A Computational Approach to the Reconstruction of Surface Geometry from Early Temple Superstructures

2005 ◽  
Vol 3 (4) ◽  
pp. 471-486 ◽  
Author(s):  
Sambit Datta ◽  
David Beynon
Keyword(s):  
Field Measurements ◽  
Computational Approach ◽  
Computational Techniques ◽  
Western India ◽  
Parametric Modelling ◽  
Surface Geometry ◽  
Rule Based ◽  
Geometry Model ◽  
Implicit Geometry ◽  
Canonical Texts

Recovering the control or implicit geometry underlying temple architecture requires bringing together fragments of evidence from field measurements, relating these to mathematical and geometric descriptions in canonical texts and proposing “best-fit” constructive models. While scholars in the field have traditionally used manual methods, the innovative application of niche computational techniques can help extend the study of artefact geometry. This paper demonstrates the application of a hybrid computational approach to the problem of recovering the surface geometry of early temple superstructures. The approach combines field measurements of temples, close-range architectural photogrammetry, rule-based generation and parametric modelling. The computing of surface geometry comprises a rule-based global model governing the overall form of the superstructure, several local models for individual motifs using photogrammetry and an intermediate geometry model that combines the two. To explain the technique and the different models, the paper examines an illustrative example of surface geometry reconstruction based on studies undertaken on a tenth century stone superstructure from western India. The example demonstrates that a combination of computational methods yields sophisticated models of the constructive geometry underlying temple form and that these digital artefacts can form the basis for in depth comparative analysis of temples, arising out of similar techniques, spread over geography, culture and time.

scholarly journals A Surface Geometry Model for LiDAR Depth Completion

2021 ◽  
pp. 1-1
Author(s):  
Yiming Zhao ◽  
Lin Bai ◽  
Ziming Zhang ◽  
Xinming Huang
Keyword(s):  
Surface Geometry ◽  
Geometry Model

Distributed-Parameter Modeling for Geometry Control of Manufacturing Processes With Material Deposition

1998 ◽  
Vol 122 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Charalabos Doumanidis ◽  
Eleni Skordeli
Keyword(s):  
Solid Freeform Fabrication ◽  
Surface Topology ◽  
Distributed Parameter ◽  
Surface Geometry ◽  
Mass Source ◽  
Freeform Fabrication ◽  
Geometry Model ◽  
Material Deposition ◽  
Solid Objects ◽  
3D Solid

Recent solid freeform fabrication methods generate 3D solid objects by material deposition in successive layers made of adjacent beads. Besides numerical simulation, this article introduces an analytical model of such material addition, using superposition of unit deposition distributions, composed of elementary spherical primitives consistent with the mass transfer physics. This real-time surface geometry model, with its parameters identified by in-process profile measurements, is used for Smith-prediction of the material shape in the unobservable deposition region. The model offers the basis for a distributed-parameter geometry control scheme to obtain a desired surface topology, by modulating the feed and motion of a moving mass source. The model was experimentally tested on a fused wire deposition welding station, using optical sensing by a scanning laser stripe. Its applications to other rapid prototyping methods are discussed. [S0022-0434(00)02301-7]

The Impact of Hardened Steel Milling Surface Structure on Mould Service Load

2014 ◽  
Vol 800-801 ◽  
pp. 342-347
Author(s):  
Min Li Zheng ◽  
Jin Hui Xu ◽  
Wei Zhang ◽  
Zhao Xing Zhang ◽  
Tong Wu
Keyword(s):  
Hardened Steel ◽  
Surface Load ◽  
Surface Geometry ◽  
Surface Loading ◽  
Machined Surface ◽  
Geometry Model ◽  
Geometry Structure ◽  
Mould Surface ◽  
Service Load ◽  
The Impact

Mould surface loading state is one of the most important factors which would affect the mould performance in the course of service. According to the established hardened steel milling surface geometry model, a bending forming numerical simulation of hardened steel milling is conducted, the influence law of service process surface load state is analyzed under machined surface geometry structure which is formed by different milling parameters. The research results show: surface load concentrated area is mainly focusing on mould edge transition and fillet in the course of service; the surface geometry structure has an important influence on the mould service load in the course of service, service load more smaller which is more helpful to improve the mould service performance in the course of service.

