• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.159-165
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• 2008

For deciding the profitability and feasibility of the construction project, the schematic estimation has to not only link the design decision-making but also estimate the cost with reliability. The Object-based schematic estimation system was developed for easily linking with design-making and supports to evaluate the design alternatives in the design development stage but didn't consider the cost estimated by object supplementary and parameter work item. This research presents the Integrated Object-Parameter Schematic Estimation Model in the design development stage that can lead to more accurately estimate the cost through analyzing historical data from the high-storied office buildings. For the development of the proposed model for schematic estimation, after analyzing and classifying the work items from the Bills of Quantities(BOQs) and drawings of historical data, this research proposed the methods of estimating cost in accordance with attributes of each work item using regression analysis. In addition, a case study is performed for the effectiveness as comparing the proposed model with the previous estimating model.

• Journal of the Korean Data and Information Science Society
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• 제26권1호
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• pp.197-207
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• 2015

야구경기에서 타자의 능력을 평가하는 중요 측도에는 타율, 타점, 홈런, 득점, 출루율 등이 있지만 최근에는 타자의 능력을 OPS, ISO, SECA, TA, RC, XR 등과 같은 포괄적인 지표를 사용하여 나타내는 경우가 많다. 이러한 지표들은 흔히 특정 기간 동안 얻은 데이터를 이용하여 계산된 것이기 때문에 기간에 따라 대체로 큰 편차를 보이는 경우가 많으며 특정 모수 (parameter)를 추정하는 것도 아니다. 본 연구에서는 한국프로야구 선수들의 순수한 타격 능력 (hitting ability)을 모수로 간주하여 통계적 방법으로 추정하고자한다. 타격 능력에 추정에는 타수 (at bat)가 반영된 베이지안 방법이 사용될 것이다.

• 한국환경과학회지
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• 제4권5호
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• pp.41-41
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• 1995

In order to discuss the differences among the SMP(Surface Moisture Availability Parameter), by previous researchers on the basis of their own theoretical and empirical background, we assessed the SMP according to the soil types and volumetric soil water contents. The results are as follows. There are differences among all the five SMAPs. There''s a tendency that the larger grain size, the higher value of parameters. And they divided into two groups for their value: one group has parameters with exponential function and the other with cosine and linear function. The maximum difference between the two groups appears when the volumetric soil water contents are 0.07$m^3m^{-3}$ for sand, 0.l1$m^3m^{-3}$ for loam, 0.12 for clay, and 0.13$m^3m^{-3}$ for silt loam. So, these differences must be considered when we estimate the surface evaporation rate. From field data, the paddy field soil around Junam reservoir is classified as a silt has high wetness, 0.56. So, the parameter obtained from the field measurement is much higher than that of Clapp and Hornberger(1978)''s Table. This study treated the SMP for a certain point of time in winter season. But if we measured the soil water contents continuously, we could obtain better time-dependent parameter.

• Quantitative Bio-Science
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• 제37권2호
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• pp.133-141
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• 2018

Graphical lasso is one of the most popular methods to estimate a sparse precision matrix, which is an inverse of a covariance matrix. The objective function of graphical lasso imposes an ${\ell}_1$-penalty on the (vectorized) precision matrix, where a tuning parameter controls the strength of the penalization. The selection of the tuning parameter is practically and theoretically important since the performance of the estimation depends on an appropriate choice of tuning parameter. While information criteria (e.g. AIC, BIC, or extended BIC) have been widely used, they require an asymptotically unbiased estimator to select optimal tuning parameter. Thus, the biasedness of the ${\ell}_1$-regularized estimate in the graphical lasso may lead to a suboptimal tuning. In this paper, we propose a two-staged bias-correction procedure for the graphical lasso, where the first stage runs the usual graphical lasso and the second stage reruns the procedure with an additional constraint that zero estimates at the first stage remain zero. Our simulation and real data example show that the proposed bias correction improved on both edge recovery and estimation error compared to the single-staged graphical lasso.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.684-701
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• 2016

