• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.52.2-52.2
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• 2013

We explore the relative importance of the role of small-scale environment and large-scale environment in triggering nuclear activity of the local galaxies using a volume-limited sample with $M_r$ < -19.5 and 0.02 < z < 0.0685 selected from the Sloan Digital Sky Survey Data Release 7. The active galactic nuclei (AGN) host sample is composed of Type II AGNs identified with flux ratios of narrow emission lines with S/N > 6 and the central velocity dispersion of the sample galaxies is limited to have a narrow range between 130 < ${\sigma}$ < 200($km\;s^{-1}$), corresponding to 7.4 < $log(M_{BH}/M_{\odot})$ < 8.1 in order to fix the mass of the supermassive black hole at the center of its host galaxy. In this study, we find that the AGN fraction ($f_{AGN}$) of late-type galaxies are larger than of early-type galaxies and that for target galaxy with late-type nearest neighbor, $f_{AGN}$ starts to increase as the target galaxy approaches the virial radius of the nearest neighbor (about a few hundred kpc scale). The latter result may support the idea that the hydrodynamic interaction with the nearest neighbor as well as tidal interaction and merger also plays an important role in triggering the nuclear activity of galaxy. We also find that early-type cluster galaxies show decline of AGN activity compared to ones in lower density regions, whereas the direction of dependence of AGN activity for late-type galaxies is opposite.

• Economic and Environmental Geology
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• v.27 no.3
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• pp.219-229
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• 1994

The Sangra Pb-Zn deposit is located in the Gampo area. Most Cretaceous sedimentary rocks and Paleogene felsic intrusives in the study area have experienced intense propylitization. Such propylitization and Pb-Zn mineralization in ore veins are involved with the fluid having very low oxygen isotopic composition.Sulfurisotopic equilibrium temperature during the main Pb-Zn mineralization (late stage I) is calculated as $T=275^{\circ}{\sim}295^{\circ}C$. Oxygen and sulfur fugacity in late stage I fluid is estimated as $logfO_2=-34.4{\sim}-29.1$ and $logfS_2=-12.0{\sim}-8.2$ bars. It is inferred that the sulfur isotopic composition oflate stage I fluid was very high such as ${\delta}^{34}S_{{\Sigma}S}=+22.4{\sim}+22.5$‰ and the origin of sulfur was ocean water sulfate. Oxygen and hydrogen isotopic composition of water in ore-forming fluid was gradually increased and more abundantly affected by ocean water from early to late mineralization stage as follows; (late stage I) ${\delta}^{18}O_{H2O}=-7.2{\sim}-1.1$‰, ${\delta}D_{H2O}=-87{\sim}-84$‰, (stage II) ${\delta}^{18}O_{H2O}=-2.4{\sim}-0.8$‰, ${\delta}D_{H2O}=-39{\sim}-21$‰ (stage III) ${\delta}^{18}O_{H2O}=+0.7{\sim}+12.6$‰, ${\delta}D_{H_2O}=-49{\sim}-42$‰. The pH in ore-forming fluid was about 4.7 during late stage I and is thought to have been gradually decreased from late stage I to stage II mineralization.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2145-2150
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• 2016

Background: Infection with hepatitis B virus (HBV) is a major global public health problem, with a wide spectrum of clinical manifestations. Human cytosolic glutathione-S-transferases (GSTs) include several classes such as alpha (A), mu (M), pi (P), sigma (S), zeta (Z), omega (O) and theta (T). The present study aimed to investigate the role of GST omega genes (GSTO1 and GSTO2) in different groups of patients infected with HBV. Materials and Methods: HBV groups were classified according to clinical history, serological tests and histological analysis into normal carriers (N), acute (A), chronic (CH), cirrhosis (CI) and hepatocellular carcinoma (HCC) cases. The study focused on determination of the genotypes of GST omega genes (GSTO1 and GSTO2) and GST activity and liver function tests. Results: The results showed that GSTO1 (A/A) was decreased in N, A, CH, CI and HCC groups compared to the C-group, while, GSTO1 (C/A) and GSTO1(C/C) genotypes were increased significantly in N, A, CH, CI and HCC groups. GSTO2 (A/A) was decreased in all studied groups as compared to the C-group but GSTO2(A/G) and GSTO2(G/G) genotypes were increased significantly. In addition, GST activities, albumin and TP levels were decreased in all studied groups compared to the C-group, while the activities of transaminases were increased to differing degrees. Conclusions: The results indicate that GSTO genetic polymorphisms may be considered as biomarkers for determining and predicting the progression of HBV infection.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1232-1237
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• 2009

