The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Deddy Chrismianto - One of the best experts on this subject based on the ideXlab platform.

  • development of cubic bezier curve and curve Plane Intersection method for parametric submarine hull form design to optimize hull resistance using cfd
    Journal of Marine Science and Application, 2015
    Co-Authors: Deddy Chrismianto, Ahmad Fauzan Zakki, Berlian Arswendo, Dong Joon Kim
    Abstract:

    Optimization analysis and computational fluid dynamics (CFDs) have been applied simultaneously, in which a parametric model plays an important role in finding the optimal solution. However, it is difficult to create a parametric model for a complex shape with irregular curves, such as a submarine hull form. In this study, the cubic Bezier curve and curve-Plane Intersection method are used to generate a solid model of a parametric submarine hull form taking three input parameters into account: nose radius, tail radius, and length-height hull ratio (L/H). Application program interface (API) scripting is also used to write code in the ANSYS design modeler. The results show that the submarine shape can be generated with some variation of the input parameters. An example is given that shows how the proposed method can be applied successfully to a hull resistance optimization case. The parametric design of the middle submarine type was chosen to be modified. First, the original submarine model was analyzed, in advance, using CFD. Then, using the response surface graph, some candidate optimal designs with a minimum hull resistance coefficient were obtained. Further, the optimization method in goal-driven optimization (GDO) was implemented to find the submarine hull form with the minimum hull resistance coefficient (C t ). The minimum C t was obtained. The calculated difference in C t values between the initial submarine and the optimum submarine is around 0.26%, with the C t of the initial submarine and the optimum submarine being 0.001 508 26 and 0.001 504 29, respectively. The results show that the optimum submarine hull form shows a higher nose radius (r n ) and higher L/H than those of the initial submarine shape, while the radius of the tail (r t ) is smaller than that of the initial shape.

  • parametric bulbous bow design using the cubic bezier curve and curve Plane Intersection method for the minimization of ship resistance in cfd
    Journal of Marine Science and Technology, 2014
    Co-Authors: Deddy Chrismianto
    Abstract:

    Parametric geometric modeling plays an important role in ship’s hull form optimization by use of computational fluid dynamic (CFD) analysis. However, it is difficult to create satisfactory parametric modeling for some curved shapes, such as a ship’s bulbous bow. In this study, the cubic Bezier curve and curve-Plane Intersection methods are applied to generate the parametric design of a bulbous bow in a solid modeling procedure by taking into account the input of 4 (four) design parameters. For this, a suitable application program interface script within the ANSYS Design Modeler was developed. An application to the ship resistance minimization by use of CFD was made to show that the proposed method could be implemented properly. In this respect, the parametric design of the bulbous bow of a container ship (KRISO Container Ship type) was chosen to be modified. First, it was shown that the computational results generated by CFD were close to the experimental data for the original ship hull form. The developed optimization method was subsequently applied to find the optimal bulbous bow. Finally, the dependence of the optimum bulbous bow on a ship’s speed (some variations of Fn values) was investigated and the results were compared to each other.

Vaclav Skala - One of the best experts on this subject based on the ideXlab platform.

  • algorithms for line and Plane Intersection with a convex polyhedron with o sqrt n expected complexity in e3
    International Conference on Computer Graphics and Interactive Techniques, 2014
    Co-Authors: Vaclav Skala
    Abstract:

    Efficiency of Intersection algorithms is fundamental for solving many problems in computer graphics, e.g. line and polygon clipping etc. For a line clipping by a convex polyhedron the well known Cyrus-Beck's (CB) algorithm is usually used with O(N) complexity, where N is a number of facets. For a Plane clipping by a convex polyhedron algorithms used are of O(N) complexity. On the contrary, in the E2 case, the order is given by indexes of the polygon vertices, which leads to O(lg N) computational complexity [Skala 1994]. However, an Intersection of a Plane and a convex polyhedron given as a triangular mesh, results to a convex polyline lying on a Plane in a general position in E3.

Dong Joon Kim - One of the best experts on this subject based on the ideXlab platform.

