A Point-Structured Geometric Modeling Approach to Foot Shape Representation

2012 ◽  
Author(s):  
Ming J. Tsai ◽  
Hung W. Lee ◽  
Hsueh Y. Lung
Keyword(s):  
Geometric Modeling ◽  
Shape Representation ◽  
Geometric Model ◽  
Quantitative Description ◽  
Compact Representation ◽  
Shape Information ◽  
Modeling Approach ◽  
Data Points ◽  
3D Geometric Model ◽  
Structured Representation

A compact representation for the quantitative description of foot shape is important not only for the foot measurement and anthropometry, but also for the ergonomic design of footwear. Based on foot scanned data, a novel point-structured geometric modeling approach to the reduction of 3D point cloud and the preservation of shape information is proposed. The semantic descriptions of foot features are interpreted into logical definitions. A total of fifteen feature points are thus defined. Finally, there are only a total of 2,093 data points needed in such a point-structured representation. Based on it, it is easy to fetch not only the 1D and 2D measurements, but also the 3D feature curves of the foot shape. It can provide a compact 3D geometric model to serve as a significant database for the individuals and, thereby, becomes a useful tool in investigating the foot and manufacturing the foot related apparel and devices.

scholarly journals Class Representation of Shapes Using Qualitative-codes

10.14311/224 ◽  
2001 ◽  
Vol 41 (3) ◽  
Author(s):  
Ashraf Fouad Hafez Ismail
Keyword(s):  
Coding Theory ◽  
Geometric Modeling ◽  
Shape Representation ◽  
Simple Task ◽  
Shape Information ◽  
Shape Comparison ◽  
Qualitative Shape ◽  
Shape Descriptions ◽  
Cartesian Coordinate ◽  
Class Representation

This paper introduces our qualitative shape representation formalism that is devised to overcome, as we have argued, the class abstraction problems created by numeric schemes. The numeric shape representation method used in conventional geometric modeling systems reveals difficulties in several aspects of architectural designing. Firstly, numeric schemes strongly require complete and detailed information for any simple task of object modeling. This requirement of information completeness makes it hard to apply numeric schemes to shapes in sketch level drawings that are characteristically ambiguous and have non-specific limitations on shape descriptions. Secondly, Cartesian coordinate-based quantitative shape representation schemes show restrictions in the task of shape comparison and classification that are inevitably involved in abstract concepts related to shape characteristics. One of the reasons why quantitative schemes are difficult to apply to the abstraction of individual shape information into its classes and categories is the uniqueness property, meaning that an individual description in a quantitative scheme should refer to only one object in the domain of representation. A class representation, however, should be able to indicate not only one but also a group of objects sharing common characteristics. Thirdly, it is difficult or inefficient to apply numeric shape representation schemes based on the Cartesian coordinate system to preliminary shape analysis and modeling tasks because of their emphasis on issues, such as detail, completeness, uniqueness and individuality, which can only be accessed in the final stages of designing. Therefore, we face the need for alternative shape representation schemes that can handle class representation of objects in order to manage the shapes in the early stages of designing. We consider shape as a boundary description consisting of a set of connected and closed lines. Moreover, we need to consider non-numeric approaches to overcome the problems caused by quantitative representation approaches.This paper introduces a qualitative approach to shape representation that is contrasted to conventional numeric techniques. This research is motivated by ideas and methodologies from related studies such as in qualitative formalism ([4], [6], [19], [13], [31]), qualitative abstraction [16], qualitative vector algebra ([7], [32]), qualitative shapes ([18], [23], [21]), and coding theory ([20], [25], [26], [1], [2], [3], [22]). We develop a qualitative shape representation scheme by adopting propitious aspects of the above techniques to suit the need for our shape comparison and analysis tasks. The qualitative shape-encoding scheme converts shapes into systematically constructed qualitative symbols called Q-codes. This paper explains how the Q-code scheme is developed and applied.

Incremental Geometric Modeling and Mask Synthesis for Surface Micromachined MEMS

2014 ◽  
Author(s):  
Jianhua Li ◽  
Hao Ling ◽  
Zhengchun Du
Keyword(s):  
Geometric Modeling ◽  
Process Model ◽  
Microelectromechanical Systems ◽  
Geometric Model ◽  
Test Results ◽  
Surface Micromachining ◽  
Modeling Methods ◽  
Variation Propagation ◽  
Mems Device ◽  
3D Geometric Model

In the design of surface micromachined microelectromechanical systems (MEMS), there is a lack of effective modeling methods to refine the geometry of a MEMS device. This paper presents a method of incremental geometric modeling and mask synthesis for surface micromachined MEMS. In this method, propagation-mapping graphs are introduced to label all the affected entities in one variation operation, according to the characteristic of surface micromachining. Based on the propagation-mapping graphs constructed from a 3D geometric model and its process model, variation propagation and mapping are used to update these models. In order to keep manufacturability of these models, four manufacturability problems caused by variation propagation are analyzed and a manufacturability maintenance method is discussed. Variation propagation and mapping achieve incremental modeling for the geometric model and process model of a MEMS device. This method enables designers to modify a MEMS device in a quick and intuitive way. Finally the method is implemented and some test results are given.

