• 대한지역사회영양학회지
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• 제3권3호
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• pp.380-388
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• 1998

This study was conducted to investigate the distribution of bone density according to age and the prevalence rate of osteoporosis I 613, middle-aged women who visited Saint Bundo Hospital in Pusan from June to December, 1997. Mean bone density of lumbar spine(L2L4), and femoral neck of 50-59 years of age was significantly lower than those of 40-49 years of age(p<0.05). At the 60years of age, mean bone density of two sites were less than those of 50-59 years of age. Mean bone density of lumbar spine tin the group of sixties were 20.7% lower than that of group aged under 40 ; For femoral neck, women in their sixties showed 22.6% lower density compared to the women aged under forty. Bone density of ward's triangle of sixties were the least, which was 34.2% lower than that of group aged under 40. Bone density in lumbar spine, femoral neck, trochanter and ward's triangle correlates strongly with each other(p<0.001). The proportion of osteoporosis was 3.6% in the group of forties, 10.9% in the group of fifties and 33.8% for the group aged over 60, which was assessed by bone density of lumbar spine. Bone density of lumbar spine, femoral neck and ward's triangle were positively correlated with height, weight and BMI(p<0.001∼p<0.01), and weight showed highest correlation with the bone density. Forty-four percent of variation in lumbar spine bone density was explained by age and weight.

• 대한화학회지
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• 제61권3호
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• pp.112-121
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• 2017

본 연구는 수압 공식을 이용한 설명 대신, 밀도와 중력의 개념을 연결한 설명이 뜨거나 가라앉는 현상에 대한 학생들의 대안 개념에 어떠한 영향을 미치는가를 알아보고자 하였다. 연구 대상은 강원도에 위치한 한 고등학교 2학년 4개반, 140명의 학생들이었으며, 이들을 실험집단과 비교집단의 두 집단으로 나누었다. 실험집단에는 밀도와 중력 개념을 연계한 설명을 도입한 수업을, 비교집단은 교과서에 제시된 수압 공식을 이용한 설명을 도입한 수업을 각각 실시하였다. 사전검사 결과를 공변수로 하여 공변량분석(ANCOVA)을 한 결과, 물질의 특성과 관련된 3 문항 중 2개 문항은 두 집단 간 차이가 통계적으로 유의하지 않았으나, 1개 문항은 수업의 작은 효과크기(Hedges' g=0.327)를 보였다. 그리고 대안개념 변화 추이에서도 두 집단 사이에 유의미한 차이가 없었다. 반면, 물과 물체와의 상대적 무게 관계와 관련된 문항에서는 3개 문항 모두 두 집단 간 차이가 통계적으로 유의미한 효과크기(0.286~0.502)를 나타내었다. 뿐만 아니라 사후에 실험집단의 압력과 관련된 대안개념의 빈도수가 비교집단에 비해 상당히 감소하였다. 따라서 이 연구에서 제안한 무게와 밀도를 연계한 설명 방식은 뜨고 가라앉는 현상에 대한 학생들의 대안개념을 제거하고 과학적 개념을 형성하는데 효과적임을 알 수 있다.

• 한국작물학회지
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• 제38권2호
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• pp.189-195
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• 1993

