• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.206-214
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• 2005

This study was initiated to evaluate efficiencies of suspenced-growth processes(CAS; Conventional Activated Sludge, MLE; Modified Ludzack-Ettinger) and hybrid process(Modified-Dephanox) on removal of organic matter(C), nitrogen(N) and phosphorus(P) in municipal wastewater. M-Dephanox process was designed to improve the performance of Dephanox process on denitrification efficiency. As the results, removal efficiencies of total chemical oxygen demand(TCOD), total nitrogen(T-N) and total phosphorus(T-P) in M-Dephanox process, which is hybrid process, were 12,3, 18.6 and 28.2% higher than those in MLE, which is suspended-growth process. The better removal efficiencies of TCOD, T-N and T-P in M-Dephanox than those in MLE result that M-Dephanox is not only hybrid or multi-sludge process but also process using biosorption mechanism which is possible to use organics in denitrification, effectively. Ammonia removal efficiency in nitrification reactor of M-Dephanox was 96.7% at short hydraulic retention time(HRT) of 2 hr which was 3 hr more short HRT than that(HRT 5 hr) reported in other related papers. This indicates that M-Dephanox process can reduce HRT of whole process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.218-225
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• 2020

This study analyzed the priorities of the cross-compliance items of public-benefit direct payment using an Analytic Hierarchy Process and Fuzzy Decision Making Analysis. The valuation criteria are policy efficiency, farm acceptability, and feasibility, and the valuation targets are the basic and additional cross-compliance items. The survey was performed by targeting 50 experts from each class, and conducted for about a month starting from the beginning of July 2019. The results show that the weight of the valuation criteria is higher in the order of farm acceptability, feasibility, and policy efficiency. Compliance with PLS standards, compliance with disposal standards of waste vinyl and pesticides, soil testing, compliance with toxic substance standards, education, etc. are comparatively evaluated to be higher cross-compliance items in basic cross-compliance. Disposing of an abandoned well, jointly collecting and disposing of agricultural by-products, common area care and cleaning, maintenance of empty houses and poor facilities, growing green manure crops during the fallow period, etc. are comparatively evaluated to be higher cross-compliance items for the additional cross-compliance. The results of this study are expected to contribute to the government's policy related to the cross-compliance of public-benefit direct payment.

• Journal of Korea Water Resources Association
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• v.45 no.8
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• pp.767-782
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• 2012

Accumulation of sediment within pipelines, manholes, and other components of urban sewer systems can have a bad influence on sewerage arrangements, such as the resistance of the passage of flows, the cause of urban flooding and the premature operation of combined sewer overflows, and the inevitable pollution of watercourses. Therefore, it is necessary to understand the movements and sedimentation of sediment loads in combining junction manholes by experiments. In this study, hydraulic experimental apparatus which can change the manhole shapes (square, circle) were installed to measure deposited sedimentation quantity. The quantity of deposited sediment loads was measured by different conditions, for instance, the inflow conditions of sediment (continuous and certain period), the amount of inflow sediment, and the variation of inflow pipe of sediment. The combining junction manhole that was set up a inclined benching have the considerable effect of reduction of sedimentation in manholes without apropos of the change of manhole shapes. Therefore, the improved manhole could be increased the drainage capacity of sewerage arrangements in urban sewer systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.4
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• pp.159-171
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• 1990

The purpose of this study was development and application of a multiple box model for long term prediction and control of water quality in estuary reservoir. The model was composed of one main model and two sub models for hydrology and water quality. Water quality constituents for modeling were temperature, chlorophyll-a, BOD, DO, N, and P. The model had been applied to Asan reservoir, and the reservoir had been devided into three boxes-two boxes for a upper layer and one box for a lower layer-to represent stratification. The model appeared satisfactory in representing long term trend of water quality variations by comparing measured and simulated results. According to the application of the model to study alternatives for water quality improvement to deal with increase in future pollution load, use of non-phosphorous detergent for chlorophyll-a, advanced sewage treatment for BOD and T-N, reduction of livestock waste for T-P were evaluated as more effective ones than any others, respectively.

• Korean Journal of Childcare and Education
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• v.8 no.5
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• pp.89-110
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• 2012

The purpose of this study is analyzing the preference of young children for the outward appearance of a teacher-aided humanoid robot. The subjects of this study were 180 kindergarten children who were 4 years old. Ninety five children among the subjects were male, and 85 children were female. The instrument used for this study consisted of 15 questions that involved 3 domains; figure, face, and practical use of robot. The major findings of the study were as follows: First, young children preferred a smooth and intimate robot, and one that had a similar size to them. Second, young children preferred a more characteristic face with big eyes. Third, young children preferred a robot which had a contoured body Fourth, young children preferred a robot which had two legs or tank wheels. Fifth, young children preferred a robot that could play with them and be manipulated by them.

