• Journal of the Korean Wood Science and Technology
• /
• 제4권1호
• /
• pp.8-14
• /
• 1976

본(本) 시험(試驗)은 목재재질(木材材質)의 삼림생물학적(森林生物學的) 연구(硏究)의 일환(一還)으로 목재이용(木材利用) 및 가공(加工)의 기초요인(基礎要因)을 얻기 위(爲)해 유용(有用) 활엽수(闊葉樹) 13재종(材種)에 대(對)하여 방향별(方向別) 수축율(收縮率), 수종별(樹種別) 수축율(收縮率), 함수율(含水率) 1%에 대(對)한 평균(平均) 수축율(收縮率)과의 관계(關係), 연륜폭(年輪幅)과 수축율(收縮率)과의 관계등(關係等)을 비교검토(比較檢討)하였는데 그 결과(結果)를 요약(要約)하면 다음과 같다. 1) 활엽수재(闊葉樹材)의 수축율(收縮率)은 수종(樹種)에 따라 많은 차이(差異)가 있으며 이태리포플러, 양버들의 수축율은 작은 반면(反面) 박달나무, 느릎나무 등(等)의 수축율(收縮率)은 컸다. 2) 절선방향(切線方向), 반경방향(半徑方向) 및 섬유방향(纖維方向)의 수축율(收縮率)은 각각(各各) 9.01%, 4.98%, 0.37%로 공(共)히 절선(切線), 반경(半徑), 섬유방향(纖維方向)의 순(順)으로 작게 나타났으며 그 비율(比率)은 평균(平均) at : ar : al= 10 : 5.52 : 0.41로 나타났다. 3) 함수율(含水率) 1%에 대(對)한 평균수축율(平均收縮率)은 수종(樹種)과 방향(方向)에 따라 많은 차이(差異)가 있다. 4) 비중(比重)과의 관계(關係)에서는 비중(比重)의 증가(增加)에 따라 수축율(收縮率)도 점차 증가(增加)하는 경향(傾向)을 나타내고 있다. 5) 연륜폭(年輪幅)과의 관계(關係)에서는 연륜폭(年輪幅)이 넓어질수록 수축량(收縮量)은 감소(減少)하는 경향(傾向)이 있다. 6) 반경방향(半徑方向)의 수축율(收縮率)이 증가(增加)할수록 절선방향(切線方向)의 수축율(收縮率)도 점차 증가(增加)되고 있다.

• 영재교육연구
• /
• 제21권3호
• /
• pp.611-630
• /
• 2011

본 연구는 영재들의 학업성취에 영향을 주는 심리적 요인인 자기결정성, 학습목표지향성, 자기효능감, 지능관 및 자기조절학습전략의 영향력을 조사하는데 목적이 있다. 또한 영재들 중 학업성취가 높은 학생과 낮은 학생들의 심리적 특성에 차이가 있는지도 살펴보았다. 한국교육종단연구 자료 중 중학교 2학년 영재학생 128명의 자료가 최종 분석되었다. 분석 결과 외적 조절동기는 학업성취에 부적영향을 주는 것으로 나타났고 확인된 조절동기, 숙달접근, 자기효능감, 정교화, 초인지 전략은 정적영향을 주는 것으로 나타났다. 단계적 중다 회귀분석을 통해 학업성취에 영향을 준 6개 하위요인들의 상대적 영향력을 비교하였는데 분석결과 영재들의 학업성취는 정교화에 의해 15.5% 가량이 설명되었고 확인된 조절동기에 의해 추가로 5% 정도 더 설명되었다. 독립표본 t 검정 분석결과 학업성취가 낮은 영재학생들은 자기결정성, 숙달접근성, 자기효능감, 정교화, 초인지, 공간관리, 교사도움에서 낮은 수준을 보였다. 따라서 성적이 낮은 중학교 영재들의 학업문제를 해결하기 위해서는 우선적으로 정교화 인지전략을 발달시킬 필요가 있다.

• 한국환경보건학회지
• /
• 제37권6호
• /
• pp.440-449
• /
• 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.

• 한국산학기술학회논문지
• /
• 제21권2호
• /
• pp.460-469
• /
• 2020

본 연구는 지역사회 거주하는 65세 이상 노인의 건강증진행위에 영향을 미치는 요인을 확인하기 위해 시도되었으며, Pender의 건강증진모형에 근거한 가설적 모형을 검증하기 위해 Theoretical substruction을 구성하였다. 연구대상자는 G시에 거주하는 65세 이상 노인 199명을 대상으로, 구조화된 설문지를 통해 개인적 특성, 건강정보이해능력, 자기효능감 및 건강증진행위를 조사하였다. 자료 분석은 SPSS 20.0프로그램을 이용하여 t-test, ANOVA, 사후검증으로 Scheffé test를 실시하였고, 건강정보이해능력, 자기효능감 및 건강증진행위 간의 관계를 확인하기 위해 Pearson's correlation coefficients로 분석하였으며, 건강증진행위에 영향을 미치는 요인을 확인하기 위해 위계적 회귀분석을 실시하였다. 연구 결과, 노인의 건강증진행위는 4점 기준으로 평균 2.56±0.50점이었으며, 하위영역 중 대인관계 영역이 가장 높았고, 신체활동 영역이 가장 낮았다. 건강증진행위에 영향을 미치는 요인은 건강정보수집 경로의 수(β=.16, p=.031)와 자기효능감(β=.53, p<.001)인 것으로 확인되었으며, 건강증진행위를 30.8% 설명하였다(F=14.19, p<.001). 본 연구 결과를 통해 노인 대상자의 건강증진행위를 높이기 위해서는 개인의 자기효능감 수준과 건강정보의 특성을 고려한 중재가 필요함을 확인하였다. 추후 노인의 건강증진행위 수준과 다양한 영향 요인을 확인하기 위한 지속적인 연구가 필요할 것으로 생각된다.

