• Title/Summary/Keyword: Park Yoo-jeon

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Effects of Various Eggshell Treatments on the Egg Quality during Storage

  • Park, Y.S.;Yoo, I.J.;Jeon, K.H.;Kim, H.K.;Chang, E.J.;Oh, H.I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.8
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    • pp.1224-1229
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    • 2003
  • The combined effects of washing, sanitization and coating of eggshell on the physical and microbiological quality during storage were evaluated at $4^{\circ}$ and $30^{\circ}C$. The interior qualities of the eggs were assessed by weight changes, yolk index, albumen index, Haugh unit value, and microbial contamination of egg shell and egg white during 30 days of storage in untreated, washed, or sanitized and mineral oil-coated eggs. The results suggest that these changes were faster in higher temperature ($30^{\circ}C$) than lower temperature ($4^{\circ}C$) storage, and washed eggs deteriorated faster than untreated eggs. The sanitized and coated eggs maintained the best quality during storage in all parameters measured. The shelf-life of washed, sanitized and coated eggs could be extended 4-5 fold compared to that of washed or untreated eggs.

The Theoretical Study of the Measuring Thermal Diffusivity of Semi-Infinite Solid Using the Photothermal Displacement

  • Jeon, PiIsoo;Lee, Kwangjai;Yoo, Jaisuk;Park, Youngmoo;Lee, Jonghwa
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1712-1721
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    • 2004
  • A method of measuring the thermal diffusivity of semi-infinite solid material at room temperature using photothermal displacement is proposed. In previous works, within the constant thickness of material, the thermal diffusivity was determined by the magnitude and phase of deformation gradient as the relative position between the pump and probe beams. In this study, however, a complete theoretical treatment of the photothermal displacement technique has been performed for thermal diffusivity measurement in semi-infinite solid materials. The influence of parameters, such as, radius and modulation frequency of the pump beam and the thermal diffusivity, was studied. We propose a simple analysis method based on the zero -crossing position of real part of deformation gradient and the minimum position of phase as the relative position between two beams. It is independent of parameters such as power of pump beam, absorption coefficient, reflectivity, Poisson's ratio, and thermal expansion coefficient.

Design and Implementation of CDMI Interfaces for Cloud Data Management (클라우드 데이터 관리를 위한 CDMI 인터페이스의 설계 및 구현)

  • Ahn, Minje;Jeon, Inbae;Son, Ingook;Li, He;Park, Yonghun;Lim, Jongtae;Bok, Kyoungsoo;Yoo, Jaesoo
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.297-298
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    • 2013
  • 클라우드 컴퓨팅 산업의 발달로 클라우드 데이터를 관리하기 위한 연구들이 활발하게 진행되고 있다. 그러나 현재 연구되고 있는 다양한 형태의 클라우드 컴퓨팅 플랫폼들은 기술적, 정책적으로 개방성을 띄지 않아 사용자의 구축 환경에 따른 상호 운용성을 보장하지 못한다. 본 논문에서는 클라우드 환경에서 데이터 생성, 검색, 갱신, 삭제하기 위해 CDMI 국제 표준을 준수하는 저장소 인터페이스를 설계하고 구현한다. 이러한 인터페이스는 특별한 제약없이 클라우드 저장소를 구축하거나 사용하려는 개발자에게 필요한 기능을 제공한다.

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Identification of Novel Regulators of Apoptosis Using a High-Throughput Cell-based Screen

  • Park, Kyung Mi;Kang, Eunju;Jeon, Yeo-Jin;Kim, Nayoung;Kim, Nam-Soon;Yoo, Hyang-Sook;Yeom, Young Il;Kim, Soo Jung
    • Molecules and Cells
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    • v.23 no.2
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    • pp.170-174
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    • 2007
  • High-throughput subcellular imaging is a powerful tool for investigating the function of genes. In order to identify novel regulators of apoptosis we transiently transfected HeLa cells with 938 hypothetical genes of unknown function, and captured their nuclear images with an automated fluorescence microscope. We selected genes that induced greater than 3-fold increase in the percentage of apoptotic nuclei compared with vector-transfected cells. The full-length genes C10orf61, MGC 26717, and FLJ13855 were identified as candidate proapoptotic genes, and their apoptotic effects were confirmed by DNA fragmentation ELISAs and Western blotting for caspase-7 and PARP. We conclude that a subcellular image-based apoptotic screen is useful for identifying genes with proapoptotic activity.

Development of High Efficiency PDP Driven by RF Pulses

  • Choi, J.P.;Jeon, W.G.;Kang, J.;Lim, G.S.;Kim, O.D.;Kim, H.Y.;Song, J.W.;Yoo, E.H.;Park, M.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.169-170
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    • 2000
  • The conventional AC PDP has a relatively low efficiency which is close to 1.5 lm/W. If the AC sustain period is replaced by the RF sustain period, due to oscillating and low electric field, almost 60% of the supplied energy is spent by Xe excitation [1]. The efficiency of RF PDP can be $4{\sim}5$ times higher than that of AC PDP. In this paper, we will present the RF PDP that is a new type of PDP. A new display method in PDP using RF pulses is suggested and applied on a 4-inch-diagonal Panel (hereinafter 4" panel). Even though there were many researches in RF discharge, there was not enough research for display application. Now we propose the RF PDP that is a new display field and we will expect to do more research in this field.

