• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.190-194
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• 2004

This paper shows the application of fuzzy system for a modeling of nonlinear biochemical process. A wastewater treatment process for nitrogen removal in a sequencing batch reactor (SBR) is presented and fuzzy systems with different consequent polynomials in the fuzzy rules to model and identify the oxidation reduction potential (ORP) of the process are introduced. The paper compares, analyzes the results of fuzzy modeling, and shows the nonlinear process can be modeled reasonably well by the present scheme.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.595-601
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• 2005

In this research, effects of water circulation on phosphorus release from sediment into water body were studied. Sediments sampled at the Daechung Lake were used for the column experiments with circulation and non-circulation conditions. Deaeration coefficient, $K_1$ and reaeration coefficient, $K_2$ of non-circulation condition were 0.133 and 0, respectively, while $K_1$ and $K_2$ for circulation condition were 0.46 and 0.018, respectively. Oxidation Reduction Potential (ORP) showed a linear relationship with dissolved oxygen (DO) when DO is over 2 mg/L. Phosphorus concentration induced by phosphorus release from sediment was highly dependent upon DO, ORP, and pH. Under anaerobic condition, phosphorus release rate was higher for $Fe^{2+}$-bounded phosphorus compared to that of $Ca^{2+}$-bounded phosphorus.

• Journal of Animal Environmental Science
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• v.3 no.2
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• pp.115-123
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• 1997

This study was conducted to investigate the removal effect of malodorous substances of piggery wastes by air injection. With 7% of TS weight of artificial piggery wastes, this study focused on the changes of the concentration of VFAs, H2S during treatment period of 14 days. As a results of this study, air injection volume for removal of malodorants in this study was 150$m\ell$ / min$.$l$.$Under this condition, we found the concentrations of VFAs, H2S, NH3 have very high relationship with the pH, ORP, BOD, {{{{ { NH}`_{4 } ^{+ } }}-N. Especially, the concentration of Volatile Fatty Acids, one of most offensive odorants and one of BOD compounds were depended on ORP which can be controled by air injection in artificial piggery wastes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.548-549
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• 2007

과거 PCB 제조의 주된 화제는 다양한 산업분야의 발전을 위해 한정된 시간 안에 좀 더 많은 PCB를 양산하는 기술 개발에 집중되어 있었지만, 현재는 비정상적인 공정 상태를 파악함으로써 제조 공정 환경에서의 오류를 줄여 전체 수률을 높이는 방법에 시선을 돌리고 있다. PCB 에칭의 경우 에칭 용액의 상태를 실시간으로 모니터링 하는 것이 중요하다. 본 논문에서는 기존 애칭용액의 상태를 판단할 때 사용되는 ORP 센서 대신, RGB 센서를 이용하여 실시간으로 용액의 상태를 모니터링 할 수 있는 시스템을 개발 하였다. 개발된 시스템을 이용하여 기존 ORP 시스템과의 비교 분석을 및 RGB 센서률 이용한 모니터링 방법이 ORP 센서를 이용한 방법 보다 좀 더 쉽고 정확하게 에칭 액의 상태를 모니터링할 수 있다는 것을 확인 하였다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.1-14
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• 2008

Eight comprehensive oceanographic cruises on a squared $30{\times}30\;km$ area have been made to investigate the short and long-term impacts on the water qualities due to the sand mining operations at Exclusive Economic Zone (EEZ) in the central Yellow Sea from 2004 to 2007. The area was categorized to 'Sand Mining Zone', 'Potentially Affected Zone', and 'Reference Zone'. The investigation covered suspended solids, nutrients (nitrate, nitrite, ammonium, phosphate), and chlorophyll-a in seawater and several parameters such as water temperature, salinity, pH, and ORP. Additionally, several intensive water collections were made to trace the suspended solids and other parameters along the turbid water by sand mining activities. The comprehensive investigation showed that suspended solids, nitrate, chlorophyll-a and ORP be sensitively responding parameters of seawater by sand mining operations. The intensive collection of seawater near the sand mining operation revealed that each parameter show different distribution pattern: suspended solids showed an oval-shaped distribution of the north-south direction of 8 km wide and the east-west direction of 5 km wide at the surface and bottom layers. On the other hand, phosphate showed so narrow distribution not to traceable. Also ammonium showed a limited distribution, but its boundary was connected to the high nitrate and chlorophyll-a concentrations with high N/P ratios. From the last 4 years of the comprehensive and intensive investigations, we found that suspended solids, ammonium, nitrate, chlorophyll-a, and ORP revealed the sensitive parameters of water quality for tracing the sand mining operations in seawater. Especially suspended solids and ORP would be useful tracers for monitoring the water qualities of remote area like EEZ in Yellow Sea.

