• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.119-119
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• 2011

This study examined the synthesis of large area graphene and the change of its characteristics depending on the ratio of CH4/H2 by using the thermal CVD methods and performed the experiments to control the electron-hole conduction and Dirac-point of graphene by using chemical doping methods. Firstly, with regard to the characteristics of the large area graphene depending on the ratio of CH4/H2, hydrophobic characteristics of the graphene changed to hydrophilic characteristics as the ratio of CH4/H2 reduces. The angle of contact also increased to 78$^{\circ}$ from 58$^{\circ}$. According to the results of Raman spectroscopy showing the degree of defect, the ratio of I(D)/I(G) increases to 0.42% from 0.25% and the surface resistance also increased to 950 ${\Omega}$ from 750 ${\Omega}$/sq. As for the graphene synthesis at the high temperature of 1,000$^{\circ}$ by using CH4/H2 in a Cu-Foil, the possibility of graphene formation was determined as a function of the ratio of H2 included in the fixed quantity of CH4 as per specifications of every equipment. It was observed that the excessive amount of H2 prevented graphene from forming, as extra H-atoms and molecules activated the reaction to C-bond of graphene. Secondly, in the experiment for the electron-hole conduction and the Dirac-point of graphene using the chemical doping method, the shift of Dirac-point and the change in the electron-hole conduction were observed for both the N-type (PEI) and the P-type (Diazonium) dopings. The ID-VG results show that, for the N-type (PEI) doped graphene, Dirac-point shifted to the left (-voltage direction) by 90V at an hour and by 130 V at 2 hours respectively, compared to the pristine graphene. Carrier mobility was also reduced by 1,600 cm2/Vs (1 hour) and 1,100 cm2/Vs (2 hours), compared to the maximum hole mobility of the pristine graphene.

• Korean Journal of Materials Research
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• v.16 no.4
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• pp.225-230
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• 2006

Nanoimprint lithography (NIL) is a novel method of fabricating nanometer scale patterns. It is a simple process with low cost, high throughput and resolution. NIL creates patterns by mechanical deformation of an imprint resist and physical contact process. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting process. Stiction between the resist and the stamp is resulted from this physical contact process. Stiction issue is more important in the stamps including narrow pattern size and wide area. Therefore, the antistiction layer coating is very effective to prevent this problem and ensure successful NIL. In this paper, an antistiction layer was deposited and characterized by PECVD (plasma enhanced chemical vapor deposition) method for metal stamps. Deposition rates of an antistiction layer on Si and Ni substrates were in proportion to deposited time and 3.4 nm/min and 2.5 nm/min, respectively. A 50 nm thick antistiction layer showed 90% relative transmittance at 365 nm wavelength. Contact angle result showed good hydrophobicity over 105 degree. $CF_2$ and $CF_3$ peaks were founded in ATR-FTIR analysis. The thicknesses and the contact angle of a 50 nm thick antistiction film were slightly changed during chemical resistance test using acetone and sulfuric acid. To evaluate the deposited antistiction layer, a 50 nm thick film was coated on a stainless steel stamp made by wet etching process. A PMMA substrate was successfully imprinting without pattern degradations by the stainless steel stamp with an antistiction layer. The test result shows that antistiction layer coating is very effective for NIL.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.4
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• pp.65-73
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• 2018

Although the road construction in forest is increasing and there is a need for development ecological restoration on deforest area, no consideration has been given to individual trees in there. This study analyzed aerial photographs of deforest area before and after road construction for determining the degree of forest destruction by extracting individual trees. Study area was selected in the sites where are damaged by road construction in GongJu-si, YuSung-gu, and YeongDong-gun. The aerial photograph taken 1979 before construction is panchromatic image of 80cm in GSD (Ground Sample Distance) and other photograph taken 2016 after construction is multi-spectral image of 10cm in GSD. In order to minimize the difference of GSD, we conducted image re-sampling process for setting to same GSD for the two photographs. After that we carried out visual interpretation method for determining to change of individual tree. The result found that for GongJu-si of the number of individual tree was 1,014 in 1979 and 886 in 2016, which decreased by 128 (12.6%) and the average width of those decreased from 5.77m to 5.75m by 0.47%. In case of YoungDong-gun, the number of it was 761 in 1979 and 746 in 2016, which decreased by 2.0% and the average width of it decreased from 8.99mm to 8.90m by 1.1%. Lastly in case of YuSung-gu, the number of it was 1,578 in 1979 and 988 in 2016, which decreased by 37.4% and the average width of it decreased from 7.09m to 6.65m by 6.21%. these result imply that road construction causes destruction of forests. Since there are limitations such as errors due to researcher, it is necessary to construct a quantitative analysis method for the change of the deforest area. It is need to study the method of extracting individual tree in deforest area more accurately using high-resolution image of GSD 10cm or more as well. This study can be used as a basic data for the ecological restoration of the deforest area considering characteristics of individual tree such as height, diameter at breast height, and biomass.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.4
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• pp.220-232
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• 2012

