• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.2
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• pp.96-105
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• 1997

In this paper, A new design method of fuzzy modeling is presented for the model identification of nonlinear complex systems. The proposed FPNN(Fuzzy Polynomial Neural Network) modeling implements system structure and parameter identification using GMDH(Group Method of Data Handling) method and linguistic fuzzy implication rules from input and output data of processes. In order to identify premise structure and parameter of fuzzy implication rules, GMDH method and regression polynomial fuzzy reasoning method are used and the least square method is utilized for the identification of optimum consequence parameters. Time series data for gas furnace and those for wastewater treatment process are used for the purpose of evaluating the performance of the proposed FPNN modeling. The results show that the proposed method can produce the fuzzy model with higher accuracy than other works achieved previously.

• Textile Coloration and Finishing
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• v.12 no.1
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• pp.25-31
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• 2000

In order to decolorize disperse dyes by using biological treatment process, a strain which has potential ability to degrade disperse dyes was isolated from natural system. To increase the removal efficiency of decolorization in the aqueous solutions, the optimal condition of decolorization by this strain was investigated, and continuous plant test was also developed. The optimal culture conditions of temperature and pH were found to be 4$0^{\circ}C$ and 8.5~9, respectively. When yeast extract was mixed with polypeptone at the mixing ratio of 1:1 as a nitrogen source, decolorization efficiency was highest(93%) among the nitrogen sources. The strain to be screened was excellent to adjust to pH, and it seems to be have ability to control pH needed to growth. The optimal culture conditions in concentration of $MgSO_4\cdot{7H}_2O$ and $KH_2PO_4$ were 0.1%(w/v) and 0.2%(w/v). The result of continuous plant process using wastewater was as following : $COD_{Mn}$ removal efficiency was over than 50%, and this strain was very excellent in decolorization-efficiency for the wastewater of Taegu dyeing complex.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.34-40
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• 1994

Industrial Complex in Ulsan is one of the most important areas in the nation. It includes ship building, automobile production, petroleum industry, non-metalic industry, and related industries. However, water for drinking and industry use has been and will be short seriously. Thus available drinking water sources were searched. By rebuilding the two existing dams 20m higher than the present levels, $500,000m^3/day$(for 200days) of water sources may be produced. Additional volume of $13,000m^3/day$(for 200days) can be obtained by a number of small dam construction in the vincity area. Underground water of about $50,000m^3/day$ may also be available. The total of $680,000m^3/day$ could be produced in Ulsan area, which is enough for the population of 1,200,000 in Ulsan area even after year 2011. This newly searched volume of water may be free from pollution. Raising the dam levels may also prevent Ulsan city from chronic flooding problems. Additional advantage is that as much as the newly developed water resources can be supplied to the industrial complexes.

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.617-623
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• 2010

It is the most important subject to figure out characteristics of the wastewater inflows of sewerage treatment plant(STP) when situation models are applied to operation of the biological processes and in the automatic control based on ICA(Instrument, Control and Automation). For the purposes, real-time influent monitoring method has been applied by using on-line monitoring equipments for the process optimization in conventional STP. Since, the influent of STP is consist of complex components such as, COD, BOD, TN, $NH_4$-N, $NO_3$-N, TP and $PO_4$-P. MRA2(Microbial Respiration Analyzer 2), which is capable of real-time analyzing of wastewater characteristics is used to overcome the limitations and defects of conventional online monitoring equipments in this study. Rapidity, accuracy and stability of developed MRA2 are evaluated and compared with the results from on-line monitoring equipments for seven months after installation in Full-scale STP.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.467-472
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• 2012

In this study, water quality and acute toxicity using Daphnia magna were analyzed to investigate the eco-toxicological substances identified as statistical analysis and propose a management plan for the effluent of Banwol industrial complex, Ansan, Gyeonggi-do. Cu, Zn, F, Mn concentrations in the effluent far exceeded the US standards to protect the aquatic ecosystem and eco-toxicity values were 5 ~ 22 TU. However, concentrations of heavy metals significantly decreased after Ansan public wastewater treatment plant operating a biological treatment and toxicity values were 0 TU. Zn, Cr, F and Cu in the effluent showed very strong and strong positive correlations with eco-toxicity values, respectively. Regression analysis resulted in an equation between toxicity and Zn, TU = $4.884{\times}Zn$ (mg/L) -0.391 showing Zn concentration should be managed less than 0.285 mg/L to keep the eco-toxicity (TU) less than 1.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.535-546
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• 2011

