• 전력전자학회논문지
• /
• 제22권2호
• /
• pp.102-108
• /
• 2017

Proper design guides are proposed for a practical dual-active bridge (DAB) converter based on the mathematical model on the steady state. The DAB converter is popular in bidirectional application due to its zero-voltage capability and easy bidirectional operation for seamless control, high efficiency, and performance. Some design considerations are taken to overcome the limitation of the DAB converter. The practical design methodology of power stage is discussed to minimize the conduction and switching losses of the DAB converter. Small-signal model and frequency response are derived and analyzed based on the generalized average method, which considers equivalent series resistance, to improve the dynamics, stability, and reliability with voltage regulation of the practical DAB converter. The design of closed-loop control is discussed by the derived small-signal model to obtain the pertinent gain and phase margin in steady-state operation. Experimental results of a 3.3 kW prototype of DAB converter demonstrate the validity and effectiveness of the proposed methods.

• 실천공학교육논문지
• /
• 제10권2호
• /
• pp.89-94
• /
• 2018

사출 성형에서 금형 온도는 성형품의 품질에 큰 영향을 준다. 어느 정도의 온도가 적정한가는 성형 재료, 성형품에서 요구되는 품질에 의해서 결정되고 중요한 것은 그 온도가 안정적이어야 한다. 먼저 그 수지에 적합한 금형 온도 조건 범위 내에서 성형품이 요구하는 품질에 맞는 금형 온도를 설정해야 한다. 즉, 성형품의 표면 광택, 성형 사이클의 단축, 변형 방지, 수축 및 수지 흐름의 용이성 등의 중요성에 의해서 금형 온도는 변화한다. 실질적인 금형 기술 향상을 위해서 사출 금형을 설계하고 제작하는 산업체에서 적용할 수 있는 온도 제어에 대한 애로 기술 과정의 훈련 모형을 제시하고자 한다.

• Structural Engineering and Mechanics
• /
• 제14권1호
• /
• pp.21-38
• /
• 2002

A control algorithm combining viscous and non-linear Reid damping mechanisms has been recently proposed by the authors to command active friction dampers. In this paper, friction dampers and the proposed algorithm are applied to control the seismic responses of a nonlinear 20-story building. Piezoelectric stack actuators are used to implement the control algorithm. The capacity of each damper is determined by the practical size of piezoelectric actuators and the availability of power supply. The saturation effect of the actuators on the building responses is investigated. To minimize the peak story drift ratio or floor acceleration of the building structure, a practical sequential procedure is developed to sub-optimally place the dampers on various floors. The effectiveness of active friction dampers and the efficiency of the proposed sequential procedure are verified by subjecting the building structure to four earthquakes of various intensities. The performance of 80 dampers and 137 dampers installed on the structure is evaluated according to 5 criteria. Numerical simulations indicated that the proposed control algorithm effectively reduces the seismic responses of the uncontrolled 20-story building, such as inelastic deformation. The sub-optimal placement of dampers based on peak acceleration outperforms that based on peak drift ratio for structures subjected to near-fault ground motions. Saturation of piezoelectric actuators has adverse effect on floor acceleration.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.1045-1046
• /
• 2010

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
• /
• pp.481-483
• /
• 2005

There is change of signal control system for train control worldwide current. This is train control system that use radio communication and step practical use Tuesday. Research for diversified application, examination and enforcement is achieved in internal railroad industry by this. Therefore, do examination of universal train radio control way for internal application. Studied train control way that use suitable radio communication to internal railroad.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권19호
• /
• pp.8239-8244
• /
• 2014

The Cancer Control Act in Japan became effective in 2006. In Ibaraki, Toyama, and Hyogo prefectures, the Cancer Control Promoter (CCP) plan was created to strengthen partnerships for cancer prevention. This study aimed to examine the curre nt status of CCP utilization and analyze relationships with intersectoral collaboration, both within the government and with outside partners. In 2008, we mailed questionnaires to 100 administrators responsible for disease prevention and health promotion in municipal governments of the three prefectures. Ninety-one administrators responded (response rate, 91.0%). We analyzed responses to questions regarding whether or not the municipalities had used CCPs. Items assessing intersectoral collaboration examined municipality characteristics and relationships with outside partners and sectors specializing in areas other than community health. Among 90 administrators with valid data, 33 municipalities (36.7%) used CCPs while 57 (63.3%) did not. The Fisher's exact test revealed that intersectoral collaboration for using CCPs was associated with communication with all of the municipal government sectors not related to health. The present study indicated that CCPs were not consistently used in municipalities. However, we found that intersectoral collaborations, especially within the local government, may be related to the practical use of CCPs. This, in turn, may result in effective cancer control and prevention, as well as improvement in community health.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.1199-1205
• /
• 1993