The ICAO and FAA are developing and verifying of GBAS for civil aircraft landing and take-off. The guarantee of aircraft integrity issue is the important part of GBAS. To guarantee integrity, the GBAS ground facility broadcasts various informations to aircraft. The informations are related to the estimated accuracy of each pseudorange correction and the estimated error terms, for example B-value and standard deviation of the ground facility error. These parameters are used to calculate position error (estimated value of the user). If estimated position errors don't satisfy requirements, aircraft use alternate navigation means. In this paper, GBAS reference stations's real data, which operated by KARI (Korea Aerospace Research Institute) in Jeju international airport, are used to development of new ground facility error standard deviation model. We verify improvement of GBAS availability, with respected to vertical protection level, using B-value based a new ground facility error standard deviation model and a sigma inflation factor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.556-565
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• 2018

The age and growth of butter clams Saxidomus purpuratus were estimated using transmitted light on the shells of 364 samples from January 2017 to December 2017 in Jinhae Bay. Based on monthly variation in the marginal index (MI) of the shell, it is assumed that rings are formed once a year during the period from July to August in this species. The relationship between shell length (SL; mm) and shell height (SH; mm) was expressed by the equation SH=0.8053SL-2.9636 ($R^2=0.94$) and between SL and shell width (SW; mm) by the equation SW=0.5648SL-3.7105 ($R^2=0.90$). The relationship between SL and total weight (TW; g) was expressed by the following equation: $TW=0.00009SL^{3.2141}$ ($R^2=0.96$). von Bertalanffy's growth parameters were estimated using the regression wizard in the SigmaPlot computer program (Systat Software, Inc., v. 10.0). The maximum shell length ($SL_{\infty}$) was 126.16 mm, growth rate was 0.2030/year, theoretical age at shell length 0 ($t_0$) was -0.52 years, and asymptotic total weight ($TW_{\infty}$) was 509.17 g. Growth curves for SL and TW fitted to the von Bertalanffy's equation were expressed as follows: $SL_t=126.16(1-e^{-0.2030(t+0.52)})$, $TW_t=509.17(1-e^{-0.2030(t+0.52)})^{3.2141}$.

• Journal of Welding and Joining
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• v.32 no.2
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• pp.48-53
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• 2014

This study was carried out to investigate the effect of postweld heat treatment(PWHT, 930, 1080, $1230^{\circ}C$) on the microstructure, phase formation, pitting corrosion and mechanical properties such as hardness, tensile strength and impact values of super duplex stainless steel(UNS S32750) multipass welds. Based on the microstructural examination and X-ray diffraction analysis, it was found that the ${\sigma}$ phase was formed in the welds heat treated at $930^{\circ}C$ in which the ferrite content greatly decreased into 5~10% in the welds. The secondary austenite was formed in the reheated zone of welds and redissolved into ferrite with increasing heat treatment temperatures. The tensile strength and impact values of welds heat treated at $930^{\circ}C$ were the lowest and revealed the brittle fracture surface. The weight loss by pitting corrosion increased with test temperatures. It was confirmed that pitting corrosion occurred mainly in secondary austenite of reheated zones. The postweld heat treatment temperature is recommended to be in the range of $1050{\sim}1150^{\circ}C$.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.113-127
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• 2015

An interface in smart device environment is changing to TUI(touch user interface) environment where a system is being controlled by physical touch, differently from a system controlled through conventional mouse and keyboard. What is more important than anything else in this TUI environment is to implement interface in consideration of learn ability and cognitive constructivism according to user's experience. Therefore, now is the time when it is necessary to carry out various studies on smart content design process going a step farther together with discussing the details of user's experience factor. Hence, this study was intended to look into what effect a user's experiential traits had on the production of contents for the purpose of measures for improving TUI user satisfaction in order to effectively realize contents in smart environment. Results were yielded by using a statistical empirical analysis such as cross-tabulation analysis according to important variable and user, paired t-test, multiple response analysis, and preference frequency analysis of user preference on the basis of a survey. As a result, a system was presented for implementing DFSS(Design For Six Sigma) process. TUI experience factor can be divided into direct habitual experience, direct learning experience, indirect habitual experience, and indirect learning experience. And in the results of study, it was possible to find that the important variables of this study had a positive effect on the improvement of use satisfaction with contents on the whole according to the user convenience of smart contents. This study is expected to have a positive effect on efficient smart device-based contents production by providing objective information according to empirical analysis to smart media-based developer and designer and presenting a model for improving the changed TUI usability.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.605-621
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• 1993

