• 전기학회논문지
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• 제61권11호
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• pp.1732-1736
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• 2012

To increase speed up of train, in the field of catenary system, it is necessary to develop of new monitoring methods for dynamic interaction between pantograph and contact wire. Also, there is a need to develop technologies that constantly measure are from various railway structure such as uplift of contact wire, vibration of catenary, dynamic strain of contact line in tunnel. In this paper condition monitoring systems for dynamic performance of catenary systems in tunnel were proposed. An advanced method and results of field tests using high speed camera for monitoring of vertical upward movement of the grooved contact wire due to the force produced from the pantograph were presented. The proposed uplift measurement system of contact wire is expected to enhance precision of current collection quality performance assessment methods at high-speed lines.

• 한국철도학회논문집
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• 제6권4호
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• pp.232-238
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• 2003

A health monitoring system becomes a very useful tool to obtain information on long term behavior of the important railway structures such as very long span and special type bridges. It can be also used to give a warning signal to the maintenance engineer when the structure shows abnormal behavior. However, due to long term use and temperature changes, the health monitoring system needs to be calibrated periodically. In this study, calibration and gauge factor readjustment process made for the health monitoring system installed in the railroad bridges and tunnel are reviewed and a few findings are updated. Future work will be concentrated on the long-term analysis of the measurement data and on the database structures so that the assessment of the structure is possible

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.989-995
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• 2010

This paper is focused on a simplified measurement of rail irregularity by some axle-box accelerometers for high-speed rail condition monitoring with in-service high-speed trains. Generally, the rail condition monitoring has been done by a special railway inspection vehicle with a 10m versine method. But, the monitoring method needs some expensive measurement system, and have been performed only at night due to its speed limit. In this research, a simplified measurement of rail irregularity using axle-box accelerometers is proposed to monitor the rail condition with in-service high-speed trains. The acceleration is measured by using two accelerometers on a axle-box, and stored in an on-board data acquisition system. The displacement is estimated from the acceleration data by a combination of Kalman filter and the frequency selective filter. The estimated results are compared with the measurement from a laser rail inspection system which is near the axle-box. From the comparison, the proposed method shows promise as a tool for the simplified measurement of rail irregularity at high-speed.

• 한국산업보건학회지
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• 제27권2호
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• pp.87-96
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• 2017

Objectives: Improvement of the reliability of work environment measurement results is one of the principal subjects to be resolved in the field of industrial hygiene. Thus, this study was conducted in order to review domestic programs for enhancing the reliability of work environment measurement results and propose a more efficient management plan for workplace monitoring. Materials and Methods: The current domestic programs reviewed in this study are the quality control system and evaluation system for industrial hygiene laboratories, the reliability system accompanied by KOSHA (the Korea Occupational Safety and Health Agency), the system of permissible exposure limits and observed inspection system for permissible exposure limits. Their contents and data were analyzed by reviewing articles, reports, and guidelines related to reliability improvement for work environment measurement results. Results: As a result of the literature review, all the domestic programs investigated in this study had both merits and demerits in terms of considering the reliability of work environment measurement results. In particular, the fact that preliminary notification is provided to the head of a workplace before implementation would be an obstacle for elevating the reliability of work environment measurement results. Conclusions: Based on the review results obtained from this study, it is proposed that on-site measurement without preliminary notification should be considered for a more efficient inspection system that would enhance the reliability of workplace monitoring.

• 한국가시화정보학회지
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• 제20권2호
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• pp.86-92
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• 2022

Pipe failure due to thermal fatigue and environmental regulations are increasing the importance of pipe monitoring systems in industrial plants. Since most pipe monitoring systems are focus on external crack inspected, it is necessary to temperature and concentration measuring monitoring system inside the pipe. These systems have spatial uncertainty due to sample inspection by one-point measurement. In addition, real-time measurement is not possible due to the limitation of time delay due to contact measurement. In this study, CT-TDLAS (Computed tomography-Tunable diode laser absorption spectroscopy) apply to overcome the limitations of existing methods. Lasers exhibiting an absorption response at a wavelength of 1395 nm were arranged in a lattice pattern on measuring cell. It showed that the inside of the pipe changed to an unstable combustion state over time.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.122-122
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• 2017

