• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.373-377
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• 2012

This study was carried out in order to investigate the functional properties of 50% methanol extracts from four parts (root, stem, leaf and fruit) of Acanthopanax sessiliflorus by means of measuring the contents of eleutheroside B, E, and total polyphenols as well as determining electron donating ability (EDA), nitrite scavenging ability (NSA), and anticancer activity. The highest contents of eleutheroside B and E were found in the fruit (538.99 ${\mu}g/g$) and the stem (556.00 ${\mu}g/g$). The root extract demonstrated the highest polyphenol content (2.97 mg/g). EDA of the stem and root extracts were 90.21% and 85.71%. All of the extracts showed 81.5-93.0% of NSA at pH 1.2. In addition all extracts indicated no cytotoxicity to normal cell line (DC2.4). The root extract had a 23% inhibitory effect against the stomach cancer cell line (SNU-719). These results revealed that 50% methanol extracts from A. sessiliflorus can be used as a potential resource of nutraceuticals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.319-324
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• 2016

Soils with various particle sizes generally show good shear strength. Some soils have a relatively strong resistance to shear failure in spite of narrow particle distribution, such as gap grading. Based on this example, it can be inferred that appropriate arrangements of particle size in soils might result in an increase in shear strength. This study investigates the strength variation of soils with respect to the particle size distribution. Gap, well, and uniform graded soils were prepared with a desired ratio, and a wide range of direct shear tests were done using the prepared samples. The test results show that there is a strong relationship between the particle size ratio and internal frictional angle. Gap graded soil has a greater frictional angle than a well-graded sample, even when specimens have the same maximum particle size, which is also the case for the uniform grade specimen. The results have potential for developing a methodology for stronger soils through a simple manipulation of particle size distribution.

• Journal of the Korean Geotechnical Society
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• v.28 no.1
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• pp.29-39
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• 2012

The maximum unit point resistance ($q_{max}$) of rock socketed drilled shafts subjected to axial loads was investigated by a numerical analysis. A 3D Finite Difference Method (FDM) analysis and a Distinct Element Method (DEM) analysis were performed with varying rock elastic modulus (E), discontinuity spacing ($S_j$), discontinuity dip angle ($i_j$), and pile diameter (D). Based on the results of obtained, it was found that the ultimate point resistance ($q_{max}$) increased as rock elastic modulus (E) and rock discontinuity spacing ($S_j$) increased. But, it was found that $q_{max}$ decreased as pile diameter (D) increased. As for the influence of the dip angle of rock discontinuity ($i_j$), it was shown that $q_{max}$ decreased up to 50% of maximum value within the range of $0^{\circ}$ < $i_j$ < $60^{\circ}$ due to the shear failure at rock discontinuities. Furthermore, it was found that if $20^{\circ}{\leq}i_j{\leq}40^{\circ}$, influence of $i_j$ should be taken into account because $q_{max}$ tended to approach a minimum value as $i_j$ approached a value near the friction angle of the discontinuity (${\phi}_j$).

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.136-143
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• 2018

The rate pressure product (RPP) is expressed as a product of the heart rate and systolic blood pressure as an index indirectly measuring the myocardial oxygen consumption, and it indicates the burden on the myocardium. The aim of this study was to determine the optimal level of RPP for preventing metabolic syndrome in a treadmill exercise test in Korean adults. Metabolic syndrome was the diagnosis of the third executive summary report on the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. According to the criteria, the metabolic syndrome diagnosis group (MetS, N=25), pre-metabolic syndrome group (Pre-MetS, N=106), and non-risk factor group (Non-MetS, N=65) were classified. The exercise stress test was performed based on the Bruce protocol. The RPP was calculated as (heart rate${\times}$systolic blood pressure)${\div}1,000$. The results showed that the maximum systolic blood pressure was high despite the low daily dose reached in the diagnostic group of metabolic syndrome. The optimal threshold of the RPP at the time of the exercise treadmill test for a metabolic syndrome prediction was $12.56mmHg{\times}beats/min{\times}10^{-3}$ in the first stage of the exercise stress test. The second stage of the exercise test was $16.94mmHg{\times}beats/min{\times}10^{-3}$, and at the third stage of the exercise test was $21.11mmHg{\times}beats/min{\times}10^{-3}$.

• Journal of the Korean Geotechnical Society
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• v.30 no.7
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• pp.17-26
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• 2014

Tunneling-induced displacement in a jointed rock mass is an important factor to control tunnel stability and to secure a demanded space and construction quality. The magnitude of the inducible displacements is significantly affected by an elastic modulus and therefore, in a rock mass where a joint controls tunnel behavior, it is very important to estimate an elastic modulus of jointed rock mass reliably. Elastic modulus of jointed rock mass is affected by many factors such as rock type, joint condition, and loading condition. Nevertheless, most existing studies were focused on rough empirical relationships based on compressive loading conditions, which are different from tunnel excavation loading conditions, without a systematic approach of rock, joint, and loading conditions together. Therefore, this study considered rock and joint conditions systematically to estimate an elastic modulus of jointed rock mass under tunnel excavation loading. The controlled factors considered in this study are rock types and joint conditions (joint shear strength, joint inclination angle, number of joint sets, and joint spacing). Numerical parametric studies have been carried out with a consideration of different rock and joint conditions; the results have been compared with existing empirical relationships; and charts of elastic modulus change of different rock and joint conditions have been provided. The results are expected to have a great practical use for estimating the convergence induced by tunnel excavation in jointed rockmass.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.85-93
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• 2016

