• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권4호
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• pp.397-410
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• 2000

Skeletal class III had been classified by the position of the maxilla, the mandible, the maxillary alveolus, the mandibular alveolus and vertical development. This morphologic approach is simple and useful for clinical use, but it is insufficient to permit understanding of the pathophysiology of dysmorphoses. The author hypothesizes that there are different patterns of mutual relation of the skeletal components which have contributed pathologic equilibrium of skeletal class III. The purpose of this study are threefold: 1) to classify skeletal class III in subgroups, which can show the architectural characteristics of the deformity, 2) to analyse the craniofacial architecture of each subgroup on etio-pathogenic basis, and 3) to characterize and visualize the pattern as a prototype. Materials used in this study were lateral cephalograms of 106 skeletal class III adults, which were analysed with modified Delaire's architectural and structural analysis. Linear and angular measurements of the individual subject were obtained and cluster analysis was used for the subgrouping. Data were evaluated for verification of the statistical significances. The following results were obtained. 1. By the modified Delaire's architectural and structural analysis and cluster analysis, skeletal class III adults were classified into 7 clusters and presented as prototypes, which could show the pathophysiology of the skeletal architecture 2. There was significant relationship in measurement variables of each cluster, which could reflect characteristics of the skeletal pattern of growth. 3. The flexure of cranial base had a close relationship to the anterior rotational growth of the maxilla and contributes to understand the etio-pathology of skeletal class III. 4. The proportion of craniospinal area in cranial depth, craniocervical angle and vertical position of point Om had a close relationship to rotational growth of the mandible and direction of condylar growth. They contribute to understand the etio-pathology of skeletal class III. In summary, the cranium and the craniocervical area must be considered in diagnosis and treatment planning of dentofacial deformity. And the occlusal plane can be considered as a representative which shows the mutual relationships of the skeletal components.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.131-138
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• 1981

The purpose of this study was to evaluate the marginal leakage of composite resin. Preparing 144 class V cavities on freshly extracted noncarious teeth, composite resins were prepared and inserted by one dentist according to the manufacturer's instructions. The experiments were performed in two different groups; In group I; Class V cavities with $90^{\circ}$ cavosurface angle, In group II; Class V cavities with $135^{\circ}$ cavosurface angle. And each group was divided 2 subgroups; In control group; composite resin restoraions without acid etch technique. In experimental group; composite resin restorations with acid etch technique. All specimens were immersed in 0.05% crystal violet solution. Before examination, the restored teeth were subjected to thermal stress. The specimens were sectioned occlusogingivally through the center of the restorations with a diamond disk. The sections were examined under a reflected light microscope at 1 day, 7 days and 30 days after immersing the specimens in dye solution. The results were as follows; 1. Control group of group I and group II showed marginal leakage. 2. The degree of marginal leakage in experimental group was greater reduced than control group. 3. In control group, the degree of marginal leakage in group I was greater than group II. 4. In experimental group, there is not statistical differences of the degree of marginal leakage between group I & group II.

• Communications for Statistical Applications and Methods
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• 제23권2호
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• pp.131-146
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• 2016

In research on behavioral studies, significant attention has been paid to the stage-sequential process for longitudinal data. Latent class profile analysis (LCPA) is an useful method to study sequential patterns of the behavioral development by the two-step identification process: identifying a small number of latent classes at each measurement occasion and two or more homogeneous subgroups in which individuals exhibit a similar sequence of latent class membership over time. Maximum likelihood (ML) estimates for LCPA are easily obtained by expectation-maximization (EM) algorithm, and Bayesian inference can be implemented via Markov chain Monte Carlo (MCMC). However, unusual properties in the likelihood of LCPA can cause difficulties in ML and Bayesian inference as well as estimation in small samples. This article describes and addresses erratic problems that involve conventional ML and Bayesian estimates for LCPA with small samples. We argue that these problems can be alleviated with a small amount of prior input. This study evaluates the performance of likelihood and MCMC-based estimates with the proposed prior in drawing inference over repeated sampling. Our simulation shows that estimates from the proposed methods perform better than those from the conventional ML and Bayesian method.

• 대한간호학회지
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• 제35권8호
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• pp.1500-1507
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• 2005

Purpose. The purpose of this study was to identify subgroups of the physical and behavioral risk profiles for cardiovascular disease among industrial workers, and to examine predicting factors for the subgroups. Sample and Method. Health records of 2,616 male and female workers aged 19-56 years who were employed in an airplane manufacturing industry were analyzed. Data were analyzed using the Latent class cluster analysis. Results. Four different clusters (two high-risk groups, one low-risk group, and one normal group) were found and these clusters were significantly different by age, gender, and work type (p < .05 ). The two high-risk groups had higher chances of drinking alcohol, elevated BMI, FBS, total cholesterol, having hypertension, and were significantly older, and had relatively high chances of being day workers rather than other groups. The low-risk group had higher chances of drinking alcohol, higher BMI and total cholesterols compared to normal group, and highest portions of current smokers and shift workers in the four clusters and their mean BP was within prehypertension criteria. Conclusion. Industrial nurses should guide the lifestyle behaviors and risk factors of the high risk groups for CVD and need to intervene early for behavioral change for the low-risk group who are young and shift workers. Age, and work environment should be considered in planning for targeted preventive interventions for industrial workers.

