• Journal of dental hygiene science
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• v.12 no.6
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• pp.607-616
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• 2012

The purpose of this study was to examine the self-rated oral health status and oral health concern of 6,094 adults over the age of 19, which were both related to subjective oral health awareness, based on the second-year (2008) raw data of the 4th National Health and Nutrition Survey. 1. As for subjective oral health awareness, 49.4 percent replied they were in bad oral health when they were asked about self-rated oral health status. Regarding oral health concern, 62.6 percent answered they were sort of concerned about oral health. 2. As to oral health indexes by sociodemographic characteristics, there were statistically significant differences in oral health indexes according to gender, age, academic credential, monthly mean household income, frequency of eating between meals and toothbrushing frequency. Smoking made no statistically significant differences to oral health indexes (p<0.000). 3. Concerning self-rated oral health status by sociodemographic characteristics, no significant differences were found according to gender, age and academic credential, and there were statistically significant differences according to monthly mean household income and smoking (p<0.000), frequency of eating between meals (p<0.018), toothbrushing frequency (p<0.003). 4. In relation to oral health concern by sociodemographic characteristics, gender and smoking made no significant differences, and statistically significant differences were found according to age (p<0.003), academic credential, monthly mean household income, frequency of eating between meals and toothbrushing frequency (p<0.000). 5. In regard to the relationship between subjective oral health awareness and oral health indexes, none of the oral health indexes had a significant relationship to self-rated oral health status, and there were statistically significant differences in oral health concern according to functioning teeth index (p<0.011) and community periodontal index (p<0.017).

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.379-394
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• 2021

Purpose. In our previous studies, application of trichloroacetic acid (TCA) to gingival fibroblasts or to canine palatal soft tissue was verified to alter the expression of several genes responsible for cell cycle progression. In order to confirm this effect in a system allowing sequential release of TCA and epidermal growth factor (EGF), expression of various cell cycle genes following the application of the agents, using hydrophobically modified glycol chitosan (HGC)-based nano-controlled release system, was explored in this study. Materials and methods. HGC-based nano-controlled release system was developed followed by loading TCA and EGF. The groups were defined as the control (CON); TCA-loaded nano-controlled release system (EXP1); TCA- and EGF- individually loaded nano-controlled release system (EXP2). At 24- and 48 hr culture, expression of 37 cell cycle genes was analyzed in human gingival fibroblasts. Correlations and the influential genes were also analyzed. Results. Numerous genes such as cyclins (CCNDs), cell division cycles (CDCs), cyclin-dependent kinases (CDKs), E2F transcription factors (E2Fs), extracellular signal-regulated kinases (ERKs) and other cell cycle genes were significantly up-regulated in EXP1 and EXP2. Also, cell cycle arrest genes of E2F4, E2F5, and GADD45G were up-regulated but another cell cycle arrest gene SMAD4 was down-regulated. From the multiple regression analysis, CCNA2, CDK4, and ANAPC4 were determined as the most influential factors on the expression of ERK genes. Conclusion. Application of TCA and EGF, using the HGC-based nano-controlled sequential release system significantly up-regulated various cell cycle progression genes, leading to the possibility of regenerating oral soft tissue via application of the proposed system.

• The Journal of Engineering Geology
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• v.29 no.2
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• pp.85-97
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• 2019

It can be observed that steep slopes ($65^{\circ}$ to $80^{\circ}$) consist of rock masses were kept stable for a long time. In rock-mass slopes with similar ground condition, steeper slopes than 1 : 0.5 ($63^{\circ}$) may be applied if the discontinuities of rock-mass slope are distributed in a direction favorable to the stability of the slope. In making a decision the angle of the slope, if the preliminary rock mass conditions applicable to steep slope are quantitatively setup, they may be used as guidance in design practice. In this study, the above rock mass was defined as a good continuum rock mass and the quantitative setup criterion range was proposed using RMR, SMR and GSI classifications for the purpose of providing engineering standard for good continuum rock mass conditions. The methods of study are as follows. The stable slope at steep slopes ($65^{\circ}$ to $80^{\circ}$) for each rock type was selected as the study area, and RMR, SMR and GSI were classified to reflect the face mapping results. The results were reviewed by applying the calculated shear strength to the stable analysis of the current state of rock mass slope using the Hoek-Brown failure criterion. It is intended to verify the validity of the preliminary criterion as a rock mass condition that remains stable on a steep slope. Based on the analysis and review by the above research method, it was analyzed that a good continuum rock mass slope can be set to Basic RMR ${\geq}50$ (45 in sedimentary rock), GSI and SMR ${\geq}45$. The safety factor of the LEM is between Fs = 14.08 and 67.50 (average 32.9), and the displacement of the FEM is 0.13 to 0.64 mm (average 0.27 mm). This can be seen as a result of quantitative representation and verification of the stability of a good continuum rock mass slope that has been maintained stable for a long period of time with steep slopes ($65^{\circ}$ to $80^{\circ}$). The setup guideline for a good continuum rock mass slope will be able to establish a more detailed setup standard when the data are accumulated, and it is also a further study project. If stable even on steep slopes of 1 : 0.1 to 0.3, the upper limit of steep slopes is 1 : 0.3 with reference to the overseas design standards and report, thus giving the benefit of ensuring economic and eco-friendlyness. Also, the development of excavation technology and plantation technology and various eco-friendly slope design techniques will help overcome psychological anxiety and rapid weathering and relaxation due to steep slope construction.

