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目前,安全阀在线校验系统普遍存在精度低、安全性和便携性差等缺点.提出了以STC12C5A单片机为核心,基于阀瓣微动技术的便携式安全阀自动校验仪的设计方案,并完成了对该压力校准系统的研制.工程应用表明,该仪器具有精度高、功耗低等特点,能实现数据共享,操作灵活,易于携带,在行业中具有很高的推广价值. 相似文献
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分析了MERSI与MODIS间光谱响应差异对测量表观反射比的影响。正演模拟结果显示,在极区冰雪情况下,MERSI与MODIS测量得到的表观反射比之间的相对差异是关于MODIS所测表观发射比的二次函数。MERSI的前4个通道与对应的MODIS通道之间的相对差异在0~0.8%,0~2%,0.5%~2.5%,-1.8%~-0.8%之间。将正演模拟得到的对光谱响应差异的修正关系应用到具体的SNO测量后,MERSI前3个通道的表观反射比与修正后MODIS的表观反射比之间的相对差异减小到了3%以内。MERSI的1、2通道在红外波段也有响应,这部分响应在极区冰雪条件下对表观反射率的影响在0.5%左右,基本可以忽略。 相似文献
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Junfa LiuAuthor Vitae Yiqiang ChenAuthor VitaeMingjie LiuAuthor Vitae Zhongtang ZhaoAuthor Vitae 《Neurocomputing》2011,74(16):2566-2572
Indoor location estimation based on Wi-Fi has attracted more and more attention from both research and industry fields. It brings two significant challenges. One is requiring a vast amount of labeled calibration data. The other is real-time training and testing for location estimation task. Traditional machine learning methods cannot get high performance in both aspects. This paper proposed a novel semi-supervised learning method SELM (semi-supervised extreme learning machine) and applied it to sparse calibrated location estimation. There are two advantages of the proposed SELM. First, it employs graph Laplacian regularization to import large number of unlabeled samples which can dramatically reduce labeled calibration samples. Second, it inherits the good property of ELM on extreme training and testing speed. Comparative experiments show that with same number of labeled samples, our method outperforms original ELM and back propagation (BP) network, especially in the case that the calibration data is very sparse. 相似文献
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In this paper, a new multi-sensor calibration approach, called iterative registration and fusion (IRF), is presented. The key idea of this approach is to use surfaces reconstructed from multiple point clouds to enhance the registration accuracy and robustness. It calibrates the relative position and orientation of the spatial coordinate systems among multiple sensors by iteratively registering the discrete 3D sensor data against an evolving reconstructed B-spline surface, which results from the Kalman filter-based multi-sensor data fusion. Upon each registration, the sensor data gets closer to the surface. Upon fusing the newly registered sensor data with the surface, the updated surface represents the sensor data more accurately. We prove that such an iterative registration and fusion process is guaranteed to converge. We further demonstrate in experiments that the IRF can result in more accurate and more stable calibration than many classical point cloud registration methods. 相似文献
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Recently, various techniques of shape reconstruction using cast shadows have been proposed. These techniques have the advantage
that they can be applied to various scenes, including outdoor scenes, without using special devices. Previously proposed techniques
usually require calibration of camera parameters and light source positions, and such calibration processes limit the range
of application of these techniques. In this paper, we propose a method to reconstruct 3D scenes even when the camera parameters
or light source positions are unknown. The technique first recovers the shape with 4-DOF indeterminacy using coplanarities
obtained by cast shadows of straight edges or visible planes in a scene, and then upgrades the shape using metric constraints
obtained from the geometrical constraints in the scene. In order to circumvent the need for calibrations and special devices,
we propose both linear and nonlinear methods in this paper. Experiments using simulated and real images verified the effectiveness
of this technique. 相似文献
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