What connectionist models learn: Learning and representation in connectionist networks

1990 ◽  
Vol 13 (3) ◽  
pp. 471-489 ◽  
Author(s):  
Stephen José Hanson ◽  
David J. Burr
Keyword(s):  
Computational Approach ◽  
Complex Interaction ◽  
Connectionist Models ◽  
Promising Alternative ◽  
Rule Based ◽  
Symbol Processing ◽  
Connectionist Networks ◽  
Connectionist Approach ◽  
The Brain ◽  
Explicit Rule

AbstractConnectionist models provide a promising alternative to the traditional computational approach that has for several decades dominated cognitive science and artificial intelligence, although the nature of connectionist models and their relation to symbol processing remains controversial. Connectionist models can be characterized by three general computational features: distinct layers of interconnected units, recursive rules for updating the strengths of the connections during learning, and “simple” homogeneous computing elements. Using just these three features one can construct surprisingly elegant and powerful models of memory, perception, motor control, categorization, and reasoning. What makes the connectionist approach unique is not its variety of representational possibilities (including “distributed representations”) or its departure from explicit rule-based models, or even its preoccupation with the brain metaphor. Rather, it is that connectionist models can be used to explore systematically the complex interaction between learning and representation, as we try to demonstrate through the analysis of several large networks.

Fluid-Structure Interaction Simulations of Parachute Deployment and Inflation

2021 ◽  
Author(s):  
Liwu Wang ◽  
Mingzhang Tang ◽  
Yu Liu ◽  
Sijun Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Structure Interaction ◽  
Computational Approach ◽  
Computational Techniques ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Structure Dynamics ◽  
Computational Structure ◽  
Membrane Wrinkling

Abstract The numerical simulation of the parachute deployment/inflation process involves fluid structure interaction problems, the inherent complexities in the fluid structure interaction have been posing several computational challenges. In this paper a high fidelity Eulerian computational approach is proposed for the simulation of parachute deployment/inflation. Unlike the arbitrary Eulerian Lagrangian (ALE) method widely employed in this area, the Eulerian computational approach is established on three computational techniques: computational fluid dynamics, computational structure dynamics and computational moving boundary. A set of stationary, non-deforming Cartesian grids is adopted in our computational fluid dynamics, our computational structure dynamics is enhanced by non-linear finite element method and membrane wrinkling algorithm, instead of conventional computational mesh dynamics, an immersed boundary method is employed to avoid insurmountable poor grid quality brought in by moving mesh approaches. To validate the proposed numerical approach the deployment/inflation of C-9 parachute is simulated using our approach and the results show similar characteristics compared with experimental results and previous literature. The computed results have demonstrated the proposed method to be a useful tool for analyzing dynamic parachute deployment and subsequent inflation.

Computational Modeling of Turbulent Flows Over Rough Surfaces

2003 ◽  
Author(s):  
Gocha Chochua ◽  
Wei Shyy
Keyword(s):  
Turbulent Flows ◽  
Large Scale ◽  
Rough Surfaces ◽  
Computational Cost ◽  
The Other ◽  
Computational Techniques ◽  
Engineering Model ◽  
Surface Geometry ◽  
Roughness Lengths ◽  
Scale Roughness

Turbulent flows over rough surfaces are often encountered in nature and engineering practices and are often difficult to analyze. In this study, combined modeling and computational techniques is involved to investigate such flows over a surface covered with a large-scale roughness pattern. A simplified empirical engineering model is validated by taking area average of the flow field data over the surface. The approach can interpret fluid physics based on the empirical correlation. The area-averaged mean momentum transport resulting from the wall-normal time-averaged velocity component is found to be a significant contributing term into the near-boundary shear stress balance. This makes its behavior different from the flow over a smooth surface. Comparing alternative approaches for estimating the roughness coefficients, it is found that the mass-flow-rate-deficit approach produces superior results. Flow in a channel with one wall covered with an array of cylindrical cavities and the other smooth is used as an example. The extended wall functions, based on the k-ε closure and the simplified engineering model, can be applied for a large-scale roughness pattern. The approach can significantly reduce required computational cost. On the other hand, the small domain periodic computations are needed to produce roughness lengths for a particular surface geometry. This model can develop a general correlation relating the roughness lengths to a surface geometry to aid engineering design.

