• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.207-211
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• 2005

This research is aimed to study the finishing material applied in interior space for improving residential environment. First of all, it finds out what is 'Sick Building Syndrome' and 'Sick House Syndrome', how harmful to human body about indoor air pollution substance (such as volatility organic compound, formaldehyde) and investigate the effect when the environment-friendly finishing material is used. Secondly, classify and examine all kind of finishing material applied in interior space. Finally, after emphasize the importance of environment-friendly finishing material from domestic or overseas, this research suggest the basic information of environment-friendly finishing material in order to use in the future buildings.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.38-42
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• 2004

In this research, we used discharge tube without dielectric bead or with dielectric beads($SiO_2$, $Al_2O_3$, or $ZrO_2$), and discharge in water for removal of Escherichia coli. At the result of experiments, the removal characteristics of Escherichia coli appeared relation ratio to input voltage. Because, the electric field of discharge tube is increased when input voltage is increased. And, discharge tube used dielectric bead($ZrO_2$), the removal characteristics of Escherichia coli was better than cases of else.

• Journal of Powder Materials
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• v.3 no.3
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• pp.153-158
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• 1996

The exhaust gas from vehicle engines and industrial boilers contains considerable amount of harmful nitrogen monoxide(NO) which causes air pollusion and acid rain. To remove NO catalytic reduction processes using Cu ion exchanged ZSM-5 zeolite have been widely studied. In this study, an attempt was made to fabricate Cu/zeolite catalyst by using high energy ball mill. The catalytic performance of ball milled Cu/ZSM-5 zeolites is analyzed and optimum copper contents was determined. The processing variables were reaction temperature and copper contents. Complete removal of NO gas was obtained at the temperature of 553 K on 10wt.% CU/ZSM-5 mechanically alloyed composite powders. Mechanically alloyed CU/ZSM-5 catalyst showed homogeneous distribution of Cu in ZSM-5.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.175-176
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• 2015

봄철 황사나 대기오염으로 인하여 실내에 오염된 공기가 유입되고 있다. 이를 정화하기위해 현재 실내에서는 공기청정기를 사용한다. 그러나 기존의 공기청정기는 이미 실내공기가 오염되었을 때 작동한다. 이를 보완하고자 본 논문에서는 방충망형 오염공기 차단기를 제안하였다. 방충망형 오염공기 차단기는 방충망에 고압의 DC 전압을 인가하여 코로나현상을 일어나게 하도록 만든 장치이다. 코로나 현상이 일어나면 주변 공기가 이온화 되는 원리를 이용하였다. 고압의 DC 전압을 발생시키기 위해 Full-Bridge 인버터를 이용하여 LC공진으로 변압기의 1차측 전압을 상승시켰고, 권선비를 이용하여 변압기 2차측 전압을 승압하였다. 마지막으로 배전압 정류회로를 설계하여 최종 DC전압을 생성하였다. 실험을 통해 제안한 방식의 유용성을 검증하였다.

• Communications for Statistical Applications and Methods
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• v.25 no.6
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• pp.619-631
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• 2018

Functional data analysis continues to attract interest because advances in technology across many fields have increasingly permitted measurements to be made from continuous processes on a discretized scale. Particulate matter is among the most harmful air pollutants affecting public health and the environment, and levels of PM10 (particles less than 10 micrometers in diameter) for regions of California remain among the highest in the United States. The relatively high frequency of particulate matter sampling enables us to regard the data as functional data. In this work, we investigate the dominant modes of variation of PM10 using functional data analysis methodologies. Our analysis provides insight into the underlying data structure of PM10, and it captures the size and temporal variation of this underlying data structure. In addition, our study shows that certain aspects of size and temporal variation of the underlying PM10 structure are associated with changes in large-scale climate indices that quantify variations of sea surface temperature and atmospheric circulation patterns.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.75-86
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• 2020

Objectives: In this study, we assessed respiratory hazards in the working environment as the work-relatedness of occupational diseases were examined. Methods: The subjects of the study were three Korean meat roasting restaurants, one Chinese restaurant, and two cafeterias. Measurement items were total dust, respirable dust, fine dust (PM_2.5), PAHs, TVOCs, temperature, humidity, carbon monoxide, carbon dioxide, and nitrogen dioxide. Results: The concentration of total dust and respiratory dust in the restaurant was low. Most PAHs were undetectable, but some Napthalene and Acenaphthylene was detected. Thirteen kinds of PAHs were detected in one sample of roasted meat, and Benzo(a)pyrene was 1.496 ㎍/㎥. PM_2.5, TVOCs, CO, and CO₂ were instantaneously high, but the average concentration was low. NO₂ was not detected. Conclusions: The results show that harmful substances such as PM_2.5, PAHs, CO, and TVOCs were generated in the air in the catering industry. When roasting meat, Benzo(a)pyrene, a carcinogen related to lung cancer, was generated among PAHs. Lung cancer can occur when working for a long time in such a working environment. Therefore, it is necessary to improve the working environment for the health of restaurant workers, and it is necessary to evaluate the concentration of harmful substances by cooking method through further research.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.326-335
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• 2017

