• 가족자원경영과 정책
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• 제20권4호
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• pp.35-47
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• 2016

This research aimed to observe adolescent children's use of time and to discover the parent-related factors that affect adolescent children's use of time. The subjects included 2,092 fourth-grade elementary school students and 2,108 first-grade middle school students. We used data from the Korean Children and Youth Panel Survey. We tested sociodemographic factors, parents characteristics, and time usage, and we studied these factors using SPSS version 23.0; the results are as follows. Firstly, in the subordinate scope of the child-rearing attitude of parents, affection fourth-grade elementary school students(M = 1.83) and first-grade middle school students(M = 2.02). Inconsistency had an effect on fourth-grade elementary school students(M = 1.99), and first-grade middle school students(M = 2.12). Excessive expectations had an effect on fourth-grade elementary school students(M = 2.40) and first-grade middle school students(M = 2.55). Over-involvement had an effect on fourth-grade elementary school students(M = 2.68)and first-grade middle school students(M = 2.80). Finally, giving reasonable explanations had an effect on fourth-grade elementary school students(M = 1.51)and first-grade middle school students(M = 1.68). Secondly, in fourth-grade elementary school students(M = 463.35) and first-grade middle school students(M = 378.75). Further, studying hours during weekdays had an effect on fourth-grade elementary school students(M = 456.15) and first-grade middle school students(M = 460.86). Free activity hours during had an effect on fourth-grade elementary school students(M = 390.54) and first-grade middle school students(M = 387.11). Sleeping hours during holidays had an effect on fourth-grade elementary school students(M = 544.85) and first-grade middle school students (M = 511.74). Studying hours during holidays had an effect on fourth-grade elementary school students (M = 484.86) and first-grade middle school students (M = 511.74). Free activity hours during holidays had an effect on fourth-grade elementary school students(M = 518.68) and first-grade middle school students(M = 509.73). Thirdly, by observing the relative influence of related factors on adolescent children's use of time, grade(${\beta}$ = -.284), gender(${\beta}$ = -.208), over-involvement(${\beta}$ = -.380), supervising(${\beta}$ = -.217), and (${\beta}$ = .243) in terms of the child-rearing attitudes of parents was found to affect study hours($F=2.595^{**}$). The education level of fathers(${\beta}$ = -.144) results in(${\beta}$ = 1.991) and longer free activity hours for children($F= 4.116^{***}$). This research can be used to study the influence of parents'child-rearing attitudes on adolescent children's use of time and to suggest the role of parents in adolescents' ability to manage time effectively using practical.

• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.88-92
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• 2006

This study is intended to check the flame temperature to raise in burning grade C heavy fuel oil and emulsion fuel oil in a boiler and to measure the concentration of Dry Shoot(DS) and Soluble Organic Fraction(SOF) after collecting the Particulate Matters (PM). The flames temperature in boiler was measured by burning grade C heavy oil and oil-water emulsion (C heavy oil $70\%\;and\;30\%$ of water) Combustion characteristics of two fuels was also compared by trapping particulate matters (PM) in exhaust gas and measuring the generated quantities of DS and SOF in fuel gas.

• 대한지구과학교육학회지
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• 제12권2호
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• pp.119-130
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• 2019

