• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1354-1363
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• 1993

Optical methods were developed to examine their feasibility for quality evaluation of peanut with pod. Surface color and internal quality of peanut were measured without contact. The surface color of peanut was measured by light reflectance at a region of visible wavelengths. Its characteristic was high correlated with a visual grading of peanut. A trial machine for the color grading of peanut was developed using an optical sensor and it was considered to compare with the visual grading. The spectral reflectance at a region of near infrared wavelengths from 1,200 to 2,500nm was measured , and the chemical components of peanut were related to spectral reflectance at special wavelengths. The protein, fat and moisture contents of peanut were estimated by the near infrared methods. An infrared imaging method was developed to evaluate the internal quality of peanut with pod. As thermal characteristic of peanut with pod was deeply related to internal quality , the quality of peanut can be evaluated by temperature changes on the surface of peanut. Measurement of surface color, near infrared reflectance and thermal imaging were shown to be very effective in grading of peanut with pod.

• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.52-52
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• 2006

Many spacecraft failures and anomalies have been attributed to energetic electrons in the Earth's magnetosphere. While the dynamics of these electrons have been studied extensively for several decades, the fundamental question of how they are accelerated is not fully resolved. Proposed theories have not been successful in explaining fast high energy increase such as REE (Relativistic electron enhancement). In this presentation, we show observations of energetic electron precipitation measured by the Korean satellite, STSAT-1 which simultaneously detect (100ev - 20 keV) and (170 - 360 keV) energy electrons at the 680 km orbit, when the RES event observed at the geosynchronous orbit on October 13, 2004. STSAT-1 observed intense electron precipitation in both energy ranges occurred in the midnight sector clearly demonstrating that electrons having wide energy band are injected from the plasma sheet. To make the balance between loss and injection, the injected electron flux should be also large. In this situation, the injected electrons can be trapped into the magnetosphere and produce REE, though they have low e-folding energies. We propose this plasma sheet injection might be the primary source of relativistic electron (1 MeV) flux increases.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.263-269
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• 2009

The purpose of this study is to propose an appropriate criterium for proper sound insulation service preventing school classrooms from aircraft noise. The guideline of noise level for school facility by Korean school health law is less than Leq 55 which is less stringent than that of other countries. It has been reported that many students are annoyed and disturbed for their works when they are exposed to the noise level over Leq 55. It is desirable to modify this guideline of indoor noise level for school classroom. The noise level of classroom of which windows are opened was measured relatively high in case the school is located at the outside of the official area damaged by aircraft noise. In order to minimize the influence of aircraft noise on the school classrooms in the vicinity of domestic airport, it is necessary to improve the present criteria of WECPNL 75 for the establishment of the area damaged by aircraft noise from WECPNL 70.

• ETRI Journal
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• v.31 no.4
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• pp.478-480
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• 2009

The design of a CMOS clamped-clamped beam resonator along with a full custom integrated differential amplifier, monolithically fabricated with a commercial 0.35 ${\mu}m$ CMOS technology, is presented. The implemented amplifier, which minimizes the negative effect of the parasitic capacitance, enhances the electrical MEMS characterization, obtaining a $48{\times}10^8$ resonant frequency-quality factor product ($Q{\times}f_{res}$) in air conditions, which is quite competitive in comparison with existing CMOS-MEMS resonators.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.183-187
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• 2000

Removal rate of nitrogen compound containing swine wastewater was 97 percent in case of high loading rate treatment of swine wastewater at studies for process development using soil microorganism. Minimum hydraulic retention time(HRT) for nitrification process was 11 days and solid retention time was 25 days. Nitrification was between 5 and 11 days but this time $NO_2-N$ was remained. Reactor condition was injured to nitrosomonas according to pH, $NO_2\;^--N$, and $NH_3\;^--N$ concentration but this condition was recover to pH controlling.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.177-182
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• 2000

Removal rate of swine wastewater containing organic matter was 99 percent in case of high loading rate. The studies of swine wastewater treatment aim to development of process using soil microorganism. Microorganism was devoted to improve the treatment efficiency of the process. Biochemical oxygen demand (BOD) concentration of treated swine wastewater was under 150 mg/L in anaerobic reactor. Also, value of km and Y were $0.73\;hr^{-1}$ and 0.433 g/VSS/g BODrm/d at microorganism of post aeration tank in anaerobic reactor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.4
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• pp.486-493
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• 1997

Experimental investigations on the comparison of developments between transient jets and evolving jet diffusion flames have been made in initial injection period. To achieve this experiment, an ignition technique using a residual flame as the ignition source is devised. High speed Schlieren visualizations, and measurements including jet tip penetration velocities and jet widths of the primary vortex are employed to examine the developing processes for several flow conditions. It is seen that the developing behaviors in the presence of flame are greatly different from those in transient jet, and thus the flow characteristics in the transient part are also modified. The discernible differences are shown to consist of the delay of the rollup of the primary vortex, the faster spreading after the rollup due to exothermic expansion, and the survival of only a primary vortex. The growth of primary vortex in the transient jet is properly explained through an impulsively started laminar vortex prior to the interaction. It is also found that the jet tip penetration velocity varies with elapsed time and an increase in Res gives rise to a higher tip penetration velocity.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.565-570
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• 1997

High levels of extracellular phospholipase $A_2$ (Plase $A_2$) associated with inflammatory process in man and animal models have been extensively reported elsew here. Thus, a logical approach to the treatment of inflammatory diseases should involve the inhibitors of Plase $A_2$. To develop new Plase $A_2$ inhibitors from natural products, two hundred crude drugs were screened using group II PLA$A_2$ inhibitory activity. Among them, methanol extract of 5 medicinal plants such as, Raphani Semen, Moutan cortex radicis, Arecae semen, Caryophylli Cortex and Betulae Cortex inhibited more than 90% of PLase $A_2$ activity at a concentration 2.5${\mu}g/ml$. Then, 10 methanol extracts sample were transferred into organic solvents, PLase $A_2$ inhibitory effects were found mainly in CHCl3 and EtoAc fractions.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2221-2230
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• 2016

Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 kW prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.68-75
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• 2001

Photopolymerization, the utilization of electromagnetic radiation(or light) as the energy source for polymerization of functional monomers, oligomers is the basis of important commercial processes with broad applicability, including photoimaging and RV curing of coatings and inks. The objective of this study is to investigate the characteristics of environmental fraternitive photopolymerization of methyl methacrylate(MMA). This work is the first step to continue further research about alkyl methacrylate. The experiment was done in aqueous solution under the influence of photo-initiator concentration(0.05-0.25mol/l), light intensity (5000-9000 ${\mu}J/cm^2$) and monomer concentration(2-6mol/l). Methyl methacrylate was polymerized to high conversion ratio using hydrogen peroxide($H_2O_2$) and the kinetics model we have obtained is as follows. $R_p=k_p[S]^{0.41}[M]^{0.62}[L]^{2.45} exp(53.64/RT$). The differential method of thermogravimetric analysis(Friedman method) was used to obtain value of activation energy on decomposition reaction. The average value of it res 45.4Kca1/mol.