• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.3
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• pp.237-245
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• 2012

Coumestrol is one of phytoalexins synthesized in response to environmental stress, and commonly found in natural foods such as alfalfa sprouts, clovers, and soybean. In the present study, we investigated the mechanism underlying protective effect of coumestrol against UVB-induced photoaging in human dermal fibroblasts. We found that pretreatment with coumestrol enhanced the UVB-suppressed mitochondrial biogenesis through regulation of Sirt1 expression and activity, and its downstream gene regulation such as PGC-$1{\alpha}$, NRF1, and TFAM. Moreover, the ATP and ROS production was restored to normal status and the formation of advanced glycation endproducts leading to skin photoaging in skin fibroblasts was blocked by coumestrol pretreatment before UVB irradiation. These findings indicate that coumestrol might potentially prevent skin photoaging induced by mitochondrial damage and glycated protein production in dermal fibroblasts.

• Journal of Ginseng Research
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• v.47 no.3
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• pp.385-389
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• 2023

Background: Ginseng has been used as a traditional medicine for treatment of many diseases and for general health maintenance. Previously, we showed that ginseng did not demonstrate estrogenic property in ovariectomized mouse model. However, it is still possible that disruption of steroidogenesis leading to indirect hormonal activity. Methods: The hormonal activities were examined in compliance with OECD guidelines for detecting endocrine disrupting chemicals: test guideline (TG) No. 456 (an in vitro assay method for detecting steroidogenesis property) and TG No. 440 (an in vivo short-term screening method for chemicals with uterotrophic property). Results: Korean Red Ginseng (KRG) and ginsenosides Rb1, Rg1, and Rg3 did not interfere with estrogen and testosterone hormone synthesis as examined in H295 cells according to TG 456. KRG treatment to ovariectomized mice did not show a significant change in uterine weight. In addition, serum estrogen and testosterone levels were not change by KRG intake. Conclusion: These results clearly demonstrate that there is no steroidogenic activity associated with KRG and no disruption of the hypothalamic-pituitary-gonadal axis by KRG. Additional tests will be performed in pursuit of cellular molecular targets of ginseng to manifest mode of action.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.126-132
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• 2012

Recently, pedestrian protection related research topics have been actively studied by automotive designers and engineers due to the enhanced pedestrian protecting regulations. It is required to design an energy absorbing structure, such as crumple zone that can sufficiently absorb the impact energy to reduce the leg injury when accident happens. The structure is designed by reducing the height of front end module, considering the mounting location, and investigating impact characteristics. In this paper, the concept of the crumple zone was introduced and the role of the crumple zone was investigated by analyzing the performance of upper legform impact to a bonnet leading edge test, and the design process was suggested.

• Asia pacific journal of information systems
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• v.12 no.3
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• pp.1-20
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• 2002

For the last decade, some leading groups of corporations in Korea have integrated and managed their Information Systems(IS) functions. Each group established a separate System Management(SM) company to manage the IS and tried to get a synergy effect from the integration. These attempts, however, were not initiated by any one company. Rather they were group efforts. Moreover, the previous measuring tools evaluated IS with the scope of technical performance or quantitative user satisfaction using an absolute scale. Obscure criteria were used in an attempt to present improvements in IS function which were qualitatively weak. This study evaluates whether integration has been efficient and successful. For this purpose, we evaluate the performance efficiency of IS functions with Data Envelopment Analysis(DEA) methodology. In comparison with prior methods, DEA presents the rate of relative efficiency, the efficiency frontier for improving inefficiency, the degree of improvement(slack), and the guideline to construct any benchmark(reference set). For our DEA evaluation, this study selected a leading group of 23 companies in Korea. Our experimental results are as follows. First, efficiency was rated low on average. It also demonstrates that the motivation of performance efficiency of IS functions is deficient. Second, the result of the test to find the existence of economy of scale and scope shows that the growth of an organization and industrial characteristics do not affect IS performance efficiency from the perspective of user satisfaction. Finally, the comparison with other evaluation approaches informs us that DEA can be a complementary evaluation method which supports other measuring tools.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.48-54
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• 2016

In the present work, numerical simulations were conducted on the scaled model of the BWB type UCAV in the subsonic region using ANSYS FLUENT V15. The prediction method was validated through comparison with experimental results and the effect of the twisted wing was investigated. To consider the transitional flow phenomenon, ${\gamma}$ transition model based on SST model was adopted. The coefficients of lift, drag and pitching moment were compared with experimental results and the pressure distribution and streamlines were investigated. The twisted wing decreases the lift force but increases lift-to-drag ratio through delay of stall and leading edge vortex's movement to the front, also the non-linearity of the pitching moment is decreased.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.134-140
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• 2008

Preceding vehicle detection is a crucial issue for driver assistance system as well as for autonomous vehicle guidance function and it has to be performed with high reliability to avoid any potential collision. The vision-based preceded vehicle detection systems are regarded promising for this purpose because they require little infrastructure on a highway. However, the feasibility of these systems in passenger car requires accurate and robust sensing performance. In this paper, an preceded vehicle detection system is developed using stereo vision sensors. This system utilizes feature matching, epipoplar constraint and feature aggregation in order to robustly detect the initial corresponding pairs. After the initial detection, the system executes the tracking algorithm for the preceded vehicles including a leading vehicle. Then, the position parameters of the preceded vehicles or leading vehicles can be obtained. The proposed preceded vehicle detection system is implemented on a passenger car and its performances is verified experimentally.

