• 한국군사과학기술학회지
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• 제2권2호
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• pp.83-91
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• 1999

Dynamic characteristic of manufacturing stage is understood and the utilization of each machine is maximized by developing on-line dynamic CAPP system to consider the overloads in the aircraft part manufacturing line. In this paper, a scheme of production planning and scheduling system was proposed through inspection about some predeveloped CAPP system. Developed production planning and scheduling system included process planning module. After precise inspection of some FMS line schema at domestic heavy industry, optimized FMS line was applied to aircraft part manufacturing and repairing factory. By virtue of considering overloads of factory and machine through on-line dynamic CAPP system, the utilization of resources is maximized and manufacturing lead time is minimized.

• 전자공학회논문지 IE
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• 제45권4호
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• pp.74-79
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• 2008

본 논문은 교도소 출입문의 모든 개폐 현황과 정보를 온라인 네트워크를 통하여 중앙의 통제실에서 실시간으로 확인할 수 있도록 하고, 실별, 층별로 위치한 다수의 출입문 개폐동작을 개별 또는 병렬로 동시에 동작할 수 있도록 하는 중앙통제에 의한 양방향 제어시스템을 구성하였다. 현재 사용 중인 125kHz대 RFID기술의 단점을 보완하기 위해서 13.55MHz대 RFID 기술을 적용하여 보안 및 신뢰성 문제를 해결하였으며, 비정상적으로 문이 열릴 경우 경광등 및 경보음을 울리도록 하는 온라인 통제 및 관리 시스템을 개발하였다.

• 산업융합연구
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• 제6권1호
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• pp.3-16
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• 2008

Musculoskeletal Disorders are usually caused or aggravated by poor work processes and unsuitable working conditions - that involve repetitive or forceful movements or the maintenance of constrained or awkward postures. The condition is characterized by discomfort and persistent pain. An investigation on the risk factors of musculoskeletal should have done one time per three years. Cause of musculoskeletal disorders for assembly line worker was a low back pain(LBP). Recommendations of improvement for productivity are redesign of working conditions, exercise, prevent of musculoskeletal disorders and avoiding stress.

• 한국안전학회지
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• 제38권2호
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• pp.104-111
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• 2023

Rolling stock maintenance, which focuses on preventive maintenance, is typically implemented considering the potential harm that may be inflicted to passengers in the event of failure. The cost of preventive maintenance throughout the life cycle of a rolling stock is 60%-75% of the initial purchase cost. Therefore, ensuring stability and reducing maintenance costs are essential in terms of economy. In particular, private railroad operators must reduce government support budget by effectively utilizing railroad resources and reducing maintenance costs. Accordingly, this study analyzes the reliability characteristics of components using field data. Moreover, it resolves the problem of determining an economical replacement interval considering the timing of scrapping railroad vehicles. The procedure for determining the optimal replacement interval involves five steps. According to the decision model, the optimal replacement interval for the onboard signal device components of the "A" line train is calculated using field data, such as failure data, preventive maintenance cost, and failure maintenance cost. The field data analysis indicates that the mileage meter is 9 years, which is less than the designed durability of 15 years. Furthermore, a life cycle in which the phase signal has few failures is found to be the same as the actual durability of 15 years.

• 한국철도학회논문집
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• 제11권2호
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• pp.165-175
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• 2008

철도판형교에 있어 선받침은 사용 중에 많은 문제를 야기하고 있으며, 구조적으로 불안정하다. 기존 선받침의 문제점을 파악하기 위해 수평저항능력 실험을 수행하였다. 유지보수에 용이하고 들림현상에 저항할 수 있는 개선된 스페리칼받침을 개발하여 기존받침을 교체하였다. 개선된 스페리칼받침의 교체성능 실험과 부반력 저항능력 실험이 수행되어, 유지보수 성능 및 부반력 저항능력이 증명되었다. 선받침 상태 및 스페리칼받침으로 교체된 상태에서 판형교의 동적 거동 및 각 교량받침의 동적 거동을 계측하여 거동의 차이를 분석하였다. 이러한 실험 및 분석을 통하여 개선된 스페리칼받침이 철도 판형교에 교량받침으로 사용하기에 적합함을 알 수 있었다.

• 전기학회논문지P
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• 제58권2호
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• pp.101-107
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• 2009

This paper deal with development of on-line type voltage sag compensation system using supercapacitor EDLC to solve the voltage sag problems which are considered to be dominant disturbances affecting the power quality. With the wide use of semiconductor devices in electrical equipment, modem-type loads are becoming increasingly sensitive to the voltage sags and the disturbances prove to be costly to industries. Supercapacitor EDLC is employed to compensate dynamically for the voltage sag of system with sensitive loads. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. Therefore, in this paper, the energy design scheme of supercapacitor and the configuration technique of on-line type voltage sag compensation systems are newly introduced. According to the results of experimental of prototype 5[kVA] system, it is verified that the developed system has effectiveness of voltage sag compensation by using a supercapacitor EDLC.

• 조명전기설비학회논문지
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• 제19권1호
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• pp.162-168
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• 2005

본 논문은 조명시설 관리에 따른 유형을 파악하고 이에 맞는 관리 모델을 제안하며, 각 관리 모델에 적합한 온라인/오프라인 조명시설 관리 시스템의 개발에 관하여 연구한 내용이다. 또한 연구 결과물의 효용성을 높이기 위해 실제 사용하는 양식을 기초로 개발하여 새로운 시스템의 적용시 적응이 용이하도록 하였다. 제안된 관리 모델에 따른 온라인/오프라인 조명시설 제어를 통하여 조명시설 정보의 효과적인 운용이 가능하게 하였으며, 인력 및 유지보 수비를 줄이는데 기여할 수 있을 것으로 기대된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.66-71
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• 2006

A geometric contact conditions of wheel/rail affect the dynamic behavior of rolling stock. Mechanical force acted on the wheel/rail causes excessive wear and increase the maintenance cost. In this study, we have studied the dynamic behavior of the urban railway vehicle with new and worn wheel by VAMPIRE program. And we have tested the accelerations of wheelset on the conventional line. The results of simulation are compared with the measuring data of field test. It shows that the acceleration of worn wheel is greater than the acceleration of new wheel in the straight track line but on the contrary, the acceleration of new wheel is greater than the acceleration of worn wheel in curved track. That results explain that the new wheel is worn out greater than the worn wheel in curved track line and need to be maintained more seriously when running in curved track line.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1175-1178
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• 2004

On-line partial discharge(PD) monitoring system has been developed to monitor in operating large motor stator insulations. This system makes use of remote diagnosis techniques for the evaluation of PD activity in the control center of thermal power plant. This system can be remotely accessed via a modem to build database, analyze status and interpret the pattern of PD activity. A personnel computer is generally connected to ten motors to continuous measurement of the PD activity. The test data can be easily interpreted by a maintenance staff. For assessing the condition of stator winding in motors, this system ensures a reliable measurement and accurate estimation. Capacitive couplers used for on-line PD measurement have been 80pF. The maximum PD magnitude(Qmax), PD pattern and normalized quantity number(NQN) were performed by this system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.149-156
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• 2003

Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as riskbased inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system, which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.