• 한국정보통신학회논문지
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• 제3권2호
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• pp.273-280
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• 1999

본 논문에서는 아나로그 파형분석의 파형추적기술을 이용하여 전자기기의 고장진단을 용이하게 할 수 있는 회로분석 시스템을 설계하고 구현하였다. 회로분석기는 CMOS, MOS 회로와 같은 신기술 전자부품들을 간단하게 검사할 수 있는 개선된 능력을 가지며, 내장된 펄스 구동기를 사용하여 SCR, TRIAC 그리고 Optocoupler와 같은 게이트 구동소자들을 고장진단하게 한다. 회로분석기는 측정하고자 하는 부품 및 기판에 전원을 인가하지 않고 측정하도록 하여 측정하는 중에 발생 가능성 있는 일시적인 Short로 인한 회로의 추가적인 손상을 방지하고 반도체소자의 임피던스 상태를 분석하며 시스템 또는 PCB기판의 영구적인 고장을 일으키는 누액 또는 기판손상으로 인한 문제를 완벽하게 찾아낼 수 있었다. 이상이 의심되는 부품과 정상 부품간의 상호 비교할 수 있기 때문에 부품 식별 번호가 없거나 알아보기 힘든 부품의 고장진단에 이상적으로 응용할 수 있는 방안을 제시하도록 한다.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.120-131
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• 2016

The full results of troubleshooting process related to the flight control system of a tilt-rotor type UAV in the flight tests are described. Flight tests were conducted in helicopter, conversion, and airplane modes. The vehicle was flown using automatic functions, which include speed-hold, altitude-hold, heading-hold, guidance modes, as well as automatic take-off and landing. Many unexpected problems occurred during the envelope expansion tests which were mostly under those automatic functions. The anomalies in helicopter mode include vortex ring state (VRS), long delay in the automatic take-off, and the initial overshoot in the automatic landing. In contrast, the anomalies in conversion mode are untrimmed AOS oscillation and the calibration errors of the air data sensors. The problems of low damping in rotor speed and roll rate responses are found in airplane mode. Once all of the known problems had been solved, the vehicle in airplane mode gradually reached the maximum design speed of 440km/h at the operation altitude of 3km. This paper also presents a comprehensive detailing of the control systems of the tilt-rotor unmanned air vehicle (UAV).

• 약학회지
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• 제28권6호
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• pp.371-377
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• 1984

• 약학회지
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• 제28권6호
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• pp.379-383
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• 1984

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2000년도 제17회 학술발표회
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• pp.3-3
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• 2000

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2000년도 제17회 학술발표회
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• pp.4-4
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• 2000

• 한국지능시스템학회논문지
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• 제11권6호
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• pp.465-469
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• 2001

In injection molding short shot is one of the frequent and fatal defects. Experts of Injection molding usually adjust process conditions such as injection time, mold temperature, and melt temperature because it is most economic way in time and cost. However, it is difficult task to find appropriate process conditions for troubleshooting of short shot as injection molding process is a highly nonlinear system and process conditions are coupled. In this paper, a modular fuzzy neural network (MFNN) has been applied to injection molding process to shorten troubleshooting time of short shot. Based on melt temperature and fill time, a reasonable initial mo이 temperature is recommenced by the NFNN, and then the mold temperature is inputted to injection molding process. Depending on injection molding result, specifically the insufficient quantity of an injection molded part. and appropriate mold temperature is recommend repeatedly through the NFNN.

• 한국정밀공학회지
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• 제19권11호
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• pp.83-88
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• 2002

In order to predict the moldability of a injection molded part, a simulation of filling is needed. Short shot is one of the most frequent troubles encountered during injection molding process. The adjustment of process conditions is the most economic way to troubleshoot the problematic short shot in cost and time since the mold doesn't need to be modified at all. But it is difficult to adjust the process conditions appropriately in no times since it requires an empirical knowledge of injection molding. In this paper, the intelligent CAE system synergistically combines fuzzy-neural network (FNN) for heuristic knowledge with CAE programs for analytical knowledge. To evaluate the intelligent algorithms, a cellular phone flip has been chosen as a finite element model and filling analyses have been performed with a commercial CAE software. As the results, the intelligent CAE system drastically reduces the troubleshooting time of short shot in comparison with the experts' conventional methodology which is similar to the golden section search algorithm.

• 한국항공운항학회지
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• 제25권3호
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• pp.61-67
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• 2017

The Nose Landing Gear(NLG) of Rotary Wing Aircraft is an essential equipment in Landing System for pilot to perform a flight mission. It supports the fuselage at ground and absorbs the impact from the ground when landing, thereby, these functions sustain operational capability for pilot and crew. However, the A aircraft caused stick-slip behavior when it was stationed on the ground. Therefore, this paper summarizes pilot comment in operation which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.189-192
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• 2002

When a large scale system and its machinery have a trouble, an inexperienced personnel has a difficulty to find out a countermeasure and to understand the situation quickly. In this paper, a Online Guide Application using 3D Virtual Reality is proposed, and it will be used for operator to work out a countermeasure quickly and to see a trouble situation widely. This application shows possibility of minimizing effects of an incident by presenting effective troubleshooting process. moreover, this is expected to be applied to training program.