Geometric modeling of terry fabric

2015 ◽  
Vol 27 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Jitendra Pratap Singh ◽  
Bijoya Kumar Behera
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Structural Features ◽  
Geometrical Model ◽  
Content Type ◽  
Cad System ◽  
Actual Use ◽  
Actual Design ◽  
3D Geometric Model ◽  
First Time

Purpose – The purpose of this paper is to develop a 3D geometric model of three-pick terry fabric considering the actual design and structural features of the finished terry fabric. Design/methodology/approach – The model has been developed using SolidWorks CAD system and the output file can be easily simulated in the ANSYS. Dimensions are acquired from the actual terry fabric measurement. Findings – A 3D computational model – to be used for understanding the behaviour of terry fabric during actual use through the simulation in ANSYS. Practical implications – Provides the way to study the yarn and fabric structure behaviour during use through simulation. Originality/value – The research resulted a 3D geometrical model of very complex three-pick terry fabric for very first time for further analysis of terry fabric behaviour during use.

scholarly journals A graph-based method for fitting planar B-spline curves with intersections

2015 ◽  
Vol 3 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Pengbo Bo ◽  
Gongning Luo ◽  
Kuanquan Wang
Keyword(s):  
Shape Representation ◽  
Line Drawing ◽  
Weighted Graph ◽  
Point Clouds ◽  
Connected Components ◽  
Shape Information ◽  
B Spline ◽  
Spline Curves ◽  
Data Points ◽  
Shape Characteristics

Abstract The problem of fitting B-spline curves to planar point clouds is studied in this paper. A novel method is proposed to deal with the most challenging case where multiple intersecting curves or curves with self-intersection are necessary for shape representation. A method based on Delauney Triangulation of data points is developed to identify connected components which is also capable of removing outliers. A skeleton representation is utilized to represent the topological structure which is further used to create a weighted graph for deciding the merging of curve segments. Different to existing approaches which utilize local shape information near intersections, our method considers shape characteristics of curve segments in a larger scope and is thus capable of giving more satisfactory results. By fitting each group of data points with a B-spline curve, we solve the problems of curve structure reconstruction from point clouds, as well as the vectorization of simple line drawing images by drawing lines reconstruction.

Research on Virtual Plant Fruit Modeling Construction

2014 ◽  
Vol 926-930 ◽  
pp. 1738-1742
Author(s):  
Shan Hong Zhu ◽  
Jian Biao Chen
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Three Dimensional ◽  
Model Parameters ◽  
Fruit Morphology ◽  
Virtual Plant ◽  
Clear Sense ◽  
Modeling Approach

A geometric modeling approach based on ellipsoid Blinn algorithm is proposed to achieve simulation of three-dimensional visualization of plant fruit morphology. This paper proposes a geometric model and extracts the geometric model parameters which have clear sense of agronomy by observing common fruits such as potatoes, apples, watermelon, carambola and so on .The proposed approach has simple and intuitive features with vivid graphics realism and was implemented and applied to virtual plant fruits .

scholarly journals 3D Geometric Modeling of the Abu Madi Reservoirs and Its Implication on the Gas Development in Baltim Area (Offshore Nile Delta, Egypt)

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Mohamed I. Abdel-Fattah ◽  
Ahmed Y. Tawfik
Keyword(s):  
Geometric Modeling ◽  
Nile Delta ◽  
Geometric Model ◽  
Reservoir Volume ◽  
3D Effects ◽  
Interpretation Process ◽  
Reservoir Geometry ◽  
Gas Entrapment ◽  
Well Data ◽  
3D Geometric Model

3D geometric modeling has received renewed attention recently, in the context of visual scene understanding. The reservoir geometry of the Baltim fields is described by significant elements, such as thickness, depth maps, and fault planes, resulting from an interpretation based on seismic and well data. Uncertainties affect these elements throughout the entire interpretation process. They have some bearing on the geometric shape and subsequently on the gross reservoir volume (GRV) of the fields. This uncertainty on GRV also impacts volumes of hydrocarbons in place, reserves, and production profiles. Thus, the assessment of geometrical uncertainties is an essential first step in a field study for evaluation, development, and optimization purposes. Seismic data are best integrated with well and reservoir information. A 3D geometric model of the Late Messinian Abu Madi reservoirs in the time and depth domain is used to investigate the influence of the reservoir geometry on the gas entrapment. Important conceptual conclusions about the reservoir system behavior are obtained using this model. The results show that the reservoir shape influences the seismic response of the incised Abu Madi Paleovalley, making it necessary to account for 3D effects in order to obtain accurate results.

