• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.627-641
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• 2012

We consider a model estimation and model selection methods for the multi-way contingency table data with non-response or missing values. We also consider hierarchical Bayesian model in order to handle a boundary solution problem that can happen in the maximum likelihood estimation under non-ignorable non-response model and we deal with a model selection method to find the best model for the data. We utilized Bayes factors to handle model selection problem under Bayesian approach. We applied proposed method to the pre-election survey for the 2004 Korean National Assembly race. As a result, we got the non-ignorable non-response model was favored and the variable of voting intention was most suitable.

• Nutrition Research and Practice
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• v.15 no.6
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• pp.789-797
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• 2021

BACKGROUD/OBJECTIVES: Registered dietitian nutritionists (RDN) are providers of medical nutrition therapy (MNT) to address health and chronic disease. Traditionally, RDNs have provided care in healthcare facilities including hospitals and private care facilities. The purpose of this study was to determine how RDN individualized MNT in the home impacted nutrition, physical activity, and food security. SUBJECTS/METHODS: This is a secondary data analysis. The mean age of the participants (n = 1,007) was 51.6 years old with a mean body mass index (BMI) of 34.1 kg/m². Individualized MNT visits were delivered by an RDN in the home setting from January to December 2019. Participants were referred by healthcare professionals or self-referred. Participants had MNT benefits covered by their health insurance plan (43.3% Medicaid; 39.8% private insurance; 7.9% Medicare, 9% other). Health outcomes related to nutrition care were measured. Outcomes included self-reported consumption of nutrition factors and physical activity. Our secondary outcome focused on food security. The changes in weight, BMI, physical activity, and nutrition factors were analyzed by a linear regression model or linear mixed model, adjusting for age, sex, baseline value, and number of appointments. Food security was summarized in a 2 by 2 contingency table. RESULTS: Baseline values had significantly negative impacts for all changes and number of appointments was significant in the changes for weight and BMI. Increases in physical activity were significant for both female and male participants, 10.4 and 12.6 minutes per day, respectively, while the changes in weight and BMI were not. Regarding dietary factors, the consumption total servings per day of vegetables (0.13) and water (3.35) significantly increased, while the consumption of total servings of whole grain (-0.27), fruit (-0.32), dairy (-0.80) and fish (-0.81) significantly decreased. About 24% (of overall population) and 45% (of Medicaid population) reported improvements in food security. CONCLUSIONS: This study found that home visits were a useful setting for MNT delivered by RDNs. There is a strong need for individualized counseling to meet the participants' needs and personal goals.

• Atmosphere
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• v.28 no.4
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• pp.509-520
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• 2018

The performance of the newly designed Pusan National University Coupled General Circulation Model (PNU CGCM) Ensemble Forecast System which produce 40 ensemble members for 12-month lead prediction is evaluated and analyzed in terms of boreal winter temperature over South Korea (S. Korea). The influence of ensemble size on prediction skill is examined with 40 ensemble members and the result shows that spreads of predictability are larger when the size of ensemble member is smaller. Moreover, it is suggested that more than 20 ensemble members are required for better prediction of statistically significant inter-annual variability of wintertime temperature over S. Korea. As for the ensemble average (ENS), it shows superior forecast skill compared to each ensemble member and has significant temporal correlation with Automated Surface Observing System (ASOS) temperature at 99% confidence level. In addition to forecast skill for inter-annual variability of wintertime temperature over S. Korea, winter climatology around East Asia and synoptic characteristics of warm (above normal) and cold (below normal) winters are reasonably captured by PNU CGCM. For the categorical forecast with $3{\times}3$ contingency table, the deterministic forecast generally shows better performance than probabilistic forecast except for warm winter (hit rate of probabilistic forecast: 71%). It is also found that, in case of concentrated distribution of 40 ensemble members to one category out of the three, the probabilistic forecast tends to have relatively high predictability. Meanwhile, in the case when the ensemble members distribute evenly throughout the categories, the predictability becomes lower in the probabilistic forecast.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.320-331
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• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• Journal of Astronomy and Space Sciences
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• v.26 no.3
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• pp.305-316
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• 2009

