• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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• pp.158-162
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• 2010

PSD is automatically opened and closed when subway train arrive on the station. This system was designed to control electric automatic system. These doors will provide passenger safety, energy saving and a good environment in subway. The monitoring and control systems of PSD are configured so that they can be operated in automatic mode in connection with ATO through the composite control panel in the station control room. The objective of this paper is to obtain high reliability that is essential for monitoring and control systems of PSD. The power supply is based on protection circuit using DC power bridge from two UPS. Also, stable communication system consists of CAN communication line redundancy and RF cross protection algorithm. Monitoring state display results show the validity of the proposed high reliability monitoring and control systems of PSD.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.169-177
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• 1997

An experimental study has been conducted at an intermediate scale to study the effect of a cross flow on a purely buoyant fire. Video taping of the flame and post processing of the images by means of a novel technique provide a contour of a mean flame for all cases studied. This flame contour allows the determination of a mean flame length and a mean flame height. The mean flame length and height are recorded as functions of the forced flow velocity. Three dimensional flow patterns are formed in the flame trailing edge affecting both the mean flame length and height. The three dimensional patterns are studied systematically as functions of the cross flow velocity to quantify the effect of confinement on the flame geometry.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.759-770
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• 1985

This study was experimentally undertaken to evaluate the effect of hypothermic oxygenated cardioplegic solution on myocardial protection during prolonged aortic cross clamping under cardiopulmonary bypass. Dogs were divided into two groups control group [received hypothermic unoxygenated cardioplegic solution] and experimental group [received hypothermic oxygenated cardioplegic solution]. Coronary sinus effluent was obtained at once and 30, 60, 90 minutes after cross-clamping for the determination of pH, PCO2,PO2 and lactate level during the infusion of cardioplegic solution and myocardial biopsies were obtained after cessation of 90 minutes of aortic cross-clamping. The results obtained were as follows: 1. There was no significant differences in the pH and PCO2 between the oxygenated and unoxygenated cardioplegic solution but the PO2 of the oxygenated solution was 4 times greater than unoxygenated solution, and also the oxygenated solution had a significantly greater oxygen content [2.020.05 ml 02/min] and had much more oxygen delivery than unoxygenated solution. 2. The myocardial oxygen consumption and the myocardial oxygen extraction in oxygenated group were 1.63 ml 02/100 ml and 67.32% respectively, which was greater than those in unoxygenated group. 3. Regarding to pH and PCO2 of coronary sinus effluent, there was no significant differences between two groups in early period of infusion of cardioplegic solution, but the pH shifted to acidosis from 60 minutes, PCO2 increased from 90 minutes of aortic cross-clamping, and PO2 markedly decreased from 90 minutes of aortic cross-clamping in unoxygenated group. 4. The lactate concentration of coronary sinus effluent revealed relatively normal in both groups, but showed slight increase up to 27.54.56 mg/100 ml at 90 minutes of aortic cross-clamping in unoxygenated group. 5. On electron microscopic study, the ultrastructural integrity of myocardial cells in oxygenated group was well preserved within 90 minutes. Slight swelling and deformity of mitochondria, interfibrillar widening, and disarrangement of myofibrils were observed at 90 minutes after aortic cross-clamping in unoxygenated group. From these results, the use of hypothermic oxygenated cardioplegic solution seemed to be effective and better method for the preservation of ischemic myocardium during the prolonged aortic cross-clamping.

• Journal of Distribution Science
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• v.21 no.10
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• pp.1-9
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• 2023

Purpose: This study analyses the current development of cross-border e-commerce in China, outlines the challenges faced by Chinese cross-border e-commerce SMEs, and finally summarises the development strategies of Chinese cross-border e-commerce SMEs in the post-covid-19 era, which will provide opinion references for the development of Chinese cross-border e-commerce SMEs. Research design, data and methodology: The methodology used in this study is to analyse the current situation of cross-border e-commerce development in China in the context of covid-19 through literature; and to summarise the challenges encountered by Chinese cross-border e-commerce SMEs through semi-structured interviews. Results: The article summarises the current status of China's cross-border e-commerce development in the context of covid-19 in terms of cross-border e-commerce trade volume, cross-border e-commerce enterprise and user scale, cross-border e-commerce logistics, cross-border e-commerce global co-operation, government policy, and cross-border e-commerce product distribution, outlining challenges encountered by China's cross-border e-commerce SMEs in terms of logistic pricing, operating capital chain, product service support, and trade protection The paper Finally, it is pointed out that Chinese cross-border e-commerce SMEs must adopt new strategies to adapt to the new development in the context of covid-19. Conclusions: Specific development strategies are provided for Chinese cross-border e-commerce enterprises and reference suggestions are provided for the post-covid-19 era.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.169.2-169.2
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• 2010

Recently, the massive offshore bridges in a ship passage have been constructed on the sea. Therefore, the ship impact protection for the bridge-piers are installed to consider the possibility of vessel collision danger. Due to the ship impact protection, the flow-field characteristics are changed in comparison with the condition without the ship impact protection. Especially, the fluid velocity between the pier and the ship impact protection is possible to increase due to the contraction of the cross sectional area of flow. In this study, the tidal energy magnitude around the ship impact protection of Incheon bridge is assessed by simulating the flow-field by using FLOW-3D software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.7
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• pp.398-400
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• 2014