It is known that diesel engines have the disadvantage of high emission levels of NOx and PM. Therefore, many combustion strategies have been developed to reduce these harmful NOx and PM emissions in a diesel engine. Among these strategies, HCCI(Homogeneous Charge Compression Ignition) and PCCI(Premixed Charge Compression Ignition) are the most popular as these can reduce NOx and PM simultaneously. However, when a single fuel like diesel is applied, it is difficult to control the combustion phase and this can lead to power reduction. In this study, premixed gasoline and pilot diesel were used to overcome the problems of controllability of the combustion phase and harmful emissions. We injected gasoline directly into the combustion chamber and the gasoline/air mixture was ignited with a pilot diesel fuel near the top dead center. The results showed that the combustion and emission characteristics of dual-fuel combustion were comparable to those of conventional diesel combustion. When we applied the dual-fuel PCCI combustion concept, more than 90 % of NOx and PM emission was reduced simultaneously without significant degradation of efficiency compared to conventional diesel combustion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.583-589
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• 2016

Volatile organic compounds(VOCs) are regarded as a harmful cause substance not only causing air pollutions but also causing global warming phenomenon. For this reason, VOCs are managed politically to reduce emissions by each country. In particular, the vapor from the gas station contains VOCs which is harmful to the human body such as carcinogens benzene and pollute the atmosphere, the Ministry of Environment defined every gas station must install vapor recovery equipment to recover volatile organic compounds. Recently, there are many accidents caused by existing vapor treatment methods, the liquefaction recovery technology is getting the spotlight to cool the vapor at the field. However, because the liquefaction recovery technology have risks of fire or explosion in accordance with temperature, the real time monitoring is critical factor. In this paper, we implement an Android-based monitoring application for liquified vapor recovery device which attached sensor module for temperature and power to monitoring real time information.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.580-585
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• 2009

Harmful Algal Blooms (HABs), caused by Cochlodinium polykrikoides that causative fishery mortality, impact on aquaculture and economic loss appear particularly in summer and fall seasons in the Korean seas. It was studied on characteristics of HABs in the South Sea of Korea by using satellite and in-situ data. The in-situ data encompassed oceanic and meteorological data from July to October 2002-2008 and satellite data from July to October 2002-2006. Chlorophyll concentrations were calculated using Seaviewing Wide Field-of-view Sensor images by an Ocean Color (OC4) algorithm, and HABs were estimated using the Red tide index Chlorophyll Algorithm (RCA). The HAB occurrences were dominant when water temperature was $22.6-28^{\circ}C$ in August. The frequency of the individual numbers during 2002-2008, the HABs more than 1000 cells/ml (alert condition), were 73.57 %. In meteorological data from July to September during 2002-2008, the average precipitation, the mean air temperature, the mean wind speed and direction, and the sunshine were 9.31 mm/day, $24.07^{\circ}C$, 2.34 m/s and easterly, and 1-11 h, respectively. Our results suggest that the upwelling is caused by southwesterly wind in summer season and the Tsushima Warm Current which have influenced on the dispersion and moving of HAB (chlorophyll). In addition, the fresh water from Nakdong River, as the source of nutrients, also influences the occurrence of HABs.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.1-12
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• 2001

Objective: The present study was done to clarify the effects of nicotine and nicotine tartrate on the mouse oocyte maturation in vitro. Methods: GV (germinal vesicle) oocytes were isolated from Graafian follicle of ovaries with sharp needles under a stereomicroscope from female mouse of ICR strain (4 weeks old). Collected oocytes were cultured for 17 hours at $37^{\circ}C$, 5% $CO_2$ in air and 100% humidified condition in incubator. New MHBS was the basic medium used in which nicotine, nicotine tartrate, and mecamylamine (antagonist of nicotinic acetylcholine receptor) were added depending on the experimental group. GV oocytes were cultured in one of these media. Results: Nicotine ($300{\mu}M{\sim}5mM$) had no effects on GVBD (germinal vesicle breakdown) compared to the control, but increasing concentration of nicotine led to an decrease in the first polar body formation. However, nicotine ($10{\sim}500{\mu}M$) induced GVBD in a dose-dependent manner of GV oocytes in a medium containing dbcAMP. Nicotine tartrate ($50{\mu}M{\sim}5mM$) had no effects on GVBD compared to the control but, increasing concentration of nicotine tartrate led to an decrease in the first polar body formation. Mecamylamine $10{\mu}M$ added to the medium containing nicotine ($300{\mu}M{\sim}5mM$) showed higher percentage of the first polar body formation compared to the nicotine ($300{\mu}M{\sim}5mM$) treatment group. Mecamylamine $10{\mu}M$ added to the medium containing nicotine tartrate ($50{\mu}M{\sim}5mM$) showed higher percentage of the first polar body formation compared to the nicotine tartrate ($50{\mu}M{\sim}5mM$) treatment group. Conclusion: The present study suggest that nicotine and nicotine tartrate have the harmful effects on the meiotic maturation of the mouse oocytes in vitro. However, mecamylamine block harmful effects of nicotine and nictine tartrate.