• Journal of the Korean Society of Visualization
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• v.20 no.1
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• pp.38-44
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• 2022

An interscale transport of the turbulent kinetic energy (TKE) and Reynolds shear stress (RSS) is examined in an adverse pressure gradient (APG) turbulent boundary layer (TBL). The direct numerical simulation data of an APG TBL at Re_τ = 834 and β = 1.45 is employed. The TKE and RSS transport equations are divided into large and small scales, leading to the introduction of interscale transport. The TKE mainly transfers from large scales to small ones in the outer region, and vice versa for the RSS. An interscale transport of TKE and inverse interscale transport of RSS are amplified by APG, and the latter results in the increase in large scales of TKE production. Some of outer large scales of enhanced TKE transfer to small scales and then dissipate by viscosity, and the remains dissipate turbulent-non-turbulent interfaces by turbulent transport.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.113-119
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• 1986

A characteristic mineralogical zonal distribuion is observed in a large scale(whole ore- body) small scales(handy specimens). They show similar chemical variations: most of elements except CaO were supplied by hydrothermal fluids to form skarns. Garnets occuring in the pyroxene-garnet skarn have a wide range of chemical composition ranging from andradite to grossularite, while individual grains of the garnets also show a similar zonation of chemical composition varied between grossularite and andradite. Highly contained Mo-bearing scheelites are generally concentrated in the central part of the Sang- dong skarn orebody. Similarly, some large grains of scheelite show a nice zonation due to different contents of Mo, highly enriched in the core of the scheelite crystal. This geochemical similarity in the large scale and small scales suggests the Sangdong skarn formation was achieved under a certain chemical environment, and detailed studies on a small scale texture could be a clue to understand a whole ore deposit.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.75.2-75.2
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• 2012

Turbulence is ubiquitous in astrophysical fluids such as the interstellar medium and intracluster medium. To maintain turbulent motion, energy must be injected into the fluids. In turbulence studies, it is customary to assume that the fluid is driven on a scale, but there can be many different driving mechanisms that act on different scales in astrophysical fluids. We expect different statistical properties of turbulence between turbulence with single driving scale and turbulence with double driving scales. In this work, we perform 3-dimensional incompressible MHD turbulence simulations with energy injection in two ranges, 2${\surd}$12 (large scale) and 15

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.37-37
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• 2019

Cryopreservation is one of the ideal and suitable methods for long-term storage of plant germplasm. The plant contaminated with diseases and pathogens are decreased the multiplication rate, survival rate and high quality of plants after cryopreservation. The aim of this work was to improve a micropropagation method for lily in Korea, which are cultivars and indigenous plant. In the last process of rinsing scales after surface-sterilization, we tried to control the diseases and pathogens lived within the tissue by rinsing in 0.03% sodium hypochlorite (NaClO) instead of sterile distilled water. Bulb scales of Lilium were cultured in vitro on MS medium supplemented with Plant Preservative Mixture (PPM). The newly small bulb formed from bulb-scales was transferred to MS medium. We checked the non-contamination and survival rate after 2 weeks in culture. Non-contamination was shown to be 70 to 90% in formed small bulbs. This study will help to mitigate microbial contamination in Lilium species micropropagation for cryopreservation.

• Journal of the Korean Society of Combustion
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• v.14 no.3
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• pp.29-36
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• 2009

Simulation is performed to analyze the characteristics of turbulent spray combustion in a diesel engine condition. An extended Conditional Moment Closure (CMC) model is employed to resolve coupling between chemistry and turbulence. Relevant time and length scales and dimensionless numbers are estimated at the tip and the mid spray region during spray development and combustion. The liquid volume fractions are small enough to support validity of droplets assumed as point sources in two-phase flow. The mean scalar dissipation rates (SDR) are lower than the extinction limit to show flame stability throughout the combustion period. The Kolmogorov scales remain relatively constant, while the integral scales increase with decay of turbulence. The chemical time scale decreases abruptly to a small value as ignition occurs with subsequent heat release. The Da and Ka show opposite trends due to variation in the chemical time scale. More work is in progress to identify the spray combustion regimes.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.35.3-36
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• 2016

