• Journal of Environmental Science International
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• v.10 no.2
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• pp.105-111
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• 2001

Improvement of water quality and Investigation of bacterial characteristics have been conducted in a pilot plant using biological activated carbon (BAC) in water treatment process at the downstream of the Nakdong River. Most of water control parameters were highly improved after passing through BAC. Approximately 54% of dissolved organic carbon was removed in coal-based BAC process. Bacterial biomass and bacterial production appeared $9.8{\times}10^8 CFU/g and 7.1mg-C/m^3$.hr in coal-based BAC, respectively. Predominant bacteria species grown in BAC were identified as Pseudomonas, Flavobacterium, Alcaligenes, Acinetobacter and Aeromonas species. Particularly Pseudomonas vesicularis was dominant in both coal-based and coconut-based BACs, while Pseudomonas cepacia was dominant in wood-based BAC.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2041-2043
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• 2000

Ozone is widely used to sterilize food and tap water because ozone is a strong oxidizer. To date, it has been difficult to dissolve a high concentration of ozone gas in water because the large size of the bubbles limits the contact area between the ozone gas and liquid water. The measurements of dissolved ozone can be used to control water quality and ozone dosage. Therefore the dissolved ozone measurement of most interest is that of residual ozone at the discharge point of a particular treatment chamber.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.89-95
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• 1996

This paper describes a fuzzy controlled pre-chlorination technique for purifying the pulluted raw water in water purification lants. For the purpose of obtaining the high quality water, the appropriate pre-chlorine dosage rate has to be continuously adjusted according to a change in quality of a intake raw water, weather, solar nergy mount, temperature and etc. Therefore, the method of expressing an expert's empirical knowledge cumulated from his past carrier by fuzzy reasoning and the fuzzy controller design technique is necessary.In this paper fuzzy membership functions and rules accordingto emprircal knowledge and experimental field data were obtained, And also fuzzy cintriller design using four feedforward components for the determination of pre-chlorine dosage rate and four feedback ones for the compensation of its dosage rate with residual chlorine and its change rate, was executed.

• Korean Journal of Plant Resources
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• v.12 no.1
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• pp.10-19
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• 1999

The water status of Pinus densiflora and P. koraiensis was observed after the treatment of simulated acid rain for every month August 1997 to March 1998. Both of the species showed increase of dry weight, water saturation deficit and epidermis transpiration after treatment of simulated acid rain (pH 3.5) for first three months. On the contrary, water content was decreased in both the species after three month of simulated acid rain treatment. The effect of simulated acid rain, however, became weaker after that and no big difference was observed after seven month of treatment. Water potential of the leaf of both species became lower than that of the control(pH 5.6) after seven month treatment of simulated acid rain. The cuticle layers of the epidermis and florins ring were damaged seriously and the size of the gap between stomata became bigger after the treatment of simulated acid rain.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.143-147
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• 2012

The rapid growth of camera technology can provide various types of information which was not previously provided. Furthermore, IP camera which has rapid data transfer rate and high resolution particularly provide a lot of useful functions beyond the existing simple surveillance capabilities. We are developing Real-Time Face Recognition Access Control System based on the camera technology, and improvement of face detection and recognition algorithms are vitally needed to realize that system. In this paper, we proposes a method to improve the computing speed and detection rate by adding new features to the existing Viola-Jones detection algorithm.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.96-99
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• 2001

The fatigue life of support bearings is one of the most critical factors for the performance of a control rod driving mechanism. They are operated at high temperature and high pressure and especially lubricated with dramatically low viscosity water. The support bearing is made of standardized 440C stainless steel, and it supports thrust load including the weight of the driving system and external force. Friction and wear characteristics of this material operating under severe lubrication condition is not well known yet, although it is expected to be changed with respect to temperature and boundary pressure. So the friction characteristics are investigated in sliding conditions using the reciprocating tribometer which can simulate the operating conditions. Highly purified water is used as lubricant, and the water is heated up and pressurized. Friction farce on the reciprocating specimens is monitored by the load cells. The results of the experiments are presented in this paper.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.115-120
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• 1986

This experiment was carried out to develop long-term preservable meat products by controlling a water activity which has a potential inhibitory effects on the growth of microorganism and germination of spore. For this purpose the accuracy of instrument for the measurement of water activity, electric hygrometer was used for this study as well as water activity of final products were investigated according to the various amounts of different kinds of additives. Spore of Bacillus spp, Clostridium sporogenes and Cl. botulinum were inoculated to the meat products with different aw and their growth states in $25^{\circ}C$ were observed to find out the lowest aw which inhibit their growth (aw 0.950).

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.265-269
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• 2017

Because of abrupt changes for velocity in water, transient flow is occurred in practical life. To reduce and avoid the high or low pressure of pipe network system, various surge protection facilities are used to prevent the risk in pipe network system. Especially, we focused on study not only preventing positive and negative pressure but also selecting adequate equipment for high pressurized pipelines. Several critical cases were considered by undertaking a steady state hydraulic study and transient dynamic simulation and we suggested that the surge vessel of various surge protection system was recommended to control high and low pressures on pipeline system in perspective.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.131-139
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• 2000

The effects of the simulated acid rain on the growth response and water status of Glycine soja was observed in 2 months-old seedlings. The seedlings were treated with acid rain(pH 3.5), three times per week. Glycine soja showed significant reduction in the total length, total weight, dry weight, water contents and top/root ratio after treatment of simulated acid rain(pH 3.5) for 56 days. The growth of shoot was more susceptible to acid rain than that of roots. On the contray, Number of lateral roots, water saturation deficit and epidermis transpiration was higher than that of control(pH 5.6) after 56 days treatment of simulated acid rain.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.4
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• pp.13-19
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• 2018

The Effects of hot water supply temperature on indoor thermal characteristics for floor radiant heating system in residential apartment were researched by computer simulation. The parametric study on hot water supply temperatures with different outdoor air temperatures was done with regard to energy performance and control characteristics, respectively. As a result, the maximum overshoot of indoor air temperature and energy consumption were reduced by adjusting the hot water supply temperatures with outdoor air temperatures.