The study area investigated in this research is Hwaseong city, Gyeonggi-Do where small scale development is currently in progress. For the last three years, we carried out the environmental and ecological assessment by using data from The Ministry of Environment and Han River Basin Environmental Office. Most of development works in Hwaseong city, Gyeonggi-Do are small scale developments which are related with factory and distribution complex based on individual laws and regulations. However, environmental and ecological assessment is not being sufficiently reflected beforehand. Especially, because the development takes place mainly in the outskirts of the city, the fine forest is continuously being damaged. We analyzed changes in green zone area caused by the developments. As a result, the percentage of original green zone was decreasing while the percentage of artificial green zone was increasing. We should maintain the percentage of the original green zone in order to conserve natural environment. In the past three years, the damage of the DGN (Degree of Green Naturality) 7 area that has high conservative value was little, but, there was serious damage in the area of DGN 6. In order to conserve natural environment, political and institutional investigation should be seriously carried out for mitigation of environmental and ecological damages.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.481-489
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• 2016

Method of characteristic(MOC) has been widely used as a transient analysis technique for pressurized pipeline systems. There are substantial studies using MOC for the water hammer triggered through instantaneous valve closures, pump stoppage and pump startup for pipelines systems equipped with a centrifugal pump. Considering restrictions of MOC associated with courant number condition for complicated pipeline systems, an impulse response method(IRM) was developed in the frequency domain. this study implements the impact of centrifugal pump using transfer function in frequency domain approach. Using pump performance curve and the affinity law, this study formulated transfer functions which relate complex pressure head at upstream of pump system to that of downstream location. Simulations of simple reservoir-pump-valve system using IRM with formulated transfer function were similar to those obtained through MOC.

• Journal of Korean Society on Water Environment
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• v.21 no.3
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• pp.236-241
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• 2005

The purpose of this study is to find out the source(s) and distribution of boron in Nak-dong River. In the year of 2002, the boron has been adopted as a toxic constituent for Korean drinking water standard. In this study, the analytical samples were collected at 11 stations in March, June, September and December 2002. These samples were analyzed by inductively coupled plasma-mass (ICP-MS) method. The recovery, relative standard deviation and method detection limit of the ICP-MS method for boron was $89{\sim}111.3%$, $2.21{\sim}3.81%$ and $5{\mu}g/L$, respectively. The distribution of boron was ranged $65{\sim}155{\mu}g/L$ in March, $26{\sim}125{\mu}g/L$ in June, $22{\sim}140{\mu}g/L$ in September and $50{\sim}162{\mu}g/L$ in December. The higher levels of boron were found at Kum-ho river nearby the industrial complex, which seemed to be greatly affected by domestic sewages and wastewater from the upper streams. Thus, the concentration of boron and that of other components showed strong statistical correlation in this area. In the Nak-dong River, industrial wastewater and domestic sewages is thought to be the sources of boron.

• Clean Technology
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• v.28 no.1
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• pp.63-78
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• 2022

Electronics industrial wastewater treatment facilities release organic wastewaters containing high concentrations of organic pollutants and more than 20 toxic non-biodegradable pollutants. One of the major challenges of the fourth industrial revolution era for the electronics industry is how to treat electronics industrial wastewater efficiently. Therefore, it is necessary to develop an electronics industrial wastewater modeling technique that can evaluate the removal efficiency of organic pollutants, such as chemical oxygen demand (COD), total nitrogen (TN), total phosphorous (TP), and tetramethylammonium hydroxide (TMAH), by digital twinning an electronics industrial organic wastewater treatment facility in a cyber physical system (CPS). In this study, an electronics industrial wastewater activated sludge model (e-ASM) was developed based on the theoretical reaction rates for the removal mechanisms of electronics industrial wastewater considering the growth and decay of micro-organisms. The developed e-ASM can model complex biological removal mechanisms, such as the inhibition of nitrification micro-organisms by non-biodegradable organic pollutants including TMAH, as well as the oxidation, nitrification, and denitrification processes. The proposed e-ASM can be implemented as a Water Digital Twin for real electronics industrial wastewater treatment systems and be utilized for process modeling, effluent quality prediction, process selection, and design efficiency across varying influent characteristics on a CPS.

• Membrane Journal
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• v.24 no.5
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• pp.350-357
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• 2014

Pressurized MF membranes are used to remove suspended solid and colloidal materials of wastewater treatment plant effluent as the pretreatment of RO in reuse water production process. Membrane operation data and pollutants removal efficiency are investigated using 100 t/d scale pilot plant in J wastewater treatment plant located in Namyangju city. 40 LMH flux of pressurized MF membrane are obtained in various turbidity and temperature condition. Coagulation of dissolved organic enables flux improvement of MF from 40 LMH to 60 LMH. Pressure drop of 1st RO elements rapidly increased after long-term pause, which is because the complex contamination of organic matter and ionic substances of pluming systems.