In this study, finite element analyses of masonry infilled frames using a general purpose FE program, ABAQUS, were conducted. Analysis models consisted of the bare frame, infilled frames with masonry wall thickness of 0.5B and 1.0B, respectively. The masonry walls were constructed using the concrete bricks which were generally used in Korea as infilled wall. The material properties of frames and masonry for the analysis were obtained from material tests. However, four times increased the tensile strength was used for 1.0B wall, which is seemingly due to the differences in locating the bricks. The force-displacement relation and development of crack from the FE analysis were very similar to those from the experiments. From the FEA results, contact force between the frame and masonry, distribution of shear force and bending moments in frame members were analyzed. Obtained contact stress shows a trianglur distribution, and the contact length for 0.5B speciment and 1.0B specimen were close to the value estimated using ASCE 41-06 equation and ASCE 41-13 equation, respectively. Obtained shear force and bending moment distribution seems to replicate actual behavior which originates from the contact stress and gap between the frame and masonry.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.32-38
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• 2005

Effects of supplemental charcoal powder and vitamin A on physico-chemical properties in 24 Hanwoo steers were investigated. The Hanwoo steers were randomly assigned to one of the three dietary treatments : 1) Control (commercial feed) 2) T1 (commercial feed supplemented with 2% charcoal powder and 0.2% vitamin A) 3) T2 (commercial feed with 2% charcoal powder). Crude fat content of proximate chemical composition in longissimus muscle was increased at control but moisture of control was rather lower than that of treatment groups (p<0.05). The WHC (water holding capacity) in longissimus muscle was tended to increase in control and shear force was higher in T2 (p<0.05). However, effects of diets charcoal power and vitamin A on pH were not found (p>0.05). Tenderness and flavor of sensory evaluation was improved significantly in control with peculiar and savory taste of Hanwoo being more emphasized. But Juiciness were not difference by treatments. When Hanwoo steers were fed with dietary charcoal powder and vitamin A, the palmitoleic acid and linoleic acid contents were higher compared with that of control (p<0.05), but oleic acid was higher in control than others.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.222-227
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• 2007

This study was carried out to investigate the influence of feeding eosungcho (Houttuynia cordata Thunb) powder on the meat quality of porks at chilled storage. Experimental groups were divided into control group (0%, C), 5% (T1) and 10% (T2) eosungcho powder feeding group, and then administered for 12 weeks. The results of sensory evaluation for softening value and scorched smell showed the highest preference in T1 group. Overall acceptability was also the highest in T1 group than the others. Physicochemical components were analyzed for pork loins that were stored at $4^{\circ}C$ for 23 days after vacuum packing. The moisture contents of pork loins were higher in T1 group than the others. Crude lipid contents were lower in T1 and T2 groups than the control group. The pH values were not significantly different in experimental groups during storage days. The Hunt L and a values increased significantly according to storage days. The Hunt b value was increased for the initial storage days but it did not change after 9 storage days. The Warmer-Bratzler share force of all experimental groups were greatly decreased between 2 and 9 storage days and then little exchanged afterwards.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.2
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• pp.141-154
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• 1993

In this paper, a method to calculate the ultimate compressive strength of welded one-sided stiffened plates simply supported along all edges is proposed. At first initial imperfections such as distortions and residual stresses due to welding are predicted by using simplified methods. Then, the collapse modes of the stiffened plate are assumed and collapse loads for each mode are calculated. Among these loads, the lowest value is selected as the ultimate strength of the plate. Collapse modes are assumed as follows ; (1) Overall buckling of the stiffened plate$\rightarrow$Overall collapse due to stiffener bending (2) Local buckling of the plate part$\rightarrow$Local collapse of the plate part$\rightarrow$Overall collapse due to stiffener yielding (3) Local buckling of the plate part$\rightarrow$Overall collapse due to stiffener berthing (4) Local buckling of the plate part$\rightarrow$Local collapse of the plate part$\rightarrow$Overall collapse due to stiffener tripping. The elastic large deflection analysis based on the Rayleigh-Ritz method is carried out, and plastic analysis assuming hinge lines is also carried out. Collapse load is defined as the cross point of the two analysis curves. This method enables the utimate strength to be calculated with small computing time and a good accuracy. Using the present method, characteristics of the stiffener including torsional rigidity, bending and tripping can also be clarified.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.3
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• pp.37-42
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• 2001

The concerns of the toxicity and health hazard of lead in solders have demanded the research to find suitable lead-free solder alloys. It was discussed that effect of the intermetallic formation and structure on the reliability of solder joints. In this study, lead-free solder alloys with compositions of Sn/3.5Ag/0.75Cu, Sn/2.0Ag/0.5Cu/2.0Bi were applied to the 48 $\mu$BGA packages. Also, the lead-free solder alloys compared with eutectic Sn/37Pb solder using shear test under various aging temperature. Common $\mu$BGA with solder components was aged at $130^{\circ}C$, $150^{\circ}C$ and $170^{\circ}C$. And the each temperature applied to 300, 600 and 900 hours. The thickness of the intermetallics was measured for each condition and the activation energy for their growth was computed. The fracture surfaces were analyzed using SEM (Scanning Electron Microscope) with EDS (Energy Dispersive Spectroscopy). These results for reliability of lead-free interconnections are discussed.