• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.69.1-69.1
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• 2013

We describe a survey of quasars in the early universe beyond z=5, which is one of the main sciences of the Infrared Medium-deep Survey (IMS) performed by the Center for the Exploration of the Origin of the Universe (CEOU). We use multi-wavelength archival data such as SDSS, CFHTLS, UKIDSS, and SWIRE, which provide deep images over wide areas sufficient enough for searching high redshift quasars. In addition, we carried out a J-band imaging survey at the United Kingdom InfraRed Telescope (UKIRT) with a depth of ~23 AB and survey area of ~100 $deg^2$, which makes IMS the most suitable survey for finding high redshift quasars at z~7. Also for the quasar candidates at z~5.5, we are conducting observations with the Camera for QUasars in EArly uNiverse (CQUEAN), which are efficient for selecting robust quasar candidate samples in this redshift range. We used various color-color diagrams suitable to the specific redshift ranges, which can reduce the contaminating sources such as M/L/T dwarfs, low redshift galaxies, and instrumental defects. The high redshift quasars we are confirming can provide us with clues to the growth of super massive black holes since z~7. Also by expanding the quasar sample at 5

• Journal of the Korean Society of School Health
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• v.32 no.2
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• pp.77-87
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• 2019

Purpose: This study was conducted to examine the prevalence of current smoking and the factors that influence current smoking among male high school students in Korea according to school type. Methods: Data were extracted from the Korea Youth Risk Behavior Web-Based Survey (2017) and multiple logistic regression was used based on complex sample analysis. The study sample comprised of 15,777 male high school students: 12,583 from general high schools (GHS) and 3,194 from specialized vocational high schools (SVHS). Results: The prevalence of current smoking was significantly higher in SVHS students (19.6%) compared to GHS students (12.6%). Low academic achievement, depressive symptoms, current drinking, and high household economic status were commonly associated with current smoking in male students from both school types. However, exposure to secondhand smoking at home, non-exposure to anti-smoking advertisement, exposure to tobacco advertisement, participation in smoking prevention or cessation education were related to current smoking in GHS students, while living in rural area was associated with current smoking in SVHS students. Conclusion: To reduce current smoking among male high school students, it is necessary to develop smoking prevention policies reflecting the factors associated with current smoking that are different by school type.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1423-1431
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• 2016

When the sample size in a certain domain is too small to produce adequate information, small area model with random effects is usually used. Also, if we do not consider an inherent pattern which data possess, it considerably affects inference. In this paper, we mainly focus on modeling to handle increased variation of the Current Population Survey (CPS) median income as the Internal Revenue Service (IRS) mean income increases. In a hierarchical Bayesian framework, most estimations are carried out through the Gibbs sampler while the grid method is used to generate parameters from non-standard form. Numerical study indicates that the performance of proposed model is better than that of CPS method in terms of four comparison measurements.

• Hwankyungkyoyuk
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• v.2 no.1
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• pp.5-33
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• 1991

The purpose of the study was to investigate attitudes toward to, values and expectations of environmental education of Korean students and teachers and to provide basic data and reference materials needed to development of environmental education curricula for primary and secondary schools. A review of the related literature, a series of conferences with teachers and specialists in environmental education and environmental sciences. and questionnaire survey were methods employed in this study. Survey question were developed to explore attitude and responses of primary and secondary school students and teachers on various types of issues and problems of environmental education at personal level as well as on their future prospects attitudes values and expectations with which had been dealt in this study were categorized into personal feeling on environmental issues and problems at both national and regional levels issues and problems of current environmental education pre service and in service training of teachers for environmental education instruction and so on. The sample population for the survey was selected by using the stratified cluster and random sampling techniques with respect to regional area, school level, sex and grade, The subjects used in this study were 1,633 students and 385 teachers of primary and secondary schools across the country. The results of the survey were summed up and recommendations to be considered in the revision of sixth national curricula for primary and secondary schools were also suggested.

• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.352-359
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• 2024

Environmental pollution from heavy metal ions (HMIs) is a global concern. Recently, biosorption methods using cellulose sorbents have gained popularity. The objective of this study was to assess the removal efficiency of Cu(II), Pb(II), and Hg(II) ions at low concentration levels (100-700 ppb) from aqueous solutions using three different cellulose fiber-based filter media. Sample A was pure cellulose fiber, Sample B was 10% activated carbon-cellulose fiber, and Sample C was cellulose fiber-glass fiber-30% activated carbon-20% amorphous titanium silicate (ATS). The samples were characterized by several physicochemical techniques. The porosity measurements using N₂ sorption isotherms revealed that Samples A and B are nonporous or macroporous materials, whereas the addition of 50% filler materials into the cellulose resulted in a microporous material. The Brunauer-Emmett-Teller (BET) surface area and pore volume of Sample C were found to be 320.34 m²/g and 0.162 cm³/g, respectively. The single ion batch adsorption experiments reveal that at 700 ppb initial metal ion concentration, Sample A had removal efficiencies of 7.5, 11.5, and 13.7% for Cu(II), Pb(II), and Hg(II) ions, respectively. Sample B effectively eliminated 99.6% of Cu(II) ions compared to Pb(II) (14.2%) and Hg(II) (31.9%) ions. Cu(II) (99.37%) and Pb(II) (96.3%) ions are more efficiently removed by Sample C than Hg(II) (68.2%) ions. The X-ray photoelectron spectroscopy (XPS) wild survey spectrum revealed the presence of Cu(II), Pb(II), and Hg(II) ions in HMI-adsorbed filter media. The high-resolution C1s spectra of Samples A and B reveal the presence of -C-OH and -COOH groups on their surface, which are essential for HMIs adsorption via complexation reactions. Additionally, the ATS in Sample C facilitates the adsorption of Pb(II) and Hg(II) ions through ion exchange.

• Survey Research
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• v.12 no.3
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• pp.143-172
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• 2011

The relationship between body weight and body image, an objective and subjective measure of body shape, respectively, has long been a recurrent concern in the area of medical sociology and health-related studies. This concern stems from the argument and findings in the literature indicating that the two are not necessarily likely to be strongly correlated due mostly to the fact that one's own idea or conception about his/her body shape could be pretty different from one's actual shape. This study tries to empirically address the two issues based on the analysis of a national sample survey data in Korea: to what extent body weight and body image are correlated with or deviated from each other, on the one hand, and what factors help to account for the relationship between the two, on the other. The latest(2010) national sample data of KGSS(Korean General Social Survey) is used to evaluate the issues. Results of data analysis demonstrate that body weight and image have a moderate amount of correlation, and that the correlation tends to vary to a large extent depending on a few major socio-demographic and socio-economic characteristics. Most important, the risk factor analysis attempted in this study could identify several salient risk factors, which include gender, age, chronic diseases, smoking, physical exercises, and medical checkup. To be precise, those who may be best characterized as particularly risky to weight gains are females, who are in their 20's, who have chronic diseases, non-smokers, who exercise regularly, and who conduct medical checkups on a regular basis. To extrapolate, the findings suggest that the most typically risky kinds of individuals in Korea are "young women who care very much for their health." The findings are interpreted and discussed with suggesting a recommendation for further studies.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.87-87
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• 2013

Sample concentration and purification processes are essential in the bio-analytical and pharmaceutical fields because most bio samples or media are extremely sophisticated. To concentrate and purify specific substances, passive membrane type filters have been utilized, which is driven by size or charge differences between target and others. The traditional and representative method to identify nucleic acid sequences in the complex biosample is gel electrophoresis, which has been worked by size and net charge of molecules. The adsorption phenomena have been also utilized to concentrate and purify biomolecules. This adsorption of biomolecule can be controlled under specific salts and surfaces as well as surface area. To utilize the differences of physical properties of molecules or bio-targets such as virus, bacteria, and cells, the nanotechnologies can be introduced in target concentration, purification, and isolation processes. In here, I'd like to briefly survey typical examples of nanobiotechnologies which are introduced in sample treatment. Also I specifically demonstrate two different simple techniques to concentrate and detect bacteria from the samples using multifunctional silica nanotube (SNT).

