• Tribology and Lubricants
• /
• v.35 no.6
• /
• pp.382-388
• /
• 2019

It is currently well known that surface textures act as lubricant reservoirs, entrap wear debris, and hydrodynamic bearings, which can lead to certain increases in load-carrying capacities. Until recently, the vast majority of research has focused on parallel sliding machine components such as thrust bearings, mechanical face seals, piston rings, etc. However, most sliding bearings have a convergent film shape in the sliding direction and their hydrodynamic pressure is mainly generated by the wedge action. Following the first part of the present study that investigates the effect of groove position on the lubrication performances of inclined slider bearings, this paper focuses on the effects of groove depths and film thicknesses. Using a commercial computational fluid dynamics (CFD) code, FLUENT, the continuity and Navier-Stokes equations are numerically analyzed. The results show that the film thickness and groove depth have a significant influence on the pressure distribution. The maximum pressure occurs at the groove depth where the vortex is found and, as the depth increases, the pressure decreases. There is also a groove depth to maximize the supporting load with the film thickness. The friction force acting on the slider decreases with deeper grooves. Therefore, properly designed groove depths, depending on the operating conditions, can improve the load-carrying capacity of inclined slider bearings as compared to the bearings without a groove.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.66-72
• /
• 2020

In order to cultivate talented people with national economic influence in the rapidly changing 21st- century modern society, STEM(Science Technology Engineering Mathematics) education has been emphasized in advanced countries such as America and England. In South Korea, STEAM(Science Technology Engineering Arts Mathematics) education is emphasized by adding Arts. The objective of STEAM education is to strengthen the interest and motivation of learners, to focus on experience, exploration, experimentation, to solve convergent thinking and real-life problems, rather than cramming method of teaching and memorization. This study identifiesan instructional design for converged English, the world's official language, and science which is found in nearly all disciplines. With the development of the 4th industrial revolution based on the PBL model, learners participate in their lessons voluntarily for problem-solving skills. The instructional design based on the ADDIE model consists of 5 procedures: Analysis, Design, Development, Implementation, and Evaluation. The goal of fostering talented people with national economic influence is also important, and the teacher in education must recognize the importance of STEAM education and an appropriate instructional design should be studied constantly.

• The Journal of the Korea Contents Association
• /
• v.13 no.3
• /
• pp.318-329
• /
• 2013

Spatial information has influenced government policy formation, business strategy implementation, and our everyday life enormously. Digital earth enterprises providing global spatial data services emerge as spatial data industry grows rapidly. So it is highly desirable to grasp recent trends in the industry and find critical success factors (CSFs) for the digital earth firms. The purpose of this study is to compare strategies of digital earth enterprises and find CSFs for them. In addition, strategy analysis framework elaborations, systematic analysis of spatial data industry and market segmentation based on value chain are also performed to trace and cope with the volatile industry environment. Derived CSFs are as follows. First, acquisition of differentiated high quality spatial data is needed. Second, customer oriented convergent contents should be developed. Third, advanced platform functionalities must be provided to consumers. Finally, construction of efficient and effective global value chain is desirable.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.9
• /
• pp.1554-1562
• /
• 2018

The type I interferons (IFNs) play a vital role in activation of innate immunity in response to viral infection. Accordingly, viruses have evolved to employ various survival strategies to evade innate immune responses induced by type I IFNs. For example, hepatitis E virus (HEV) encoded papain-like cysteine protease (PCP) has been shown to inhibit IFN activation signaling by suppressing K63-linked de-ubiquitination of retinoic acid-inducible gene I (RIG-I) and TANK-binding kinase 1 (TBK1), thus effectively inhibiting down-stream activation of IFN signaling. In the present study, we demonstrated that HEV inhibits polyinosinic-polycytidylic acid (poly(I:C))-induced $IFN-{\beta}$ transcriptional induction. Moreover, by using reporter assay with individual HEV-encoded gene, we showed that HEV methyltransferase (MeT), a non-structural protein, significantly decreases RIG-I-induced $IFN-{\beta}$ induction and $NF-{\kappa}B$ signaling activities in a dose-dependent manner. Taken together, we report here that MeT, along with PCP, is responsible for the inhibition of RIG-I-induced activation of type I IFNs, expanding the list of HEV-encoded antagonists of the host innate immunity.

• Environmental Engineering Research
• /
• v.21 no.4
• /
• pp.373-383
• /
• 2016

Cheonsu Bay, one of the most important in Korea as a coastal fishery is a semi-enclosed bay that is surrounded by large farmlands and industrial areas. This coastal environment has been affected by anthropogenic pollutants, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). The objectives of this study were to investigate the distribution of PCBs and OCPs in sediment, Manila clams, and mussels from Cheonsu Bay; the accumulation pattern of these chemicals in these bivalves in relation to seasonal changes; and the ecological risk from sediments and the risk to the Korean population from the consumption of these bivalves. The levels of ${\Sigma}PCBs$, ${\Sigma}DDT$, and ${\Sigma}HCHs$ were 69.3-109, 40.3-49.3 and 6.25-17.8 ng/g lipid in Manila clams, and 70.6-159, 38.6-102 and 9.00-13.5 ng/g lipid in Mussels. Significant seasonal variations in PCBs and OCPs concentrations were observed in the two bivalves, suggesting that the accumulation of PCBs and OCPs in these species is related to their spawning times. The dietary intake of these two bivalves and the resulting lifetime cancer risk (LCR) and non-cancer risk were calculated for the human population. The consumption of these bivalves seemed to be safe in relation to human health with negligible LCR and non-cancer risk.

