• Journal of Yeungnam Medical Science
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• 제39권4호
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• pp.285-293
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• 2022

Background: This study was conducted to analyze the effects of low skeletal muscle mass index (SMI) and obesity on aging-related osteoarthritis (OA) in the Korean population. Methods: A total of 16,601 participants who underwent a dual-energy X-ray absorptiometry and 3,976 subjects with knee X-rays according to the modified Kellgren-Lawrence (KL) system were enrolled. Knees of ≥KL grade 2 were classified as radiologic OA. The severity of joint space narrowing (JSN) was classified by X-rays as normal, mild-to-moderate, and severe JSN in radiologic OA. The subjects were grouped as normal SMI (SMI of ≥-1 standard deviation [SD] of the mean), low SMI class I (SMI of ≥-2 SDs and <-1 SD), and low SMI class II (SMI of <-2 SDs). Obesity was defined as a body mass index (BMI) of ≥27.5 kg/m². Results: The modified KL grade and JSN severity were negatively correlated with the SMI and positively correlated with BMI and age. The SMI was negatively correlated with age. JSN severity was significantly associated with a low SMI class compared to a normal SMI, which was more prominent in low SMI class II than class I. Obesity was significantly associated with more severe JSN, only for obesity with a low SMI class. Furthermore, patients with a low SMI class, regardless of obesity, were prone to having more severe JSN. Conclusion: This study suggested that a low SMI class was associated with aging and that an age-related low SMI was more critically related to the severity of JSN in OA.

• Journal of Forest and Environmental Science
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• 제30권1호
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• pp.101-106
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• 2014

The purpose of this research was to figure out the stand structure and growth characteristic with relation to DBH, height, and volume in sixteen Pinus koraiensis plantations of Gangwon province region. Age class was diversely distributed from age class II (16 yr) to age class VIII (77 yr), and, in terms of site index, sixteen regions were superior: nine regions 'high', seven regions 'middle'. The distribution of DBH by sites appeared a bell-shaped curve, and the number of trees was the most in diameter section of 18-22 cm. The dispersion of DBH was various with age and widest ranging from 18 cm to 58 cm in age class VII-VIII. The distribution of height was also a bell-shaped curve with the smaller deviation than the distribution of DBH, and most of trees were in height section of 14-18 m. The correlation of DBH and height was high (r=0.75), and the volume bigger than 1.0 $m^3$ was presented from DBH 35 cm, height 20 m.

• 가정과삶의질연구
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• 제29권1호
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• pp.111-126
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• 2011

The aim of the present study was to compare child care center directors and teachers' recognition of criteria for class placements, specifically for children who were born in January or February, children's ability, and for mixed-age classes. The subjects were 398 center directors and 383 teachers in Seoul, Gyeonggi-do, Jeolla-do, Gangwon-do, Choongcheong-do and Gyeongsang-do. Data were analyzed by SPSS 12.0 and the t-test and Chi-square test were used. The results were as follows: (1) Most child care center directors and teachers believed that children born in January or February should share a classroom with classmates of the same age. (2) Most child care center directors and teachers believed that regardless of a child's ability, it was desirable for the child to be in a class with classmates of the same age. (3) Child care center directors thought that the current criteria for teacher-child ratios within a mixed-age classroom were acceptable but should be lowered if the child care center was not experiencing financial problems. Meanwhile, most of the teachers thought that lower teacher-child ratios within a mixed-age classroom was desirable.

• 대한치과교정학회지
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• 제44권1호
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• pp.13-19
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• 2014

Objective: The aim of this study was to evaluate long-term changes in the pharyngeal airway dimensions after functional appliance treatment in adolescents with skeletal Class II malocclusions. Methods: Pharyngeal airway dimensions were compared between subjects with skeletal Class II malocclusions (n = 24; mean age: $11.6{\pm}1.29$ years) treated with a Class II bionator and age-matched control subjects with skeletal Class I occlusions (n = 24; mean age: $11.0{\pm}1.21$ years) using a series of lateral cephalograms obtained at the initial visit (T0), after treatment (T1), and at the completion of growth (T2). Results: The length of the nasopharyngeal region was similar between adolescents with skeletal Class I and Class II malocclusions at all time points, while the lengths of the upper and lower oropharyngeal regions and the pharyngeal airway areas were significantly smaller in the skeletal Class II adolescents before treatment when compared to the control adolescents (p < 0.05). However, following treatment with a functional appliance, the skeletal Class II adolescents had increased pharyngeal airway dimensions, which became similar to those of the control subjects. Conclusions: Functional appliance therapy can increase the pharyngeal airway dimensions in growing adolescents with skeletal Class II malocclusions, and this effect is maintained until the completion of growth.

