Development of new concept bending sensor and signal processing algorithm based on optical fiber Bragg grating for 3D shape monitoring of flexible cable This study presents the design and fabrication of a novel fiber-optic bending sensor and its driving optical system, utilizing three Bragg grating sensors inscribed in bare optical fibers with a diameter of 250 μm. A multi-point bending measurement system and dedicated signal processing algorithm are developed to enable accurate monitoring of three-dimensional shapes. Furthermore, the proposed approach is extended to the development of a flexible cable integrated with the fiber-optic bending sensor, capable of self-shape measurement. The resulting technology provides a promising platform for advanced nondestructive testing applications.

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Development of Optical Fiber Sensor for Visualization Analysis of Next Generation Power Semiconductor Thermal Characteristics for AI Applications This research focuses on the development of fiber-optic sensors for the visualization and analysis of thermal characteristics in next-generation power semiconductors with artificial intelligence applications. By optimizing the performance design of fiber Bragg grating (FBG) sensor heads, it becomes possible to establish measurement technologies for temperature, thermal stress, and mechanical stress within power conversion devices. Through this study, an advanced measurement system capable of monitoring temperature, strain, and thermal stress both inside and outside power semiconductor packaging will be developed, which can be further extended and applied to a wide range of semiconductor systems.

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Development of Plastic Optical Fiber based Heart Beat Sensor Module With the rapid growth of the elderly population in South Korea, concerns about sudden deaths, primarily caused by cardiovascular diseases such as acute cardiac arrest, have been increasing. To address this challenge, our research explores the development of a portable and cost-effective heartbeat sensor designed for home use. The sensor is based on the Plastic Optical Fiber–Photoplethysmogram (POF-PPG) principle, which measures blood flow and heart rate by analyzing light interactions with blood vessels. Unlike conventional PPG sensors that directly connect the transmitter and receiver, our design incorporates POF between the two components, thereby reducing optical and thermal interference at the receiver. Furthermore, by applying advanced filtering techniques, the system achieves improved measurement accuracy, making it a promising tool for accessible cardiovascular monitoring in daily life.

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Development of Fiber Optic Sensor System for Multiplexing of Ultrasonic Waves in Real-time Structural Health Monitoring The mechanical structures included in civil/architecture structures need the non-destructive detection system for structural health monitoring in real-time for safety nowaday. Compared to the non-destructive detection system using an existing sensor system, fiber optic sensor has many advantages. Therefore, a study of fiber optic sensor system has been conducted to measure various physical values. Under the various study of fiber optic sensor system, our laboratory has studied the fiber optic sensor system to measure the acoustic wave and ultrasonic wave induced from structural damage.

Development of GUI-Software for Real-time Signal Processing based on Internet The nuclear power plant that requires the safety has a potential risk. Therefore, it needs the integrated structural health monitoring system to detect the damage of structure easily. The aim of this project is to develop a work software based on moire-fringe fiber optic sensor system for the nuclear power plant monitoring. For this purpose, we have studied the phase-compensation algorithm to make the 90 degree between two signals and the development of software based on graphic user interface(GUI).

Development of SHM Technologies for High Speed Mobile Robot with Ultrasonic NDE for the Surface of Pipework in PHWR The nuclear power plant must perform the safety inspection of pipes because it can occur the casualties by leak of pipe. But, the many pipes of nuclear power plant have difficult access and limitation of inspection. Therefore, it is needed the mobile robot to inspect the pipe of the nuclear power plant. If this robot is used for the inspection of the pipe in nuclear power plant, it will overcome the limitation of inspector and improve the reliability of the pipe. For this purpose, this project has studied the non-destructive inspection system development using EMAT(Electromagnetic Acoustic Transducer) mounted on the robot system.