In this letter, we propose a cross-layer technique jointly considering modulation coding schemes (MCSs) of medium access control (MAC) layer, source significance information (SSI) and error concealment unit of application (APP) layer, and channel quality information (CQI) of physical (PHY) layer. We demonstrate the improved video quality by the proposed technique when H.264 videos are streamed over Rayleigh fading wireless channels.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.228-235
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• 2021

Backgroud: Ginsenoside compound K (GK) is a major metabolite of protopanaxadiol-type ginsenosides and has remarkable anticancer activities in vitro and in vivo. This work used an ionic cross-linking method to entrap GK within O-carboxymethyl chitosan (OCMC) nanoparticles (Nps) to form GK-loaded OCMC Nps (GK-OCMC Nps), which enhance the aqueous solubility and stability of GK. Methods: The GK-OCMC Nps were characterized using several physicochemical techniques, including x-ray diffraction, transmission electron microscopy, zeta potential analysis, and particle size analysis via dynamic light scattering. GK was released from GK-OCMC Nps and was conducted using the dialysis bag diffusion method. The effects of GK and GK-OCMC Nps on PC3 cell viability were measured by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Fluorescent technology based on Cy5.5-labeled probes was used to explore the cellular uptake of GK-OCMC Nps. Results: The GK-OCMC NPs had a suitable particle size and zeta potential; they were spherical with good dispersion. In vitro drug release from GK-OCMC NPs was pH dependent. Moreover, the in vitro cytotoxicity study and cellular uptake assays indicated that the GK-OCMC Nps significantly enhanced the cytotoxicity and cellular uptake of GK toward the PC3 cells. GK-OCMC Nps also significantly promoted the activities of both caspase-3 and caspase-9. Conclusion: GK-OCMC Nps are potential nanocarriers for delivering hydrophobic drugs, thereby enhancing water solubility and permeability and improving the antiproliferative effects of GK.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.304-316
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• 2021

Vaccination is the most effective way to prevent influenza virus infections. However, conventional vaccines based on hemagglutinin (HA) have to be annually updated because the HA of influenza viruses constantly mutates. In this study, we produced a 3M2e-3HA2-NP chimeric protein as a vaccine antigen candidate using an Escherichia coli expression system. The vaccination of chimeric protein (15 ㎍) conferred complete protection against A/Puerto Rico/8/1934 (H1N1; PR8) in mice. It strongly induced influenza virus-specific antibody responses, cytotoxic T lymphocyte activity, and antibody-dependent cellular cytotoxicity. To spare the dose and enhance the cross-reactivity of the chimeric, we used a complex of poly-γ-glutamic acid and alum (PGA/alum) as an adjuvant. PGA/alum-adjuvanted, low-dose chimeric protein (1 or 5 ㎍) exhibited higher cross-protective effects against influenza A viruses (PR8, CA04, and H3N2) compared with those of chimeric alone or alum-adjuvanted proteins in vaccinated mice. Moreover, the depletion of CD4+ T, CD8+ T, and NK cells reduced the survival rate and efficacy of the PGA/alum-adjuvanted chimeric protein. Collectively, the vaccination of PGA/alum-adjuvanted chimeric protein induced strong protection efficacy against homologous and heterologous influenza viruses in mice, which suggests that it may be a promising universal influenza vaccine candidate.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.182-194
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• 2022

Objectives: This study evaluates and recommends the priority of policy implementation to improve the fire protection clothing management system used by firefighters and the reduction of cross-contamination from contaminated clothing at the scene of a fire. Methods: It consisted of 7 experts and conducted three interviews and two modified Delphi surveys. Through the results of previous research and interviews with experts, a plan to reduce cross-contamination of fire suits and improve the management system was first derived. An improvement plan was presented in the four areas including resources, management, fire protection related work, and laws and regulations, and the priority of policy implementation was derived by analyzing the importance and practicality of the policy at the same time. Results: As a result of the analysis, the first priority was education on the health effects of pollutants at the disaster scene for firefighters, and the second priority was the addition of SOP for the primary decontamination of on-scene personal protective equipment in preparation for the health effects of the disaster scene, and education for fire suppression and rescue workers. The next step was to improve the management system of personal protective equipment such as fire suits and develop a training course for systematic operation. Conclusions: This findings could be used in the implementation of mid- to long-term firefighting policies for the systematic operation and establishment of a systematic management system for personal protective equipment such as fire protective suits.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1278-1292
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• 2018

Inductive power transfer (IPT) technology allows for charging of electric vehicles with security, convenience and efficiency. However, the IPT system performance is mainly affected by the magnetic coupling structure which is largely determined by the coupling coefficient. In order to get this applied to electric vehicle charging systems, the power pads should be able to transmit stronger power and be able to better sustain various forms of deviations in terms of vertical, horizontal direction and center rotation. Thus, a novel cross-shaped magnetic coupling structure for IPT charging systems is proposed. Then an optimal cross-shaped magnetic coupling structure by 3-D finite-element analysis software is obtained. At marking locations with average parking capacity and no electronic device support, a prototype of a 720*720mm cross-shaped pad is made to transmit 5kW power at a 200mm air gap, providing a $1.54m^2$ full-power free charging zone. Finally, the leakage magnetic flux density is measured. It indicates that the proposed cross-shaped pad can meet the requirements of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).