• Korean Journal of Poultry Science
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• v.48 no.2
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• pp.69-80
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• 2021

We conducted a 4 × 4 diallel cross-mating test using 934 chickens from four grandparent stock lines to develop a new synthetic breed of Korean native chicken. The mean values, combining ability, and reciprocal effects on survival rate, body weight, and hen-day egg production were analyzed. In phenotypes, most chickens have yellowish-brown, reddish-brown and mixed color feathers. The average survival rate was 86.8±12.3%, with the highest in YH combination. Specific combining ability (SCA) had a greater effect on survival rate than general combining ability (GCA), and the SCA of HY combination was the highest. The 16 cross-combinations were distinctly divided into three weight groups according to their genetic characteristics. At 12 weeks of age, GCA showed a greater effect on weight than SCA, and the SCA of FH combination was the highest. The age at first egg laying was 157 days, and the crosses reached sexual maturity faster than the pure lines. The egg production rate was highest in SY at 79.5±2.1%. The GCA and SCA for hen-day egg production were similar, and the SCA was highest in the HS and FY combinations. The reciprocal effect showed that the offspring's egg production rate was high when S and Y were maternal parents in almost all combinations. In conclusion, FH and HF combinations, which have excellent growth performance, are the most desirable paternal parent stock strains, and FY, FS, HY, and SY combinations, which have excellent laying performance with moderate weight, are the preferred maternal strains.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.77-95
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• 2022

The Gonamsan gabbroic complex in the Pocheon area, northwestern region of South Korea consists of a variety types of gabbroic rocks and associated Fe-Ti oxide deposits caused by magmatic differentiation. Post-magmatic intrusions (i.e., gabbroic pegmatite and pyroxene-apatite-zircon rocks) partly intruded into the gabbroic rocks. The gabbroic pegmatite occurs in monzodiorite and oxide gabbro of the complex, intimately and spatially associated with high-grade lenticular Fe-Ti oxide mineralization. The pegmatite can be subdivided into plagioclase-amphibole and pyroxene-olivine pegmatite, in which the contact surface is sharp. The plagioclase-amphibole pegmatite comprises plagioclase and amphibole, with lesser amount of pyroxene, ilmenite, sphene, apatite, and biotite. The pegmatite shows plagioclase-amphibole intergranular texture, in which the open space formed by large plagioclase laths (An_2-26Ab_72-98Or_0-2) are infilled by amphibole. The pyroxene-olivine pegmatite is dark gray to black in color and also contains magnetite, ilmenite, spinel, apatite, and calcite as a minor component. The pyroxene (En_35-36Fs_8-9Wo₅₅) and olivine (Fo_84-85Fa_15-16) partly show a poikilitic texture defined by smaller euhedral olivine enclosed by coarser clinopyroxene. Fe-Ti oxide minerals consist mainly of magnetite and ilmenite that are found interstitially to earlier formed silicates. Subsequently, they are encompassed by reaction rim (almost of amphibole and biotite) along the boundary with surrounding silicate minerals. Under the microscope, magnetite contains a lot of oxyexsolved ilmenite (trellis type) and spinel, and thereby is weakly enriched in magnetite-compatible elements such as Ti, Al, Mg, and V. The structure and textures at the contact zone as well as mineralogical disequilibrium between gabbroic pegmatite and the host gabbroic rocks suggest that the pegmatite may form as a result of accumulation from Fe-rich melt (or liquid) that occurred somewhere rather than in situ form from the host gabbroic rock during the magmatic differentiation. Consequently, the preliminary study suggests that further study on the post-magmatic activities can not only help us improve our understanding on magmatic fractionation but also provide critical information on Fe-Ti oxide mineralization in gabbroic rocks resulting from the magmatic differentiation.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.69-81
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• 1995

