• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.137-144
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• 2010

Up to now, common studies of top base have concentrated upon bearing capacity and settlement by in-situ loading test in Japan and Korea. But most of all preceding study for top base must analyze how to deliver overburden loading on bottom of foundation. Therefore, in this study, the stress delivery mechanism of Top-Base Foundation developed in Japan and Floating Top Base developed in Korea is investigated through numerical analysis and laboratory model test. Analyzing the load delivery mechanism of top base, it was found that the division rate of load reduction of top base for overburden load was largest in peripheral skin friction between the top base and the crushed stone. Further, total stress dispersion angle of Top-Base Foundation including internal stress dispersion effect of top base was $41.8^{\circ}$ and total stress dispersion angle of Floating Top Base was $44.5^{\circ}$.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.275-281
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• 2014

In this study, accelerated weathering test was performed with wood, a major material for wooden cultural building. In order to evaluate the deterioration of wood, ultrasonic transmission times were measured to evaluate dynamic modulus of elasticity (MOE), which was verified by determining static MOE using three-point bending test. Ultrasonic transmission time was decreased with an increase in the weathering time levels (0, 500, 1000 hours) while it increased in 1500 and 2000 hours. Distribution of dynamic and static MOE was similar to that of the ultrasonic transmission time measurements. The results mean that the measurement of ultrasonic transmission time was very effective to evaluate MOE of wooden cultural buildings for their preservation and management. This method could be utilized to assess wooden cultural buildings as a way of preserving them in a scientific manner.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.109-120
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• 2003

The state-of-art of curved box girder bridge with cross section design has advanced in various area. In these days, several analytical techniques for behaviors of curved box girder bridges cross section are available to engineers. The transfer matrix method is extensively used for the structural analysis because its merit in the theoretical background and applicability. The technique is attractive for implementation on a numerical solution by means of a computer program coded in Fortran language with a few elements. To demonstrate this fact, it gives good results which compare well with finite element method. Therefore, this paper proposed the static analysis method of curved box bridge with cross section by transfer matrix method based on pure-torsional theory and the optimal span ratio/variable cross section ratio of 3 span continuous curved box girder bridge.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.91-91
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• 2004

유압시스템은 1795년 J. Bramah가 물을 작동유체로 사용한 Press를 개발해 사용한 이래 2세기 이상 인간생활의 다양한 분야에 이용되어 왔다. 초기 유압시스템은 쉽게 구할 수 있고, 저장이 용이한 물을 작동유체로 사용하였다. 그러나 물은 부식성, 낮은 점성계수로 인한 저 윤활성과 많은 누설량, 그리고 저온에서의 동결 등과 같은 문제점을 가졌다. 당시에는 물에 대한 부식성이 없는 재료나 물의 누설을 막을 수 있을 만큼의 가공기술이 부족하였으므로 이러한 물의 문제점을 해결하기 위해 1906년 Wiliams와 Janney가 물 대신 기름을 작동유체로 사용하기 시작했다.(중략)

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.428-435
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• 2020

In this study, we evaluated the inhibitory effect against cell growth and potential molecular mechanism of 100% ethanol extracts of branch from Sageretia thea in human colorectal cancer cells, HCT116. Ethanol dose-dependently extracts of STB significantly suppressed the growth of HCT116 cells through apoptosis. STB activated NF-κB signaling pathway through IκB-α proteasomal degradation and inducing p65 accumulation in nucleus. The inhibition of GSK3β by LiCl didn't affect STB mediated degradation IκB-α but STB mediated p65 accumulation in nucleus. In addition, STB phosphorylated GSK3β. Based on these findings, STB may be a potential candidate for the development of anti-cancer agents for human colorectal cancer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.133-141
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• 1995