본시험은 유ㆍ무한신육형콩의 생육 및 수량형질의 차이와 그 변이 정도를 구명하고 콩 육종 및 재배의 기초자료를 얻고자 1990년 수원 작물시험장에서 실시하였다. 유한신육형인 황금콩과 장엽콩, 무한신육형인 Clark와 Qilliams를 공시하여 재식밀도는 휴폭을 60cm로 동일하게 하고 주간을 10cm (밀도, 33개체/$m^2$), 15cm(표준, 22개체/$m^2$) 및 20cm(소식, 16개체/$m^2$)로 달리하여 생육 및 수량형질의 재식밀도 반응을 검토한바 그 주요결과를 요약하면 다음과 같다. 1. 단위면적당($m^2$) 분지수와 분지절수는 유한신육형이 무한신육형 보다, 단위면적당($m^2$) 주경절수는 무한신육형이 유한신육형 보다 많았으며 밀식일수록 증가하였다. 2. 단위면적당($m^2$) 입종은 유한신육형이 무한신육형보다 많았고, 밀식일수록 많았다. 3. 수량구성요소의 주경의존도는 밀식일수록 높아 졌는데 이러한 경향은 유한신육형 보다 무한신육형에서 더 컸다. 4. 입경비는 무한신육형이 유한신육형 보다 높았으며 소식일수록 증가하였고,면적경중은 유한신육형이 무한신육형 보다 많았으며 밀식일수록 증가하였다. 5. 개체간 변이 분석 수량형질 > 개체전체의 수량형질 > 주경의 수량 형질 > 주경의 형태적 형질 및 100입종의 순으로 컸으며 유ㆍ무한신종육형간에 뚜렷한 차이는 분지 관련 형질이었다. 6. 재식밀도 변화에 따른 개체간 변이의 변동이 큰 형질은 분지의 수량형질로서 무한신육형이 유한신육형에 비하여 변이폭이 컸다.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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• pp.450-455
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• 2008

We have carried out the test using the cone calorimeter and the smoke density chamber to evaluate the characteristics of the combustion for the car interior materials passed horizontal burning test. We have analysed many parameters related to fire hazard. These parameters are the ignition time, the heat release rate, the maximum average rate of heat emission, the flashover propensity and specific optical density. There was a significant difference in HRR and optical smoke density. The HRR was $185{\sim}446kW/m^2$ and optical smoke density was $119{\sim}1207$. Only horizontal burning test was performed to evaluate the fire hazard for the car interior materials.

• Carbon letters
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• 제13권3호
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• pp.151-156
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• 2012

This study considered the effect of the heat treatment temperature on the compressive strength of coal powder compacts affected by density, porosity, and crystallinity. Coal powder compacts were made by pressing of milled coal powder and were heat treated at 200, 400, 600, 800, and $1000^{\circ}C$. The density and porosity of the heat treated specimens at each temperature were measured using the Archimedes method and changes in crystallinity were analyzed using Raman spectroscopy. Increases in compressive strength at $600^{\circ}C$ or higher temperatures were proportionally related to increases in the density and the degree of crystallinity.

• Journal of Magnetics
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• 제18권4호
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• pp.417-421
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• 2013

The dominant magnetization reversal behavior of electrodeposited CoPt samples with various thicknesses deposited at different current densities was the domain wall motion by means of wall pinning. The magnetic interaction mechanism was dipolar interaction for all samples. The dipolar interaction strength was significantly affected by the sample thickness rather than by the current density, while the magnetic properties were closely related to the current density.

• Journal of the Optical Society of Korea
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• 제20권3호
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• pp.427-430
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• 2016

The effect of the liquid density difference on interface shape of a double-liquid lens is analyzed in detail. The expressions of interface shape of two liquids with liquid density difference are analyzed and fitted with “even asphere”. The imaging analysis of the aspheric interface shape of a double-liquid lens is presented. The results show that the density difference of two liquids can cause the interface to be an aspheric surface, which can improve the image quality of a double-liquid lens. The result provides a new selection for the related further research and a wider application field for liquid lenses.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.963-968
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• 2008

For the [$Cr_2(H_2tmp)_2Cl_4$] compound, simplified models with two bridging methoxo ligands have been studied. The influence of the bridging Cr-O-Cr bond angles on the exchange coupling between metal atoms in the model compound has been analyzed by means of density functional calculations with the broken-symmetry approach. Coupling constant calculated for the full structure is in good agreement with the experimentally reported value, confirming the validity of the computational strategy used in this work to predict the exchange coupling in a family of related dinuclear Cr(III) compounds. The calculations indicate a good correlation between the calculated coupling constant and the sum of the squared energy gap of three pairs of metal $t_{2g}$ OMSOs with a limited variation of the Cr-O-Cr angle. The spin density distribution and the mechanism of magnetic coupling interactions are discussed.