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Carbon-Supported Ordered Pt-Ti Alloy Nanoparticles as Durable Oxygen Reduction Reaction Electrocatalyst for Polymer Electrolyte Membrane Fuel Cells

  • Park, Hee-Young;Jeon, Tae-Yeol;Lee, Kug-Seung;Yoo, Sung Jong;Sung, Young-Eun;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
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    • v.7 no.4
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    • pp.269-276
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    • 2016
  • Carbon-supported ordered Pt-Ti alloy nanoparticles were prepared as a durable and efficient oxygen reduction reaction (ORR) electrocatalyst for polymer electrolyte membrane fuel cells (PEMFCs) via wet chemical reduction of Pt and Ti precursors with heat treatment at $800^{\circ}C$. X-ray diffraction analysis confirmed that the prepared electrocatalysts with Ti precursor molar compositions of 40% (PtTi40) and 25% (PtTi25) had ordered $Pt_3Ti$ and $Pt_8Ti$ structures, respectively. Comparison of the ORR polarization before and after 1500 electrochemical cycles between 0.6 and 1.1 V showed little change in the ORR polarization curve of the electrocatalysts, demonstrating the high stability of the PtTi40 and PtTi25 alloys. Under the same conditions, commercial carbon-supported Pt nanoparticle electrocatalysts exhibited a negative potential shift (10 mV) in the ORR polarization curve after electrochemical cycling, indicating degradation of the ORR activity.

Evaluation of Chromatic-Dispersion-Dependent Four-Wave-Mixing Efficiency in Hydrogenated Amorphous Silicon Waveguides

  • Kim, Dong Wook;Jeong, Heung Sun;Jeon, Sang Chul;Park, Sang Hyun;Yoo, Dong Eun;Kim, Ki Nam;An, Shin Mo;Lee, El-Hang;Kim, Kyong Hon
    • Journal of the Optical Society of Korea
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    • v.17 no.5
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    • pp.433-440
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    • 2013
  • We present an experimental and numerical study of spectral profiles of effective group indices of hydrogenated amorphous silicon (a-Si:H) waveguides and of their chromatic-dispersion effect on the four-wave-mixing (FWM) signal generation. The a-Si:H waveguides of 220-nm thickness and three different widths of 400, 450 and 500 nm were fabricated by using the conventional CMOS device processes on a $2-{\mu}m$ thick $SiO_2$ bottom layer deposited on 8-inch Si wafers. Mach-Zehnder interferometers (MZIs) were formed with the a-Si:H waveguides, and used for precise measurement of the effective group indices and thus for determination of the spectral profile of the waveguides' chromatic dispersion. The wavelength ranges for the FWM-signal generation were about 45, 75 and 55 nm for the 400-, 450- and 500-nm-wide waveguides, respectively, at the pump wavelength of 1532 nm. A widest wavelength range for the efficient FWM process was observed with the 450-nm-wide waveguide having a zero-dispersion near the pump wavelength.

Design and Cold Flow test of a Multi-injector Engine using Hydrogen Peroxide/Kerosene (과산화수소 케로신을 추진제로하는 다중 인젝터 설계 및 수류실험)

  • Kim, Ki-Woo;Jeon, Jun-Su;Park, Jin-Ho;Ko, Young-Sung;Kim, Yoo;Kim, Sun-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.95-98
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    • 2010
  • A multi-injector rocket engine using high concentrated hydrogen peroxide and kerosene as the oxidizer and fuel was designed and fabricated. Six coaxial swirl injectors were mounted on the mixing head and flow analysis in the manifold was performed to minimize stagnation and recirculation zones. Finally, uniformity of mass flow rate and spray pattern was evaluated by cold flow tests and the mixing head design process was successfully verified the results.

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Ground Firing Test of a 75 Ton Class Engine System for KSLV II and its Structural Vibration Responses (75톤급 액체로켓엔진 지상연소시험 및 진동응답 분석)

  • Kim, Jin-Hyuk;Jeon, Seong Min;Park, Jongyoun;Yoo, Jaehan;Jeong, Eunhwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.928-929
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    • 2017
  • A 75 ton class liquid rocket engine has been developed for KSLV II. Ground firing tests of the rocket engine were conducted to characterize and quantify its structural vibration under combustion testing environments. In this study, evaluation of dynamic response characteristics of the engine system was presented to verify its structural integrity and structural design during ground firing tests.

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Design and Fabrication of Self-aligned Parallel-plate Type Micromirror Array (자기정렬에 의한 평판전극 마이크로미러 어린이의 설계와 제작)

  • Yoo, Byung-Wook;Kim, Min-Soo;Jin, Joo-Young;Jeon, Jin-A;Park, Jae-Hyong;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.150-151
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    • 2007
  • We present an one-axis parallel-plate type of bulk micromachined torsional micromirror array with single crystalline silicon (SCS) fabricated on the glass substrate. Structurally, bottom electrodes (amophous silicon) in this mirror are DRIEed along the aluminum mirror patterns on SCS, which are self-aligned with mirror plates. Tracing the history of the micromirror study, we found that few papers have been published on research for uniform driving voltages based upon the tilting direction. If there is a slight misalignment during anodic bonding between top (mirror plate) and bottom electrodes, the non-uniformity of driving voltage will be led depending on two different tilting direction. This paper discusses how much the pull-in voltages can be different due to misalignment between two electrodes. Moreover, We achieve uniform pull-in voltage regardless of misalignments in photolithography and anodic-bonding between two individual layers.

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