• 한국산학기술학회논문지
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• 제20권12호
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• pp.663-670
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• 2019

터빈 사이클 보정 열 성능 분석은 발전소의 현재 성능을 결정하고 향상된 경제성 운전을 위해 요구된다. 본 연구에서는 신뢰성있는 성능 분석을 위해서 산업 표준인 ASME(American Society of Mechanical Engineers) PTC(Performance Test Code)를 기본으로 성능 분석에서 우선적으로 중요하게 적용되는 주급수 유량을 대상으로 영역별 판정 알고리즘을 개발하고 각 영역별로 현재의 터빈 사이클 성능을 추정하는 알고리즘을 개발하였다. 추정 알고리즘은 측정 상태량의 상관 관계를 기반으로 영역별로 형상 분류를 제시하고, 이를 기반으로 커널 회귀 모델을 이용하여 학습된 추정 모델을 구성하였으며, 커널 회귀 모델링의 우수성을 검증하기 위하여 신경 회로망 모델의 학습 결과와 비교하였다. 주급수 유량의 형상 특성에 따른 분류 및 추정 모델은 터빈 사이클에서 정확한 보정 열 성능 분석을 제공함으로써 성능 분석의 신뢰도를 증가시킬 수 있었으며 다른 성능 결정 변수에 대한 학습 및 검증 모델로 사용될 수 있다.

• 한국식품과학회지
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• 제31권3호
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• pp.778-787
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• 1999

시금장의 품질표준화를 위하여 시금장의 제조방법을 조사하고, 시금장의 각종 맛성분과 관능검사 점수사이의 관계를 통계적으로 분석하여 시금장의 맛에 영향을 미치는 성분을 밝히고자 하였다. 시금장의 제조방법은 훈연과정을 거치는 것이 매우 특징적이었다. 시금장의 맛성분 중 아미노산의 함량은 proline>valine>glutamic acid>alanine의 순으로 높았다. 유기산은 acetic acid와 propionic acid만이 검출되었다. 유리당은 glucose>maltose>fructose>inositol>mannitol의 순으로 많은 함량을 보였다. 각 성분의 함량과 관능검사 점수 사이의 단일상관은 전체적으로 낮아 시금장의 맛을 한개의 성분만으로 설명할 수 없었다. 가장 상관이 높은 성분은 inositol과 fructose였다. 단계적 중회귀분석을 행한 결과 절대치와 상대치의 대수변환에서 각각 17와 16개의 성분으로 시금장 맛의 90%를 설명할 수 있었다.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.853-864
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• 2002

In the analysis of categorical data subject to misclassification errors, the observed cell proportions are adjusted by a misclassification probabilities and estimates of variances are adjusted accordingly. In this case, it is important to determine the extent to which misclassification probabilities are homogeneous within a population. This paper considers methods to evaluate the power of chi-squared tests for homogeneity with complex survey data subject to misclassification errors. Two cases are considered: adjustment with homogeneous misclassification probabilities; adjustment with heterogeneous misclassification probabilities. To estimate misclassification probabilities, logistic regression method is considered.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.412-418
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• 2000

The purpose of this study is estimation of daily runoff in the watershed with insufficient hydrological data using tank model. In order to estimate, twentysix watersheds were selected to calibrate tank model parameters that were defined by a trial and error method. Results were correlated with characteristics of watershed. Relationships between the parameters and the watershed characteristics were derived by a multiple regression analysis. The simulation results were in agreement with the observed data.

• 품질경영학회지
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• 제25권2호
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• pp.47-59
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• 1997

In this paper we develop computational algorithms to calculate M-estimators of regression parameters from right-censored data that are naturally collected in quality control. In the case of M-estimators, a new statistical method is also introduced to incorporate concomitant scale estimation in the presence of right censoring on the observed responses. Furthermore, we illustrate this by simulations.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.207-211
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• 2008

