• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.93-102
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• 2023

Objectives: With the evolution of direct reading sensors, it is possible to monitor several substances through telecommunication. However, there are some limitations on the use of direct reading technologies in the Occupational Safety and Health Act in South Korea, which only applies to detector tubes, noise, heat, and carbon monoxides. The number of chemicals and their amount of use have been continuously increasing in South Korea. The Ministry of Employment and Labor (MoEL) has concerns about worker's health because exposure is only covered for about 1.2% of all distributed chemicals. Using a direct reading monitor with photoionization detectors (PID-DRMs), gases and vapors chemicals can be measured. Based on the data, business owners are able to create corrective strategies, provide better working routines, and select correct respiratory equipment. PID-DRMs are less expensive and easier to handle for an owner voluntarily controlling chemicals emitted in the workplace. However, there are several limitations on using these PID-DRMs to the degree that the MoEL has not been able to select a legal monitor. The aim of this study was to review previous studies related to PID-DRMs and identify the characterization and limitation on PID-DRMs. Methods: To search for related studies on PID-DRMs, key words were used including direct reading monitors/instruments and/or photoionization detectors. Through that, four domestic and 15 international studies were reviewed. Results: Studies on PID-DRMs were conducted by chamber (enclosed, dynamic, walk-in) and in the field (experimental environment, actual environment). The concentration of PID-DRMs and charcoal tubes were compared for a single substance or mixture, or within the PID-DRMs. There was a high correlation between the two concentrations, but it did not meet the accuracy criteria (95% confidence interval, within 25%) of the NIOSH technical report (2012). In addition, differences in measured values occurred according to environmental factors (temperature, humidity) and high concentration, and concentration values tended to be underestimated due to contamination of the sensor. As a way to improve the accuracy of PID concentration, it was proposed to use correction factors, charcoal tube-based correction factors, or to calibrate the PID-DRMs in the same environment as the workplace. Conclusions: PID-DRMs can likely be used by business owners for the purpose of voluntarily managing the workplace environment, and it is expected that it will be possible to use them as legal equipment if a PID sensor can be upgraded and the limitations of the sensor (temperature, humidity, high concentration evaluation, sensor pollution) can be overcome in the near future.

• Journal of Korean Academy of Nursing
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• v.47 no.2
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• pp.211-221
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• 2017

Purpose: This study was done to develop and test a structural model on smoking cessation intention in technical high school men. The conceptual model was based on the theory of reasoned action and health promotion model. Methods: From May 29 to April 13, 2015, 413 technical high school students who smoked completed a structured questionnaire. Data were analyzed to calculate the direct and indirect effects of factors affecting smoking cessation intention. The SPSS WIN 20.0 and AMOS 21.0 programs were used. Results: The hypothetical model was a good fit for the data. The model fit indices were $x^2/df=2.36$, GFI=.95, AGFI=.92, NFI=0.97, and RMSEA=.05. Self-esteem had direct and indirect effects on smoking cessation intention. Attitude, subjective norm, and self-efficacy had direct effects on smoking cessation intention. Smoking knowledge and environmental factor had indirect effects on smoking cessation intention. This model explained 87.0% of the variance in smoking cessation intention. Conclusion: These results indicate that technical high school students' intention to stop smoking can be improved through an increase in self-esteem, negative environmental factors, attitude toward smoking cessation, subjective norm about smoking cessation, and self-efficacy for smoking cessation.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.857-860
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• 2009

This report examines the economic feasibility of a commercial 50,000 barrel per day direct/indirect coal liquefaction (DCL/ICL) facility to produce commercial-grade diesel and naphtha liquids from medium-sulfur bituminous coal. The scope of the study includes capital and operating cost estimates, sensitivity analysis and a comparative financial analysis. Based on plant capacity of 50,000BPD, employing Illinois #6 bituminous coal as feed coal the total capital cost appeared $3,994,858,000(DCL) and $4,942,976,000(ICL). Also, the internal rate of return of DCL/ICL appeared 13.27% and 12.68% on the base condition. In this case, coal price and sale price of products were the most influence factors. And ICL's payback period(6.8 years) was longer than DCL's (6.6 years). According to sensitivity analyses, the important factors on DCL/ICL processes were product sale price, feed coal price and the capital cost in order.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.27-42
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• 2009

