• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.385-395
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• 2020

This study examined the effect of 3,4-dihydroxytoluene (DHT) on UVB-induced photoaging and determined its molecular mechanisms, using HaCaT human keratinocytes and SKH-1 hairless mice. DHT suppressed UVB-induced matrix metalloproteinase-1 (MMP-1) expression in HaCaT cells. In vivo data from mouse skin supported that DHT decreased UVB-induced wrinkle formation, epidermal thickness, and matrix metalloproteinase-13 (MMP-13) expression. DHT appeared to exert its anti-aging effects by suppressing UVB-induced Raf-1 kinase activity and subsequent attenuation of UVB-induced phosphorylation of MEK, ERK, and p90RSK in HaCaT cells. In vitro and in vivo pull-down assays revealed that DHT bound with Raf-1 in ATP-noncompetitive manner. Overall, DHT appears to anti-photoaging effects in vitro and in vivo through the suppression of Raf-1 kinase activity and may have potential as a treatment for the prevention of skin aging.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1573-1580
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• 2006

In this study, fatigue tests were carried out under push-pull loading condition using spheroidal graphite cast iron in order to clarify the internal fatigue fracture mechanism in an extremely low cycle fatigue regime. It is found that a successive observation of internal fatigue damage it is found that the fracture processes go through three stages, that is, the generation, growth and coalescence of microvoids originated from debonding of graphite-matrix interface. It is also found that the crack which is initiated from the void propagates by coalescence of neighboring cracks and the fatigue crack growth rate can be expressed in form of the Manson-Coffin rule type. In this paper, quantitative analyses of fatigue properties for realization of simulation about fatigue life evaluation are also presented.

• Journal of the Korean Society for information Management
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• v.11 no.2
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• pp.67-87
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• 1994

On the demand and real state of the regional information had been studied and surveyed especially in the area of Kwang Ju and Chonnam Province. Revealed the information minds and skills of Kwangju area lower compared with any other regions. The research finally proposed the methods to pull up the information minds and skills through the education and the supplies of the communication equipments.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.166-175
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• 1999

This paper describes a design and performance evaluation of robust controller which overrides unstable motion and pulls out quickly after water entry of underwater vehicle dropped from aircraft or surface ship. We use 6-DOF equation for model of motions and assume parameter uncertainty to reflect the difference of real motion from modelled motion equation. we represent a nonlinear system with uncertainty as Takagi and Sugeno's(T-S) fuzzy models and design controller stabilizing them. The fuzzy controller utilizes the concept of so-called parallel distributed compensation (PDC). Finally, we confirm stability and performance of the controller through computer simulation and hardware in the loop simulation (HILS).

• Journal of the korean Society of Automotive Engineers
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• v.10 no.3
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• pp.51-59
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• 1988

The wake structure behind a van type vehicle was studied experimentally with a 5-hole yawhead probe. Through an effective calibration method of the 5-hole yawhead probe, the flow properties such as velocity vector, total pressure and static pressure were obtained on two cross sections within the wake. These results combined with the surface flow visualization performed in the previous study, yielded some information about the wake structure. When the model was placed in a stream with zero yaw angle, two counter rotating vortices were observed behind the model which pull down the surface flow on each side of the model. With increasing the yaw angle, the surface flow on the windward side changed to divide the flow in two directions, one flows upward on the upper part and the other flows downward on the lower part of the windward side. Hence a new weak vortex was created on the upper windward side, which resulted 3 vortices within the wake. The size and the strength of the vortices increased with yaw angle.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.95-96
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• 2016

The floor slip test method using O-Y·PSM was developed based on the risk assessment and sense of slip by the users implementing actions such as changing walking direction on a floor. This test method is regulated under the Korea Industrial Standard KS M 3510, and in the Korea Industrial Standard KS F 3230, the article of KS M 3510 is cited. Yet, in the standard, the surface condition of test or slip adjustment method is merely mentioned or difficult to be found, and thus it creates confusion in floor slip test using O-Y·PSM. Therefore, this study is to provide the useful data to revise the relative standard through the standardization study including various surface conditions of sample and slip adjustment method used in floor slip test method using O-Y·PSM.

• Advances in pediatric surgery
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• v.8 no.1
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• pp.64-67
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• 2002

Since Swenson and Bill established the treatment principles of Hirshsprung's disease in 1948, there have been significant advances in the management of this disease. During the last decade, one-stage correction of Hirshsprung's disease without colostomy and primary laparoscopic pull-through procedure became popular with recent advances in the technology and refinement of the equipments. But the outcomes for Hirshsprung's disease are not always successful, and long-term follow-up isessential. Most children after corrective surgery show significant improvement in respect to fecal continence and constipation, that may not be apparent until late adolescence. The purpose of this study was to review the postoperative problems of Hirschsprung's disease and it's management.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.3
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• pp.183-189
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• 2005

A modeling of a hydraulic-gun-aerator is proposed to set up a design procedure for such devices. The aerators are used to destroy any thermal stratification that are responsible for the degradation of water qualify of lakes. The aerator produces ascending flow by using air bubbies released instantly near the bottom of the lake into a cylindrical pipe installed vertically. Differently form the diffuser-aerators, they can pull up the cold, oxygen depleted water directly to the region of the free surface, and they are believed to work effectively especially for relatively deeper lakes. Their design procedure has not been established yet though, and we propose a model focusing on the exit flow velocity at the top of the aerator through the examination of presently operating devices.

• Journal of architectural history
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• v.14 no.4 s.44
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• pp.29-39
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• 2005

The Honam region has played an important role in the development of Korea poetry. So this study focuses on Song Soon among various factors of Honam architecture in 16th century. He was ahead of his times in development of Korean literature, and made buildings that become background and materials of his literature. Song Soon built Myonang-jong in Damyang for his life time and tried to design to pull in nature into his buildings. These buildings were built in beautiful landscape, and showed elegance as a retired scholar and Taoism characteristics. He provided basic ideas, that is, pulling in nature into architecture, and metaphysics morality, and his ideas also influenced Honam School Including Jung Chul. This study looks into Nujung architecture that had become materials of Myonang-jong Song Soon literature and characteristics of Honam architecture through his buildings at the same time.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.219-224
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• 2009

In this study, the characteristics of pullout behavior of Pressurized light-weight steel Anchor was investigated through centrifuge model tests considering pull-out angle $0^{\circ}$ with changing undrained shearstrength(0~1, 2~4, 5~7kPa) of clay. According to the results of tests, the yield pullout load of clay ground was gradually increased up to 30% as undrained shear strength was increased. Therefore, it was known that the yield pullout load was affected by increasing the undrained shear strength, in addition, the pattern of behavior was not changed.