Hoist Sheave Structure Optimization and Lightweight

2015 ◽  
Vol 741 ◽  
pp. 133-137
Author(s):  
Xian Zhao Jia ◽  
Yong Fei Wang
Keyword(s):  
Working Condition ◽  
Geometric Model ◽  
Structure Optimization ◽  
Element Model ◽  
Stiffened Plate ◽  
Optimal Result ◽  
Ansys Software ◽  
Table Analysis ◽  
3D Geometric Model ◽  
Relational Table

To ensure wheel body of the hoisting sheave strength and stability condition. For the purpose of wheel body lightweighting. There are two schemes to reduce body weight.Reduce the spokes at the same time increase the ring stiffened plate, and reduce the spokes at the same time change the spokes width and thickness.The wheel body was established based on Pro/E 3D geometric model. Import the mesh in the Workbench of ANSYS software for finite element model. Statics analysis to select the optimized scheme. Establish a hoisting sheave wheel body under the actual working condition of widening the width - deformation - wheel weight relational table. Analysis to lightweight at the same time ensure that stiffness of wheel,then it can obtaine the optimal result.

scholarly journals The Method of High Accuracy Calculation of Robot Trajectory for the Complex Curves

2020 ◽  
Vol 28 (4) ◽  
pp. 247-252
Author(s):  
Alexander Lozhkin ◽  
Pavol Bozek ◽  
Konstantin Maiorov
Keyword(s):  
Calculation Method ◽  
Geometric Modeling ◽  
Classical Method ◽  
Geometric Model ◽  
New Method ◽  
Approximation Methods ◽  
Linear Transformations ◽  
Design Quality ◽  
Complex Curves ◽  
Internal Properties

AbstractThe geometric model accuracy is crucial for product design. More complex surfaces are represented by the approximation methods. On the contrary, the approximation methods reduce the design quality. A new alternative calculation method is proposed. The new method can calculate both conical sections and more complex curves. The researcher is able to get an analytical solution and not a sequence of points with the destruction of the object semantics. The new method is based on permutation and other symmetries and should have an origin in the internal properties of the space. The classical method consists of finding transformation parameters for symmetrical conic profiles, however a new procedure for parameters of linear transformations determination was acquired by another method. The main steps of the new method are theoretically presented in the paper. Since a double result is obtained in most stages, the new calculation method is easy to verify. Geometric modeling in the AutoCAD environment is shown briefly. The new calculation method can be used for most complex curves and linear transformations. Theoretical and practical researches are required additionally.

scholarly journals MODELING ARCHITECTURAL FORM SURFACE DEPENDENT SECTIONS

2021 ◽  
pp. 53-58
Author(s):  
A. A. Chekalin ◽  
M. K. Reshetnikov ◽  
V. V. Shpilev ◽  
S. V. Borodulina ◽  
S. A. Ryazanov
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Residential Building ◽  
Cubic Splines ◽  
Piecewise Smooth ◽  
Additional Parameter ◽  
Mathematical Apparatus ◽  
Surface Design ◽  
Fourth Degree ◽  
Architectural Form

For the design of surfaces in architecture, as a rule, universal techniques developed for other technical industries are used. First of all, these are general kinematic surfaces and interpolation cubic splines for modeling complex piecewise smooth surfaces. The authors propose to use the fourth degree inerodifferential spline developed by them for problems of geometric modeling of architectural forms. For calculations and constructions on a computer, the proposed spline is not much more complicated than traditional cubic splines, since it has one additional parameter - a coefficient. However, this allows you to locally control the shape of a curve or surface during design, that is, to change the shape in individual areas without affecting other areas. The article proposes a method for constructing a geometric model of the kinematic surface of dependent sections with a fourth degree parabola as a generator. When using cubic splines as a guide, the surface is a 3 × 4 non-uniform (heterogeneous) spline. The article shows that the surface on the basis of the proposed mathematical apparatus can be composite piecewise-smooth. A particular case of surface design is considered on the example of creating a model of the surface of the facade of a residential building according to the existing concept. The algorithm can be easily programmed and added as a tool to existing CAD systems.

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