• Korean Journal of Remote Sensing
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• v.20 no.5
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• pp.289-305
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• 2004

Atmospheric correction of Landsat Visible and Near Infrared imagery (VIS/NIR) over aquatic environment is more demanding than over land because the signal from the water column is small and it carries immense information about biogeochemical variables in the ocean. This paper introduces two methods, a modified dark-pixel substraction technique (path--extraction) and our spectral shape matching method (SSMM), for the correction of the atmospheric effects in the Landsat VIS/NIR imagery in relation to the retrieval of meaningful information about the ocean color, especially from Case-2 waters (Morel and Prieur, 1977) around Korean peninsula. The results of these methods are compared with the classical atmospheric correction approaches based on the 6S radiative transfer model and standard SeaWiFS atmospheric algorithm. The atmospheric correction scheme using 6S radiative transfer code assumes a standard atmosphere with constant aerosol loading and a uniform, Lambertian surface, while the path-extraction assumes that the total radiance (L/sub TOA/) of a pixel of the black ocean (referred by Antoine and Morel, 1999) in a given image is considered as the path signal, which remains constant over, at least, the sub scene of Landsat VIS/NIR imagery. The assumption of SSMM is nearly similar, but it extracts the path signal from the L/sub TOA/ by matching-up the in-situ data of water-leaving radiance, for typical clear and turbid waters, and extrapolate it to be the spatially homogeneous contribution of the scattered signal after complex interaction of light with atmospheric aerosols and Raleigh particles, and direct reflection of light on the sea surface. The overall shape and magnitude of radiance or reflectance spectra of the atmospherically corrected Landsat VIS/NIR imagery by SSMM appears to have good agreement with the in-situ spectra collected for clear and turbid waters, while path-extraction over turbid waters though often reproduces in-situ spectra, but yields significant errors for clear waters due to the invalid assumption of zero water-leaving radiance for the black ocean pixels. Because of the standard atmosphere with constant aerosols and models adopted in 6S radiative transfer code, a large error is possible between the retrieved and in-situ spectra. The efficiency of spectral shape matching has also been explored, using SeaWiFS imagery for turbid waters and compared with that of the standard SeaWiFS atmospheric correction algorithm, which falls in highly turbid waters, due to the assumption that values of water-leaving radiance in the two NIR bands are negligible to enable retrieval of aerosol reflectance in the correction of ocean color imagery. Validation suggests that accurate the retrieval of water-leaving radiance is not feasible with the invalid assumption of the classical algorithms, but is feasible with SSMM.

• Journal of the Korean Society of Food Culture
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• v.14 no.2
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• pp.139-146
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• 1999

This study was to investigate the consumption patterns of fast food in small city. The survey was conducted by questionnaires from March to April in 1997. The object was 500 men and women who were in their teens through fifties and living in Kimchen and Sangju city. A total of 444 subjects(88.8%) excluding incomplete answer were analyzed, all statistical data analysis were conducted using the $SAS/PC^+$. 1. The reason why people go to fast food restaurants are quickness, a convenient place, good taste, low prices, good service, and good atmosphere. There was significant correlation with each element with one exception between taste and prices. 2. On the question about the fast food which was eaten most frequently, responded hamburger to 39.86%, noodles to 29.50%, chicken to 16.67%, pizza to 10.36% and the others to 3.60%. And female, teens and twenties ate hamburger more often and another groups ate noodles more often. 3. The standard of choosing fast food restaurants was taste, prices, sanitation, atmosphere and service. There was significant correlation with exception between taste and prices, sanitation and service, atmosphere and service. 4. About propriety of fast food serving size as one meal, it was not enough portion for female and 40s. 5. The awareness that eating foreign-made food was not right, was significant difference among age groups, but not sex. 6. Customers was discontented with sanitation, price and service. There was also significant correlation with each element. 7. The frequency of eating fast food was 1-2 times/a month(35.36%), 3-5 times/a month(31.31%), 5-10 times/a month(18.24%), hardly using(11.04%), 10-20 times/a month(2.70%), over 20 times/a month(1.35%). There was significant difference among sex and age groups.