• Journal of the Korean Institute of Intelligent Systems
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• v.5 no.4
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• pp.41-55
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• 1995

In this paper, an optimal idenfication method using fuzzy-neural networks is proposed for modeling of nonlinear complex systems. The proposed fuzzy-neural modeling implements system structure and parameter identification using the intelligent schemes together wlth optimization theory, linguistic fuzzy implication rules, and neural networks(NNs) from input and output data of processes. Inference type for this fuzzy-neural modeling is presented as simplified inference. To obtain optimal model, the learning rates and momentum coefficients of fuzzy-neural networks(FNNs) are tuned automatically using improved modified complex method and modified learning algorithm. For the purpose of its application to nonlinear processes, data for route choice of traffic problems and those for activateti sluge process of sewage treatment system are used for the purpose of evaluating the performance of the proposed fuzzy-neural network modeling. The results show that the proposed method can produce the intelligence model with higher accuracy than other works achieved previously.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.2
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• pp.26-33
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• 2011

Recently, the use of buried glass fiber reinforced plastic (GRP) pipes is widespread and ever increasing trend in the industry. GRP pipes are attractive for use in harsh environments, such as for the collection and transmission of liquids which are abrasive and/or corrosive. The structural behavior of a GRP pipes buried under the ground is different from that of a rigid one made of concrete or clay, for example. A GRP pipe buried under the ground is deflected circumferentially by several percent and the stresses in the pipe are mainly compressive stresses. A GRP pipes has been introduced by a number of manufacturers for selection and used by underground pipeline designers. In all cases, the modified Spangler's equation is recommended by these manufacturers for predicting the ring deflection of these pipes under dead and live loads. In this paper, the ring deflection of buried GRP pipe is evaluated and discussed based on the result of analytical investigation.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.57-66
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• 2014

The leachate recirculation anaerobic digestion system has the advantage of stable methane gas generation compared with existing one phase systems. In this study, an anaerobic digestion system fed with source separated food waste from school cafeteria was studied with different food waste/inoculum anaerobic sludge volume ratios (8:2, 3:7, 2:8). From this study, leachate recirculation anaerobic reactor with food waste/inoculum anaerobic sludge volume ratio of 2:8 that is 9 gVS/L of OLR(Organic Loading Rate) had the highest gas production. Also this anaerobic reactor showed daily decrease of H2S and NH3 contents in produced gas. Average biogas yield was 1.395 m3 Biogas/kg VS added. Other anaerobic reactors with food waste/inoculum anaerobic sludge volume ratio of 8:2 and 3:7 stopped methane gas production.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.330-337
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• 2018

The Korean Eutrophication Index($TSI_{ko}$) was estimated using water quality monitoring data of eight main sites in the SoOoak River watershed. The environmental characteristics of rivers were classified and evaluated using the $TSI_{ko}$ for each factor calculated by COD, T-P, and Chl-a. There is a good condition for the algae to grow due to shallow water depth, inflow of non-point source pollution during rainfall, influx of sewage treatment effluent and increase of residence time. It shows trophic state more than mesotrophication year round. Especially, in case of Chuso point, which is the inflow point of Daecheong Lake, the water quality deteriorated due to hydraulic characteristics and showed the eutrophic state. Therefore, it is necessary to establish the measures to improve the water quality through the precise monitoring of SoOak River.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.455-465
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• 2014

This study focuses on some institutional improvement for revitalization of change in building use of officetel to lifestyle lodging industry. First as analysis method, this study establishes a failure factor for change in building use of officetel to lifestyle lodging industry. Second, analyzes an urgent importance to improve it in aspect of a legal institution or management for revitalizing a change of building use of officetel to lifestyle lodging industry. As a result, a failure factor of change in building use from officetel to lifestyle lodging industry is deducted in 4 articles with 13 detailed index. As a result of AHP, 'existing contractor's 100% agreement condition' is the first place, 'commercial /semi-residential area in zoning' is the second place, 'relative cleanup zone' is the fourth place, 'late changes of building use by a complex licensing procedure' is the fifth place, 'operational risk of consignment' is the sixth place, 'deficiency in publicity of related institution' is the eighth place, 'lack of concept in lifestyle lodging industry of building code' is the ninth place, 'basic constructional condition such as parking lot sewage and fire protection system' is the tenth plce, 'installation of ventilation facility' is the eleventh place, 'installation of bathroom and shower room in each room' is the twelfth place, 'installation of kitchen facility' is the thirteenth place.