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101.
102.
J. Jesús Cervantes-Sánchez José M. Rico-Martínez Alejandro Tadeo-ChávezGerardo I. Pérez-Soto 《Robotics and Computer》2011
It is presented an integral approach for the kinematic design of spatial, hybrid closed chains which include planar parallelograms into their kinematic structure. It is based on a systematic application of recursive formulae intended for describing the evolution of screws through time. Due to the particular nature of the proposed approach, it can be closely related with Lie algebras and allows to overcome the lacking of group structure offered by a parallelogram when it is going to be considered as a component of a hybrid closed chain. Several application examples are presented in order to show the potential of the proposed approach. 相似文献
103.
R. InglésAuthor Vitae J. PallaresAuthor VitaeI. GràciaAuthor Vitae A.M. GuéAuthor VitaeJ.L. RamirezAuthor Vitae 《Sensors and actuators. A, Physical》2011,172(1):124-128
We use electro-thermal simulations to design thermally insulated membranes that support thin film heaters as components of gas preconcentrators. These heaters provide a good thermal homogeneity ensuring a narrow desorption peak and, thus, a good sensor response. Temperature measurements have been carried out using an infrared camera and they are in agreement with the corresponding numerical predictions. Our model has been validated and it can be used in future designs. 相似文献
104.
基于上下位机结构设计光学非球面检验系统,采用工控机作为上位机,下位机由运动控制卡和数据采集卡构成.通过计数器协调运动控制单元和数据采集单元的动作,可实现检测过程坐标的准确定位和高精度的数据采集.对一般非球面方程进行变换后,采用最小二乘拟合算法对数据进行曲面拟合处理.并可适当增加测量点数据来减少测量误差.通过数据实验表明... 相似文献
105.
106.
We present a novel mesh denoising and smoothing method in this paper. Our approach starts by estimating the principal curvatures
and mesh saliency value for each vertex. Then, we calculate the uniform principal curvature of each vertex based on the weighted
average of local principal curvatures. After that, we use the weighted bi-quadratic Bézier surface to fit the neighborhood
of each vertex using the least-square method and obtain the new vertex position by adjusting the parameters of the fitting
surface. Experiments show that our smoothing method preserves the geometric feature of the original mesh model efficiently.
Our approach also prevents the volume shrinkage of the input mesh and obtains smooth boundaries for non-closed mesh models. 相似文献
107.
Medial axis computation for planar free-form shapes 总被引:1,自引:0,他引:1
We present a simple, efficient, and stable method for computing—with any desired precision—the medial axis of simply connected planar domains. The domain boundaries are assumed to be given as polynomial spline curves. Our approach combines known results from the field of geometric approximation theory with a new algorithm from the field of computational geometry. Challenging steps are (1) the approximation of the boundary spline such that the medial axis is geometrically stable, and (2) the efficient decomposition of the domain into base cases where the medial axis can be computed directly and exactly. We solve these problems via spiral biarc approximation and a randomized divide & conquer algorithm. 相似文献
108.
Nils Hasler Carsten Stoll Bodo Rosenhahn Thorsten Thormhlen Hans-Peter Seidel 《Computers & Graphics》2009,33(3):211
The paper presents a method to estimate the detailed 3D body shape of a person even if heavy or loose clothing is worn. The approach is based on a space of human shapes, learned from a large database of registered body scans. Together with this database we use as input a 3D scan or model of the person wearing clothes and apply a fitting method, based on ICP (iterated closest point) registration and Laplacian mesh deformation. The statistical model of human body shapes enforces that the model stays within the space of human shapes. The method therefore allows us to compute the most likely shape and pose of the subject, even if it is heavily occluded or body parts are not visible. Several experiments demonstrate the applicability and accuracy of our approach to recover occluded or missing body parts from 3D laser scans. 相似文献
109.
基于小波多分辨率分析的指横纹定位新算法 总被引:2,自引:0,他引:2
针对指横纹感兴趣区域(ROI)难以准确定位的问题,在明确提出指横纹ROI定义的前提下,提出利用小波多分辨率分析进行指横纹ROI自动检测定位的新算法.该方法利用纹理相似性原理,在高频子图采用基于特征向量和区域生长法产生指横纹的候选子区域集合,然后利用低频子图Radon投影得到的指横纹的区域特征对候选子区域进行验证,最后结合直线拟合手指轮廓得到指横纹在原图的有效位置,最终实现指横纹ROI的精准定位.实验证明该算法不仅能有效克服噪声以及手形姿态变化的影响,并且对多种情况有很强的鲁棒性. 相似文献
110.