THREE-DIMENSIONAL GEOMETRIC MODELING OF THRUST DUPLEX IN THE FEURA BUSH QUARRY, SELKIRK, NY USING STRUCTURE FROM MOTION (SFM)

2019 ◽  
Author(s):  
Pragnyadipta Sen ◽  
◽  
Veronica F. Sullivan ◽  
Rebecca Fildes
Keyword(s):  
Structure From Motion ◽  
Geometric Modeling ◽  
Three Dimensional

Encoding of three-dimensional structure-from-motion by primate area MT neurons

Nature ◽  
10.1038/33688 ◽  
1998 ◽  
Vol 392 (6677) ◽  
pp. 714-717 ◽  
Author(s):  
David C. Bradley ◽  
Grace C. Chang ◽  
Richard A. Andersen
Keyword(s):  
Structure From Motion ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Area Mt ◽  
Three Dimensional Structure ◽  
Mt Neurons

Inferring Structure from Motion in Two-View and Multiview Displays

Perception ◽  
1993 ◽  
Vol 22 (12) ◽  
pp. 1441-1465 ◽  
Author(s):  
Jeffrey C Liter ◽  
Myron L Braunstein ◽  
Donald D Hoffman
Keyword(s):  
Relative Motion ◽  
Apparent Motion ◽  
Structure From Motion ◽  
Three Dimensional ◽  
Rigid Motion ◽  
Parameter Family ◽  
Image Motion ◽  
Heuristic Analysis

Five experiments were conducted to examine constraints used to interpret structure-from-motion displays. Theoretically, two orthographic views of four or more points in rigid motion yield a one-parameter family of rigid three-dimensional (3-D) interpretations. Additional views yield a unique rigid interpretation. Subjects viewed two-view and thirty-view displays of five-point objects in apparent motion. The subjects selected the best 3-D interpretation from a set of 89 compatible alternatives (experiments 1–3) or judged depth directly (experiment 4). In both cases the judged depth increased when relative image motion increased, even when the increased motion was due to increased simulation rotation. Subjects also judged rotation to be greater when either simulated depth or simulated rotation increased (experiment 4). The results are consistent with a heuristic analysis in which perceived depth is determined by relative motion.

Advances in FEMN: The Code for Nuclear Noise Analysis Based on ICEM-CFD

2018 ◽  
Author(s):  
Baoxin Yuan ◽  
Herong Zeng ◽  
Wankui Yang ◽  
Songbao Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometric Modeling ◽  
Noise Analysis ◽  
Three Dimensional ◽  
Noise Spectrum ◽  
Benchmark Problem ◽  
Reactor Physics ◽  
Icem Cfd ◽  
Element Method

The finite element method based on unstructured mesh has good geometry adaptability, it has been used to solve reactor physics problems, manual description of geometric modeling and meshing makes the current finite element code very complicated, it greatly restricts the application of this method in the numerical calculation of reactor physics. Using the CAD pre-processing software ICEM-CFD, three dimensional geometry is divided into tetrahedral or hexahedral meshes, two dimensional geometry is divided into triangular or quadrilateral meshes, the main code of neutron calculation for nuclear noise analysis based on finite element method is developed. The steady state parameters are calculated and tested through benchmark problem, the test results show that the code has the corresponding computing capabilities. Finally, the neutron noise spectrum is calculated for the 3D PWR benchmark problem published by IAEA, and the noise distribution under given frequency is given.

scholarly journals REPRESENTATION AND DIGITALIZATION OF STONE THEATRES IN EASTERN SICILY: THE PALAZZOLO ACREIDE THEATER

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 475-479
Author(s):  
G. Di Gregorio
Keyword(s):  
Structure From Motion ◽  
3D Model ◽  
Southern Italy ◽  
Three Dimensional ◽  
Cultural Value ◽  
Geometric Conditions ◽  
Dense Matching ◽  
Laser Scanners ◽  
First Results ◽  
Quality And Reliability

