• Title/Summary/Keyword: age class

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Ecological Studies on Several Forest Communities in Kwangnung. A Study of the Site Index and the ground vegetation of Larch (광릉삼림의 생태학적 연구 낙엽송의 Site Index와 임상식생에 관하여)

  • 차종환
    • Journal of Plant Biology
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    • v.9 no.1_2
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    • pp.7-16
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    • 1966
  • In order to determine the factors related to site quality, 13 areas of Larch growing in the Kwangung and its vicinity forest as sample plots, were examined. Sample plots included various site classes as well as age classes. Three were divided into two groups (major and minor trees). Average height of dominant trees was determined through messurement of 5 to 6 dominant tree in each sample plots. Average height of dominant 30 year-old trees was the basis for site index. A Standard Yield Table for the larch produced in Kwangnung forest was made by various data, which included age class 5, ranging from 10 to 45 years. The relationship of the height of the trees, the site conditions, and ground vegetation are investigated in this paper. The site indexes of 40 forest class age in 28-B and 28-G forest classes of the larch associations for ground vegetation had comparatively rarge differences due to the sampled areas. The relation of the direction of forest communities to the height and the diameter of the tree shwoed that its communiteis of northest and northwest parts appeared higher valueof the height and the diameter. The diameter and the height of trees were closely realted to each other. The samller the occupied area per tree and the smaller the average distance among trees, the more density was increased. The larger the density was the lower height of the trees. In the ground vegetation of the larch communities, there seems to be a definite correlation between the height of trees and the occupied area per tree or the average distance among the trees. The height of trees and site index of two larch communities were as follow: 28-B forest class site index 20.8, height 24.0m, 28-G forest class site index 18.4, height 20.9m. The ground layer was analyzed by the method of Quadrat(20/20sq. cm) with an interval of 1M. It set up 40 Quadrats of the larch communiteis. The community structure of the ground vegetation of two larch was analyzed, and important value was calculated and then evaluated. The ground vegetation under the larch had developed Burmannii Beauv stratal society below the 28-B and 28-G the forest class. Accordingly, the first important value of Burmannii Beauv was found in two ground vegetation below the larch. Therefore, this species could be quantitatively considered as the forest indicator species. Common species of each community appeared 18 species out of 34 species in the ground vegetation under two larch communities. The ground vegetation of the 28-B forest class showed more than that of the 28-G forest class. the similarity of the ground vegetation was measrued by the Frequency Index Community Coefficient. The differences between the associations were lcearly manifested by the ground vegetation tested by Gleason's Frequency Index of Community Coefficient for the analysis of each stratal society of all associations. According to F.I.C.C. the ground vegetation under two larch(28-B and 28-G) forest classes showed higher value. An investigation into the relationship of physical and chemical properties of soil and site was considered the next step to be taken in the study of the larch site classification.

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Impacts of Mt. Bongeui on Atmospheric Purification in Chuncheon

  • Piao, Zhi Hui;Jo, Hyun-Kil
    • Journal of Forest and Environmental Science
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    • v.34 no.2
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    • pp.165-168
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    • 2018
  • Mt. Bongeui is a neighborhood park of 66.4 ha as a major natural landscape resource located in the center of Chuncheon City. This study quantified the reduction of carbon, $SO_2$, $NO_2$, $O_3$, and $PM_{2.5}$, and the production of $O_2$ to explore the role for Mt. Bongeui to contribute to annual atmospheric purification. The main forest types and age classes of the study site included age-class III broadleaved forest at 35.8%, age-class VI coniferous forest at 17.2%, and age-class IV broadleaved forest at 15.7%. The annual atmospheric purification effect per unit area was as follows: 7.6 t carbon/ha/yr, 16.6 kg $SO_2/ha/yr$, 40.4 kg $NO_2/ha/yr$, 41.5 kg $O_3/ha/yr$, 53.7 kg $PM_{2.5}/ha/yr$, and 20.2 t $O_2/ha/yr$. The economic value of these effects was equivalent to about 12.9 million KRW/ha/yr. The study site annually offset carbon emissions of about 300 citizens, $SO_2$ emissions of 220 citizens, and $NO_2$ emissions of 92 citizens in Chuncheon. It also played an important role in annually producing 1.5% of the amount of $O_2$ necessary for the respiration of Chuncheon's total population. This study pioneers in comprehensively quantifying the atmospheric purification effect and could be useful in guiding the planning and management to improve the effect.

