• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.164-168
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• 1986

This paper describes an overview of the remote Supervisory Control And Data Acquisition (SCADA) System for automatic operation of Electric power system in KEPCO. And the example of improvement and development for effective operation of the SCADA is reported briefly.

• Speech Sciences
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• v.1
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• pp.237-259
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• 1997

Cleft Palate speech appears to have hyper/hyponasality with velopharyngeal insufficiency and articulation disorders. Previous studies on Cleft Palate speech have shown that speech tends to have lower airflow and air pressure. To examine the aerodynamic characteristics of Cleft Palate speech, Aerophone II Voice function Analyzer was used. We measured sound pressure level, airflow, air pressure and glottal power. Three Cleft Palate adults and five normal adults participated in this experiment. The test words are composed of: (1) the sustained vowel /o/ (2) /CiCi/, where C is one of three different stop consonants in Korean (3) /bimi/. Subjects were asked to produce /bimi/ five times without opening their lips. All the data was statistically tested by t-test for Cleft Palate patients before operation groups and control groups and paired t-test for Cleft Palate patients before and after operation groups. The results were as follow: (1) Cleft Palate patients generally speak with incomplete oral closure and lower oral air pressure. As a result, the SPL of Cleft Palate before operation is 3 dB lower than control groups. (2) Airflow of Cleft Palate in phonation and articulation is lower than that of control groups. However, it increased after operation. Lung volume and mean airflow in phonation are significantly increased (p<0.05). (3) Although velopharyngeal function (velar opening rate) of Cleft Palate is poor in comparison with control groups, it was recovered after operation. In this event maximum flow rate and mean airflow rate are significantly increased (p<0.05). (4) Air pressure of Cleft Palate in speech is lower than that of control groups. In general, the air pressure of Cleft Palate increased after operation. In this event air pressure of glottalized consonant is significantly increased (p<0.04). (5) Glottal Power(mean power, mean efficient and mean resistant) of Cleft Palate patients is lower than that of control groups. But mean efficient and mean resistant of Cleft Palate patients increased significantly (p<0.05) after operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1496-1501
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• 2012

A fine tuning on a control system is essential not only for stable operation but also for efficient operation of the power plant. There has been a very few studies on efficiency change by control system tuning. So, it was not clear that if it could be improved or not when the control is stable by fine tuning and how much it could be improved if it works. An accurate algorithm for measurement of the plant efficiency was newly introduced and implemented to measure integrated fuel flow and electricity MW output and to calculate the mean efficiency for given time. As a result, stable operation after fine tuning of control parameters for major controlled variables brought higher efficiency than un-stable operations like a cycling or an oscillation. The plant efficiency has been monitored during various tests and tunings to confirm how much it changes by tuning of the control system on power plant. Now, we can say that the efficiency can be improved in stable operation by fine tuning of the control system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2300-2305
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• 2011

A Train control system is intended to assure train operation safety and to improve train operation efficiency. To perform these missions, the Train Control System consists of train safety space control part, train route control part and train operation management part. Train control technology changed from track circuit based to wireless based. And Wireless based train control technologies were developed by some railway signaling companies in Korea. To commercialize these control technologies, the development project is carried now. This project did analyze system requirements, and made the system development specification. Now this project finished system functions allocation, which will be performed by some subsystem. This paper describes roles of each function and the allocation of these functions to each subsystem.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.212-217
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• 2020

We studied on the design of a sprinkler control system that communicates with the administrator's mobile through a wireless communication network and a sprinkler unit that sprays water on the vegetation area. This sprinkler control system consists of a communication module that receives an operation signal for the operation of the sprinkler unit from the administrator's mobile, and a control module that controls the sprinkler unit according to the operation signal received through the communication module. It is also designed to control sprinkler units by measuring temperature, humidity, light intensities, vibration and field images in the vegetation area in real time through sensors and camera for each of them and comparing them with established limit criteria. The sprinkler allows the administrator to control the sprinkler more easily because the administrator operates the sprinkler through the mobile from a distance, and emergency situations occur and can respond quickly.

• International Journal of Automotive Technology
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• v.5 no.3
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• pp.201-208
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• 2004

Response characteristics of the CVT system for a parallel hybrid electric vehicle (HEV) are investigated. From the experiment, CVT ratio control algorithm for the optimal engine operation is obtained. To investigate the effect of the CVT system dynamic characteristics on the HEV performance, a hardware in the loop simulation (HILS) is performed. In the HILS, hardwares of the CVT belt-pulley and hydraulic control valves are used. It is found that the engine performance by the open loop CVT ratio control shows some deviation from the OOL in spite of the RCVs open loop control ability. To improve the engine performance, a closed loop control of the CVT ratio is proposed with variable control gains depending on the shift direction and the CVT speed ratio range by considering the nonlinear characteristics of the RCV and CVT belt-pulley dynamics. The HILS results show that the engine performance is improved by the closed loop control showing the operation trajectory close to the OOL.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.433-438
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• 2012

In this paper, a operation network system equipped with onboard wireless communication systems and ground-based mission control systems is proposed for swarm flight of small UAVs. This operating system can be divided into two networks, UAV communication network and ground control system. The UAV communication network is intend to exchange the informations of navigation, mission and flight status with minimum time delay. The ground control system consisted of mission control systems and UDP network. Proposed operation network system can make a swarm flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperte several missions. Finally, PILS environments are developed based on the total operating system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.545-551
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• 1997

As the cooling energy requirement in an office building increases due to the increased internal heat gains, the effort to minimize the energy consumption through efficient operation of existing HVAC systems will be beneficial. In this study, one of the energy conserving efforts in an office building, operational strategies of Economizer Cycle Control have been investigated through DOE-2.1E computer simulation. The findings can be summarized : 1) Economizer Cycle Control saves energy throughout the year, 2) Econo-Limit-T must be applied seasonally based on the outside and return air conditions, 3) use of Enthalpy control is more energy efficient than that of Temperature control.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.217-225
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• 2005

Because of the limitation of controllable operation variables for the wastewater treatment process with variable hydrodynamic flow patterns, it may preclude the use of this type of nutrient removal activated sludge process. As the operation variables, only temperature and dissolved oxygen (DO) have been used to operate the process. This study made an effort to improve treatment efficiency and operability of the process by the following methodologies: 1) process and operation data analysis using process simulation, 2) determination of optimal control logic or algorithm using a pilot-scaled experimental apparatus and its operations, and 3) application of experimental and simulation results to find the optimal process operation modes. In this study, it was found that the optimal operation mode named 'save mode' in the basis of process variables, such as the ammonia-nitrogen concentration of inlet flow, temperature and flow rate, can reduce the operation cost comparing with the present normal operation mode. And the stable conditions in nitrification were also shown by the proportional control of DO with the inlet air flow rate of blower and the mixing rate of mechanical aeration.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.85-86
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• 2013

This paper describes the physical configuration and features of the advanced control and protection devices, and operation control and monitoring system that are connected to a real time simulator for LS Industrial System 80kV 60 MW Jeju HVDC Pilot Project. Highlight of simulation result are provided to demonstrate the control and protection functionality.