• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.63-68
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• 2017

In order to process more complicated and higher-precision parts, generally, an additional axis for a machine tool is needed which was an approach to minimize the cost of tool modification. A table with a rotary reducer that can rotate through the axis of the gear system was employed to a machine tool to achieve the purpose of adding an extra motion axis. In general, the motion of the rotary reducer is driven by a worm/wheel or helical gear system, which is different from the hypoid helical gear structure that used in this research. Reliability of guarantee of high accurancy throughout the whole life cycle is on of the critical factors to evaluate a rotary reducer in this field. In this paper, in order to evaluate life-time of rotary reducer, a low-cost accelerated life test was developed to satisfy the demands of clients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.79-84
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• 2010

In this paper, we developed the BMSWare(Bridge Management System Middleware) for bridge safety surveillance in real time processing. The developed system operates on web and considers the general monitoring application for bridges. In various environments in geographical location of bridge, it can obtain reliably data from various logger and sensors without re-programming. The main functions of the developed system include the acquisition, processing, backup and transmission of the collected sensor data. It was proved to be the safety and effectiveness by application of Mooyeong bridge.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.1-8
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• 2019

Modern weapon systems are multifunctional, with capabilities for executing complex missions. However, they are required to be highly reliable, which increases their total cost of ownership. Because it is necessary to produce the best results within a limited budget, there is an increasing interest in development, acquisition, and maintenance costs. Consequently, there is a need for tools that calculate the lifecycle costs of weapons systems development to facilitate decision making. In this study, we propose a cost calculation function based on the Markov process simulator-a reliability, availability, and maintainability analysis tool developed by applying the Markov-Monte Carlo method-as an alternative to these requirements to facilitate decision-making in systems development.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.334-339
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• 2004

Ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products. Also, the method of micro-grooving using micro endmilling is used widely owing to many merit, but has problems of precision and quality of products due to tool wear and tool fracture. This investigation deals with state monitoring using acoustic emission(AE) signal in the micro-grooving. Characteristic evaluation of AE raw signal, AE hit and frequency analysis for state monitoring is also presented in the paper.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.8-13
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• 2000

Die polishing technology is very critical to determine quality and performance of the final products. Die polishing processes have not been automated because the automation requires a great deal of experience and skill of experts. Thus, to implement a fully automated polishing process, the development of polishing status monitoring system replacing the skill of experts is critical. AE is known to be closely related to material removal rate(MRR). As the surface is rougher, MRR gets larger and AE increased. The surface roughness can be indirectly estimated using the AE signal measured during automatic die polishing process. In this study, The polishing state monitoring system using AEms signal was developed. This system can be not only to monitor the abnormal state but also to estimate a state of surface roughness of polishing surface qualitatively.

• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.58-60
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• 2005

초고압 선로에 대한 풍부한 진단 경험과 축적된 Know-how를 바탕으로 선로의 이상유무를 원격으로 진단, 감시하는 On-line PD Monitoring System을 개발하였다. 초고압 선로의 이상 유무를 활선상태에서 정밀하게 진단할 수 있는 전기적인 측정방법으로 부분방전이 유일하다. 그러나 부분방전 신호는 미약하고 주위 노이즈와 구분이 어렵기 때문에 측정 뿐만 아니라 분석하기가 어렵다. 부분방전 측정 장비는 이러한 노이즈를 효과적으로 제거하고 측정된 신호를 의미있는 정보로 가공하여 사용자에게 제공해 주어야 한다. 본 논문에서는 이러한 조건들을 충족하는 고성능의 원격 진단시스템에 관하여 서술하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.2-4
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• 2013

최근 아날로그 기기의 생산중단 및 디지털 시스템들의 고도화에 따라, 가장 보수적인 산업분야인 원자력 분야에도 디지털 기술이 적용되고 있다. 정보처리시스템은 정보의 취득, 처리, 기록, 가공과 관련된 제반의 기능을 수행하여 원자로의 상태 감시 및 제어를 지원하는 중요한 시스템이다. 이러한 정보처리시스템은 대규모 발전소 또는 소규모 연구로 등 그 규모에 따라서 다양하게 설계될 수 있다. 본 논문에서는 국내에 사례가 매우 드문 연구용 원자로의 정보처리시스템에 대하여, 시스템이 갖추어야 할 안전성 요건 및 운전성 요건을 분석 및 정의하고 이를 만족하는 통합 정보처리시스템의 개념 설계 결과를 소개한다. 연구결과는 국내외 중/소 규모 플랜트의 정보처리시스템 설계에 활용될 수 있을 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.901-904
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• 2008

센서 네트워크를 이용하여 교량을 실시간으로 관리하기 위하여 미들웨어를 사용한다. 그러나 현재 미들웨어는 단순히 센서 네트워크에서 수집한 자료를 처리하는 단순한 수준에 불과하다. 본 논문에서 실시간으로 센서로부터의 정보를 수집/가공하고 센서 노드들과 전용 애플리케이션 및 웹 브라우저 간의 중재 역할을 하는 미들웨어를 제안한다. 또 데이터베이스 고장이 발생하였을 경우 파일로 수집정보를 저장 하며 데이터베이스가 복구되었을 때 데이터베이스 부하를 줄이기 위하여 데이터베이스의 사용률이 적을 때 파일로 수집된 정보를 데이터베이스에 저장하는 기능을 제안한다. 그리고 실시간으로 교량정보등을 감시하여 이상이 발생하였을 때 경고 메시지를 발생시켜 관리자가 교량의 비정상적인 상태에 대하여 빠르고 쉽게 인지할 수 있는 메커니즘을 제안한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.36-42
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• 2021

This study was conducted to analyze the effect of the gear specification and gear quality corresponding to the macro geometry on the gear transmission error. The two pairs of gears with large and small transmission errors were selected for calculation, and two pairs of gears were manufactured with different gear quality. The test gears were manufactured by two different gear specifications with ISO 5 and 8 gear quality, respectively. The transmission error measurement system consists of an input motor, reducer, encoders, gearbox, torque meter, and powder brake. To confirm the repeatability of the test results, repeatability was confirmed by performing three repetitions under all conditions, and the average value was used to compare the transmission error results. The transmission errors of the gears were analyzed and compared with the test results. When the gear quality was high, the transmission error was generally low depending on the load, and the load at which the decreasing transmission error phenomenon was completed was also lower. Even when the design transmission error according to the gear specification was different, the difference of the minimum transmission error was not large. The transmission error at the load larger than the minimum transmission error load increased to a slope similar to the slope of the analysis result.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.686-689
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• 1990

For the monitoring of kimchi fermentation states, pressure detecting sensor and monitoring device were designed and fabricated. The system was consisted of an air tight fermenting tube(31.5 ml), strain gauge type pressure sensor and signal processing device built with operational amplifier and A/D converter, and interfaced to personal computer. Chiness cabbage kimchi was fermented in the plastic container($150{\times}220{\times}160mm$) at $25^{\circ}C\;and\;30^{\circ}C$. The fermentation was monitored with fermenting tubes containing kimchi. The pressure based kimchi fermentation curve was constructed and showed a typical kimchi curing curve having 2 stepwise pressure increasing pattern.