• 한국미생물·생명공학회지
• /
• 제28권5호
• /
• pp.285-290
• /
• 2000

The effects of dissolved oxy-gen(DO) concentration and DO control modes on cell growth in a 4L computer-controlled bioreactor system were investigated using Phellinus linteus WI-001, a producer of protein-polysaccharides having potent anticancer activi-ties. When DO was controlled at about 20%, maximum cell concentration and specific growth rate of the strain were observed to increase 36% and 64%, respectively, as compared to the experiment performed without DO control. By adopting cascade automatic control of DO ar 20% in a mixed automatic control mode using computer-con-trolled program, 19.5g/L of maximum cell concentration was obtained. These results showed that the mixed auto-matic control mode was the effective method for enhancing cell growth of the shear sensitive Phellinus linteus.

• 한국환경과학회지
• /
• 제8권4호
• /
• pp.533-538
• /
• 1999

Fuzzy algorithm of automatic control for dissolved oxygen(DO) concentration in the aeration tank of an activated sludge process is proposed. Among variables repirometry and air flowrate are selected as significant input factors and the relationship with DO is estimated using a multiple regression model. The DO concentration and the amount of repirometry are fuzzified and the fuzzy rule base are determined. Using the fuzzy algorithm, the change of amount of air flowrate are determined and the change of amount of DO is derived.

• 한국환경과학회지
• /
• 제18권6호
• /
• pp.603-608
• /
• 2009

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.

• 생태와환경
• /
• 제43권2호
• /
• pp.338-344
• /
• 2010

상수원 및 수계의 수질관리 업무를 효율적이고 능동적으로 수행하고, 수질오염사고 발생시 신속한 대응조치를 할 수 있는 조기경보체계 구축을 위하여 주요 상수원 및 하천 등에 수질자동측정망을 설치하여 운영하고 있다. 수온, pH, EC, DO, TOC 항목에 대한 정도평가를 실시하여, 수질자동 측정 자료에 대한 정확도를 확보하여 신뢰도를 제고하고자 하였다. 수질자동측정기기와 수동측정기기에 대한 측정값을 비교한 결과, 대체로 일반항목(수온, pH, EC, DO) 및 TOC의 상대정확도가 20% 이내의 목표를 만족하였다. 그러나 수질자동측정소의 저류수조의 측정기기(내부)와 채수지점의 측정기기(외부)의 측정값 차이를 분석한 결과, 채수거리가 먼 측정소의 DO에 대한 내부-외부의 상대정확도는 목표값을 다소 벗어나는 것으로 나타났다. 채수관로에 조류 및 미생물 부착에 의한 오염이 원인으로 판단되어 역세척하여 측정한 결과, 측정된 DO 농도는 최대 53%까지 상승하는 효과를 나타냈다. 따라서 채수관로 관리가 수질자동측정 자료의 신뢰성을 확보하는데 중요함을 알 수 있었다.

• 한국환경보건학회:학술대회논문집
• /
• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
• /
• pp.147-149
• /
• 2003

Automatic monitoring and controling system, especially DO and MLSS was faciliated for the nitrogen and phosphorus removal efficiencies. Removal efficiency of nitrogen and phosphorus by automatic monitoring and controling system, especially DO and SRT was have well adopted. and so it will be possible to use artificial intelligence logic control software such as fuzzy or neuro logic control system for WWT Plant.

• 대한기계학회논문집A
• /
• 제26권5호
• /
• pp.822-827
• /
• 2002

In general, jerk phenomenon appeared because of gear changing, when a vehicle starts off or climbs an incline. Therefore, it makes ride quality worse. In this paper, an optimal pattern of automatic transmission was designed using fuzzy logic in order to improve ride quality. After del eloping fuzzy rule for shift pattern control of automatic transmission, dynamic characteristics (i.e. acceleration, velocity, distance and so on) were simulated using dynamic model of a car. To do this he powertrain model of a vehicle with automatic transmission including torque converter, gear box, and final gear drive - from engine to tire - is developed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.505-508
• /
• 1995

This paper suggests new hydraulic circuit to control the pressure of clutches and brakes which has several advantages than conventional hydraulic circuit in automatic transmissions. In conventional hydraulic circuit, the pressures of all friction elements are controlled by only one pressure control valve and accumlators. So, controllable range is limited and it is unable to control the friction elements independently. Therefore, we can not do the fine control of timing between apply clutch and release clutch which is needed in clutch-to clutch shifting automatic transmissions. To overcome these faults, we designed the direct-acting hydraulic circuit where one pressure control valve and pressure control solenoid valve are allocated to each friction element and control that independently. Through this structural improvement of hydraulic circuit, we can achieve elaborate aontrol to clutch pressure. Specially, We can control the timing between apply clutch and release clutch delicately which is needed in clutch-to-clutch shifting.

• Journal of Biosystems Engineering
• /
• 제20권4호
• /
• pp.383-389
• /
• 1995

This study was conducted to develop an automatic nutrient control system for trickle application of nutrient solution. Temperature, electric conductivity(EC). pH and dissolved oxygen(DO) were selected as control variables. A controller using single-chip microcomputer was constructed. An automatic control system for nutrient solution and a controller using single-chip microcomputer with control algorithm were developed. The control system was tested, and could control temperature, EC and pH within the error ranges of $pm 0.2^{circ} pm 0.2mS/cm, pm 0.1pH$, respectively.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1396-1399
• /
• 1996

With the progress in process automation, it becomes necessary that a robot should have various sophisticated capabilities. A robot programming language is a tool that can give a robot such capabilities without any change in robot architecture. Especially a task level automatic programming system enables a robot able to perform a job intelligently. Therefore anyone who is not an expert on welding or robot programming can easily use it. In this research, basic automatic welding program is combined with workspace information, which makes users do an arc welding job automatically.

• 한국정밀공학회지
• /
• 제18권9호
• /
• pp.53-60
• /
• 2001

This paper presents a position control of a platform at the seaport cargo handling system. After brief description of the operating principles of the cargo handling system, the governing equation of the moving platform is derived. The equation is described in the state space model, and a robust H$_{\infty}$ controller to achieve position tracking of the moving platform. which can carry 200ton of containers, is formulated. In the synthesis of the controller, the weight of the container is treated as uncertain parameter. Both regulating and tracking control responses are analyzed for the loading and unloading procedures of the proposed automatic cargo handling system.