<p><strong>Abstract.</strong> The ancient theatres in Sicily, in southern Italy and along the countries facing the Mediterranean Sea basin, constitute a reality of incomparable cultural value. Regarding the research on the ancient theatres of eastern Sicily, few studies have been recently dealt with different methodologies. In the last years some practices have been done using 3D laser scanners for the theatres of Syracuse, Taormina and Morgantina, as well as the Syracuse amphitheatre and Taormina Odeon, just obtaining very interesting results. Lately the theatre of Palazzolo Acreide (Syracuse) has been studied, with Structure From Motion (SFM) and Dense Matching methodologies. From these experience, conclusions could be drawn on the quality and reliability of the elaborations realised with the SFM methodologies. We really know that these systems are today representing one of the fastest growing areas of examination, on which several software houses are investing. The study was chosen both for the small size of the building, and for the particular geometric conditions typical of the architecture of ancient theatres. This because their three-dimensional trend varies continually in the three variables X, Y, Z. The purpose of the work was to check whether the latest releases of these systems of survey allow today more than yesterday, a rapid digitalization and representation of the enormous archaeological cultural heritage. Various software were used, to verify the practicality and operation, the choice then fell on the Zephyr of 3DFlow, kindly available by the manufacturer, whose results were quite agreeable. The possibility offered by the program of a graphical tracing of polylines on the textured 3D model, has been a considerable advantage. Therefore the results obtained by modeling and surveying of the Palazzolo Acreide theatre have been compared, with the survey of the Syracuse, Taormina and Morgantina theatre performed using 3D laser scanners. First results of the research are matter of the following work.</p>

scholarly journals ACCURACY ASSESSMENT IN STRUCTURE FROM MOTION 3D RECONSTRUCTION FROM UAV-BORN IMAGES: THE INFLUENCE OF THE DATA PROCESSING METHODS

2015 ◽  
Vol XL-1/W4 ◽  
pp. 103-109 ◽  
Author(s):  
G. Caroti ◽  
I. Martínez-Espejo Zaragoza ◽  
A. Piemonte
Keyword(s):  
Data Processing ◽  
Structure From Motion ◽  
Laser Scanning ◽  
Accuracy Assessment ◽  
Three Dimensional ◽  
Evolution Of Structure ◽  
Textured Models ◽  
The Church ◽  
Data Processing Methods

The evolution of Structure from Motion (SfM) techniques and their integration with the established procedures of classic stereoscopic photogrammetric survey have provided a very effective tool for the production of three-dimensional textured models. Such models are not only aesthetically pleasing but can also contain metric information, the quality of which depends on both survey type and applied processing methodologies. An open research topic in this area refers to checking attainable accuracy levels. The knowledge of such accuracy is essential, especially in the integration of models obtained through SfM with other models derived from different sensors or methods (laser scanning, classic photogrammetry ...). Accuracy checks may be conducted by either comparing SfM models against a reference one or measuring the deviation of control points identified on models and measured with classic topographic instrumentation and methodologies. This paper presents an analysis of attainable accuracy levels, according to different approaches of survey and data processing. For this purpose, a survey of the Church of San Miniato in Marcianella (Pisa, Italy), has been used. The dataset is an integration of laser scanning with terrestrial and UAV-borne photogrammetric surveys; in addition, a high precision topographic network was established for the specific purpose. In particular, laser scanning has been used for the interior and the exterior of the church, with the exclusion of the roof, while UAVs have been used for the photogrammetric survey of both roof, with horizontal strips, and façade, with vertical strips.

Geometric Modeling and Simulation of Mechanical Assemblies With Elastic Components

1994 ◽  
Author(s):  
Yong Fang ◽  
F. W. Liou
Keyword(s):  
Finite Element Method ◽  
Geometric Modeling ◽  
Three Dimensional ◽  
Elastic Behavior ◽  
Elastic Analysis ◽  
Simulation Tool ◽  
Body System ◽  
Mechanical Assembly ◽  
Mechanical Assemblies ◽  
Multi Body

Abstract In this paper, the implementation of a modeling system for the simulation of three dimensional mechanical assemblies with elastic components is presented. A mechanical assembly is modeled as a multi-body system with changing topologies. The elastic behavior can be automatically modeled using finite element method. With this simulation tool, a designer can interactively create an assembly of mechanical components ready for dynamic and elastic analysis. This paper presents a prototype of the modeling system.

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