• Journal of Korean Society on Water Environment
• /
• v.28 no.2
• /
• pp.300-304
• /
• 2012

It has a limitation to satisfy the phosphorus effluent criteria of 0.2 mg/L which will be reinforced from 2012 with the Biological Nutrient Removal (BNR) process. The chemical coagulation process has been operated in parallel with the biological treatment process for advanced treatment of phosphorous in the developed countries including Europe. However, the coagulation process has some disadvantages such as the desired goal may not be achieved without injecting the optimum dosage of the coagulant. This study developed the automatic control system to inject the optimum dosage of phosphorous coagulant into the coagulation process. The adopted coagulant was 10% Poly Aluminum Chloride (PAC) in this study. The automatic control system developed in this study was adopted for the treatment of the phosphorus from the effluent in SBR process. The automatic control system was composed of the data receiving part, the optimum coagulant dosage control part and the data transmit part. The result of the phosphorous advanced treatment of the SBR effluent using the automatic control system showed the removing efficiency over 95% consistently with the phosphorous concentration under 0.02 ~ 0.15 mg/L. The reproducibility analysis for checking the safety of automatic control system showed more than 95% correlation.

• Journal of Environmental Science International
• /
• v.18 no.6
• /
• 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.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2003.06a
• /
• 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.

• Journal of Environmental Science International
• /
• v.21 no.3
• /
• pp.383-390
• /
• 2012

For the cost-effective biological nitrogen removal (BNR) process whose characteristics of influent have low COD/N ratios, the automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in an anoxic reactor has been developed. In this study, it was carried out with a pilot-scale Bardenpho process which was consisted of anoxic 1, aerobic 1, aerobic 2, anoxic 2, aerobic 3 tank and clarifier. Firstly, the correlation coefficient ($R^2$) of the dosage of external carbon source and ORP value was about 0.97. Consequently, the automatic control system using ORP showed that the dosage of external carbon source was decreased by about 20% compared with a stable dosage of 75 mg/L based on the COD/N ratio of the anoxic influent.

• Journal of Environmental Science International
• /
• v.8 no.4
• /
• 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.

• Journal of Advanced Research in Ocean Engineering
• /
• v.2 no.4
• /
• pp.192-201
• /
• 2016

This study examined a PD controller and its application to automatic berthing control of an unmanned surface vehicle (USV). First, a nonlinear mathematical model was established for the maneuvering of the USV in the presence of environmental forces. A PD control algorithm was then applied to control the rudder and propeller during an automatic berthing process. The algorithm consisted of two parts, namely the forward velocity control and heading angle control. The control algorithm was designed based on longitudinal and yaw dynamic models of the USV. The desired heading angle was obtained using the "line of sight" method. Finally, computer simulations of automatic USV berthing were performed to verify the proposed controller subjected to the influence of disturbance forces. The results of the simulation revealed a good performance of the developed berthing control system.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.2
• /
• pp.311-315
• /
• 2012

Diaphragm type noncontact automatic control valve is a valve for controling acidic PR(Photo Resist) liquid used in the semiconductor process. PR is photosensitive liquid that changes phases depending on light transmittance. PR is very toxic and expensive; the purpose of this paper is to address methods that prevent loss due to leaks. The design of noncontact precise automatic control valve is expected to play an important role in controlling fluid flow, therefore influencing energy conservation and environmental improvement. In this paper, diaphragm type automatic control valve's part design, assembly and simulation are introduced. Also, through the analysis of fluid flow the valve's internal velocity, pressure, and turbulent intensity are interpreted. This paper proposes to contribute to the improvement of the valve's performance.

• Journal of Agricultural Extension & Community Development
• /
• v.11 no.1
• /
• pp.191-207
• /
• 2004

This study was focused on the development of greenhouse management and environmental control system using internet. The essence of this system were remote automatic control unit connected with greenhouse environmental control according to the growth stages of crops, The specific objectives of the study were; 1) to analyze need of greenhouse environmental remote control system, 2) to investigate the important functions related to greenhouse management program, 3) to explore the possibility of diffusing the system using internet.The study was carried out through review of related literature and need assessment from the research and extension workers in charge of greenhouse management using questionnaire survey, interview and field study. The results of the study were summarized as fallows: 1) About 89% of respondents responded positively on the need to establish automatic control system using internet. 2) The greenhouse management and environmental control system using internet was possible to control the greenhouse in remote, automatic, and simultaneous manner, and additionally by cellular phone in emergent situation. 3) The system was possible to precisely control the greenhouse environment, and it was able to connect the environmental control data with information on growth of crops. 4) By networking the farmer, extension educator of agricultural technology center and researcher, web based farm consulting was possible through the system. Based on the results of the study recommendations were suggested as follows: 1) Thorough spot inspections and field trials should be performed before the diffusion of this system. 2) The costs of the system installation and maintenance should be moderate. 3) The operation of the system should be simple and easy for tamers to adopt. 4) National support should be made to build better internet infrastructure in rural areas.

• Korean Journal of Agricultural Science
• /
• v.41 no.3
• /
• pp.251-258
• /
• 2014

In order to set up the basic environmental control systems which the new concept greenhouses have to equip, greenhouse characteristics, environmental management and control systems in domestic glasshouses and plastic houses were investigated and analyzed comparatively. Survey results on the width, length, eaves height, and the number of spans etc. showed that glasshouses were bigger than plastic houses significantly. New concept greenhouses claim to be plastic houses, but it will be reasonable to follow the specifications of the glasshouse. Specifications to be applied to new concept greenhouses were proposed as follows; hot water heating systems, aluminum screens as the thermal curtain, evaporative cooling systems, roof vents on the ridge, circulation fans, $CO_2$ enrichment, hydroponic systems, and automatic irrigation control systems. Environmental measurement systems for the indoor and outdoor temperature, humidity, light, wind speed and indoor $CO_2$ concentration have to be fully equipped. The automatic control system has to be as a complex environmental control system, not a single item control system. Also, for stable dissemination, domestically producing complete greenhouse control system should be made as soon as possible.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.43.4-43
• /
• 2001

This paper deals with motion identification using artificial neural network (ANN) and its application to automatic ship berthing. As ship motions are expressed by multi-term non-linear model, it is very difficult to find optimal methods for automatic ship berthing especially under environmental disturbances. In this paper, metier identification was used to estimate the effect of environmental disturbances and then the differences between values of identification and state variables are used to estimate the effect of environmental disturbances. A rule based-algorithm using the difference is suggested to cope with the effect of the disturbances. The algorithm adjusts the value of input units of ANN, which control a ship to keep desired route ...