Longitudinal Trajectories of Computer Game Use among School Age Children: Using Latent Class Growth Model (학령기 아동의 게임 사용시간 변화궤적 분석 : 잠재계층성장분석(LCGM)을 활용하여)

  • Kim, Dong Ha
    • Korean Journal of Social Welfare Studies
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    • v.48 no.2
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    • pp.303-329
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    • 2017
  • This study aimed to explore the trajectories of computer game use of school age children and to identify the related predictors. The data for this study used Korean Children and Youth Panel data covering from the second year to the sixth year of elementary school. A total of 1,959 participants were analyzed. Latent class growth model was employed to explore the trajectories of computer game use and multinomial logistic regression was conducted to identify the significant predictors. Main results indicated that three types of trajectories were identified: low game using group, high initial using-fluctuating group, and high increasing game using group. Each group was found to be associated deferentially with sex, aggression, attention deficit, main caregiver's education, siblings, parent absence after-school, neglecting, family income, family trip, school grades, and peer relationship. Based on these findings, this study emphasized the importance of predictive intervention for the game user among early school age children and suggested useful practical strategies.

Factors Influencing Upper Airway Dimensions in Skeletal Class II Children and Adolescents: A CBCT Study (골격성 II급 소아·청소년의 상기도 공간에 영향을 미치는 요인 : CBCT 연구)

  • Kim, Byounghwa;Lee, Jewoo;Ra, Jiyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.48 no.1
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    • pp.1-11
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    • 2021
  • The purpose of this study is to investigate factors influencing the upper airway dimensions in skeletal Class II children and adolescents. In total, 67 patients were selected. Airway volume and minimal cross-sectional area were three-dimensionally assessed. Craniofacial morphology and skeletal maturity were assessed on generated two-dimensional cephalograms. The measurements were analyzed using Mann-Whitney test, one-way ANOVA, Pearson's correlation, and multiple regression analysis. Upper airway dimensions were significantly smaller in pre-peak stage group, and positively associated with age. Anterior facial height and age were the most relevant factors for airway volume. Mandibular width and age were the most relevant factors for minimal cross-sectional area. Upper airway dimensions were significantly associated with age, skeletal maturity and craniofacial morphology in all three planes.

A Study of Chronic Constrictive Pericarditis (만성 수축성 심낭염의 임상적 고찰)

  • 김현경
    • Journal of Chest Surgery
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    • v.24 no.10
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    • pp.973-978
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    • 1991
  • From January, 1982, to December, 1990, 15 patients underwent pericardiectomy for chronic constrictive pericarditis on Department Of Thoracic and Cardiovascular Surgery, School of Medicine, Pusan National University. There were 9 male and 6 female patients [male to female ratio was 1.5: 1] ranging from 15 years to 63 years old [mean age 35.0]. All patients underwent pericardiectomy through a median sternotomy, partial cardiopulmonary bypass was performed on two patients. There were 3 postoperative death [20%]. Six cases [40%] were tuberculous origin 5 cases [34%] were Idiopathic [nonspecific chronic inflammatory change was considered to idiopathic], 2 cases [13%] were malignant origin, 2 cases [13Yo] were pyogenic origin. Dyspnea on exertion was evident in all patients and abdominal distention, general weakness, palpitation, peripheral edema were found. Eleven patients showed low voltage of QRS wave, 7 patients showed diffuse ST-T wave change, 2 patients showed atrial fibrillation on EKG. There were 6 patient showed pericardial thickening, 5 patients showed evidence of restriction, 5 patients showed pericardial effusion, 4 patients showed low cardiac output on preoperative echocardiogram. Hemodynamic response to pericardiectomy were observed; preoperative CVP 26.8 cmH2O declined to 15.0 cmH2O. Preoperative NYHA Functional class showed class II - 1, class III - 10, class IV - 4, postoperative NYHA functional class showed class I - 7, class II - 4, class Ill - l.

