Journal of Pain
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• 제24권1호
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• pp.57-60
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• 2011

Pulsed radiofrequency (PRF) treatment of nervous tissue has been proposed as a less neurodestructive technique alternative to continuous RF heat lesioning. Recently, clinical reports using PRF have shown favorable effects in the treatment of a variety of focal pain areas, even in non-nervous tissues; however, the mechanism of effect underlying this treatment to non-nervous tissue remains unclear. We report the case of a 67-year-old male who presented with pain reliving point in the posterior neck. The patient had pain in the posterior neck for 3 years. The pain subsided with pressure applied to a point in the posterior neck. There were no specific abnormal findings on laboratory testing and radiologic examinations. After PRF treatment to the pain-relieving point, he had pain relief which lasted more than 5 months.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제11권4호
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• pp.69-88
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• 2007

In this paper we propose new large-update primal-dual interior point algorithms for $P_{\neq}({\kappa})$ linear complementarity problems(LCPs). New search directions and proximity measures are proposed based on a specific class of kernel functions, ${\psi}(t)={\frac{t^{p+1}-1}{p+1}}+{\frac{t^{-q}-1}{q}}$, q>0, $p{\in}[0,\;1]$, which are the generalized form of the ones in [3] and [12]. It is the first to use this class of kernel functions in the complexity analysis of interior point method(IPM) for $P_*({\kappa})$LCPs. We showed that if a strictly feasible starting point is available, then new large-update primal-dual interior point algorithms for $P_*({\kappa})$ LCPs have the best known complexity $O((1+2{\kappa}){\sqrt{2n}}(log2n)log{\frac{n}{\varepsilon}})$ when p=1 and $q=\frac{1}{2}(log2n)-1$.

• International Journal of Air-Conditioning and Refrigeration
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• 제13권4호
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• pp.206-216
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• 2005

Numerical analysis has been carried out to investigate laminar convective heat transfer at zero gravity in a tube for supercritical water near the thermodynamic critical point. Fluid flow and heat transfer are strongly coupled due to large variation of thermodynamic and transport properties such as density, specific heat, viscosity, and thermal conductivity near the critical point. Heat transfer characteristics in the developing region of the tube show transition behavior between liquid-like and gas-like phases with a peak in heat transfer coefficient distribution near the pseudo critical point. The peak of the heat transfer coefficient depends on pressure and wall heat flux rather than inlet temperature and Reynolds number. Results of the modeling provide convective heat transfer characteristics including velocity vectors, temperature, and the properties as well as the heat transfer coefficient. The effect of proximity on the critical point is considered and a heat transfer correlation is suggested for the peak of Nusselt number in the tube.

• Structural Engineering and Mechanics
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• 제70권6호
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• pp.711-722
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• 2019

Considering stress singularities at point support locations, buckling solutions for plates with arbitrary number of point supports are hard to obtain. Thus, new Hp-Cloud shape functions with Kronecker delta property (HPCK) were developed in the present paper to examine elastic buckling of point-supported thin plates in various shapes. Having the Kronecker delta property, this specific Hp-Cloud shape functions were constructed through selecting particular quantities for influence radii of nodal points as well as proposing appropriate enrichment functions. Since the given quantities for influence radii of nodal points could bring about poor quality of interpolation for plates with sharp corners, the radii were increased and the method of Lagrange multiplier was used for the purpose of applying boundary conditions. To demonstrate the capability of the new Hp-Cloud shape functions in the domain of analyzing plates in different geometry shapes, various test cases were correspondingly investigated and the obtained findings were compared with those available in the related literature. Such results concerning these new Hp-Cloud shape functions revealed a significant consistency with those reported by other researchers.

• 대한전자공학회논문지SP
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• 제48권2호
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• pp.96-101
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• 2011

소실점이란 실제 공간의 평행한 선들이 영상 내에 투영되면서 한곳에 모이는 점이다. 본 논문에서는 이러한 소실점의 특성을 이용한 실시간 소실점 검출 알고리즘을 제안한다. 기존의 소실점 검출 방법은 1) 복잡한 계산이 요구되거나 2) 알고리즘에 따라 소실점을 검출할 수 있는 영상이 제한되어 있다. 제안하는 방법은 블록 기반의 HOG(Histogram of Oriented Gradient)를 구하여 영상의 구조적 특성을 이용하는 것으로 영상 내에 존재하는 소실점을 실시간으로 검출한다. 먼저 영상의 블록 단위로 HOG 기술자를 구한 뒤, 제안하는 동적 프로그래밍(dynamic programing)을 이용하여 소실점의 위치를 예측한다. 본 논문에서는 다양한 영상에 대한 실험을 통해 제안하는 알고리즘이 효율적인 소실점 검출 방법임을 보이고자 한다.

• 에너지공학
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• 제12권3호
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• pp.184-189
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• 2003

본 논문은 Indolene-Methanol Plus Higher Alcohols(MPHA)의 연료 특성에 관한 연구로서, 연료의 물성치를 측정하여 조사하였다. 특히 연료의 물성치 중에서 증류특성, 발열량, 인화점, 비중 및 내수성 등을 조사하여 나타내었다. 이때 알콜의 농도는 청정 Indolene의 용적에 따라서 0 에서부터 100%까지 변화하였다. 연료 물성치 측정에서 Indolene-MPHA 혼합물들이 일반적으로 Indolent-Methanol 혼합물과 비교해서 높은 내수성, 유사한 비중과 인화점, 서로 다른 증류특성을 가지고 있음을 알 수 있다. 여기에서 혼합물 물성치 중 상당수는 실제 값과 비교하여 성분들의 중량비를 사용하여 계산하였다.