• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.99-99
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• 2011

Fuel cell systems are a completely different form of electricity source that has been used so far and is an aggregation of multiple technologies with multidisciplinary features that can be operated safely only when gas and electrical safety are being considered. Since fuel cells generate through electrochemical reactions there are difficulties in ensuring electricity safety, power quality assessment, effective control and reliability standards for system faults using conventional inspection techniques and even though they are necessary as a primary means for reduction of CO2 owing to the Climate Convention, electrical safety assessment and measures are required for the prevention of faults in residential facilities. Although small-scaled distributed power supplies can be utilized as important means of peak control and energy management measures, research is required for observing the effects on the system and the development of inspection technology to ensure stable operation, and the electrical safety of residential fuel cell systems need to be assessed and the problems derived for establishing electrical safety standards. From the year 2002, Japan has established laws on technical safety standards and development and rules on the product specifications and standards for the industrialization of hydrogen fuel cells. Also, a lot of effort have been made for the commercialization of fuel cells by building one-stop certification services. Internationally, the IEC TC 105 has established international standards based on fuel cells. In order to protect the national interest, the country should be able to respond accordingly meet global standards. In fact, in Korea, to comply with the international trend, Korea Energy Management Corporation is establishing a certified agenda for fuel cells and Korean Agency for Technology and Standards is enacting technical standards for fuel cells. The current terms of fuel cells are that research has been focused more on the quality and performance of manufactured products rather than stable power operation and maintenance over time. In this paper, by considering the household fuel cell as a power device, the safety standards of the fuel cell system for a reliable operation with the existing power system is being proposed.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.222-228
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• 2001

Vibrio metschnikovii strain RH530 is a non-pathogenic, industrially-important alkaline protease producer which has been isolated from wastewater. In this paper, we report on the transformation of this strain by using the method of electroporation. A field strength of $7.5\;kVcm^{-1}$ and $25\;{\mu}F$, and using a 0.2-cm cuvette, appeared to be the optimal conditions for electroporation of the cells with the recombinant pSBCm plasmid carrying the vapK alkaline protease gene and the ColE1 replicon. Cells were subjected to osmotic shock in order to remove extracelluar DNase, and adding 200 mM of sucrose to electroporation buffer cells showed an increased transformation efficiency. Maximum efficiency of transformation was obtained at an early exponential growth phase. Using all of the conditions mentioned above, we routinely obtained a transformation efficiency of more than $10^4{({\mu}g\;plasmid\;DNA)}^{-1}$. The stability of the plasmid pSBCm in V. metschnikovii RH530 was 25% after 18h of growth (27 generations) in the medium without antibiotic selection. The insertion of the par locus to the pSBCm increased the stability of the plasmid up to 42% without selective pressure. The increase in plasmid stability was accompanied by the increase in the productivity of alkaline protease in the recombinant V. metschnikovii strain RH530. Determining optimal conditions for the transformation of the industrially-important, nonpathogenic Vibrio strain, and the improvement of plasmid stability by introducing the par locus into the high copy number plasmid vector, will allow the development of procedures involved in the genetic manipulation of this strain, particularly for its use in the production of industrial enzymes such as alkaline protease.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.94-107
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• 2006

This study aims to make an analysis of the innovation milieu in connection with the agricultural products and distribution system, and suggest policy alternatives for agricultural development and rural community. The decisions on the agricultural management are highly depend on the individual farm household' conditions(labor force or profits) rather than the crop units(JAKMOKBAN) or others. The partnerships of the innovation agents and trust between the individual farm households are considerably weak. From this paper, we suggest as follows to improve the regional agricultural industry and rural community development. The individual farm households need to convert market-oriented production system. And it is more important to enhance the innovation milieu than to enlarge physical infrastructure for agricultural development and rural community.