국내 건설산업은 급격한 시장변화와 경쟁심화의 과정을 겪으면서 프로젝트 초기 단계의 예산 집행 및 관리의 중요성이 증가하고 있다. 설계 완료 이후의 단계에서 조정 가능한 비용은 20%에 불과하기 때문에, 프로젝트 초기 단계에서 중요한 의사결정이 이루어진다. 하지만 초기 단계에서의 의사결정은 설계정보가 확정되지 않고, 정보가 한정되는 등 불확실성 하에서 이루어진다. 이에 따라, 본 연구는 프로젝트 초기 단계의 정확한 비용 예측을 목적으로 parametric method를 사용하여 공사비 예측 방법을 제안하였다. Parametric method를 이용한 공사비 예측 방법은 프로젝트 초기단계에 사용하기에 적합하며, 특히 신속하게 공사비 예측을 할 수 있다는 장점을 지닌다. 국내 아파트 9개 단지 $11{\sim}15$층 규모의 총 84개동 공공아파트 실적자료를 분석하여 공사비와 영향요인간 상관관계 분석을 실시하였다. 다중공선성 문제를 야기하는 변수를 제거한 후, 다중회귀분석을 통하여 공사비 예측 관계식을 도출하였다.

• 한국IT서비스학회지
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• 제18권4호
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• pp.67-82
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• 2019

The purpose of this study is to improve the calculation method of the software operation pricing proposed by the software business price calculation guide from 'input manpower method' to 'rate calculation method'. The software operation pricing of the input manpower method is not objectively calculated in the domestic IT outsourcing situation where the statistical data based on the activity based estimating is insufficient and it is decided by agreement between the owner and the client. In addition, there was no standard for adjusting the productivity according to the characteristics of the operation service. In order to improve this, an operational correction factor item that can affect the software operation productivity was selected based on foreign and domestic standards, and it was confirmed through the first questionnaire to IT operation managers. In order to determine the level of difficulty of the fixed operational correction factors, the operational correction factor using AHP technique was confirmed through a second questionnaire for pairwise comparison. The operational difficulty calculation table was developed with reference to COCOMO and ITIL standards. Finally, we propose a new pricing scheme that reflects the operating rate. Regression analysis was carried out by collecting the data of the domestic public institutions on the estimated cost and the actual cost calculated from the new rate method software operation pricing. The results of the regression analysis show that the estimated cost and the actual cost are related to each other. Mean magnitude of relative error(MMRE) and PRED[25] analysis were added for accuracy analysis. MMRE and PRED also showed satisfactory results, confirming the possibility of replacing the rate method software operation pricing.

• 한국자동차공학회논문집
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• 제12권2호
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• pp.117-122
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• 2004

The fatigue life in wheels was predicted by simulating the experimental method using Finite-Element analysis. Based on a high frequency fatigue property, calculations of the stresses in wheels were performed by simulating the rotating bending fatigue test. Wheels made of an aluminum alloy(A356.2) were tested using a bending fatigue tester. Results from bending fatigue test showed a linear correlation between bending moment and stress amplitude. Consequently, Finite-Element calculations were performed by a linear analysis. In order to find stress-cycles curves, spoke parts of wheel were tested using a rotary bending fatigue tester. Also, highly accurate Finite-Element analysis requires regression lines and confidence intervals from these results. In conclusion, if the fatigue data related to the material and manufacturing procedure are reliable, the prediction on fatigue lift in wheels can be carried out with high accuracy.

• 한국해양공학회지
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• 제23권3호
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• pp.14-19
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• 2009

The present study developed a model to estimate the light weight of an ultra-large container ship. The weight estimation model utilized container ship data obtained from shipyards and the subdivided this weight data into appropriate weight groups. Parameters potentially affecting the group weight were selected and expanded based on experience for weight estimation, and a correlation analysis was performed by the SPSS program to determine the key parameters characterizing the group weight. A weight estimation model applying the multi-regression analysis was proposed to assess the weight of an ultra-large container ship at the preliminary design stage, and the results obtained by the suggested method showed good agreement with the shipyard data.

• 한국의류학회지
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• 제24권6호
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• pp.928-939
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• 2000

This thesis will study the determinants of consumer satisfaction based on the disconfirmation theory. The proposed questions are first, to find out if desire and expectation are conceptually distinct. Second, to study the effects of desire, expectation, perceived performance, desire congruency, and expectation congruency on clothing satisfaction. The data used in this thesis were obtained from a two stage longitudinal survey. SPSS WIN 8.0 was used for the analysis and the following method such as mean, correlation, t-test, hierarchical regression were applied. The results indicate that first, according to the correlation analysis and crosstab analysis, satisfaction and desire were perceived as two different concepts. Second, using the hierarchical regression analysis to compare the effects of determinants of consumer satisfaction, the model of desire, expectation, performance, desires congruency, expectations congruency best explain the clothing satisfaction. Among them, effects of performance had the strongest impact. Expectation did not influence satisfaction but desire did.