• 정보학연구
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• 제2권1호
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• pp.191-207
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• 1999

본 연구는 고객만족모형의 선정에 있어 재구매 의사와 예측타당성을 체계적으로 검토하려는 시도이다. 일반적으로 고객만족의 측정을 위해서는 단일항목척도와 복수항목척도를 사용하고 있다. 그러나 고객이 제품특성을 잘 모르는 경우는 이용하는 모형이나 측정방법에 따라 계산된 지수의 신뢰성이나 구매의도와의 상관관계는 높지 않는 경우가 발생한다. 이러한 문제의 해결을 위하여 본 연구에서는 통상적으로 활용되는 고객만족지수의 다양한 측정방법들에 대해 예측타당성을 검토하여 적절한 모형을 찾아내려는 시도이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2923-2928
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• 2007

The study of model for velocity and turbulence within the urban canopy was carried out. To evaluate existing urban model we conducted wind tunnel experiment and large-eddy simulation (LES). Mean velocity profile and turbulence are measured within simple three different obstacle arrays. To obtain supplemental data and to verify morphological model large-eddy simulation was performed. Several methods have been used to achieve embodying the flow field in urban area. Recently, morphological method obtaining flow parameters from the statistical or physical representation of obstacle elements is a arising method. It was found that all morphological model, evaluated in this study, over predict the friction velocity, most sensitive one among the flow parameters. Velocity and turbulence in the urban canopy layer were improved by the correction using 'true' friction velocity.

• 한국해양공학회지
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• 제25권3호
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• pp.19-27
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• 2011

In case of constructing submerged breakwaters for the purpose of preventing coastal erosion, the number of submerged breakwaters, as well as their asymmetry is dependent on the field conditions. The aim of the present study was to examine the 3-D hydrodynamic characteristics (3-D wave field, wave height, mean water level, and mean flow) around the asymmetric submerged breakwaters using a 3-D numerical model, LES-WASS-3D, which was validated through a comparison with existing experimental data and showed fairly nice agreement. From the numerical results, the wave height, mean water level, and mean flow are discussed in relation with the variation in the breakwater length ratio.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.910-914
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• 2001

The teat number of a sow plays an important role for weaning pigs and has been utilized in selection of swine breeding stock. Various linear models have been employed for genetic analyses of teat number although the teat number can be considered as a count trait. Theoretically, Poisson error mixed models are more appropriate for count traits than Normal error mixed models. In this study, the two models were compared by analyzing data simulated with Poisson error. Considering the mean square errors and correlation coefficients between observed and fitted values, the Poisson generalized linear mixed model (PGLMM) fit the data better than the Normal error mixed model. Also these two models were applied to analyzing teat numbers in four breeds of swine (Landrace, Yorkshire, crossbred of Landrace and Yorkshire, crossbred of Landrace, Yorkshire, and Chinese indigenous Min pig) collected in China. However, when analyzed with the field data, the Normal error mixed model, on the contrary, fit better for all the breeds than the PGLMM. The results from both simulated and field data indicate that teat numbers of swine might not have variance equal to mean and thus not have a Poisson distribution.

• 대한기계학회논문집A
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• 제26권3호
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• pp.553-559
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• 2002

Carbon-fiber which has very small radial dimension makes us difficult to measure it's properties. So in this paper, we suggest a simple method to measure the thermal conductivity of a carbon-fiber's and carbon-fiber-reinforced-plastics(CFRP) laminates. The thermal conductivity of CFRP laminates was measured experimentally at the same time analytically. The experimental model is based on the one-dimensional analysis of fin sample because CFRP laminates has a thin geometric configuration. The analytical model to measure the thermal conductivity of carbon-fiber is expressed by use of mean-field model which is based on Eshelby's elliptical inclusion problem. Therefore the thermal conductivity of angle-ply laminates can be computed by use of effective longitudinal and transverse thermal conductivities of unidirectional composite of the constituents.

• 한국농공학회지
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• 제39권4호
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• pp.114-121
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• 1997

In order to provide basic information for the estimation of evapotranspiration in the ponded direct seeding paddy field, both field lysimeter experiment and model prediction were performed to estimate daily ET. Various methods were used to predict daily reference crop ET and crop coefficients. Measure4 mean daily ET during the 1995 growing season varied from 5.9 to 6.1 mm depending on the species, while it varied from 5.1 to 5.5 mm in 1996. Model predicted mean daily ET during the 1995 growing season varied from 3.9 to 4.9 mm depending on the prediction model, while it varied from 3.5 to 4.7 mm in 1996. The smaller ET values both measured and predicted in 1996 were caused by the low values of temperature, sunshine hours, and solar radiation. Crop coefficients varied from 1.20 to 1.50 in 1995 depending on the prediction model, while it varied from 1.10 to 1.47 in 1996. Comparison of the seven reference crop ET prediction methods used in this study shows that the Penman-Monteith method and the FAO-Radiation method gave the lowest ET while the corrected Penman method and the Hargreaves method gave the largest ET. Since crop coefficients vary to a large extent based on the prediction methods, reference crop ET prediction method should be carefully selected in irrigation planning.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.673-678
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• 2005