TIMSS 평가는 4년 간격으로 실시되는데, 우리나라의 경우에는 TIMSS 2011에서 4학년으로 평가에 참여하였던 학생 모집단이 4년 뒤인 TIMSS 2015에서 8학년으로 다시 평가에 참여함으로써, 우리나라가 TIMSS 평가에 참여한 이래 처음으로 코호트 집단의 초등학교와 중학교 성취도 자료를 얻었다. 이에 본 연구에서는 초4에서 중2로 학년 및 학교급이 바뀌면서 나타나는 우리나라 학생들의 성취도 급락의 원인을 탐색하기 위해, TIMSS 2011의 초4와 TIMSS 2015의 중2에 공통으로 사용된 설문 문항들을 분석함으로써, 성취도 상위 5개국을 중심으로 학생 특성, 교사 특성 그리고 교실수업 특성과 관련된 교육맥락변인들의 변화를 분석하였다. 연구결과에 따르면 학생들의 학교 소속감은 초4에서 중2로 가면서 증가한 반면에, 과학 수업에 대한 학생들의 인식은 대부분의 항목들에서 긍정적 인식의 비율이 낮아지는 것으로 나타났다. 교사 특성과 관련하여, 교사의 전문성 개발 활동은 초4에서 중2로 가면서 더 증가하였고, 과학교사의 수업에 대한 자신감은 국제평균과 유사한 경향을 나타내었다. 교실수업 특성과 관련하여, 과학수업에서 탐구 관련 활동 유형별 빈도는 초4에서 최상위 수준이다가 중2에서 국제평균보다 더 낮아지는 것으로 나타났다. 연구결과를 토대로 우리나라 과학과 교수학습에 주는 시사점을 학교급별로 성취도 향상을 위한 차별화된 전략 마련의 필요성, 학생 참여형 수업으로 전환할 필요성, 과학 흥미에 영향을 주는 교육맥락변인에 대한 지속적인 연구의 필요성, 학생 성취도에 미치는 교사 수준의 교육맥락변인에 대한 심층연구의 필요성 등의 측면에서 제안하였다.

• 한국연초학회지
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• 제6권2호
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• pp.215-219
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• 1984

This experiment was conducted to investigate the effect of physical and chemical characteristics of lower grade tobacco with treatment of ozone. In ozonization of low grade tobacco, optimum moisture was 20 percentage, and decrease ratio of content of tobacco leaf was 30 percentage in nicotine , 15.9 percentage in total volatile base, 10.5 percentage in petroleum-ether-extract, 29.5 percentage in solanesol, and decrease ratio of cigarette smoke composition was 31 percentage in nicotine, 6.08 percentage in tar.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1490-1491
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• 2007

The salt contamination on the distribution facilities, such as suspension insulator, line post insulator, lightning arrester, COS, is one of the major coastal areas because more than 90% of salt contaminated failure occurs in distribution facilities. Did to stain distribution facilities artificially according to Equivalent Salt Deposit Density(ESDD) grade. The electrical test were performed on the non-polluted and polluted facilities(ESDD B, C, D grade).

• Human Ecology Research
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• 제51권4호
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• pp.371-382
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• 2013

The purpose of this study is to investigate children's emotional problems (attention problem, aggression, somatic symptom, social withdrawal, depression) and to examine the relationship between children's emotional problems with family characteristics (parent education, parent job, family income), life-styles (gaming times, TV times, sleep time). The sample was 2,140 collections of second grade children and their parents who participated in Korea Youth Panel Survey on 2011. We analyzed the data which were collected by means of questionnaires and the data were analyzed with t -test, ANOVA, Pearson correlation analysis, and regression analysis with SPSS ver. 19.0. The results were summarized as follows. The level of children's emotional problem was relatively low on average. There is a significant difference in the children's emotional problems according to family characteristics and life-styles. There was a relationship between children's emotional problems (attention problem, aggression, somatic symptom, social withdrawal, depression) and life-styles (gaming times, TV times). The significant factors influencing the children's emotional problems are connected with father's education, mother's job, family income, family characteristics, gaming time and TV time of life style. It is noted that parent education level was an important factor for children's attention problem and aggression. Amongst children's life-styles, gaming time and TV time are negative factors for social withdrawal and depression.

• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.167-171
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• 2012

Objective : The aim of this study was to compare clinical characteristics of ruptured aneurysms in young adults, of the third and fourth decades of life, and to compare several clinical characteristics affecting the outcome of patients. Methods : We retrospectively investigated 1459 patients who underwent surgery and endovascular treatment for ruptured cerebral aneurysms from June 1992 to December 2010 and compared clinical characteristics. We also reviewed pre-existing medical conditions and perioperative complications. Results : Among 1459 patients, there were 21 patients (1.44%) in the third decade and 104 patients (7.13%) in the fourth decade of life. Within two age groups, 88 (70.4%) were male and 37 (29.6%) were female, a ratio of 2.37 : 1. In both groups, we observed the anterior cerebral artery (ACA) aneurysm with the most frequency (p=0.028). In general, favorable outcome was achieved in both age groups (90.5% and 81.7%, respectively). An initial univariate analysis showed Hunt-Hess grade, Fisher grade, location of aneurysm, and rebleeding significantly associated with outcome after aneurysm rupture. Further, multivariate analysis demonstrated that only Hunt-Hess grade (grade 4-5) was a risk factor for the outcome (odds ratio=9.730, 95% confidence interval 2.069-45.756, p=0.004). Conclusion : The incidence of subarachnoid hemorrhage (SAH) was higher in the male population of the third and fourth decades of life. Aneurysms on the ACA were most frequently occurred in both age groups and the outcome of aneurysmal SAH among the third and fourth decades was favorable. Multivariate analysis revealed that high Hunt-Hess grade was a risk factor for patient's outcome.

