• Title/Summary/Keyword: Longitudinal Data

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Study on the shrinkage properties of commercial hardwoods (유용(有用) 활엽수재(闊葉樹材)의 수축(收縮)에 관(關)한 연구(硏究))

  • Kim, Young-Suk;Lee, Won-Yong
    • Journal of the Korean Wood Science and Technology
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    • v.4 no.1
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    • pp.8-14
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    • 1976
  • The capacity of wood to shrinkage is very important as the basis data for wood industry but there is no such data available as yet in Korea. So this article, as a study on forest biological, were made to determine the shrinkage properties of commercial hardwoods in Korea. The results of this study were as follows; 1) There are much difference of hardwoods shrinkage, generally values of heavy wood's shrinkage were larger than that of light wood's shrinkage. 2) The arithmetic; mean values of hardwoods shrinkage were respectively 9.03% on tangential, 4.09% on radial and 0.37% on longitudinal direction and its ratio of at : ar : al was appeared to be 10 : 5.5 : 0.4 3) Average shrinkage per 1% of moisture content was different due to the direction and species. 4) According to the increase of specific gravity the values of shrinkage increased. 5) It was recognized that the shrinkage of hardwoods had a tendency to decrease as increase of annual ring width of wood. 6) The shrinkage of tangential direction was in propertion to the shrinkage of radial direction.

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A Study of Factors Effecting on Gifted Students' Achievement : Self-determination, Learning Goal-orientation, Self-efficacy, Implicit Theory of Intelligence, and Self-regulated Learning Strategy (영재의 학업성취에 영향을 주는 심리적 요인들: 자기결정성, 학습목표지향성, 자기효능감, 지능관 및 자기조절학습전략을 중심으로)

  • Jo, Son-Mi
    • Journal of Gifted/Talented Education
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    • v.21 no.3
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    • pp.611-630
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    • 2011
  • The purpose of the study was to investigate which psychological factors influence on the gifted students' achievement. As a psychological factor, self-determination, learning goal-orientation, self-efficacy, belief of intelligence, and self-regulated learning strategy were examined. The difference in psychological factors between the gifted with high achievement and the gifted with low achievement was to explored. For the study 128 gifted students' data from second-year data of Korean Education Longitudinal Study (KELS) were selected and analyzed. The findings indicate that the predictors of gifted students' achievement are extrinsic regulation, identified regulation, mastery-approach goal, self-efficacy, elaboration, and meta-cognition factor. Especially, the factor of elaboration and identified regulation are the strongest predictors. The findings from t-test analysis indicate that the gifted with low achievement show the low level in self-determination, mastery-approach, self-efficacy, elaboration, meta-cognition, place management and seeking social assistance from teacher. Therefore the developing elaboration, one of regulation learning strategy, is essential to improve the achievement of the gifted students with low scores.

Concentrations of PBDE Congeners in Breast Milk and Predictors of Exposure in Seoul Residents (서울 거주 산모 모유 중 PBDEs 이성질체 농도 및 노출 요인에 관한 연구)

  • We, Sung-Ug;Yoon, Cho-Hee;Min, Byung-Yoon
    • Journal of Environmental Health Sciences
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    • v.37 no.6
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    • pp.440-449
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    • 2011
  • Objectives: This study was designed to determine the levels of polybrominated diphenyl ethers (PBDEs) in breast milk and to evaluate the relations with factors affecting these levels. Methods: The congener levels of PBDE in 22 samples of breast milk were analyzed using a high resolution gas chromatograph with a high resolution mass detector. In accordance with our standard operating procedures, the recoveries of internal standards had to range between 68% and 118%. Since the distribution of PBDE concentrations is close to log-normal, the data were logarithmically transformed before analysis. Test subjects were healthy primipara and multipara mothers with a mean age of 32 (SD = 2.7) in 2006. Results: Seven PBDE congeners (BDE-28, 47, 99, 100, 153, 154, and 183) were detected and identified in all of the pooled breast milk samples, indicating widespread contamination from PBDEs in the environment in Korea. Residue levels of total PBDEs (sum PBDEs from tri- to hepta-BDE) ranged from 0.84-13.1 ng/g lipid with median and geometric mean levels of 2.6 ng/g lipid and 2.74 ng/g lipid, respectively. PBDE congeners 47, 99 and 153 markedly predominated and accounted for about 75% of the amount of the PBDE congeners analyzed. BDE-47 was the dominant congener in most samples, whereas BDE-153 was predominant in a few (n = 7/22). BDE-47 was highly correlated with total PBDEs (r = 0.987, p < 0.01). In analyses of the differences of the means of log transformed breast milk PBDE levels for groups of potential covariates, only breast milk BDE-47 and BDE-99 levels were significantly associated with fish (p < 0.05) and meat consumption (p < 0.01). However, we did not find significant correlations between PBDE levels and maternal age, body mass index (BMI), parity, job presence and smoking status. Conclusions: Our findings are mainly limited due to the small sampling size and low doses of PBDEs exposure. Background and human exposure data of PBDEs is lacking, and longitudinal investigations into the environment and biota are encouraged to determine the health impact on future populations in Korea.