In this study, we suggest an empirical forecast of CIR (Corotating Interaction Regions) and geomagnetic storm based on the information of coronal holes (CH). For this we used CH data obtained from He I $10830{\AA}$ maps at National Solar Observatory-Kitt Peak from January 1996 to November 2003 and the CIR and storm data that Choi et al. (2009) identified. Considering the relationship among coronal holes, CIRs, and geomagnetic storms (Choi et al. 2009), we propose the criteria for geoeffective coronal holes; the center of CH is located between $N40^{\circ}$ and $S40^{\circ}$ and between $E40^{\circ}$ and $W20^{\circ}$, and its area in percentage of solar hemispheric area is larger than the following areas: (1) case 1: 0.36%, (2) case 2: 0.66%, (3) case 3: 0.36% for 1996-2000, and 0.66% for 2001-2003. Then we present contingency tables between prediction and observation for three cases and their dependence on solar cycle phase. From the contingency tables, we determined several statistical parameters for forecast evaluation such as PODy (the probability of detection yes), FAR (the false alarm ratio), Bias (the ratio of "yes" predictions to "yes" observations) and CSI (critical success index). Considering the importance of PODy and CSI, we found that the best criterion is case 3; CH-CIR: PODy=0.77, FAR=0.66, Bias=2.28, CSI=0.30. CH-storm: PODy=0.81, FAR=0.84, Bias=5.00, CSI=0.16. It is also found that the parameters after the solar maximum are much better than those before the solar maximum. Our results show that the forecasting of CIR based on coronal hole information is meaningful but the forecast of goemagnetic storm is challenging.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.379-386
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• 2016

Purpose: The present study aims at researching the subjective satisfaction of patients who have experienced both conventional impression taking and digital impression taking to measure the possibility of wide clinical application of digital impression. Materials and methods: The study surveyed 170 adult patients over the age of 20, between October 2015 and April 2016, who voluntarily consented to participation and who experienced both conventional impression and digital impression at five dental hospitals that use intraoral digital impression. A total of 128 surveys were used for data analysis, involving frequency analysis, multiple response frequency analysis, descriptive statistics, and contingency table analysis, with the significance level set at 0.05. Results: Responses on the reason for taking impressions using the digital method appeared in the order of 'for implant treatment' (43.8%), 'for crown treatment' (30.5%), and 'for inlay treatment' (15.6%). Patients satisfaction was higher for digital impression taking than conventional impression taking (P<.05). As the preferred choice of impression, digital impression (60.2%) was higher than conventional impression (11.7%). Responses on the reason for choosing digital impression taking appeared in the order of 'no vomiting reflex' (35.1%), 'reliability of 3D digital scanning' (33.8%), and 'short time' (33.8%). Conclusion: The patients preferred digital impression taking to conventional impression taking in terms of satisfaction.

• Journal of Distribution Science
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• v.14 no.7
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• pp.83-90
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• 2016

Purpose - This study focuses on new type distribution channel that named as Omnichannel. Omnichannel is developed from Multichannel which is used in many distribution channels to buy or selling goods. Omnichannel basically needs an Information and Communications Technologies(ICT) to use, so researcher conduct a Technology Acceptance Model(TAM) to research model. Customer-brand relationship was used as dependent variable to focus on the role of Omnichannel. Research design, data, and methodology - The subject of this study is customer who purchase goods or service through omnichannel. Based on the literature from the preceding research analysis of TAM and customer-brand relationship, this study was constructed by the reference to previous studies, final research model design for figure out casual relationship among perceived ease of use, perceived usefulness, omnichannel use and customer-brand relationship. From 2016 February 3 to March 17, questionnaire survey targeted customers who use online and offline channels. 273 questionnaire survey had conducted, then, 252 survey data were available for empirical analysis. Researcher provide descriptive statistics for checking generality. Cronbach's alpha value was used to check the reliability of data. Exploratory factor analysis was used for purification of values and eigenvalue checking. After EFA, Confirmatory factor analysis was used to prepare structural equation modeling with executing structural equation modeling for confirming hypothesis which developed by researcher. Results - The main results of this empirical study are as follows. First, omnichannel's perceived ease of use has positive significant effect on perceived usefulness(estimate: 0.579). Moreover, omnichannel's perceived ease of use and perceived usefulness has positive significant effect on omnichannel use(estimate: 0.325,0.648). Second, using omnichannel has positive significant effect on brand-customer relationship(estimate: 0.521). Every hypothesis adopted as researcher designed. This study found out the intermediate relationship between perceived ease of use and omnichannel use by investigating hypothesis. Conclusions - Base on the empirical result, this study confirmed that TAM theory perceived has relation with omnichannel. First, factors of TAM has positive effect on omnichannel use, so it highlights the important role of customer based interface and usefulness. Especially, perceived usefulness has high indirect influence on ease of use and use of omnichannel. It seems that when customers try to decide use or not use omnichannel, customers focus on percept benefits from omnichannel. Thus, a provider should applicate attractive price table, accurate product or service information and high switching cost strategy to emphasize the usefulness of omnichannel. Second, using omnichannel enhances the relationship between customers and brand, because there are more time and frequency to serve customers. It is important because good relationship between customers can increase the future's financial performance through word of mouse, positive brand image and loyalty to brand or company. Finally, despite of empirical result and implications, this study has limitations. First, there are only a few previous studies about omnicahnnel, so literature reviews are restricted. While set up the factors which can affect the use of omnichannel, next study should be considered with broader theories or models(ex: contingency theory). Second, omnichannel has developed from multichannel, so comparative analysis is needed between these methods because there is a possibility about different forte character of each distribution system on customer's consuming patterns.

