• Structural Engineering and Mechanics
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• v.76 no.5
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• pp.591-598
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• 2020

Ultrasonic waves provide a non-destructive and sensitive way to monitor the concrete hydration. However, limited works are reported to monitor the evolution of the mechanical parameter at early ages. In this study, modified piezoelectric aggregates are embedded inside a concrete beam to excite and receive primary waves. A hydration index, namely, the variation of ultrasonic waveform (VUW) is developed to characterize the variation of the transmitted waves during the hydration process. The recorded hydration indices are compared with the compressive strength measured by destructive test at different ages. The results show that the VUW is closer to the compressive strength than the other two traditional hydration indices, ultrasonic velocity and wave packet energy. The proposed VUW provides a simple and accurate way to monitor the concrete hydration at early ages.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.55-56
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• 2020

The construction industry has the highest occupational fatality and injury rates related to accidents of any industry. Accordingly, safety managers closely monitor to prevent accidents in real-time by installing surveillance cameras at construction sites. However, due to human cognitive ability limitations, it is impossible to monitor many videos simultaneously, and the fatigue of the person monitoring surveillance cameras is also very high. Thus, to help safety managers monitor work and reduce the occupational accident rate, a study on object recognition in construction sites was conducted through surveillance cameras. In this study, we applied to the instance segmentation to identify the classification and location of objects and extract the size and shape of objects in construction sites. This research considers ways in which deep learning-based computer vision technology can be applied to safety management on a construction site.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.907-913
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• 2023

Currently, the sprinkler method is widely used as an initial suppression method in existing firefighting systems. However, this method can cause significant damage to both equipment and facilities in the hydration area. To minimize this damage, fire extinguishing monitors are being developed that can spray fire extinguishing water directly at the point of fire. These monitors are installed on the top floor of the ship, such as the Living Quarter and Ventilation System. While conventional fire extinguishing monitors focus on lightweight research with a short spray port and require a spray distance of about 40 to 45m, recent developments necessitate a longer spray port, similar to a water cannon, requiring a spray distance of about 70 to 75m. This study aims to predict the injection distance of both the existing ship-installed fire extinguisher and the long spray port fire extinguisher through hydrodynamic computer analysis, and to determine whether the injection distance has increased.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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• pp.69-74
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• 1998

In order to monitor the tool wear in milling operation, cutting force is measured as the tool wear increased. The digital signal processing methods are used to detect the tool wear . As AR parameter extract the feature of tool wear , it can be used as input parameter of pattern classifier. The FFT monitor the tool wear exactly , but it can not do real time signal processing. The band energy method can be used to real time monitoring of tool wear ,but int can degrade the exact monitoring.

• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.209-211
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• 1986

This paper describes the design of portable arrhythmia monitor and associated algorithm for automated diagnosis based-on micro-computer in the ambulatory ECG recording, analysis, and transmitting to a hospital host computer immediately through the telephone system.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.387-390
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• 1997

Grinding process takes a long time that grinding machine is setted properly. It is difficult for user to judge correctly the abnormal states generated in grinding process. Air grinding has to be reduced for the improvement of productivity. In addition, it is important to monitor the dressing and the grinding process so that the grinding working maintains optimal grinding conditions. In this study, the monitoring system using the acoustic emission is developed to monitor these processes continuously. This system was able to reduce the preparation as well as the machine setting time in grinding operation.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.270-273
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• 2001

The fluorescence sensor is utilized to monitor the complex fluorescence patterns of intra- and extracellular components in cultivation processes. Especially biogenic fluorophores such as proteins and peptides (tryptophan, phenylalanine), coenzymes (FAD, NAD(P)H) and vitamins (riboflavin, pyridoxine) within cells are detected by a fluorescence sensor. In this work a 2-dimensional fluorescence sensor has been used to monitor a production process of itaconic acid by Aspergillus terreus and the on-line monitored spectra data can be con-elated to off-line data measured by a few methods.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.819-822
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• 2001

In this study a fiber optic biosensor has been developed to on-line monitor the concentrations of oxygen and glucose. The oxygen concentrations in solution and gas phase monitored by the fiber optic sensor has been compared with those by a dissolved oxygen electrode and an IR-type $O_2$ analyzer. The fiber optic glucose sensor has been made by immobilizing glucose oxidase on the tip of the optic fiber and used to on-line monitor the concentration of glucose in a fermentation process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.149-154
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• 2002

In a high speed spindle system, it is very important to monitor the state of rotating rotor. Particularly in active control spindle system, the position sensor must provide feedback to the control system on the exact position of the rotor. In order to monitor the state of a high speed spindle exactly, high accuracy and wide frequency bandwidth of sensors are important. This paper observes the factors which has an effect on dynamic performances of inductive position sensor.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.713-718
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• 1996

Risk Monster는 한국원자력연구소에서 개발한 risk monitor로서 발전운영시 및 정비계획시 원전의 기기 운영 상태 (=Configuration)의 실제 변경이나 계획시 이에 따른 원전의 안전성 (또는 Risk)를 평가 및 감시하는 시스템이다. 안전성은 노심손상 빈도를 가지고 평가하며 이 Risk Monster의 국내 원전에의 활용, 특히 on-line maintenance시의 활용을 모색하였다. 외국에서처럼 국내 원전에서도 risk monitor를 이용한 on-line maintenance를 실시 하여 원전의 경제성 및 안전성을 향상 시켜야 한다.