268,724 research outputs found

    Method And Apparatus For Optically Digitizing A Three-dimensional Object

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    An apparatus and method for digitizing an object for creating a three-dimensional digital model of the object comprises a turntable for rotating the object about a rotation axis, at least first and second light sources positioned and oriented for directing a thin sheet of light toward the object along an illumination plane substantially parallel to and substantially intersecting with the rotation axis, a first detector positioned to one side of the illumination plane and oriented for detecting light reflected along a first detection plane from the object for creating a plurality of first side contours as the object rotates, a second detector positioned to a side of the illumination plane, opposite the one side, for detecting light reflected along a second detection plane from the object for creating a plurality of second side contours as the object rotates, a third detector for capturing illumination on-axis contours in the form of a vertical straight line to derive an instantaneous color of the object's surface as a function of the height of the object, and a combining and evaluating computer for combining the first side contours, the second side contours, and the illumination on-axis contours for generating a plurality of composite contours and for evaluating the composite contours for creating a three-dimensional digital model of the object.Georgia Tech Research Corporatio

    Teaching kinematics and dynamics of multibody mechanical systems using the object oriented language modelica

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    A new modeling language, called Modelica, for physical modeling is being developed in an international effort. The main objective is to make it easy to exchange models and model libraries for different domains, such as, mechanical, pneumatics, electrical, hydraulics, and others. The design approach builds on non-causal modeling with true ordinary differential and algebraic equations and the use of object-oriented constructs stemming from modern software development, (hierarchy, encapsulation) to facilitate reuse of models and model parts. This paper gives an overview of the use of the object oriented language Modelica with the mechanical Multibody Library to model and simulate three-dimensional mechanical systems

    Three Dimensional Software Modelling

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    Traditionally, diagrams used in software systems modelling have been two dimensional (2D). This is probably because graphical notations, such as those used in object-oriented and structured systems modelling, draw upon the topological graph metaphor, which, at its basic form, receives little benefit from three dimensional (3D) rendering. This paper presents a series of 3D graphical notations demonstrating effective use of the third dimension in modelling. This is done by e.g., connecting several graphs together, or in using the Z co-ordinate to show special kinds of edges. Each notation combines several familiar 2D diagrams, which can be reproduced from 2D projections of the 3D model. 3D models are useful even in the absence of a powerful graphical workstation: even 2D stereoscopic projections can expose more information than a plain planar diagram

    The development and validation of the object-oriented quasi three-dimensional regional groundwater model ZOOMQ3D

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    This report documents the modifications made to the object-oriented regional groundwater model ZOOM2D (The University of Birmingham, 2001). Additional mechanisms are introduced to this model to satisfy the generally-accepted functional requirements of a commonly-applied regional groundwater flow model. The modified model, ZOOMQ3D, is quasi three-dimensional and is validated through comparison with analytical solutions and with instructional problems formulated for MODFLOW (McDonald and Harbaugh, 1988) by Anderson (1993)

    Beam Dynamics in High Intensity Cyclotrons Including Neighboring Bunch Effects: Model, Implementation and Application

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    Space charge effects, being one of the most significant collective effects, play an important role in high intensity cyclotrons. However, for cyclotrons with small turn separation, other existing effects are of equal importance. Interactions of radially neighboring bunches are also present, but their combined effects has not yet been investigated in any great detail. In this paper, a new particle in cell based self-consistent numerical simulation model is presented for the first time. The model covers neighboring bunch effects and is implemented in the three-dimensional object-oriented parallel code OPAL-cycl, a flavor of the OPAL framework. We discuss this model together with its implementation and validation. Simulation results are presented from the PSI 590 MeV Ring Cyclotron in the context of the ongoing high intensity upgrade program, which aims to provide a beam power of 1.8 MW (CW) at the target destination

    An Object-Oriented Approach for Temporal Data

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    There is a growing need for easier access to temporal data. Recent developments of object-oriented data models represent the most promising approach to modeling complex aspects of the real world. Here, we present an object-oriented data model for supporting the storage and access of temporal information. The model consists of two parts. In the first part, we present the definition of a class for time object. The class is general enough so that it can be applied for various applications. Another part of the data model integrates time objects with entity objects and their attributes by following the pervasive three-dimensional metaphor of time. Particularly, the model incorporates with object-oriented technique all the three primary dimensions, which are time, entity, and attribute, of the metaphor

    Object oriented programming : data preparation and visualization of FEM models

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    In this paper two object oriented applications are described. The former is intended to generate data associated with the finite element method (FEM) and the later is a three-dimensional visualization tool named 3DMesh. Both are based on the principles of object oriented programming, namely encapsulation, inheritance and polymorphism. To support the preparation of FEM data, a language named 3DO was developed. Its syntax is similar to a subset of the C++ programming language. 3DO is based on object construction and modification by methods that require a small number of arguments. With this tool, mesh generation, definition of properties and loads and mesh refinement can be performed with limited user effort, even when the model is complex. All the generated information can be visualized with the program 3DMesh. This application is based on the OpenGL library and uses the Microsoft Foundation Classes to simplify its integration in the MS-Windows environment. 3DMesh implements an interactive navigation technique that allows the visualization of the model interior, preserving its integrity. Model attributes and the results of the FEM analysis can also be visualized

    Interactive Visualization of the Building of University of Economics – Varna via 3D Modeling

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    The object of this paper is presenting the University of Economics – Varna, using a 3D model with 3Ds MAX. Created in 1920, May 14, University of Economics - Varna is a cultural institution with a place and style of its own. With the emergence of the three-dimensional modeling we entered a new stage of the evolution of computer graphics. The main target is to preserve the historical vision, to demonstrate forward-thinking and using of future-oriented approaches

    Spherical Radiative Transfer in C++ (SRTC++): A Parallel Monte-Carlo Radiative Transfer Model for Titan

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    We present a new computer program, SRTC++, to solve spatial problems associated with explorations of Saturn’s moon Titan. The program implements a three-dimensional structure well-suited to addressing shortcomings arising from plane-parallel radiative transfer approaches. SRTC++’s design uses parallel processing in an object-oriented, compiled computer language (C++) leading to a flexible and fast architecture. We validate SRTC++ using analytical results, semianalytical radiative transfer expressions, and an existing Titan plane-parallel model. SRTC++ complements existing approaches, addressing spatial problems like near-limb and near-terminator geometries, non-Lambertian surface phase functions (including specular reflections), and surface albedo nonuniformity
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