scholarly journals Targeted covariance inflation for 3D‐volume radar reflectivity assimilation with the LETKF

2021 ◽  
Author(s):  
Klaus Vobig ◽  
Klaus Stephan ◽  
Ulrich Blahak ◽  
Kobra Khosravian ◽  
Roland Potthast
Keyword(s):  
Radar Reflectivity ◽  
3D Volume

1712: Predictive Value of 3D Volume Rendered CT for Collecting System Entry Prior to Nephron Sparing Surgery

2005 ◽  
Vol 173 (4S) ◽  
pp. 464-464
Author(s):  
Ithaar H. Derweesh ◽  
Gaspar A. Motta-Ramirez ◽  
Mahesh Gael ◽  
Nancy Obuchowski ◽  
Hazem A. Moneim ◽  
...  
Keyword(s):  
Predictive Value ◽  
Nephron Sparing Surgery ◽  
Nephron Sparing ◽  
3D Volume ◽  
Collecting System

A spontán mellkasfali sérvekről két operált eset kapcsán

2010 ◽  
Vol 63 (2) ◽  
pp. 80-83 ◽  
Author(s):  
Károly Vincze ◽  
Péter Zádori ◽  
Zsolt Magyaródi ◽  
Gyula Horváth
Keyword(s):  
Volume Rendering ◽  
Spiral Ct ◽  
Multislice Spiral Ct ◽  
3D Volume ◽  
3D Volume Rendering

Absztrakt A szerzők a világirodalmi ritkaságnak számító atraumaticus (spontán) mellkasfali tüdősérvet ismertetik. Két operált betegük kapcsán bemutatják a sérv kialakulását elősegítő körülményeket és a kórkép klinikai jellemzőit. Mindkét betegük spontán mellkasfali (intercostalis) sérvét chronicus obstructiv syndroma (COPD) okozta makacs köhögés váltotta ki. Az elvégzett multislice spirál CT (MSCT) vizsgálat, valamint a speciális szoftver segítségével készített másodlagos 3D „volume-rendering” (VRT) rekonstrukciós képek egyértelműen utaltak a ritka kórformára. Az MSCT-vizsgálatok a Kaposi Mór Oktató Kórházban készültek, Siemens Somatom Emotion 6 MSCT-berendezéssel. A pontos diagnózis birtokában végzett mellkasfali korrekciók tartós gyógyuláshoz vezettek. A szerzők röviden ismertetik a mellkasfali sérvekkel kapcsolatos hazai és fontosabb külföldi irodalmi vonatkozásokat. A kórkép rendkívüli ritkasága ellenére a kialakulásában szerepet játszó COPD elterjedtsége miatt érdemel figyelmet. A hasonló esetek diagnosztikájában nagy segítséget jelenthet a bemutatott korszerű képalkotó eljárás alkalmazása.

scholarly journals Interactive 3D volume rendering in biomedical publications

Micron ◽  
2010 ◽  
Vol 41 (7) ◽  
pp. 886.e1-886.e17 ◽  
Author(s):  
Bernhard Ruthensteiner ◽  
Natalie Baeumler ◽  
David G. Barnes
Keyword(s):  
Volume Rendering ◽  
Interactive 3D ◽  
Biomedical Publications ◽  
3D Volume ◽  
3D Volume Rendering

scholarly journals Effect of the Assimilation Frequency of Radar Reflectivity on Rain Storm Prediction by Using WRF-3DVAR

2021 ◽  
Vol 13 (11) ◽  
pp. 2103
Author(s):  
Yuchen Liu ◽  
Jia Liu ◽  
Chuanzhe Li ◽  
Fuliang Yu ◽  
Wei Wang
Keyword(s):  
Data Assimilation ◽  
Northern China ◽  
Horizontal Resolution ◽  
Radar Reflectivity ◽  
Small Scale ◽  
Time Interval ◽  
Outer Domain ◽  
Storm Prediction ◽  
The Impact ◽  
Assimilation Time

An attempt was made to evaluate the impact of assimilating Doppler Weather Radar (DWR) reflectivity together with Global Telecommunication System (GTS) data in the three-dimensional variational data assimilation (3DVAR) system of the Weather Research Forecast (WRF) model on rain storm prediction in Daqinghe basin of northern China. The aim of this study was to explore the potential effects of data assimilation frequency and to evaluate the outputs from different domain resolutions in improving the meso-scale NWP rainfall products. In this study, four numerical experiments (no assimilation, 1 and 6 h assimilation time interval with DWR and GTS at 1 km horizontal resolution, 6 h assimilation time interval with radar reflectivity, and GTS data at 3 km horizontal resolution) are carried out to evaluate the impact of data assimilation on prediction of convective rain storms. The results show that the assimilation of radar reflectivity and GTS data collectively enhanced the performance of the WRF-3DVAR system over the Beijing-Tianjin-Hebei region of northern China. It is indicated by the experimental results that the rapid update assimilation has a positive impact on the prediction of the location, tendency, and development of rain storms associated with the study area. In order to explore the influence of data assimilation in the outer domain on the output of the inner domain, the rainfall outputs of 3 and 1 km resolution are compared. The results show that the data assimilation in the outer domain has a positive effect on the output of the inner domain. Since the 3DVAR system is able to analyze certain small-scale and convective-scale features through the incorporation of radar observations, hourly assimilation time interval does not always significantly improve precipitation forecasts because of the inaccurate radar reflectivity observations. Therefore, before data assimilation, the validity of assimilation data should be judged as far as possible in advance, which can not only improve the prediction accuracy, but also improve the assimilation efficiency.

