• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권6호
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• pp.402-408
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• 2004

This paper proposes the novel V/f control method to improve the stability of a V/f controlled induction motor drive system. The conventional V/f control method used in the proposed V/f control method is a vector-based method that is slightly different from the existing conventional V/f control method. The proposed control method uses a dynamic current compensator to improve the stability of a V/f controlled induction motor drive system. This proposed method is easy to implement and completely eliminates the motor oscillation phenomenon causing the instability of a V/f controlled induction motor drive system, especially when the system is driven near the resonant frequency in steady-state with light load. Additionally, this paper analyzes theoretically the instability of a V/f controlled induction motor drive system and shows the validity of the Proposed V/f control method through simulation and experimental results.

• International Journal of Safety
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• 제3권1호
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• pp.38-46
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• 2004

This paper introduces the software life-cycle V&V (verification and validation) tasks for the KNICS (Korea nuclear instrumentation and control system) project. The objectives of the V&V tasks are mainly to develop a programmable logic controller (PLC) for safety critical instrumentation and control (I&C) systems, and then to apply the PLC to developing the prototype of an engineered safety features-component control system (ESF-CCS) in nuclear power plants. As preparative works for the software V&V, various kinds of software plans and V&V task procedures have been developed according to the software life-cycle management. A number of software V&V tools have been adopted or developed to efficiently support the V&V tasks. The V&V techniques employed in this work include a checklist-based review and inspection, a requirement traceability analysis, formal verification, and life-cycle based software testing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.218-222
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• 1987

The continuously variable transmission (C.V.T.) has been introduced for many years, however, the application of C.V.T. system has been used rather restrictively because of the problems such as reliability, durability, efficiency and, controllability. In this paper, some of the research trends about the control algorithms and the system design method involving C.V.T. is introduced. An engine is assumed in operation along the ideal operating line and it is also considered to be controlled independently to the C.V.T. system. The control simulation has been carried out to confirm it and also the operation performance of the system is investigated.

• Journal of information and communication convergence engineering
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• 제19권4호
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• pp.214-220
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• 2021

In this study, we constructed several scenarios that are required for LED lighting, and we designed and implemented an LED lighting control system to operate these scenarios to confirm their behavior. An LED lighting control system is a hybrid control board that is designed by combining LED controllers and SMPS, consisting of an AC/DC power supply part that converts AC 220 V into DC 12 V, and a drive and control part that controls the scenario and color of the LED module. Conventional LED light controllers have an input power of DC 12 V, so when using the input AC 220 V, the SMPS must be connected to the LED light controller. To eliminate this inconvenience, a hybrid LED lighting control system was configured to combine LED lighting controllers and SMPS into one control system. Furthermore, we designed a control system to represent the most appropriate color according to the input of the distance and illumination using a fuzzy control system to conduct computer simulations.

• 스마트미디어저널
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• 제12권5호
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• pp.73-80
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• 2023

최근 지능형 관제 시스템은 다양한 응용 분야에서 빠르게 발전하고 있으며, 딥러닝, IoT, 클라우드 컴퓨팅 등의 기술이 지능형 관제 시스템에 활용하는 방안이 연구되고 있다. 지능형 관제 시스템에서 중요한 기술은 영상에서 객체를 인식하고 추적하는 것이다. 그러나 기존의 다중 객체 추적 기술은 정확도 및 속도에서 문제점을 가지고 있다. 본 논문에서는 객체 추적의 정확성을 높이고, 객체가 서로 겹쳐있거나 동일한 클래스에 속하는 객체들이 많을 경우에도 빠르고 정확하게 추적 가능한 원샷 아키텍처 기반의 YOLO v5와 YOLO v6을 사용하여 실시간 지능형 관제시스템을 구현하였다. 실험은 YOLO v5와 YOLO v6를 비교하여 평가하였다. 실험결과 YOLO v6 모델이 지능형 관제시스템에 적합한 성능을 보여주고 있다. 실험결과 YOLO v6 모델이 지능형 관제시스템에 적합한 성능을 보여주고 있다.

• Journal of Mechanical Science and Technology
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• 제15권1호
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• pp.66-80
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• 2001

In brake systems, a proportioning valve(P. V), which reduces the brake line pressure on each wheel cylinder for the anti-locking of rear wheels, is closely related to the safety of vehicles. However, it is impossible for current P. V. s to completely control brake line pressure because, mechanically, it is an open loop control system. In this paper we describe an electronic brake force distribution system using a direct adaptive fuzzy controller in order to completely control brake line pressure using a closed loop control system. The objective of the electronic brake force distribution system is to change the cut-in-pressure and the valve slop of the P. V in order to obtain better performance of the brake system than with mechanical systems.

• 한국추진공학회지
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• 제19권2호
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• pp.73-80
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• 2015

Apollo Mission이 종료된지 거의 반세기가 지났지만, 지금도 Saturn V 발사체의 기술의 복원과 개량을 위한 연구가 활발하게 진행되고 있다. 본 연구에서는 Saturn V 발사체의 1단 로켓(S-IC)의 개발 과정과 엔진 퍼지, 포고현상 억제 방법, 연료탱크 가압 방식, 유압 및 공압 시스템의 운용 방식 등에 대한 특징들에 대해 조사하였다. S-IC의 추진기관 시스템의 특징에 대한 이해는 발사체 시스템의 이해를 도울 수 있고, 향후 발사체 개발 시에 시간, 비용 등의 절감 효과를 가져다 줄 수 있는 유용한 참고 자료가 될 것이라 예상된다.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1999년도 PROCEEDINGS OF 99 INTERNATIONAL CONFERENCE OF THE KACG AND 6TH KOREA·JAPAN EMG SYMPOSIUM (ELECTRONIC MATERIALS GROWTH SYMPOSIUM), HANYANG UNIVERSITY, SEOUL, 06월 09일 JUNE 1999
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• pp.361-369
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• 1999

New method of control based upon a physical model of the Stepanov growth technique has been developed. The controller keeps the system stable and completely denies operator's interference into the process. The system demonstrates very reliable results under commercial production of shaped sapphire crystals.

• 한국결정성장학회지
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• 제9권4호
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• pp.437-440
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• 1999

New method of control based upon a physical model of the Stepanov growth technique has been developed. The controller keeps the system stable and completely denies operator's interference into the process. The system demonstrates very reliable results under commercial production of shaped sapphire crystals.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.466-469
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• 2001

In this paper, closed loop V/f control of induction motor has been implemented by the estimated speed. Closed loop V/f control improve the performance of induction motor drive system at low speed compared to open loop V/f control. However, closed loop V/f control need speed sensor. By using the estimated speed, closed loop V/f control is possible without speed sensor. Rotor speed is calculated from the difference between synchronous frequency and slip angular frequency. 3-phase voltage reference is obtained from synchronous frequency. And the PWM technique using space vector PWM is applied in this scheme. In the space vector PWM, effective time of 3-phase voltage reference is used to simplify the calculation of effective voltage time. This scheme is simple to implement and one chip microprocessor was used in experimental system.