• Title/Summary/Keyword: a monitoring

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A Study on the Construction of Dynamic Recursive Control Model through a Machine State Monitoring (기계상태 Monitoring을 통한 동적 Recursive 제어모형 구축에 관한 연구)

  • 윤상원;윤석환;신용백
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.17 no.30
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    • pp.107-116
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    • 1994
  • This paper formulates a dynamic monitoring and control model with a machine state by quality variations in a single lot production system. A monitoring model is based on estimate of machine state obtained using control theory. The model studied in this paper has a great advance from a point of view the combination between quality control (Sampling, Control Chart) and automatic control theory, and can be extended in a several ways.

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Health Monitoring of High-rise Building with Fiber Optic Sensor (SOFO)

  • Mikami, Takao;Nishizawa, Takao
    • International Journal of High-Rise Buildings
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    • v.4 no.1
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    • pp.27-37
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    • 2015
  • Structural health monitoring is becoming more and more important in the domain of civil engineering as a proper mean to increase and maintain the safety, especially in the land of earthquakes like Japan. In many civil structures, the deformations are the most relevant parameter to be monitored. In this context, a monitoring technology based on the use of long-gage fiber optic deformation sensor, SOFO is being applied to a 33-floors tall building in Tokyo. Sensors were installed on the $2^{nd}$ floor's steel columns of the building on May 2005 in the early stage of the construction. The installed SOFO sensors were dynamic compatible ones which enable both static and dynamic measurements. The monitoring is to be performed during the whole lifespan of the building. During the construction, static deformations of the columns had been measured on a regular basis using a reading unit for static measurement and dynamic deformation measurements were occasionally conducted using a reading unit for dynamic measurement. The building was completed on August 2006. After the completion, static and dynamic deformation measurements have been continuing. This paper describes a health monitoring technology, SOFO system which is applicable to high-rise buildings and monitoring results of a 33-floors tall building in Tokyo from May 2005 to October 2010.

Study of the Validity Test on the Self-monitoring Scale for Primi-Gravida (초임부를 대상으로 한 자가검색도 척도의 타당도 비교)

  • Lee, Seon-Ah
    • Women's Health Nursing
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    • v.4 no.2
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    • pp.173-186
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    • 1998
  • In this study, both the literary survey as well as empirical research has been executed to test the validity of the scales that measure the construct of self-monitoring scale could not be classified into five factors as Snyder suggested. Many other scholars (Briggs, Cheek and Buss, 1980) suggested 3 different classifications which was accepted by Snyder and Gangestad (1986). John, Cheek and Klohnen (1996) claimed a two-factor classification. As has been discussed, factor analysis is used to prove convergent validity within the factor and discriminant validity between the factors. However, depending on the researchers, many variations in classification of the factors were found and a lack of content and discriminant validity was found in the previous research findings. It is also important to note that Snyder's self-monitoring scale, did not factor-load at over 30 for all 25 items, regardless of how many factors could be classified. According to findings of this study, the self-monitoring scale neither classified as five, three or two factors nor factor loaded as hypothesized. It is also clear that Snyder's self-monitoring scale lack convergent validity as the sub-factors of the scale fail to prove its uni-dimensionality. The A self-monitoring scale not only fail to overcome the problems of Snyder's self-monitoring scale but even lost the attractiveness of the self-monitoring scale. In this study, it was also found that the A self-monitoring scale was not classified as hypothesized in either in a two or three-factor classification. It is, of course, not desirable to use any scale that lacks convergent and discriminant validity even though it has been widely used but also has held a great deal of influence on the field of social psychology. To overcome the shortcomings of Snyder's self-monitoring scale, Lennox and Wolfe(1984) suggested 13 items. This study 1. was dedicated to test the validity and reliability of the scale, in which we found that the data presented in validity as the two factors were classified and loaded as expected. Reliability was also proven by checking Cronbach's alpha for each factor and for the total items. In addition, a confirmatory factor analysis was executed for the 13 items using LISREL 8.12 program to confirm convergent validity in a two-factor classification. The model was fitting and sound ; however, the self-monitoring scale was unfitted and not validated. Thus, it is recommended to use not the original or the abbreviated self-monitoring scale but the 13 items in future studies. It should also be noted that items 7 and 13 should be removed to obtain better uni-dimensionality for the 13 items. These items loaded at over .30, too high for the two factors in the test results of factor analysis. In addition, it is necessary to double-check the cause of two-hold loading at over .30 for the two factors. It could be a problem caused by data or by the scale itself. Therefore, additional studies should follow to better clarify this matter.