scholarly journals 3D sub-nanometer analysis of glucose in an aqueous solution by cryo-atom probe tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. M. Schwarz ◽  
C. A. Dietrich ◽  
J. Ott ◽  
E. M. Weikum ◽  
R. Lawitzki ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Density Functional ◽  
Chemical Characterization ◽  
Analytical Techniques ◽  
Atom Probe ◽  
Characterization Methods ◽  
Signal Deconvolution ◽  
The Stability ◽  
Frozen Solutions ◽  
3D Volume

AbstractAtom Probe Tomography (APT) is currently a well-established technique to analyse the composition of solid materials including metals, semiconductors and ceramics with up to near-atomic resolution. Using an aqueous glucose solution, we now extended the technique to frozen solutions. While the mass signals of the common glucose fragments CxHy and CxOyHz overlap with (H2O)nH from water, we achieved stoichiometrically correct values via signal deconvolution. Density functional theory (DFT) calculations were performed to investigate the stability of the detected pyranose fragments. This paper demonstrates APT’s capabilities to achieve sub-nanometre resolution in tracing whole glucose molecules in a frozen solution by using cryogenic workflows. We use a solution of defined concentration to investigate the chemical resolution capabilities as a step toward the measurement of biological molecules. Due to the evaporation of nearly intact glucose molecules, their position within the measured 3D volume of the solution can be determined with sub-nanometre resolution. Our analyses take analytical techniques to a new level, since chemical characterization methods for cryogenically-frozen solutions or biological materials are limited.

scholarly journals Computational Geometry-Based Surface Reconstruction for Volume Estimation: A Case Study on Magnitude-Frequency Relations for a LiDAR-Derived Rockfall Inventory

2021 ◽  
Vol 10 (3) ◽  
pp. 157
Author(s):  
Paul-Mark DiFrancesco ◽  
David A. Bonneau ◽  
D. Jean Hutchinson
Keyword(s):  
Computational Geometry ◽  
Surface Reconstruction ◽  
Power Law ◽  
Point Cloud ◽  
Point Clouds ◽  
Volume Estimation ◽  
Estimation Methods ◽  
Small Scale ◽  
Reconstruction Methods ◽  
3D Volume

Key to the quantification of rockfall hazard is an understanding of its magnitude-frequency behaviour. Remote sensing has allowed for the accurate observation of rockfall activity, with methods being developed for digitally assembling the monitored occurrences into a rockfall database. A prevalent challenge is the quantification of rockfall volume, whilst fully considering the 3D information stored in each of the extracted rockfall point clouds. Surface reconstruction is utilized to construct a 3D digital surface representation, allowing for an estimation of the volume of space that a point cloud occupies. Given various point cloud imperfections, it is difficult for methods to generate digital surface representations of rockfall with detailed geometry and correct topology. In this study, we tested four different computational geometry-based surface reconstruction methods on a database comprised of 3668 rockfalls. The database was derived from a 5-year LiDAR monitoring campaign of an active rock slope in interior British Columbia, Canada. Each method resulted in a different magnitude-frequency distribution of rockfall. The implications of 3D volume estimation were demonstrated utilizing surface mesh visualization, cumulative magnitude-frequency plots, power-law fitting, and projected annual frequencies of rockfall occurrence. The 3D volume estimation methods caused a notable shift in the magnitude-frequency relations, while the power-law scaling parameters remained relatively similar. We determined that the optimal 3D volume calculation approach is a hybrid methodology comprised of the Power Crust reconstruction and the Alpha Solid reconstruction. The Alpha Solid approach is to be used on small-scale point clouds, characterized with high curvatures relative to their sampling density, which challenge the Power Crust sampling assumptions.

scholarly journals 3D-Volume Rendering of the Pelvis with Emphasis on Paraurethral Structures Based on MRI Scans and Comparisons between 3D Slicer and OsiriX®

2021 ◽  
Vol 45 (3) ◽  
Author(s):  
C. M. Durnea ◽  
S. Siddiqi ◽  
D. Nazarian ◽  
G. Munneke ◽  
P. M. Sedgwick ◽  
...  
Keyword(s):  
Image Processing ◽  
Secondary Analysis ◽  
Three Dimensional ◽  
3D Models ◽  
Clinical Role ◽  
Cross Sectional ◽  
3D Slicer ◽  
Mri Scans ◽  
3D Volume ◽  
Good Agreement

AbstractThe feasibility of rendering three dimensional (3D) pelvic models of vaginal, urethral and paraurethral lesions from 2D MRI has been demonstrated previously. To quantitatively compare 3D models using two different image processing applications: 3D Slicer and OsiriX. Secondary analysis and processing of five MRI scan based image sets from female patients aged 29–43 years old with vaginal or paraurethral lesions. Cross sectional image sets were used to create 3D models of the pelvic structures with 3D Slicer and OsiriX image processing applications. The linear dimensions of the models created using the two different methods were compared using Bland-Altman plots. The comparisons demonstrated good agreement between measurements from the two applications. The two data sets obtained from different image processing methods demonstrated good agreement. Both 3D Slicer and OsiriX can be used interchangeably and produce almost similar results. The clinical role of this investigation modality remains to be further evaluated.

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