• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.307-314
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• 1998

The response of water stree under high and low temperatures, was shown differently according to the longer the suspension period of water supply. Leaf photosynthetic rate(LPS), leaf water potential(WP), relative leaf water content and relative soil water content were lower. At the higher temperatures, the percentate of reduction in LPS and WP was greater than at low temperatures. It is suggested that evaporation rate should be higher in the high temperature than the lower temperature. Also leaf water potential was lower at high temperature than at low temperature. After the 9 th day of treatment , LSP was remarkably reduced at high temperature, but the reduction of LPS was not significant at low temperature. Solidago virga-aurea var. asiatic that maintained LPS of 3rd day after treatment was more strong than other varieties at low temperatures. The silting and curling of leaves were observed symptoms of stress on the 9th day at the both temperatures. The leaves of aster scaber and Ligularia fischeri turned red on the 9th day after treatment at low temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.108-116
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• 2009

In this paper, we develop an ELM(Extreme Learning Machine) based short-tenn water demand prediction algorithm which solves overfitting problem of MLP(Multi Layer Perceptron) and has quick training time. To show effectiveness of proposed method, we analyzed time series data collected in A water treatment plant at Chung-Nam province during $2007{\sim}2008$ years and used the selected data for the verification of developed algorithm. According to the experimental results, MLP model showed 5.82[%], but the proposed ELM based model showed 5.61[%] with respect to MAPE, respectively. Also, MLP model needed 7.57s training time, but ELM based model was 0.09s. Therefore, the proposed ELM based short-term water demand prediction model can be used to operate the water treatment plant effectively.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.2
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• pp.43-52
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• 1994

In this paper, the unit processes in the typical water treatment plant, which need to be expanded because the water demand is over the existing water treatment capacity in the near future, were carefully examined to upgrade the water treatment plant. The models were installed in the fields as a distorted model based upon the hydraulic similitudes. The models having the constant discharge ratio in the unit processes between the model and the prototype were installed as two units to compare the treatment efficiencies. The capacity of the individual unit, which is a model of the prototype of $250,000m^3/day$ capacity, was $24m^3/day$. In the mixing and flocculation experiments, the mixing intensity of flocculators G was selected as the main experimental item. The optimal mixing intensities G, which are 65/sec for experimental discharge of $1m^3/hr$ and 85/sec for experimental discharge of $1.3m^3/hr$, are identified based upon the comparison the relative turbidity removal efficiencies. Also, the outlet weir loading was selected as the main experimental item in the sedimentation process. Through the continuous experiments with the main experimental items of the mixing intensity of flocculators G and the outlet loading of the weir in the sedimentation basin, about 20% upgrading compared to the existing water treatment capacity was obtained.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.676-681
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• 2008

The evaluation of the effluent water quality of sewage treatment plant is one of the most important factor in calculating total maximum daily loads (TMDLs). Current method to calculate 95% upper limit of effluent water quality of sewage treatment plant assuming normal distribution of data needs to be implemented in case of non-normal distribution. We have investigated the applicability of percentile ranking method as a non-parametric statistical analysis in case of non-normal distribution of data.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.279-290
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• 2004

Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.372-379
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• 2010

Macrophomina phaseolina causing charcoal rot was isolated from sesame seeds (cvs. Giza 32 and Shandawel-3) collected from different localities of Assiut, Sohage and El-Minia Governorates. The fungus was found in the highest frequently in samples collected from Assiut Governorate followed by Sohag and finally EL Minia Governorate. The obtained isolates were different in their virulence on the tested sesame cvs. Also, they differed in their growth nature including colony color and sclerotial production. The color of colonies of the pathogen seem to be correlated with density of sclerotial formation. Aqueous extracts of Majorna, Wild chamomile, Geranium oil and Nees plants were highly toxic to tested isolates of M. phaseolina, in vitro. On the other hand the rest of the tested aqueous extracts had no effect. Under greenhouse conditions in 2005 and 2006 seasons, soaking seeds of sesame before sowing in aqueous extracts of Eucalyptus, Nerium, Ocimum and Roesmary plants decreased the disease incidence. Aqueous extracts of Eucalyptus and Ocimum were the most effective treatment. Dipping sesame seeds in hot water at $60^{\circ}C$ for 5 minutes increased seed germination of Giza 32 and Shandawel-3 cvs. followed by $55^{\circ}C$, $50^{\circ}C$ and $45^{\circ}C$, while $40^{\circ}C$ treatment resulted the lowest seed germination rate. Dipping sesame seeds in hot water at different temperature before planting decreased seed, seedling and charcoal rots. Soaking seeds in hot water at $60^{\circ}C$ increased greatly plant height and decreased seed, seedling rot and charcoal rot followed by $55^{\circ}C$ and $50^{\circ}C$, under greenhouse condition.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.123.2-123
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• 2001