Factors Influencing on Health Promoting Behavior of Community-dwelling Older Adults (지역사회 거주 노인의 건강증진행위에 영향을 미치는 요인)

  • Jang, Ji-Hye;Shin, Yong Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.460-469
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    • 2020
  • The purpose of this study was to examine the predictive factors for health promotion behaviors of older adults in rural areas. A theoretical substruction was constructed to test hypothetical models based on Pender's health promotion model. The data was collected from 199 older adults aged 65 years or older, who resided in G city, by using a structured questionnaire. The questionnaires contained items on individual characteristics, health literacy, self efficacy and health promoting behavior. The data was analyzed with a t-test, ANOVA, Pearson's correlation coefficients and hierarchical multiple regression analysis using SPSS 20.0 for Windows. The predictive factors for the health promotion behavior were the number of health information channels (β=.16, p=.031) and self efficacy (β=.53, p<.001). The total explanatory power of these factors was 30.8%. A nursing intervention plan for improving health promoting behaviors of older adults should be developed and applied, with a focus on self-efficacy and health information channels. Further longitudinal studies are needed to help confirm relevant measurement of the level of health promoting behaviors of older adults.

Integrated analysis and design of composite beams with flexible shear connectors under sagging and hogging moments

  • Wang, A.J.;Chung, K.F.
    • Steel and Composite Structures
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    • v.6 no.6
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    • pp.459-477
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    • 2006
  • A theoretical research project is undertaken to develop integrated analysis and design tools for long span composite beams in modern high-rise buildings, and it aims to develop non-linear finite element models for practical design of composite beams. As the first paper in the series, this paper presents the development study as well as the calibration exercise of the proposed finite element models for simply supported composite beams. Other practical issues such as continuous composite beams, the provision of web openings for passage of building services, the partial continuity offered by the connections to columns as well as the behaviour of both unprotected and protected composite beams under fires will be reported separately. In this paper, details of the finite elements and the material models for both steel and reinforced concrete are first described, and finite element studies of composite beams with full details of test data are then presented. It should be noted that in the proposed finite element models, both steel beams and concrete slabs are modelled with two dimensional plane stress elements whose widths are assigned to be equal to the widths of concrete flanges, and the flange widths and the web thicknesses of steel beams as appropriate. Moreover, each shear connector is modelled with one horizontal spring and one vertical spring to simulate its longitudinal shear and pull-out actions based on measured load-slippage curves of push-out tests of shear connectors. The numerical results are then carefully analyzed and compared with the corresponding test results in terms of load mid-span deflection curves as well as load end-slippage curves. Other deformation characteristics of the composite beams such as stress and strain distributions across the composite cross-sections as well as distributions of shear forces and slippages in shear connectors along the beam spans are also examined in details. It is shown that the numerical results of the composite beams compare well with the test data in terms of various load-deformation characteristics along the entire deformation ranges. Hence, the proposed analysis and design tools are considered to be simple and yet effective for composite beams with practical geometrical dimensions and arrangements. Structural engineers are strongly encouraged to employ the models in their practical work to exploit the full advantages offered by composite construction.

The Relationship Between Bone mineral Density and The Environmental Factors in Korean Pubescent Girls (한국 사춘기 소녀들의 골밀도와 환경요인들과의 관계(II))

