• 한국생산제조학회지
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• 제22권3호
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• pp.394-401
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• 2013

A new Rockwell hardness (HRC) model using a volumetric parameter by a least square and fractal interpolation method is suggested. The results are also investigated in comparison to real measured hardness data. For this purpose, the measurement of an indented volume is performed using a confocal laser scanning microscope (CLSM), and the captured height encoded image (HEI) is used as an original surface for the calculation of the indented volume. After configuring the surface, the constructed volume is calculated and used as an independent variable for HRC hardness modeling. The hardness model is established using an experimental modeling technique involving a least square algorithm and fractal interpolating model, and this suggested model can be used to reliably predict the Rockwell hardness. These techniques can also be applied to the modeling of the Brinnell and Vickers hardnesses using a volumetric variable.

• 전기학회논문지
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• 제60권1호
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• pp.32-35
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• 2011

The economic value of a wind farm project is influenced by various risk factors such as wind power output and electricity market price. In particular, there is uncertainty in the economic evaluation of a wind farm project due to uncertain wind power outputs, which are fluctuated by weather factors such as wind speed, and volatile electricity market prices. This paper presents a systematic method to assess the economic value and payback period of a wind farm project using Least Square Monte-Carlo (LSMC) simulation. Numerical example is presented to validate the effectiveness of the proposed economic assessment method for a wind farm project.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1379-1382
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• 1997

We introduce a fast implementation of the adaptive transversal filter which uses least-mean-square(LMS) algorithm. The fast Hadamard transform(FHT) is used for the implementation of the filter. By using the proposed filter we can get the significant time reduction in computatioin over the conventional time domain LMS filter at the cost of a little performance. By computer simulation, we show the comparison of the propsed Hadamard-domain filter and the time domain filter in the view of multiplication time, mean-square error and robustness for noise.

• 한국산업보건학회지
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• 제17권1호
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• pp.21-30
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• 2007

To establish the Fourier-transform infra-red spectrophotometry (FTIR) direct-on-filter(DOF) technique as a useful analytical method for quartz in respirable dust samples, influence of the interference should be corrected. This study was designed to compare three methods of correction for cristobalite when quantifying the content of quartz, including the least square, the optimum choice and the spectral subtraction methods. Respirable dust, created in a dust chamber containing the standard material of quartz, cristobalite was collected using a cyclone equipped with a 25 mm, $0.8{\mu}m$ pore size DM filter as a collection medium. The quartz weights overestimated about 100% when mixed of cristobalite by measure using 799 cm-1 absorption peak of quartz. The quartz weights appeared over estimated by optimum choice, spectral subtraction and least square method in mixtures of 33% cristobalite were 90.3%, 60.1% and about 4.3%, respectively. The least square method have been adopted to correction methods of cristobalite and satisfactory results have been obtained. The results of this study suggest that, when correcting for effect of cristobalite on quantitative analysis of quartz in respirable dust by FTIR direct-on-filter method, the least square method produce the most unbiased results compared with those of other correction methods.

• 한국통신학회논문지
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• 제29권10C호
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• pp.1425-1432
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• 2004

기존의 LSE(Least Square Estimation)를 이용한 영상보간 방법은 다른 방법들 보다 고주파 성분인 에지 부분의 보간 성능이 뛰어나고 월등한 주관적 화질의 향상을 보인다. 하지만 같은 고주파 성분인 잡음 성분의 증폭으로 인해 보간 된 일부 영상은 자연스럽지 못하는 문제점이 있다. 또한 연산량과 메모리 요구량이 상당히 높아 실시간이나 고속 구현에 어려움이 따른다. 본 논문에서 제안하는 방법은 단순한 샘플윈도우와 Direction Detector를 사용하여 보간 연산에 사용되는 참조 화소의 개수를 화질의 열화 없이 줄임으로써 연산량과 메모리 요구량을 획기적으로 줄였다. 또한 Bi-Linear 보간 방법을 선택적으로 적용함으로써 기존 방법에서 에러가 생기는 부분을 보완하였다. 컴퓨터 모의 실험 결과 기존의 LSE를 이용한 보간 방법 보다 주관적인 화질이나 객관적인 화질에서도 보다 나은 결과를 보여 주는 것을 확인하였다.