• School Mathematics
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• v.11 no.3
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• pp.389-413
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• 2009

This thesis assumes that the teaching objective of the Probability unit of the 8th grade textbook under the 7th National Curriculum is to enhance the ability to analyze and utilize informations. And we examine them if this point of view is fully reflected. Based on the analysis of the textbook analysis, followings are found. 1) It is necessary to emphasize more enumerating all possible cases and to induce formulae counting the number of possible cases through organizing them 2) The probability is to be decribed more clearly as a likelihood of events and to be introduced and followed through various students' experiences and the relative frequencies. Less emphasis on probability computations, while more emphasis on probability comparisons of events are recommended. 3) The term "influential events"(a kind of stochastic correlation) is ambiguous. It is necessary to make clear what it means at tile level of the 8th grade or to discard it for it is to be learned at the 10th grade again. Especially, contingency table has been introduced at the 9th grade under the 7th National Curriculum. 4) Uses of the likelihood principle in making a decision and in learning the reliability of it should be encouraged. And students are to team the hazard of transitive inferences in probability comparisons. As a consequence of above, we feel that textbook authors and related stakeholder are to be more serious about the behavioral changes of students that may come along with the didactics of specific contents of school mathematics.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.215-225
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• 2000

Objective : The purpose of this study was to examine the therapeutic compliance and its related factors in the rural hypertensives. Method : A questionnaire survey and blood pressure measurement were performed to 3,876 residents of a rural area, and 660 hypertensives were selected as subjects of study. The study employed a hypothetical model which was composed of constructs from the health belief model and KAP model. The analysis techniques employed included contingency table analysis and structural equation modeling. Result : The proportion of those who were compliant to the treatment of hypertension was 44.2% of subjects. As the result of structural equation modeling, when patients had more favorable attitude toward treatment, higher perceived benefit, or lower perceived barriers to treatment, the therapeutic compliance was significantly higher(T>2.0). When patients had more knowledge about hypertension, or higher perceived severity of hypertension, the attitude toward the treatment of hypertension was more favorable significantly(T>2.0). And when patients had the support for treatment from family or neighbor, the attitude toward treatment was more favorable(T>2.0). When patients had experience of health education, they had more knowledge, higher perceived susceptibility of complication, perceived severity for hypertension, and perceived benefit of treatment, compare to patients without health education(T>2.0). Conclusion : In consideration of above findings, in order to improve the therapeutic compliance in the rural hypertensives, it would be necessary to change attitude, perception, knowledge about hypertension and its treatment, by various methods such as effective health education and programs for maintaining the supportive environment for hypertension treatment.

• Research in Plant Disease
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• v.22 no.3
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• pp.168-177
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• 2016

A forecast model for estimating the infection risk of bacterial canker caused by Pseudomonas syringae pv. actinidiae on kiwifruit leaves in Korea was developed using the generic infection model of Magarey et al. (2005). Two-way contingency table analysis was carried out to evaluate accuracy of forecast models including the model developed in this study for estimating the infection of bacterial canker on kiwifruit using the weather and disease data collected from three kiwifruit orchards at Seogwipo in 2015. All the tested models had more than 80% of probability of detection indicating that all the tested models could be effective to manage the disease. The model developed in this study showed the highest values in proportion of correct (51.1%), probability of detection (90.9%), and critical success index (47.6%). It indicated that the model developed in this study would be the best model for estimating the infection of bacterial wilt on kiwifruit leaves in Korea. The model developed in this study could be used for a part of decision support system for managing bacterial wilt on kiwifruit leaves and help growers to reduce the loss caused by the disease in Korea.