• Journal of Korean society of Dental Hygiene
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• v.1 no.2
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• pp.213-225
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• 2001

Objectives: This study was taken to investigate factors related to dental caries in deciduous teeth of preschool children. Methods : this study was completed by oral examination on 623 kindergarten pupils and questionnaire on their mothers in Sangju city from April 1 to May 20, 2001. Study design is Cross-sectional Study. Results: The mean values for decayed teeth indexed(dt index), filled teeth index(ft index), and decayed and filled teeth index(dft index) was 2.46, 1.85, and 4.30 respectively. 2.05 for girl was significantly lower than 2.77 of boy in gender (p<0.01). As child ren got older, values were higher(0.7 and 2.84 of three years old, 1.6 and 4.01 of four, 2.42 and 5.02 of five) in ft and dft index(p<0.001). Also, Mother age was almost same, that is, 4.12 dft value for 30~34 years was smaller than 6.17 for above forties(p<0.001). 2.07 and 4.68 for mothers who graduated from high school were higher than 1.36 and 3.34 for university in the ft and dft index(p<0.05), that is, the more they had a high educational level, the lower they got a values. Value 2.76 for children who had non cariogenic food was lower than 5.11 for those who had cariogenic food in dft index(p<0.001). In dft index, 3.82 of children who have learned the education on oral health from mother frequently have lower than 45 of children who have never learned (p<0.05). The ft value of children who had a snack food with mother(1.29) was a smaller than children had it at out of home(1.97)(p<0.05). The variables related 10 dft index were children and mothers age, educational level, and kinds of snack food (p<0.05). Conclusion : This study reveals that younger girl, younger mother, higher educational level, and non cariogenic foods showed lower dft index.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.790-794
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• 2007

This paper presents a new index mapping method for DFT (Discrete Fourier Transform) and its application to multidimensional DFT. Unlike conventional index mapping methods such as DIT (Decimation in Time) or DIF (Decimation in Frequency) algorithms, the proposed method is based on two levels of decomposition and it can be very efficiently used for implementing multidimensional DFT as well as 1-dimensional DFT. The proposed pipelined architecture for multidimensional DFT is very flexible so that it can lead to the best tradeoff between performance and hardware requirements. Also, it can be easily extended to higher dimensional DFTs since the number of CEs (Computational Elements) and DCs (Delay Commutators) increase only linearly with the dimension. Various implementation options based on different radices and different pipelining depths will be presented.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.151-157
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• 2016

The purpose of this study was to evaluate the relationship between obesity and dental caries in young children. The subjects were 769 children aged 3 to 6 years, in Iksan, Korea. Body mass index (BMI) and decayed and filled primary teeth (dft) were recorded. Children were classified into four groups (underweight, normal, obese at risk, and obese) according to their BMI percentile. The data of 754 participants, excluding 15 underweight children, were analyzed. The mean dft index was 3.39. There were no significant differences in the number of caries according to gender. The dft index increased significantly with age, with a sharp increase between ages 4 and 5. Children in the obese at risk and obese groups had more caries than those in the normal group. However, there were no statistically significant differences in dft index values between BMI-categorized groups except in 3-year-olds. These findings suggest that there is no significant connection between obesity and dental caries in primary teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.1-13
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• 1999

To study the caries patterns in primary dentition, 719 preschool children, 4-6 years old, were examined for their caries activity(salivary reductase activity) and caries experience of individual teeth. Teeth groups were made by cluster analysis using dft indexes of individual teeth as criteria. The six major teeth groups in the order of dft index from high to low were (1) lower primary molars, (2) upper primary molars, (3) upper central incisor, (4) upper lateral incisor, (5) canines, and (6) lower incisors. There were significant differences in dft index between teeth groups except upper lateral incisor and canines. Upper and lower primary molars showed the highest correlation in dft index, and the next couples were upper central incisors and upper lateral incisors, upper lateral incisor and canines, upper central incisor and canines, upper lateral incisor and upper primary molars, and canines and upper primary molars in descending order. Upper first primary molar showed the greatest differences in dft index between caries activity levels.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.2
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• pp.69-80
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• 2011

Objectives: The purpose of this study was to explore relationship among dft index, diet and oral health behavior, parental awareness in oral health care and social status. Methods: This study was conducted from 8 January, 2009 to 11 June, 2009 in Asan city and Seosan city in Chungnam area. 4 kindergratens, 3 preschools and 1 children language academy were randomly selected to research on dft index, diet and oral health behavior. cross-sectional study conducted among 561 valid samples out of 641 samples collected using the survey was and then followed by oral examination. Throughout the research, numerus SPSS 15.0 statistical techniques, T-test and ANOVA and Spearman correlation coefficients were used for analysis. Results: Key results of the study are as follows: Age was found to be statistically very significant to dft index(p=0.036). Age of mother, especially between 30 to 49, was found to be statistically significant to dft index rate(p=0.001). Occupation of father was also found to be statistically significant to dft index(p=0.036). High parental awareness in oral health care led to low dft index rate, which also was found to be statistically significant(p=0.036). Conclusions: In conclusion, as Spearman correlation coefficient demonstrates, occupation of father affects most on long-term healthy oral behavior followed by parental awareness in oral health care and age of mother.