The research aims to identify factors affecting the use of government export marketing assistance programs and future improvements of the programs. 500 Korean exporting firms were used as a sample and research hypotheses were tested by the structural equation modeling using AMOS 7.0. The empirical findings are as follows. First, exporting firms' awareness of export marketing assistance programs showed a positive impact on their use of the programs. Second, small exporters showed higher awareness and use of the programs than large ones. Third, the firms with low export intensity showed higher awareness and use of the programs than those with high export intensity. Fourth, exporters having high orientations for overseas market showed higher awareness and use of the programs than those with low international orientations. Fifth, exporters having high proportion of direct exports showed higher awareness and use of the programs than those with low proportion of direct exports. Also, the effects of these firm-specific characteristics on the use of the programs were found to be done indirectly, in other words, through the awareness of the programs. Therefore, it was concluded that export marketing assistance program would be differentiated and specialized to fit in with exporters' different exporting stages and needs. Also, in order to increase the use of the programs, exporters' awareness and knowledge of the programs have to be increased in advance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1373-1392
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• 2017

WiFi Direct (WD) is a state of the art technology for a Device-to-Device (D2D) communication in 802.11 networks. The performance of the WD system can be significantly affected by some key factors such as the type of application, specifications of MAC and PHY layer parameters, and surrounding environment etc. It is, therefore, important to develop a system model that takes these factors into account. In this paper, we focus on investigating the design parameters of the PHY layer that could maximize the efficiency of the WD 802.11 system. For this purpose, a basic theoretical model is formulated for a WD network under a 2x2 Multiple In Multiple Out (MIMO) TGn channel B model. The design level parameters such as input symbol rate and antenna spacing, as well as the effects of the environment, are thoroughly examined in terms of path gain, spectral density, outage probability and Packet Error Rate (PER). Thereafter, a novel adaptive algorithm is proposed to choose optimal parameters in accordance with the Quality of Experience (QoE) for a targeted application. The simulation results show that the proposed method outperforms the standard method thereby achieving an optimal performance in an adaptive manner.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.343-348
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• 2020

So far, research into multinational bank' overseas expansion has focused on foreign direct investment in the financial services industry. However, this study focused its existing theories on multinational banks on decision-making related to the type of overseas advancement of local financial institutions. For research, four environmental factors were considered: the scale of foreign direct investment, the scope of financial services that can be provided according to the rules of the host country, the corporate tax rate of the host country, and the level of development of the host country's banking industry. Through Kotra, data on the total amount of claims from 2010 to 2014 and the regulatory status for the country's financial industries were obtained. Hypothesis are built around theories and survey factors and has been demonstrated through regression analysis. Results show that Korean financial institutions tend to expand as legally independent subsidiaries where the corporate tax rate of the host country is relatively low. Contrary to the previous studies based on the U.S. banking corporates, results show that Korean banks tend to expand in forms of branches to the host countries with high level of banking system development.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.174-184
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• 2020

Objectives: The purpose of this study was to improve the working environment by identifying the work satisfaction of the cleaning workers of the aircraft and measuring and assessing the harmful factors of the cleaning process. Methods: We asked 23 cleaning companies for questionnaires and got 100 answers from 5 companies. The A-E Airline health manager has been contacted to establish a site survey schedule. The in-flight and lounge were measured using direct reading equipment. The harmful factor to be measured are noise, dust, temperature, volatile organic compound, total airborne bacteria, and total airborne bacteria. Results: Uncomfortable positions when replacing blanket, cleaning the table, and cleaning the floor have been identified as factor that reduce work satisfaction. Noise when replacing newspapers and cleaning toilets has been identified as a factor that lowers work satisfaction. Temperature and humidity were found to reduce work satisfaction during in-flight disinfection. Measurements of aircraft cabin and lounge with direct read equipment have shown that none of the items exceed the exposure criteria. Conclusions: As a result of measuring direct-reading equipment, no items exceeded the exposure criteria for each harmful factor. A clear survey of the working environment is required based on the results, and additional research is needed using personal sample measurement.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.581-589
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• 2020