Recently, environmental problems have become an area of growing interests. In-situ monitoring of water quality is fundamental to most environmental applications. The accurate measurement of nitrate concentrations is fundamental to understanding biogeochemistry in aquatic ecosystems. Several studies have reported that one of the most feasible methods to measure nitrate concentration is the use of Ion Selective-electrodes (ISEs). The ISE application to water monitoring has several advantages, such as direct measurement methodology, high sensitivity, wide measurement range, low cost, and portability. However, the ISE methods may yield inconsistent results where there was a difference in temperature between the calibration and measurement solutions, which is associated with the temperature dependence of ionic activity coefficients in solution. In this study, to investigate the potential of using the combination of a temperature sensor and nitrate ISEs for minimizing the effect of temperature on real-time nitrate sensing in natural water, a prototype of on-site water monitoring system was built, mainly consisting of a sensor chamber, an array of 3 ISEs, an waterproof temperature sensor, an automatic sampling system, and an arduino MCU board. The analog signals of ISEs were obtained using the second-order Sallen-key filter for performing voltage following, differential amplification, and low pass filtering. The performance test of the developed water nitrate sensing system was conducted in a monitoring station of drinking water located in Jeongseon, Kangwon. A temperature compensation method based on two-point normalization was proposed, which incorporated the determination of temperature coefficient values using regression equations relating solution temperature and electrode signal determined in our previous studies.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.21-24
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• 2009

This study deals with the application of USN wireless inclinometer sensor for earth retaining structure safety measurement, The application of wireless inclinometer sensor has great advantage about real-time monitoring of earth retaining structure, It allows a construction manager to monitor movement data from anywhere connected through internet during the process of excavation for substructures of buildings, To validate the applicability of the wireless inclinometer sensor. laboratory and field tests have been performed, The results have shown that the measured values of wireless inclinometer sensor represent the behavior of H-pile well, Both convenience of sensor installation and real-time monitoring of earth retaining structure are confirmed, The proposed wireless measurement system provides a good basis for exact measurement of temporary substructures, More measurements and application are expected for the other excavation sites with various conditions.

• 한국지진공학회논문집
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• 제10권6호
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• pp.9-18
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• 2006

영종대교에 설치된 교량 모니터링 시스템의 구성특징을 살펴보고 이로부터 계측, 수집된 각 신호들의 특성을 조사 분석하였다. 3차원 자정식 현수교인 영종대교에 설치, 운영되는 모니터링 시스템의 구성은 센서-현장하드웨어-계측서버-관리자로 연결되는 자동화된 시스템으로써 개통 이후부터 교량의 거동 및 하중효과를 대변하는 물리량을 측정하고 있다. 이 논문에서는 시스템의 구성 및 측정항목에 대한 소개와 온도변화에 의한 시그널에의 영향을 감시 할 수 있는 알고리즘의 개발과정을 언급한다. 또한, 행어 케이블의 장력측정 방법의 일환으로 길이가 짧고 장력이 큰 케이블에 대해 정적으로 장력산정이 가능한 장치 및 알고리즘의 개발에 대해 소개한다. 특히 이 교량의 공용중에 이루어진 철도통행을 위한 설비의 추가로 교량 구조계의 변화를 계측 신호를 바탕으로 분석, 제시하였다. 이러한 각종 계측 및 모니터링 결과는 향후 교량의 상태판정의 기본자료로 활용되어 효율적 유지관리를 가능하게 할 것으로 기대된다.

• 한국인터넷방송통신학회논문지
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• 제18권4호
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• pp.161-168
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• 2018

고혈압은 현대 주요 성인병이며 기존의 혈압계로는 실시간 혈압 측정 및 원격 모니터링이 어렵다. 그러나 실시간 혈압 모니터링 u-헬스케어 시스템은 효과적인 건강관리가 가능하도록 해준다. 실시간 혈압 모니터링을 위해 본 논문에서는 손목형 혈압계, 스마트폰 및 u-헬스케어 서버로 구성된 실시간 혈압 모니터링 u-헬스케어 시스템의 구조를 제시한다. 그리고 손목형 혈압계의 하드웨어 설계를 위한 주요 핵심 기능인 맥파검출 아날로그 회로 구성과 손목형 혈압계를 구성하는 디지털 하드웨어 구성을 제시한다. 또한 이들 하드웨어 시스템을 동작시키는 소프트웨어 개발을 위한 UML 분석방법과 소프트웨어 설계를 위한 플로우차트와 화면 설계를 보여준다. 따라서 본 논문에서 제시한 설계방법은 실시간 모니터링 u-헬스케어 시스템 구현에 매유 유용하게 활용될 수 있을 것으로 기대된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1382-1385
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• 2007

In this paper, we study about the measuring algorithm that can implement Structural Health Monitoring (SHM) more efficiently by two measurement methods using smart sensor. Through the impedance measurement method, the damage condition of structures on wide area is monitored first, and then it changes the mode to guided wave measurement mode by mode switching algorithm when impedance measurement mode detects abnormal signals. Efficient handling of the real-time data would be available by analyzing location and shape of damage through guided wave measurement.