• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.53-62
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• 2007

Recently, for the stabilization estimation of structures, many automatic measuring instruments with expensiveness and high accuracy have been developed and utilized. However, the existing manual measuring systems are almost impossible to measure the real-time for the whole surface of large-scale structures and an automatic measuring system has disadvantages with demanding enormous expense. In this study, 3D digital visual monitoring system was developed by using digital photogrammetry technique. To confirm application of developed system, it was applied to the measurement of the wall displacement of concrete surface and displacement measurement of reinforced-soil wall block. Then, the result of the test was compared with measuring value of total station. Based on the results of the comparison, the application of visual monitoring system was evaluated. The results show that the developed visual monitoring system could be available in displacement measure of structures.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.2
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• pp.195-201
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• 2012

According to many customers' requests, optical measurement module (OMM) applications using automatic measuring devices to measure the machined part rapidly on a machine tool have increased steeply. Touch trigger probes are being used for job setup and feature inspection as automatic measuring devices, and this makes quality checking and machining compensation possible. Therefore, in this study, the use of touch trigger probes for accurate measurement of the machined part has been studied and a macro program for a hole measuring cycle has been developed. This hole is the most common feature to be measured, but conventional methods are still not free from measuring error. In addition, the eccentricity change of the least square circle was simulated according to the roundness error in a hole measurement. To evaluate the reliability of this study, the developed hole-measuring program was executed to measure the hole plate on the machine and verify the roundness error in the eccentricity simulation result.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.481-486
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• 2019

Smart Factory requires real-time monitoring and analysis of all process processes for optimal production environment. Monitoring system for data collection from various sensors is necessary to make all production processes automatic. By storing and analyzing the collected data, we can check whether there are any signs of abnormalities in any machine or equipment. Thus, in this paper, an integrated monitoring system for smart factory incorporating a working environment monitoring system and an automatic storage system of measurement values was implemented. By using the automatic storage system of measurement values, it is possible to carry out reliable inspection in any place without misentry. Also, through working environment monitoring system using LoRa, production environments such as temperature, humidity and atmospheric pressure can be monitored in real time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.233-235
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• 2022

43차 산업혁명이 도래함에 따라 해운분야에도 자동화 및 무인화 기술을 접목한 안정성과 효율성을 향상시키기 위한 기술개발이 진행중이다. 그중 선박의 신속하고 안전한 이/접안을 돕도록 고안된 자동계류시스템은 선박의 식별 정보와 융합센서로부터 다양한 정보를 수집해 인력의 개입이 최소화하거나 무인화할 수 있으며, 이는 계류 라인을 이용한 기존 방법 대비 발생하는 위험 요소를 줄이고 효율적인 도선 지원이 가능하게 한다. 본 연구팀은 기초단계 연구로서 자율 운항 선박 구현을 위한 자동 계류 시스템 개념 설계를 제시한다. 연구내용은 크게 자동 계류시스템의 하드웨어 설계, 제어 및 운용 프로세스 설계, 선체 계측 기술 개발, 운동변위/계류력 산정 수치모델 개발, 항만 내 운영환경 및 시나리오 분석으로 분류할 수 있으며 본 발표에서는 연구현황과 추후 진행 방향에 대해 다루도록 한다.

• Tunnel and Underground Space
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• v.15 no.1 s.54
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• pp.1-8
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• 2005

Measurement of convergence was/is carried out manually throughout the world for tunnels under construction. However, manual method has certain limitations in terms of applicability for the tunnels in operation. This paper describes state of the art of convergence monitoring systems which are available for measuring displacement of existing tunnels. These technologies are analyzed as follows: 1 The Sofo system using the fiber optic sensors has been applied to the stress measurement of the tunnel lining. It has not yet been used for the monitoring of tunnel convergence because of its cost and reliability 2. A TPMS(Tunnel Profile Monitoring System) using tilt sensors and displacement sensors is used for the convergence monitoring of highway tunnels, subway tunnels and underground ducts. 3. A BCS(Bassett Convergence System) using a pair of tilt sensors can be used for the convergence monitoring of tunnels, however the accuracy of the measurement has to be improved because it uses AC input voltage during data acquisition. The system has to be validated before it can be applied to the tunnels in operation. Convergence monitoring systems using TPMS and/or BCS are recommended to be evaluated and improved by a series or tests in tunnels under construction in order to be applied to the main measuring section and the tunnels in operation.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.116-124
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• 2023

As the flood damage on small streams increase due to the increase in frequency of extreme climate events, the need to measure hydraulic data of them has increased for disaster risk management. National Disaster Management Institute, Ministry of Interior and Safety develops CADMT, a CCTV-based automatic discharge measurement technology, and operates pilot small streams to verify its performance and develop disaster risk management technology. The research selects two small streams such as the Neungmac and the Jungsunpil streams to develop the Nomograph by using the 4-Parameter Logistic method using only the observed rainfall data from the Automatic Weather System operated by the Korea Meteorological Agency closest to the small streams and discharge data collected by using the CADMT. To evaluate developed Nomograph, the research forecasts floods discharges in each small stream and compares the result with the observed discharges. As a result of the evaluations, the forecasted value is found to represent the observed value well, so if more accurate observed data are collected and the Nomograph based on it is developed in the future, the high-accuracy flood prediction and warning will be possible.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.164-171
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• 2019