• International Journal of Reliability and Applications
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• 제3권1호
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• pp.17-23
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• 2002

The class of “new better than used of a specified age” is a large and practical class of life distributions. Its properties, applicability, and testing was discussed by Hollander, Park and Proschan (1986). Their test, while remaining the yardstick for this class, suffers from weak efficiency and weak power, especially for specified ages below the average age. Thus, it is beneficial to have an alternative testing procedure that would work better for early ages and still work well for later ages. This is exactly the subject of the current note. The test developed here is also simpler than that of Hollander, et. al. (1986).

• 대한치과교정학회지
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• 제47권4호
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• pp.248-255
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• 2017

Objective: The purpose of this study was to investigate whether the craniofacial patterns of Korean children with snoring and adenotonsillar hypertrophy (ATH) could be categorized into characteristic clusters according to age. Methods: We enrolled 236 children with snoring and ATH (age range, 5-12 years) in this study. They were subdivided into four age groups: 5-6, 7-8, 9-10, and 11-12 years. Based on cephalometric analysis, the sagittal and vertical skeletal patterns of each individual were divided into Class I, II, and III, as well as the normodivergent, hypodivergent, and hyperdivergent patterns, respectively. Cluster analysis was performed using cephalometric principal components in addition to the age factor. Results: Three heterogeneous clusters of craniofacial patterns were obtained in relation to age: cluster 1 (41.9%) included patients aged 5-8 years with a skeletal Class I or mild Class II and hyperdivergent pattern; cluster 2 (45.3%) included patients aged 9-12 years with a Class II and hyperdivergent pattern; and cluster 3 (12.8%) included patients aged 7-8 years with a Class III and hyperdivergent pattern. Conclusions: This study found that the craniofacial patterns of Korean children with snoring and ATH could be categorized into three characteristic clusters according to age groups. Although no significantly dominant sagittal skeletal discrepancy was observed, hyperdivergent vertical discrepancy was consistently evident in all clusters.

• 한국산학기술학회논문지
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• 제19권6호
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• pp.324-333
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• 2018

본 연구의 목적은 만성질환인 고혈압, 이상지질혈증, 관절염, 갑상선 질환, 우울증, 아토피, 알레르기, 당뇨병 등의 잠재계층이 어떻게 구성되어 있는지와 유형화된 만성질환의 예측요인을 살펴보고자 하는 것이다. 연구대상은 2014년 국민건강영양조사에 참여한 대한민국 국민으로, 표본추출방법은 층화집락표본추출방법을 사용하였으며 표본 수는 총 7,550명이고, 이를 대상으로 잠재계층분석을 적용하였다. 결과적으로 1 class 유형은 고혈압, 당뇨 그룹으로 고혈압을 앓고 있을 확률이 78.6%이고 당뇨병을 앓고 있을 확률이 34.6%이었다. 2 class 유형은 아토피, 알레르기 그룹으로 아토피를 앓고 있을 확률이 20.3%이고 알레르기를 앓고 있을 확률이 42.2%이었다. 3 class 유형은 이상지질, 관절염, 갑상선질환, 우울증 그룹으로 이상지질 56.1%, 관절염 50.9%, 갑상선 질환 19.4%, 우울증 28.75%로 나타날 확률을 지닌 집단이었다. 4 class 유형은 만성질환을 갖고 있지 않은 정상집단으로 나타났다. 준거변수인 4 class와 1 class를 비교하였을 때, 연령, 운동능력, 자기관리, 비만, 고콜레스테롤 유병여부 등이 유의하게 나타났고, 2 class와 비교하였을 때, 성별, 연령, 교육수준 등이 유의하게 나타났으며, 3 class와 비교하였을 때, 성별, 연령, 통증 및 불편, 고 콜레스테롤 등이 유의하게 나타났다. 결과적으로 세 유형 모두 연령은 복합적인 만성질환을 일으킬 수 있는 요인으로 나타났는데, 이는 질환을 일으킬 수 있는 결정적인 시기가 오기 전에 예방이 중요하다는 것을 의미한다. 따라서 연령에 따른 질병의 유병율 발생 시기를 파악하여 이에 적절한 예방적 노력이 필요하다.