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A ROENTGENOCEPHALOMETRIC STUDY ON THE SOFT TISSUE OF THE CHILDREN IN MIXED DENTITION (측모 두부방사선 계측법에 의한 혼합 치열기 아동의 연조직에 관한 연구)

  • Kim, Sun-Hae;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
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    • v.15 no.2
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    • pp.229-237
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    • 1985
  • The Purpose of this study was to investigate the differences in soft tissue characteristics according to the dental or skeletal dysplasia. For this purpose, lateral cephalogram of 153 children (Hellman dental age IIIB: control group 32, Angle CIII. div. 1 malocclusion group 55, Angle Cl III group 66) were traced and measured. For these measurements, following conclusions were made. 1. FH A, FH Sn, FH UL, AA' of the Class III group were thicker than those of the normal and Class II group, but FH B, FH LL, BB' of the Class III group were not significantly different from those of the normal group. 2. FH B, FH LL, BB' of the Class II group were thicker than those of the normal and Class III group, but FH A, FH Sn, FH UL, AA' of the Class II group were not significantly different from those of the noraml group. 3. Ans-Sn, FH P were not significantly different in three groups, while PP' of the Class III group was thicker than those of the other groups. 4. The lower lips of the Class II group were more anterioly everted with respect to the lower incisor inclination than those of the other groups. 5. The severity of skeletal dysplasia was partly camouflaged by the soft tissue.

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Health related behavior patterns and associated factors among marriage immigrant women using latent class analysis (잠재계층분석을 활용한 결혼이주여성의 건강관련행동 군집유형과 영향요인)

  • Cho, Wonsup;Yoo, Seunghyun;Kim, Hyekyeong
    • Korean Journal of Health Education and Promotion
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    • v.32 no.5
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    • pp.17-31
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    • 2015
  • Objectives: This paper aims to identify the health related behaviors patterns and its associated factors among marriage immigrant women in Korea, and discusses their application to health promotion strategies. Methods: The study participants were 7,591 immigrant wives in Gyeonggi province who participated in health examinations conducted by the Korea Association of Health Promotion in 2011-2013. The participants completed self-administered questionnaires on sociodemographics, psychological characteristics, health status and health care factors, and health related behaviors. Results: A 3-latent-class model of health behaviors was identified related to 'lack of physical activity', 'abnormal diet', and 'not experienced medical check-up': 'high risk class', 'middle risk class', and 'low risk class'. Most of the participants belong to 'middle risk class'. Country of origin, age, length of stay, number of children, work status, health insurance status, and unmet health care needs were associated with problematic health behaviors in middle risk health behavior class. Conclusions: Health promotion and intervention programs for marriage immigrant women and their family members need to consider the health behavior patterns of physical inactivity, abnormal diet and no medical check-up and develop multiple behavior intervention with pre-existing program modification.