It has been well known that the assumption of full state availability is one of the most important restrictions to the practical realization of VSCS. And several attempts to alleviate the assumption had been made. However, it is not easy to find a positive scheme among them. Recently, an output feedback variable structure control system(OFVSCS) was proposed and the effectiveness of the scheme was validated for the disturbance free systems. The purpose of this study is to propose a robust OFVSCS that have the robust properties against process parameter variations and external distrubances by extending the basic OFVSCS and to evaluate its control performances through power system stabilizer design example. The ROFVSCS is composed of dynamic switching function and output feedback switching control inputs that are constructed by the use of the unknown vector modeling technique. With the proposed scheme, existence of sliding mode is guaranteed and any nonzero bias can be suppressed in the face of disturbances and process parameter variations as far as well-known matching condition is satisfied. Due to the fact that the ROFVSCS is driven by small number of measured informations, the practical application of VSCS for the systems with unmeasurable states and for high order systems that conventional schemes cannot be applied, is possible with the proposed scheme. It is noticeable that the implementation cost of VSCS can be considerably reduced without sacrifice of control performances by adopting ROFVSCS since there is no need measure the states with high measurement cost.

• 한국지능시스템학회논문지
• /
• 제21권2호
• /
• pp.192-197
• /
• 2011

본 논문은 선형 상태 관측기의 성능 및 실용화 검증을 위하여 도립진자 시스템의 출력 피드백 제어 실험을 수행하였다. 도립진자 시스템으로는 (주)셈웨어의 CEM-IP-01를 실험에 사용하였다. 동역학 해석을 위하여 라그랑지안 방정식 및 자코비안 선형화 방법을 이용하였고, 모의실험을 통하여 일반 상태 피드백 제어기의 출력 응답과 제안된 제어기의 출력 응답을 먼저 비교 분석하였다. 마지막으로 실제 도립진자 시스템에 적용함으로써 제어기 구현에서 발생하는 문제점을 파악하고 해결함으로써 실용화 가능성을 직접 확인하였다.

• 전력전자학회논문지
• /
• 제26권2호
• /
• pp.127-134
• /
• 2021

This study presents an overhang-type rail traction system using dual brushless AC (BLAC) motors with hall sensors. For an accurate position and moving length control of the designed rail traction system, instantaneous position controller using speed reference model and modified disturbance observer for BLAC motor with hall sensor are proposed. The presented speed reference model is designed to satisfy the required performance of 200 mm/s with proper acceleration and deceleration slopes to reduce mechanical vibration. Through the instantaneous speed reference model, instantaneous position and speed errors can be compensated together. Furthermore, the modified disturbance observer for BLAC motors with low-resolution hall sensors can improve the torque and speed control performance. The proposed disturbance observer is based on an actual motor speed. However, the feedback speed information of the hall sensor is not enough for use in the low-speed region. The practical adopted disturbance observer uses an activation speed band to the actual torque controller of the designed rail traction system. The proposed position control scheme is verified by the MATLAB-Simulink model and a practical manufactured traction system. In the computer simulation and experiments, the proposed position control scheme shows advanced control performance.

• 한국가정과교육학회지
• /
• 제22권2호
• /
• pp.61-79
• /
• 2010

본 연구는 현장에서 '생애설계와 진로탐색' 단원의 효과적인 수업을 위한 기초자료를 제공하고 도서관을 활용한 실천적 문제 중심 학습의 활용 가능성을 제시하는데 목적을 두고 설계되었다. 제7차 교육과정 고등학교 10학년 12종 교과서의 '생활설계' 단원과, 2007 개정 교육과정 해설서의 9학년 '생애설계와 진로탐색' 단원에 대한 내용을 분석한 결과를 바탕으로 실천적 문제를 정의하고 '생애설계와 진로탐색' 단원의 내용을 재구성하여 10차시의 학교도서관을 활용한 실천적 문제중심 가정과 교수-학습 과정안을 개발하였다. 경기도 S고등학교의 재학생 139명을 대상으로 실험집단에는 개발된 학교도서관을 활용한 문제중심 수업을 도서관에서, 비교집단에는 동일주제를 가지고 교실에서 수업을 진행한 후 '생애설계와 진로탐색' 단원에 대한 의식 및 태도와 가정과에 대한 인식의 향상정도를 공변량 분석(ANCOVA)으로 알아보고, 학생의 수업방법에 대한 만족도를 살펴보았다. 연구결과, 개발된 도서관을 활용한 실천적 문제중심 수업은 교실에서의 실천적 문제중심 수업보다 '생애설계와 진로탐색'과 관련된 바람직한 의식과 태도를 형성하고 발전시키는데 크게 영향을 미치는 것으로 나타났다. 또한, 가정교과를, 과학지식을 가정생활에 응용하는 능력을 기르는 교과, 가정과 연결된 사회문제 분석 능력을 기르는 교과, 주변사람들을 돌보고 존중하는 능력을 기르는 교과, 현대사회에서 중요한 교과라고 긍정적으로 인식하게 하는데 영향을 미치고 있었으며, 수업방법과 수업 전반에 대한 학생들의 만족도가 매우 높은 것으로 나타났다.