새로운 이중 색인 사상에 의한 다차원 DFT의 파이프라인 구조 개발

庾盛郁(Sungwook Yu) 대한전기학회 2007 전기학회논문지 Vol.56 No.4

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 l-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.

시퀀스 데이터웨어하우스에서 이산푸리에변환과 비트맵을 이용한 시퀀스 스트림 색인 기법

손동원(Dong-won Son),홍동권(Dong-Kweon Hong) 한국지능시스템학회 2012 한국지능시스템학회논문지 Vol.22 No.2

최근 시각적으로 변화된 데이터에서 유사한 값의 움직임 즉 유사 패턴을 검색하는 연구가 활발히 진행되고 있다. 시간적으로 변화된 데이터는 시계열 데이터(time series data) 또는 시퀀스 데이터(sequences data)로 분류되며 기존의 스칼라 값을 가지는 데이터와는 매우 다른 의미를 가진다. 본 눈문에서 유사 시퀀스 검색은 시퀀스 데이터웨어하우스에서 값의 변화가 유사한 형태를 가지는 시퀀스들을 검색한다. 유사 시퀀스를 검색하기 위하여 본 논문에서는 먼저 시퀀스 원시 데이터에 이산 푸리에 변환(DFT, Discrete Fourier Transform)을 적용하여 데이터를 변환한다. 변환된 데이터는 그 특성으로 인하여 유사 패턴의 검색에 적합하며 또 유사도를 비교할 때 일부분만 사용되므로 색인에 사용되는 속성의 개수를 줄이는 장점이 있다. 또 데이터웨어하우스 환경이므로 더 좋은 성능을 보일 수 있는 비트맵 색인 기법을 적용하였다. 시퀀스 데이터의 효율적인 검색을 위하여 영역 지정 검색 방법을 제안하고 효율적인 실행을 위한 비트맵을 활용한 다양한 조합의 색인을 생성하고, 질의 최적화기의 연산 비용을 비교하면서 효율적인 검색 연산을 위한 최저 비용의 색인을 선택하는 기법을 연구하였다. Recently there has been many active researches on searching similar sequences from data generated with the passage of time. Those data are time series data or sequence data and have different semantics from scalar data of traditional databases. In this paper similar sequences that have a similar trend of value changes. At first we have transformed the original sequences by applying DFT. The converted data are more suitable for trend analysis and they require less number of attributes for sequence comparisons. In addition we have developed a region-based query and we applied bitmap indexes which could show better performance in data warehouse. We have built bitmap indexes with varying number of attributes and we have found the least cost query plans for efficient similar sequence searches.

어머니의 구강보건관리행태와 자녀의 우식경험유치지수와의 관련성

장경애 ( Kyeung Ae Jang ),김동열 ( Dong Yeol Kim ) 한국치위생학회 2010 한국치위생학회지 Vol.10 No.1

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.

비타민 및 무기질 섭취와 유치우식과의 관련성

김한나 ( Han Na Kim ),민지현 ( Ji Hyun Min ),김기림 ( Ki Rim Kim ) 한국치위생과학회 2014 치위생과학회지 Vol.14 No.3

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.

치아별 우식경험도로 본 유치열의 우식패턴에 관한 연구

김대업,이광희,이종선 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.1

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 froups were made by cluster analysis using dft 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 incisous, upper lateral incisor 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.

학령전기 아동의 치아우식증 발생에 영향을 미치는 요인 조사 - 충남 일부지역 아동을 중심으로 -

배성숙,노희진 한국학교・지역보건교육학회 2011 한국학교지역보건교육학회지 Vol.12 No.2

1989-2000년의 5, 12세 한국아동의 치아우식실태에 관한 조사연구

이춘희,최충호,권호근 대한구강보건학회 2003 大韓口腔保健學會誌 Vol.27 No.1

The objective of this study was to analize the change of dental caries prevalence in Korean children and adolescents from 1989 to 2000. National oral examination survey reports in 1989,1991,1995 and 2000 were collected for this purpose The major finding were summerized and the results were as follows : 1. The dft of 5-year-old children in creased from 1989 to 1995 and decreased slightly from 1995 to 2000 the dt decreased or remained constant and the ft increased. 2. The dt of 5-year-olds decreased constantly by 1991 in rural area but in urban area, it remained stable by 1991 and the ft increased in rural and urban area. 3. The DMFT of 12-year-old children increased from 1989 to 2000 the DT decreased of remanined constant and the FT increased, the MT remained below 0.05 4. The DT index of 12-year-olds decreased constantly by 1991 in rural area but in urban area, it remained stable by 1991 and FT index increased in rural and urban area 5. The percentage of caries free and caries experience have increased in rural and urban area. According to results the dft of 5-year-olds and the DMFT of 12-year-olds have increased specially among the component of dft and DMFT dt and DT decreased or remain stable while ft and FT increased constantly which means that the restorative index(ft/dft, FT/DMFT) increased also and the percentage of caries experience increased. Based on this study, preventive approach is more required to lower caries prevalence of korean childeren

우유병 우식증을 경험한 아동의 우식유병률과 우식활성에 관한 연구

이광희 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.1

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.

Cariostat를 이용한 아동의 우식활성에 관한 임상적 연구

김재곤,이영수,양정숙,양연미,백병주 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.3

The purpose of the study was to determine the ability of the caries activity test, 'Car-iostat'to identify preschool children with dental caries, The subjects of this study were 76 children of 3 to 5 years of age. Oral examination was carried out to out to assess the caries experience using a mirror and explorer. In all subjects buccal plaque samples were obtained, incubated. and scored as the manufacturer's instructions for the cariostat test. statistical analyses were used with the Crosstabulation. The test group exhibited mean dft index 5.21, while 27.63% of subjects were caries free and had no restorations. The sensitivity of the Cariostat test was found to be 98.8% while the specifioity was found to be 19.05% The results showed that caries activity measured by visual reading was highly significant to the Cariostat score and dft index(P<0.001). the Cariostat method has indicated the future possible occurrence of caries. The use of this method is meant to require in the caries prevention program.

Cariostat를 이용한 아동의 우식활동에 관한 임상적 연구

백병주,양정숙,이영수,양연미,김재곤,Baik, Byeong-Ju,Yang, Jeong-Suk,Lee, Young-Su,Yang, Yeon-Mi,Kim, Jae-Gon 대한소아치과학회 1998 大韓小兒齒科學會誌 Vol.25 No.3

The purpose of the study was to determine the ability of the caries activity test, 'Cariostat' to identify preschool children with dental caries. The subjects of this study were 76 children of 3 to 5 years of age. Oral examination was carried out to assess the caries experience using a mirror and explorer. In all subjects buccal plaque samples were obtained, incubated, and scored as the manufacturer's instructions for the Cariostat test. Statistical analyses were used with the Crosstabulation. The test group exhibited mean dft index 5.21, while 27.63% of subjects were caries free and had no restorations. The sensitivity of the Cariostat test was found to be 98.8% while the specificity was found to be 19.05% The results showed that caries activity measured by visual reading was highly significant to the Cariostat score and dft index(P<0.001). The Cariostat method has indicated the future possible occurrence of caries. The use of this method is meant to require in the caries prevention program.