• International Journal of Reliability and Applications
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• 제16권1호
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• pp.27-34
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• 2015

Based on increasing concave ordering a new class of life distribution is introduced. The new class of life distribution is named used better than aged in increasing concave ordering and is denoted by UBAC(2). The implication of our proposed class of life distribution with other classes is given. The properties of UBAC(2) under convolution, discrete mixture and formation of a coherent system are studied. Finally a characterization of the proposed class of life distributions by Laplace transform is discussed.

• 대한치과의사협회지
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• 제19권12호통권151호
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• pp.1027-1030
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• 1981

2065 patients who visited orthodontic department form 1977. 7. 16. to 1981. 9. 30. were surveyed on the yearly tendency of patient distribution and the state of Angle's Classification. The results were as follows: 1. There was increased visiting rate of patient per year except the year 1980. 2. 8-13 age group was 55% in total visiting patient and 20 age over group was 11.0%. 3. Class I malocclusion was 42.3% in total visiting patient, more Class III malocclusion was prevalent than Class II malocclusion.

• 한국산림과학회지
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• 제12권1호
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• pp.13-21
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• 1971

잣나무삼림(森林) 영급계별(令級階別)로 구분(區分)하고, 하층식생(下層植生)을 관대층(灌大層)과 관대층하(灌大層下)의 임상식물층(林床植物層)으로 구분(區分), 영급(令級)에 따른 이들의 종류조성(種類組成)을 조사(調査), 우점종(優占種)을 식별(識別)하고 구성종(構成種)의 현존량(現存量)을 측정(測定), 구성종(構成種)과 현존량(現存量)의 천이계열(遷移系列)에 있어서의 변화관계(變化關係)를 검토(檢討)했다. 1). 잣나무임하(林下)의 중요관대종(重要灌大種)은 Corylus heterophylla var. japonica이며 영급계별(令級階別) 식재림(植栽林)의 관대(灌大)의 우점종(優占種)은 아래와 같다. 5년생급계(年生級階) ; Quercus mongolica, Lespedeza Maximowiczi. 15년생급계(年生級階) ; Corylus heterophylla var. japonica, Lespedeza Maximowiczi. 25년생급계(年生級階) ; Corylus heterophylla var. japonica, Weigla subsesilis. 35년생급계(年生級階) ; Corylus heterophylla var. japonica, Maackia amurensis. 40년생급계(年生級階) ; Corylus heterophylla var. japonica, Morus bombcis. 2). 관대(灌大)의 높이 및 밀도(密度)는 주임목(主林木)의 영급상승(令級上昇)에 따라 감소(減少)한다. 3). 관대하(灌大下)의 임상식물(林床植物)의 우점종(優占種) 주임목(主林木)의 영급(令級)에 따라 아래와 같다. 5년생급계(年生級階) ; Arundinella hirta var. cilia, Miscanthus purpurascens. 15년생급계(年生級階) ; Arundinella hirta var. ciliata, Potentilla Freyniana. 25년생급계(年生級階) ; Physematium manchuriense, Viola xanthopetala, Rubus craegifolius, Polygonatum japonicum, Aster scaber. 35년생급계(年生級階) ; Rubus crataegifolius, Vicia unijuga var. typica. 40년생급계(年生級階) ; Rubus crataegifolius, Dioscorea japonica, Viola xanthopetala. 4). 관대하(灌大下)의 임상식물(林床植物)의 현존량(現存量)은 천이계열(遷移系列)에 있어서 잣나무림(林)의 영급상승(令級上昇)에 따라 감소(減少)되고 있으며 이는 임상식물(林床植物)의 높이, 밀도(密度)의 감소(減少)에 동등(同等)히 영향(影響)을 받고 있으며 식생종류조성(植生種類組成)의 변화(變化)에도 원인(原因)한다. 5). 관대하(灌大下)의 임상식물(林床植物)의 지하부대지상부(地下部對地上部)의 현존량(現存量)의 비율(比率)은 임령(林令)의 상승(上昇)에 따라 증가(增加)하고 있다. 6). 관대하(灌大下)의 종류조성(種類組成)은 천이계열(遷移系列)에 있어서 잣나무림(林)의 영급상승(令級上昇)에 따라 양지성식물(陽地性植物)로부터 음지성식물(陰地性植物)로 변(變)해 가고 있다.