It is difficult to determine the feeding rate of coagulant in the water treatment plant, due to nonlinearity, multivariables and slow response characteristics, etc. To deal with this difficulty, the neuro-fuzzy system and the genetic-fuzzy system were used in determining the feeding rate of the coagulant. The fuzzy system is excellently robust in multi-variables and nonlinear problems. Therefore it uses basic algorithm, but it is difficult to construct of the fuzzy parameter such as the rule table and the membership function, Therefore we made the neuro-fuzzy system and the genetic-fuzzy system with the fusion of learning algorithms and compared the performance of the two fuzzy systems. To apply these algorithms, we made the rule table, membership function from the actual operation data of the water treatment plant. We determined optimized feeding rate of coagulant using the fuzzy operation, and also compared ...

• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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• pp.56-60
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• 2013

Non-conventional oil resources such as shale gas are becoming increasingly important and have drawn the attention of several major oil companies all over the world. Nevertheless, the market-changing growth of shale gas production in recent years has resulted in the emergence of environmental and water management challenges. This is because the water used in the hydraulic fracturing process contains large amount of pollutants including ions, organics, and particles. Accordingly, the treatment of this flowback water from shale gas plant is regarded as one of the key technologies. In this study, we examined the feasibility of membrane distillation as a treatment technology for the water from shale gas plants. Direct contact membrane distillation (DCMD) is a thermally-driven process based on a vaper pressure gradient across a hydrophobic membrane, allowing the treatment of feed waters containing high concentration of ions. Experiments were carried out put in the lab-scale under various conditions such as membrane types, temperature difference, flow rate and so on. Synthetic feed water was prepared and used based on the data from literature. The results indicated that DCMD is suitable for treating not only low-range flowback water but also high-range flowback water. Based on the theoretical calculation, DCMD could have over 80% of recovery. Nevertheless, organic pollutants such as oil and surfactant were identified as serious barriers for the application of MD. Further works will be required to develop the optimum pretreatment for this MD process.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.68-74
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• 2004

A blast furnace slag(BFS) has been used as a filter medium for the treatment of domestic waste waters during the period of 9-month. More than 90% of phosphorus was removed while the hardness of the treated water increased by 5 times and the pH was significantly raised from 6.8 to 10.8. The high hardness and pH of the treated water indicated dissolution of BSF by the sewage. The experimental results suggest that BFS could be utilized for the removal of phosphorus in the waste water treatment plant using aquatic plants and gravels.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.138-146
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• 2006

The characteristics of backwash and concentrate discharges depend upon the quality of the water being treated and the net recovery of the membrane system. This paper is to indicate a design methods on the capacities of residuals treatment facilities in membrane processes for drinking water. We operated a demonstration membrane plant with a recovery rate of 90% for designing G-water treatment plant. We investigated on design parameter (optimum coagulant dosage and surface loading rate etc.) to design efficiently the residuals treatment facilities. The settling test was conducted with 1m columns dosing PACl to kaolin and membrane residuals under the experimental condition that discharge permit was under a 60mg/L. When the quantity of membrane residuals was $1,575m^3/day$, the estimated results for 1st thickener demonstrated the surface loading rate of 14.4m/day, detention time of 5.83hr, available depth of 3.5m.