• Communications for Statistical Applications and Methods
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• 제22권4호
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• pp.349-359
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• 2015

We study a semiparametric Bayesian approach to small area estimation under a nested error linear regression model with area level covariate subject to measurement error. Consideration is given to radial basis functions for the regression spline and knots on a grid of equally spaced sample quantiles of covariate with measurement errors in the nested error linear regression model setup. We conduct a hierarchical Bayesian structural measurement error model for small areas and prove the propriety of the joint posterior based on a given hierarchical Bayesian framework since some priors are defined non-informative improper priors that uses Markov Chain Monte Carlo methods to fit it. Our methodology is illustrated using numerical examples to compare possible models based on model adequacy criteria; in addition, analysis is conducted based on real data.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1998년도 춘계학술대회논문집
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• pp.161-166
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• 1998

In this study, the optimum criteria of space between the lines and the letters which could largely affect the legibility were found by the experiment and were presented as guidelines to design Korean VDT screens. Since the experiment was designed to test the human performance based on the VDT screen design, searching speed (S.S) and error rate (E) were used as the criteria of performance, and CFF value was measured to evaluate user's visual fatigue. The EOG value was also measured for the visual restriction during the experiment for the space between the lines and letters.

• 한국해양환경ㆍ에너지학회지
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• 제14권2호
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• pp.107-113
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• 2011

해수유동모델의 검증 및 평가를 위해 적용되는 또는 적용가능한 10종류의 모델 오차평가방법 - 네가지의 정량적 평가방법(절대평균오차, 평균제곱근 오차, 상대적 절대평균오차, 백분율모델오차)과 여섯가지의 정성적 평가방법(상관계수, 신뢰지수, 일치지수, 모델효율성, 비용함수, 잔여량계수) - 을 소개하고, 실제 조위, 유속, 염분관측치와 3차원 곡선형 모델(CH3D)에서 구해진 플로리다 하구에서의 수치해에 이들 모델 오차평가방법들을 적용하였다. 조위 및 유속평가시 절대평균오차, 평균제곱근 오차, 상대적 절대평균오차, 상관계수, 일치지수, 모델효율성, 비용함수, 잔여량계수 등이 적합하였다. 그리고 염분평가시 절대평균오차, 평균제곱근 오차, 상대적 절대평균오차, 백분율모델오차, 상관계수, 신뢰지수, 비용함수, 잔여량계수 등의 사용이 타당하였다. 정량/정성적 평가방법들이 서로 유사한 평가경향을 보여 줌으로써, 상호간의 신뢰성도 보여 주었다. 다양한 모델 오차평가방법을 통하여 계산된 평가값을 토대로, 본 연구에서는 조위, 유속, 염분이 잘 재현된 해수유동모델의 평가범위를 제시하였다. 조위의 경우 상대적 절대평균 오차는 10%이내, 상관계수는 0.95이상, 일치지수는 0.98이상, 모델효율성은 0.93이상, 비용함수는 0.21이내이며, 유속의 경우 상대적 절대평균오차는 20%이내, 상관계수는 0.7이상, 일치지수는 0.8이상, 모델효율성은 0.5이상, 비용 함수는 0.5이내이며, 염분의 경우 상대적 절대평균오차와 백분율모델오차는 10%이내, 상관계수는 0.9이상, 신뢰지수는 1.15이내, 비용함수는 0.1이내 이다.

• 대한전자공학회논문지SD
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• 제41권9호
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• pp.39-48
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• 2004

최근 3세대 이동통신의 오류정정부호의 표준으로 채택된 터보 코드는 샤논의 한계에 가까운 성능을 보이며, 반복적인 디코딩 과정의 특성상 이동통신 시스템에서 전력 소모가 많은 블록 중 하나이다. 따라서 이동통신 기기의 전력 소모를 최소화하기 위한 노력으로 터보 디코더의 전력 소모를 줄이는 방법들에 대한 연구가 진행되어왔다. 본 논문에서는 디코딩 가능 임계값과 불가능 임계값 등 두개의 정지 기준을 적용함으로써 기존의 반복 디코딩 정지 기준 알고리즘을 개선하여, 오류정정 성능과 전력 소모면에서 기존의 방법보다 효율적인 새로운 터보 디코더 기술을 개발하였다. 실험 결과, 제안한 방법은 기존의 대표적인 방법에 비하여, 전체 12500회 실험 중 잘못된 오류정정 횟수는 평균적으로 89% 감소시키고 반복 디코딩 횟수는 29% 감소시킬 수 있었다.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.211-230
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• 2008

Owing to the growing size of the eigenvalue problem and the growing number of eigenvalues desired, solution methods of iterative nature are becoming more popular than ever, which however suffer from low efficiency and lack of proper convergence criteria. In this paper, three efficient iterative eigenvalue algorithms are considered, i.e., subspace iteration method, iterative Ritz vector method and iterative Lanczos method based on the cell sparse fast solver and loop-unrolling. They are examined under the mode error criterion, i.e., the ratio of the out-of-balance nodal forces and the maximum elastic nodal point forces. Averagely speaking, the iterative Ritz vector method is the most efficient one among the three. Based on the mode error convergence criteria, the eigenvalue solvers are shown to be more stable than those based on eigenvalues only. Compared with ANSYS's subspace iteration and block Lanczos approaches, the subspace iteration presented here appears to be more efficient, while the Lanczos approach has roughly equal efficiency. The methods proposed are robust and efficient. Large size tests show that the improvement in terms of CPU time and storage is tremendous. Also reported is an aggressive shifting technique for the subspace iteration method, based on the mode error convergence criteria. A backward technique is introduced when the shift is not located in the right region. The efficiency of such a technique was demonstrated in the numerical tests.