  • 최미자
    • Journal of the East Asian Society of Dietary Life
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    • v.5 no.1
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    • pp.41-51
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    • 1995
  • Bone mass accretion during puberty appears to be critical in the development of peak bone mass. Although bone density of females in Korea has been studied, only a few studies have related bone mass with anthropometric patterns or puberty in the pubescent girls. This study was conducted as part of a study of major determinants of bone development during puberty. Subjects were aged 14∼16 yr(mean 14.97), and had no history of disorders or dedication use likely to influence bone or calcium metabolism. Bone mineral density and content were measured by dual energy X-ray absorptiometry using a Lunar DPX+Scanner (Lunar Madison, WI). Also, total body fat, and total lean body mass were assessed using a Lunar DPX dual-energy X-ray absorptiometer, Pubertal status was assessed according to the Marshall and Tanner guidelines. Serum levels of osteocalcin was measured by RIA using a commercial kit assay. Skinfold measurements were taken with a skinfold caliper(Lange Caliper, USA). Data were analyzed using the regression and GLM procedure of the statistical package SAS. The results indicated that the observed means for lumbar spine BMD and femoral BMD correspond to approximately 91% and 96% of the means for young adult females, respec tively. All subjects were menarchal, with the majority being in the middle to end stages of pubertal development. Total body BMD was positively related to fat mass(P<0.001), lean body mass and time since menarche, and negatively related to urine pyridinoline, serum alkaline phosphatase and osteocalcin. The data indicate that girls who reported lower age for menarche had significantly higher bone densities than girls who reported higher age for menarche. Attaining peak skeletal bone mass during puberty may reduce the incidence of osteoporosis in later life. this finding suggests that early menarche may augment peak bone mass, influencing the extent of bone loss later in adulthood. The results suggest that good nutrition in childhood appears to be needed not for growth and development, but possibly also to assure an optimal peak of bone mass and thus greater latitude for the maintenance or skeletal integrity in the face of bone losses. Troeps skinfold thickness was a better predictor of total BMD and total BMC than was any other skinfold thickness. The study did not find a relationship between total BMD and body fat %, but total fat was significantly positively related to total BMD(r=0.49) and total BMC(r=0.60). It supports earlier report that there was a significant correlation between TBMD and body weight. Conclusively, total fat, lean body mass and pubertal development could influence BMD in pubescent girls. Clearly, longitudinal studies are required to assess the effect of puberty on peak bone mass, and to define further the potential determinants of peak bone mass.

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Decisional balance corresponding to the Stage of Change of Smoking Cessation in Middle Aged Men (중년 흡연남성의 금연 변화단계에 따른 의사결정 균형에 대한 연구)

  • Chang Sung-Ok;Park Chang-Seung;Min In-Sun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.2
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    • pp.164-176
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    • 2000
  • Purpose : This study was done to identify the factors of decisional balance for smoking cessation among middle aged men in Korea. This was composed of a set of variables at the level of decision making when middle aged men decide to stop smoking. It was used to classify and identify the characteristics of the stages of change for smoking cessation to which the middle aged men belong, and was used to identify the variables of decisional balance which influenced the stages of change for smoking cessation in middle aged men. Methods : A convenience sample of 169 men who had smoked and were smoking, were between age 30 and 60 and lived in Seoul(mean age=44), were selected from the community. The data was collected from December 10, 1999 to February 28, 2000. The research instrument was the Decisional Balance Measure for Smoking Cessation (Velicer et al., 1985). and Stage of Change Measure(DiClemente et al., 1991). The data were analyzed using the SAS Program. Results : 1. According to stage of change measure, the 169 subjects were distributed in each stage of change for smoking cessation: in the pre-contemplation stage 63 subjects(32.7%), contemplation stage 60 subjects (35.5%), preparation stage 17 subjects(10.1%), and maintenance stage 29 subjects(17.2%). 2. Factor analysis identified 4 factors of decisional balance as appropriate factors for smoking cessation of middle aged men. There were named by the researchers; 1)'Perceived Burden to Self', 2)'Perceived Benefit to Others' 3)'Perceived Approval to Others', and 4)'Perceived Disapproval to Self'. 3. Analysis of variance showed that the three components, 1)'Perceived Burden to Self(F=8.50, P=.0001)', 2)'Perceived Benefit to Others(F=3.19, P=.025)' and 3)'Perceived DisApproval to Self(F=2.87, P=.038)were significantly associated with stage of change. 4. Through discriminant analysis, it was found that 'Perceived Burden to self' was the most influential variable in discriminating the four stages of change(pre-contemplation, contemplation, preparation, and maintenance). Conclusion : The results are consistent with the application of the Transtheoretical model, which has been used to understand how people change health behavior. Even though this study is a cross-sectional, not a longitudinal study, the findings of this study give useful information for smoking cessation intervention for the middle aged men.