Focusing on the bridge facilities, which occupy the largest proportion among SOC public facilities in Korea, it is possible to reduce the cost compared to existing wired measurement systems or wireless measurement systems developed by domestic telecommunications companies, and to increase the technical perfection to be applied to many bridges. We developed a wireless measurement system for bridges. Using LoRa, one of the unlicensed LPWAN technologies, we have developed an optimized MEMS-based LoRa smart sensor node considering the domestic ISM band and the existing wired sensor LoRa DAQ sensor node that can communicate with the LoRa network. Application server was developed for the test bed performance verification and efficient management of the developed sensor node.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.32-40
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• 1989

Dynamic ship positioning(DP) system is used to keep the position and heading of a ship, or a floating platform, above a pre-selected site on the seabed by using thrusters. This paper presents a control system based on filtering technique and optimal control theory. The planar motions of a vessel are assumed to consist of low frequency(LF) component and high frequency(HF) one. The former is mainly due to thrusters, current, wind and second order wave forces, while the latter is mainly due to first order oscillatory component of the wave force. Furthermore position measurement signals include the noise. By means of self-tuning filter and Kalman filter techniques, LF motion estimates and HF ones are seperately achieved from the position measurements of the vessel. The estimated LF motions are used as input to the feedback loops. The total thruster power is minimized using the Linear Quadratic Gaussian control theory. The performance of the vessel with the DP system is investigated by computer simulation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.25-25
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• 2022

하천의 개발 및 보전 계획을 수립하는 데에 있어 자연하천의 부유사량 및 총유사량을 계측하는 것은 매우 중요하다. 우리나라에서는 매년 국내 자연하천을 대상으로 부유사량을 실측하고 실측 부유사량을 바탕으로 수정 아인슈타인 방법을 적용해 총유사량을 산정하고 있으나 이 또한 홍수기에 국한되어 있다. 가장 일반적인 유사량 계측 방법인 시료 채집에 의한 방법은 많은 노력과 비용을 수반하기 때문에 유사량 관측소와 관측 빈도를 늘릴 수 없는 실정이다. 최근에는 ADCP 음파 신호의 후방산란도가 부유사 농도에 따라 증가한다는 성질을 이용해 부유사 농도 계측에 ADCP를 이용하고자 하는 노력이 계속되고 있다. 이러한 특성을 이용해 본 연구에서는 전라남도 나주시에 위치한 남평교 자동유량관측소에 설치된 횡방향 ADCP (H-ADCP)를 대상으로 서포트 벡터 회귀(SVR)를 적용한 실시간 유사량 모니터링 모형을 제안하였다. 여기서 제시하는 유사량산정 모형은 크게 유량과 초음파 산란도를 입력 변수로 해 부유사 농도를 산정하는 서포트 벡터 회귀 모형과 첫 번째 모형으로부터 산정된 부유사 농도와 흐름 정보를 이용해 총유사량을 산정하는 모형으로 구성되어 있다. 개발된 SVR 부유사량 및 총유사량 산정 모형의 정확도가 결정계수(R²) 기준으로 각각 0.82, 0.90 으로 나타났다. 주목할 점은, 본 연구에서 제시하는 SVR 모형을 이용해 멱함수 기반 유사량 관계식으로는 예측할 수 없는 유사량의 이력현상을 재현해낼 수 있다는 것이다. 본 연구에서 제시하는 H-ADCP 기반 총유사량 모니터링 방법은 기존 자동 유량 관측소 시설을 그대로 이용할 수 있다는 장점이 있다. 따라서 실무 적용 시 낮은 추가비용으로 양질의 유사량 모니터링이 가능할 것으로 기대된다.

• Journal of the KSME
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• v.18 no.1
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• pp.42-46
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• 1978

컴퓨터가 기계공업에 많이 활용이 되고있다. 더구나 컴퓨터의 출현으로 인해 종래의 기계공업의 모습이 많이 달라졌다고 하겠다. 그것들중 여기서는 CAD/CMA system에 대한 소개를 하였는데, 이 system을 완성하는데엔 충분한 data 에 의한 system design이 필요함은 ,물론이다. 최적화된 system design에 의해 각공정의 제조 system이 구성 되는데 이 컴퓨터에 의한 자등생산 system은 실질적으로 생산이 효율을 높이기 위해서는 자동설계(CAD)된 입력정보가 자동생산 System(CAM system)에 의해 정확히 원하는 제품으로 출력되 나오는데엔 여러가지 복합적인 기술 즉, 정보처리기술이라 할 수 있는 system engineering및 컴퓨터기술과 생산기술이라 할 수 있는 기계, 전기, 전자기수로가 계측기술등의 조화가 필요하다.