The gingival hyperplasia refers to an increase in the size of the gingival tissue produced by an increase in the number of its component cells. In order to investigate the cellular change in epithelium and subepithelial tissue of noninflammatory gingival hyperplasia, the gingival tissues were surgically obtained from the patients with dilantin gingival hyperplasia and idiopathic gingival hyperplasia. The excised tissue samples were fixed in neutral formalin for 6-24 hours, embedded with paraffin, sectioned at $4-6{\mu}m$ in thickness, mounted on glass slides coated with 3-aminopropyltriethoxysilane(Sigma Chemical Co., St. Louis, MO, U.S.A.) and immunocytochemically processed by Avidin-Biotin peroxidase complex method for detecting proliferating cell nuclear antigen, tenascin and collagen type IV. Monoclonal mouse anti-human PCNA antibody(Oncogene Science, Uniondale, NY, U.S.A., 1 : 250,000), monoclonal mouse anti-human tenascin antibody(Chemicon-International Inc., Temecula, CA, U.S.A., 1:5,000), and monoclonal mouse anti-human collagen type IV(Dakopatts, Glostrup, Denmark, 1: 50) were used as primary antibodies. The results were as follows: 1. In non-inflammatory gingival hyperplasia, the positive reaction to proliferating cell nuclear antigen was localized in the basal cell layer of gingival epithelium and well-developed rete pegs. 2. The positive reaction to tenascin was shown in the connective tissue subjacent to basament membrane of gingival tissue, and especially strong positive reaction was noted in the tip portion of connective tissue projections. 3. The positive reaction to collagen type IV was localized along the basement membranes of gingival epithelium and blood vessels. The results suggest that connective tissue enlargement may affect the proliferation of gingival epithelium.

• Journal of the Korean institute of surface engineering
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• v.54 no.3
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• pp.102-111
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• 2021

The corrosion behaviors of laser-welded super duplex stainless steel tubes with post-weld heat treatment(PWHT) conditions(950, 1000, 1050, 1100 ℃ for 5 and 30 min) were evaluated by electrochemical potentiodynamic polarization and critical pitting temperature measurements. This study showed that the critical metallurgical factors affecting the degradation of corrosion resistance of a steel tube in as-welded condition were the unbalanced phase fraction(ferrite:austenite = 94:4), Cr₂N precipitation, and phase transformation from the austenite phase to ɛ-martensite(via stress-induced phase transformation). The improvement in the corrosion resistance of the welded specimen depends greatly on the PWHT conditions. The specimens after PWHT conducted below 1000 ℃ showed inferior corrosion resistance, caused by precipitation of the sigma phase enriched with Cr and Mo. At 1100 ℃ for a longer duration in PWHT, the ferrite phase grows, and its fraction increases, leading to an unbalanced phase fraction in the microstructure. As a result, pitting can be initiated primarily at the interface between the ferrite/austenite phase, particularly in base metal.

• Structural Engineering and Mechanics
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• v.84 no.5
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• pp.685-697
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• 2022

Nanotechnology has become one of the interesting technique used in material science and engineering. However, it is low used in civil engineering structures. The purpose of the present study is to investigate the static behavior of concrete plates reinforced with silica-nanoparticles. Due to agglomeration effect of silica-nanoparticles in concrete, Voigt's model is used for obtaining the equivalent nano-composite properties. Furthermore, the plate is simulated mathematically with higher order shear deformation theory. For a large use of this study, the concrete plate is assumed resting on a Pasternak elastic foundation, including a shear layer, and Winkler spring interconnected with a Kerr foundation. Using the principle of virtual work, the equilibrium equations are derived and by the mean of Hamilton's principle the energy equations are obtained. Finally, based on Navier's technique, closed-form solutions of simply supported plates have been obtained. Numerical results are presented considering the effect of different parameters such as volume percent of SiO₂ nanoparticles, mechanical loads, geometrical parameters, soil medium, on the static behavior of the plate. The most findings of this work indicate that the use of an optimum amount of SiO₂ nanoparticles on concretes increases better mechanical behavior. In addition, the elastic foundation has a significant impact on the bending of concrete slabs.