• Journal of Korean society of Dental Hygiene
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• v.10 no.1
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• pp.215-229
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• 2010

Objectives : This study was to assess the children's mean number of decayed or filled primary teeth in relation to their mother's oral health behavior and then to increase children's oral health. Methods : The 346 children and their mothers were selected for this study. The children were 4 or 7 years old in the 4 dental clinics in Busan and Kyungnam, Korea. Data were collected by examination on children and self-administrated questionnaire on their mothers. The questionnaire was surveyed mother's oral health behaviour and children experienced dental caries or not and the number of decayed or filled they had were used as outcome variables. Results : 1. The mother's education level affected children's dft index significantly(p<0.05), In the case of tooth brushing method of children, the group with circle teeth wipes shows the low dft index(p<0.01). 2. On the other hand the group with snack as food eaten between meals has high dft index(p<0.001). 3. The group with mother's visiting to dentist within recent 1 year, experience in removing plaque or willing to attend the oral health education show low dft index(p<0.05). The important variables affecting to dft index are experience with oral health education, tooth brushing guidance, replacement of toothbrushes, the kind of food eaten between meals, recent experience of plaque removal and willing to participating in the oral health class. Conclusions : This study showed that the mother's oral health behavior and concern play an important role for the prevention of preschooler's dental caries. Dental health education would be focused on the mothers, expecially for the practice of preventive behavior by preschools themselves.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1505-1514
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• 2004

Sequence matching in time-series databases is an operation that finds the data sequences whose changing patterns are similar to that of a query sequence. Typically, sequence matching hires a multi-dimensional index for its efficient processing. In order to alleviate the dimensionality curse problem of the multi-dimensional index in high-dimensional cases, the previous methods for sequence matching apply the Discrete Fourier Transform(DFT) to data sequences, and take only the first two or three DFT coefficients as organizing attributes of the multi-dimensional index. This paper first points out the problems in such simple methods taking the firs two or three coefficients, and proposes a novel solution to construct the optimal multi -dimensional index. The proposed method analyzes the characteristics of a target database, and identifies the organizing attributes having the best discrimination power based on the analysis. It also determines the optimal number of organizing attributes for efficient sequence matching by using a cost model. To show the effectiveness of the proposed method, we perform a series of experiments. The results show that the Proposed method outperforms the previous ones significantly.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.318-327
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• 2002

The purpose of this study was to make a comprehensive study and to provide information about the dental caries and plaque index of cerebral person, and to aid improvement of their oral health. The author examined intraorally 1180 deciduous teeth, 5626 permanent teeth of 264 (male:153 female:111) cerebral palsy person and 1526 deciduous teeth, 4140 permanent teeth of 220 (male:125 female:95) non cerebral palsy person as the control group. The results were as follows : 1. Cerebral palsy persons Had higher dft rate than non-cerebral palsy persons. 2. Dental caries incidence between males and females in cerebral palsy persons showed no difference, and dental caries incidence of types in cerebral palsy person showed no difference, either. 3. Mental, motor, speech handicap degrees were negatively related to DMFT rate and DMFT index, and institutionalized cerebral palsy persons and cerebral palsy persons of which parent's occupation is private business were found low DMFT rate and DMFT index. 4. Cerebral palsy persons were found to have higher plaque index than non-cerebral palsy persons, and non institutionalized cerebral palsy persons and self-supported cerebral palsy persons were found high plaque index. 5. Plaque index of male and female in cerebral palsy person showed no difference, and Plaque index of types in cerebral palsy person showed no difference, either Plaque index of handicap degrees(mental, motor, speech) showed no difference.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.25-31
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• 1999

The purpose of study was to test the hypothesis that preschool children who experienced nursing caries have high dft index and caries activity in primary dentition. One thousand and seventy-five preschool children from 4 to 6 years old were examined for their caries experience and salivary invertase activity by Resazurin Disc Test. Nursing caries group was identified by the criteria of having more decayed and filled teeth among the upper incisors than among the upper molars. The prevalence of nursing caries was 15.8%. The dft index of nursing caries group was significantly higher than that of the other groups except the rampant caries group(P<0.01). The Resazurin Disc Test score of nursing caries group was significantly higher than that of the other groups(P<0.01) and there was no difference between nursing caries group and rampant caries group. Therefore, it is recommended that children who experienced nursing caries should be incorporated in the caries prevention program through the primary and mixed dentition.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.371-378
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• 2014

This study aims to evaluate the influence of vitamin and mineral supplement intake, and degree of calcium and phosphorus intake on occurrence of dental caries in primary teeth. Research data was derived from the Fourth Korean National Health and Nutrition Examination Survey (KNHANES) and 1,139 Korean children of 3 to 6 years were selected as subject for this study. The dft index, nutrition factor including vitamin or mineral supplement intake and degree of intake for calcium (Ca) and phosphorus (P) were identified. Chi-square test was performed to assess the difference in socioeconomic status, oral health behavior and nutrition factor, including vitamin or mineral supplement intake and degree of intake for Ca and P. Linear regression analysis was performed to identify the relationship between the dft index and the related variables. As a result, the dft index was increased with the age. Significant differences in Ca intake was examined according to the sex, and P intake was different according to the sex in 3-year-old group. Among the 4-year-old children, the vitamin and mineral supplement takers had 1.206 less dft index than the non-takers. In conclusion, intake of Ca, P and vitamin/mineral supplement was not a pivotal factor to influence the incidence of primary teeth caries. However, significantly low dft index was observed from 4-year-old group who intake vitamin or mineral.