• Journal of Nutrition and Health
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• 제35권8호
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• pp.863-869
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• 2002

Soy isoflavones have been hypothesized to exert hormonal effects and to enhance bone mineral density in postmenopausal women. To test this hypothesis, we studied the effects of soy isoflavones supplements on bone mineral density and sex hormones (serum estradiol, sex hormone-binding globulin and testosterone) in 47 postmenopausal women. There were 24 participants in the treatment group and 23 in the control group. The treatment group consumed the isoftavones extract capsule daily (which contained 90 mg of soy isoflavones) for 12 weeks. The study compared pre- and post-isoflavones intake in the following areas: physical examination, diet survey, bone mineral density and serum sex hormone levels. The average age of the treatment group was 64.63 years and that of the control group was 66.48 years. There were no significant differences between the two groups in terms of height, weight, and body mass index. Both groups maintained regular diet patterns in terms of their average daily nutrient intake. There was no significant difference between the treatment group (18.49 mg) and the control group (21.27 mg) in terms of daily isoflavones intake based on diet. The 12-week analysis of bone mineral density change after taking isoflavones supplements demonstrated no significant differences in the following : lumbar spine BMD (0.82 g/$\textrm{cm}^2$ in pre versus 0.81 g/$\textrm{cm}^2$ in post), femoral neck BMD (0.58 g/$\textrm{cm}^2$ in pre versus 0.57 g/$\textrm{cm}^2$ in post) in the treatment group. There was no significant difference in serum estradiol in the isoflavones treatment group. The subjects indicated no significant difference in serum testosterone in the isoflavones treatment group. But the subjects indicated a significant difference in sex hormone-binding globulin (60.04 nmol/L in pre versus 52.39 nmol/L in post) in the isoflavones treatment group at the levels of p < 0.05. The significant decrease in sex hormone-binding globulin did indicate the need for long-term study on isoflavones supplementation as well as its positive effect on bone mineral density.

• 치과방사선
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• 제29권1호
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• pp.299-308
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• 1999

Purpose: The purpose of this study was to compare the qualities of the four different processing chemicals (solutions). Materials and Methods: With EP 21 films(Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor(XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient' s intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer(model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. Results: The results were as follows, 1. For the base plus fog density. there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90. Agfa and Konica. 2. For the film density. all chemicals showed useful range of photographic densities(0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). Conclusion: These results indicated that the four processing chemicals had clinically useful film density and contrast. but only Kodak processing chemical had useful base plus fog density.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.1957-1963
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• 2015

본 연구의 목적은 불안정 지지면에서의 동적 안정화 운동이 배가로근과 뭇갈래근의 두께와 밀도 및 백색영역지수(white area index, WAI)에 미치는 영향을 연구하였다. 연구대상은 20대 성인 27명이며 세 그룹으로 나누어 각기 다른 면에서 동적 안정화 운동을 6주 동안 실시하여 실험 전 후에 배가로근과 뭇갈래근의 두께와 근육 밀도, 백색영역지수를 측정하였다. 그 결과 세 그룹 간 의미있는 차이를 보였다(p<.05). 반복측정분산분석(repeated ANOVA) 결과, 배가로근과 뭇갈래근의 두께가 시기별 차이에서 그룹 간 의미있는 차이를 보였으며(p<.05), 뭇갈래근의 근육 밀도와 백색영역지수의 그룹 간 비교결과 의미있는 차이를 보였다(p<.05). 결론적으로 불안정 지지면에서 허리부 안정화 운동의 효과에 의미있는 차이가 있었고 이 같은 결과는 허리안정화 운동에 대한 추후 연구에 기초 자료로 활용 가능할 것으로 보인다.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.816-826
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• 2017

In this paper, a generalized discretization scheme is proposed that can derive general-order finite difference equations representing the joint probability density function of dynamic response of stochastic systems. The various order of finite difference equations are applied to solutions of the Fokker-Planck-Kolmogorov (FPK) equation. The finite difference equations derived by the proposed method can greatly increase accuracy even at the tail parts of the probability density function, giving accurate reliability estimations. Compared with exact solutions and finite element solutions, the generalized finite difference method showed increasing accuracy as the order increases. With the proposed method, it is allowed to use different orders and types (i.e. forward, central or backward) of discretization in the finite difference method to solve FPK and other partial differential equations in various engineering fields having requirements of accuracy or specific boundary conditions.

• 한국수산과학회지
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• 제47권6호
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• pp.707-712
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• 2014

The effects of transport stocking density (500, 600 and 700 kg of olive flounder Paralichthys olivaceus/per water tank) on the physicochemical characteristics of muscle were investigated. Transport of the animals took, on average, 10 days from Busan, Korea, to Long Beach, CA, USA. There was no significant difference in the breaking strength of muscle among the three groups. There was also no significant difference in the ATP, lactate, or glycogen content of muscle from the 500 and 600 kg/tank stocking density groups at the beginning and after transport. However, the ATP content decreased sharply while the lactate content increased in muscle from fish transported at a density of 700 kg/tank at the beginning of transport, and the ATP and lactate contents in this group were stable after transport.