• Steel and Composite Structures
• /
• 제6권6호
• /
• pp.459-477
• /
• 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.

• 동아시아식생활학회지
• /
• 제5권1호
• /
• pp.41-51
• /
• 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.

• 기본간호학회지
• /
• 제7권2호
• /
• pp.164-176
• /
• 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.

• 여성건강간호학회지
• /
• 제1권1호
• /
• pp.5-27
• /
• 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.

• 한국산학기술학회논문지
• /
• 제19권6호
• /
• pp.209-218
• /
• 2018

본 연구는 노인의 주관적 계층의식과 삶의 만족과의 관계를 알아보고, 이 관계에서 우울이 어떠한 영향을 주고 있는지 살펴보는 것을 목적으로 한다. 이는 노인의 삶의 만족도의 영향요인을 기존의 개인적 차원 요인 뿐 아니라 사회 내에서 개인의 상대적 위치인 주관적 계층의식에 대해 논의해 봄으로써 노인 삶의 만족도에 대한 새로운 관점을 제시하는 의의가 있다고 하겠다. 이를 위하여 노인의 주관적 계층의식, 삶의 만족도, 우울의 정도를 파악하고, 주관적 계층의식과 삶의 만족도의 관계에서 우울의 매개효과를 검증하였다. 본 연구는 2014년 한국고용정보원의 '고령화 연구패널 5차자료'를 활용하여 65세 이상 노인 4,222명을 대상으로 구조방정식 모형 분석을 실시하였다. 분석결과는 다음과 같다. 첫째, 노인의 주관적 계층의식은 삶의 만족도에 영향을 미치는 것으로 확인되었다. 또한 노인의 주관적 계층의식이 우울에도 영향을 미치는 것으로 확인되었으며, 노인 우울 역시 삶의 만족도에 영향을 미치는 것으로 확인되었다. 즉, 노인의 주관적 계층의식이 높을수록 우울 수준은 낮고 삶의 만족도는 높은 관계가 나타났다. 둘째, 노인의 주관적 계층의식과 삶의 만족도의 관계에서 우울의 매개효과를 검증한 결과, 우울은 노인의 주관적 계층의식이 삶의 만족도에 미치는 영향을 매개하는 효과가 있는 것으로 나타났다. 이러한 연구결과를 근거로 노인의 주관적 계층의식을 높이고 우울 수준을 낮추거나 예방하여 삶의 만족도를 높일 수 있는 정책적, 실천적 함의를 제시하였다. 첫째, 노인의 주관적 계층의식을 높이기 위한 정책적 방안으로 주거 지원 정책과 여가활용지원을 통한 사회적 자본을 활용하고 강화할 수 있어야 한다. 둘째, 우울을 감소시키기 위하여 지역사회 기반의 네트워크 구축을 통한 노인 정신건강서비스 제공 등을 제안하였다.

• 한국산학기술학회논문지
• /
• 제18권10호
• /
• pp.569-579
• /
• 2017

본 연구는 부모로부터 경험한 청소년의 방임, 학대가 삶의 만족도에 영향을 미치는 관계에서 자아탄력성의 매개효과를 살펴보는 것이다. 이에 본 연구는 한국아동 청소년패널조사(Korean Children and Youth Panel Survey, KCYPS) 2015년 중학교 1학년을 대상으로 한 6차년도 자료를 활용하였다. 본 연구의 연구대상은 한국아동 청소년 패널조사 2015년 6차 데이터의 중학교 1학년생이다. 본 연구의 데이터는 구조방정식과 sobel testing에 의해 분석되었다. 연구결과는 부모에게 받은 방임, 학대가 중학생의 삶의 만족도 사이에서 중요한 매개효과를 갖는다는 것을 밝혔다. 연구결과의 내용은 다음과 같다. 첫째, 방임, 학대가 삶의 만족도에 부분적으로 영향을 미치는 것으로 나타났다. 구체적으로 방임과 자아탄력성은 부적 영향을 미치는 것으로 나타났다(${\beta}=-.258$, p<.001). 자아탄력성과 삶의 만족도는 정적 관계가 있는 것으로 나타났다(${\beta}=.843$, p<.001). 반면, 방임, 학대는 삶의 만족도에 유의한 영향을 미치지 않는 것으로 나타났다(${\beta}=-.005$, p<.001/${\beta}=-.035$, p<.001). 둘째, 완전매개모형을 경쟁모형으로 설정하여 부분매개모형과의 비교를 통해 적합한 모델을 평가한 결과 방임은 자아탄력성을 완전 매개하여 삶의 만족도에 영향을 미치는 것으로 증명되었다. 즉, 자아탄력성의 매개효과의 통계적 유의미성 검증, sobel검증을 실시한 결과 자아탄력성의 완전매개 효과가 통계적으로 유의미함이 검증되었다(Z=-.169, t(CR)=-.012 (p<.05). 본 연구의 결과를 바탕으로 실천적 함의가 논의되어졌다.