• Current Applied Physics
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• 제18권11호
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• pp.1388-1392
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• 2018

Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

• 드라이브 ㆍ 컨트롤
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• 제17권1호
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• pp.37-43
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• 2020

An intelligent excavator can be divided into Machine Guidance (MG), semi-automatic, and unmanned by technology. The MG technology excavator is equipped with a tilt sensor on each link of the excavator and a GPS is installed on the excavator body to inform the user of the position of the excavator bucket end. Machine control (MC) technology that assists the user's work can be divided into semi-automatic and fully automatic technology. The semi-automatic MC equipment has already been commercialized by Komatsu and Caterpillar. The MC excavator is equipped with an electro-hydraulic system, sensors and controllers to control the excavator bucket end according to the user's needs. In this study, the semi-automated excavator modified based on manual excavator, is equipped with an electro-hydraulic system, a controller system, multi-sensors and a control algorithm is developed to assist in excavation work such as leveling and grading. By applying the developed technology, it was possible to confirm productivity improvement compared to manual digging and leveling work. In the future, further research to improve the accuracy of the hydraulic precision control and collaborative work with heterogeneous construction equipment such as dump truck and automated collaboration tasks technology could be developed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.143-145
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• 2007

The development of excitation control system (ECS) for emergency diesel generator in nuclear power plant is the replacement project of existing control system to resolve the maintenance problems caused by aging and obsolescence, The excitation control system is classified as a safety-related system. To guarantee the performance of developing excitation control system is equal to or higher than that of other systems, establishing the quality assurance scheme, doing software verification and validation activities, and planning equipment qualification. In this paper, we'd like to introduce the equipment qualification of excitation control system.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.677-684
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• 2017

스마트 기기는 휴대하기 편리하고 애플리케이션이 개발이 쉬운 장점으로 다양한 산업 분야에 적용되고 있다. 그러나 산업용 장비 분야에서는 장비에서 제공되는 정보에 대한 보안 문제 및 원격지에서 장비의 액추에이터를 제어할 경우 사고가 발생할 수 있다. 본 논문에서는 위 문제에 대한 해결 방법과 스마트 제어 시스템을 산업용 자동화 장비에 적용할 경우 장점에 관한 연구를 수행하였다. 이런 문제 해결을 위해 장비 조작 시 발생할 수 있는 사고에 대해 질의를 이용한 매뉴얼 조작 방법과 스마트 기기를 이용한 장비 제어 시 스마트 제어 접근 허용 절차를 제안하였으며, 통신 데이터 보호 및 사용자 인증 방법으로 다중 암호화 프로토콜을 이용한 데이터 전송 방법과 단말기 고유 정보 및 Q&A를 이용한 사용자 인증 방법 제안하였다. 구현된 스마트 제어 시스템의 성능을 평가하기 위해 스마트 제어 시스템의 동작 실험과 사용자 인증 비교 실험을 하였으며, 장비에 적용 시 장점을 파악하기 위한 실험에서 스마트 제어 시스템은 티칭 팬던트 보다 편리하게 티칭 조작이 가능하였고, 다양한 정보 취득과 하드웨어 조작이 가능하였다. 또한, 스마트 제어 시스템 적용 시 장비의 에러 조치 시간을 약 13% 단축할 수 있었다.

• 전기학회논문지
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• 제63권5호
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• pp.703-712
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• 2014

To improve the efficiency and safety of railway systems, the train control system has been considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing the information and communication technologies (ICT). Accordingly, since the ICT-based train control system makes the railway system be simplified (i.e. the heavy ground-equipment can be removed), the efficient and cost-effective railway system can be realized. In this paper, we perform the feasibility test of the ICT-based train control system via a simulation. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the Consecutive operation test for prototypes of the on-board controller, wayside object control units and local control computer.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.291-298
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• 2000

This paper describes a theoretical and experimental investigation into an active vibration isolation system in which four electromagnetic actuators are installed in parallel with each of four passive mounts placed between a piece of equipment and a vibrating base structure. Decentralised velocity feedback control is employed, where each actuator is operated independently by feeding back the absolute equipment velocity at the same location. Although one end of each actuator acts at the sensor positions on the equipment, the control system is not collocated because of the reactive forces acting on the flexible base structure, whose dynamics are strongly coupled with the mounted equipment. Isolation of low frequency vibration is considered where the equipment can be modelled as a rigid body and the mounts as lumped parameter springs and dampers. Control mechanisms are discussed, and some experimental and simulation results are reported.

