This paper introduces a study on measuring the 3D vibration displacement of plate structure using Digital Image Correlation (DIC) applied to stereo digital continuous camera images. The proposed method is a non-contact 3D displacement measurement method that does not require physical sensors to be attached to the structure, and it has the advantage of simultaneously measuring dynamic displacements at multiple points on the structure. Theoretically, multiple cameras can be used, but in this study, two cameras were used to capture continuous images of the vibrating structure, and the image coordinates of multiple tracking points at arbitrary positions on the structure were measured using correlation matching. Using these image coordinates as input data, the dynamic 3D positions were calculated through Space intersection, successfully determining the 3D dynamic displacements. The measured dynamic displacements were validated for accuracy by comparing them with values measured by laser displacement sensors. And frequencies of measured data were validated by comparing with computational modal analysis by Finite Element Model (FEM).
컴퓨터방사선촬영 시스템이 도입되면서 영상판은 분명 우리에게 많은 정보, 정밀한 디지털이미지 제공, 재촬영률 감소 등 상당한 이점으로 다가왔다. 컴퓨터방사선촬영 시스템의 영상판을 이용한 의료 영상 획득시 좋은 영상을 얻기 위해서는 영상판의 보관 장소 및 발광시간의 응답 특성과 잠상퇴행 현상을 인지함과 동시에 효과적인 정도관리와 화질 향상을 위해 체계적인 관리와 노력을 해야 할 것으로 판단한다. 본 연구에서는 컴퓨터방사선촬영 시스템의 영상판을 이용한 영상획득 과정에서 발생할 수 있는 자연 환경에 의한 잡음에 대하여 알아보았다. 실험 결과 시간이 지남에 따라 영상판에 잡음이 생성되며 영상의 신뢰성이 떨어지게 됨을 확인하였다. 영상판을 사용할 경우에는 4시간 이상 보관된 영상판에 대해서는 잠상소거를 반드시 실시해서 사용하고, 2회 이상 잠상소거 하는 것이 가장 좋은 방법일 것이라고 판단한다. 본 연구는 임상에서 영상판 관리 및 사용 시 정량적인 참고자료가 될 것이다.
With the introduction of the one-tolling and smart-tolling, Vehicle number recognition technology of ITS imaging equipment that was used to prevent the escape and tolling evasion will play an important role in the collection system. Korea Highway Corporation will prepare a ITSK-00088 Performance Assessment to improve the license plate recognition. and there are a number of efforts to improve the accuracy of vehicle number recognition. But even if the ITS equipment had passed the performance assessment, it is in a situation which does not achieve the target value due to physical and environmental factors. we propose a method for acquiring the additional information(color, type, pattern) including plate number of the vehicle in order to improve the recognition rate of the vehicle number. Through that link the vehicle additional information, vehicle specifications DB, image analysis system, the goal is to build a system that can be identified for the misrecognized and unrecognized vehicle.
With the introduction of the one-tolling and smart-tolling, Vehicle number recognition technology of ITS imaging equipment that was used to prevent the escape and tolling evasion will play an important role in the collection system. Korea Highway Corporation will prepare a ITSK-00088 Performance Assessment to improve the license plate recognition. and there are a number of efforts to improve the accuracy of vehicle number recognition. But even if the ITS equipment had passed the performance assessment, it is in a situation which does not achieve the target value due to physical and environmental factors. we propose a method for acquiring the additional information(color, type, pattern) including plate number of the vehicle in order to improve the recognition rate of the vehicle number. Through that link the vehicle additional information, vehicle specifications DB, image analysis system, the goal is to build a system that can be identified for the misrecognized and unrecognized vehicle.