• Journal of Acupuncture Research
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• 제26권2호
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• pp.91-101
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• 2009

Objectives: Osteoporosis is the most common metabolic disease of the bone, and is one of the most important major public health problems world wide. It is more occurred in female than male, but as the osteoporosis of men is increasing, therefore bone fractures of men are increasing. So we investigated the factors which are related to Bone Mineral Density(BMD) of male for prevention of osteoporosis. Methods: We measured the Bone Mineral Density(BMD) of lumbar spine($L_2$-$L_4$) and femoral neck in 5198 male, using dual energy X-ray absorptionmetry(DEXA; DPX-alpha). And then we analysed the 8 factors - age group, bone mass index(BMI), amount of smoking, drinking, exercise, and fast blood sugar, gastric disease, thyroid disease - which are related to BMD of male. Results: 1. In age group according to ${\ll}$Hwangjaenaekyong Somun, 黃帝內徑 素問${\gg}$, T-score was the highest at 17-24(三八歲) years group and decreased rapidly after 57-64(八八歲) years group in both lumbar spine($L_2$-$L_4$) and femoral neck. Therefore we concluded that T-score of male in lumbar spine($L_2$-$L_4$) and femoral neck change according to age group in ${\ll}$Hwangjaenaekyong Somun, 黃帝內徑 素問${\gg}$. 2. In BMI(body mass index), T-score of lumbar spine($L_2$-$L_4$) and femoral neck were the highest in obese group than non-obese group. In comparison of age group according to BMI, T-score of lumbar spine($L_2$-$L_4$) was significant difference in 17-72 years group and T-score of femoral neck was in 25-72 years group. 3. In exercise, T-score of lumbar spine($L_2$-$L_4$) and femoral neck was increasing as exercising more. In comparison of age group according to exercise, Both T -score of lumbar spine and femoral neck were significant difference in 25-72 years old. 4. T-score of lumbar spine($L_2$-$L_4$) was the highest in men who have taken exercise daily, and T-score of femoral neck was the highest in men who have taken exercise 1-3 times for a week. Conclusions : The age group in ${\ll}$Hwangjaenaekyong Somun, 黃帝內徑 素問${\gg}$ is related to BMD of men. And risk factors - BMI, exercise - are related to BMD of men. Therefore we expect that this study will help for prevention of osteoporosis of men.

• Journal of Nutrition and Health
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• 제33권1호
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• pp.59-67
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• 2000

The objective of this study was to investigate nutritional status of middle aged Korean men exhibiting impaired glucose tolerance (IGT) and identify the risk factors related to IGT Data were collected from 163 men with a fasting blood glucose level from 115 to 139mg/dl(high blood glucose group: HBG) and 170 men with a normal fasting blood glucose level(control) aged from 40 to 59 years in both groups. Weight, body mass index(BMI) and percent body fat were significantly higher in high blood glucose(HBG) group than those of control group. Age, weight, BMI, percent body fat were positively related to blood glucose. There were no differences in exercise, smoking and family history of diabetes between two groups. Frequency of fat eating and overeating of HBG were higher than those of control group but frequency of sweet snacks intake of HBG was lower than that of control group. There was no difference in daily total energy intake in two groups. Total and supper energy intakes were positively associated with blood glucose. Percent energy intake of alcohol was significantly higher in HBG group and positively related to blood glucose, however there were no difference in daily intake of nutrients in two groups. Alcohol intake was positively related to BMI, but after adjusting BMI, there was no correlation between alcohol intake and blood glucose. Serum total cholesterol and triglyceride were significantly higher in HBG group than those of control group. Serum total cholesterol i,nd triglyceride were positively related to blood glucose and high density lipoprotein cholesterol was negatively associated with blood glucose. After adjusting BMI, serum triglyceride was positively related to blood glucose. In conclusion, weight, BMI, percent body fat and blood total cholesterol, low density lipoprotein cholesterol and triglyceride levels were positively related to blood glucose level of middle aged Korean men exhibiting impaired glucose tolerance. Their eating habits exhibited higher frequency of overeating, fast eating, high energy intakes of supper. (Korean J Nutrition 33(1) : 59-67, 2000)