• The Journal of the Korea Contents Association
• /
• v.17 no.8
• /
• pp.366-381
• /
• 2017

This study was conducted in order to evaluate validity and reliability of the Korean version scale to measure maternal satisfaction in normal birth(KSMMS-normal birth). The SMMS-normal birth was administered to 205 postnatal women, together with the perception of birth experience scale. An exploratory factor analysis revealed six factors solution for the twenty three-item scale. Confirmatory factor analysis supported good convergent and discriminant validities, and factor correlations ranged from 0.11 to 0.57. The KSMMS-normal birth showed good concurrent validity with the perception of birth experience scale. The Cronbach alpha for the total scale was .91. It ranged between .80 to .90 for six subscales. The KSMMS-normal birth is reliable and valid instrument to measure maternal satisfaction. Therefore this scale can be used to assess maternal satisfaction in normal birth at hospital during the postpartum 2nd and 3rd day.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.4
• /
• pp.67-74
• /
• 1999

Problems created by supersonic jet impinging on solid objects or ground arise in a variety of situations. For example multi-stage rocket separation, deep-space docking, V/STOL aircraft, jet-engine exhaust, gas-turbine blade, terrestrial rocket launch, and so on. These impinging jet flows generally contain a complex structures. (mixed subsonic and supersonic regions, interacting shocks and expansion waves, regions of turbulent shear layer) This paper describes experimental works on the phenomena (surface pressure distribution, flow visualization) when underexpanded supersonic jets impinge on the perpendicular, inclined plate using a supersonic cold-(low system. The used supersonic nozzle is convergent-divergent type, exit Mach number 2, The maximum on the plate when it was inclined was much larger than perpendicular plate, owing to high pressure recoveries through multiple shocks. Surface pressure distribution as to underexpanded ratio showed similar patterns together.

• Proceedings of the KSRS Conference
• /
• v.2
• /
• pp.752-755
• /
• 2006

Evaportranspiration is an important factor in hydrology cycle. Traditionally, it is measured by using basin or empirical formula with meteorology data, while it does not represent the evaportranspiration over a regional area. With the advent of improved remote sensing technology, it becomes a surface parameter of research interest in the field of remote sensing. Airborne and satellite imagery are utilized in this study. The high resolution airborne images include visible, near infrared, and thermal infrared bands and the satellite images are acquired by MODIS. Surface heat fluxes such as latent heat flux and sensible heat flux are estimate by using airborne and satellite images with surface meteorological measurements. We develop a new method to estimate the evaportranspiration over the rice paddy. The surface heat fluxes are initialized with a surface energy balance concept and iterated for convergent solution with atmospheric correct functions associated with aerodynamic resistance of heat transport. Furthermore, we redistribute the total net energy into sensible heat and latent heat fluxes. The result reveals that radiation and evaporation controlled extremes can be properly decided with both airborne and satellite images. The correlation coefficient of latent heat flux and sensible heat flux with corresponding in situ observations are 0.66 and 0.76, respectively. The relative root mean squared errors (RMSEs) for latent heat flux and sensible heat flux are 97.81 $(W/m^2)$ and 124.33 $(W/m^2)$, respectively. It is also shown that the newly developed retrieval scheme performs well when it is tested by using MODIS date.

• Journal of Convergence for Information Technology
• /
• v.8 no.5
• /
• pp.37-43
• /
• 2018

The study was implemented the convergence research on oral health beliefs G area S university convergence course. The final analysis of 168 students agreed to research purpose and method was conducted from March 26 to June 11, 2018. The benefits was highest at 3.99 points, and the severity was lowest at 2.01 about oral health belief. The t-test and ANOVA outcome about oral health improvement behavior and oral health belief were dental clinic visit was benefits and importance, scaling experience was sensitivity, benefits and importance, use of auxiliary oral care products was importance to be statistically significant. The imported oral health beliefs for oral health improve and a variety of programs for oral health education need to be developed within university to learn knowledge of oral health behavior and attitude changed for correct oral health beliefs.

• The International Journal of Costume Culture
• /
• v.4 no.3
• /
• pp.217-228
• /
• 2001

This study* 1) historically considered the meaning of light which has frequently wed as the subject of artistic expression since Renaissance, in order to grasp an artistic atmosphere about light and rays before the allusion of Rayonism. non it inspected closely the course of changes of light as a result of historic circumstances and intended to understand how Rusian Rayonism of the 20th, which maintained these effects of light more rationally, had an influence on modern fashion. It was created by Mikhail Larionov and developed by his wife, N. Goncharova. The main special feature of Rayonism wag the crossing of reflected ras, emerging from various objects. Most of these things depended on line and color. Re purpose of Rayonism paintings was to create a new space from arising from which reflected rays from various selected objected crossed one another. Namely, artists maintained that they should give up various objects of visible world and express rays which were reflected objects and crossed in complex. Rayonists were affected by Cubism and Futurism and came to fake an interest in relations whose rays of parallel or convergent color made, also in expression of themes. Since that, Rayonsim affected Supermatisme and Constructivism. Re pursuit of light and rays from the 19th until the early 20th came to appear in fashion as well as in art as it was. As Rayonists created a new space from which reflected rays from selected objects crossed one another, they used line and color as the main techniques of expression. in this way the attempt which intended to express rays, using itself of the line and color, appeared as futile design of tots of designs like Donna Karan, Cianni Versace and Rococo Barocco and so on of Modem fashion. This was designed for essential elements of pure art to express the new aestheic consciousness through fashion.