• Korean Journal of Exercise Nutrition
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• v.13 no.1
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• pp.29-35
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• 2009

The purpose of this study was to investigate the effects of oral supplementation of coenzyme Q10 (CoQ10) for 4 weeks on the plasma free oxygen radical and total antioxidant capacity at resting and after one bout exercise in healthy old men. Thirty volunteers with an average (+/-SD) age of 62.59+/-5.3 years participated in this study and were divided with three groups; CoQ10 (200 mg daily) group, vitamin C & E (800mg, 400 IU daily) group, and placebo group. A cycle exercise (60% HRR) test was performed at the end of study. Blood samples were taken for the analyses at rest and pre-, post-, 30min after cycle exercise, before and after the 4 weeks of supplementation. After supplementation, there were no significant differences in the plasma free oxygen radical levels and total antioxidant capacity at resting. Plasma free oxygen radical level and total antioxidant capacity in three groups were significantly elevated after exercise, however, it did not vary significantly between groups. CoQ10 supplementation showed significant difference in total antioxidant capacity during recovery phase compared with placebo group. Our results demonstrated that supplementation of CoQ10 in healthy old men improve blood total antioxidant capacity after one bout exercise, despite no alteration of plasma free oxygen radical levels.

• International Journal of Highway Engineering
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• v.16 no.1
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• pp.57-62
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• 2014

PURPOSES : Capacity is a main factor of determining the number of lane in highway design or the level of service in road on operation. Previous studies showed that breakdown may occur before capacity is reached, and then it was concluded that capacity is a stochastic value rather than a deterministic one. In general, estimating capacity is based on average over maximum traffic volume observed for capacity state. This method includes the empirical distribution method(EDM) and would underestimate capacity. This study estimated existing empirical methods of estimating stochastic highway capacity. Among the studied methods are the product limit method(PLM) and the selected method(SM). METHODS : Speed and volume data were collected at three freeway bottleneck sites in Cheonan-Nonsan and West Sea Freeway. The data were grouped into a free-flow state or capacity state with speeds observed in the bottlenecks and the upstream. The data were applied to the empirical methods. RESULTS : The results show that the PLM and SM estimated capacity higher than EDM. The reason is that while the EDM is based on capacity observations only, the PLM and SM are based on free-flow high volumes and capacity observations. CONCLUSIONS : The PLM and SM using both free-flow and capacity observations would be improved to enhance the reliability of the capacity estimation.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.3
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• pp.141-148
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• 2009

Purpose：The purpose of this study was analyze the effect combination exercise program on plasma total antioxidant capacity and free oxygen radical according to exercise frequency of elderly. Age range of subject is 65~70 years. Methods：Subjects divided into three groups: control group(0-time), week-3 times group(3-times), week-5 times group(5-times). Each group were performed combination exercise during 8 weeks. Results：The results of each group by ANOVA free oxygen radical have a change(p<.05). We performed comparison of total antioxidant capacity and free oxygen radical pre-test and post-test on each groups. Total antioxidant capacity was increased in the 3-times and 5-times groups but there have not significant. Total antioxidant capacity is improve better than to 5-times. Free oxygen radical is significant increased in the 0-time (p<.05). But 5-times but 3-times is no significant decrease. Free oxygen radical is improve better than to 3-times. Conclusion：In the old people, exercise frequency week 3 times doing appeared effectively in improvement of the free oxygen radical and 5 times doing appeared effectively in improvement of the total antioxidant capacity. So rightly must apply a exercise frequency well in characteristic of old person each person.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3677-3691
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• 2023

Since containment building is the major shielding structure to ensure safety of nuclear power plant, the structural behavior and ultimate pressure capacity of containments must be studied in depth. This paper addresses ambiguous issue of determining free-field position for liner failure by suggesting an expanded free-field region and comparing internal pressure capacities obtained by test data, conservative assumption and suggested free-field region. For this purpose, a practical approach to determine the free-field position for the evaluation of liner tearing is carried out. The maximum principal strain histories versus internal pressure capacities among different free-field positions at various azimuths and elevations are compared with those at the equipment hatch as a conservative assumption. The comparison shows that there are considerable differences in the internal pressure capacity at liner failure within the expanded free-field region compared to the vicinity of the equipment hatch. Additionally, this study proposes an approximate correlation with conservative factors by considering the expanded free-field ranges and material characteristics to determine realistic failure criteria for liner. The applicability of the proposed correlation is demonstrated by comparing the internal pressure capacities of full-scale containment buildings following liner failure criteria according to RG 1.216 and an approximate correlation.

• ETRI Journal
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• v.40 no.3
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• pp.330-336
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• 2018

Free-space optical (FSO) systems have attracted much attention from both research and application perspectives owing to their many benefits, such as license-free operation, low-cost, and high data rates. This paper investigates the ergodic capacity of FSO systems, which is an important metric of system performance. The stochastic temporary laser-beam blockage, pointing errors, and atmospheric turbulence are simultaneously considered. The results illustrate that the link blockage causes a decreased ergodic capacity. We show that to maximize the ergodic capacity, there is an optimal value of the laser-beam radius at the waist, which largely depends on pointing errors; however, it is independent of the atmospheric turbulence and the probability of link blockage.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.1-8
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• 2018

