• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.77-83
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• 2021

The purpose of the study is to evaluate the effect on medical application and convergence for the efficient disaster responses in the massive radiological events by comparison of two types of survey-meters(hand held survey-meter and transportable portal monitor). In the simulated radiation disaster drill, twelve participants randomly wore a personal protective equipments (PPE) with twelve check source. We measured participants to detect five real radioactive sources of the twelve check sources, using two types of survey meters. The primary outcome was the measuring time. The secondary outcome was the sensitivity and specificity of the detection of the real radioactive source. The average time by the hand held survey meter was 231.9 ± 116.6 seconds, and the time by transportable portal monitor was statistically shorter 8.690 ± 1.667 seconds. There was no difference in the sensitivity and specificity between two survey meters. The transportable portal monitor survey meter was considered to have medical application and play an important role in radiological disasters.

• Analytical Science and Technology
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• v.27 no.1
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• pp.1-10
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• 2014

The $PM_{10}$ and $PM_{2.5}$ samples were collected at Gosan Site of Jeju Island, and analyzed, in order to investigate the size distribution and pollution characteristics of their components. $NH{_4}{^+}$, nss-$SO{_4}^{2-}$, $K^+$, and $CH_3COO^-$ were mostly existed in fine particles. Meanwhile, $NO{_3}{^-}$ was distributed in both fine and coarse particles, and $Na^+$, $Cl^-$, $Mg^{2+}$, nss-$Ca^{2+}$ were rich in coarse particle mode. The concentrations of nss-$Ca^{2+}$ and $NO{_3}{^-}$ were increased 36.7 and 3.2 times in coarse particles, and 15.0 and 3.1 times in fine particles during the Asian Dust periods. Especially, the concentrations of crustal elemental species such as Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba were highly increased for those periods. In the haze events, the concentrations of secondary air pollutants were increased 1.3~2.6 and 1.5~4.2 times in coarse and fine particles, respectively. Moreover, the remarkable increase of $NO{_3}{^-}$ concentration was also observed in fine particle mode. The factor analysis showed that the composition of coarse particles was influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, the fine particles were influenced by anthropogenic sources, followed by marine and soil sources.

• Journal of Environmental Health Sciences
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• v.23 no.2
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• pp.57-63
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• 1997

This study was carried out to find the adverse health effects of ozone by papers, the potential indoor sources of ozone by papers, and then the removal mechanism of ozone by experiments. The exposure of individuals to excessive levels of ozone both in the industrial and ambient environment is a continuing public health concern. Ozone indoors may play a role in generating secondary pollutants that may have adverse health effects. The removal efficiency of ozone was studied by (1) the effect of concentration on breakthrough time, (2) the effect of flow rate on breakthrough time, (3) the effect of adsorbent's weight on breakthrough time, (4) the effect of temperature on breakthrough time, (5) the application of Langmuir's isotherm equation in using activated carbon. The followings are the conclusions that were derived from this study. 1. In the effect of concentration on breakthrough time, the adsorption capacity of activated carbon was inversely proportional to ozone concentratuion (0.1, 0.2, 0.3 ppm). 2. In the effect of flow rate on breakthrough time, the service life of activated carbon was inversely proportional to flow rate (2, 8, 14l/min). 3. The difference in removal efficiency of ozone between weights(100 mg and 150 mg) was seen. And when weight of activated carbon was 100 mg and 150 mg, pressure loss was 4-5mmHg and 6-7mmHg, respectively. It is required to study relations among flow rate and adsorbent's weight and ventilation quantity, too. 4. Generally, Langmuir's equation, one of the oldest and most used frequently isotherm equation, applies to chemisorption. In case of ozone, when the weight of activated carbon was 70 mg and temperature 40, slope(1/a) was $6.25\times 10^{-1}$ and intercept(1/ab) was $1.9\times 10^{-4}$ (average r=0.94).