Social Class in Modern Film Costumes -Focused on Bong Joon-Ho's - (영화 의상에 나타난 사회 계급의 표현 -봉준호 감독의 <기생충>을 중심으로-)

  • Choi, Yeong-Hyeon;Lee, Kyu-Hye
    • Journal of the Korean Society of Clothing and Textiles
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    • v.44 no.5
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    • pp.856-877
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    • 2020
  • This study examines how class differences are expressed through costumes based on the costumes of characters in Bong Joon-Ho's film . Based on Video on Demand (VOD), the main situations in which characters' costumes change in the play were captured and used as analysis data. Colors, textures, and color symbol were analyzed to find the formative properties shown in the characters' costumes. The results are as follows. The home wear of Kim's family were unsuitable for the top and bottom, faded clothes, and the vague boundary between outdoor and indoor clothes appeared. In comparison, Park's family's home wear was featured a modern and elegant design, a clear distinction that suited purpose and situation. Analysis of street wear showed that the Kim's family had a big difference before and after getting a job, and Park's family wore different costumes for the purpose of going out. Social class expressed in the film costumes were shown to have the characteristics of intrinsic class invariance, temporary class changes, differences in class expression by age, and differences in costume choice by class.

Dentoalveolar Characteristics according to facial types of Class III Malocclusion (골격성 III급 부정교합의 골격유형에 따른 치아치조특성)

  • Park, Song-Soo;Kim, Hyun-Deog;Lee, Dae-Hee;Kim, Jong-Ghee;Jeon, Young-Mi
    • The korean journal of orthodontics
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    • v.32 no.1 s.90
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    • pp.33-42
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    • 2002
  • This study was performed to compare the pattern of dentoalveolar characteristics in different vertical and anteroposterior skeletal types in skeletal Class III malocclusion. The samples selected for this study were consisted of 60 subjects(29 males and 31 females, mean age; 19.7 years) in Class III group, 43 subjects(14males and 29 females, mean age : 20.5 years) in normal group. The findings of this study were as follows : 1. The IMPA of the Class III group was smaller than that of the Class I group(p<0.01). 2. In the Class III groups, SNB and NtoPog had negative correlation with IMPA(p<0.01). The SNB and NtoPog had correlations with SNU1, FHU1 and PalU1(p<0.01) in the male samples, and in the female samples, the SNB and NtoPog had correlations with SNU1(p<0.01). 3. In the Class III male samples, SNMP, FMA, PalMP had negative correlation with IMPA(p<0.01). SNMP, FMA, PalMP had not significant correlation with SNU1, FHU1, PalU1. In the Class III female samples, FMA, PalMP had negative correlation with IMPA(p<0.01). 4. In the high angle group of Class III samples, SNU1, IMPA is smaller than that of low angle group of Class III samples(p<0.05).

THE VARIATION OF MANDIBULAR PATTERN AND CRANIAL BASE ANGLE IN CRANIOFACIAL MALOCCLUSION (부정교합의 유형에 따른 두개저와 하악골의 형태에 환한 연구)

  • Kwon, Ki-Youl;Lee, Ki-Soo;Chung, Kyu-Rim
    • The korean journal of orthodontics
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    • v.16 no.1
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    • pp.107-118
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    • 1986
  • This study was designed to investigate the variation of mandibular pattern and cranial base and their association in the craniofacial malocclusion. The material was the 165 cephalometric radiographs taken from craniofacial malocclusion. The sample was devided into two groups by age child group aged from 10 to 13 years and adult group aged over 18 years, and each group was devided into 3 types of malocclusion; class I, Class II div. 1 and Class III malocclusion. Child group consist of 35 samples and adult group consist of 20 samples in each malocclusion type. Various angular and linear measurements on the cephalometric radiographs were recorded and statistically analyzed. The results of the study were as follows; 1. The cranial base angle was largest in Class II div. 1 malocclusion and smallest in Class III malocclusion 2. The anterior cranial base length was largest in Class II div. 1 malocclusion but posterior cranial base length did not show statistical difference. 3. The mandibular body length of Class III malocclusion was larger than those of Class I and Class II div. 1 malocclusion in the adult group but did not shown difference in the child group. The ramus height of Class III malocclusion was larger than those of Class I and Class II div. 1 malocclusion in the child and adult group, but there were no difference between Class I and Class II div. 1 malocclusion. 4. The mandibular position was showed low correlation with the cranial base angele.

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