• 디지털콘텐츠학회 논문지
• /
• 제3권2호
• /
• pp.245-254
• /
• 2002

현재, 자동화 시스템을 위한 통신분야는 TCP/IP를 기반으로 하는 네트워크 기반 원격제어 부분과 시스템의 각 내부 장치들간의 통신을 위한 간단한 직렬통신으로 나뉠 수 있다. 네트워크의 비약적인 발전에도 불구하고 내부 제어를 위한 통신부분은 현재까지 간단한 RS232기반을 사용하고 있다. 또한, 시스템의 개발기법은 각 기능단위의 모듈러 프로그래밍 기법에서 객체지향 프로그램으로 발전하였으며, 현재는 소프트웨어의 부품단위인 컴포넌트 기반 개발기법으로 발전하였다. 이는, 비즈니스 로직을 포함하는 독립적인 운영단위를 조립하며 새로운 시스템의 개발로 이어지는 기법으로서 소프트웨어 개발기법의 새로운 대안으로 제시되고 있다. 따라서, 본 연구는 컴포넌트 기반의 개발 기법을 적용한 GUI기반의 RS232C에서의 내부통신 Emulate를 구현하였다. 이는, 수신부와 송신부로 나뉘어지는 통신 제어부분을 컴포넌트화 하였으며, 이를 합성함으로서 제어부에서는 송,수신 데이터의 핸들링을 담당하도록 하였다.

• IEIE Transactions on Smart Processing and Computing
• /
• 제5권1호
• /
• pp.35-42
• /
• 2016

Developments in power electronics have enabled the widespread application of Pulse Width Modulation (PWM) inverters, notably for connecting renewable systems to the grid. This study demonstrates that a high-quality power can be achieved using a stand-alone inverter, whereby the comparison between the power quality of the stand-alone inverter with battery storage (off-grid) and the power quality of the utility network is presented. Multi-loop control techniques for a single phase stand-alone inverter are used. A capacitor current control is used to give active damping and enhance the transient and steady state inverter performance. A capacitor current control is cheaper than the inductor current control, where a small current sensing resistor is used. The output voltage control is used to improve the system performance and also control the output voltage. The inner control loop uses a proportional gain current controller and the outer loop is implemented using internal model control proportional-integral-derivative to ensure stability. The optimal controls are achieved by using the Sisotool tool in MATLAB/Simulink. The outcome of the control scheme of the numerical model of the stand-alone inverter has a smooth and good dynamic performance, but also a strong robustness to load variations. The numerical model of the stand-alone inverter and its power quality are presented, and the power quality is shown to meet the IEEE 519-2014. Furthermore, the power quality of the off-grid system is measured experimentally and compared with the grid power, showing power quality of off-grid system to be better than that of the utility network.

• 조명전기설비학회논문지
• /
• 제19권7호
• /
• pp.113-121
• /
• 2005

본 논문에서는 오존발생장치의 전원측 파형에 포함되는 고주파수의 노이즈를 제거하고, 디지털 궤환 제어에 의해 오존 출력을 제어하기 위하여 전원장치의 출력측 LC 필터와 방전관 용량으로부터 커패시터 전압과 전류를 검출하여 2중의 제어루프를 설계하였다. 디지털 제어기의 연산지연시간을 보상하기 위하여 연산지연시간을 전원장치 플랜트의 고유한 파라미터로 가정하고, 플랜트 모델에 포함시켜 모델링 하였다. 오존발생장치의 부하변동에 따르는 과도상태 응답특성을 개선하고, 파라미터 변동에 강인한 특성을 얻기 위하여 내부 전류 모델 제어기를 제안하였다. 또한 오존발생장치용 전원장치에서 영 오차의 정상 상태를 얻기 위하여 외부 전압 제어루프를 구성하여 비례 제어기와 공진 제어기를 병렬로 연결한 비례-공진 전압제어기를 제안하였다.

• Nuclear Engineering and Technology
• /
• 제41권6호
• /
• pp.807-812
• /
• 2009

An ICRF discharge cleaning and a fast wave electron heating experiment were performed. For automated operation and providing the diagnostics of the ICRF system, the ICRF local network was designed and implemented. This internal network provides monitoring, RF protection, remote control, and RF diagnostics. All the functions of the control system were realized by customized DSP units. The DSP units were tied by a local network in parallel. Owing to the distributed feature of the control system, the ICRF local control system is quite flexible to maintain. Developing the subsystem is a more effective approach compared to developing a large controller that governs the entire system. During the first experimental campaign of the KSTAR tokamak, the control system operated as expected without any major problems that would affect the tokamak operation. The transmitter was protected from harmful over-voltage events through reliable operation of the system.

