• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 춘계학술대회 및 임시총회
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• pp.203-206
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• 2002

This paper describes fuzzy control methodologies of the steam generator which have nonlinear characteristics in the nuclear power plant. Actually, the steam generator part of the power generator has a problem to control water level because it has complex components and nonlinear characteristics. In order to control nonlinear terms of the model, Takagj-Sugeno (75) fuzzy system is used to design a controller. In designing procedure, intelligent digital redesign method is used to control the nonlinear system. This digital controller keeps the performance of the analog controller. Simulation examples are included for ensuring the proposed control method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.172-174
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• 1995

About a half of Electric power is generated by nuclear power plants in korea. So, the stable operation of nuclear power plant is very important for suppling the essential national electric power. A S/G(Steam Generator) level control is the most difficult system in PWR(Pressurized Water Reactor) nuclear power plant. Because of the non-linear and the non-nominal response of S/G level control, it Is very difficult to control the level by automatic mode or manual mode. The goal of this study is to establish and verify a advanced control algorithm by analyzing, modelling, stability calculation, controller parameter calculation, simulation for S/G level control system.

• 동의생리병리학회지
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• 제22권1호
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• pp.89-95
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• 2008

This experimental study was designed to investigate the effects of Ijin-tang add Atractylodis rhizoma and Atratcylodis macrocephalae rhizoma (IJTAA) on the change of weight and serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, free fatty acid, total lipid and phospholipid level in obese mice induced by high fat diet. Experimental groups were as follows ; Normal group was fed normal diet and administered distilled water during 7 weeks, Control group was fed high fat diet and administered distilled water during 7 weeks, Sample A group was fed high fat diet and administered IJTAA 500 ㎎/㎏/day/mouse during 7 weeks, Sample B group was fed high fat diet and administered IJTAA 700 ㎎/㎏/day/mouse during 7 weeks. The results were as follows ; 1. In Sample A group and Sample B group, There were significantly decreased in body weight, serum total cholesterol level, serum triglyceride level, serum free fatty acid level, serum total lipid level and serum phospholipid level in comparison with Control group. 2. In Sample A group and Sample B group, There were significantly increased in serum HDL-cholesterol level in comparison with Control group. 3. In Sample A group and Sample B group, There were decreased in serum LDL-cholesterol level in comparison with Control group. According to above results, I suggest IJTAA is able to be used for managing obesity by controllong body weight, serum total cholesterol level, serum triglyceride level, serum free fatty acid level, serum total lipid level and serum phospholipid level.

• 한국작물학회지
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• 제48권3호
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• pp.238-242
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• 2003

본 연구는 간척지 토양 염농도별(저염; 0.1-0.2%, 중염; 0.3~0.4%)로 분얼기 관개수 염수처리 농도에 따른 벼 생육 및 수량성을 검토하고자 시험한 결과를 요약하면 다음과 같다. 가. 토양 및 관개수 염농도가 높을수록 초장은 짧았고 주당경수도 적었으며, 특히 중염 토양에서 관개수 염농도 0.3% 이상에서는 모두 고사되었다. 나. 토양 및 관개수 염농도가 높을수록 출수는 지연되었으며, 토양 염농도간에는 중염 토양에서 저염 토양보다 2-5일 정도 늦었다. 다. 간장은 관개수 염농도가 높을수록 짧았고 중염 토양이 저염 토양보다 짧았으며. 수장도 같은 경향이었다. 라. 저염토양에서는 관개수 염농도가 높을수록 $\textrm{m}^2$ 당립수가 적고 등숙비율이 낮아, 쌀수량은 민물 관개 수량에 비해 관개수 0.l%는 92%, 0.3%는 84%, 0.5%는 56%, 0.7%는 36% 수준이었다. 중염토양의 쌀수량은 저염토양 민물 관개 수량에 비해 민물 관개는 62%, 0.1% 관개수에서는 30% 수준이었다. 따라서 관개수 염농도가 저염 토양은 0.7%, 중염 토양은 0.3%까지 생육은 가능하나 수량 감소가 커서, 소득지수로 볼때 간척지 쌀 생산 한계 관개수 염농도는 저염 토양은 0.5% 이하에서, 중염 토양은 민물 관개수에서 가능하였다.

• 한국수자원학회논문집
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• 제46권11호
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• pp.1069-1078
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• 2013