This study was conducted to examine the genetic variants of the blood proteins and enzymes in beef cattle breeds, Hereford, Angus and Sharolais reared at the Daekwanryuong Branch of the National Livestock Research Institute. Genetic polymorphisms of transferrin(Tf), post-transferrin2(pTf-2), albumin(Alb), post-albumin (pAlb), ceruloplasmin(Cp), amylase-I(Am-I) and hemoglobin(Hb) in blood were analyzed by the methods of PAGE(polyacrylamide gel electrophoresis) and STAGE(starch gel electrophoresis). The results obtained from this study were summarized as follows: 1. Tf and pTf-2 locus assumed to be controlled by codominant alleles, A. $D_1$, $D_2$ and E allele for Tf, F and S allele for pTf-2. In genotype frequencies, 25% and 90% for Tf $D_1D_2$ and pTf-2 SS in Hereford, 25% and 100% for Tf $AD_1$ and pTf-2 FF in Angus, 50% for Tf $D_1D_1$ and pTf-2 FS in Sharolais were found to have the highest frequency, respectively. In gene frequencies, 0.400 and 0.900 for Tf E and pTf-2 S allele in Hereford, 0.678 and 0.607 for Tf $D_1$ and pTf-2S in Sharolais were appeared to have the highest frequency. 2. Alb and pAlb locus assumed to be controlled by codominant alleles, only A allele for Alb, F and S allele for pAlb. In genotype frequencies, 70% for pAlb SS in Hereford, 90% for pAlb FF in Angus and 57.15% for pAlb SS in Sharolais were found to have the highest frequency. In gene frequencies, 0.825 and 0.750 for pAlb S in Hereford and Charolais, 0.900 for pAlb F in Angus were found to have the highest frequency. 3. Cp and Am-I locus appeared to be controlled by two alleles, F and S allele for Cp, B and C allele for Am-I. In genotype frequencies, 100% and 65% for Cp FF and Am-I BB in Hereford, 45% and 85% for Cp FF, and Am-I CC in Angus, 50% and 64.29% for Cp FF and Am-I BC in Sharolais were found to have the highest frequency. Gene frequencies were 1,000, 0.600 and 0.750 for Cp F in Herehord, Angus and Sharolais, 0.800, 0.875 and 0.680 for Am-I B, C and C allele in Hereford, Angus and sharolais, respectively. 4. Hb locus assumed to be controlled by codominant alleles, only A allele in Hereford and Angus, A and B allele in Sharolais. Genotype frequencies were 57.14% and 42.86% for Hb AA and AB in Sharolais, and gene frequencies were 0.785 and 0.215 for Hb A and B in Sharolais.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.417-433
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• 1992

Lead-zinc-copper deposits of the Jeonheung and the Oksan mines around Euiseong area occur as hydrothermal quartz and calcite veins that crosscut Cretaceous sedimentary rocks of the Gyeongsang Basin. The mineralization occurred in three distinct stages (I, II, and III): (I) quartz-sulfides-sulfosalts-hematite mineralization stage; (II) barren quartz-fluorite stage; and (III) barren calcite stage. Stage I ore minerals comprise pyrite, chalcopyrite, sphalerite, galena and Pb-Ag-Bi-Sb sulfosalts. Mineralogies of the two mines are different, and arsenopyrite, pyrrhotite, tetrahedrite and iron-rich (up to 21 mole % FeS) sphalerite are restricted to the Oksan mine. A K-Ar radiometric dating for sericite indicates that the Pb-Zn-Cu deposits of the Euiseong area were formed during late Cretaceous age ($62.3{\pm}2.8Ma$), likely associated with a subvolcanic activity related to the volcanic complex in the nearby Geumseongsan Caldera and the ubiquitous felsite dykes. Stage I mineralization occurred at temperatures between > $380^{\circ}C$ and $240^{\circ}C$ from fluids with salinities between 6.3 and 0.7 equiv. wt. % NaCl. The chalcopyrite deposition occurred mostly at higher temperatures of > $300^{\circ}C$. Fluid inclusion data indicate that the Pb-Zn-Cu ore mineralization resulted from a complex history of boiling, cooling and dilution of ore fluids. The mineralization at Jeonheung resulted mainly from cooling and dilution by an influx of cooler meteoric waters, whereas the mineralization at Oksan was largely due to fluid boiling. Evidence of fluid boiling suggests that pressures decreased from about 210 bars to 80 bars. This corresponds to a depth of about 900 m in a hydrothermal system that changed from lithostatic (closed) toward hydrostatic (open) conditions. Sulfur isotope compositions of sulfide minerals (${\delta}^{34}S=2.9{\sim}9.6$ per mil) indicate that the ${\delta}^{34}S_{{\Sigma}S}$ value of ore fluids was ${\approx}8.6$ per mil. This ${\delta}^{34}S_{{\Sigma}S}$ value is likely consistent with an igneous sulfur mixed with sulfates (?) in surrounding sedimentary rocks. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ variation of stage I ore fluids differed between the two mines as follows: the $fs_2$ of ore fluids at Jeonheung changed with decreasing temperature constantly near the pyrite-hematite-magnetite sulfidation curve, whereas those at Oksan changed from the pyrite-pyrrhotite sulfidation state towards the pyrite-hematite-magnetite state. The shift in minerals precipitated during stage I also reflects a concomitant $fo_2$ increase, probably due to mixing of ore fluids with cooler, more oxidizing meteoric waters. Thermodynamic consideration of copper solubility suggests that the ore-forming fluids cooled through boiling at Oksan and mixing with less-evolved meteoric waters at Jeonheung, and that this cooling was the main cause of copper deposition through destabilization of copper chloride complexes.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1565-1576
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• 2023