• Atmosphere
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• v.29 no.2
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• pp.213-218
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• 2019

A valuation of air pollution is critical for relevant policy-making for the public and research direction. This study conducted a willingness-to-pay (WTP) survey using contingent valuation method (CVM) in Seoul Korea. In detail, this study puts an emphasis on its temporal changes referred on two surveys conducted in 2014 and 2019. In reference to the previous studies in 2002, our survey indicated that the public awareness of air pollution and interests on its sources and solutions increased noticeably. Our survey showed that WTP increased significantly from 2588 to 4827 and 8240 Korean Won $month^{-1}$ in 2002, 2014, and 2019, respectively. Moreover, the percentage of respondents to pay the WTP also increased from 48% to 68% and 79% in 2002, 2014, and 2019, respectively. Our analysis based on the number of Google search on particulate matters (PMs) strongly suggests that such the noticeable increases of the public attention to air pollution is well accorded with the moment of the announcement of a standard for ultra-fine particles and the start of PM prediction in late 2013. But the Google search rate grew about 16.7 times in 2009 compared to 2014, which is much larger than the growth rate of interest and WTP between 2014 and 2019. Our results shed light on policy decision for the right person in the right place on the right time in the era of air pollution.

• Journal of Environmental Science International
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• v.27 no.12
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• pp.1169-1178
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• 2018

Two man-made carbon emissions, fossil fuel emissions and land use emissions, have been perturbing naturally occurring global carbon cycle. These emitted carbons will eventually be deposited into the atmosphere, the terrestrial biosphere, the soil, and the ocean. In this study, Simple Global Carbon Model (SGCM) was used to simulate global carbon cycle and to estimate global carbon budget. For the model input, fossil fuel emissions and land use emissions were taken from the literature. Unlike fossil fuel use, land use emissions were highly uncertain. Therefore land use emission inputs were adjusted within an uncertainty range suggested in the literature. Simulated atmospheric $CO_2$ concentrations were well fitted to observations with a standard error of 0.06 ppm. Moreover, simulated carbon budgets in the ocean and terrestrial biosphere were shown to be reasonable compared to the literature values, which have considerable uncertainties. Simulation results show that with increasing fossil fuel emissions, the ratios of carbon partitioning to the atmosphere and the terrestrial biosphere have increased from 42% and 24% in the year 1958 to 50% and 30% in the year 2016 respectively, while that to the ocean has decreased from 34% in the year 1958 to 20% in the year 2016. This finding indicates that if the current emission trend continues, the atmospheric carbon partitioning ratio might be continuously increasing and thereby the atmospheric $CO_2$ concentrations might be increasing much faster. Among the total emissions of 399 gigatons of carbon (GtC) from fossil fuel use and land use during the simulation period (between 1960 and 2016), 189 GtC were reallocated to the atmosphere (47%), 107 GtC to the terrestrial biosphere (27%), and 103GtC to the ocean (26%). The net terrestrial biospheric carbon accumulation (terrestrial biospheric allocations minus land use emissions) showed positive 46 GtC. In other words, the terrestrial biosphere has been accumulating carbon, although land use emission has been depleting carbon in the terrestrial biosphere.

• Journal of agricultural medicine and community health
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• v.26 no.1
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• pp.81-103
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• 2001