• Journal of the Korean Statistical Society
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• 제8권1호
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• pp.37-64
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• 1979

Criteria and designs are developed for estimating derivatives of P-variable second order polynomial response surfaces. The basic criterion used is mean square error of the estimated derivative, averaged over all directions and then averaged over a region of interest. A new design concept called slope-rotatability is introduced. A simplex optimization program is used to find minimum mena square error designs for the two variable case for $6 \leq N \leq 12$.

• 한국수자원학회논문집
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• 제39권8호
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• pp.677-690
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• 2006

본 연구에서는 LH-OAT (Latin Hypercube Ore factor At a Time) 민감도분석 방법과 SCE-UA (Shuffled Complex Evolution at University of Arizona) 최적화 기법을 적용하여 보청천 유역에서 SWAT모형에 대한 자동보정 방법을 제시하였다. LH-OAT 방법은 전역 민감도분석과 부분 민감도 분석의 장점을 조합하여 가용매개변수 공간에 대하여 효율적으로 매개변수의 민감도 분석이 가능하게 하였다. LH-OAT민감도 분석으로부터 결정된 매개변수의 민감도 등급은 SWAT 모형의 자동보정 과정에서 요구되는 보정대상 매개변수의 선택에 유용하게 적용될 수 있다. SCE-UA 방법을 적용한 SWAT모형의 자동보정 해석결과는 보정자료, 보정매개변수, 통계적 오차의 선택에 따라서 모형의 성능이 좌우되었다. 보정기간과 보정매개변수가 증가함에 따라 검증기간에 대한 RMSE (Root Mean Square Error), NSEF (Nash-Sutcliffe Model Efficiency), RMAE (Relative Mean Absolute Error), NMSE (Normalized Mean Square Error) 등의 모형오차는 감소하였지만, NAE (Normalized Average Error) 및 SDR(Standard Deviation Ratio)은 개선되지 않았다. SWAT모형의 보정에 적용되는 보정자료, 보정매개변수 및 모형평가를 위한 통계적 오차 선택이 해석결과에 미치는 복잡한 영향을 이해하기 위하여 다양한 대표유역을 대상으로 추가적인 연구가 필요하다.

• KIEAE Journal
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• 제13권5호
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• pp.79-88
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• 2013

This study creates the evaluation criteria to analyze the $CO_2$ emission quantity in the complex of apartment house among domestic buildings and proposes how to calculate the $CO_2$ emission quantity by the only simple information of apartment house. The study shows that in order to create the index of carbon emission evaluation criteria, $CO_2$ emission quantity for its input materials in these 27 apartment houses are 445,412g-$CO_2/m^2$ for apartment building, 474,322g-$CO_2/m^2$ for the basement parking lot, 483,523g-$CO_2/m^2$ for welfare facility, 729,957g-$CO_2/m^2$ for sales facility, 743,560g-$CO_2/m^2$ for other facility, 26,782g-$CO_2/m^2$ for public facility, 43,659g-$CO_2/m^2$ for landscape, 1,113g-$CO_2/m^2$ for indoor facility, 11,251g-$CO_2/m^2$ for outdoor facility and 891g-$CO_2/m^2$ for common temporary based on the average $CO_2$ emission by facility. We can also see the analysis data that in case of using the selected factors only, the rate of error is 7.51% comparing with the emission quantity by using simplified LCA method this study suggests for the whole range of apartment houses and the rate of error is average 3.24% using selective and main materials. And this it is evaluated that we can get the result which is similar to the actual $CO_2$ emission quantity with only the simple information about the apartment house.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.421-424
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• 2002

In this paper, we introduce an encoder design technique of multiple symbol trellis coded modulation for noncoherent continuous phase frequency shift keying (MTCM/NCPFSK) on the interleaved Rician fading channel. To find dominant factors which affects the error probability of MTCM/NCPFSK, we derive the pairwise error probability (PEP) of MTCM/NCPFSK and find that the error probability mainly depends on the effective length of error event and the corresponding squared product distance (SPD) for the small value of Rician parameter K. Using this performance criteria, we search for the optimal encoder of MTCM/NCPFSK for the interleaved Rician fading channel. We also compare that encoder with the encoder designed for additive white Gaussian noise channel.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.411-414
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• 2000

Optical Triangulation Probes (OTPs) are widely used for their simple structure. high resolution, and long operating range. However, errors originating from speckle, inclination of the object, source power fluctuation, ambient light, and noise of the detector limit their usability. In this paper, we propose new design criteria for an error-reduced OTP. The light source module for the system consists of an incoherent light source and a multimode optical fiber for eliminating speckle and shaping a Gaussian beam Intensity profile. A diffuse-reflective white copy paper, which is attached to the object, makes the light intensity distribution on the change-coupled device(CCD). Since the peak positions of the intensity distribution are not related to the various error sources, a sub-pixel resolution signal processing algorithm that can detect the peak position makes it possible to construct an error-reduced OTP system