• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.900-904
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• 1991

It is important and difficult to control the steam temperature in the once through boiler. Generally, steam temperature of once through boiler not only is controlled by boiler spray water flow, but also is influenced by feed water flow and fuel flow. So we have to make the same gain of fuel flow controller and feed water flow controller. This paper is shown the design and test of steam temperature and feed water flow control system for once through boiler in pusan thermal power plant.

• 제어로봇시스템학회논문지
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• 제14권3호
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• pp.221-225
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• 2008

This paper presents a self-tuning controller for pressurized water reactor (P.W.R.). This self-tuning controller includes two substantial steps, such as parameter identification and control-law building in each cycle. Extended least square algorithm is used for parameter identification, Kalman filter is used for state estimation, and discrete Riccati equation is used for optimal control. Effectiveness of this algorithm is shown through computer simulation and sensitivity analysis.

• 생물환경조절학회지
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• 제17권4호
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• pp.273-282
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• 2008

수분 공급을 제한하여 수분 부족 스트레스를 처리한 상추식물에서 산화적 스트레스와 관련된 monodehydroascorbate reductase (MDHAR)의 활성도, 엽록소 함량, 과산화수소의 함량 등과의 상관관계를 조사한 결과, 생육배지의 수분의 함량이 감소함에 따라 식물체내 과산화수소의 생성량이 증가($R^2$=0.8851)하였으며, 수용성단백질 함량은 점차 감소($R^2$=0.9826)하는 경향을 나타내었다. 총 엽록소함량은 수분 부족 스트레스를 처리한 공시작물에서의 함량이 정상 생육시 보다 그 함량이 대체적으로 낮은 경향을 보였으며, 엽록소 a와 엽록소 b함량 변화도 총 엽록소의 함량변화와 비슷한 경향을 보였다. 그러나 총 엽록소에 대한 카로티노이드의 비율은 수분 부족 스트레스를 처리한 식물에서 정상생육 시 보다 더 높은 경향을 보였다. 수분 부족 스트레스가 진행됨에 따라 아스코브산의 함량은 정상 생육 시 보다 더 높은 경향을 보였으나 환원형인 디하이드로아스코브산의 함량은 수분 부족 스트레스를 처리한 초기에 정상생육 시 보다 더 낮은 경향을 보였다. MDHAR의 활성도는 사이토졸(cytosolic) 분획과 엽록체(chloroplastic) 분획에서 공히 크게 증가하였으며 MDHAR의 mRNA 전사 정도도 수분 부족 스트레스가 진행됨에 따라 크게 증가하였다. 수분함량이 감소함에 따라 MDHAR의 활성도가 크게 증가하였으며, 또한 과산화수소의 함량이 증가함에 따라서도 MDHAR의 활성도가 크게 증가($R^2$=0.9937과 0.8645)되어 수분 부족 스트레스로 나타나는 요인들과 MDHAR 사이에 밀접한 관련이 있음을 확인할 수 있었다.

• 한국물환경학회지
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• 제22권6호
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• pp.1060-1067
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• 2006

Water quality in the Daecheong reservoir has been deteriorated by algal bloom due to nutrient supply from the upstream of the Daecheong reservoir after heavy rainfall. Algal bloom is propagated from eutrophicated tributary into the main body of the reservoir according to the hydrological conditions. This study is aimed to estimate the water current and temperature effect by the simulation of dam spill flow control using water quality model, CE-QUAL-W2 in 2003. Water current was resulted in nutrient transport from upstream of main reservoir and nutrients were delivered up to downstream by fast water velocity. Algal blooms occurred in stagnate zone of reservoir downstream as the current of downstream was retarded according to dam outflow control. Consequently water balance in stagnate zone triggered a rise of water temperature in summer. It affected algal bloom in the embayment of the reservoir. The simulation result by outflow control scenarios showed that spill flow augmentation induced in water body instability of stagnate zone so that water temperature declined. It could be suggested that outflow control minimize algal bloom in the downstream in the flooding season as long as water elevation level is maintained properly.

• 상하수도학회지
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• 제28권1호
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• pp.1-11
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• 2014

The water distribution system should be invariably operated on continuous pattern for 24 hours a day. Occasionally, it is not practically possible to operate for 24 hours due to water shortage or financial constraints. Therefore an intermittent water supply is unavoidable in water shortage area and developing countries. But the intermittent water supply can introduce large pressure forces and rapid fluid accelerations into a water supply network. These disturbances may result in new pipe failure, leakage and secondary contamination. This paper proposed an improvement methodology to prevent the disturbances by intermittent water supply. For the study, the hydraulic variation of intermittent flow in water distribution system was measured and analyzed in the field by comparing with simulation of hydraulic model. Installations of control valves such as, pressure reducing and sustaining and air valves were employed for pressure and flow control. The effectiveness of the methods are presented by comparing hydraulic conditions before and after introducing the proposed solutions.