• 한국과학교육학회지
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• 제11권1호
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• pp.15-24
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• 1991

The purpose of this study was to investigate the effectiveness of Learning Cycle approach to change the concept of density. The results of the study were as follows : 1) Students already had various types of preconception related to density before formal learning. These preconceptions mostly differ from scientific concepts. 2) Male students were much better than female ones in the development of scientific concepts before formal learning. These differences were found statistically significant(P<0.01). 3) The higher the cognitive level of the students, the better the development of scientific concepts. 4) In the change of preconceptions to scientific concepts by treatment, there was significant difference between control group and experimental group at the 0.05 level. It was found that Learning Cycle approaches were more effective than traditional approaches in acquiring the concept of density. 5) It was found that there was no significant difference On the retention level of the concept of density between control group and experimental group.

• 지질공학
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• 제9권3호
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• pp.253-265
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• 1999

충청북도 제천 지역에 있는 갑산층 퇴적암을 대상으로 지구물리검층과 실내 코어물성 측정에 의한 물성 반응 특성을 연구하였다. 자연감마와 전기비저항 및 밀도를 대상으로 하여 지구물리검층과 실내 코어물성 사이에 나타나는 유사성과 차이점을 비교하는데 초점이 모아졌으며 특히 물리검층과 실내 코어물성 사이에 나타나는 차이점 분석 과정을 통하여 검층밀도 결정에 있어서 자연감마의 영향을 분석하였다. 자연감마의 영향 보정에 의하여 두 물성간의 상관성이 개선되고 검층해석 결과에서 신뢰도가 크게 향상되었다. 물성 값중에서는 갑산층 셰일의 밀도가 주변의 치밀질 석회암보다도 높게 나타나고 있음이 주목되었다.

• Applied Microscopy
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• 제50권
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• pp.6.1-6.6
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• 2020

The cerebellum is a region of the brain that plays an important role in motor control. It is classified phylogenetically into archicerebellum, paleocerebellum and neocerebellum. The Purkinje cells are lined in a row called Purkinje cell layer and it has a unique dendritic branches with many spines. The previous study reported that there is a difference of synapse density according to the lobules based on large two-dimensional data. However, recent study with high voltage electron microscopy showed there was no differences in dendritic spine density of the Purkinje cell according to its phylogenetic lobule. We analyzed Purkinje cell density in the II, VI and X lobules by stereological modules and synaptic density was estimated by double disector based on Purkinje cell density in the molecular layer of each lobule. The results showed that there was significant difference in the Purkinje cell density and synapse number according to their phylogenetic lobules. The number of Purkinje cell in a given volume was larger in the archicerebellum, but synapse density was higher in the neocerebellum. These data suggest that cellular and synaptic organization of the Purkinje cell is different according to their phylogenetic background.

• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.185-192
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• 2009

Purpose: The aim of this study was to examine the correlation of the subjective and the objective evaluation of edentulous ridge bone quality, and to evaluate the change of the dental implant stability in each bone density group for early healing period after implant installation. Methods: Sixty-seven implants(Osstem implant$^{(R)}$, Seoul, Korea) were included in this study. We evaluated the bone density by 2 methods. The one was the subjective method which was determined by practitioner s tactile sense, the other was the objective bone type was based on Hounsfield units. The implant stability in each bone type group was assessed by resonance frequency analyzer(Osstell mentor$^{(R)}$). Data were analyzed for the change of the implant stability, and they were compared to verify the difference of groups at the time of installation, 2, 6, 10, 14 weeks postoperatively. Spearman's correlation was used to demonstrate the correlation between the subjective and the objective evaluation of the bone density, and analysis of variance(ANOVA) was used to analyze the differences of implant stability at each time point. Results: There was no close relation between the subjective and the objective evaluation of the bone density(r=0.57). In the subjective groups, there was statistically significant difference between the type 1 and 3 at 10 weeks and between the type 2 and 3 at 14 weeks. In the objective groups, there was no statistically significant difference between the D 1, 2, 3, 4, and 5 group with regard to RFA from baseline to 14 weeks(P>0.1). Conclusions: The implant stability increased over time during the study, and it was improved with bone density proportionally after 2weeks postoperatively. It is recommended that the decision of bone density is base on Hounsfield unit for implant loading time.

• 대한기계학회논문집B
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• 제33권10호
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• pp.783-788
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• 2009

In this paper, we have performed a parametric study on the characteristics of multiphase laminar flow with density difference in various microchannels. The interface between multiphase fluids is rotated by the gravitational forces induced by density difference. The numerical simulations were carried out via commercial CFD package to study the characteristics of multiphase laminar flow. The results of the numerical simulations in this study were verified by comparing with the previously reported experimental results in the literature. We have also proposed a new dimensionless relationship between dimensionless rotation angle of interface and dimensionless parameters are proposed for square microchannels with various aspect ratios. The dimensionless relationship could be widely applied to the reliable design of various microfluidic devices dealing with multiphase laminar flow.