• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.265-270
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• 1972

An attempt was made in this study to investigate the possibility of processing squid along with pork into an intermediate moisture food, as an acceptable new item in Korea. To obtain a palatable and low cost product, portions of mixture consisting of equal amounts of ground squid and pork were cooked in soy sauce for 20 min, soaked in glycerol for 20 min at $80^{\circ}C$, and then air dried for 90 min at $60^{\circ}C$. During storage for 42 days in saturated humidity incubator at $37^{\circ}C$, the total microbial counts of the products packaged in polyethylene (0.05 mm), polypropylene (0.05 mm) and plastic laminated aluminum foil were decreased from 230 per gram to 40, 20 and 10 per gram respectively. In another long range storage test of 6 months, the results paralleled the above trends. Even though the TBA value of the samples increased during the storage, it was not so serious as to damage on the organoleptic quality of this product. The results indicate that stored product was as acceptable as the freshly prepared one.

• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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• pp.24-31
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• 2013

The motion of living organisms such as birds, fishes, and insects, has been analyzed for the purpose of the design of MAV(Micro Air Vehicle) and NAV(Nano Air Vehicle). In this research, natural motion was considered to be applied to the determination of the geometry and motion of AUV(Autonomous Underwater Vehicle). The flapping motion of a number of hydrofoil shapes in AUV was studied, and at the same time, the optimization of the hydrofoil shape and flapping motion was executed that allow the highest thrust and efficiency. The harmonic motion of plunging and pitching of NACA 4 digit series models, was used for the numerical analysis. The meta model was made by using the kriging method in Optimization method and the experimental points of 49 were extracted for the OA(Orthogonal array) in DOE(Design of experiments). Parametric study using this experimental points was conducted and the results were applied to MGA(Micro Genetic Algorithm). The flow simulation model was validated to be an appropriate tool by comparing with experimental data and the optimized shape and motion of AUV was turned out to produce highest thrust and efficiency.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.148-154
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• 2005

Ground-source (Geothermal) heat pump (GSHP) systems can achieve a higher coefficient of performance than conventional air-source heat pump (ASHP) systems. However, GSHP systems are not widespread in Japan because of their expensive boring costs. The authors have developed a GSHP system that employs the cast-in-place concrete pile foundations of a building as heat exchangers in order to reduce the initial boring cost. In this system, eight U-tubes are arranged around the surface of a cast-in-place concrete pile foundation. The heat exchange capability of this system, subterranean temperature changes and heat pump performance were investigated in a foil-scale experiment. As a result, the average values for heat rejection were 186${\sim}$201 W/m (for pile, 25 W/m per Pair of tubes) while cooling. The average COP of this system was 4.6 while cooling; rendering this system more effective in energy saving terms than the typical ASHP systems. The initial cost of construction per unit for heat extraction and rejection is ${\yen}$72/W for this system, whereas it is f300/W for existing standard borehole systems.

• Journal of Ocean Engineering and Technology
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• v.9 no.2
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• pp.75-82
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• 1995

The free surface effects on the aerodynamic performance of 2-D wings are investigated based on the potential flow approximation. The wing is represented b source and vortex distributions on the wing surface. The steady free surface effect is taken into account by source distribution on the free surface and the velocity potentials of air and water flows are obtained. Using three different techniques, namely, positive image method, inverse image method and source distribution method, numerical results are obtained for wave elevation, pressure distribution and lift coefficient with various foil sections. The wave elevation calculated by the inverse image method is shown to be very small even at higher speeds so that the free surface effect on the performance of wings is regraded negligible. However, the wave elevations by the positive image method and source distribution method are relatively high at higher speeds and accordingly the free surface effects on wings can not be neglected.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.56-63
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• 2013

This study was aimed at developing and evaluating a diffusive sampling method using a barium hydroxide solution as an absorbent for measuring carbon dioxide ($CO_2$) in ambient air. The collected $CO_2$ concentration was calculated by the change of conductivity resulted in the reaction of $CO_3{^{2-}}$ and $Ba^{2+}$ in aqueous solution. The sampling rate for the diffusive sampler was determined 0.218 mL/min, as obtained from the slope of the linear correlation between the $CO_2$ mass collected by the diffusive sampler and the time-weighted $CO_2$ concentration with the active sampling method. The unexposed blank sampler sealed in aluminium foil-polyethylene laminated packets has remained stable during at least one-month storage period. A good correlation was observed between the diffusive sampler and active sampler with a coefficient of determination of 0.956. This diffusive sampler would be suitable for the indoor $CO_2$ concentration monitoring.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.340-345
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• 2000

