• 한국공작기계학회논문집
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• 제13권5호
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• pp.118-123
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• 2004

The compressor has one of important roles in refrigeration cycle and it determines refrigeration efficiency and quality This paper aims to monitor rotary compressors for room air conditioners by using Acoustic Emission(AE) technique. The reliability of rotary compressors has been evaluated through visual inspection on them after long term test. This paper describes methods for acquisition and processing AE raw signal to monitor the state of rotary compressor. A detecting method of abnormal compressor in real time is suggested and special-purpose monitoring system which can be applied to automatic manufacturing line is developed using one-chip microprocessor at low cost.

• 대한의생명과학회지
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• 제11권3호
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• pp.301-305
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• 2005

MR spectroscopy of intracellularly located $^{133}Cs$ has been used to monitor the uptake of Gd-EOB-DTPA by the isolated rat liver. As shown by ${31}P$ spectroscopy, accumulation of $^{133}Cs$ ions in hepatocytes does not produce detectable effects on the metabolism. The hepatic internalization of Gd-EOB-DTPA was followed by the paramagnetic relaxation enhancement of the intracellular $^{133}Cs$ ions, and confirmed by parallel quantitations of Gd and Cs run by inductively coupled plasma analysis of liver samples and aliquots of perfusate. Two peaks are observed at -22.0 and -23.5 ppm, with respect to the line of the external reference arbitarily set to 0 ppm. Upon rinsing of the extracellular compartment with regular K-H free of CsCl, the high-field resonance disappears within 20min. The intracellular concentration was confirmed by ICP, which gives a $Cs^+$ content of $22.0\pm3.5mM$. The relaxation data significantly underestimate the Gd content, suggesting a potential compartmentation of $Cs^+$ and the contrast agent.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.507-513
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• 2000

Objective : The purpose of this study is to evaluate the vitality of the teeth in and adjacent to the mandibular fracture line according to variable conditions of fracture and to establish the protocol of treatment of fracture line teeth. Materials and Methods : The vitality of 97 teeth in fracture line and 104 teeth adjacent to fracture line of 52 patients were invested preoperatively. Of these, 66 teeth in fracture line and 72 teeth adjacent to fracture line were monitored at least 6 months after operation. An electric pulp tester was used to measure pulpal response. The relationships between the vitality of teeth in variable time(preoperation, immediate post-operation; within 1 week after operation, and 6 months after operation) and variable conditions of fracture(horizontal, vertical gap of fracture line, the number of fracture line)were evaluated statistically. Result : The vitality of fracture line teeth in the 6 months after operation statistically differed by the vertical gap of fracture line and the number of fracture line. The vitality of fracture line adjacent teeth in the immediate post-operation only statistically differed by the vertical gap of fracture line. There were statistically differences between preoperative EPT value and vitality of fracture line teeth on 6 months after operation. There were 5 cases of complications including periapical and periodontal abscess. Of these, only one tooth was extracted and the others were well treated with endodontic treatment and subgingival curettage. Conclusion : It is recommended to retain teeth and to monitor the vitality of teeth in and adjacent to fracture line, unless there is an absolute indication for extraction.

• 한국항공우주학회지
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• 제37권12호
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• pp.1238-1244
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• 2009

본 연구는 헬리콥터용 터보축엔진의 온라인 상태진단을 위해 퍼지-신경망 알고리즘을 제안하였고 GUI 형태의 SIMULINK프로그램으로 개발하였다. 진단 프로그램 개발을 위해 look-up 테이블 형식 기본 성능 모듈로 계산시간을 줄였고 실시간 성능 데이터를 획득하기위해 신호 생성 모듈을 사용하였다. 이 프로그램은 계측성능상태를 모니터링하기위한 온라인 상태모니터링 프로그램과 계측데이터와 퍼지를 이용한 정성적인 상태진단과 신경 회로망을 이용한 정량적인 상태진단으로 이루어진다. 제안된 온라인 진단 프로그램은 헬리콥터엔진의 상태모니터링에 적용 가능여부를 확인하기 위하여 터보샤프트 엔진을 대상으로 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1099-1104
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• 1993

The real time control system for FMS(Flexible Manufacturing System) is implemented at this paper. To achieve this goal, the Colored and Timed Petri-Net model is constructed and used to simulate the real time operation of FMS. Using the Colored and Timed Petri-Net model, evaluating any kind of FMS plant is possible. On-line shceduler, intelligent dispatcher, real time monitor and the simulation model of shop floor are contructed using LAN communication, relational database system in this paper. Finally, this real time control system is applied to the FMS/CIM center at Seoul National University.

• Nuclear Engineering and Technology
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• 제28권5호
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• pp.500-505
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• 1996

At the reference plant(Wolsong unit No. 1) a manual poison sampling system is provided to periodically sample gadolinium from each tank and analyze it in the laboratory to provide assurance that adequate poison concentration in each tank is maintained. The AECB required a continuous, on-line monitoring system. On Wolsong unit No. 2, process piping adapter and new instrument loops added to the Liquid Injection Shutdown System(LISS) which is part of SDS2. The new instrument loops continuously monitor SDS2 poison conductivity and initiate an alarm when the poison concentration is too low.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 춘계학술대회
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• pp.445-446
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• 2022

본 논문에서는, 선박의 접/이안 과정을 모니터링 할 수 있는 인공지능 기반의 시스템에서 항만 작업 준비 및 선석 스케줄링 효율성 향상을 위해 계선줄 인식을 통한 접/이안 시간을 인식 하고자 한다. 기설계된 인공지능 모델의 개선을 통해 입력 이미지에서 계선줄을 추출할 수 있고, 계선줄이 선석에 도달 또는 떨어지는 시점을 인식하여 정확한 선박의 접/이안 시간을 제공할 수 있다. 개발 모델은 실환경 데이터를 이용하여 계선줄 인식이 가능함을 결과를 통해 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.124-130
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• 2014

In highly reliable and durable systems, failures due to aging might result in catastrophes. Aging monitoring techniques to prevent catastrophes by predicting such a failure are required. This paper presents a scan-based on-line aging monitoring scheme which monitors aging during normal operation and gives an alarm if aging is detected so that the system users take action before a failure occurs. We illustrate our modified scan chain architecture and aging monitoring control method. Experimental results show our simulation results to verify the functions of the proposed scheme.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.168-173
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• 2002

In this paper, we introduce the hardware of the measuring system for on-line test and evaluation of high speed rail. It is composed of 6 DAMs(Data Aquisition modules), 2 monitoring modules and 1 main computer. Each of DAMs is connected many kinds of sensors, such as accelerometers, thermocouples, strain gauges, volt meters, current meter, odermeter, and measures the signals from sensors, saves it and displays it on the displayer. Two monitoring modules monitor the major signals transferred from DAMs. A main computer controls 4 DAMs(DAM1, DAM2, DAM31 and DAM32) and 2 monitoring modules and also monitors the major signals transferred from DAMs.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.1-10
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• 2018

Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.