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Development of an environment field monitoring system to measure crop growth

  • Kim, Yeon-Soo;Kim, Du-Han;Chung, Sun-Ok;Choi, Chang-Hyun;Choi, Tae-Hyun;Kim, Yong-Joo
    • Korean Journal of Agricultural Science
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    • v.46 no.1
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    • pp.57-65
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    • 2019
  • The purpose of this study was to develop an environment field monitoring system to measure crop growth. The environment field monitoring system consisted of sensors, a data acquisition system, and GPS. The sensors used in the environment field monitoring system consisted of an ambient sensor, a soil sensor, and an intensity sensor. The temperature and humidity of the atmosphere were measured with the ambient sensor. The temperature, humidity, and EC of the soil were measured with the soil sensor. The data acquisition system was developed using the Arduino controller. The field monitoring data were collected before a rainy day, on a rainy day, and after the rainy day. The measured data using the environment field monitoring system were compared with the Daejeon regional meteorological office data. The correlation between the data from the environment field monitoring system and the data from the Daejeon regional meteorological office was analyzed for performance evaluation. The correlation of the temperature and humidity of the atmosphere was analyzed because the Daejeon regional meteorological office only provided data for the temperature and humidity of the atmosphere. The correlation coefficients were 0.86 and 0.90, respectively. The result showed a good correlation between the data from the environment field monitoring system and the data from the Daejeon regional meteorological office. Therefore, the developed system could be applied to monitoring the field environment of agricultural crops.

Development of a Web-Based Remote Monitoring System for Evaluating Degradation of Machine Tools Using ART2 (ART2 신경회로망을 이용한 공작기계의 웹기반 원격 성능저하 모니터링 시스템 개발)

  • Kim, Cho-Won;Choi, Kook-Jin;Jung, Sung-Hwan;Hong, Dae-Sun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.42-49
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    • 2009
  • This study proposes a web-based remote monitoring system for evaluating degradation of machine tools using ART2(Adaptive Resonance Theory 2) neural network. A number of studies on the monitoring of machine tools using neural networks have been reported. However, when normal condition is changed due to factors such as maintenance, tool change etc., or a new failure signal is generated, such algorithms need to be entirely retrained in order to accommodate the new signals. To cope with such problems, this study develops a remote monitoring system using ART2 in which new signals when required are simply added to the classes previously trained. This system can monitor degradation as well as failure of machine tools. To show the effectiveness of the proposed approach, the system is experimentally applied to monitoring a simulator similar to the main spindle of a machine tool, and the results show that the proposed system can be extended to monitoring of real industrial machine tools and equipment.

Full-scale bridge expansion joint monitoring using a real-time wireless network

  • Pierredens Fils;Shinae Jang;Daisy Ren;Jiachen Wang;Song Han;Ramesh Malla
    • Structural Monitoring and Maintenance
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    • v.9 no.4
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    • pp.359-371
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    • 2022
  • Bridges are critical to the civil engineering infrastructure network as they facilitate movement of people, the transportation of goods and services. Given the aging of bridge infrastructure, federal officials mandate visual inspections biennially to identify necessary repair actions which are time, cost, and labor-intensive. Additionally, the expansion joints of bridges are rarely monitored due to cost. However, expansion joints are critical as they absorb movement from thermal effects, loadings strains, impact, abutment settlement, and vehicle motion movement. Thus, the need to monitor bridge expansion joints efficiently, at a low cost, and wirelessly is desired. This paper addresses bridge joint monitoring needs to develop a cost-effective, real-time wireless system that can be validated in a full-scale bridge structure. To this end, a wireless expansion joint monitoring was developed using commercial-off-the-shelf (COTS) sensors. An in-service bridge was selected as a testbed to validate the performance of the developed system compared with traditional displacement sensor, LVDT, temperature and humidity sensors. The short-term monitoring campaign with the wireless sensor system with the internet protocol version 6 over the time slotted channel hopping mode of IEEE 802.15.4e (6TiSCH) network showed reliable results, providing high potential of the developed system for effective joint monitoring at a low cost.

