• Proceedings of the KSR Conference
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• 2008.11b
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• pp.358-363
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• 2008

Through this study, 2D multibody dynamics models for analysis of train collisions have been developed to evaluate the crashworthiness requirements of the TSI regulation. The crashworthiness regulation requires some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 kph, and a collision against a standard deformable obstacle of 15 ton at 110 kph. The complete train set will be composed of hybrid model with 2D and 1D model. Using numerical analysis of the hybrid model, some crashworthy design were evaluated in terms of mean crush forces and energy absorptions for main crushable structures and devices. especially, 2D model can evaluate overriding effect in train collisions. It is shown from the simulation results that the suggested hybrid model can easily evaluate the crashworthiness requirements.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.1031-1040
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• 1995

Recently, a more strict regulation has become effective on ground vibration and noise induced by construction activities. Consequently the demand for the most widely used method of installing precast piles, i.e. driven piles, is declining. At the same time the demand for low noise and low vibration piling method increased sharply. Currently there are several different low noise and low vibration methods of installing precast piles, mostly preboring method. However, the actual level of ground vibration and noise of these method of construction has not yet been clearly understood. In this paper, through field measurement, suggestion has been made to meet the requirements of the revised regulation.

• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.35-43
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• 2004

The purpose of this study is an economic analysis of power plant utilities by comparing electricity generating cost including environmental costs. Considering the enormous role of electricity in the national economy, it is very important to study the effect of environmental regulation on the electricity sector. Because power utilities need for large investment during construction, operation and maintenance, and also require much construction lead time. Economic analysis is the important process in the electric system expansion planning. This paper compares the costs of electricity generation including environmental costs between a coal-fired power plant and an LNG combined cycle power plants. With the simulation, this study surveys the sensitivity of fuel prices, interest rate and carbon tax. In each case, this sensitivity can help to decide which utility is economically better in environmental regulation circumstance.

• Journal of Yeungnam Medical Science
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• v.38 no.3
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• pp.183-193
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• 2021

Since its discovery in 1780, lactate has long been misunderstood as a waste by-product of anaerobic glycolysis with multiple deleterious effects. Owing to the lactate shuttle concept introduced in the early 1980s, a paradigm shift began to occur. Increasing evidence indicates that lactate is a coordinator of whole-body metabolism. Lactate is not only a readily accessible fuel that is shuttled throughout the body but also a metabolic buffer that bridges glycolysis and oxidative phosphorylation between cells and intracellular compartments. Lactate also acts as a multifunctional signaling molecule through receptors expressed in various cells and tissues, resulting in diverse biological consequences including decreased lipolysis, immune regulation, anti-inflammation, wound healing, and enhanced exercise performance in association with the gut microbiome. Furthermore, lactate contributes to epigenetic gene regulation by lactylating lysine residues of histones, accounting for its key role in immune modulation and maintenance of homeostasis.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.967-977
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• 2021

From January 1, 2020, the International Maritime Organization has implemented a global regulation, known as IMO 2020, to reduce the sulfur content in fuel oil of ships from 3.5% to 0.5%. In this study, we used data from air monitoring stations to evaluate the change in air quality at New Port and North Port in Korea areas after the regulation was implemented. The concentration of SO₂ and NO₂ was higher in the port areas than in the surrounding areas due to exhaust gas from ships and vehicles. However, the SO₂ concentration decreased by more than 50% in the port area, demonstrating the efficiency and positive effect of the IMO 2020 sulfur limit.

• Journal of Wind Energy
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• v.14 no.1
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• pp.44-51
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• 2023

Some controllers have been introduced in various studies to mitigate the negative effects of renewable sources. These have been modified to fit a formed solution in various ways. This paper deals with the voltage regulation of wind farms in voltage dip situations where communication failures occur. The aim is to discuss the modification of the online wind farm management system. To discuss modifications of the online wind farm management system, we focus on voltage regulation of wind farms when communication failures occur. The structure has been designed to respond to a voltage drop when the outer reference is absent due to communication errors. Since the loss reduction effect has been maintained in the designed case studies, it can be derived that the proposed method can respond to voltage drops, along with a used objective function.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.15-18
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• 2007

