• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.410-419
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• 2017

Since the beginning of the water shortage by disasters such as global warming, environmental pollution, and drought, development of original technology and studies have been undergone to increase availability of water resources. Among them the water treatment separation membrane technology is an environmentally friendly process that does not use chemicals and shows better water quality improvement effect than conventional physicochemical and biological processes. The water treatment membrane can be applied to various fields such as waste water treatment, water purification treatment, seawater desalination, ion exchange process, ultrapure water production, organic solvent separation and water treatment technology, and it tends to expand the range of application. In the core technology of water treatment membrane, researches are being actively carried out to develop a separation membrane of better performance by controlling the pore size to adjust the separation performance. In this review, we summarized the frequency of announcement by country and organization through the technological competitiveness evaluation of patents and papers of the water separation membrane. Also, we evaluated the results from membrane research for waste water treatment, water purification treatment, seawater desalination, ion exchange process and present the future direction of research.

• Environmental and Resource Economics Review
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• v.26 no.3
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• pp.451-472
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• 2017

An OPEC production announcement is a major source of supply disruption that has a significant impact on the international crude oil market. In this study, the effects of OPEC's announcements are analyzed using event study methodology. Considering the oil price volatility and structural changes in the oil price, we divide the entire period into three periods and analyze the impact of OPEC's production quota announcements, including 'cut', 'hike', and 'maintain'. As a result of the analysis, we observe that the degree and direction of abnormal returns differ according to the announcements in each period. In addition, by subdividing oil price surge and plunge period into two sections, we analyze the effect of OPEC's 'maintain' announcements. During the oil price plunge period, the amount of abnormal returns was significant. This study provides policy implications for oil trading strategies and for the impact of OPEC announcements during periods of oil price fluctuation.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.225-235
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• 2017

Firms employ one of two stock repurchasing methods, either direct open market repurchase or indirect repurchase through trust contracts. Since these two methods have some regulatory differences, managers of firms may use a repurchasing method as a signal to convey the information to the market. Therefore, this study investigates the relationship between stock repurchasing methods and implied cost of equity of firms. The results show that there is a significant and negative relationship between stock repurchase announcement and cost of equity. In addition, the implied cost of equity for firms employing direct open market repurchase is significantly lower than those of firms that use indirect repurchase method. Overall, the market accurately reflects the information conveyed by two stock repurchasing methods into cost of equity of firms.

• Health Policy and Management
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• v.29 no.3
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• pp.374-378
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• 2019

After the announcement of Moon Jae-in Government's plan (Moon's Care) for Benefit Expansion in National Health Insurance in August 2017, it is necessary to monitor the effects of the policy, especially household out-of-pocket payments (OOP). This paper aims to observe the current status and trend of OOP in Korea. Current health expenditure (CHE) was 144.4 trillion won in 2018, which accounts for 8.1% of gross domestic product (GDP) increased 9.7% from the previous year. Although GDP's share of CHE has been close to the average of the Organization for Economic Cooperation and Development (OECD) countries, the public fund's share was 59.8% of the total in 2018, which was lower than the OECD average of 73.5%. OOP's share was 32.9% in 2018, which decreased from 37.4% in 2008. The share of OOP of non-covered services was 20.0% in 2018, which decreased from 22.9% in 2008. The share of cost-sharing with third-party payers was 12.9% in 2018, which decreased from 14.5% in 2008. The OOP of non-covered services was significantly decreased in hospital and inpatient curative care, but the OOP of non-covered services was significantly increased in the medical clinic. The effect of Moon's Care was not showed in OOP through the results of 2017 and 2018, but further monitoring is needed because the Moon's Care is progressing and the observational period is short.

• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.19-35
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• 2019

Objectives : The purpose of this study is to review which acupoints and meridians are selected to treat visceral pain in articles published in international journals and to investigate quality of reporting acupuncture intervention according to the STRICTA guidelines. Methods : Electrical and hand search were conducted in PubMed, EMBASE, MEDLINE, and Cochrane Library for acupuncture studies on visceral pain in human and animals. Reporting quality of intervention was evaluated using the revised STRICTA guidelines. Results : We included 51 articles (7 clinical studies and 44 animal studies) in this study. The most frequently adopted meridians and acupoints were Stomach meridian, Spleen meridian, Conception Vessel meridian, and ST36, CV4, SP6, LI4, PC6, SP9, ST25, ST37 in clinical studies. In animal studies, Stomach meridian, Conception Vessel meridian, Pericardium meridian and ST36, ST37, CV12, PC6 were most frequently used. Animal studies showed significantly lower quality of reporting compared to clinical studies. According to the analysis on the effect of year of publication of articles, announcement of STRICTA guidelines did not improve the quality of reporting for studies on visceral pain. Conclusions : These results suggest that both proximal and distal acupoints based on meridian theory were used to study the underlying mechanisms of visceral pain both in human and animal studies. Guidelines of acupuncture intervention reporting for animal study is necessary to improve the quality of evidence, and it will also allow us the integrative understanding of the mechanisms and clinical effects of acupuncture treatment in human and animal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.765-773
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• 2018