울산시의 주요 생활용수공급댐인 사연댐 상류 수몰지역 내에 국보 285호인 반구대 암각화가 위치하고 있다. 표고 53~57 m에 위치한 암각화 보존을 위한 여러 가지 방안 중, 사연댐 수위를 60 m에서 52 m로 낮추어 물 밖으로 끄집어내는 안이 주로 검토되어 왔다. 댐의 수위를 인위적으로 조절하는 경우 저수량 및 용수공급량 감소와 더불어 부영양화로 인해 수질이 나빠지게 된다. 본 연구에서는 사연댐 수위조절에 따른 수질악화로 댐의 기능상실과 수질변화로 인해 예상되는 여러 가지 문제점을 검토하였다. Vollenweider 모델과 CSTR (Continuous Stirred Tank Reactor) 모델을 이용하여 수위조절시 변화가 예측되는 대표적인 수질지표인 BOD 및 COD 그리고 조류성장의 주 원인이 되는 총인과 총질소의 농도변화를 분석하였다. 그 결과 사연댐의 수위를 60 m에서 52 m로 조절하는 경우, COD의 농도는 약간 낮아지지만 총질소와 총인은 약 130% 이상 농도가 증가되는 것으로 나타났다. 이러한 변화는 심각한 조류문제를 일으킬 수 있으며, 사연댐의 수질관리를 영양염류의 농도를 대상으로 하는 경우 수질이 악화되는 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.460-467
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• 2010

In this study, the parameters of the feedwater control system (FWCS) of the OPR1000 type nuclear power plant (NPP) are optimized by response surface methodology (RSM) in order to acquire better level control performance from the FWCS. The objective of the optimization is to minimize the steam generator (SG) water level deviation from the reference level during transients. The objective functions for this optimization are relationships between the SG level deviation and the parameters of the FWCS. However, in this case of FWCS parameter optimization, the objective functions are not available in the form of analytic equations and the responses (the SG level at plant transients) to inputs (FWCS parameters) can be evaluated by computer simulations only. Classical optimization methods cannot be used because the objective function value cannot be calculated directely. Therefore, the simulation optimization methodology is used and the RSM is adopted as the simulation optimization algorithm. Objective functions are evaluated with several typical transients in NPPs using a system simulation computer code that has been utilized for the system performance analysis of actual NPPs. The results show that the optimized parameters have better SG level control performance. The degree of the SG level deviation from the reference level during transients is minimized and consequently the control performance of the FWCS is remarkably improved.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.299-304
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• 1998

Flood control of the Mekong delta should be developed over time for rural as well as urban areas. The hydraulic modelling effort is aimed an investigating flow distribution and water level. For the flood control study the flood model made with the VRSAP program is used. Concerning future improvement of the models it is recommended to improve the quality of water level and discharge, extend the number of the measuring locations needed for input for the models, systematically review and analyze future measurement campaigns in order to obtain better understanding of the complex hydraulic aspects, verify and update the topographical data used to model the rivers and cannals, carry out detailed calibration and verification of the models on water levels, discharges etc.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.659-669
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• 2004

The aim of this study was to evaluate the clinical efficacy of mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ on the control of gingivitis and incipient periodontitis when it was used as a adjunctives to the mechanical plaque control. 40 healthy patients with gingivitis or incipient periodontitis were divided into two groups. Patients in the experimental group use mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ after tooth brushing while patients in the control group do only tooth brushing for plaque control. All patients received scaling and tooth brushing instruction. 1 week after scaling was set as baseline. Probing pocket depth, clinical attachment level, and bleeding on probing were scored at baseline, 4 weeks. Gingival index and plaque index were scored at baseline, 2 weeks, and 4 weeks. The results were as follows: 1. In the experimental group, gingival index, plaque index, probing pocket depth, and clinical attachment level showed statistically significant decrease, but in the control group, significant increase(p<0.05). 2. There was no significant difference between the experimental and the control group in bleeding on probing, but significant decrease in the experimental group and Significant increase in the control group In a time-dependent manner(p <0.05). From these results, it can be concluded that regular use of mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ as adjunctives of mechanical plaque control, may be effective to prevent and treat gingivitis and incipient periodontitis.

• 전기학회논문지P
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• 제63권2호
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• pp.113-118
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• 2014

Tidal power is one of new and renewable energy sources. Tidal power is generated by using the gap in the water level between the water outside and inside the embankment. All tidal power plant in Korea were being operated by import of turn-key from abroad. The know-how and technology which are the most important to build predictive control system has become increasingly difficult to obtain from advanced countries because most of them avoid to transfer, which the domestic development of the control system is needed. In this paper, a study on start stop system at water turbine-generator for tidal power plant at the beginning of development was presented. For improvement the efficiency and develope of core technology of the start stop system, the technique and characteristics of tidal power, modeling, maximum generation calculation method, and optimal control of joint control system in Sihwa tidal power plant were studied.

• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.197-205
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• 2024

This paper presents a fully automated stand-alone irrigation system with GSM (Global System for Mobile Communication) module. Solar energy is utilized to power the system and it is aimed to conserve water by reducing water losses. The system is based on a DC water pump that draws energy from solar panels along with automated water flow control using a moisture sensor. It is also fitted with alert and protection system that consists of an ultrasonic sensor and GSM messages sender that transmits signals showing the levels of the water in the reservoir and the battery charge. The control system is designed to stop the water pump from pumping water either when the battery level drops to equal or less than 10% of its full charge, or when the water level becomes less than 10 cm high in the reservoir. The experimental results revealed that the system is appropriate to use in remote areas with water scarcity and away from the national grid.