• 공업화학
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• 제28권3호
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• pp.313-317
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• 2017

지속적인 에너지 수요의 증가로 인하여 저등급 석탄이 새로운 에너지 자원으로서 인정받고 있다. 그러나 저등급 석탄의 높은 수분 함량으로 인하여 저등급 석탄의 이용 효율은 기존의 석탄 이용 플랜트들에서 이용하기에 부족하다. 따라서 저등급 석탄의 수분 함량을 낮추는 건조 공정이 요구되고 있다. 비록 다양한 건조 실험들이 진행되었으나, 고압조건에서의 건조 특성은 크게 연구되지 않았다. 이에 본 연구에서는 높은 수분 함량을 지닌 저등급 석탄(수분 함량: 21.5 wt%)의 급속 건조 특성을 가압 마이크로 상승관을 이용하여 고찰하였다. 압력(1-40 bar), 건조 온도($200-600^{\circ}C$), 마이크로 상승관 길이(2-6 m) 등의 운전 조건 변화에 따른 저등급 석탄의 건조 특성을 분석하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권12호
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• pp.1781-1789
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• 2013

Many studies have been carried out with respect to packaging methods and temperature conditions of beef. However, the effects of packaging methods and temperature conditions on the quality characteristics have not been extensively studied in low-grade beef. Low-grade beef samples were divided into 3 groups (C: ziplock bag packaging, T1: vacuum packaging, and T2: modified atmosphere packaging (MAP), $CO_2/N_2$ = 3:7) and samples were stored at $4^{\circ}C$ for 21 days. The water-holding capacity (WHC) was significantly lower in T1 than in the other samples up to 14 days of storage. The thiobarbituric acid reactive substances and volatile basic nitrogen values were significantly lower in T1 and T2 than in C after 7 to 14 days of storage. The total bacterial counts were significantly lower in T1 and T2 than in C after 14 days of storage. In a sensory evaluation, tenderness and overall acceptability were significantly higher in T1 and T2 than in C at the end of the storage period (21 days). We propose that the MAP method can improve beef quality characteristics of low-grade beef during cold storage. However, the beneficial effects did not outweigh the cost increase to implement MAP.

• Journal of the Korean Wood Science and Technology
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• 제38권1호
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• pp.49-55
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• 2010

본 연구에서는 국내 수종 중 낙엽송(Larix Kaemferi Carr)을 대상으로 하여 톱밥의 특성별, 형태별로 나누어서 제조된 목재펠릿의 특성변화를 조사하였다. 제조된 펠릿의 함수율, 밀도, 회분, 흡습율, 발열량을 측정하여 비교하였다. 펠릿제품의 함수율은 6.4~7.31%로 나타나 목재펠릿의 품질기준 1급인 10% 이하를 만족시켰고, 대팻밥으로 제조한 펠릿의 밀도가 가장 높았고, 톱밥의 종류별 제조된 펠릿의 밀도는 큰 차이가 없었으며, 품질규격 1급을 만족시켰다. 회분은 0.2~0.424%로 품질규격 1급인 0.7% 미만의 범주에 속한 것으로 나타났으나, 수피만으로 제조된 펠릿의 회분량은 2.106%로 상당히 높은 값을 보여 1.5% (2급)을 초과하였다. 흡습율은 수피를 사용한 경우 추출물성분에 의해 수분 흡수 저해 효과가 있는 것으로 나타났으며, 제조된 각 펠릿의 발열량 측정결과 품질기준(1급) 4,300 kcal/kg을 넘어섰다.