A performance evaluation method to compare the multi-view point cloud data registration based on ICP algorithm and reference marker

Registration of range images of surfaces is a fundamental problem in three-dimensional modelling. This process is performed by finding a rotation matrix and translation vector between two sets of data points requiring registration. Many techniques have been developed to solve the registration problem. Therefore, it is important to understand the accuracy of various registration techniques when we decide which technique will be selected to perform registration task. This paper presents a new approach to test and compare registration techniques in terms of accuracy. Among various registration methods, iterative closest point-based algorithms and reference marker methods are two types of commonly applied methods which are used to accomplish this task because they are easy to implement and relatively low cost. These two methods have been selected to perform a comprehensively quantitative evaluation by using the proposed method and the registration results are verified using the calibrated NPL freeform standard

Geometric Modeling

A comprehensive, up-to-date presentation of all the indispensable core concepts of geometric modelling. Now completely updated to reflect the most recent developments in the field, Geometric Modelling clearly presents and compares all the important mathematical approaches to modelling curves, surfaces, and solids, and shows how to shape and assemble these elements into more complex models. Its thorough coverage also includes the concomitant geometric processing necessary, e.g., the computation of intersections, offsets, and fillets. Written in a style that is virtually free of the jargon of special applications, this unique book focuses on the essence of geometric modelling and treats it as a discipline in its own right. This integrated approach allows the reader to focus on the principles and logic of geometric modelling without requiring background knowledge of CAD/CAM, computer graphics, or computer programming. Supported by more than 300 illustrations, Geometric Modelling appeals to the reader's visual and intuitive skills in a way that makes understanding the more abstract concepts much easier. This new edition features a host of new application areas, including topology, special effects in cinematography, the design and control of type fonts, and virtual reality, as well as numerous application examples. For computer graphics specialists, application designers and developers, scientific programmers, and advanced students, Geometric Modelling, Second Edition will serve as a complete and invaluable guide to the entire field.

Adjoint Optimization of a Wing Using the CSRT Method

This paper will demonstrate the potential of the Class-Shape-Refinement-Transformation (CSRT) method for aerodynamically optimizing three-dimensional surfaces. The CSRT method was coupled to an in-house Euler solver and this combination was used in an optimization framework to optimize the ONERA M6 wing in transonic conditions. The gradients of the flow variables with respect to the design parameters were computed using an adjoint solver integrated in the Euler code. The optimization was performed by a trust region reflective algorithm. A two-step approach was used to optimize the wing. First, a “general” optimization was done using the Bernstein coefficients of the shape function. Second, a “regional” refinement was performed using the B-spline coefficients of the refinement function. It was shown that using this strategy a considerable improvement of the lift-to-drag ratio of 22 % could be achieved. This result proves that an adjoint optimization using the CSRT method is an effective way to improve transonic wing performance.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin

Achieving Privacy Preservation when Sharing Data for Clustering

In this paper, we address the problem of protecting the underlying attribute values when sharing data for clustering. The challenge is how to meet privacy requirements and guarantee valid clustering results as well

Development of a Computer Application to Simulate Porous Structures

Geometric modeling is an important tool to evaluate structural parameters as well as to follow the application of stereological relationships. The obtention, visualization and analysis of volumetric images of the structure of materials, using computational geometric modeling, facilitates the determination of structural parameters of difficult experimental access, such as topological and morphological parameters. In this work, we developed a geometrical model implemented by computer software that simulates random pore structures. The number of nodes, number of branches (connections between nodes) and the number of isolated parts, are obtained. Also, the connectivity (C) is obtained from this application. Using a list of elements, nodes and branches, generated by the software, in AutoCAD® command line format, the obtained structure can be viewed and analyzed