Search NASA⌕ Search

SEARCH · Search NASA

Results for “cartogram”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Operational Efficiency Evaluation of a Setup for Removing Stresses in the Steam Header of PGV-1000 Steam Generator

The effectiveness of a setup for removing stresses in the steam header of a PGV-1000 steam generator is evaluated. The evaluation is based on an investigation of the stress state by means of magnetic anisotropy measurements performed in the zone of the No. 111 weld seam of the hot header of steam generators operating in one of the power-generating units with a V-320 series reactor arrangement. Inspections made it possible to obtain cartograms of the distribution of the difference of the principal mechanical stresses along the perimeter of the weld connection of a PGV-1000 header equipped with a cooling mantle and headers without such a mantle. By means of statistical analysis of the data, a diagram of the distribution of the principal mechanical stresses was obtained. In addition, the distribution of the standard deviation of the principal mechanical stresses as a measure of the dispersion of a random quantity relative to its mathematical expectation was determined.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Volumetric Density-Equalizing Reference Map with Applications

The density-equalizing map, a technique developed for cartogram creation, has been widely applied to data visualization but only for 2D applications. Here, we propose a novel method called the volumetric density-equalizing reference map (VDERM) for computing density-equalizing map for volumetric domains. Given a prescribed density distribution in a volumetric domain in $\mathbb{R}^3$, the proposed method continuously deforms the domain, with different volume elements enlarged or shrunk according to the density distribution. With the aid of the proposed method, medical and sociological data can be visualized via deformations of 3D objects. The method can also be applied to adaptive remeshing and shape modeling. Furthermore, by exploiting the time-dependent nature of the proposed method, applications to shape morphing can be easily achieved. Experimental results are presented to demonstrate the effectiveness of the proposed method.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Density-Equalizing Maps for Simply Connected Open Surfaces

Here in this paper, we are concerned with the problem of creating flattening maps of simply connected open surfaces in $\mathbb{R}^3$. Using a natural principle of density diffusion in physics, we propose an effective algorithm for computing density-equalizing maps with any prescribed density distribution. By varying the initial density distribution, a large variety of flattening maps with different properties can be achieved. For instance, area-preserving parameterizations of simply connected open surfaces can be easily computed. Experimental results are presented to demonstrate the effectiveness of our proposed method. Applications to data visualization and surface remeshing are explored.

97 MATHEMATICS AND COMPUTING↗