In this paper, we investigate the correlation result due to the problems of delay tracking and fringe rotation module in the VCS(VLBI Correlation Subsystem). The VCS, FX-type correlator, adopts the delay tracking and fringe rotation module in order to compensate the delay change and fringe phase of wave signal from the radio source by Doppler's effect. The phase of observed data is also compensated by means of delay tracking and fringe rotation in the correlator, but we confirmed that the phase is unstable by applying long integration period of AIPS(Astronomical Image Processing System) rather than correlator. And the delay value of observed data has the errors of several tens nanoseconds than normal case at the analysis of correlation result. In addition, we found that the phase of correlation results is not connected as the unit of FFT-segment because the initial fringe phase at the fringe rotation module is not correctly determined. In this paper, in order to solve these problems, the original direction of 90 degree phase jump is reversely modified when the bit-shift occurred at the delay tracking. And the initial fringe phase at the fringe rotation module is correctly modified by using the initial phase of observed data. In addition, the parameter calculation module was abnormally operated as designed in the fringe rotation. So, the logical program by the VCS is modified so as to calculate the parameters correctly. Through the experiments of correlation processing over the above problems, the modified proposal algorithm is adequately corrected to the data analysis results, so that the experimental results make it clear for us to operate the developed VCS hardware correlator normally.

• Economic and Environmental Geology
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• v.21 no.2
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• pp.149-164
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• 1988

Electrum-sulfide mineralization of the Samgwang and Sobo mines of the Cheongyang Au-Ag area was deposited in two stages of quartz and calcite veins that fill fault zones in granite gneiss. Radiometric dating indicates that mineralization is Early Cretaceous age (127 Ma). Fluid inclusion and sulfur isotope data show that ore mineralization was deposited at temperatures between $340^{\circ}$ and $180^{\circ}C$ from fluids with salinities of 1 to 8 wt. % equiv. NaCl and a ${\delta}^{34}S_{{\sum}S}$ value of 2 to 5 per mil. Evidence of fluid boiling (and $CO_2$ effervescence) indicates a range of pressures from < 200 to $\approx$ 700 bars, corresponding to depths of ${\approx}1.5{\pm}0.3\;km$ in a hydrothermal system which alternated from lithostatic toward hydrostatic conditions. Au-Ag deposition was likely a result of boiling coupled with cooling. Meaured and calculated hydrogen and oxygen isotope values of ore-forming fluids indicate a significant meteoric water component, approaching unexchanged paleometeoric water values. Comparison of these values with those of other Korean Au-Ag deposits reveals a relationship among depth, Au/Ag ratio and degree of water-rock interaction. All investigated Korean Jurassic and Cretaceous gold-silver-bearing deposits have fluids which are dominantly evolved meteoric waters, but only deeper systems (${\geq}1.5\;km$) are exclusively gold-rich.

• Journal of Families and Better Life
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• v.26 no.3
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• pp.37-52
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• 2008

The purpose of this study was to provide the valid data about residential-linked pension insurance development. The development was a part of national housing projects, which was an incentive for rural living of retired people, in order to relieve residential issues of elderly and revitalize rural communities by residents moving from cities. The insuring intent, decisive insuring factors and the residential service demand degree of people preparing retirement were analyzed. Data was collected in October, 2007. 364 Sample Subjects lived in Seoul Metropolitan area. Firstly, more than 90% of respondents had intention to purchase a residential-linked pension insurance and about 50% of them necessarily desired receiving premium for moving in. This indicated that it could be developed as an insurance which helped to meet housing expenses by housing-linked system, and in the mean time, it met the original purpose of pension insurance as the pension benefit could be guaranteed for all the insurance subscribers. Secondly, the respondents, whose income and private assets were higher, were able to pay more for insurance compared to average. Therefore, It was necessary to regulate monthly insurance bill and the payment period according to asset states of insurance subscribers after establishing certain amount of total insurance payment. Thirdly, by and large, it indicated the tendency that the less they prepare for older age the later they wanted to move into the pension insurance residence. It was inferred that in the case of insufficient preparation for older age, people preferred preparing behind time by postponing move in to moving in early to enjoy retired life, due to uncertainties. lastly, the respondents understood the significance of health, medical treatment and emergency management service and these two services were preferred as essential provided services. Because of the necessity of developing residential-linked pension insurance was found to be positive, further research to find the real cost, directives for operation and institutional support for this type of pension insurance might be needed.

