• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.3
• /
• pp.180-183
• /
• 2001

This study was conducted to find out the effect of ripened grain and rice quality by the breeding of rice dust mite (Steneotarsonemus spinki). Growth temperature of sample (Suwon 441 and Ilpumbyeo) was maintained from 22$^{\circ}C$ (during night) to 26$^{\circ}C$ (during day) in a controlled phytotron. Plant hight and number of panicle could not showed the difference by the discoloration degree of leaf sheath. But number of spikelet was reduced affected by discoloration degree of leaf sheath. Ratio discoloration of grain was increased according to circumstances more discoloration degree of leaf sheath in Suwon 441 then Ilpumbyeo. The perfect rice grain was observed to similar Suwon 441 and Ilpumbyeo in the IV degree of ratio discoloration of grain, but less Suwon 441 than Ilpumbyeo in III and II, in such a case comparison between coloration and discoloration.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.6
• /
• pp.3416-3422
• /
• 2014

A shock absorber rod is located in the center of the absorber piston and is responsible for the reciprocating movement portion. If it has surface defects, the damping performance of product will be adversely affected. A rod surface has gloss by heat treatment. Therefore, it is difficult to find a defect, such as dust, imprints, and blowholes. Because a total inspection is achieved by visual inspection by workers, it causes eyestrain and the quality of the product is not constant. In this paper, a machine vision system was developed to find a defect using a line-scan camera. The machine can detect surface defects than 0.3mm. To minimize the occurrence probability of defects on the inspection process, the developed auto inspection system had an automatic feeding system and incorporated a protection system. Through the development of this system, which relies on the operator's visual inspection of the surface of the shock absorber, the Rod inspection system constructed quality inspection standards and standardized tests to ensure improved reliability.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.58.3-59
• /
• 2015

Dynamical expansion of H II regions plays a key role in dispersing surrounding gas and therefore in limiting the efficiency of star formation in molecular clouds. We use analytic methods and numerical simulations to explore expansions of spherical dusty H II regions, taking into account the effects of direct radiation pressure, gas pressure, and total gravity of the gas and stars. Simulations show that the structure of the ionized zone closely follows Draine (2011)'s static equilibrium model in which radiation pressure acting on gas and dust grains balances the gas pressure gradient. Strong radiation pressure creates a central cavity and a compressed shell at the ionized boundary. We analytically solve for the temporal evolution of a thin shell, finding a good agreement with the numerical experiments. We estimate the minimum star formation efficiency required for a cloud of given mass and size to be destroyed by an HII region expansion. We find that typical giant molecular clouds in the Milky Way can be destroyed by the gas-pressure driven expansion of an H II region, requiring an efficiency of less than a few percent. On the other hand, more dense cluster-forming clouds in starburst environments can be destroyed by the radiation pressure driven expansion, with an efficiency of more than ~30 percent that increases with the mean surface density, independent of the total (gas+stars) mass. The time scale of the expansion is always smaller than the dynamical time scale of the cloud, suggesting that H II regions are likely to be a dominant feedback process in protoclusters before supernova explosions occurs.

• Publications of The Korean Astronomical Society
• /
• v.27 no.4
• /
• pp.259-260
• /
• 2012

Polycyclic aromatic hydrocarbons (PAHs) in Galactic planetary nebulae (PNe) are investigated by means of the unidentified infrared (UIR) bands. Continuous near- to mid-infrared spectra of PNe are obtained with the AKARI/IRC and the Spitzer/IRS. All 19 PNe in the present study show prominent dust emissions and we investigate the variation in the intensity ratios among the UIR bands. The ionization fraction and the size distribution of PAHs in PNe are derived using the UIR band ratios. We find that the ionization fraction of PAHs in PNe is around 0.0-0.6 and that small PAHs are scarce. The present result indicates a systematic trend of the $3.4{\mu}m$ aliphatic feature to become weak as the PAH ionization fraction increases.

• Publications of The Korean Astronomical Society
• /
• v.27 no.4
• /
• pp.275-279
• /
• 2012

We investigate the mid-infrared (MIR) to far-infrared (FIR) properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert telescope (BAT) all-sky hard X-ray (14-195 keV) survey, based on the cross correlation with the infrared survey catalogs of AKARI, IRAS and WISE. Out of 135 non-blazar AGNs in the Swift/BAT 9-month catalog, we obtain the MIR photometric data for 128 sources in either the 9, 12, 18, 22, and $25{\mu}m$ band. We find a good correlation between their hard X-ray and MIR luminosities ranging three orders of magnitude (42 < log ${\lambda}L_{\lambda}$(9, $18{\mu}m$) < 45), which is tighter than that with the FIR luminosities at $90{\mu}m$. Both X-ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori models rather than homogeneous ones.