• 대한한방내과학회지
• /
• 제22권3호
• /
• pp.415-422
• /
• 2001

Objectives: We aimed to identify the dose-dependent inhibitory effects of Yukmijihwang-tang-Hap-Sabaek-san(YMHSB) and Root cortex of Morus alba L.(RCM) on the mRNA expression of Interieukin(IL)-6, IL-S, granulocyte macrophage colony stimulating factor(GM-CSF) involved in the asthma model. Methods: In this study BEAS-2B cell lines, human epithelial cells, were used. These cells were stimulated by tumor necrosis $factor(TNF)-{\alpha},\;IL-1{\beta}$ and histamine for artificial inflammatory expression. ${\beta}-actin$ messenger RNA(mRNA) was used for the internal standard. After each 24 hours of the YMHSB and RCM treatment, total cellular RNAs were collected by treating RNA zol directly on the living cells. Then the transcriptional activities of IL-6, 8 and GM-CSF were measured by RT-PCR with electrophoresis. Results: In the YMHSB study, the mRNA expression of GM-CSF and IL-8 is significantly inhibited compared to that of control group. But the mRNA expression of IL-6 is not significantly inhibited. In the RCM study, the mRNA expression of GM-CSF and IL-S is significantly inhibited compared to that of control group. But the mRNA expression of IL-6 is not significantly inhibited. Conclusions: This study shows that YMHSB and RCM have dose-dependent inhibitory effects on the mRNA expression of IL-S and GMCSF in human epithelial cells. So these herbal medicines may inhibit the inflammatory process of asthma. Advanced studies are required to investigate the mechanisms of inhibition by herbal medicine in the asthma model.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1571-1574
• /
• 2003

A shared compliant control scheme based on IMC is proposed for the position-force force reflecting control system. The controller of the slave manipulator is designed by IMC method for the open loop unstable plant. The compliant control is implemented by first order low pass filter. In the proposed scheme, the slave manipulator well tracks the position of the master manipulator in free space and the compliance of the slave manipulator is autonomously controlled in contact condition. The simulation results show that the excellence of the proposed controller.

• Journal of Advanced Marine Engineering and Technology
• /
• 제38권10호
• /
• pp.1297-1302
• /
• 2014

This paper presents modern optimization methods for determining the optimal parameters of proportional-integral-derivative (PID) controller for coupled tank systems. The main objective is to obtain a fast and stable control system for coupled tank systems by tuning of the PID controller using the Particle Swarm Optimization algorithm. The result is compared in terms of system transient characteristics in time domain. The obtained results using the Particle Swarm Optimization algorithm are also compared to conventional PID tuning method like the Ziegler-Nichols tuning method, the Cohen-Coon method and IMC (Internal Model Control). The simulation results have been simulated by MATLAB and show that tuning the PID controller using the Particle Swarm Optimization (PSO) algorithm provides a fast and stable control system with low overshoot, fast rise time and settling time.

• 디지털융복합연구
• /
• 제18권8호
• /
• pp.111-118
• /
• 2020

본 연구는 내부통제시스템의 평가 및 공개가 기업의 경영자와 지배주주의 대리인 비용에 미치는 영향을 검증하기 위해 SSE상장기업을 대상으로 실증 분석하였다. 대리인 비용은 기업과 이해관계자와의 관계에서 정보의 비대칭으로 나타나는 회계정보의 가치평가에 영향을 주거나, 역 선택으로 나타나는 금융비용을 유발 할 수 있다. 그러므로 대리인 비용은 기업의 가치평가와 회계정보의 신뢰성에 부정적인 요인으로 작용될 수 있다. 따라서 정보비대칭을 감소시키려는 제도와 노력은 대리인 비용을 줄일 수 있다고 볼 수 있다. 기업의 대리인 비용이 적정한 경우 기업의 가치 평가도 상대적으로 양의 방향으로 움직일 수 있다. 본 연구에서는 내부통제시스템의 평가정보가 각각 경영자와 지배주주와의 대리인 비용과의 관계를 분석하기 위해 대용변수로 판매관리비비율과 지분비율을 통해 분석하였다. 또한 통제변수로 독립이사비율, 자본균형 비율, 기업규모 등을 투입하였으며, 분석결과 내부통제의 평가정보는 경영자 및 지배구조에 따른 대리인 비용에 관계가 있는 것으로 나타났다. 본 연구는 SSE상장기업의 내부통제의 평가에 따라 회계정보의 신뢰성 및 기업 가치 평가에 긍정적인 요인으로 작용될 수 있고 향후 관련기업의 회계정보 보고의 절차와 기업의 재무적 환경을 이해하는데 도움이 될 것으로 기대된다.

• 대한한방내과학회지
• /
• 제32권4호
• /
• pp.497-503
• /
• 2011

Objectives : To assess the effect of Bojungiki-tang for symptomatic management in stable asthmatic patients after initial treatment. Methods : Outcome measures of asthmatic patients were recorded using patient's charts and inquiry. Compared with the patient's state right after they got their treatment, "Excellent" was if it was almost the same state, "Good" was if the patient's state was maintained for almost 70%, "Fair" was for 50%, "Poor" was for under 50% or if the patient required another treatment. Results : Of 25 patients, 21 used Bojungiki-tang for more than one month and 20 maintained a stable state, that is, feeling more than 70% of symptom control compared with previous best status. Conclusions : Bojungiki-tang has a good effect for maintaining asthma after treatment.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
• /
• pp.436-439
• /
• 1995

In this paper we present a method to construct fuzzy model with multi-dimension input membership function, which can construct fuzzy inference system on one node of the network directly. This method comes from a common framework called Universal Learning Network (ULN). The fuzzy model under the framework of ULN is called Universal Learning Network-based Fuzzy Inference System (ULNFIS), which possesses certain advantages over other networks such as neural network. We also introduce how to imitate a real system with ULN and a control scheme using ULNFIS.