Density and velocity perturbations in scales most relevant for the first galaxy formation are strongly affected by large-scale density perturbations, velocity-divergence perturbations and the baryon-cold dark matter (CDM) streaming velocities. Even at redshifts as high as z~200, this mode-mode coupling imprints a significant impact on the small-scale perturbations, at the wavenumber k >${\sim}100Mpc^{-1}$, as was calculated in our recent work. This implies that cosmological initial conditions based on the usual linear theory is no longer valid in these scales. We present a new cosmological initial condition generator, BCCOMICS, which generates initial conditions for the cold dark matter (CDM) and baryons in scales most relevant for the first galaxy formation. BCCOMICS is based on the linear perturbation theory including the mode-mode coupling terms, and generates cosmological initial conditions for the SPH-basded code GADGET and the AMR-based code ENZO. We also present our preliminary result on the cosmic variance of the first galaxy formation, studied by using BCCOMICS.

• Korean Journal of Materials Research
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• v.12 no.11
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• pp.845-849
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• 2002

Alloys of $Fe_3$Al, $Fe_3$Al-6Cr, $Fe_3$Al-4Cr-1Mo, $Ni_3$Al, and $Ni_3$Al-2.8Cr were oxidized at $1000^{\circ}C$ in air, and the oxide scales formed were studied using XRD. SEM, EPMA, and TEM. The oxide scales that formed on $Fe_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$ containing a small amount of dissolved Fe and Cr ions, whereas those that formed on $Ni_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$, together with a small amount of $NiAl_2$$O_4$, NiO and dissolved Cr ions. For the entire alloys tested, nonadherent oxide scales formed, and voids were inevitably existed at the scale-matrix interface.

• Journal of the Korean Data and Information Science Society
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• v.22 no.2
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• pp.227-234
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• 2011

In this study, we propose order selection methods based on scaled lift. This study is proposed to overcome the problem that the lift used by Park and Kim (2010) takes unbounded values and thus it is hard to know how big (or small) lift value is big (or small). The first scaled lift just scales lift, so that it takes values between 0 and 1, and the second scaled lift scales lift-1, so that it takes values between -1 and 1. In other words, the first method scales lift only and the second methods ceters and scales lift. We apply order selection methods based on scaled lift to acute appendicitis patients in emergency room and compare them with the results based on lift.

• Safety and Health at Work
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• v.12 no.2
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• pp.192-200
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• 2021

Background: A number of accidents have occurred in small and medium enterprises (SMEs). Efforts in reducing accidents have been undertaken through the implementation of safety behaviors. Unfortunately, few studies have examined motives behind unsafe behaviors, such as safety silence motives. This study aimed to observe the motives underlying safety behaviors, namely safety silence motive (SSM) (SSM-relation, SSM-climate, SSM-issue, and SSM-job) and to evaluate the effect of SSM and safety communication on safety participation in different industrial sectors and scales. Materials and Methods: Eighty workers from two industrial sectors and scales of SMEs were involved. They were instructed to fill out a set of questionnaires. A five-Likert scale was used to respond. An independent t test was applied to find any significant differences. The partial least square-structural equation modeling for multigroup was used to develop a model on relations among the variables. Results: The results showed that SSM scores were high in SMEs, and the scores were different across industrial sectors and scales. SSM had a negative influence on safety communication, and safety communication positively influenced safety participation. Conclusion: The study of SSM, safety communication, and safety participation in different sectors and scales should be separated in SMEs.

• Journal of Species Research
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• v.9 no.3
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• pp.273-279
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• 2020

We describe a newly recorded brittle star to South Korea, Amphiura (Amphiura) digitula (H.L. Clark, 1911), that was collected from Geoje Island, at a depth of 47 m. The species is characterized by a small disk, covered by numerous fine scales, small radial shields that are wider than long, a small stumpy hook at the distal end of the radial shield, two tooth papilla, two adoral shield spines, 2nd adoral shield spine longer than other, tapered dramatically toward dull tip, five arms with four proximal arm spines, and two tentacle scales. We also obtained a 657 bp sequence from COI gene and the amplified sequence matched the general DNA barcoding region. The NJ and ML phylogenetic analyses revealed A. (A.) digitula as monophyletic in the Amphiura clade. This species is clearly distinguished from other Amphiura species by morphological characteristics and the mitochondrial COI sequence, and thus represents the sixth Amphiura species reported to occur in Korea.