• The Journal of Korean Academic Society of Nursing Education
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• v.7 no.2
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• pp.333-348
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• 2001

The study was intended to investigate the degree of satisfaction and experiences of maternity nursing practice and to examine the relationships between satisfaction and experiences. Data were collected from a college located in Inchon from April 2, 2001 to October 30, 2001. A general characteristics questionnaires, questionnaire for clinical practice satisfaction and maternity nursing clinical checklist were used to measure the satisfaction and experiences of maternity nursing practice. The subject were supposed to record their clinical experience in maternity clinical practice checklist. 153 questionnaires for satisfaction of clinical practice and 178 maternity nursing clinical practice checklists used for analysis. The data were analyzed by SPSS-PC+ program. The results of this study were as follows ; 1) The mean score of satisfaction of clinical practice was 3.34(a perfect score 5) and among the 4 categorial components from the questionnaire of satisfaction the score of 'clinical practice teaching' was high(3.85) and 'clinical practice environment(2.91)' and 'clinical practice contents(2.90)' was relatively low. 2) There was significant value between place of clinical practice and clinical practice satisfaction among 7 clinical practice hospital and the most high score of clinical practice satisfaction is 3.70 and the low score is 2.91(F=7.706, p<.001). The score of delivery room was significantly higher than the OBGY room and there was significant value among the place of clinical practice(DR : F= 6.441, p<.001, OBGY room : F=7.908, p<.001). 3) In delivery room, the frequency of observation are 2.61 day, the frequency of practice are 1.33 day and in OBGY room the frequency of observation are 1.73 day, the frequency of practice are 1.31 day for 2 week of maternity clinical practice and the most frequent practice of maternity nursing care was checking vital sign. 4) There were significant relationships between the ranking score of clinical satisfaction and clinical experiences in maternity nursing practice. Based on the results, it is suggested that the satisfaction of clinical practice was related to environment of clinical practice and it is necessary to improve environment of clinical practice and make a strategies to enhance the quality of maternity clinical experience.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.31-42
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• 1990

Storage ecosystems of rough rice, brown rice and polished rice were analyzed form Feb. 1987 to Nov. 1988 to investigate structures and ecological successions in the arthropod communities as well as changes in energy of the systems. The changes in temperature of stored rice showed high degree dependence on the temperature of storage room with time lag of about four weeks. Moisture content of rough rice, brown rice and polished rice during the period were in the range of 12.7$\pm$0.4, 13.1$\pm$0.4 and 13.5$\pm$0.3%, respectively. The arthropod communities in rough rice, brown rice and polished rice were qualitatively and quantitatively different. In rough rice, dominant species changed from Leptinotus reticulatus Endlein to Liposcelisentomophilus Endlein, while in brown rice from Pyralis farinalis L. to Sitophilus oryze (L.), unidentified parasitic wasps, Anisopteromalus calandrae Howard and Tribolium castaneum Herbst and finally to S. oryzae. In polished rice, the arthropod community showed an ecological succession similar to that in brown rice except for a transient dominance of two psocidspecies. Thearthropod community in rough rice was rather simple and unstable in comparison with those in brown rice and polished rice. The 1000 kernel weight of brown rice decreased slightly during the period when the arthropods were active (summer season), while that of rough rice and polished rice remained at the similar level. However, the ash content per unit volume of brown rice as well as rough rice and polished rice showed no increase during the period.

• The Journal of the Petrological Society of Korea
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• v.23 no.4
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• pp.337-349
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• 2014

We measured rare earth element and Zr concentrations of USGS granite standard material GSP-2 and GSJ granite standard material JG-1a to clarify the effect of zircon during rare earth element analysis using ICP-MS. We also measured rare-earth element and zirconium (Zr) contents of zircon from granite by acid-digestion methods using conventional teflon vial and pressure-bomb. The results show that acid-digestion using teflon vial dissolved ca. 50% of zircon compared to pressure-bomb method. The Zr contents of JG-1a and GSP-2 gave ca 50% of reference value. However, rare-earth element abundance of JG-1a and GSP-2 were similar to those of reference values. This suggests that the decomposition degree of zircon might give a negligible effect on a petrological and geochemical interpretation using chondritenormalized REE pattern.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.236-242
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• 2011

In this present study, we investigated the anti-oxidant activity, the inhibition ability of lipid peroxidation, and the protective effect of cow pulmonary epithelium (CPAE) cells under oxidative stress using green tea and 3 types of fermented teas of Jeju Island. To compare the physiological activity of non-fermented and 3 types of fermented teas, the fermented time was controlled with 0 hr. (non fermented tea, G), 12 hrs. (20% fermented tea, F20), 17 hrs. (50% fermented tea, F50) and 24 hrs. (80% fermented tea, F80), respectively. Scavenging ability on DPPH radicals of 80 ${\mu}g/mL$ concentration of F20 was similar to that of 50 ${\mu}M$ epigallocatechin gallate (EGCG) but it was stronger than those of G, F50 and F80. All extracts tested inhibited LDL oxidation but G and F20 inhibited LDL oxidation 25~30% more than F50 and F80 at 40 ${\mu}g/mL$ concentration which was similar to that of 50 ${\mu}M$ EGCG. We observed that the CPAE cells treated with the tea extracts had a significant increase in cell viability, especially the cells under oxidative stress with 1 mM $H_2O_2$ as compared with the control group (no treatment with tea extracts). These findings suggested that all tea extracts containing fermented tea had a protective effect on oxidative stressed CPAE cells through their free radical scavenging activity. It can be concluded that F20 extracted from 20% fermented tea has the most significant antioxidative effects that inhibit lipid peroxidation and protect the CPAE cells under oxidative stress.