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.215-238
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• 1983

The study was conducted to indentify systematically current marketing structure and markeiing efficiency of major cash crops such as red peppers and garlics. That various data and information have been used to analyze the problems related, some of them have come from secondary sources, but major parts of real circum stances were primarily obtained from the scheduled field survey. Some of valuable facts and consequences stemmed from the research can be summarized as fellows: First of all, the commercial rates of peppers and garlics produced by sample farms were 87.5 percent and 69 percent, respectively. On the other hand, annual handling volumes per marketing firm of those two crops were on the average estimated into 51,000 kyun(about 600gr) for peppers and 20,000 hundred bulbs of garlic. As seen physical losses over the entire marketing channels of each crop, it was approximately calculated in 14.7 percent of peppers and 21.1 percent of garlic, respectively. Secondarily, it was found that marketing chanells of these crops are very diversified and complex. However, the five-staged chanell is typical: i.e., from producers to local consigners, to local carry-out merchants, to consigner-wholesales, and finally to retailers. Thirdly, it was also estimated that gross marketing margin, marketing cost and profit based on average grade of peppers were 56.1 percent, 22.6 and 33.5 percent, respectively, having 43.8 percent of farmer's share, and those of garlic 38.9, 17.1, 21.8 and 61.1 percent, separately. To the end, it seems that current collective bargaining power of farmers' cooperatives is virtually weak compared to free individual marketing firms in terms of bssiness volumes and quantity handled over the year.

• New & Renewable Energy
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• v.16 no.3
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• pp.13-26
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• 2020

This study analyzed whether the diffusion of new and renewable energy contributed to mitigating emissions of various air pollutants, including particulate matter, using panel econometric models. The theoretical foundation of such econometric models is based on the Environmental Kuznets Curve (EKC) hypothesis, which assumes an inverted U-shaped relation between national income and environmental pollution, as originally proposed by Grossman and Krueger. We examined whether there are inverted U-, U-shaped, or N-shaped relations between national income and air pollution. We demonstrate that increases in new and renewable energy significantly mitigated emissions of CO, NO_X, and PM2.5. Additionally, we included NO_X, SO_X, PM10, and VOCs as secondary emission sources of PM2.5 and found that emission of PM10 resulted in the highest PM2.5 emissions, followed by NO_X and SO_X emissions. The impact of new and renewable energy on air pollution varied across regions. Increase of new and renewable energy in the Honam region significantly mitigated CO, NO_X, and TSP emissions, while that in the Youngnam and metropolitan areas did not significantly mitigate air pollution overall. There was a U-shaped relationship between air pollution and national income for CO, NO_X, PM2.5, and SO_X, while an inverted N-shape was observed for PM10.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.253-259
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• 2015

In this paper, we propose a transformer of alternating voltage source utilizing a semiconductor, operating in bidirectional fashion. Transformer is a device transferring energy by inductive coupling between its winding circuits. Conventional transformer is a device, composed of a primary coil and a secondary coil, transforming an alternating voltage. The system we propose is designed with a single circuit transforming the level of voltage signal in two ways; from the source to the load, and vice versa. For semiconductor switches, the NPN transistor is connected to the alternating voltage source terminal, and emitter terminal is connected to the inductor in the system as an energy storage element. The control signal is applied to the base terminal of the semiconductors. We have shown that the system we propose, by adopting only one circuit, drives an alternating voltage transformer that changes the amplitudes of voltage signal in reciprocal way.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.477-486
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• 2017

