• Title, Summary, Keyword: monitoring

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Tool wear monitoring of end mill in slot machining of titanium alloy (티타늄 합금의 슬롯가공에서 엔드밀 공구마멸 감시)

  • 하건호;구세진;김정석;양순철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.101-104
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    • 1995
  • A acoustic emission (AE) sensor has been used to monitor tool were during milling process. The relation between tool wear and AE RMS (Root mean Square) signal was investigated experimentally. A avaliable monitoring index for monitoring toolwear was newly extracted form AE RMS. And on-line monitoring program was developed. The proposed monitoring system has verified experimentally by roughing end milling titanium alloy with TIN coated HSS tool.

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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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    • 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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On-Line Condition Monitoring of Electrical Equipment Using Temperature Sensor (온도센서를 이용한 전력설비의 온라인 상태 감시)

  • Choi, Yong-Sung;Kim, Sun- Jae;Kim, Yeong-Min;Song, Hwao-Kee;Lee, Kyung-Sup
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.2
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    • pp.202-208
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    • 2008
  • Condition monitoring technologies allow achieving this goal by minimizing downtime through the integrated planning and scheduling of repairs indicated by condition monitoring techniques. Thermal runaways induced by conduction problems deteriorate insulating material and cause disruptive dielectric discharges resulting in arcing faults. Therefore, having the ability to directly measure the temperature of the contacts while in service will provide more information to determine the true condition of the equipment. It allows connective measures to be taken to prevent upcoming failure. Continuous temperature monitoring and event recording provides information on the energized equipment's response to normal and emergency conditions. On-line temperature monitoring helps to coordinate equipment specifications and ratings, determine the real limits of the monitored equipment and optimize facility operations. Using wireless technique eliminates any need for special cables and wires with lower installation costs if compared to other types of online condition monitoring equipment. In addition, wireless temperature monitoring works well under difficult conditions in strategically important locations. Wireless technology for on -line condition monitoring of energized equipment is applicable both as stand alone system and with an interface for power quality monitoring system. The paper presents the results of wireless temperature monitoring: of electrical equipment at a power plant.

A Case Study on GNSS Based Deflection and Dynamic Characteristics Monitoring Analysis for SeoHae Bridge

  • Lee, Jae Kang;Kim, Jung Ok
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.5
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    • pp.389-404
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    • 2017
  • The main purpose of this presented investigation is to build up the BHMS based on GNSS. This proposed monitoring system can conduct the deflection and dynamic characteristics analysis by using only GNSS positioning solution. The general bridge monitoring system being operated recently is composed of a combination of various sensors that are able to conduct deflection monitoring and dynamic characteristics monitoring analysis at the same time. However, GNSS based BHMS has the unique procedure in terms of data analysis. In the other words, GNSS positioning solution is firstly applied to deflection monitoring analysis then, this deflection analysis can be sequentially reflected in the dynamic characteristics. Unfortunately, the adjustment result of GNSS positioning solution estimated through various options and conditions and the process of monitoring analysis has not been fulfilled systematically. This means that different results or analysis value are presented according to the methodology and officers. Most of researches have been focusing on deflection monitoring analysis and some investigation regarding to dynamic characteristics is recently introduced. Moreover, it is not still reported the systematic investigation with regards to proper filtering and analysis methodology. This study was carried out based on a large amount of data, from this, various variables not reported yet are actively considered. Therefore, specific software for both monitoring analysis have been developed.

Risk identification, assessment and monitoring design of high cutting loess slope in heavy haul railway

  • Zhang, Qian;Gao, Yang;Zhang, Hai-xia;Xu, Fei;Li, Feng
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.67-78
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    • 2018
  • The stability of cutting slope influences the safety of railway operation, and how to identify the stability of the slope quickly and determine the rational monitoring plan is a pressing problem at present. In this study, the attribute recognition model of risk assessment for high cutting slope stability in the heavy haul railway is established based on attribute mathematics theory, followed by the consequent monitoring scheme design. Firstly, based on comprehensive analysis on the risk factors of heavy haul railway loess slope, collapsibility, tectonic feature, slope shape, rainfall, vegetation conditions, train speed are selected as the indexes of the risk assessment, and the grading criteria of each index is established. Meanwhile, the weights of the assessment indexes are determined by AHP judgment matrix. Secondly, The attribute measurement functions are given to compute attribute measurement of single index and synthetic attribute, and the attribute recognition model was used to assess the risk of a typical heavy haul railway loess slope, Finally, according to the risk assessment results, the monitoring content and method of this loess slope were determined to avoid geological disasters and ensure the security of the railway infrastructure. This attribute identification- risk assessment- monitoring design mode could provide an effective way for the risk assessment and control of heavy haul railway in the loess plateau.