A Study on the Correlation of Condition Monitoring Parameters of Functional Machine Failures. (기계시스템 파손에 따른 상태진단 파라미터의 상관관계 해석에 관한 연구)

  • 장래혁;강기홍;공호성;최동훈
    • Tribology and Lubricants
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    • v.18 no.4
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    • pp.285-290
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    • 2002
  • Integrated condition monitoring is required to monitor effectively the machine conditions since machine failures could not be monitored accurately by any single measurement parameter. Application of various condition monitoring techniques is therefore preferred in many cases in order to diagnosis the machine condition. However it inevitably requires lots of maintenance cost and sometimes it could be proved to over-maintenance unnecessarily. This could happen especially when one measurement parameter closely correlates to another. Therefore correlation analysis of various monitoring parameters has to be performed to improve the reliability of diagnosis. In this work, Pearson correlation coefficient was used to analyze the correlation between condition monitoring parameters of an over-loaded machine system where the vibration, wear and temperature were monitored simultaneously. The result showed that Pearson correlation coefficient could be regarded as a good measure for evaluating the availability of condition monitoring technology.

SEISMIC MONITORING IN SURFACE MINES

  • Ajay Kumar, L.;David Raj, D. Edwin;Renaldy, T. Amrith;Vinoth, S.
    • Tunnel and Underground Space
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    • v.19 no.3
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    • pp.174-180
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    • 2009
  • This paper gives a brief review of seismicity and seismic monitoring in surface mines. A summary of various researches related to seismicity is presented. Our research focuses on the understanding of seismicity and the application of analytical techniques to seismicity. Seismic monitoring plays an important role in the identification of potential failure planes and thereby predict potential failures. Much of the instrumentation used in our research is derived from earthquake monitoring systems. The major aspects in seismic monitoring are an instrumentation used, size of the network and data acquisition systems. Seismic monitoring in surface mines could be successfully applied to the improvement of safety standards in slope stability.

Structural performance monitoring of an urban footbridge

  • Xi, P.S.;Ye, X.W.;Jin, T.;Chen, B.
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.129-150
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    • 2018
  • This paper presents the structural performance monitoring of an urban footbridge located in Hangzhou, China. The structural health monitoring (SHM) system is designed and implemented for the footbridge to monitor the structural responses of the footbridge and to ensure the structural safety during the period of operation. The monitoring data of stress and displacement measured by the fiber Bragg grating (FBG)-based sensors installed at the critical locations are used to analyze and assess the operation performance of the footbridge. A linear regression method is applied to separate the temperature effect from the stress monitoring data measured by the FBG-based strain sensors. In addition, the static vertical displacement of the footbridge measured by the FBG-based hydrostatic level gauges are presented and compared with the dynamic displacement remotely measured by a machine vision-based measurement system. Based on the examination of the monitored stress and displacement data, the structural safety evaluation is executed in combination with the defined condition index.

A study on BEMS-linked Indoor Air Quality Monitoring Server using Industrial IoT

  • Park, Taejoon;Cha, Jaesang
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.65-69
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    • 2018
  • In this paper, we propose an interworking architecture for building indoor air quality monitoring server (BEMS) using IIoT (Industrial Internet of Things). The proposed monitoring server adopts IIoT-based standard protocol so that interaction with BEMS installed in existing buildings can be performed easily. It can effectively communicate with indoor air quality measurement sensor installed in the building based on IIoT, Indoor air quality monitoring is possible. We implemented a proposed monitoring server, and confirmed the availability and monitoring of data from sensors in the building.