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A Study on the Change of Primipara's Mother - Infant Interactional process (모아상호작용과정의 진행양상에 관한 연구)

  • Cho, Mi-Young
    • Women's Health Nursing
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    • v.1 no.1
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    • pp.5-27
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    • 1995
  • One of the important tasks for new parents, especially mothers, is to establish warm, mutually affirming interpersonal relationships with the new baby in the family, with the purpose of promoting the health development of the child and the well-being of the whole family. Nurses assess the quality of the behavioral characteristics of the maternal-infant interaction. The purpose of this longitudinal descriptive correlational study is to investigate the changes of the mother - infant interactions from postpartum 1 day to postpartum 8weeks of the transition to parenthood. The aim was to contribute to the development of theoretical under standing on which to base care toward promoting the quality of maternal - infant interaction. Data were collect ed directly by the investigator and at rained from Jul, 1, 1990 to Jun 8, 1991, Subjects were a random sample of 44 mothers, 44 who had a normal delivery (but with out other perinatal complications) at four general hospitals in Seoul. Instruments used were the Stainton Parent-infant Interaction Scale (1981). The first observations were made in the delivery room, followed by day 1, day 2, day 3 and 2 weeks, 4 weeks, 6 weeks and 8 weeks after, birth, for a total of 8 contacts. Observations in the hospital were made during the hour prior to scheduled feedings. The infant was placed beside the mother. Later contacts were made at home. Data analysis was don by computer using as SPSS program and included, Paired t-test, t-test and Pearson Correlation coefficient ; the results were as follows. 1. The daily maternal-infant interaction score for the initial contact ofter birth to 8 weeks postpartum had the lowest average score 5.21 and the highest 8.02(in a range of 0-10). This subject group of mothers needed Extra nursing supporting to promote their maternal-infant interaction. 2. The daily scores for the maternal-infant interaction tended to rise, showing a gradual improvement over the period of eight weeks. However, there were significantly different increases in maternal-infant interaction only from the first to second day (p=0.000) and from the fourth to sixth weeks ofter birth.(p=0.000) 3. When the seven items of maternal-infant interaction were evaluated items of maternal-infant inter action were evaluated separately, "Care taking for the baby" had the highest average score, 1.60(in a range of 0-2) and "Speaks to baby" the lowest, 0.8. All items, suggested the subjects' need of nursing intervention to promote maternal-infant interaction 4. There were positive correlations between certain general characteristics, namely, both a higher economic status (p=0.027) and breast feeding (p=0.021) and maternal-infant interaction.

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The Impact Subjective Class Consciousness on Life Satisfaction of the Elderly: A Mediation Effect of Depression (노인의 주관적 계층의식이 삶의 만족에 미치는 영향: 우울 매개효과를 중심으로)

  • Choi, Youn-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.209-218
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    • 2018
  • The purpose of this study was to explore the relationship between the subjective consciousness and life satisfaction of the elderly, and to see how depression affects this relationship. This includes a new way of thinking about the causes of the elderly's life satisfaction, not only for individual factors, but also for subjective class consciousness. For this aim, we examine the degree of subjective class consciousness, life satisfaction and depression of the elderly, and verify mediation effects of depression between subjective class consciousness and life satisfaction. This study utilized data obtained from the 5th version of the Korea Longitudinal Study on Aging 2014, and considered data from 4,222 elderly aged 65 and over. As a means of study, a structural equation model analysis was conducted. The results were as follows: First, it was confirmed that the subjective class consciousness of the elderly may influence life satisfaction. It was also confirmed that the subjective class consciousness of the elderly also affected depression and life satisfaction among the elderly. When subjective class consciousness was high, depression was low and life satisfaction was high. When depression was low, life satisfaction was high. Second, depression had the mediation effect in which subjective class consciousness affects life satisfaction. Based on these results, this author suggests practical and political issues concerning social welfare to prevent and reduce depression and increase life satisfaction through improving the subjective class consciousness of the elderly. First, policy measures should enhance social capital through housing support policies and leisure use support to enhance the subjective class consciousness of the elderly. Second, the provision of services for the elderly through the establishment of a community-based network to reduce depression should be promoted.

The effect of parental neglect, abuse on middle school children's life satisfaction - Focused on the mediating effects of ego-resilience (부모에게 받은 방임과 학대가 중학생의 삶의 만족도에 미치는 영향 -자아탄력성의 매개효과를 중심으로)

  • Woo, Jea-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.569-579
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    • 2017
  • The purpose of this study was to test the mediation effects of adolescents' ego-resilience on the relation between neglect, abuse and life satisfaction. The 6-year longitudinal data from the Korean Children & Youth Panel Survey (KCYPS) were collected from 1st grade middle school students. The data were analyzed by structural equation modeling and Sobel testing.The results of this study were as follows. First, the results revealed that the path from neglect and abuse to life satisfaction was partially mediated by family relations. The relations between trauma(neglect) and ego-resilience are negative(${\beta}=-.258$, p<.001). The relations between ego-resilience and life satisfaction are positive(${\beta}=.843$, p<.001). Second, the verification of the mediation effect of ego-resilience showed that ego-resilience was a full mediator between trauma(neglect) and life satisfaction for 1st grade middle school students(Z=-.169, t(CR)=-.012 (p<.05). Based on these results, the practical implications were discussed.