• KIEAE Journal
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• 제7권5호
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• pp.73-80
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• 2007

Indoor climate control equipments is used to make the indoor environment more comfortable when indoor condition is not satisfactory to inhabitants. In this study, which instrument is preferred to control indoor climate and which is not preferred were surveyed with questionnaire. With this result, the needs of dwellers and wanting performance of housing could be revealed. Results are followings 1) The satisfaction ratio and equipment possession ratio of apartment houses' is higher than that of detached dwelling's 2) It is recognized for inhabitants that air cleaner is the mostly used equipment and best equipment for indoor comfort. 3) Electronic fomentation mat is recognized as the most problematic equipment for securing inhabitant's comfort. And air conditioner is considered negative for 60% of responser's. As grow older, this trend is increasing.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.803-804
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• 2016

독일의 'Industry 4.0'의 등장으로 제조 산업에 ICT를 융합하여 생산능력을 극대화하는 스마트 팩토리 구현과 관련한 많은 연구가 진행되고 있다. 그러나 현재의 시스템은 장비의 임베디드 시스템에 선언된 데이터를 통해 설비를 제어하는 중간 수준의 스마트 팩토리에 머무르고 있다. 본 논문에서는 스마트 팩토리 구현을 위해 장비의 변수 정보를 D/B화하여 장비를 제어하는 IoT 기반의 장비 제어방법을 제안한다. 제안하는 방법은 장비 내에 설치된 모든 제어장치의 변수를 서버의 D/B table에서 호출하여 변수로 사용한다. 이러한 방법을 사용할 경우 적은 네트워크 자원으로도 다수의 장비를 보다 빠르게 제어할 수 있어 공장의 효율적인 운영이 가능할 것이다.

• 임상간호연구
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• 제16권2호
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• pp.69-84
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• 2010

Purpose: The purpose of this study was to identify the state of infection control in neonatal intensive care units (NICUs) including disinfection methods, disinfection cycles, and exchange cycles for medical devices and to suggest a basic framework which would help develop standardized infection control guidelines. Methods: From a list of NICU equipment developed from the NICUs in 4 tertiary hospitals, a structured questionnaire on 74 types of medical equipment was developed and sent to 31 hospitals by mail. The results were reviewed by panel of experts (56 persons), and analyzed for internal validity by a focus group (4 persons) using guidelines from the Centers for Disease Control and the Korean Hospital Nurses Association. Results: The results showed various methods, cycles, disinfectant levels for the disinfectants and exchange cycles in the medical equipment infection control of the 31 hospitals. The focus group developed a 66-item basic framework based on validity testing. Conclusion: From the results of this study, a framework of infection control standards for 66 types of medical equipment in the NICU was developed. It is suggested that further study be done to more precisely establish standard infection control guidelines for NICU medical equipment.

• 산업기술연구
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• 제27권A호
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• pp.61-67
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• 2007

The construction machine is the composite machine assembled by about 30,000 parts. Excavator, one kind of a construction machine, plays the leading role for export of construction equipment. It is generally impossible to produce all of the items within one company. Especially the supply of hydraulic control valves, one of the core part of the construction equipment, depends on the import heavily. So it is important to make an efficient production plan of hydraulic control valves in the company. The most important thing for the production scheduling of a hydraulic control valve is to make production schedule keeping the start date for assembly line for an excavator and to make minimization of the stock level. The production plan of hydraulic control valve includes the decision of the quantity supplied by subcontractor. This paper presents a scheme for a scheduling system of the hydraulic control valve considering the schedule of the assembly line for excavator production. This paper provides a methodology, which can make a plan of supply and production and generate a detailed schedule for daily production.