Objectives : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix and Angelicae Dahuricae Radix. Each of herbal medicines has studied on anti-oxidant effect. So this study was conducted to investigate efficacy and potency of JMB on anti-oxidation. Methods : The JMB was extracted at room temperature by 80% ethanol. And total polyphenol contents, total flavonoid contents in JMB ethanol extract were determined by colorimetric method. Also, DPPH, ABTS free radical scavenging capacity and reducing power of JMB ethanol extract were measured at 100, 500, 1000, $5000{\mu}g/m{\ell}$ concentrations by spectrometric assay. Positive control was used BHA (butylated hydroxyanisole). Results : The total polyphenol contents and total flavonoid contents of the extract were 55.38 mg/TAEg, 513.72 mg/RUEg, respectively. Also, DPPH free radical scavenging capacity and reducing power of JMB ethanol extract in treated concentrations (100, 500, 1000, $5000{\mu}g/m{\ell}$) increased dose dependently. In particular, DPPH free radical scavenging capacity of JMB ethanol extract at 500, 1000, $5000{\mu}g/m{\ell}$ was similar to positive control (BHA) at high concentration (50, $100{\mu}g/m{\ell}$). ABTS free radical scavenging capacity of JMB ethanol extract at 500, 1000, 5000 ug/ml was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Also, reducing power was showed that JMB ethanol extract at $5000{\mu}g/m{\ell}$ was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Conclusions : These results suggest that JMB ethanol extract has effects to scavenge free radicals. Therefore, JMB has potential and applicable benefits for development of materials and products to have anti-oxidation functions.

• Corrosion Science and Technology
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• v.8 no.2
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• pp.81-88
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• 2009

Chloride induced corrosion of steel reinforcement inside concrete is a major concern for concrete structures exposed to a marine environment. It is well known that transport of chloride ions in concrete occurs mainly through ionic/molecular diffusion, as a gradient of chloride concentration in the concrete pore solution is set. In the process of chloride transport, a portion of chlorides are bound in cement matrix then to be removed in the pore solution, and thus only the rest of chlorides which are not bound (i.e. free chlorides) leads the ingress of chlorides. However, since the measurement of free/bound chloride content is much susceptible to environmental conditions, chloride profiles expressed in total chlorides are evaluated to use in many studies In this study, the capacity of chloride binding in cement matrix was monitored for 150 days and then quantified using the Langmuir isotherm to determine the portions of free chlorides and bound chlorides at given total chlorides and the redistribution of free chlorides. Then, the diffusion of chloride ion in concrete was modeled by considering the binding capacity for the prediction of chloride profiles with the redistribution. The predicted chloride profiles were compared to those obtained from conventional model. It was found that the prediction of chloride profiles obtained by the model has shown slower diffusion than those by the conventional ones. This reflects that the prediction by total chloride may overestimate the ingress of chlorides by neglecting the redistribution of free chlorides caused by the binding capacity of cement matrix. From the evaluation, it is also shown that the service life prediction using the free chloride redistribution model needs different expression for the chloride threshold level which is expressed by the total chlorides in the conventional diffusion model.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.307-312
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• 2003

Antioxidative activities of Methanol and Ethanol extract of branch, bark, leaves, fruits, wood of Hovenia dulcis THUNBER var. koreana Nakai were analyzed for total poly phenol, flavonoid, antioxidant capacity and DPPH free radical scavanging activitiy. The most total polyphenol and flavonoid contents measerd extract from bark and fruits. Extract from fruits and bark show hight on antioxidant capacity and DPPH free radical scavanging activitiy. There was a good correlation between total polyphenol or flavonoid contents and antioxidant activity.

• Research in Mathematical Education
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• v.18 no.4
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• pp.273-288
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• 2014

In recent years, coding education has been globally emphasized and the Free Semester System will be executed to the public schools in Korea from 2016. With the introduction of the Free Semester System and the rising demand of Computational Thinking (CT) capacity, this research aims to design 'learning environment' in which learners can design and construct mathematical objects through computers and print them out through 3D printers. Furthermore, it will design learning mathematics by constructing the figurate number patterns from 'soma cubes' in the playing context and connecting those to algebraic and combinatorial patterns, which will allow students to experience mathematical connectivity. It is expected that the activities of designing figurate number patterns suggested in this research will not only strengthen CT capacity in relation to mathematical thinking but also serve as a meaningful program for the Free Semester System in terms of career experience as 3D printers can be widely used.

• Tribology and Lubricants
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• v.31 no.4
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• pp.141-147
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• 2015

Gas foil thrust bearings (GFTBs) have attractive advantages over rolling element bearings and oil film thrust bearings, such as oil-free operation, high speed stability, and high-temperature operation. However, GFTBs have lower load carrying capacity than the other two types of bearings owing to the inherent low gas viscosity. The load carrying capacity of GFTBs depends mainly on the compliance of the foil structure and the formed hydrodynamic wedge, where the gas pressure field is generated between the top foil and the thrust runner. The load carrying capacity of the GFTBs is very important for the suitable design of oil-free turbomachinery with high performance. The aim of the present study is to identify the characteristics of the load carrying performance of GFTBs. A new test rig for the experimental measurements is designed to provide static loads up to 800 N using a pneumatic cylinder. The maximum operating speed of the driving motor is 30,000 rpm. A series of experimental tests—lift-off test, static load performance test, and maximum load capacity test—estimate the performance of a six-pad GFTB, in terms of the static load, driving torque, and temperature. The maximum load capacity is determined by increasing the static load until the driving torque rises suddenly with a sharp peak. The test results show that the torque and temperature increase linearly with the static load. The estimated maximum load capacity per unit area is approximately 80.5 kPa at a rotor speed of 25,000 rpm. The test results can be used as a design guideline for GFTBs for realizing oil-free turbomachinery.