• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2002.11a
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• pp.97-117
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• 2002

A chemoinfometrical method for quantitative determination of crystal content of indomethacin (IMC) polymorphs based on fourie-transformed near-infrared (FT-NIR) spectroscopy was established. A direct comparison of the data with the ones collected from using the conventional powder X-ray diffraction method was performed. Pure $\alpha$ and ${\gamma}$ forms of IMC were prepared using published methods. Powder X-ray diffraction profiles and NIR spectra were recorded for six kinds of standard materials with various content of ${\gamma}$ form IMC. The principal component regression (PCR) analyses were performed based on normalized NIR spectra sets of standard samples of known content of IMC ${\gamma}$ form. A calibration equation was determined to minimize the root mean square error of the prediction. The predicted ${\gamma}$ form content values were reproducible and had a relatively small standard deviation. The values of ${\gamma}$ form content predicted by two methods were in close agreement. The results were indicated that NIR spectroscopy provides for an accurate quantitative analysis of crystallinity in polymorphs compared with the results obtained by conventional powder X-ray diffractometry.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.95.2-95.2
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• 2012

We have compared the geoeffective parameters of halo coronal mass ejections (CMEs) to predict geomagnetic storms. For this we consider 50 front-side full halo CMEs whose asymmetric cone model parameters and earthward direction parameter were available. For each CME we use its projected velocity (Vp), radial velocity (Vr), angle between cone axis and sky plane (${\gamma}$) from the cone model, earthward direction parameter (D), source longitude (L), and magnetic field orientation (M) of the CME source region. We make a simple and multiple linear regression analysis to find out the relationship between CME parameters and Dst index. Major results are as follows. (1) $Vr{\times}{\gamma}$ has a higher correlation coefficient (cc = 0.70) with the Dst index than the others. When we make a multiple regression of Dst and two parameters ($Vr{\times}{\gamma}$, D), the correlation coefficient increases from 0.70 to 0.77. (2) Correlation coefficients between Dst index and $Vr{\times}{\gamma}$ have different values depending on M and L. (3) Super geomagnetic storms (Dst ${\leq}$ -200 nT) only appear in the western and southward events. Our results demonstrate that not only the cone model parameters together with the earthward direction parameter improve the relationship between CME parameters and Dst index but also the source longitude and its magnetic field orientation play a significant role in predicting geomagnetic storms.

• Health Policy and Management
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• v.27 no.1
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• pp.47-55
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• 2017

Background: This study purposed to analyze the effects of metabolic syndrome on the total medical charge of patients. Methods: 2013 National Health Insurance Service sample research database (eligibility database, medical database, and health examination database) was used for this study. Gamma regression was applied to analyze the effects of metabolic syndrome on the total medical charge and logistic regression was used to determine the probability of medical charge which was higher than the third quartile. Sociodemographic characteristics (age and household income), health behavior factors (smoking, drinking, exercise, and body mass index), and disease related factors (family history and metabolic syndrome) were included as the independent variables. Results: people who had metabolic syndrome spent more medical expenses than those without metabolic syndrome both in man and woman group. The standard regression coefficient was 0.09 (p< 0.001) in man with metabolic syndrome and 0.16 (p< 0.001) in woman. In addition, woman with metabolic syndrome spent more than the third quartile of medical charge. The odds ratios was 1.04 (p= 0.16) for man with metabolic syndrome and 1.18 (p= 0.013) for woman. Conclusion: people with metabolic syndrome spent more medical charge, so it will need to consider policy interventions for preventing the incidence and management of metabolic syndrome in Korean people.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.502-504
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• 1996

Plate(후판) design은 수요가 주문시 지정size(두께, 폭)로 부터 당사 압연 process를 거치면서 발생하는 지시대비 실적간의 차이를 보정하여 최종적으로 산출하게 되며, 이러한 과정은 제품생산시 size 부족으로 인한 불량 발생을 방지하는데 그 목적이 있다. Process진행중 size실적은 .gamma.-ray등 각종 측정기기로 부터 자동 측정되며 이는 process computer로 부터 main computer로 일별 전송되어 3개월 동안 조업관리 DATA BASE에 누적관리되고 있다. 본 연구는 이러한 조업실적을 근거로 제조과정에서 발생하는 size오차를 probability theory과 MULTI-REGRESSION 기법을 적용하여 DESIGN LOGIC을 개발, 제품 실수율을 향상하는데 그 목적이 있다.

• Journal of the Korean Data and Information Science Society
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• v.10 no.1
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• pp.193-198
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• 1999

The estimation of parameters in regression models with multiplicative errors is usually based on the gamma or log-normal likelihoods. Under reciprocal misspecification, we compare the small sample efficiencies of two sets of estimators via a Monte Carlo study. We further consider the case where the errors are a random sample from a Weibull distribution. We compute the asymptotic relative efficiency of quasi-likelihood estimators on the original scale to least squares estimators on the log-transformed scale and perform a Monte Carlo study to compare the small sample performances of quasi-likelihood and least squares estimators.

