• Asian Journal for Public Opinion Research
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• v.9 no.4
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• pp.331-351
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• 2021

The unprecedented situation of COVID-19 caused the government of India to instruct educational institutions to switch to an online mode to mitigate the losses for students due to the pandemic. The present study attempts to explore the impact of online learning introduced as a stop-gap arrangement during the pandemic in India. A survey was conducted (N=289), via Facebook and WhatsApp, June 1-15, 2020 to understand the accessibility and effectiveness of online learning and constraints that students of higher education across the country faced during the peak times of the pandemic. The analysis and interpretation of the data revealed that the students acclimatized in a short span of time to online learning, with only 33.21% saying they were not satisfied with the online learning mode. However, the sudden shift to online education has presented more challenges for the socially and economically marginalized groups, including Scheduled Caste (SC), Scheduled Tribes (ST), Other Backward Class (OBC), females, and students in rural areas, due to factors like the price of high-speed Internet (78.20% identified it as a barrier to online learning), insufficient infrastructure (23.52% needed to share their device frequently or very frequently), poor Internet connectivity, etc. According to 76.47% of respondents, the future of learning will be in "blended mode." A total of 88.92% of the respondents suggested that the government should provide high-quality video conferencing facilities free to students to mitigate the division created by online education in an already divided society.

• Journal of Ginseng Research
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• v.45 no.5
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• pp.610-616
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• 2021

Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for inflammatory responses. Ginsenoside Rg3 (Rg3) which is an active ingredient of Panax ginseng Meyer (Araliaceae) is known to possess various therapeutic effects. However, a modulatory effect of Rg3 on TSLP expression in the inflammatory responses remains poorly understood. Methods: We investigated antiinflammatory effects of Rg3 on an in vitro model using HMC-1 cells stimulated by PMA plus calcium ionophore (PMACI), as well as an in vivo model using PMA-induced mouse ear edema. TSLP and vascular endothelial growth factor (VEGF) levels were detected using enzyme-linked immunosorbent assay or real-time PCR analysis. Murine double minute 2 (MDM2) and hypoxia-inducible factor 1α (HIF1α) expression levels were detected using Western blot analysis. Results: Rg3 treatment restrained the production and mRNA expression levels of TSLP and VEGF in activated HMC-1 cells. Rg3 down-regulated the MDM2 expression level increased by PMACI stimulation. The HIF1α expression level was also reduced by Rg3 in activated HMC-1 cells. In addition, Rg3-administered mice showed the decreased redness and ear thickness in PMA-irritated ear edema. Rg3 inhibited the TSLP and VEGF levels in the serum and ear tissue homogenate. Moreover, the MDM2 and HIF1α expression levels in the ear tissue homogenate were suppressed by Rg3. Conclusion: Taken together, the current study identifies new mechanistic evidence about MDM2/HIF1α pathway in the antiinflammatory effect of Rg3, providing a new effective therapeutic strategy for the treatment of skin inflammatory diseases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.426-432
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• 2021

Injection molding is used in many industrial fields such as home appliances, vehicle parts, and electronic device parts because various resins can be molded, leading to mass production of complex shapes. Generally, the empirical prediction method is used to set the initial processing conditions of injection molding. However, this approach requires a lot of cost and its presented solution is not accurate. In this paper, injection molding was simulated through the Moldflow^TM in order to manufacture the spacer for gas insulated switch. Through the simulation, the flow of the resin with respect to the diameter of the inlet was analyzed. It was found that the process was possible at a higher resin temperature as the diameter of the inlet increased. In addition, through thermal analysis during injection of the resin, it was confirmed that a stagnation phenomenon occurred at the insert portion during injection molding, and the temperature of the resin was higher than that of the mold. As in this paper, if the spacer is manufactured by optimizing the injection hole and the temperature of the injection process based on simulation, it is expected that the spacer can be manufactured with high productivity.

• Journal of IKEEE
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• v.25 no.3
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• pp.517-527
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• 2021

This paper presents the phase-shift full-bridge DC-DC converter using the one-chip micom. The proposed converter primary is the full-bridge power topology that operates with the unipolar pulse-width modulation (PWM) by the phase-shift method, and the secondary is the full-bridge full-wave rectifier composed of four diodes. The control of proposed converter is performed by the one-chip micom and its MOSFET switches are driven by the bootstrap circuit. Thus the total system of proposed converter is simple. The proposed converter achieves high-efficiency using the resonant circuit and blocking capacitor. In this paper, first, the power-circuit operation of proposed converter is explained according to each operation mode. And the power-circuit design method of proposed converter is shown, and the software control algorithm on the micom and the feedback and switch drive circuits operating the proposed converter are described, briefly. Then, the operation characteristics of proposed converter are validated through the experimental results of a designed and implemented prototype converter by the shown design and implementation method in this paper. The highest efficiency in the results was about 92%.

