• 한국전산구조공학회논문집
• /
• 제23권1호
• /
• pp.27-35
• /
• 2010

본 논문에서는 지진이나 강풍과 같은 동적하중으로부터 구조물을 효과적으로 보호하기 위한 MR 감쇠기 기반의 스마트수동시스템의 제진성능을 파악하였다. 스마트 수동시스템은 MR 감쇠기와 MR 감쇠기의 전력원으로 사용하기 위한 전자기유도(Electromagnetic Induction, EMI)장치를 결합시킨 시스템이다. EMI 장치는 영구자석과 코일로 이루어져 있으며, MR감쇠기와 같이 구조물에 설치되어 구조물의 상대변위에 의해 발생하는 운동에너지를 Faraday의 전자기유도법칙에 따라 전기에너지로 변환시켜 감쇠특성을 변화시키기 위해 MR 감쇠기에 제공하게 된다. 스마트 수동 제어시스템은 기존의 MR 감쇠기 기반 반능동 제진시스템에서 필요로 하는 센서, 제어기, 전원공급장치 등의 피드백 제어시스템을 EMI 장치로 대체함으로써 훨씬 간편하고 설치 및 유지관리가 용이하게 된다. 본 연구에서는 6층 규모의 철골 구조물을 대상으로 다양한 역사지진 하중에 대한 진동대 실험을 통해 스마트 수동 제어시스템의 제진성능을 확인하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제55권6호
• /
• pp.292-298
• /
• 2006

Because of the high cost for the active power filter, passive filters have been widly used to eliminate harmonic currents of nonlinear load and can also improve the power factor. They are not often optimal filters because the passive filters are designed under the fixed load conditions. In this paper we proposed the method which only the necessary harmonic filters are operated by detecting the various harmonic current components. We presents the new control method of passive filter selection type with the relay control circuit which is consist of analog GIC, comparater, flip-flop and etc. By the experimental results using the proposed system for the rectifier load, we concluded that the researched method is cost effective and the performance is better than the passive filter.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2007년도 하계학술대회 논문집
• /
• pp.89-91
• /
• 2007

In this paper, we developed DSP based control system to automatically open and close passive filter, which is used to reduce harmonics, according to operating condition of loads. Passive filter control system automatically open and close each branch of filter according to working conditions of loads by sending signals to open and close installation of passive filter after measuring and monitoring voltage, current, harmonics, reactive power, power factor and so on. We verified it's performance by connecting control system with passive filter in the power line using the 100[HP] d.c. motor drive, opening and closing passive filter according to operation condition of motor, and measuring harmonics and reactive power, etc.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2002년도 학술대회지
• /
• pp.435-438
• /
• 2002

In this study, a new passive aerodynamic control method is proposed. Control plate which is oscillated by TMD-like mechanism makes flutter stabilizing airflow. Effectiveness of proposed model is verified by experimental and analytical study. In addition, various parameters of the proposed system are investigated. Applicability to long span bridge is also examined. According to the research results, proposed model is very effective in suppressing flutter, and it also shows remarkable robustness.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
• /
• pp.97-99
• /
• 2009

Bilateral teleoperation systems, connected to computer networks such as Internet have to deal with the time delay varying depending on factors such as congestion, bandwidth or distance. And the entire system is easy to become unstable due to irregular time delay. Passivity concept has been using as a framework to solve the stability problem in bilateral control of teleoperation. Acontrol scheme for teleoperation systems with varying time delay is proposed based on a passivity concept is proposed in this paper. One approach makinguse of the characteristic impedances is proposed to achieve a passive control. Since passive control does not mean that the system performance will be acceptable, another transmission scheme which focuses on both the passive feature and the acceptable performance is configured for varying time delay in this paper. The tracking performance has been proved through the computer simulation for varying time delay bilateral teleoperation system using Matlab Simulink.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.497-504
• /
• 2005

Stay cables, such as are used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Several methods have been proposed and implemented to mitigate this problem, though each has its limitations. Recently some studies have shown that active and semiactive control system using MR (Magnetorheological) damper can potentially achieve both higher performance levels than passive control system and adaptability with few of the detractions. However, a control system including a power supply, controller, and sensors is required to maximize the performance of the MR damper and this complicated control system is not effective to most of large civil structures. This paper proposes a smart passive damping system using MR dampers by introducing electromagnetic induction (EMI) system as an external power source to MR damper and verified the performance of smart passive damping system for mitigating the vibration of stay cables. The performances of smart passive damping system are compared with those of linear viscous damper and passive-mode MR damper.

