• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.6
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• pp.496-501
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• 2011

The missing data patterns of tidal elevation data in Korean coasts are analysed and provided. The missing interval of the data is displayed for all stations using the missing data indicator matrix in order to identify the overall missing pattern. The spatial and temporal missing rates are also estimated. The total missing rate of tidal elevation data is low. However, most of the missing is mainly derived from just 1 or 2 specific stations. The autocorrelation function of the consecutive missing interval data also shows that the missing interval occurs randomly.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.675-686
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• 2009

In this paper, it will be assumed that there are two distinct populations which are multivariate normal with equal covariance matrix. We also assume that the two populations are equally likely and the costs of misclassification are equal. The classification rule depends on the situation when the training samples include missing values or not. We consider the bootstrap confidence intervals for classification error rate when a block of observation is missing.

• Journal of Ginseng Research
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• v.22 no.4
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• pp.294-298
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• 1998

This study was conducted to investigate the effects of growth characteristics and mineral contents of ginseng seedling grown in different locations on ginseng growth and root yield. Ginseng seedling produced in 16 farmers' field at the semi-Yangjik seedbed were planted and cultivated in a field with same cultural practices. Missing plant was increased with increased year of ginseng age, especially severe at 5-year-old ginseng. Rate of missing plant was different among the origins of the seedling, even with the same weights. Negative correlation was noted between the missing rate of 3-year-old ginseng plants and NH4-N content of the seedling, but positive correlation between the missing rate and K2O and Ca contents of the seedling. Root yield of 6-year-old ginseng was also affected by the origins of ginseng seedlings. Root yield was high in ginseng plant from 0.6∼0.9 g see dings compared to those from over 0.9 g seedlings.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.539-547
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• 2016

We discussed how to handle missing binary data clinical trials. Patterns of occurring missing data are discussed and introduce missing binary data imputation methods that include the modified method. A simulation is performed by modifying actual data for each method. The condition of this simulation is controlled by a response rate and a missing value rate. We list the simulation results for each method and discussed them at the end of this paper.

• Journal of the Korean Data and Information Science Society
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• v.20 no.4
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• pp.757-764
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• 2009

In discriminant analysis, we consider a special pattern which contains a block of missing observations. We assume that the two populations are equally likely and the costs of misclassification are equal. In this situation, we consider the bootstrap confidence intervals of the error rate in the circular models when the covariance matrices are equal and not equal.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.303-314
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• 1993

The purpose of this study was to find out the prevalence of dental anomalies in 600 normal persons (male:363, female:237) at age 14 to 39 years, through history taking, oral examination, and radiographic observations of subjects. The obtained results were as follows: 1. The prevalences of individual dental anomalies were as follows; Congenitally missing teeth 7%; supernumerary teeth 1.33%; ectopic eruption; 8.50%, transposition;0.33% rotation; 23.67%, microdontia;11.16%(peg lateralis;5.33%, third molar;5.83%), prolonged retention of deciduous teeth;1.33%, crowding 49.83%, and spacing;15.17%. 2. Alterations in numbers of teeth : The most frequently missing teeth were mandibular lateral incisors, followed by mandibular second premolars and maxillary second premolars. In numbers of congenitally missing teeth per person, 52.38% had one missing tooth and 30.95% had two missing teeth. In supernumerary teeth, there was higher rate in male than in female. Most supernumerary teeth were mesiodens of median area in maxilla and the eruption pattern of that teeth generally was unerupted state. 3. In transposition, exchange of position of teeth involved the canine and first premolar. 4. Congenital missing rate of permanent successors in prolonged retention of deciduous teeth was 69.23%. 5. Crowing and spacing had respectively higher rate in mandible and in maxilla.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.45-51
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• 1993