• Microbiology and Biotechnology Letters
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• v.35 no.1
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• pp.73-80
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• 2007

Biofilm media was equipped in two-compartmented wastewater treatment bioreactor which was separated by porcelain septum. DC 2.0 volt of electric potential was charged to anodic (oxidative) biofilm media (ABM) to induce oxidation potential but not to that of carbon (neutral) biofilm media (CBM) that was used for control test. Biofilm structure, biomass variation, Off variation and wastewater treatment efficiency in the bioreactor equipped with ABM (ABM-bioreactor) and CBM (CBM-bioreactor). Time-coursed variation of biofilm structure forming on surface of ABM and CBM was observed by scanning electron microscopy. The biofilm growing on ABM was dispersed on surface and was not completely covered the media but the biofilm growing on CBM was continuously increased and finally covered the media. The ORP of CBM was decreased to 100 mV, which was reciprocally proportional to the biomass growth. However, the ORP of ABM was about 800 mV, which was maintained during operation for about 60 days. The treatment efficiency of COD in the ABM bioreactor was 2 times higher than those in the CBM bioreactor. From these results, we proposed that electrochemical oxidation potential charged to biofilm media may inhibit formation of biofilm extremely condensed and activate bacterial cell metabolism.

• Food Science and Preservation
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• v.10 no.1
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• pp.99-105
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• 2003

This study was carried out to investigate the efficacy of surface sterilization and the physicochemical properties of electrolyzed water manufactured from various electrolytic diaphragm and electrolyte. Physical properties of electrolyzed water manufactured from the diaphragm system were the most effective at the following conditions; the distance between diaphragms was 1.0 mm and the supplying rate of 20% NaCl was 6 mL/min. The ORP, HClO content and pH at above conditions were 1,170 mV, 100 ppm and 2.5, respectively. And two stage electrolyzed system was more effective than one stage electrolyzed water manufactured from non-diaphragm system, with 4 mL/min supplying rate of 20% NaCl, was similar to the most effective diaphragm system. But ORP, HClO content and pH were abut 800 mV, 200 ppm and 9 level, respectively. Sealed electrolyzed water could be preserved more than one month at room temperature with ORP of 750 mV in non-diaphragm system and 1,150 mV in diaphragm system, and HClO content of 100 ppm. Twelve kinds of microorganism tested were sterilized within 30 seconds from initial total counts of 10$\^$5/∼10$\^$6/cfu/ml by electrolyzed water. Though the ORP and HCIO contents of electrolyzed water manufactured from various electrolyte were higher in order of NaCl>KCl>CaCl$_2$, there were no difference between the electyolytes in the efficacy of sterilization. Salmonella typhi and Vibrio Proteolyticus were also sterilized by electrolyzed water manufactured from elctrolytes of NaCl CaC1$_2$and KCl

• Resources Recycling
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• v.26 no.2
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• pp.18-24
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• 2017

The $FeCl_3$ solution has been used as an etchant for etching of metal. It is necessary to reuse the etching solution because waste $FeCl_3$ etchant generated after use has provided environmental and economic problems. In this study, HCl was mixed with the $FeCl_2$ solution and then $H_2O_2$ was added into the mixed solution to oxidize the $Fe^{2+}$. During the oxidation process, oxidation-reduction potential (ORP) was measured and the relationship between ORP and oxidation ratio was investigated. As a result, this study found that the ORP was increased with increasing the concentration of HCl and $H_2O_2$, while the ORP is decreased with oxidation progress. Such a behavior was in good agreement with Nernst's equation. Also, the oxidation efficiency reached about 99% when a sufficient amount of HCl and $H_2O_2$ were added.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09b
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• pp.145-148
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• 2003

본 논문에서는 이차다항식을 이용하여 생화학적인 공정의 모델링을 행한다. SBR 반응조에서 질소제거를 위한 수처리 공정이 제시되었으며, 이 공정의 ORP값을 모델링하고 동정하기 위해 서로 다른 형태의 선형모델이 소개되었으며 결과를 비교하고 분석한다 시뮬레이션 결과로부터 합리적이고 효율적으로 모델링 될 수 있음을 검증한다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.221-225
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• 2004

This paper shows the application of artificial intelligence technique such as polynomial neural network in modeling and identification of sequencing batch reactor (SBR). A wastewater treatment process for nitrogen removal in the SBR is presented. Simulation results have shown that the nonlinear process can be modeled reasonably well by the Present scheme which is simple but efficient.