• Particle and aerosol research
• /
• v.8 no.4
• /
• pp.133-141
• /
• 2012

A new depth filter media was designed and samples of flat sheet as well as cartridge assembly were prepared and tested to evaluate the filtration performance and compare with the commercial product. The arrangement of the depth filter media layers is important to reach the optimal filtration parameters like filter pressure drop, particle collection efficiency and dust holding capacity. Initially, both flat sheet samples of new media and commercial product have been tested using standard test units. Tests with new depth filter media cartridges of various pleat count were conducted in order to find the optimal pleat count which would represent the lowest pressure drop. These tests give an insight on how the pleat count and the assembly configuration affect the performance of the depth filter media cartridge. By comparing the samples with a commercial product we could confirm relatively high filtration performance of the sample cartridge with pleat count 150 made of new depth filter media. The cartridge with the same pleat count exhibits better performance without the outer mesh.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.42.1-42.1
• /
• 2015

We model the Spectral Energy Distribution (SED) of Class 0 protostar L1527 IRS using a radiative transfer code RADMC-3D. In addition to the photometry data from literatures, we include the Herschel/PACS data which well covers the far-infrared SED peak of L1527 IRS, providing precise constraints to the density structure and other physical properties of its circumstellar envelope. Previously, Tobin et al. (2013) presented a dust continuum modeling results using a rotating and infalling envelope (Terebey and Shu, & Cassen 1984 ; TSC envelope), which originally describes a power-law density profile (${\rho}{\propto}r-{\alpha}$) with the power-law index (${\alpha}$) of 1.5. However, we find that Herschel/PACS data are better fitted with a shallower power-law density profile. This smaller power-law might be attributed to a inner envelope. Thus, we fit the SED of L1527 IRS with a Bonnor-Ebert sphere, which is a combination of the inner flat-topped and the outer power-law (${\alpha}=2$) density profiles. This Bonnor-Ebert sphere is often used to explain the density profile of prestellar cores, which is considered the earliest stages of star formation. The well-fitted SED with a Bonnor-Ebert sphere suggests that L1527 IRS might have collapsed from a Bonnor-Ebert sphere rather than a singular isothermal sphere.

• Publications of The Korean Astronomical Society
• /
• v.32 no.1
• /
• pp.313-315
• /
• 2017

We present physical properties of $24{\mu}m$ galaxies detected by AKARI and Spitzer and their evolution between redshifts 0.4 < z < 2. Using multi-wavelength data from X-ray to radio observations in NEP Deep Field (for AKARI) and Subaru/XMM-Newton Deep Field (for Spitzer), we derive photometric redshift, stellar mass, star-formation rate (SFR), dust extinction magnitude and rest-frame luminosities/colors of the $24{\mu}m$ galaxies from photometric SED fitting. We infer the SFRs from rest-frame ultraviolet luminosity and total infrared luminosity calibrated against Herschel photometric data. For both survey fields, we obtain complete samples with stellar mass of > $10^{10}M_{\odot}$ and SFR of > $30M_{\odot}/yr$ up to z = 2. We find that specific SFRs evolves with redshift at all stellar masses in NON-power-law galaxies (non-PLGs) as star-formation dominant luminous infrared galaxies (LIRGs). The correlations between specific SFR and stellar mass in the Spitzer and AKARI galaxy samples are well consistent with trends of the main sequence galaxies. We also discuss nature of PLGs and their evolution.

• The Korean Journal of Mycology
• /
• v.20 no.1
• /
• pp.77-82
• /
• 1992

Researches were carried out to find the optimal conditions of carbon sources, nitrogen sources and pH for the maximum production of sporophore of Lentinus edodes. Dextrin, aspartic acid and pH 4.0 were the best conditions for yield of sporophore by using replacement culture technique. The production of sporophore was stimulated by addition of 0.8% triacylglycerol in NS medium. Coffee waste was chosen for the best substrate among the poplar, oak, white aspen saw dust and coffee waste. Increased growth of mycelim and yield of sporophore was obsewed by adding tannin up to 0.1% as substrate.

• International Journal of Railway
• /
• v.9 no.2
• /
• pp.41-45
• /
• 2016

In this paper, a study on the efficiency improvement of the magnetic levitation train using the LIM (Linear Induction Motor) was presented. The maglev train has the advantage of being environmentally friendly since much less noise and dust is produced. However, due to structural limitation, compared to a rotating induction motor, linear induction motor, the main propulsion engine of the maglev train has a relatively greater air gap and hence has the lower operation efficiency. In this paper, the relationship between the operating condition of the train and the slip frequency has been investigated to find out the optimum slip frequency that might improve the efficiency of the magnetic levitation train with linear induction motor. The slip frequency is variable during the operation by this relationship only within a range that does not affect the levitation system of the train. After that, the comparison of the efficiency between the conventional control method with the slip frequency fixed at 13.5[Hz] and the proposed method with the slip frequency variable from 9.5[Hz] to 6.5[Hz] has been conducted by simulation using Simplorer. Experiments of 19.5[ton] magnetic levitation trains owned by Korea Institute of Machinery and Materials were carried out to verify the simulation results.