• 보존과학연구
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• s.6
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• pp.96-110
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• 1985

This report is briefly thied to introduce the kinds of clothes for the body of deceased and special features of remains in the era of the middle of Yidynasty found in Changheung IM's tomb, and some remarks related to the conservation treatment for shrouds as well. The contents of this report are summed up as follows:1. Included with the clothes of dead body of IM's clan were 2 pcs. Of woman's jacket, 2 pcs. of underpants, 1pcs. of single layered overcoat twithout cotton, 1pcs.of women's overcoat with a single layered thin cotton inside, women's socks, cushoned mattress, straw shoes and other hemp fabrics etc. By the observation of these remains, it is considered that they dressed the deceased with new cloth taken from the unsuals not prepared specially and stored beforehand for such as occasion as does it nowadays.2. As to the conservation treatment, the materials were comparatively good and so they employed general tank washing method with special neutrality liquid soap(made by Lab, of Household Products, Pacific R & D Center) for cleaning imbrued matrials on the clothes. After cleaning and drying naturally at a shade place, remains put into apaulowania tree box were fumigated by mixed gas (M. B. + E. O.) for prevention of damages from fungi and insects.3. Desirable environment control for scientific conservation of such kinds of cellulose textiles is to be illuminated at below 50Lux, temperature 16-18℃, relative humidity 45-60%($\pm$4%) and removed the dust. For the prevention of the damaging fungi and insects, it is desirable to fumigate by mixed gas (M.B.+E.O.) once a year.

• Hwankyungkyoyuk
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• v.9 no.1
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• pp.58-71
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• 1996

The purpose of this study was to investigate the rural housewives' recognition and practice on environmental preservation. The subjects of this study were 300 rural housewives living in Chung-buk province. Questionaires were distributed to them during a week from August $25^{th}$ to August $31^{th}$ in 1995. Major findings were as follows: 1. The saved water quite well in washing their faces and the dishes compared with urban housewives, but they did not save water so well in using the lavatory. They used synthetic detergent, one of water pollutants, more often than natural soaps in shampooing and laundering. In addition, they did not use a measuring cup. It resulted in the waste of detergent and aggravation of water pollution. 2. Food waste was disposed of properly, but used batteries were not collected separately. A disposable vinyl bag was more commonly used than a reusable shopping basket. The reason for not using a shopping basket was bothering or uncustomary. Since most of them did not know refillable products of goods with environmental mark, they did not use those. Therefore, housewives should be educated in order to prevent soil pollution. 3. The use of spry-type pesticide and hair treatment, one of air pollutants, was wide-spread among them. They hardly recognized and practiced saving of electric power when they used household electric appliances. 4. The major source of environmental knowledge was mass media like TV of radio. Many of them did not know the practical ways to solve the environmental education program. In conclusion, low level of recognition and practice of rural housewives on environmental preservation indicated that a systematic environmental education program should be developed and implemented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.271-277
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• 2003

Recently as the environmental noise getting influential social problem, it is the fact that the demand on noise reduction increases with the advance of the standard of living. Therefore increasing the interest on the noise in common, it is eagerly demanded that the endeavour for reducing the noise of the rotating machinery, especially the machinery related a flowing including the household electric products, which is pointed out the primary noise source in environment. As proceeding study for fan noise, theory of fan noise property is arranged and this control method is shown. Blade passage noise of total noise spectrum. Thus in the aspect of noise reduction, noise source and identification of noise radiation characteristics of axial flow fan are demanded in detail. The sound source is analyzed by using sound pressure and sound intensity. In that time, synchronization of axial flow fan using optical sensor is executed, and to identify the location of exact noise source in the fan profile determination of recording time is proposed. In the rotating of tan, it is explained that the location of noise source exists in and by the directivity, the noise radiation pattern of axial flow fan is determined and the flow of sound is visualized in the figure of contour mapping.

• Journal of dental hygiene science
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• v.20 no.3
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• pp.178-186
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• 2020

Background: The purpose of this study was to evaluate the association between metabolic syndrome and periodontal disease in Korean adults. Methods: This study analyzed the screening data of 12,686 adults aged ≥19 years, including demographic characteristics, lifestyle habits, and each component of metabolic syndrome, obtained from the sixth Korea National Health and Nutrition Examination Survey database. Periodontal health status was measured by the community periodontal index. Subjects with three or more risk factors were considered as having metabolic syndrome. The Rao-Scott chi-square test was performed to assess the relationships between demographic characteristics, lifestyle habits, components of metabolic syndrome, and periodontal disease. Logistic regression analysis was performed based on the complex sample to evaluate the relationship between metabolic syndrome and periodontal disease. Results: The prevalence of periodontal disease was higher among the subjects with advancing age, lower average household income and education level, those working in production, residents of eup-myeon areas, in past or current smoker, those with excessive alcohol consumption habit in a week, and reduced brushing frequency and the use of oral care products (p<0.001). Each component of metabolic syndrome was associated with higher prevalence of periodontitis in the subjects with abnormal than in those with normal levels (p<0.001). The prevalence of periodontal disease in subjects with metabolic syndrome was approximately 1.443 times higher than that in normal subjects (odds ratio,1.443; p<0.001). Conclusion: This study confirmed the association between metabolic syndrome and periodontitis in Korean adults, and further studies will be needed to determine the causal relationship between the two conditions.