The effects of allelochemicals from medicinal plants have been studied as photo-synthetic inhibitor for photoautotrophic(PA) cultured cells. The extracts from 9 plant species were used for measuring the physiological effects on the liverwort cultured cell in following areas; germination inhibition, chlorophyll contents, hill activity, cell viability, photosynthetic oxygen evolution,and protein pattern changes on SDS PAGE. Germination inhibitions were detected in all plant after treating with 10% extract. Especially, treatment with 10% extract from Pulsatilla koreana and Aconitum carmichael inhibited germinations completely. Chlorophyll fornation was inhibited completely by treating PA cells with extract of Pulsatilla koreana, whose effect was similar to that of DCMU 10-3M, inhibitor for photosynthetic electron trans-fer. The treatment with extract from Pulsatilla koreana on PA cell showed the highest hill activity and the lowest cell viability among extracts studied. Oxygen releasing has been decreased down to 14-77% after treating with extracts from Pinellia ternata, Araliacont inentaila, Pulsatilla koreana and Vitex rotundifolia. Especially, 60$\mu$l of Pulsatilla koreana extract into 2ml mixture of PA cell inhibit-ed oxygen release up to 50%. Protein bands on SDS-PAGE, 14kD, 31kD, 41kD, 53kD, and 73kD, were not detected after treating Pulsatilla koreana extract on PA cells.

• Analytical Science and Technology
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• v.13 no.5
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• pp.630-635
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• 2000

The concentration of neurotransmitters in rat brain was determined by HPLC-ECD (electrochemical detection) method and the effects of methanol extracts of some crude drugs, such as Polygala Radix, Myristicae Semen, Zizyphi Semen, Acori graminei Rhizoma, Visci Herba, Liriopsis Tuber, Myrrha on the concentration of neurotransmitters in the ethanol-treated rat brain were investigated. By the administration of ethanol, dopamine (DA), 3, 4-dihydroxyphenyl acetic acid (DOPAC) and serotonin (5-HT) levels in frontal cortex and 5-HT level in hippocampus were significantly increased compared with the neurotransmitter levels in the brain of saline-treated rats. The ${\gamma}$-aminobutyric acid (GABA) level in frontal cortex was decreased by the same treatment. There was a tendency that the DA level in frontal cortex and striatum of ethanol-treated rats were increased by the administration of crude drug extracts. Especially, Myrrha and Visci Herba significantly increased the DA level of frontal cortex in ethanol-treated rats, while they significantly decreased the 5-HT level in the same region of the brain. GABA level in striatum of ethanol-treated rats was significantly decreased by Myristicae Semen, Visci Herba and Myrrha. These results suggest that the tested crude drug extracts have selective interaction with neurotransmitters in specified region of central nervous system.

• Economic and Environmental Geology
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• v.56 no.1
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• pp.13-21
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• 2023

X-ray powder diffraction study was conducted on the bulk modulus and phase transition behavior of synthetic zeolite X under high temperature and high pressure. Water and HCO₃^- solution were used as a PTM. Sample was heated and pressurized up to 250 ℃ and 5.18 GPa. The change of unit cell volume and phase transition were observed by X-ray diffraction. The lattice constants and unit cell volume of zeolite X, gmelinite, natrolite, and smectite were calculated using the GSAS2 program to which Le Bail's whole powder pattern decomposition (WPPD) method was applied. The bulk modulus of each zeolite X and smectite were calculated using the EosFit program to which the Birch-Murnaghan equation was applied. The bulk modulus of zeolite X is 89(3) GPa in water run, and zeolite X is 92(3) GPa in HCO₃^- solution run. In both run, pressure induced hydration (PIH) occurred due to the inflow of PTM into the zeolite X framework at initial pressure. Zeolite X transited to gmelinite, natrolite, and smectite in water run. Zeolite X, however, transited to smectite in HCO₃^- solution run. Interzeolite transformation occurred in water run, and did not occur in HCO₃^- solution run, which is assumed that conflict between the environment to form zeolite and the pH of the HCO₃^- solution.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.37-38
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• 2009

In this paper, the load transfer test of Korean PS anchorage system was conducted for 1860MPa PS strand and 2200MPa PS strand. The test is in compliance with ETAG013. All the anchorage system tested satisfied the allowance criteria of the test for 1860MPa PS strand but only one of the anchorage systems for 2200MPa PS strand. In order to generally use 2200MPa PS strand to prestressed concrete structures, new anchorage systems shall be developed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.1
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• pp.16-22
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• 2001

In this study for reduction degree of freedom of dynamic model, a mixed method to combined finite element method and transfer matrix method is presented. This offers the advantages of an automatic reduction in the size of the eigenvalues problem and of a straightforward means of dynamic substructuring. The analytical procedure in this method for dynamic analysis of 3-dimensional cantilevered box beam are described. the result of numerical example is shown to demonstate the efficiency and accuracy of this method. The result form this example agree well those obtained by ANSYS, By using this technique, the number of nodes required in the regular finite element method is reduced and therefore a smaller com-puter can be used.