• 한국강구조학회 논문집
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• 제17권6호통권79호
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• pp.727-736
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• 2005

본 연구에서는 사장교의 적절한 초기평형상태 결정을 위하여 최소자승법을 이용한 케이블 장력 결정 방법을 제시하였다. 본 방법은 거더의 케이블 지지점을 지점으로 한 연속보로부터의 처짐 및 모멘트 등을 목표치로 하고 케이블을 포함한 사장교 전체계 해석으로부터 구해진 응답과의 차이를 오차로 정의하여 거더 및 주탑의 오차를 최소화하는 방법이다. 특히, 주탑 모멘트, 거더 모멘트, 그리고 처짐의 보정 정도를 가중행렬을 도입하여 선택적으로 조절할 수 있으며, 여러 가지 사장교 형식에 대한 수치예제 및 기존 연구와의 비교를 통하여 본 방법의 효율성 및 타당성을 검증하였다.

• 한국산업보건학회지
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• 제19권1호
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• pp.1-7
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• 2009

To establish the Fourier-Transform Infra-Red spectrophotometry(FTIR) Direct-On-Filter(DOF) technique as a useful analytical method for quartz in respirable dust samples, an influence of the kaolinite should be corrected. Respirable dust, created in a dust chamber containing the standard material of quartz and kaolinite were collected using a cyclone equipped with a 25 mm, $0.8\;{\mu}m$ pore size DM filter as a collection medium. This study was designed to compare three methods of correction for kaolinite when quantifying the content of quartz, including the least square, the optimum choice and the spectral subtraction methods. The content of quartz in the respirable dust samples was overestimated by 6.2% when mixed with kaolinite(35.5% by weight). The content of quartz containing kaolinite(72.8% by weight) were overestimated by 32%. The spectral subtraction method underestimated the quartz content by 1.5%, while the other two correction methods, the optimum choice and the least square method, overestimated the quartz content by 1.9% to 6.4% and 0.04 to 1.1%, respectively. The results of this study are suggested that, when correcting for effects of kaolinite on quantitative analysis of quartz in respirable dust by FTIR direct-on-filter method, the least square method produce the most unbiased results be compared with those of other correction methods.

• ETRI Journal
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• 제33권5호
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• pp.806-809
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• 2011

This letter considers the channel estimation for two-way relay MIMO OFDM systems. A least square (LS) channel estimation algorithm under block-based training is proposed. The mean square error (MSE) of the LS channel estimate is computed, and the optimal training sequences with respect to this MSE are derived. Some numerical examples are presented to evaluate the performance of the proposed channel estimation method.

• 한국전산유체공학회지
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• 제13권1호
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• pp.49-56
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• 2008

Chimera grid methods have been widely used in Computational Fluid Dynamics due to its simplicity in constructing grid systems over complex bodies, and suitability for unsteady flow computations with bodies in relative motion. However, the interpolation procedure for ensuring the continuity of the solution over overlapped regions fails when the so-called orphan cells are present. We have adopted the MLS(Moving Least Squares) method to replace commonly used linear interpolations in order to alleviate the difficulty associated with the orphan cells. MLS is one of the interpolation methods used in mesh-less methods. A number of examples with MLS are presented to show the validity and the accuracy of the method.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.349-353
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• 2010

지적측량은 지난 100여 년간 국민의 재산권보호를 위한 사명을 수행하여 왔다. 1999년부터 시작된 도면전산화 업무가 2003년도에 종료되면서 디지털(수치화) 도면을 사용할 수 있는 기반이 마련되었으며, 현재는 컴퓨터로 지적측량을 수행하여 보다 정확한 성과를 제시하고 있다. 통계학뿐 아니라 측량계산 분야에 있어서 최소제곱법만큼 유용하고 넓게 이용되고 있는 원리는 없다. 지적측량의 성과를 보다 정확히 향상시키기 위해서는 관측된 데이터의 처리가 중요함은 두말할 나위가 없다. GPS 측량의 경우는 그 계산방법에 최소제곱법이 도입되어 활용되고 있지만 도근측량과 세부측량의 계산방법은 아직도 100여 년 전의 방법을 그대로 사용하고 있어 오차의 적절한 처리가 이루어진다고 할 수 없다. 따라서 본 연구에서는 GPS이외에 각과 거리 등 원시 데이터를 이용하여 최소 제곱법을 적용 지적측량에 응용할 수 있는 방법을 제시하고자 한다.