This study was conducted to identify the health behavior of middle-aged rural women and the factors that have an effect on them. For the purpose of the study, examinations were made from March 01, 2000 to March 31, 2000 with 468 women aged 40 to 64 out of 2,263 people whom four Primary Health Posts located in Yechon County, Kyongsangbuk-do Province, are in charge of. The results are summarized as follows. 17.5% of the subjects responded that the extent of their own interest in health were high. For the subjects having a chronic disease, a nuclear family, or an open family atmosphere, the extent appeared to be relatively higher, 15.4% responded that the extent of family's interest in their health was high. It was significantly high if the extent of education was high or if the family atmosphere was open. The subjects' average score of self-efficacy was 49.9 out of 68. The score significantly varied depending on religion, education, living together with a spouse or not, and the extent of the subjects' interest in health. The family pattern, family atmosphere, family's interest in the subjects' health were the variables that significantly influenced the self-efficacy. The average score of family function was 5.51 out of 10. The score significantly varies depending on age, education, occupation, financial status, the extent of the subjects' own interest in health, family atmosphere and family's interest in the subjects' health. In the practice of health behavior, the nonsmoking rate was 89.5%, the nondrinking rate 63.0%, the rate of exercising practice 6.6%, the rate of normal sleeping 75.6%, the rate of eating breakfast 91.7%, the rate of not eating between meals 18.2%, and the standard BMI 69.2%. In the frequency of health behavior, the subjects with the Breslow Index of 0-3, 4-5 and 6-7 accounted for 4.5%, 53.2%, and 42.3%, respectively. The average score of health behavior was 5.20 out of 7, in which significant variables were living together with a spouse or not, financial status, absence or presence of a chronic disease, and family atmosphere. In the multiple regression analysis with health behavior as a dependent variable, it was shown that living together with a spouse or not, financial status, and family atmosphere were the significantly substantial variables. The subjects were found to do health behavior well if they had not a spouse, a good financial status, or an open family atmosphere. They were also found to do health behavior well if the extent of self-efficacy was high or if the extent of family function was low, but these were not the significant variables. It is needed to develop a standard measuring tool fit for our environment and perform more studies in the future because the measuring tool used in this study was a tool developed in a foreign county. In promoting community health projects, it is required not to provide all community people with a uniform health program but to identify the health behavior of individuals and other variables such as living together with a spouse or not, financial status and family atmosphere before arranging for a proper health program.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.491-499
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• 2008

It is really urgent to develop wastewater treatment system which is economically efficient, occupies small area for buildup, can be easily operated, discharges small amount of sludge due to the more strict water quality standard, the expensive water and energy cost and so on. This study on treatment of wastewater including nonbiodegadable materials using white-rot fungus biofilm were designed to investigate the submerged type of biofilm, hydraulic retention times, recycle rates, and module turning times. Removal efficiencies of fully exposed biofilm type in atmosphere are similar to submerged biofilm of aeration type. The optimum conditions of white-rot fungus biofilm of fully exposed type in atmosphere are HRT 3$\sim$4 hr, recycle rate 6$\sim$10 Q, module turning times 0.5$\sim$2 times/min. At this time, removal efficiencies of organics were COD$_{Cr}$ 65.0$\sim$69.9%, NBDCOD 70.4$\sim$72.7%, BOD$_5$ 88.8$\sim$90.1%, SS 84.2$\sim$90.4%. Moreover average effluent concentration of BOD$_5$(8.9 mg/L) satisfied water quality standard of heavy water(BOD$_5$ less than 10 mg/L) but concentration of NBDCOD(29.6 mg/L) was higher than water quality standard of heavy water(NBDCOD less than 20 mg/L).

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.331-341
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• 2018

Hazardous air pollutants(HAPs) in the atmosphere are regulated as major air pollutants in Korea by the Air Pollution Control Act. In order to manage and control HAPs, accurate standards, which are traceable to the International System of Units(SI), are required. In this study, primary standard gas mixtures(PSMs) of volatile organic compounds(VOCs) which are specified as HAPs were developed at $1{\mu}mol/mol$ levels. The selected fourteen VOCs include Benzene, Toluene, Ethylbenzene, m-Xylene, Styrene, o-Xylene, Chloroform, 1,1,2-Trichloroethane, Trichloroethylene, Tetrachloroethylene, 1,1-Dichloroethane, Carbon tetrachloride, 1,3-Butadiene, and Dichloromethane. The HAPs PSMs were gravimetrically prepared in aluminum cylinders and their consistency was verified within the relative expanded uncertainty of 0.71% (k=2). Potential adsorption loss onto the internal surface of cylinders was estimated by cylinder-to-cylinder division method. No adsorption loss was observed within the uncerainty of 0.53%. The long-term stability of the HAPs PSMs was evaluated comparing with freshly prepared HAPs PSMs. The HAPs PSMs were stable for one year within the uncertainty of 0.38%. The final uncertainty of the PSMs was determined by combining the preparation uncertainty, verification uncertainty, and stability uncertainty. Finally, traceable and stable HAPs PSMs at $1{\mu}mol/mol$ levels were developed with the uncertainty of less than 0.76% in high-pressure aluminum cylinders.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.471-478
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• 2013