In 61 abolished ginseng fields examined in 1986, the average plant missing was 49.2%, root rusting, 34.4%, and root rot, 3.3%. Plant missing was not different among the ages of ginseng fields; however, rate of root rusting was high in 3- and 4-year-old ginseng fields, and rate of root rot was high in 5- and 6-year-old ginseng fields, suggesting that root rusting and root rot were relatively more important factors related to the abolishment of ginseng filed in younger and older ginseng fields in 1986, respectively. Out of 61 ginseng fields, 18 were infested with more than 509) alternaria blights, and out of 19 fields with root rot, 2 were caused by Sclerotinia sp., 5 by potato rot nematode, and the causal agents were not identified in 12 fields. With increase of the ridge height, root rusting was significantly decreased, and plant missing rate was significantly lower in fields with straw mulching than those without mulching. The physico-chemical characteristics of the fields with more than 50fi root rusting, the contents of $NO_3,\;P_2O_5$ and Ca were higher than those of good fields with less than 40% root rusting and plant missing. The population of Erwinia sp. was significantly corralled with plant missing.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.235-249
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• 2012

Objectives : The purpose of this research is to use data from the third year of the 4th National Health and Nutrition Examination Survey to study relationship between oral disease and chronic disease that generally persist from 6 months to over a year, or more specifically, circulatory disease, diabetes, and osteoporosis. Methods : Of the data from the third year of the 4th National Health and Nutrition Examination Survey, 7,893 adults over 19 years old who completed medical examination, health survey, and nutrition survey were selected as the final research subjects. Relationship between chronic disease and oral disease was analyzed by cross tabulation (2-test) and logistic regression analysis using SPSSWIN ver 18.0. Results : 1. Differences in the rate of prevalence of periodontal disease and the rate of prevalence of missing teeth were statistically significant with respect to age, gender, marital status, education level, residential area, income level, and occupation. Rate of prevalence of dental caries was statistically significant with respect to age, education level, and income level. 2. After examining the relationship between existence of chronic disease as diagnosed by doctor with oral disease, rate of prevalence of periodontal disease and missing teeth, hypertension, hyperlipidemia, stroke, myocardial infarction, angina, diabetes, and osteoporosis showed statiscally significant difference. 3. Examination of rate of prevalence of chronic disease with respect to oral disease, periodontal disease and missing teeth exerted statistically significant influence on hypertension, hyperlipidemia, stroke, myocardial infarction, angina, diabetes, and osteoporosis (p<0.05), while dental caries did not have statistically significant effect. 4. Analysis of coupling effect of periodontal disease and missing teeth on chronic disease showed that they were related in all chronic diseases examined in this study (hypertension, hyperlipidemia, stroke, myocardial infarction, angina, diabetes, and osteoporosis) (p<0.05). Conclusions : Periodontal disease and missing teeth were found to increase the rate of prevalence of chronic disease.

• Journal of Ginseng Research
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• v.9 no.1
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• pp.36-41
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• 1985

The study was conducted to investigate the changes of soil physico-chemical properties between soils of preplanting fields and 2 years old ginseng fields, and compare the missing plant rate among the 2 years 016 ginseng fields. 1, The missing plant rate of 2 years old ginseng was high in sand loam while low in clay loam soil texture, soil porosity and NO3-N were remarkably increased in 2 years old ginseng field than preplanting soil, as the clay content was increased, soil porosity seemed to be increased but exchangeable nitrogen decreased. 2. The preplanting soil management methods did not significantly influenced on the missing plant rate and soil porosity in 2 years old ginseng fields, However NO3-N content and Fusarium density seemed to be decreased as the plow frequency was increased, exchangeable nitrogen content, whereas, seemed to be increased with more organic matter. 3. Differences of clay content (below 15% and above 20% of clay content) was significantly influenced on soil porosity, bulk density, total nitrogen, organic matter and P2O5 content. 4, Missing rate showed negative correlation with clay, soil moisture, and organic matter content but positive corelation with NO3-N in 2 years old ginseng fields.

• Journal of the Korean Data and Information Science Society
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• v.24 no.1
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• pp.189-200
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• 2013

In this paper, it will be assumed that there are two distinct populations which are multivariate normal with equal covariance matrix. We also assume that the two populations are equally likely and the costs of misclassification are equal. The classification rule depends on the situation whether the training samples include missing values or not. We consider the conditional bootstrap confidence intervals for classification error rate when a block of observation is missing.