This review provides an overview of dietary nucleotides as an alternative to in-feed antibiotics for weaning pigs. Dietary nucleotides are composed of DNA or RNA molecules and are normally contained in protein-rich feed ingredient, brewer's yeast, yeast extract, and milk. Weaning pigs are suffering from several stresses, such as environmental challenges (i.e. crowding, transportation, and feeding). Such stressors can damage the intestinal epithelium and cause an invasion by Escherichia coli, secondary inflammatory responses, and post weaning diarrhea. To overcome weaning disorder, people often use antibiotics which reduce symptoms and boost growth performance. However, since antibiotics were banned due to concerns of antibiotic resistant bacteria, researchers are studying alternative materials to antibiotics. Dietary nucleotides are one of the alternative materials for replacing antibiotics and can be used in abnormal conditions, such as weaning diarrhea, low digestibility, and disease condition. Nucleotides have substances that have important roles in cell division and cell growth, affecting growth performance, intestinal condition, and immunological effect at the weaning stage. However, nucleotides' composition is very different between sources and this aspect makes it difficult to utilize nucleotides at the weaning stage. Therefore, this review paper focuses on i) the characteristics and functions of dietary nucleotides and ii) the effect of dietary nucleotides on the growth performance and immune system of pigs.

• Journal of Korean Library and Information Science Society
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• v.50 no.4
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• pp.405-428
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• 2019

This study discerned interactions that secondary students experience during their studies and information behaviors that explains their interactions. In addition, when young people collaborate with their friends, this study identified their actions, such as collecting, using, sharing, and generating information, and the social and cultural factors that influence the behavior. The research questions consisted of 'Radical Change Theory' focusing on the information behavior of the digital age youth and the type of radical change in the digital age. As a result of the research, the status of collaborative information behavior of middle and high school students was reflected in our educational reality. Students, however, approached and utilized various information sources, diversified their opinion sharing tools, and discovered channels that were different from adults and used them in information activities. Though not as anticipated, they suggested that the experience of collaboration helped the individual's growth.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.99-106
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• 2004

Pollution reduction and/or control technology becomes one of the pressing post-semiconductor research field to lead an advanced industrial structure. Soil/groundwater remediation techniques may act as a core technology which will create many demands on pollution reduction areas. A plenty numbers of abandoned metal mines were left without any remediation action in Korea, and it may be potential sources of heavy metal and As contamination in the ecosystem. In order to bring this soil contamination to a settlement, the emerging soil/groundwater remediation techniques should be introduced. Main research topics in the United States and Europe move towards the clean remediation technology without any secondary impact and the feasible application of developing technique into the field scale study. With these advantages, several soil/groundwater techniques such as electrokinetic soil processing, permeable reactive barrier, stabilization/solidification, biosorption, soil flushing with biosurfactant, bioleaching and phytoremediation will be summarized in this paper.

• Health Policy and Management
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• v.7 no.1
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• pp.73-99
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• 1997

This study was carried out by using questionnaires with 126 insurance societies from Sept. 30, 1995 to Oct. 18, 1995. The primary data collected bythe survey have been significantly supplemented by secondary data obtained from sources such as health insurance statistical year books and internal data in the Ministry of Health and Wolfare. Major findings were summarized as follows: Two financial coordinating programs have significantly improved financial status of regional health insurance societies: the catastrophic program for high cost medical care that was initiated in 1991 and the program for hospitalization cost of the aged in 1995. Another finding is that there existed ambiguity and inconsistency of equity index that had been used by stabilization programs and its side effects could not be ignored. Regression analyses were made to identify factors that affect financial transfers. Inde pendent variables in the regression include utilization frequency, dependancy ration, insurance contribution per insured and medical expense per insured. All these variables were statistically significant in the equations of applying distribution rate (distribution/contribution) and transfer rate (transfer/contribution) as dependent variables. Policy suggestions for the catastrophic program for high cost medical care are modifying the definition of catastrophic case and setting the maximum amount of subsidies for each society based on distribution rates. To solve the problems of the financial coordinating program for the aged, we could consider reimbursing more than 50% of the copayment incurred by the aged 65 or more and determining the maximum amount of outpatient copayment at 10,000 Won per day or per visit for the elderly. More fundamental improvement could be made by amending the Welfare Benefit Act to establish and expand medical and welfare facilities for the elderly.