• Journal of Families and Better Life
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• v.27 no.1
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• pp.17-29
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• 2009

The aim of this paper is to examine the demographic characteristics and the attitude about marriage and the policy of the unmarried male farmers. The contents of research are two folds: 1) Analyze the marriage related demographic statistics of rural area using the data from Korea Statistical Information System and marriage statistics in 2007, 2) survey analyses of the attitude toward marriage, perception and needs of international marriage, and related policies from data of 170 unmarried male farmers. The results are as follows: first, the marriage rates among over 15 years old of the rural area is 78.2% for men while 1.8% for 20${\sim}$24 age group and 9.3% for 25${\sim}$29 age group. The marriage rates in this area are varied by region especially low in Kyunggido & Jejudo. Second, the portion of international marriages of Korean male farmers with foreign partner are 11% among all international marriages of Korean males. There are high rates of male farmers' international marriage in Junranamdo and Kyungsangbukdo which are characterized by low level of urbanization, low inter-city mobility, low rates of age group of under 15 years and high portion of over age 65. Finally, the survey results showed that 83% of the sample lived with their parents; event though 80% of farmers think marriage is necessary, 60% had no plan of marriage because of difficulties to meet marriage partners and of lacking economic resources; they showed a negative perception toward the handicapped, foreigners, Afro-Americans, Westerners and divorcees as a marriage partner; they also showed negative recognition to international marriage because of observed problems of neighboring international marriage couples and concerns of cultural differences; they pointed out that the government's concern about improving quality of the environment of the rural area and reforming the international marriage aid law was the most necessary. The discussion and the future research directions were added.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.72-78
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• 2001

In this study, high spatial resolution of IKONOS 1m image and Red(0.63~0.69) band, NIR(0.76~0.90) band in 4m image, which are the same wavelength range as Landsat TM band 3, 4, were used for extraction of the front areas of B. Xylophilus in Geuje island where is located in southern part of Korea. Moreover, since they have higher spatial resolutions than Landsat TM, they have been used for lots of studies in the field of forest and vegetation. In the results, it was validated by GPS field survey, spectral histogram analysis of IKONOS NIR band was significant available method for extracting the front areas of B. Xylophilus. In this study, 15 points were verified as real damaged trees of 22 sample points extracted from GPS field survey. This study was not only extracted the damaged trees by B. Xylophilus but also suggested the possibility of using IKONOS images for the study on the forest damages by any disease and insect pests.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.20-27
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• 2008

This study was conducted to investigate the influence of thinning and pruning on characteristics of forest stand, mesopore ratio and soil water content at the Pinus koraiensis stands in Gwangneung, Gyeonggido. The Pinus koraiensis had been planted in 1976 and thinning and pruning were carried out in 1996. A sample area survey was conducted at experimental plots (thinned and unthinned) in 1998 and 2005, and mesopore ratio and soil water content have been monitored from 2000 to present. Average tree height of the thinned plot increased from 10.9m to 13.2m and from 10.3m to 12.8m for the unthinned plot. Average D.B.H of the thinned plot increased from 15.9cm to 21.1cm and from 14.5cm to 16.7cm for the unthinned plot during the period 1998-2005. Crown density at the thinned plot increased from 81.5% to 95.0% and from 89.5% to 95.0% for the unthinned plot during the period 1998-2005. Mesopore ratio (pF2.7) of A layer soil at the thinned plot was 40.1% while that of the unthinned plot was 37.3%. Changes of mesopore ratio at unthinned plot were not associated with stand age, but those at thinned plot had increased and then decreased, showing declining of the practice effect. Average soil water content at the thinned plot were 23.7% and 22.4% for the unthinned plot. Soil watercontents at both plots have been increased with increase in stand age. But the difference of soil watercontent at each plot has been decreased, especially at the depth of 10cm.