Foreign factors play an important role in the socio-economic development of each country, in which foreign direct investment (FDI), foreign aid and exports of goods and services are always given top priority in undeveloped countries as well as developing countries. The purpose of this study is to examine the relationship between the various factors such as FDI, foreign aid, exports and economic growth in Vietnam. The empirical method employed secondary time-series data set during the period 1997-2018 to determine the impact of FDI, foreign aid and exports on economic growth in Vietnam by using a linear approach. For this study, data is collected from the World Bank and relevant agencies in Vietnam. An empirical model is built with a correlation and regression analysis between economic growth (GDP, current) and three independent variables (FDI, aid, exports of goods and services). The results show that the relationship between FDI (net inflows), aid, exports and GDP (current) has a positive effect at a 1% significance level. Based on these findings, the article recommends that Vietnam continues to seek effective solutions to maintain high economic growth rates by attracting FDI inflows, official development assistance (ODA), and increasing exports of goods and services.

• Journal of Korean Biological Nursing Science
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• v.20 no.2
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• pp.84-91
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• 2018

Purpose: The purpose of this study was to construct and test a structural equation model to investigate the risk factors of metabolic syndrome in rural women. Methods: The raw data in this study was collected from the Korean Genome and Epidemiology Study supervised by the Korea Centers for Disease Control and Prevention from 2005 to 2010. The data included physical examinations and surveys of 1,125 women, who resided in three rural areas of South Korea. The structural model in this study was composed of five latent variables: depression, stress, social support, health behavior, and metabolic syndrome. The structural equation model was used to assess the relationships among the variables. Results: The results of the study showed that depression and stress had direct effects on metabolic syndrome. Social support had a direct effect on health behavior and metabolic syndrome. Also, health behavior had a direct effect on metabolic syndrome. Conclusion: This study may serve as a guideline for interventions and strategies used to reduce metabolic syndrome in rural women.

• Journal of Korean Academy of Nursing
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• v.29 no.6
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• pp.1192-1207
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• 1999

The purpose of this study was to clarify the dynamic relationships among risk factors of arteriosclerosis and to develop and examine a model which could explain this relationship clearly. Data were collected from medical records of 400 male clients who visited a university hospital located in Inchon for physical examinations, from May 1996 to December 1996. Data were analyzed using the LISREL (Linear Structural Relationship) 8 program. To test the fitness of the hypothesized model, chi-square, RMSR (root mean square residual), GFI (goodness of fit index), CN (critical number) and Q-plot were used. Most of the fitness measurements, except the chi-square showed that the hypothesized model complimented the real data. According to the results, there were trends that obesity and hyperlipidemia were prevalent in heavier smokers, higher alcohol intakers, and groups who excercised less. Also, hypertension was more prevalent in older age, higher alcohol intaker, and higher serum lipid level groups. In contrast to the hypothesis, alcohol intake did not significantly affect serum lipid levels. This might be due to the serum lipid measurements (total cholesterol and trigryceride) used in this study to estimate hyperlipidemia. The direct effect of smoking on hypertension was not significant. However, the total effect of smoking on the hypertension was significant since indirect effects of smoking on hypertension, such as obesity and hyperlipidemia, were significant. The total effect of obesity on hypertension was significant since the indirect effect of obesity on hypertension via hyperlipidemia was significant, although the direct effect of smoking on hypertension was not significant. The degree of explaining hyperlipidemia with smoking, exercise, and obesity was high (60%), however, the degree of explaining obesity with age, smoking, alcohol intake, and exercise was very low (7%). On the basis of these results, high risk factors of arteriosclerosis such as hypertension, hyperlipidemia, or obesity are either directly or indirectly correlated each other. Therefore, it is difficult to predict outcomes for increasing or decreasing the risk factors by simply modulating a factor. Smoking, alcohol, and exercise both directly and indirectly affected major risk factors of arteriosclerosis. Therefore, correcting these variables is required to decrease risk factors. Finally, the relationship among other risk factors which have been known to be related with arteriosclerosis (diet, stress or hereditary) should be clarified in further studies.