• 대한물리의학회지
• /
• 제11권1호
• /
• pp.35-43
• /
• 2016

PURPOSE: The purpose of this study was to investigate the effects of passive stretching exercises of the scalene muscles known as respiratory accessory muscles, on forced vital capacity. METHODS: Ten of the participants were randomly selected as an experiment group to perform passive stretching exercises on the scalene muscles. Ten additional students were selected randomly as a control group. The forced vital capacity was assessed by using a digital spirometer (Pony FX, COSMED Inc, Italy) both before and after the passive stretching exercises were performed. Subsequently, passive stretching exercises of the scalene muscles were performed in the experimental group. There were no interventions to the control group. RESULTS: As for the forced vital capacity (FVC), the experiment group showed significant increase in items of forced vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$), peak expiratory flow (PEF), forced expiratory volume in 1 second/vital capacity ($FEV_1/VC$), and maximal expiratory flow 75%(MEF 75%) after the scalenemuscles passive stretching exercises were performed. The control group, however, showed no change. CONCLUSION: This study demonstrated that passive stretching exercises of the scalene muscles could be helpful for forced vital capacity improvement.

• 한국지진공학회논문집
• /
• 제10권6호
• /
• pp.37-46
• /
• 2006

본 연구에서는 면진 건물의 내진 성능을 개선하기 위하여 최근 개발된 스마트 수동 제어 시스템을 적용하고 이의 효용성을 수치 모의실험을 통해 검증하였다. 스마트 수동 제어 시스템은 효과적인 반능동 제어 장치로 알려진 MR 감쇠기에 전자기 유도부를 도입하여 응답 변화에 따라 MR 감쇠기로 입력되는 전류를 변화시킴으로써 MR 감쇠기의 감쇠 특성을 조절하는 새로운 개념의 스마트 제진 시스템이다. 스마트 수동 제어 시스템에서 전자기 유도부는 영구자석과 솔레노이드 코일로 구성되며, 기존 스마트 제진 시스템의 계측기, 제어기, 외부 전원장치를 한꺼번에 대체할 수 있다. 면진 건물에 대한 스마트 수동 제어 시스템의 내진 성능을 수치적으로 검증하기 위하여 미국토목학회에서 제시한 면진 건물에 대한 벤치마크 제어 문제를 활용하였다. 스마트 수동 제어 시스템의 제진 성능을 MR 감쇠기를 이용한 기존 스마트 제어 시스템의 성능과 비교하였다. 수치 모의실험 결과를 통해 스마트 수동 제어 시스템이 면진 건물의 내진 성능을 개선하는 데 매우 유용함을 확인하였다.

• 로봇학회논문지
• /
• 제4권4호
• /
• pp.273-280
• /
• 2009

It is difficult to find a practical solution for the backward-motion control of a car-like mobile robot with n passive trailers. Unlike an omni-directional robot, a car-like mobile robot has nonholonomic constraints and limitations of the steering angle. For these reasons, the backward motion control problem of a car-like mobile robot with $n$ passive trailers is not trivial. In spite of difficulties, backing up a trailer system is useful for parking control. In this study, we proposed a mechanical alteration which is connecting $n$ passive trailers to the front bumper of a car to improve the backward motion control performance. Theoretical verification and simulations show that the backward-motion control of a general car with n passive trailers can be successfully carried out by using the proposed approach.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
• /
• pp.338-345
• /
• 2002

This paper presents a hybrid control strategy for seismic protection of a benchmark cable-stayed bridge, which is provided as a testbed structure for the development of strategies for the control of cable-stayed bridges. In this study, a hybrid control system is composed of a passive control system to reduce the earthquake-induced forces in the structure and an active control system to further reduce the bridge responses, especially deck displacements. Lead rubber bearings and ideal hydraulic actuators are used fur the passive and active control systems. Bouc-Wen model is used to simulate the nonlinear behavior of lead rubber bearings and an H₂/LQG control algorithm is adopted as an active control algorithm. Numerical simulation results show that the performance of the proposed hybrid control strategy is superior to that of the passive control strategy and slightly better than that of the active control strategy. The proposed control method is also more reliable than the fully active control method due to the passive control part. Therefore, the proposed hybrid control strategy can effectively be used to seismically excited cable-stayed bridges.