This study was carried out to analyze the light and thermal environment in model greenhouse using infrared absorption film as shading screen and to compare with the case of no shading and using general shading screen such as aluminum foil-backed film, black polyethylene film and thermal blanket. PPFD(photosynthetic photon flux density) of inside the model greenhouse under infrared absorption film was increased by 22% than under general shading screen on the average. And temperature of inside air under infrared absorption film was 2$^{\circ}C$ lower than under general shading screen on the average. So, it is expected that infrared absorption film is useful as shading screen.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.593-598
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• 2000

In this paper the critical speed analysis and design sensitivity investigation are carried out with an APU(auxiliary power unit) gas turbine having a spline shaft connection. The DDM(direct differential method) is directly applied to formulate the critical speed design sensitivity problem of a general nonsymmetric-matrix rotor-bearing system. The design sensitivity analysis have shown that the critical speed change rate to the support modeling of the spline shaft connection point is extremely negligible, and thereby its design uncertainty is lifted. It has also been confirmed that the critical speeds up to the 4th are not sensitive to the design stiffness coefficients of 4-main bearings or supports, including two air foil bearings. Further, the critical speed change rate to the shaft-element length have shown quantitatively that the spline shaft has some limited influence on the 4th critical speed.

• Journal of agriculture & life science
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• v.43 no.3
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• pp.27-34
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• 2009

Green tea was prepared by soaking 1.5 g of green tea leaves into 100 mL of distilled water at $75^{\circ}C$ for 5 min. The green tea was stored at three different conditions - (A) green tea was stored at not-artificially excluding natural light condition, at natural air condition, and without addition of vitamin C; (B) green tea was stored at artificially excluding natural light condition by wrapping a vial with aluminium foil, at nitrogen filling up condition, and with addition of 30 mg/100 mL of vitamin C; and (C) green tea was stored at artificially excluding natural light condition by wrapping a vial with aluminium foil, at nitrogen filling up condition, and without addition of vitamin C. After 28 days of storage at $4^{\circ}C$, the chemical quality of the green tea was evaluated. Total phenolic contents of (A), (B), and (C) green tea decreased to 71.50, 73.88 and 75.07%, respectively, after storing for 28 days compared to those of beginning state. DPPH radical scavenging activities of (A), (B), and (C) green tea were 87.87, 92.93 and 88.39%, respectively. Epigallocatechin gallate (EGCG), the main active compounds of green tea, contents of (A), (B), and (C) green tea were 130.61, 136.47 and 4.34%, respectively. The results indicated that light, air condition, and vitamin C were significantly important to the chemical quality of green tea during storage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.245-245
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• 2009

l-D nanostructured materials have much more attention because of their outstanding properties and wide applicability in device fabrication. Copper oxide(CuO) has been realized as a p-type metal oxide semiconductor with narrow band gap of 1.2 -1.5eV. Copper oxide nanostructures can be synthesized by various growth method such as oxidation reaction, thermal evaporation thermal decomposition, sol-gel. and Mostly CuO nanowire prepared on the Cu substrate such as Copper foil, grid, plate. In this study, CuO NWs were grown by thermal oxidation (at various temperatures in air (1 atm)) of Cu metal deposited on CuO (20nm)/$SiO_2$(250nm)/Si. A 20nm-thick CuO layer was used as an adhesion layer between Cu metal and $SiO_2$

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2170-2172
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• 1999

A low energy large aperture(LELA) pulsed electron beam generator of a cold cathode type has been developed for environmental applications, for example, waste water cleaning, flue gas cleaning, and pasteurization etc. The operational principle is based on the emission of secondary electrons from cold cathode when ions in the plasma hit the cathode, which are accelerated toward exit window by the gradient of an electric potential. We have fabricated the LELA electron beam generator with the peak energy of 200keV and beam diameter of 200mm and obtained the large aperture electron beam in air. The electron beam current density has been investigated as a function of glow discharge current, accelerating voltage and radial distribution in front of the exit window foil. The plasma density and electron temperature have been measured in order to confirm the relation with the electron beam current density. We are going to upgrade the LELA electron beam generator in the electron energy, electron beam current and stability of operation for various applications.