An atmospheric correction algorithm based on the radiative transfer model is required to obtain remote-sensing reflectance (R_rs) from the Geostationary Ocean Color Imager-II (GOCI-II) observed at the top-of-atmosphere. This R_rs derived from the atmospheric correction is utilized to estimate various marine environmental parameters such as chlorophyll-a concentration, total suspended materials concentration, and absorption of dissolved organic matter. Therefore, an atmospheric correction is a fundamental algorithm as it significantly impacts the reliability of all other color products. However, in clear waters, for example, atmospheric path radiance exceeds more than ten times higher than the water-leaving radiance in the blue wavelengths. This implies atmospheric correction is a highly error-sensitive process with a 1% error in estimating atmospheric radiance in the atmospheric correction process can cause more than 10% errors. Therefore, the quality assessment of R_rs after the atmospheric correction is essential for ensuring reliable ocean environment analysis using ocean color satellite data. In this study, a Quality Assurance (QA) algorithm based on in-situ R_rs data, which has been archived into a database using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Bio-optical Archive and Storage System (SeaBASS), was applied and modified to consider the different spectral characteristics of GOCI-II. This method is officially employed in the National Oceanic and Atmospheric Administration (NOAA)'s ocean color satellite data processing system. It provides quality analysis scores for R_rs ranging from 0 to 1 and classifies the water types into 23 categories. When the QA algorithm is applied to the initial phase of GOCI-II data with less calibration, it shows the highest frequency at a relatively low score of 0.625. However, when the algorithm is applied to the improved GOCI-II atmospheric correction results with updated calibrations, it shows the highest frequency at a higher score of 0.875 compared to the previous results. The water types analysis using the QA algorithm indicated that parts of the East Sea, South Sea, and the Northwest Pacific Ocean are primarily characterized as relatively clear case-I waters, while the coastal areas of the Yellow Sea and the East China Sea are mainly classified as highly turbid case-II waters. We expect that the QA algorithm will support GOCI-II users in terms of not only statistically identifying R_rs resulted with significant errors but also more reliable calibration with quality assured data. The algorithm will be included in the level-2 flag data provided with GOCI-II atmospheric correction.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.221-227
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• 2012

In Korea, ocean dumping has been widely used as the ultimate disposal of sewage sludge. However, ocean dumping of food wasted and sewage sludge from 2013 is expected to legally restricted as London convention on marine pollution prevention has been effective in 2009. This research aims to examine the effect of HEAS in treating the environmental pollution load caused by organic high concentrated sludge. Thus, onsite laboratory scale treatability test using HEAS was adopted to treat the high concentrated organic sludge from sewage and industrial wastewater treatment plant. The research results showed that the HEAS is useful to reduce the environmental pollution caused by organic high concentrated sludge. Specific results are as follows. 1. The organic removal after the sludge digestion using the high efficiency aeration system was 55.2-85.8%. Although these results were lower than those from the general sewage treatment, the high efficiency aeration system could be evaluated as efficient, considering the object sludge contained the industrial waster water. 2. The average removal efficiency was about 25.2%. 3. It was revealed that sludge digestion by the high efficiency aeration system could effectively contribute to the sludge treatment cost. Especially, the high efficiency aeration system is more applicable to the onsite treatment of small sewage and wastewater treatment plant that contains high solid content sludge, industrial wastewater sludge, high fixed solid sludge.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.74-81
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• 2007

In this paper, CMOS analog-to-digital converter (ADC) with a 6-bit 1GSPS at 1.8V is described. The architecture of the proposed ADC is based on a folding type ADC using resistive interpolation technique for low power consumption. To reduce the power consumption, a folder reduction technique to decrease the number of folding blocks (NFB) by half of the conventional ones is proposed. further, a novel layout technique is introduced for compact area. With the clock speed of 1GSPS, the ADC achieves an effective resolution bandwidth (ERBW) of 500MHz, while consuming only 60mW of power. The measured INL and DNL were within $\pm$0.5 LSB, $\pm$0.7 LSB, respectively. The measured SNR was 34.1dB, when the Fin=100MHz at Fs=300MHz. The active chip occupies an area of 0.27$mm^2$ in 0.18um CMOS technology.