PURPOSE. The aim of the study was to evaluate the effect of annealing on the nanostructure and hardness of Co-Cr metal ceramic samples that were fabricated with a direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS. Five groups of Co-Cr dental alloy samples were manufactured in a rectangular form measuring $4{\times}2{\times}2$ mm. Samples fabricated by a conventional casting technique (Group I) and prefabricated milling blanks (Group II) were examined as conventional technique groups. The DMLS samples were randomly divided into three groups as not annealed (Group III), annealed in argon atmosphere (Group IV), or annealed in oxygen atmosphere (Group V). The nanostructure was examined with the small-angle X-ray scattering method. The Rockwell hardness test was used to measure the hardness changes in each group, and the means and standard deviations were statistically analyzed by one-way ANOVA for comparison of continuous variables and Tukey's HSD test was used for post hoc analysis. P values of <.05 were accepted as statistically significant. RESULTS. The general nanostructures of the samples were composed of small spherical entities stacked atop one another in dendritic form. All groups also displayed different hardness values depending on the manufacturing technique. The annealing procedure and environment directly affected both the nanostructure and hardness of the Co-Cr alloy. Group III exhibited a non-homogeneous structure and increased hardness ($48.16{\pm}3.02$ HRC) because the annealing process was incomplete and the inner stress was not relieved. Annealing in argon atmosphere of Group IV not only relieved the inner stresses but also decreased the hardness ($27.40{\pm}3.98$ HRC). The results of fitting function presented that Group IV was the most homogeneous product as the minimum bilayer thickness was measured (7.11 ${\AA}$). CONCLUSION. After the manufacturing with DMLS technique, annealing in argon atmosphere is an essential process for Co-Cr metal ceramic substructures. The dentists should be familiar with the materials that are used in clinic for prosthodontics treatments.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.684-696
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• 2004

Using six preservice teachers as subjects, this was purpose to research about concepts in understanding carbon cycle, which of concepts were related to the conception of the system, and finally whether or not the systems thinking was sufficiently around carbon cycle. To achieve this study purpose , an instrument related to carbon cycle was developed and administered to the six teachers. The study found that a total of 42 conceptions within the system were concepts related to carbon cycle. The consisted of 15 conceptions in atmosphere, 11 in atmosphere 9 in hydrosphere, and 7 in lithosphere. In aspect of applying the system thinking, 4 subjects who couldn't compose the feedback loop in their causal map failed to apply this type of thinking. The other two who applied systems thinking had 2 and 1 feedback loop each, in their causal maps. But, one of the feedback loop from the subject who made two was based on unscientific reasoning. As a result, the subjects had lower understanding of concepts related to carbon cycle in lithosphere than in atmosphere, atmosphere, and hydrosphere. Futhermore, the subjects' application of the earth systems thinking on carbon was at a low standard.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.36-42
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• 1982

Filters were evaluated to use in the collection of ammonia and ammonium salts in the atmosphere. Ammonia from standard gas generator was collected on a glass fiber filter impregnated with a mixture of 3% boric acid and 25% glycerin. The collection efficiency by the impregnated filter was 96.4${\pm}$2.15% in pH control method and 97.4${\pm}$1.06% in the atmosphere for five measurements, respectively. Adsorption and desorption of gaseous ammonia were compared using three commercially available filters; glass fiber, quartz fiber and polycarbonate filters. Both glass and quartz fiber filters indicated some loss of ammonium salts and adsorption of ammonia, respectively. However, polycarbonate filter was found to be satisfactory for the collection of ammonium salts in the atmosphere. The minimum measurable concentration of ammonia was 0.83ppb (ca. 0.63${\mu}g$/$m^3$) by spectrophotometry of the indophenol method for the sample collected by 47mm${\phi}$ filter(20l/min, 60min). The sensitivity of the present method is about 20 folds higher than that of conventional method of bubbler collection followed by spectrophotometry, so that this method makes it possible to measure thevariation of ammoniacal concentrations in the atmosphere for a short time period of about 60 min.