  • development of cubic bezier curve and curve Plane Intersection method for parametric submarine hull form design to optimize hull resistance using cfd
    Journal of Marine Science and Application, 2015
    Co-Authors: Deddy Chrismianto, Ahmad Fauzan Zakki, Berlian Arswendo, Dong Joon Kim
    Abstract:

    Optimization analysis and computational fluid dynamics (CFDs) have been applied simultaneously, in which a parametric model plays an important role in finding the optimal solution. However, it is difficult to create a parametric model for a complex shape with irregular curves, such as a submarine hull form. In this study, the cubic Bezier curve and curve-Plane Intersection method are used to generate a solid model of a parametric submarine hull form taking three input parameters into account: nose radius, tail radius, and length-height hull ratio (L/H). Application program interface (API) scripting is also used to write code in the ANSYS design modeler. The results show that the submarine shape can be generated with some variation of the input parameters. An example is given that shows how the proposed method can be applied successfully to a hull resistance optimization case. The parametric design of the middle submarine type was chosen to be modified. First, the original submarine model was analyzed, in advance, using CFD. Then, using the response surface graph, some candidate optimal designs with a minimum hull resistance coefficient were obtained. Further, the optimization method in goal-driven optimization (GDO) was implemented to find the submarine hull form with the minimum hull resistance coefficient (C t ). The minimum C t was obtained. The calculated difference in C t values between the initial submarine and the optimum submarine is around 0.26%, with the C t of the initial submarine and the optimum submarine being 0.001 508 26 and 0.001 504 29, respectively. The results show that the optimum submarine hull form shows a higher nose radius (r n ) and higher L/H than those of the initial submarine shape, while the radius of the tail (r t ) is smaller than that of the initial shape.

Robert Zlot - One of the best experts on this subject based on the ideXlab platform.

  • line based extrinsic calibration of range and image sensors
    International Conference on Robotics and Automation, 2013
    Co-Authors: Peyman Moghadam, Michael Bosse, Robert Zlot
    Abstract:

    Creating rich representations of environments requires integration of multiple sensing modalities with complementary characteristics such as range and imaging sensors. To precisely combine multisensory information, the rigid transformation between different sensor coordinate systems (i.e., extrinsic parameters) must be estimated. The majority of existing extrinsic calibration techniques require one or multiple planar calibration patterns (such as checkerboards) to be observed simultaneously from the range and imaging sensors. The main limitation of these approaches is that they require modifying the scene with artificial targets. In this paper, we present a novel algorithm for extrinsically calibrating a range sensor with respect to an image sensor with no requirement of external artificial targets. The proposed method exploits natural linear features in the scene to precisely determine the rigid transformation between the coordinate frames. First, a set of 3D lines (Plane Intersection and boundary line segments) are extracted from the point cloud, and a set of 2D line segments are extracted from the image. Correspondences between the 3D and 2D line segments are used as inputs to an optimization problem which requires jointly estimating the relative translation and rotation between the coordinate frames. The proposed method is not limited to any particular types or configurations of sensors. To demonstrate robustness, efficiency and generality of the presented algorithm, we include results using various sensor configurations.

Sarat Singamneni - One of the best experts on this subject based on the ideXlab platform.

  • curved layer adaptive slicing clas for fused deposition modelling
    Rapid Prototyping Journal, 2015
    Co-Authors: Bin Huang, Sarat Singamneni
    Abstract:

    Purpose – This paper aims to develop a new slicing method for fused deposition modelling (FDM), the curved layer adaptive slicing (CLAS), combining adaptive flat layer and curved layer slicing together. Design/methodology/approach – This research begins with a review of current curved layer and adaptive slicing algorithms employed in the FDM and further improvement of the same, where possible. The two approaches are then integrated to develop the adaptive curved layer slicing based on the three-Plane Intersection method for curved layer offsetting and consideration of facet angles together with the residual heights for adaptive slicing. A practical implementation showed that curved layer adaptive layers respond in similar lines to the flat layer counterparts in terms of the mechanical behaviour of FDM parts. Findings – CLAS is effective in capturing sharply varying surface profiles and other finer part details, apart from imparting fibre continuity. Three-point bending tests on light curved parts made of ...