• Title/Summary/Keyword: condition monitoring.

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Evaluation Technique of Importance of Monitoring Systems for Earth and Rockfill Dam Safety (필댐 안전관리를 위한 계측기 중요도의 평가기법)

  • Lee, Jong-Wook;Kim, Jae-Hong;Oh, Byung-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.874-882
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    • 2009
  • Continuous monitoring of dam performance is essential to earth and rockfill dams safety because it has to be guaranteed for safety during construction period of course and from initial impounding to a long term maintenance period of dam. Among the 31 dams managed by Kwater at present, the proportion of dams being over 20 years after completion of construction is 42% and it is estimated that the loss rate of monitoring devices will be increase as times. Monitoring devices would be impossible to repair since those are mostly installed in the dam body and foundation. If repairing of monitoring devices is possible, the expenditure will be expensive. Therefore reasonable decision making for abandonment, repair and alternation for loss of monitoring devices would be needed through the establishment of key instrument for earth and rockfill dam safety. In this study the process of monitoring for safety were modeled by failure modes of dams, adverse conditions related to failure mode, indicators of adverse condition and monitoring devices The relationship between failure mode and monitoring devices were systematically analyzed and established and evaluation technique for qualifying the importance of monitoring devices were presented.

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Development of PVDF sensor and system to detect breathing sounds during deep sedation (진정 마취 시 호흡음 검출을 위한 PVDF 센서 및 시스템 개발)

  • Lee, Seung-Hwan;Li, Xiong;Im, Jae-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.153-159
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    • 2019
  • Respiration is one of the important vital signs to determine the condition of the patient. Especially during deep sedation, since the patient's apnea and hypopnea are difficult to detect without continuous monitoring, there is a need for a continuous respiration monitoring method that can accurately and simply determine the patient's respiratory condition. Currently, respiration monitoring methods using various devices have been developed, but these methods have not only late response time but also low reliability at the clinical stage. In this study, attachable sensor using PVDF(polyvinylidene fluoride) film and a monitoring device which could detect abnormal symptoms of breathing in early stage during deep sedation. The results of this study can be used in various medical fields including not only in the area of remote monitoring for respiration related sleep monitoring but also in routine monitoring during deep sedation.

신경망 모델을 이용한 밀링공구의 이상진단에관한 연구

  • 이상석;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.04b
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    • pp.71-75
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    • 1993
  • The application of artificial neural network forcondition monitoring and diagnosis of milling tools was introduced. To detect the conditions of milling tools, the monitoring wywtem consists of three phases: "preparation phase", "learning phase", "production phase". The conditions of milling tools were categorized into the three states. "normal", "warning", "abnormal". The dectection of tool condition, in this paper, could be successfully performed by monitoring the variation of power spectrum on Y dirctional cutting force.

Development of process monitoring system in ELID grinding (ELID 연삭에서 가공 상태 감시 시스템 개발)

  • 서영호;김화영;안중환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.599-602
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    • 2000
  • A new dressing technique with utilizes electrolytic phenomenon for realizing effective mirror surface grindings with metal bonded super-abrasive wheels is called “Electrolytic In-process Dressing Grinding”. This technique enabled metal bonded micro-grain wheels, such as micro-grain cast iron fiber bonded wheels, to be used for mirror surface finish processes effectively. But this technique requires a lot of knowledge and experience to perform. And the condition of dressing is variable according to the time. Therefore adaptation of Monitoring and Control technique is needed.

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Load Test and Remote Monitoring of P.C. Box Girder Bridge (P.C. BOX 교량의 재하시험 및 원격계측 유지관리 시스템)

  • Lee, Sung-Woo;Doobyong Bae;Lee, Sun-Goo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.122-131
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    • 1995
  • Load test for newly introduced precast segmental bridge is carried out to experimentally evaluate load carrying capacity, Analysis accompanied with the test is also performed and the results are used in the evaluation. In addition to initial evaluation of the bridge by load test, remote dynamic monitoring system to perform realtime assessment of the bridge condition is also under development. In this paper the procedure and results of load test and evaluation are presented along with introduction of dynamic monitoring system.

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The Development of the Condition Monitoring Equipment for distribution Facilities by using the UHF Partial Discharge Sensors (UHF PD 센서를 이용한 배전기기 상태감시장치 개발)

  • Cho, Yong-Jun;Hwang, Chul-Min;Kim, Young-Noh;Choi, Jae-Ok;Song, Il-Keun;Lee, Byung-Sung
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.406-407
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    • 2008
  • This paper is analyzed the internal type UHF partial Discharge sensors and Condition Monitoring Module that be able to monitor the condition of the distribution facilities. It set the PD cell on the inside of 22.9kV load switchgear and then it executed Partial Discharge test. it introduced the result of the test.

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Basic research for Health Monitoring Technique with PZT Patches (압전소자를 이용한 손상계측기술에 관한 기초연구)

  • Ha, Nam;Chae, Kwan-Suk;Hong, Dong-Pyo;Chae, Hee-Chang
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.870-874
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    • 2004
  • This work presents a study on development of a practical and quantitative technique for assessment of the structural health condition by Piezoelectric impedance-based technique associated with longitudinal wave propagation method. The bolt fastening condition is adjusted by torque wrench. In order to estimate the damage condition numerically, three damage indices, impedance peak frequency shift ${\Delta}F$, peak amplitude ratio $\delta$ and quality factor ratio $\gamma$, are proposed in this paper. Furthermore, an assessment method is described for estimation of the damage by using these three damage indices.

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An Expert System Using Diagnostic Parameters for Machine tool Condition Monitioring (공작기계 상태감시용 진단파라미터 전문가 시스템)

  • Shin, Dong-Soo;Chung, Sung-Chong
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.10
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    • pp.112-122
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    • 1996
  • In order to monitior machine tool condition and diagnose alarm states due to electrical and mechanical faults, and expert system using diagnostic parameters of NC machine tools was developed. A model-based knowledge base was constructed via searching and comparing procedures of diagnostic parameters and state parameters of the machine tool. Diagnostic monitoring results generate through a successive type inference engine were graphically displayed on the screen of the console. The validity and reliability of the expert system was rcrified on a vertical machining center equipped with FANUC OMC through a series of experiments.

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