The objective of this paper is to develop the microorganism concentration simulation model for the health related effect analysis while farmers and water managers reuse the wastewater for agricultural irrigation. This model consists of the CE-QUAL-R1 model and the CREAMS-PADDY model. The CE-QUAL-R1 model is the 1-D numerical model to analyze the water quality of the reservoir and the CREAMS-PADDY model is modified from CREAMS model for considering the hydrologic cycles in paddy field. This model was applied to examine the application by the observed data from 2003 in Byoungjum study area. From this research, the average root mean square error (RMSE) for the simulated concentration during the calibration period was 0.51 MPN/100ml and correlation coefficient $(R^2)$ was 0.71. And the RMSE for the simulated concentration during the verification period was 0.46 MPN/100ml and $R^2$ was 0.73. This simulation results show that the coliform inflow concentrations by the wastewater irrigation wield great influence upon the temporal coliform concentrations in paddy field.

• 컴퓨터교육학회논문지
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• 제9권5호
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• pp.1-11
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• 2006

본 연구는 ARCS 모형을 적용한 전산수업에서 인지유형이 학습동기와 학업성취도에 미치는 영향에 관해 살펴보고자 하는데 목적이 있다. 이를 위해 경기도 수원에 소재한 A 고등학교 학생 70명을 4개 집단(ARCS 모형 적용 수업-장독립, ARCS 모형 적용 수업-장의존, 전통적 수업-장독립, 전통적 수업-장의존)으로 나누어 실험을 실시했다. 본 연구의 결과는 다음과 같다. 첫째, 각 집단 간 사후 학습동기의 평균값은 유의수준 5%에서 통계적으로 유의미한 차이를 보였다. 특히 사후검증 결과, 'ARCS 모형 적용 수업-장독립' 집단(M=3.36)과 '전통적 수업-장독립' 집단(M-3.18) 간에 유익미한 차이가 있었다. 또한 학습동기의 사전-사후검사 향상점수 분석 결과, '전통적 수업 장의존형' 집단을 제외한 모든 집단에서 통계적으로 유의미한 차이를 보였다. 둘째, 각 집단 간 사후 학업성취도의 평균값은 유의수준 5%에서 통계적으로 유의미한 차이가 나타나지 않았다. 또한 사전-사후 학업성취도 검사의 향상점수 분석 결과, ARCS 모형 적용여부와 인지유형에 관계없이 4개 집단 간 학업성취도 평균 간에는 유의미한 차이를 보였다. 이 결과는 향후 맞춤형 교수설계를 통한 개별화된 교수 학습 구현에 중요한 시사점을 제공해 줄 것이다.

• 한국농공학회논문집
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• 제60권5호
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• pp.55-67
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• 2018

The objectives of this study were to monitor organic farming upland compared with conventional upland field and to evaluate nutrient loads reduction of surface cover effect with long-term historical climate data. APEX(Agricultural Policy Environmental eXtender) model was validated with experimental data and used for assessing surface cover scenarios for 30-year simulation periods. The validated values of RMSE(Root Mean Square Error), RMAE(Root Mean Absolute Error), $R^2$ and E(Nash-Sutcliffe efficiency) for runoff were 1.17-1.37 mm/day, 0.28-0.45 mm/day, 0.88-0.90 and 0.82-0.94 in two treatments, respectively. Those for water quality (nitrogen) were 0.05-0.16 kg/ha, 0.52-0.75 kg/ha, 0.67-0.72 and 0.32-0.70 in two treatments, respectively, and therefore the validated model showed good agreement with the observed runoff and nitrogen load for the study period. When decreasing the surface cover rate of organic farming field to 75%, 50%, 25%, and 0% (conventional field), average annual runoff increased by 7%, 15%, 23% and 31%, respectively. Under same condition of decreasing the surface cover rate, average annual nitrogen loads increased by 1.4 times, 1.7 times, 2.0 times, and 2.3 times compared with organic farming field, respectively. This study showed that it is possible to present an appropriate surface cover ratio to maintain conventional production and minimize nonpoint sources pollution for organic farming system, although long-term monitoring is needed to determine its effects on environmental concerns, crop competition, and other uncertainty.

• 천문학회지
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• 제29권spc1호
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• pp.313-314
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• 1996

Assuming that the solar activity and the solar cycle phenomena may be manifestations of global torsional MHD oscillations, we compute the Alfven wave travel times along the field lines in the five models of magnetic field described in the following text. For all these models, we compute standard deviation and it's ratio to mean Alfvenic wave travel times. The last two models yield the smallest relative bandwidth for the frequencies of the MHD oscillations. However, the last model is the only admissible one which can sustain global Alfvenic oscillations with well defined frequency for the fundamental mode