The Gaussian process model (GPM) is a flexible surrogate model that can be used for nonparametric regression for multivariate problems. A unique feature of the GPM is that a prediction variance is automatically provided with the regression function. In this paper, we estimate the safety margin of a nuclear power plant by performing regression on the output of best-estimate simulations of a large-break loss-of-coolant accident with sampling of safety system configuration, sequence timing, technical specifications, and thermal hydraulic parameter uncertainties. The key aspect of our approach is that the GPM regression is only performed on the dominant input variables, the safety injection flow rate and the delay time for AC powered pumps to start representing sequence timing uncertainty, providing a predictive model for the peak clad temperature during a reflood phase. Other uncertainties are interpreted as contributors to the measurement noise of the code output and are implicitly treated in the GPM in the noise variance term, providing local uncertainty bounds for the peak clad temperature. We discuss the applicability of the foregoing method to reduce the use of conservative assumptions in best estimate plus uncertainty (BEPU) and Level 1 probabilistic safety assessment (PSA) success criteria definitions while dealing with a large number of uncertainties.

• 산업경영시스템학회지
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• 제32권3호
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• pp.99-109
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• 2009

Negative binomial yield model for semiconductor manufacturing consists of two parameters which are the average number of defects per die and the clustering parameter. Estimating the clustering parameter is quite complex because the parameter has not clear closed form. In this paper, a Bayesian approach using Markov Chain Monte Carlo is proposed to estimate the clustering parameter. To find an appropriate estimation method for the clustering parameter, two typical estimators, the method of moments estimator and the maximum likelihood estimator, and the proposed Bayesian estimator are compared with respect to the mean absolute deviation between the real yield and the estimated yield. Experimental results show that both the proposed Bayesian estimator and the maximum likelihood estimator have excellent performance and the choice of method depends on the purpose of use.

• 한국구조물진단유지관리공학회 논문집
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• 제22권1호
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• pp.48-55
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• 2018

본 연구의 목적은 구조 시스템의 구조적 손상에 의한 고유주파수 감소율과 감쇠변수 증가율을 비교 분석하는 것이다. 이를 위하여 저주파 영역의 고유주파수와 비교적 높은 감쇠변수 특성을 갖는 2경간 H-Beam을 대상으로 실내실험과 수치해석을 수행하였으며, 충격하중에 대한 손상 전과 손상 후 응답신호를 각각 14개 위치에서 분석하였다. 각 위치에 대한 손상 전과 손상 후 응답신호는 푸리에 변환을 통하여 고유주파수 감소율을 분석하였으며, 감쇠변수 증가율은 웨이블릿 변환을 통하여 수행되었다. 웨이블릿 변환은 최대 웨이블릿 계수에 대응되는 스케일의 시간함수 분리가 가능하기 때문에 감쇠변수 평가에 대한 정확성을 높일 수 있다. 손상 전과 손상 후 계측된 응답신호에 대하여 고유주파수 감소율은 민감하지 못한 결과로 평가되었고, 감쇠변수 증가율은 비교적 큰 변화량을 보여 구조 시스템의 손상도 평가에 신뢰할 수 있는 결과를 보여주었다.

• Journal of applied mathematics & informatics
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• 제29권5_6호
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• pp.1257-1268
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• 2011

The thermal behavior of wood exposed to the outdoors is influenced by solar absorptivity and longwave emissivity. However, it is difficult to measure that properties directly. Hence we estimate the values of the parameter by using the least-square optimization technique. Finally we report the results for the computation of the values of the parameters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.563-565
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• 2005

In this study, a algorithm to estimate Equivalent earth resistivity and Earth parameter using Artificial Neural Network(ANN) was proposed. Structures of the soil are grouped by using SOM algorithm before estimation. Earth parameter and Equivalent earth resistivity are obtained by using BP algorithm. The effectiveness of the proposed algorithm was verified. In the case study. afterwards, the algorithm proposed in this study will be used in more applications and gained more reliability.

• 한국통신학회논문지
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• 제9권4호
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• pp.163-169
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• 1984

本論文에서는 平均値가 確率密度函數의 퍼래미터의 函數일 때 確率1과 mean square로 수렴하는 새로운 母數推定알고리즘을 提案한다. 提案된 逐次알고리즘음 推定하려는 퍼래미터가 다수의 퍼래미터일 경우라도 적용시킬 수 있으며 컴퓨터 시뮬레이션에 의해 결과의 타당성을 입증하였다.