• International Commerce and Information Review
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• v.19 no.4
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• pp.3-28
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• 2017

This study examined factors, such as benefit perception, risk perception, product, and website, which affect consumer attitude toward overseas direct purchase. To achieve this, 298 Korean consumers who have experienced overseas direct purchasing were analyzed. The results show that delivery risk and product risk were the most influential determinants of the level of trust level in overseas direct purchase sites. In addition, the results of this study confirm that the level of trust in overseas direct purchase sites has a strong influence on both the intention to recommend and the intention to continue patronizing the site. Moreover, this study conducted a mean difference analysis according to the types of overseas direct purchases (overseas direct delivery, overseas purchasing agency, and overseas delivery agency) and product categories (clothes, food and beverage products, and household appliances). This study lists various practical implications that can be applied to each overseas direct purchase service by firm and consumer characteristics.

• Journal of Forest and Environmental Science
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• v.28 no.2
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• pp.84-96
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• 2012

A special type of indigenous knowledge on plants utilization and farming system was explored by the Garo tribe community in the North-East region of Bangladesh, which correspond to the severe dependence on homestead forest. Results show that the Garo are totally dependent on the natural resources and that the extent of their dependency is faithfully reflected in their ethno-botanical knowledge. Dependencies that the study addressed focused on various aspects of food, fruit, energy, timber and health care on plants products. Garo tribe community in Bangladesh followed agrosilvipastoral system in their homesteads. They have indigenous hunting procedure to trap the animal in the forest. A total of 9 foods, 15 fruits, 12 energy-producing and 11 timber species was found and recorded that the Garo used in their daily life. Moreover, Garo used 23 medicinal plants species and have vast indigenous knowledge about using herbal medicine in daily health care practices. The Garo women do mostly the household activities, managing homestead forest and helping agricultural field where men perform all hard working activities like ploughing, cutting trees, digging the soil, preparation of horticultural and agricultural land, hunting, etc. The overall quality of life of the Garo could be considerably upgraded if ethno-botanical issues and their own indigenous knowledge will complement with scientific knowledge. The findings of the study conclude that the conservation of the indigenous knowledge of the Garo tribe related to plants utilization can also be turned to good account in forest conservation and is an important tool in this tribal area of Bangladesh.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.155-161
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• 2015

Radon is a naturally occurring radioactive gas and a major indoor contribution of exposure to ionizing radiation in dwellings. $^{222}Rn$ is a health hazard gas what is responsible for thousand lung cancer deaths every year. In this study, indoor radon concentrations present in thirty representative houses in Mahallat city, Iran, were determined in order to estimate lung cancer risk associated with residential radon exposure. Long-term passive method, using CR-39, was used to measure the radon concentration. The results showed an association between the age of the dwellings and the indoor radon concentration that was found, in that the concentration of radon tended to increase as the age of the dwelling also increased. The indoor radon concentrations were calculated to be within the range of $23{\pm}2$ to $350{\pm}26Bq{\cdot}m^{-3}$, with an average of $158Bq{\cdot}m^{-3}$. The annual effective dose from inhaled radon and its decay products was calculated between $0.8{\pm}0.1$ and $12.3{\pm}0.9mSv{\cdot}y^{-1}$, with an average of $5.5mSv{\cdot}y^{-1}$. By taking into consideration the EPA recommendation and ICRP statement, the average annual risk of lung cancer from inhaled radon was calculated as 0.09%, 0.06%, 0.01%, and 0.03% for current smokers (CS), those who had ever smoked (ES), never smokers (NS) and the general population, respectively.