Assessment of a smartphone-based monitoring system and its application

  • Ahn, Hoyong;Choi, Chuluong;Yu, Yeon
    • Korean Journal of Remote Sensing
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    • v.30 no.3
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    • pp.383-397
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    • 2014
  • Information technology advances are allowing conventional surveillance systems to be combined with mobile communication technologies, creating ubiquitous monitoring systems. This paper proposes monitoring system that uses smart camera technology. We discuss the dependence of interior orientation parameters on calibration target sheets and compare the accuracy of a three-dimensional monitoring system with camera location calculated by space resectioning using a Digital Surface Model (DSM) generated from stereo images. A monitoring housing is designed to protect a camera from various weather conditions and to provide the camera for power generated from solar panel. A smart camera is installed in the monitoring housing. The smart camera is operated and controlled through an Android application. At last the accuracy of a three-dimensional monitoring system is evaluated using a DSM. The proposed system was then tested against a DSM created from ground control points determined by Global Positioning Systems (GPSs) and light detection and ranging data. The standard deviation of the differences between DSMs are less than 0.12 m. Therefore the monitoring system is appropriate for extracting the information of objects' position and deformation as well as monitoring them. Through incorporation of components, such as camera housing, a solar power supply, the smart camera the system can be used as a ubiquitous monitoring system.

Literature Review of Machine Condition Monitoring with Oil Sensors -Types of Sensors and Their Functions (윤활유 분석 센서를 통한 기계상태진단의 문헌적 고찰 (윤활유 센서의 종류와 기능))

  • Hong, Sung-Ho
    • Tribology and Lubricants
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    • v.36 no.6
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    • pp.297-306
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    • 2020
  • This paper reviews studies on the types and functions of oil sensors used for machine condition monitoring. Machine condition monitoring is essential for maintaining the reliability of machines and can help avoid catastrophic failures while ensuring the safety and longevity of operation. Machine condition monitoring involves several components, such as compliance monitoring, structural monitoring, thermography, non-destructive testing, and noise and vibration monitoring. Real-time monitoring with oil analysis is also utilized in various industries, such as manufacturing, aerospace, and power plants. The three main methods of oil analysis are off-line, in-line, and on-line techniques. The on-line method is the most popular among these three because it reduces human error during oil sampling, prevents incipient machine failure, reduces the total maintenance cost, and does not need complicated setup or skilled analysts. This method has two advantages over the other two monitoring methods. First, fault conditions can be noticed at the early stages via detection of wear particles using wear particle sensors; therefore, it provides early warning in the failure process. Second, it is convenient and effective for diagnosing data regardless of the measurement time. Real-time condition monitoring with oil analysis uses various oil sensors to diagnose the machine and oil statuses; further, integrated oil sensors can be used to measure several properties simultaneously.

Insight Sources and Influence of Yellow-sand Events in Spring 2003

  • Zhuanshi He;Kim, Young J.;Kim, Jeong E.;K.O. Ogunjobi;Seong Y. Ryu;Kim, Kyung W.;Lee, Kwon H.;Park, Sung C.;Lee, Chul K.;Park, han S.;Yong M. Noh;Jin S. Jung;Kim, Min J.;Hyun R. Jung
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.281-282
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    • 2003
  • The significant spring-time phenomenon known as the "Yellow Sand" influences not only regional but also global climate. It′s believed that frequency of yellow-sand events has increased in recent years. To investigate the possible factors inducing these special strong weather phenomenon and its impacts on meteorological elements, intensive sampling will be conducted by ADEMRC/KJIST from March to May 2003. Lagrangian trajectory (forward and backward), cluster analysis, factor analysis and satellite remote sense (SRS) techniques will be employed to inspect the mechanisms of yellow-sand. (omitted)

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On-line Monitoring and Diagnostics for Distribution Panel System (배전반 시스템의 온라인 감시 및 진단)

  • Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.106-110
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    • 2008
  • Continuous on-line temperature monitoring allows corrective measures to be taken to prevent upcoming failure. Continuous temperature monitoring and event recording provides information on the energized equipment's response to normal and emergency conditions. On-line temperature monitoring helps to coordinate equipment specifications and ratings, determine the real limits of the monitored equipment and optimize facility operations. Using wireless technique eliminates any need for special cables and wires with lower installation costs if compared to other types of online condition monitoring equipment. In addition, wireless temperature monitoring works well under difficult conditions in strategically important locations. Wireless technology for on-line condition monitoring of energized equipment is applicable both as standalone system and with an interface with power quality monitoring system.

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Esophageal pH and Combined Impedance-pH Monitoring in Children

  • Shin, Myung Seok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.17 no.1
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    • pp.13-22
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    • 2014
  • Esophageal pH monitoring is considered the gold standard for the diagnosis of gastroesophageal reflux disease because of the normal ranges across the pediatric age range. However, this method can only detect acid reflux. Multichannel intraluminal impedance-pH (MII-pH) monitoring has recently been used for the detection of bolus reflux in infants and children. This method allows for the detection of liquid, gas or mixed reflux in addition to acid, weakly acidic or weakly alkaline reflux. MII-pH monitoring can record the direction of flow and the height of reflux, which are useful parameters to identify an association between symptoms and reflux. However, the technique is limited by its high cost and the lack of normative data of MII-pH in the pediatric population. Despite certain limitations, MII-pH monitoring will become more common and gradually replace pH monitoring in the future, because pH monitoring is part of MII-pH.