• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.197-204
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• 1992

A comparative evaluation of water quality in the existing semiclosed fish culture system was made to improve the system management. From the comparison of water quality between the flow-through mode and the recycle mode of the semiclosed system, the malfunctioning of the settling channel deteriorated water quality and reduce the nitrification rate in the recycle mode. The peak concentrations of COD, $PO_4-P$ and SS in the fish tanks appeared just after feeding, and then decreased to normal levels within two hours. However, the $NH_4-N$ concentration increased slightly after two hours of feeding in the recycle mode. The water exchange rate was directly related to the water quality in the semiclosed fish culture system.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.59-70
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• 2022

In this paper, we proposed an active fault tolerant control (AFTC) method for the position control of a quadrotor with complete loss of effectiveness of one motor. We obtained the dynamics of a quadrotor using Lagrangian equation without small angle assumption. For detecting the fault on a motor, we designed a fault detection module, which consists of the fault detection and diagnosis (FDD) module and the fault detection and isolation (FDI) module. For the FDD module, we designed a nonlinear observer that observes the states of a quadrotor based on the obtained dynamics. Using the observed states of a quadrotor, we designed residual signals and set the appropriate threshold values of residual signals to detect the fault. Also, we designed an FDI module to identify the fault location using the designed additional conditions. To make a quadrotor track the desired path after detecting the fault of a motor, we designed a fault tolerant controller based on the multiple sliding surface control (MSSC) technique. Finally, through simulations, we verified the effectiveness of the proposed AFTC method for a quadrotor with complete loss of effectiveness of one motor.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.221-227
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• 2008

This paper is to show the designing for LED lights driver unit. The main purpose of driver designing is high electrical efficient performance and intelligent control LED driver. Nowadays, a lightning system with some of charactestics such as an environmentally friendly purposes with a possible reduction of electric power consumptions. We constitute a intelligent contron LED control system that helps to save an electric energy, and a communication system to control the system. This LED driver can be used for intelligent light control. This product expects to improve the light control by dimming instead of interlace on/off light control that increases the social cost such as car accidents and etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.744-747
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• 2010

This paper presents a novel adaptive control method for DC-DC converters applied in PV generator systems. We derive an state-space average model of the converter system and then propose a adaptive control methodology to enhance transient response performance for time-varying PV systems. A well-knwon Lyapunov theory is utilized for constructing our control algorithm. Numerical simulation demonstrates reliability of our control methodology and its superiority by comparison to a traditional control strategy.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.169-172
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• 2008

This paper is a report of designing for high efficient LED lights driver. The main purpose of driver designing is meet the requirement the high efficient energy regulation for light of Korea. To meet the regulation the high efficient, the circuit adapted wide range resonant power supply and current regulate circuit to adjust LED current. This product archived excellent performance as well as reliable operation.

• Proceedings of the KAIS Fall Conference
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• 2002.11a
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• pp.258-259
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• 2002

본 연구는 304 STS을 전해연마하여 표면의 조도를 나노 단위까지 제어하기 위한 leveller의 개발이 목적이다. 이를 위해서 AFM을 이용하여 조도를 측정하였고 분극실험을 통해 표면특성을 연구하였다. 전해연마는 인산:황산:증류수를 8:1:1 비율로 전해액을 만들었고 부가적으로 첨가제를 넣어 전해연마를 실행했다. 분극실험은 일정한 전극간격을 유지하여 정전압 조건에서 1mV/s의 속도로 주사하여 실험하였다. 전해연마 시간이 증가함에 따라, 첨가제의 양이 적게 들어갈수록 평활도가 향상됨을 볼 수 있었다.

• The Magazine for Energy Service Companies
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• s.23
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• pp.22-25
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• 2003

자동제어사업의 선두주자로 그동안 축적해온 기술과 노하우를 ESCO사업에 적극 적용하고 있는 한국하니웰은 해마다 사업실적 최상위권을 유지하며 에너지절약시장에서 맹위를 떨치고 있다. 이 회사는 부설연구소 뿐 아니라 국내외 유수의 에너지절약 관련 연구소와의 공동연구를 통해 연구결과를 사업에 적용, 지원하는 시스템을 채택하는 한편, 미국 하니웰사와 연계한 탄탄한 기술력을 바탕으로 에너지절약시설 제공 및 설치를 포함하는 턴키(Turn Key)방식의 ESCO사업을 적극 추진하고 있다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.107-108
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• 2015

본 논문의 목적은 먼지 감지 센서, 우적 센서, 조도 감지센서와 자동 장치를 창문에 부착하고 Arduino에 연결하여 외부 환경에 따라 자동으로 창문을 여닫도록 하는데 있다. 입사광의 산란 검출을 기반으로 하는 먼지센서, 비가 내리는 양에 따른 저항 값의 변화를 감지하는 우적센서, 빛의 밝기에 따라 저항 값이 바뀌는 조도 감지 센서를 제어용 컴퓨터인 아두이노에 연결하여 데이터를 입력 받도록 한다. 사용자의 설정에 따라 입력 받은 데이터를 이용하여 창문의 여닫음을 결정하고 이를 창문에 부착한 자동장치를 통해 능동적으로 구현한다. 본 연구를 통해 사용자의 편의성을 향상시킬 수 있으며 나아가 냉난방기 사용을 줄여 에너지를 절약하는 효과를 기대한다.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.83-94
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• 2012

Slopes are commonly formed both above and below roads located in mountainous terrain and along riversides. The Buk-sil site, a cut slope formed below the road, collapsed in October, 2010. A field investigation determined the causes of failure as improper drainage of valley water from the slope above the road and direct seepage of road-surface water. These factors may have accelerated the collapse via complex interaction between water and sub-surface structures such as bedding. Projection analysis of the site showed the possible involvement of plane, wedge, and toppling failure. Safety factors calculated by Limit Equilibrium Analysis for plane and wedge failure were below the standard for wet conditions. The wetness index, analyzed using topographic factors of the study area, was 9.0-10.5, which is high compared with the values calculated for nearby areas. This finding indicates a high concentration of water flow. We consider that water-flow control on the upper road is crucial for enhancing slope stability at the Buk-sil site.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.270-273
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• 2017

Productivity through reduced defects in plastic injection molding and reduced cycle times is a long-standing need in the injection industry. In particular, productivity is very urgent for the domestic injection industry, which is caught between the pursuit of latecomers such as China and technological gap with Germany and Japan which will not be narrowed down. Through 30 years of research and experience in the domestic injection industry, we have found that controlling the surface temperature of injection molds is the key of quality control. There have been various attempts to utilize advanced control techniques such as PID control, but the productivity against leading companies in Germany and Japan is still insufficient. Using Approximation Algorithm - "Knapsack" and "Minimum Makespan Scheduling", We want to show how to efficiently control objects with periodic repetitive data patterns that are difficult to solve with PID control. In addition, We want to propose that the control by Approximation Algorithm is effective enough to improve the productivity of the product by analyzing the data extracted from actual injection site.