The purpose of this study was to investigate the effect of Healing Beat on autonomic balance, heart rate, and anxiety in healthy adults exposed to stressors. Data were collected from 64 healthy volunteers who volunteered after responded to a recruitment announcement at D City University and analyzed using descriptive statistics, the X2-test, the t-test, and repeated measures of ANOVA. Results showed that both experimental and control general characteristics and variables were homogeneous. Significant intergroup differences were obtained for autonomic balance (F = 6.151, p <.001), heart rate (F = 5.455, p <.001), and anxiety (t = -7.633, p <.001). These results indicate Healing Beat is effective at relieving anxiety in stressful situations, and that Healing Beat can be used to relieve stress in many clinical situations or daily life when individuals are exposed to various stressors.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.32-38
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• 2023

This study investigates the influence of particulate matter concentrations on the incidence of asthma, focusing on the delayed onset of symptoms and subsequent medical consultations. Analysis incorporates a four-day lag from the initiation of fine dust exposure and compares asthma patterns before and after the World Health Organization's (WHO) classification of fine dust as a Group 1 carcinogen in November 2013. Utilizing daily PM10 data and asthma-related medical visit counts in Seoul from 2008 to 2016, the study additionally incorporates Google search frequencies and newspaper article counts on fine dust to assess public awareness. Results reveal a surge in search frequencies and article publications after WHO announcement, indicating heightened public interest. To standardize the long-term asthma occurrence trend, the daily asthma patient numbers are ratio-adjusted based on annual averages. The analysis uncovers an increase in asthma medical visits 2 to 3 days after fine dust events. Additionally, greater public awareness of fine dust hazards correlates with a significant reduction in asthma occurrence after such events, even within 'normal' fine dust concentrations. Notably, behavioral changes, like limiting outdoor activities, contribute to this decrease. This study highlights the importance of analyzing accumulated medical data over an extended period to identify general public behavioral patterns, deviating from conventional survey methods in social sciences. Future research aims to extend data collection beyond 2016, exploring recent trends and considering the potential impact of decreased fine dust awareness amid the COVID-19 pandemic.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.3
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• pp.286-306
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• 2011

Based on the announcement by the National Competitiveness Council in 2008, this study analyzed the direction of the changing policy in Seoul Metropolitan Area promoted by the current government and to inquire into such the effect, research was done to study the changes in space demand by companies which respond sensitively to changes in regulation in Seoul Metropolitan Area. In addition, the effect of Seoul Metropolitan Area policy on company location is explored while company location changes and changes in direction of space demand due to easing of regulation in Seoul Metropolitan Area by the current government are examined. Research methods utilized empirical analysis and survey analysis. Empirical analysis utilized statistical data since 1980's. For survey analysis, the effect of changing policy in Seoul Metropolitan Area, which is an exogenous shock, on decision making of the enterprise is considered to derive the direction of demand for company manufacturing lots. The results of the study showed that decision for company location or factory size has been affected greatly by Seoul Metropolitan Area policy and domain regulation and institution to restrict permission area of a manufacturing building from the law of improvement plan of the Metropolitan area were the biggest regulatory policies. Due to easing of regulation in Seoul Metropolitan Area by the current government, the demand for manufacturing lot is expected to increase. In particular, the demand for manufacturing lot is expected to increase centered around Seoul Metropolitan Area and Chungcheong province while demand is expected to decrease in Gangwon province. The reason is because company preference is high for the Seoul Metropolitan Area which has the best transportation/logistics and market conditions in Korea. But in the case of Southeast region and Daegyung region that form exclusive economic zones, changing policy in Seoul Metropolitan Area has little impact. In the case of Seoul Metropolitan Area, demand increase does not occur in the entire area but instead, demand is expected to increase in growth management zones.

• Management & Information Systems Review
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• v.35 no.3
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• pp.195-212
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• 2016

Utilizing intra-day volume weighted average price (VWAP) based on 1 minute return data of stocks traded on the Korean Stock Exchange, this paper examines and analyzes abnormal returns in reaction to patent listing disclosures as well as the cumulative abnormal returns, traded volumes, the interaction of VWAP spreads, the reaction of volumes, the reaction of VWAP spreads and the realized returns obtained from trading using an event driven arbitrage strategy. The results of the aforementioned research topics are follows. First, our analysis suggests that on average, 0.92% positive cumulative returns arise 1 minute after the patent listing disclosure announcement with high statistical significance, thereby reconfirming that the Korean stock market is a semi-strong form of the efficient market. Employing 3 separate panel tests differentiated by the size factor, we find that the abnormal returns of small sized stocks were less than the returns of medium sized stocks, which goes to support recent research findings suggesting that the size premium is no longer existent in the Korean stock market. Secondly, we show that among the event driven type strategies, the most outstanding realized returns are from the market making strategies. Furthermore, placing market order trades only at the bid or ask price resulted in negative returns. This implies that strategies utilizing a combination of market orders and limit orders, order cancelations ratios and order flows can enhance realized returns.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.257-263
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• 2010

We studied about the difference of division public announcements by corporation size and ownership structure from 1999 to 2005. The results is as follow : First, we found most positive numbers in division corporation's CAR. This supports the existing research that corporation division is evaluated positively in the market. We found CAR as largest shareholders' holding more than 40%, which is greater than 0-20% & 20-40%, that shows relatively more negative CAR. So, the exceeded largest shareholders' holding rate (i.e., over 40%) can be a factor for decreasing corporations' value. Also, most positive CAR shows relatively small variation regarding corporation size knowing that big sized corporations have relatively small variation than small sized corporations. Second, we studied about relationship between corporate ownership structure and division public effects and found relatively a little effect by large shareholders, foreign investors' holding variables on division public.