• 대한치과교정학회지
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• 제26권5호
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• pp.509-522
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• 1996

하악골 성장양상이 진단과 치료, 치료후 예후에 특히 중요한 III급 부정교합자에 있어 그 성장양상을 예측하는데 도움을 주고자 사춘기 전으로 생각되는 남자 10-12세군(G1군)과 악골성장이 거의 끝난 것으로 생각되는 성인으로 남자 20세 이상군(G2군)에 대하여 각각 이부비율에 따라 다시 3군으로 분류하고 이부형태와 두개안면형태의 연관성을 연구 한 결과 다음과 같은 결론을 얻었다. 1. 평균 이부비율에 있어 G2군이 G1군에 비해 통계학적으로 유의성 있게 크게 나타났다(p<0.05). 2. G1군과 G2군 모두 이부비율과 두개저 계측항목과는 상관성이 없었다(P>0.05). 3. 상하악골의 수평적 관계 계측항목에서 G1군과 G2군 모두 이부비율과 상악골 계측항목과는 상관성이 없었다(p>0.05). 또한 G1군과 G2군 모두 L, A, S군간 하악의 전후적 위치는 뚜렷한 차이가 없고, 단지 G1군의 Y-axis angle에서 L군이 S군에 비해 크고 G2군은 Pog to Na perp.에서 S군이 L군에 비해 통계학적으로 유의성 있게 크게 나타났다(p<0.05). 4. 하악골의 형태 계측항목에서 gonial angle은 G1군과 G2군 모두 이부비율이 클 수록 수치적으로 증가하나 통계학적인 유의성은 없었다(p>0.05). Lower genial angle과 chin angle은 G1군에서 L군과 A군이 S군보다 통계학적으로 유의성 있게 크게 나타났다(p<0.05). 5. 안면의 수직적 관계 계측항목에서 G1군은 L군이 S군에 비해 전안면고경, 전하안면고경이 통계학적으로 유의성 있게 크며(p<0.05) 하악골이 하방성장한 경향을 보여주었다. 6. 치아의 위치 및 경사도 계측항목에서 G1군은 하방성장을 많이 한 L군이 S군에 비해 상하악 치아들이 정출되어 있는 경향을 보여주었지만 G2군은 단지 하악치아 만이 그러한 경향이 있었다. 7. 이부비율과 다른 계측항목과의 상관분석에서 G1군은 chin angle, PP/MP angle, ANS-Me등 많은 계측항목에서 G2군은 단지 MP-LIT와 MP-LMMC에서 통계학적으로 유의성 있는 상관성을 보였다(p<0.05, p<0.01). 이상을 종합하면 어린 남자군인 G1군에서는 이부비율이 큰 군(L군)과 작은 군(S군)사이에 수평적 골격관계는 차이가 없으나 수직적 골격관계는 L군이 S군에 비해 하악골이 하방으로 많이 성장한 경향을 보여주었다. 하지만 성인 남자군인 G2군에서는 이부비율에 따른 안면골격의 뚜렷한 형태적 차이를 보여주지 않았다.

• 대한치과교정학회지
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• 제39권3호
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• pp.136-145
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• 2009

상기도 공간은 3차원 입체 구조물로서 두부규격방사선사진 등으로 분석하기에는 평가의 한계가 존재하였다. 본 연구는 최근 방사선 피폭량 등의 감소로 그 활용도가 높아진 cone beam CT (CBCT)를 이용하여 안면골격형태에 따른 상기도 공간의 면적, 전후방 폭경 및 측방 폭경을 측정하고 그 관련성을 알아보았다. 102명을 대상으로 CBCT (VCT, Vatech, Seoul, Korea)를 촬영하였으며, FH plane에 평행하면서 aa point (the most anterior point on the anterior arch of atlas), $CV_{2ia}$, $CV_{3ia}$ point (most infero-anterior point on the body of the second & third cervical vertebra)를 지나는 평면을 기준으로 설정하였다. 각 항목의 계측치는 one-way ANOVA를 이용하여 통계처리하고 Duncan test로 사후검정하였다. 연구 결과, 안면 골격형태에 따른 측방 폭경에는 유의한 차이가 없었다. Group 2 (Class II) 집단은 aa plane, $CV_2$ plane, $CV_3$ plane에 의해 형성된 상기도 공간의 단면적이 좁았으며, 전후방 폭경도 Group 3 (Class III)에 비해 유의성 있게 좁았다. 수직 안면골격형태와 정상 안면골격 형태간의 유의성 있는 차이는 없었으나, aa plane에서 형성된 상기도 공간의 전후방 폭경은 Group 1V (Class I vertical)가 Group 1N (Class I normal)에 비해 유의성 있게 좁은 것으로 나타났다 (p < 0.05).

