• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.285-286
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• 2011

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.304-308
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• 2005

본 연구는 발포수지 공정에 사용되는 가스벤트를 신발중창 금형에 자동으로 교환하는 장치에 관한 것이다. 가스벤트는 폴리우레탄과 같은 소재를 이용한 신발 미드솔 발포시 발생되는 가스를 제거하기 위한 다공질 소자로서 신발금형 상부에 삽입된다. 가스벤트는 소모성 부품으로 일정주기마다 교환이 필요하나 작업공정상 수작업에 어려움이 많아 자동화된 교환시스템이 요구된다. 하지만 삽입되는 신발중창 금형과 가스벤트간은 유격이 거의 없으므로 본 연구에서는 신발 중창 금형의 손상을 방지하고 보다 신속한 교환을 위해 가스벤트 삽입 및 추출 홈의 위치정보를 영상을 통해서 구하고, 얻어진 영상에 대한 위치 데이터를 기계적 위치 추적 시스템의 데이터로 피드백 하여 홀의 중심 위치에서 가스벤트를 삽입 및 추출하여 자동으로 교환하는 장치를 구현하였다. 영상 처리는 패턴 매칭 기법을 이용하여 홀의 중심점을 구하였고, 이를 PLC로 전송하여 기계 작동 제어 및 XY플로터를 정밀 제어하여 공정이 진행되게 하였다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.129-136
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• 2005

There should not be ion exchange resin particles in S/G sludge. The suspicious spherical resin particles observed in S/G sludge sample were characterized for particle size distribution under optical microscope using the micro-technique, for element analysis by the electron probe micro analysis (EPMA), and for molecular identification by the IR spectroscopy The particle sizes are distributed from 1 to 200 ${\mu}m$ for the sludge, while 40 to 500 ${\mu}m$ for the spherical resin particles. The results of the elemental analysis showed different major impurities: Si, Al, Mn, Cr, Ni, Zn and Ti for the sludge particles, while Si, Cu, Zn for the spherical resin particles. However, both particles contain Fe as a matrix of hematite ($Fe_{3}O_4$). IR spectrum of the spherical particles was quite different from that of ion exchange resins used in S/G system. These results indicate that the spherical particles are not related to ion exchange resin particles and formed by the process of the sludge formation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.657-658
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• 2011

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.58-63
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• 2003

폐쇄형 묘생산 시스템(closed system for transplants production)은 자연광이 투과되지 않도록 단열재로 구성되어 있어 시스템 내부와 외부의 공기, 물, 열 등의 교환이 기본적으로 제한된다. 또한 식물 생육에 필요한 관수량, 내부에 적절한 습도를 유지시켜 주기 위한 가습량 및 공조기구에 의한 제습량 등이 시스템 내에서 평형을 이루며 순환한다. (중략)

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.248-254
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• 2009

Budgets of fresh water, salt, DIP and DIN in the Youngsan river estuary were estimated seasonally in order to clarify the characteristics of material cycling and flux of nutrients with a simple box model. Inflow volumes of freshwater into system was approximately $36.481{\times}10^6{\sim}663.634{\times}10^6m^3/month$ and existing water mass of freshwater in system calculated by salt budget was approximately $2.515{\times}10^6{\sim}5.812{\times}10^6m^3$. Mean residence time of freshwater was calculated to be about 0.26~2.03 day. water exchange $1,248{\times}10^6{\sim}9,489{\times}10^6m^3/month$ assumed with salinity between estuary and adjacent ocean. Inflow mass of DIN and DIN were approximately 76.63~1,149.91 ton/month and 2.91~61.22 ton/month, respectively. Residence times of DIP and DIN were calculated to be 0.45~1.10 day and 0.28~1.92 day, respectively. The ratio of water residence time versus DIP, DIN residence time was calculated that freshwater residence time was longer than DIP, DIN residence time except for summer season. Thus, We assume that circulation of Nutrients in the system will happen rapidly except for summer season. Specially DIP in Winter could assume to outer input source existence because of seawater inflow in system and high DIP concentration in open sea.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.104-113
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• 1986

The ion exchange behaviour of the $Cs^{+1},\;Sr^{+2},\;and\;Th^{+4}$ in the system of $Cs^{+1},\;Sr^{+2},\;Th^{+4},\;and\;7Cl^{-}-H^{+}$ from Dowex HCR-W2, was examined in the loading and elution processes. $Th^{+4}$ was slowly adsorbed through the entire contact time between resin and solution and $Cs^{+1}\;and\;Sr^{2+}$ were adsorbed fast for the first few minutes of contact time. Because of the strong affinity of $Th^{+4}$, the longer contact time was allowed, the less amount of $Cs^{+1}\;and\;Sr^{2+}$ was adsorbed on the resin. The peak concentration of the resin phase $Cs^{+1}$ in the solution concentration of $Cs^{+1}:Sr^{+2}:Th^{+4}$ in the ratio of 2 : 2 : 1 in normality with total normality of 0.1N was produced at about 4 minutes of contact time and the peak time for $Sr^{+2}$ was 20 minutes. The loaded ions were eluted using hydrochloric acid. The loaded $Cs^{+1}$ was eluted at the low eluent concentration of less than 0.1N with less than 5% contamination of $Sr^{+2}$. The loaded $Th^{+4}$ was eluted at the high eluent concentration of greater than 1N. The best eluent concentration for eluting $Th^{+4}$ was 4N.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1132-1141
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• 1996

Heterogeneous cation exchange membrane(HCEM) was prepared with LLDPE(Linear Low Density Poly-ethylene) as binder, powdered cation exchange resins($diameter{\leq}149{\mu}m$) as ion-exchange material and glycerol as additive for electrodialysis and electrodeionization system. The weight ratio of (binder/ion exchange)/glycerol was (60%/40%)/5%, (55%/45%)/5%, (50%/50%)/5% and (40%/60%)/5%. The characterization of prepared HCEM was evaluated on mechanical, electrochemical, morphology and ion permeable properties. It was compared with commercial membrane. Electrochemical properties of HCEM of (50%/50% )/5% were very similar to value of IONPURE(commercial membrane), in which ion exchange capacity, ion transfer number and membrane resistance were to be 1.733meq/g, 0.96 and $16.08{\Omega}/cm^2$, respectively. Ion permeability of the membrane was better than that of IONPURE membrane. Compared with IONPURE membrane, the HCEM had a higher tensile strength and lower elongation and modulus, in which HCEM had tensile strength of $62.33kg/cm^2$, elongation of 87.42% and modulus of $658.53kg/cm^2$. The HCEM of (50%/50% )15% was optimum combination.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.1000-1007
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• 2011

For enlarging the applications of microstereolithography, the use of diverse materials is required. In this study, the material switching system (MSS) for projection microstereolithography apparatus is proposed. The MSS consists of three part; resin level control, resin dispensing control, and vat level control. Curing characteristic of materials used in fabrication has been identified. Through repeated fabrication of test models, the critical fabrication error is investigated and a possible solution to this error is suggested. The developed system can be applied to improve the strength of microstructure and extended to fabricate an array of microstructures with multiple materials.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.15-20
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• 2003

During operation process of SIES(Selective ion exchange system) at Kori Unit 2, it was impossible to remove radionuclides such as ion form and Ag-110m, etc., because activated carbon and ion exchange resin of this system are fouled easily by suspended solids and oils in liquid radwaste that was flowed in this system. In this study, an experiment to improve quality of water which was flowed in SIES was performed. and design data of Scale-up pretreatment process were secured. Also, each module design for Microfiltration and Nanofiltration unit of the pretreatment process for SIES was performed.