For highly contaminated elements such as reactor pressure vessels or reactor internals, it is a viable option to cool-down and dismantle these elements in submerged (e.g. underwater) state. Several tools and processes such as saw cutting, water jet cutting or plasma cutting are currently used for underwater cutting, with each of them having their own advantages and disadvantages. The main disadvantage of these existing methods, especially saw and water jet cutting, is the generation of secondary waste that then needs to be filtered out of the water. In addition, in the case of water jet cutting, a considerable amount of abrasive material is added, which must also be stored. To overcome this drawback, the feasibility of using laser cutting under water to minimize secondary waste production has been actively studied recently. One of the challenges with the underwater laser cutting is to visually monitor the cutting process. Flowing air bubbles generated by the cutting gas and the flashing light emitted from the laser and melting material prohibit visual monitoring of the cutting process. This study introduces a method to enhance the video from a monitoring camera. Air bubbles can be detected by computing optical flows and the video quality can be enhanced by selective removal of the detected bubbles. In addition, suppressing the frame image update from flashing light area can also effectively enhance the video quality. This paper describes the simple yet effective video quality enhancement method and reports preliminary results.

The cable-based retractable membrane roof makes it impossible to maintain its shape and stiffness during driving process, unlike the hard-type retractable roof. Consequently, monitoring using a relatively simple wireless video transmission device is required. However, since video data has a bigger transmission rating than other monitoring data in terms of the structure velocity or acceleration, there is a need to develop transmission device that is easy to install and entails low maintenance cost. This paper studies on a real-time video transmission system for monitoring the cable-based retractable membrane roof while driving. A video transfer software, using the mobile network, is designed and the embedded system is constructed. Ultimately, the data transmission server is tested. Connecting a trolley to the system allows testing of the validity and efficiency of the developed system through the video data transmitted in the driving process. Result of the test shows that the developed system enables multi-device data transfer with monitoring via the mobile network.

본 연구에서는 소셜 비디오 플랫폼 환경에서 동영상 기반 커뮤니케이션을 통해 동영상을 시청하는 사용자와 타인 들 간의 관계가 사용자의 긍정적 감정과 사회적 소속감에 어떠한 영향을 미치는지 살펴보았다. 해당 연구에서는 사 회 충격 이론(Social Impact Theory)과 자기 점검 이론(Self-Monitoring Theory)이라는 심리학 이론을 토대로 동영상 기반의 새로운 상호작용 수단을 활용한 대안을 검증하기 위해 실제 동영상 기반의 소셜 비디오 플랫폼 환경을 구축 하여 실험 연구를 진행하였다. ANOVA 분석 결과, 동영상을 보는 환경에서 타인의 모습이 실시간으로 보일 때, 또는 나 자신의 얼굴이 화면에 함께 제시될 때, 그렇지 않을 때 보다 사용자는 긍정적인 감정과 사회적 소속감을 더 크게 느끼는 것을 확인할 수 있었다. 또한 위의 두 조건이 동시에 제공될 때가 그렇지 않을 때보다 사용자들이 느끼는 긍정적 감정의 증가 폭이 더 컸다. 본 연구 결과를 통해 궁극적으로 새로운 소셜 비디오 플랫폼의 형태에 대한 통찰을 얻을 수 있을 것이라 기대한다.

A video-based non-contact remote displacement measurement system is proposed and developed. The system captures images of the structure and analyzes the image to determine the displacement. Multi-thread computing and adaptive region of interest method is implemented in the system to compute the displacement in real-time. Field test on a real structure has been carried out to evaluate the performance and verify the reliability of the system.