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.37.2-37.2
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• 2009

In this study, we present a new empirical forecasting method of solar proton events based on flare parameters. For this we used NOAA solar energetic particle (SEP) events from 1976 to 2006 and their associated X-ray flare data. As a result, we found that about only 3.5% (1.9% for M-class and 21.3% for X-class) of the flares are associated with the proton events. It is also found that this fraction strongly depends on longitude; for example, the fraction for $30W^{\circ}$ < L < $90W^{\circ}$ is about three times larger than that for $30^{\circ}E$ < L < $90^{\circ}E$. The occurrence probability of solar proton events for flares with long duration (> 0.3 hours) is about 2 (X-class flare) to 7 (M-class flare) times larger than that for flares with short duration (< 0.3 hours). The relationship between X-ray flare peak flux and proton peak flux as well as its correlation coefficient are strongly dependent on longitude. Using these results for prediction of proton flux, we divided the data into 6 subgroups depending on two parameters: (1) 3 longitude ranges (east, center, and west) and (2) flare impulsive times (long and short). For each subgroup, we make a linear regression between the X-ray flare peak flux and the corresponding proton peak flux. The result shows that the proton flux in the eastern region is much better correlated with the X-ray flux than that in the western region.

• 대한음성학회지:말소리
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• 제21_24호
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• pp.144-175
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• 1992

This paper aims to discuss determining factors of Korean allophones and to formulate and classify Korean allophonic rules systematically. The relationship between allophones and coarticulation, the most. influential factor of allophonic variation, is thoroughly investigated. Other factors -- speech tempo and style, dialect, and social factors such as age, set, class etc. -- are also briefly discussed. Allophonic rules are classified into two groups -- 3) those relevant to coarticulation and 2) those irrelevant to coarticulation. Rules of the first group are further classified into four subgroups according to the directionality of the coarticulation. Each allophonic nile formulation is explained and discussed in detai1. The allophonic rules formulated and classified in this paper are 1) Devoicing of Voiced Consonants, 2) Devoicing of Vowels, 3) Nasal Approach and Lateral Approach, 4) Uvularization, 5) Palatalization, 6) Voicing of Voiceless Lax Consonants, 7) Frication, 8) Labialization, 9) Nasalization, 10) Release Withholding and Release Masking, 11) Glottalization, 12) Flap Rule, 13) Vowel Weakening, and 14) Allophones of /ㅚ, ㅟ, ㅢ/ (which are realized as diphthongs or as monophthongs depending on phonetic contexts).

• 지역사회간호학회지
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• 제31권2호
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• pp.212-221
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• 2020

Purpose: This study aims to identify the types of health-related quality of life (QoL) based on the EuroQoL 5 Dimensions among community older people and predict the factors affecting these types. Methods: This study used data from the 2016 Korea Health Panel Survey, whose participants included 3,848 older people. The data were analyzed using the software jamovi 1.2.17 and Mplus 8.2 for latent class analysis. Results: The subgroups of the older people's health-related QoL were identified as three latent classes: General stable type (43.9%), pain-related low type (35.0%), and general low type (21.1%). The types and characteristics of health-related QoL among the latent classes differed. Comparing the difference between the general low type and general stable type, the subjects showed higher probability of belonging to the general stable type when they were men, younger, higher education level, employment, better subjective health, lower BMI and stress level, and no suicidal ideation. A comparison between the general low type and the pain-related low type showed that the subjects were more likely to be classified as the pain-related low type when they were younger, higher education, employment, and better subjective health. Conclusion: The results showed a significant heterogeneity in the types of health-related QoL among community older people, and the predictors for each type were not the same. These findings present basic data for cultivating nursing interventions that enhance health-related QoL.

• 대한소아치과학회지
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• 제48권2호
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• pp.140-150
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• 2021

이번 연구는 2017 - 2019년에 서울대학교치과병원 소아치과에 내원하여 교정 진단을 받은 580명의 환자를 대상으로 조사를 시행하였다. 이 연구는 소아치과에 내원하는 교정환자의 골격 형태를 측모두부방사선 분석으로 파악하고 골격 형태와 관련된 임상적 특징과의 상관관계를 분석하고자 하였다. 또한, 골격 형태에 따라 행해진 치료방법에 대해 조사하여 임상의가 교정치료 계획 수립시 도움이 되고자 시행되었다. 연령분포는 7세 연령군이 교정진단을 받은 환자 중 가장 많은 분포를 차지하였다. 골격분포는 골격성 1급 부정교합이 54.2%로 가장 많았고 2급은 22.2%, 3급은 23.6%를 차지하였다. 골격성 1급의 경우 상하악 모두 후퇴인 환자가 34.4%, 골격성 2급의 경우 상악은 정상범주이나 하악이 후퇴인 경우가 39.5%, 골격성 3급의 경우 상악 후퇴 및 하악 전돌이 35.0%로 가장 높은 비율을 보였다. 수직적 골격형태는 brachyfacial type이 55%으로 가장 많았고 mesofacial type은 31.9%, dolichofacial type은 13.1%로 나타났다. 전체 환자 중 43.3%가 전치부 반대교합을 보였다.