• Journal of Acupuncture Research
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• v.38 no.3
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• pp.236-241
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• 2021

There were 26 Bell's palsy cases at the Jecheon Hospital of Korean medicine, Semyung University from February 1, 2019, to February 28, 2021 reviewed. One group (A group) was treated with Bamboo salt pharmacopuncture and cervi cornu parvum pharmacopuncture (CC) pharmacopuncture in the paralyzed side of the face, and the other (B group) group was treated with Soyum pharmacopuncture, and hominis placenta (HP) pharmacopuncture. Amid a paucity of studies that have used bamboo salt and CC pharmacopuncture to treat Bell's palsy, this study aimed to demonstrate possibility of treatment effect on Bell's palsy. In addition, this study was to see if the effect of determine a change in pharmacopuncture was changed according to the progress of Bell's palsy symptoms was effective. Bell's palsy was improved in each group. Altough there were no significant differences in improvement between two groups, Bamboo salt pharmacopuncture and CC pharmacopuncture could be expected to be effective on the paralyzed face. Furthermore, it is effective to switch pharmacopuncture according to the progress of Bell's palsy.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.11-17
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• 2021

Software-defined networking provides a programmable and flexible way to manage the network by separating the control plane from data plane. However, the limited switch memory restricts the number of flow entries in the flow table used to forward packets. This leads to flow table overflow and flow entry reinstallation, which severely degrade the network performance. Therefore, this paper proposes a comprehensive policy for timely eviction of inactive flow entries to optimally maintain flow tables usage. In particular, statistics of user datagram protocol flow entries are periodically sampled to enable the inactive entries to be evicted early. Through traffic-based experiments, we found that the proposed system reduces the number of overflow occurrences and flow entries reinstallation compared to the random and FIFO policies.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.2
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• pp.82-89
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• 2021

This study proposes a DAB two-stage series structure with insulated bidirectional DC-DC converter for two-way power transfer between the renewable energy of high voltages (1 kV and above). The proposed circuit transforms the existing DAB converter into a two-stage series structure to reduce the pressure in the switch. The problem of power imbalance occurring in the design of the DAB converter second-stage series is improved by applying the cell balancing method circuit and the common mode coupled inductor using an external flying capacitor instead of reflecting the existing improvement measures, voltage balance control, and inductor current control. In addition, a no-load supercharging sequence is proposed in high voltages and high-speed switching by using the fixed duty output method. This study presents the analysis results through the structure of the proposed circuit, the principle of improving the power imbalance problem, and simulations. Prototypes were manufactured to meet the specifications of input/output voltage of 1700 V, maximum load of 65 kW, and switching frequency of 51kHz, and the validity of the topology was verified using the experimental results and efficiency data.

• Journal of Lipid and Atherosclerosis
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• v.7 no.2
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• pp.77-87
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• 2018

Lowering serum low-density lipoprotein cholesterol (LDL-C) is the mainstay for reduction of risk of cardiovascular disease (CVD), the second most common cause of death in Korea. The 2015 Korean guidelines for management of dyslipidemia strongly recommend the use of statins in patients at risk of CVD. Statin therapy, which is the gold standard for CVD, reduces LDL-C level by 40% to 60% and is generally well tolerated. However, many patients are intolerant to statins and discontinue therapy or become nonadherent to therapy because of actual/perceived side effects. The most common of these side effects is the statin-associated muscle symptom (SAMS). Discontinuation and repetitive re-challenge with statins can help identify SAMS. If serum creatinine kinase level is more than 10 times the upper limit of normal, statin therapy must be stopped immediately, and the physician should identify possible causes including rhabdomyolysis and treat appropriately. In other patients, it might help to switch to a less potent statin or to use statins at intermittent non-daily dosing. To achieve target LDL-C level, non-statin lipid-lowering therapies such as dietary modifications, ezetimibe, and bile acid sequestrants may be added. Several new drugs have recently been approved for lowering LDL-C level. Alirocumab and evolocumab are monoclonal antibodies that inhibit proprotein convertase subtilisin/kexin type 9, and both drugs cause large reductions in LDL-C, similar to statins. Lomitapide and mipomersen are orphan drugs used as adjuncts to other lipid-lowering therapies in patients with homozygous familial hypercholesterolemia.

• Korean Journal of Clinical Pharmacy
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• v.28 no.4
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• pp.263-272
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• 2018

Nonprescription drugs have become increasingly important in Korean healthcare. By leveraging lower-cost drugs and reducing expenditure associated with fewer physician visits, the nonprescription segment can deliver tremendous value to individual consumers and the Korean healthcare system. Many countries have provided simpler and more rapid routes to market entry for qualifying nonprescription drug products, using the established data on drug safety and efficacy, as well as public and professional opinion. In US, the FDA waived the pre-approval process for over-the-counter (OTC) drugs marketed through the OTC Monograph Process. In Australia and Canada, different OTC product application levels are defined, with a reduced level of assessment required when the risks to consumers are considered low. Japan established a new OTC evaluation system in 2014 to facilitate the Rx-to-OTC switch process. The legislative framework for medicinal products in the European Union allows for drugs to be approved with reference to appropriate bibliographic data for old active substances with well-established uses. Through a comparison of the regulatory framework and the requirements for nonprescription approval process in different countries, several ways to improve regulatory practice for the evaluation of nonprescription drugs in Korea have been suggested.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.149-157
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• 2018

In this paper, we propose an attack detection technology using SDN Controller to study security threats in IoT environment. The research methodology has been developed by applying IoT security threat management technology to the IoT layer and analyzing the research trend of applied security technology. The study results show that the effectiveness of the detection method using the sampling method is studied by adding OpenFlow based SDN Controller to the network switch equipment of the existing IoT network. This method can detect the monitoring and attack of the whole network by interworking with IDS and IPS without affecting the performance of existing IoT devices. By applying such improved security threat countermeasure technology, we expect to be able to relieve anxiety of IoT security threat and increase service reliability.