• Coupled systems mechanics
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• 제11권1호
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• pp.79-91
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• 2022

Models for water treatment processes include simulation, i.e., modelling of water quality, flow hydraulics, process controls and design. Water treatment processes are inherently dynamic because of the large variations in the influent water flow rate, concentration and composition. Moreover, these variations are to a large extent not possible to control. Mathematical models and computer simulations are essential to describe, predict and control the complicated interactions of the water treatment processes. An accurate description of such systems can therefore result in highly complex models, which may not be very useful from a practical, operational point of view. The main objective is to combine knowledge of the process dynamics with mathematical methods for processes estimation and identification. Good modelling practice is way to obtain this objective and to improve water treatment processes(its understanding, design, control and performance- efficiency). By synthesize of existing knowledge and experience on good modelling practices and principles the aim is to help address the critical strategic gaps and weaknessesin water treatment models application.

• 대한물리치료과학회지
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• 제8권1호
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• pp.885-892
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• 2001

The purpose at this study was comparied at effect the pulmonary function to breathing exercise(BE) in water with on land. The result was as follow: FVC(Forced Vital Capacity) was decreased 1.5% in control group, increased 1.5% in BE on land group and increased 6.5% in water group after BE, but no significant difference in water group. FEV1(forced expiratory volume at one second) was increased 0.2% in the control group, decreased 0.7% in BE on land group and increased 5.7% in BE in water group after BE, but no significant difference in water group. MVV(maximal voluntary ventilation) was significant difference in BE in water group who was increased 12.2% after BE. It was decreased 1.0% in the control group and increased 0.2% in BE on land group. VC(vital capacity) was decreased 1.5% in the control group, increased 6.2% in BE on land group and increased in BE in water group after BE, but no significant difference in water group. IC(Inspiratory Capacity) was decreased 0.5% in the control group, increased 7.5% in BE on land group and decreased 2.0% in BE in water group after BE, but no significant difference on land group. ERV(Expiratory Reserve Volume) was decreased 0.5% in the control group, increased 3.0% in BE on land group and increased 8.5% in BE in water group after BE, but no significant difference in water group.

• 조명전기설비학회논문지
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• 제28권2호
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• pp.24-30
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• 2014

In this paper, a new remote terminal unit(hereafter RTU) is proposed to manage a wide range of applications and a variety of sensors (eg, pressure, water quality, temperature and humidity sensors, the amount of pollutants, $CO_2$, etc.) to monitor and control the facility such as water treatment plant, intake and effluent pumping station, water tank and distribution network. Fault status of local sensor devices and network are alerted by using the embedded fault handling capabilities of the RTU in the system and also sent to the fault handling server, by which fault can be easily monitored to users. The developed system was applied to one of K-water branch offices in Geoje city and improved its reliability and stability for controlling and monitoring water facility.

• 생명과학회지
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• 제9권4호
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• pp.368-374
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• 1999

Three soybean cultivars, Hwangkeum, Tanyeob and Enrei were planted in the same pot under glasshouse conditions to investigate the influence of the different soil water content such as pF 1.4(wet), 2.1(control) and 3.6(dry) on the transpiration rate, dry matter production and water requirement. The transpiration rate remained the high constant rates under the wet soil condition and the control than the dry condition, and showed a linear correlation between transpiration rate and solar radiation under the all condition of soil water. The transpiration rate highly increased in the morning, but dramatically decreased in the other time in a day. The dry matter production was higher under the conditions of wet soil and the control than that under the dry condition. Also, the dry matter production Tanyeob was higher than other cultivars under all soil water content. The water requirement was higher for Enrei and lower Tanyeob than the control.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.161-166
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• 2009

Condensing gas boiler units may make a big role for the reduction of energy consumption in heating industries. In order to decrease the energy consumption of a boiler unit, the effective operation is necessary. In this study, the supply water temperature algorithm of a condensing gas boiler was developed. This includes the setpoint algorithm and the control algorithm of the supply water temperature. The setpoint algorithm was developed by the fuzzy logic and the control algorithm was developed by the proportional integral algorithm. In order to analyse the performance of the supply water temperature algorithm, the dynamic model of a condensing gas boiler system was used. Simulation results showed that the supply water temperature algorithm developed for this study may be practically applied for the control of the condensing gas boiler.