• The Korean Journal of Applied Statistics
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• v.31 no.4
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• pp.475-484
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• 2018

Gamma generalized linear models are useful for non-negative and skewed responses. However, these models have received less attention than Poisson and binomial generalized linear models. In particular, hypothesis testing for the significance of regression coefficients has not been thoroughly studied. In this paper we assess the performance of various test statistics for gamma generalized linear models based on numerical studies. Our results show that the likelihood ratio test and F-type test are generally recommended and that the partial deviance test should be avoided in practice.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.4
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• pp.110-124
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• 1996

This study was conducted to simulate long seres of synthetic monthly flows by multi-season first order Markov model with selection of best fitting frequency distribution, harmonic synthetic and harmonic regression models and to make a comparison of statistical parameters between observes and synthetic flows of five watersheds in Geum river system. The results obtained through this study can be summarized as follow. 1. Both gamma and two parameter lognormal distributions were found to be suitable ones for monthly flows in all watersheds by Kolmogorov-Smirnov test. 2. It was found that arithmetic mean values of synthetic monthly flows simulated by multi-season first order Markov model with gamma distribution are much closer to the results of the observed data in comparison with those of the other models in the applied watersheds. 3. The coefficients of variation, index of fluctuation for monthly flows simulated by multi-season first order Markov model with gamma distribution are appeared closer to those of the observed data in comparison with those of the other models in Geum river system. 4. Synthetic monthly flows were simulated over 100 years by multi-season first order Markov model with gamma distribution which is acknowledged as a suitable simulation modal in this study.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.55-64
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• 2004

Maximum dry unit weight, ${\gamma}_{dmax}$, is the most important engineering properties for subgrade soil. Existing models to predict ${\gamma}_{dmax}$ containing many parameters, seem to be rather complex. This paper presents new simple models to predict ${\gamma}_{dmax}$. for sandy soils, A number of sieve analysis and compaction tests for 36 types of sands were conducted to develop the regression-based models. Parameters used to estimate ${\gamma}_{dmax}$ are both the geometric mean and geometric standard deviation of the soils, or the particle-size distribution curve parameters. Maximum dry unit weights predicted by the models are in good agreement with the laboratory measurements for the soil samples obtained at 16 locations within the Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.277-286
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• 2017

This study assesses the association of nurses' hope, grateful disposition, and workplace spirituality with the goals of providing human resource management plans that lead to efficient and competitive nurse structure by building a nurse organizational culture based on analyzing the influences affecting organizational citizenship behavior. Participants were 147 nurses working in four general hospitals in Seoul and Gyeonggi-do. The survey data were analyzed by frequencies, t-test, ANOVA, Pearson correlation coefficients and multiple stepwise regression via SPSS WIN 18.0. Results showed that organizational citizenship behavior is positively associated with nurse's hope (${\gamma}=.22{\sim}.36$, p<.001), grateful disposition (${\gamma}=.38$, p<.001) and workplace spirituality (${\gamma}=.38{\sim}.54$, p<.001). The significant predictors of organizational citizenship behavior were workplace spirituality (${\beta}=.54$, p<.001), hope of turnover (${\beta}=.12$, p<.001), hope (${\beta}=.09$, p<.001) and grateful disposition (${\beta}=.08$, p<.001), which explained 41.6% of the variance in organizational citizenship behavior. This study systematizes a theory for workplace spirituality processing the early stage research in nurse structure. To improve organizational citizenship behavior among nurses, educational programs and supporting systems should be developed to increase nurses' hope, disposition of grateful disposition, and workplace spirituality.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.3
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• pp.238-244
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• 2017

Objectives: The major objective of this study was to investigate the prevalence of and risk factors for latent tuberculosis infection (LTBI) among employees at a workers' compensation hospital. Methods: Among the 394 employees at Incheon Hospital, 362 were enrolled in the study. An interferon-gamma release assay(IGRA) for diagnosis of LTBI was performed using QuantiFERON$^{(R)}$ TB Gold In-Tube(QFT-IT). Risk factors for LTBI were analyzed using logistic regression analysis. Results: The overall prevalence of LTBI was 32.0%(116/362). The non-medical departments have a significantly high prevalence compared to medical departments(39.7% vs 23.2%). In multivariate logistic regression analysis, experience working in the pneumoconiosis hospital(OR, 3.6; 95% CI, 1.3-10.3) was associated with development of LTBI. Conclusions: Korean guidelines for the management of tuberculosis recommend annual regular health examinations for TB and LTBI for health care workers(HCWs). Considering the high prevalence of and risk factors for LTBI among non-HCWs, it suggests a need for annual regular health examinations for TB and LTBI for all employees at workers' compensation hospitals, including pneumoconiosis hospitals.