In-Cylinder Tumble Flow Field Measurements and Predictions

1999 ◽  
Vol 123 (1) ◽  
pp. 139-145 ◽  
Author(s):  
C.-W. Hong ◽  
S.-D. Tarng
Keyword(s):  
Flow Field ◽  
Field Measurements ◽  
Laser Doppler Velocimeter ◽  
Computational Techniques ◽  
Plastic Tube ◽  
Stationary Turbulence ◽  
Flow Test ◽  
Cylinder Flow ◽  
Recent Version ◽  
Level Of Agreement

This paper presents the comparison between measured and predicted results of the in-cylinder tumble flow generated by a port-valve-liner assembly on a steady-flow test bench. The purpose was to advance the understanding of the stationary turbulence process via experimental and computational techniques in the same time. A baseline single-cylinder 4-stroke motorcycle engine was chosen. Its liner was replaced by a transparent acrylic-plastic tube and the piston was removed. This was to focus the research on the tumble flow generated by the geometry of its port, the passage of the canted inlet valve, and a dome-shaped combustion chamber. The in-cylinder turbulent flow field was measured via a 3-component laser Doppler velocimeter (LDV) point by point. A simultaneous computer simulation was carried out to predict the in-cylinder flow field of the same engine under the same operating condition, using KIVA3V—the most recent version of the KIVA code. The mean speed, turbulence intensity, tumble ratio, swirl ratio, and vortex circulation from both skills were all compared. A reasonably good level of agreement has been achieved. Both modern techniques are also validated.

scholarly journals Processors and Processes: Exploring Computational Design and Landscape Architecture

2021 ◽  
Author(s):  
◽  
Philip Belesky
Keyword(s):  
Design Process ◽  
Landscape Architecture ◽  
Computational Design ◽  
Ecological Systems ◽  
Computational Approach ◽  
Computational Techniques ◽  
Concept Design ◽  
Computational Tools ◽  
Industrial Landscape ◽  
Post Industrial

<p>The computer can be a highly efficient drafting table. It can also be much more. Architects can use programming to engage with the computer on its own terms, and in doing so gain a better understanding of complex geometric, structural, or conceptual design scenarios. This ‘computational approach’ to design is increasingly common in architecture, but comparatively rare within landscape architecture. In this thesis I examine how and why landscape architects might employ computational design.  I start by reviewing the work of computational architects and landscape urbanists. I identify that both emphasize diagrammatic and processual strategies as a means to confront complexity and indeterminism within the design process. However, this conceptual overlap masks a technological divergence, as computational tools are presently ill-suited to the needs of landscape architects. Their focus should be shifted away from formal exploration and towards the analysis, simulation, and generation of landscape systems. Doing so would offer landscape architects new forms of representation that would overcome some of the current limitations within their design process.  To test this proposition, I create a series of generative tools, or ‘patterns’, that use computational techniques to model ecological systems. This pattern-based approach introduces a methodology that improves the accessibility and flexibility of computational design. These patterns are applied in tandem with standard computational techniques to create a concept design for a post-industrial landscape. Through this research I identify computation as a powerful tool for designing landscapes. The conceptual and technical methodologies it offers enable landscape architects to better understand and explore open-ended and indeterminate systems. Computation offers a novel opportunity to combine conceptual openness and technical rigour when designing complex landscapes.</p>

scholarly journals EXPERIMENTAL AND NUMERICAL STUDY OF CONTROLLED FLUTTER TESTING IN A LINEAR TURBINE BLADE CASCADE

2018 ◽  
Vol 20 ◽  
pp. 98-107
Author(s):  
Václav Sláma ◽  
Bartoloměj Rudas ◽  
Petr Eret ◽  
Volodymyr Tsymbalyuk ◽  
Jiří Ira ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Turbine Blade ◽  
Numerical Study ◽  
Experimental Testing ◽  
Turbine Blades ◽  
Numerical Approach ◽  
Travelling Wave ◽  
Wave Mode ◽  
Computational Techniques ◽  
Geometry Model

In this paper, experimental testing of flutter and numerical simulations using a commercial code ANSYS CFX and an in-house code TRAF are performed on an oscillating linear cascade of turbine blades installed in a subsonic test rig. Bending and torsional motions of the blades are investigated in a travelling wave mode approach. In each numerical approach, a rig geometry model with a different level of complexity is used. Good agreement between the numerical simulations and experiments is achieved using both approaches and benefits and drawbacks of each technique are commented in this paper. It is demonstrated that both used computational techniques are adequate to predict turbine blade flutter. It is concluded that validated numerical tools can provide a better insight of flutter phenomena of operationally flexible steam turbine last stage blades.

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