• KSTLE International Journal
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• v.3 no.1
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• pp.30-37
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• 2002

There have been significant improvements in base oil quality in order to satisfy recent market needs. In particular requirements of passenger car motor oils have been leading the trend. Now, high quality base oils such as VHVI base oils and PAOs are to be formulated in order to meet the tight volatility specifications. The severe hydrocracking, hydro-isomerized dewaxing and hydro-finishing process with noble-metal based catalysts (named UCO lube process) developed by SK corporation has been introduced as one of economic hydroprocessing routes to produce high quality VHVI base oils and food grade white mineral oils from fuels hydrocracker residue. Product quality of UCO lube process is similar to PAO in. general performances and therefore provides satisfactory performance far all straightforward applications in general lubricants. However, when applied to specialty lubricants like transformer oils, spray oils and coning oils, severely hydrocracked base oils are known to have various compatibility problems with gas or surfactants formulated in them. These problems are related to the difference in their composition; inherent high paraffin contents and lack of dissolving ability, Fortunately, it was found that excellent specialty lubricants could be made by carefully selecting and formulating adequate additives and/or aromatic compounds. Moreover, these specialties with high quality VHVI base oils ofter various advantages over conventional base oil based products.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.579-586
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• 2017

The defense industry has become a global industry, and military technology is actively being traded between countries to increase their military capabilities. The Republic of Korea has been ranked one of the top 10 countries for exports of military technology. To maintain competitive advantages in the global defense industry, it is essential to protect key technologies employed by exported weapon systems. Various techniques have been developed for protection of confidential technologies in weapon systems, and the U.S. DoD has been leading the development of the protection techniques. This paper reviews current anti-tampering techniques that prevent leakage of key technology from weapon exportation or pillage. Based on the protection techniques employed by the U.S. DoD Anti-Tamper Executive Agent, this paper suggests novel design methods for protection of confidential technologies. The proposed design methods were tested on an actual weapon system.

• Journal of the Korean Society of Costume
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• v.64 no.2
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• pp.50-69
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• 2014

Sustainability has been a big issue over the whole global industry lately and is an important fashion trend that reflects the modern phase of the time. The concept of sustainable fashion includes physical fashion products made from eco-friendly or recycle materials as well as ethical value such as corporate social responsibility for environment, labor or working condition. Fashion companies of advanced countries who are aware of the geo-environmental and ethical issues found that generating profits by setting trends and pursuing external beauty can no longer be the ultimate goal of fashion companies, and started to recognize the importance of sustainable fashion as a future-oriented trend. Not only fashion industry but also governments of advanced countries have been playing a leading role to educate the people regarding the importance of sustainable fashion and making large investments to foster industry specialists in educational institution. The aim of this study is to propose sustainable fashion design education program that fits the domestic university curriculum and government-leading education program in order to set the foundation for sustainable fashion industry. Thus, this study investigates successful cases of foreign government-led sustainable fashion education that can be introduced to improve domestic sustainable fashion education. The empirical study of the research is developing 12-15 week university level education program to foster specialists in sustainable fashion. The survey carried out by the students who participated in the program shows the change of perception on sustainable fashion. Developed university level program can be spread to municipal corporation, school of continuing education, and etc. in order to derive participation and problem perception of the citizens on sustainability. Developing systemized sustainable fashion design education program would be the first step of sustainable fashion by educating students who will take the leading role in the future fashion industry. Moreover, it can strongly influence future customer education as well as a special education inducing interest on sustainability in everyday life. A follow-up study is expected to serve as a foundation for sustainable fashion to take root successfully in the fashion industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.3
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• pp.50-58
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• 2017

TPCLT(Twice Per Cycle Left-turn) operation reduces this left-turn 'spill-over' problem on an as needed basis by servicing the protected left-turn movement as a leading and a lagging left-turn. In this study, to evaluate the effectiveness of TPCLT applied to three-legged signalized intersection in Korea, the analysis was carried out using VISSIM and SSAM model analysis. The study was implemented by three cases which are TPCLT operation, non-TPCLT operation and half-cycle operation using VISSIM program. According to the 9-left-turn volume scenario, total delay and travel times of each case was analyzed by VISSIM program. The study result shows more effective applying TPCLT operaion in the present ~ +50% scenario area at the intersection in terms of total delay.