RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • New Calibration Method of Two-Dimensional Laser Scanner and Camera Based on LM-BP Neural Network

        Jianlei Kong,Li Fan,Jinhao Liu,Lei Yan,Xiaokang Ding 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.7

        The calibration between a camera and a two-dimensional laser scanner (2DLS) is an essential step in the object detecting system. Many algorithms with linear model have been proposed. But these tend to solve intrinsic and extrinsic calibration parameters separately and are influenced seriously by the poor initial data, which leads to unstable and inaccurate results. Hence, a new nonlinear model based on the Back Propagation neural network trained by the Levenberg-Marquardt algorithm (LM-BP) is presented for calibration in this paper. Before the calibration, the original laser data is fitted linearly to avoid the ranging error and is optimized by an angular increment to reduce the step-angular error. Then, the calibration network with 4 inputs composed of the lasers points’ coordinates and constant 1, and 2 outputs are obtained, expected values of which are the coordinates of corresponding points in the image coordinates. The sum of square of errors between the network outputs and expected values is taken to adjust the modifications of the weights and thresholds with the Levenberg-Marquardt method to optimize the calibration model. Finally, compared with related researches, experimental results show that the accuracy of calibration between camera and 2DLS is significantly improved, and the detecting system is more suitable for actual measurement situations.

      • KCI등재

        Characteristic of SiC Slurry in Ultra Precision Lapping of Sapphire Substrates

        Tao Yin,ZhiDa Wang,Toshiro Doi,Syuhei Kurokawa,Zhe Tan,XiaoKang Ding,Huan Lin 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.6

        A method is proposed in this paper to prepare a SiC slurry with SiC particles selected by an ultrasonic-assisted elutriation method to reduce substrate surface damage caused by abrasive particles during lapping. Sapphire substrate lapping experiments were carried out using the prepared SiC slurry, and the lapping performance of the slurry was analyzed. The experimental results show that the SiC particle size is a factor that directly affects the material removal rate and surface roughness Ra, of sapphire substrates. When a SiC slurry with a particle size of 630 nm was used, the material removal rate was 508 nm/h, and the surface roughness Ra was 1.9 nm; increasing the slurry concentration and the platen rotating speed can improve the material removal rate. In addition, the agglomeration of SiC particles in the slurry depends on the pH of the slurry. Efficient precision lapping of sapphire substrates can be achieved by selecting appropriately sized SiC particles and by adjusting the slurry pH to control the agglomeration and dispersion of SiC particlesto further reduce the scratches on the substrate surface during the lapping process.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