This study investigated disinfection effect by general water purifier and water purifier with UV light disinfection. The results are as follows : (i) The general bacteria existed plentifully in a storage tank before treatment (ii) Water treated in water purifier did not meet the water treatment regulation standard since the presence of bacteria, whereas with UV light application the regulation standard is totally satisfied. (iii) Photocatalytic disinfection process with UV light in the presence of $TiO_2$ more effectively killed general bacteria than UV light only.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.343-351
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• 2016

The purpose of this study was to evaluate the whitening effect of aerial part of Pueraria lobata and mechanisms. Aerial part of Pueraria lobata, dose-dependently reduced the melanin content. Aerial part of Pueraria lobata, significantly decreased cellular tyrosinase activity, while there was not any effect on tyrosinase in cell-free conditions. To elucidate the mechanisms behind the aerial part of Pueraria lobata, treated melanogenesis regulation, the expressions of melanogensis related genes, proteins, and the activity of ${\alpha}-glucosidase$ were determined. Aerial part of Pueraria lobata, significantly inhibited gene and protein levels of MITF, tyrosinase and TRP-1. It suppressed the ${\alpha}-glucosidase$, leading to inhibition on the maturation of tyrosinase. Also aerial part of Pueraria lobata, was observed to have the high antioxidant activity. These results suggested that whitening effect of aerial part of Pueraria lobata, should be due to the down-regulation of MITF, tyrosinase and TRP-1 expression and the intercepting maturation of tyrosinase through suppressing ${\alpha}-glucosidase$. Another should be the high anti-oxidant activity. The findings show the possibility that aerial part of Pueraria lobata, can be used as a potential skin-whitening agent.

• Journal of Ginseng Research
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• v.47 no.2
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• pp.218-227
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• 2023

Background: Myocardial fibrosis (MF) is an advanced pathological manifestation of many cardiovascular diseases, which can induce heart failure and malignant arrhythmias. However, the current treatment of MF lacks specific drugs. Ginsenoside Re has anti-MF effect in rat, but its mechanism is still not clear. Therefore, we investigated the anti-MF effect of ginsenoside Re by constructing mouse acute myocardial infarction (AMI) model and AngII induced cardiac fibroblasts (CFs) model. Methods: The anti-MF effect of miR-489 was investigated by transfection of miR-489 mimic and inhibitor in CFs. Effect of ginsenoside Re on MF and its related mechanisms were investigated by ultrasonographic, ELISA, histopathologic staining, transwell test, immunofluorescence, Western blot and qPCR in the mouse model of AMI and the AngII-induced CFs model. Results: MiR-489 decreased the expression of α-SMA, collagenI, collagen III and myd88, and inhibited the phosphorylation of NF-κB p65 in normal CFs and CFs treated with AngII. Ginsenoside Re could improve cardiac function, inhibit collagen deposition and CFs migration, promote the transcription of miR-489, and reduce the expression of myd88 and the phosphorylation of NF-κB p65. Conclusion: MiR-489 can effectively inhibit the pathological process of MF, and the mechanism is at least partly related to the regulation of myd88/NF-κB pathway. Ginsenoside Re can ameliorate AMI and AngII induced MF, and the mechanism is at least partially related to the regulation of miR-489/myd88/NF-κB signaling pathway. Therefore, miR-489 may be a potential target of anti-MF and ginsenoside Re may be an effective drug for the treatment of MF.

• BMB Reports
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• v.51 no.8
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• pp.388-393
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• 2018

The activating transcription factor (ATF) 4 belongs to the ATF/CREB (cAMP Response Element Binding bZIP [Basic Leucine Zipper]) transcription factor family, and plays a central role in the UPR (Unfolded Protein Response) process in cells. The induction of ATF4 expression has previously been shown to increase the replication of HIV-1. However, the detailed mechanism underlying this effect and the factors involved in the regulation of ATF4 function are still unknown. Here, we demonstrate first that knocking out ATF4 using siRNA shows a strong negative effect on HIV-1 production, indicating that ATF4 is a functional positive cellular factor in HIV-1 production. To determine the mechanism by which ATF4 regulates the HIV-1 life cycle, we assessed the effect of the overexpression of wild type ATF4 and its various derivatives on HIV-1 LTR-mediated transcriptional activation and the production of HIV-1 particles. This effect was studied through co-transfection experiments with either reporter vectors or proviral DNA. We found that the N-terminal domains of ATF4 are involved in HIV-1 LTR-mediated transcriptional activation, and thus in HIV-1 production.