Two-dimensional pattern recognition methods for rapidly recording and interpreting high resolution coherent three-dimensional spectra

2021 ◽  
Vol 154 (19) ◽  
pp. 194201
Author(s):  
Thresa A. Wells ◽  
Muhire H. Kwizera ◽  
Sarah M. Chen ◽  
Nihal Jemal ◽  
Morgan D. Brown ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
High Resolution ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Pattern Recognition Methods

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Photogrammetric Investigation of the Flying Shape of Spinnakers in a Twisted Flow Wind Tunnel

2009 ◽  
Author(s):  
Kai Graf ◽  
Olaf Müller
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
High Resolution ◽  
Wind Tunnel ◽  
Wind Velocity ◽  
Digital Cameras ◽  
Pattern Recognition Methods ◽  
Twisted Flow ◽  
High Resolution Images ◽  
The Impact

This paper describes a method for the acquisition of the flying shape of spinnakers in a twisted flow wind tunnel. The method is based on photogrammetry. A set of digital cameras is used to obtain high resolution images of the spinnaker from different viewing angles. The images are post-processed using image-processing tools, pattern recognition methods and finally the photogrammetry algorithm. Results are shown comparing design versus flying shape of the spinnaker and the impact of wind velocity and wind twist on the flying shape. Finally some common rules for optimum spinnaker trimming are investigated and examined.

scholarly journals On inertial-range scaling laws

1996 ◽  
Vol 306 ◽  
pp. 167-181 ◽  
Author(s):  
John C. Bowman
Keyword(s):  
Steady State ◽  
High Resolution ◽  
Scaling Laws ◽  
State Energy ◽  
Three Dimensional ◽  
Inertial Range ◽  
Energy Spectra ◽  
Two Dimensional ◽  
Unified Framework ◽  
Asymptotic Nature

Inertial-range scaling laws for two- and three-dimensional turbulence are re-examined within a unified framework. A new correction to Kolmogorov's k−5/3 scaling is derived for the energy inertial range. A related modification is found to Kraichnan's logarithmically corrected two-dimensional enstrophy-range law that removes its unexpected divergence at the injection wavenumber. The significance of these corrections is illustrated with steady-state energy spectra from recent high-resolution closure computations. Implications for conventional numerical simulations are discussed. These results underscore the asymptotic nature of inertial-range scaling laws.

FRACTAL DIMENSIONALITY OF PORE AND GRAIN VOLUME OF A SILICICLASTIC MARINE SAND

2000 ◽  
Vol 11 (08) ◽  
pp. 1555-1559 ◽  
Author(s):  
A. H. REED ◽  
R. B. PANDEY ◽  
D. L. LAVOIE
Keyword(s):  
Weight Loss ◽  
High Resolution ◽  
Pore Volume ◽  
Three Dimensional ◽  
Fractal Dimensionality ◽  
Ct Images ◽  
Spatial Distributions ◽  
Two Dimensional ◽  
Linear Gradient ◽  
Marine Sand

Three-dimensional (3D) spatial distributions of pore and grain volumes were determined from high-resolution computer tomography (CT) images of resin-impregnated marine sands. Using a linear gradient extrapolation method, cubic three-dimensional samples were constructed from two-dimensional CT images. Image porosity (0.37) was found to be consistent with the estimate of porosity by water weight loss technique (0.36). Scaling of the pore volume (Vp) with the linear size (L), V ~ LD provides the fractal dimensionalities of the pore volume (D = 2.74 ± 0.02) and grain volume (D = 2.90 ± 0.02) typical for sedimentary materials.

High Resolution Synchrotron X-Ray Diffraction Tomography Of Large-Grained Samples

1996 ◽  
Vol 437 ◽  
Author(s):  
D.P. Piotrowski ◽  
S.R. Stock ◽  
A. Guvenilir ◽  
J.D. Haase ◽  
Z.U. Rek
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Diffraction Tomography ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Image Storage ◽  
X Ray ◽  
Dimensional Distribution

AbstractIn order to understand the macroscopic response of polycrystalline structural materials to loading, it is frequently essential to know the spatial distribution of strain as well as the variation of micro-texture on the scale of 100 μm. The methods must be nondestructive, however, if the three-dimensional evolution of strain is to be studied. This paper describes an approach to high resolution synchrotron x-ray diffraction tomography of polycrystalline materials. Results from model samples of randomly-packed, millimeter-sized pieces of Si wafers and of similarly sized single-crystal Al blocks have been obtained which indicate that polychromatic beams collimated to 30 μm diameter can be used to determine the depth of diffracting volume elements within ± 70 μm. The variation in the two-dimensional distribution of diffracted intensity with changing sample to detector separation is recorded on image storage plates and used to infer the depth of diffracting volume elements.

Electron Crystallographic Determination of the Structure of Bacteriorhodopsin

1990 ◽  
Vol 48 (1) ◽  
pp. 90-91
Author(s):  
R. Henderson ◽  
J.M. Baldwin ◽  
T.A. Ceska ◽  
E. Beckman ◽  
F. Zemlin ◽  
...  
Keyword(s):  
High Resolution ◽  
Proton Pump ◽  
Three Dimensional ◽  
Atomic Resolution ◽  
Two Dimensional ◽  
New Methods ◽  
Density Map ◽  
Diffraction Patterns

The light driven proton pump bacteriorhodopsin (bR) occurs naturally as two-dimensional crystals. A three-dimensional density map of the structure, at near atomic resolution, has been obtained by studying the crystals using electron cryo-microscopy to obtain diffraction patterns and high resolution micrographs (1).New methods have been developed for analysing micrographs from tilted specimens, incorporating the methods previously developed for untilted specimens that enable large areas to be analysed and corrected for distortions. Data from 72 images, from both tilted and untilted specimens, have been analysed to produce the phases of 2700 independent Fourier components of the structure. The amplitudes of these components have been accurately measured from 150 diffraction patterns. Together, these data represent about half of the full three-dimensional transform to 3.5 Å. The distribution of the data which is included in the map is shown in fig. 1. For specimen tilts up to around 20° the data is essentially complete. For higher tilts the data is more sparsely sampled, and is at present about half complete.

Synthetic aperture diffraction tomography for three-dimensional imaging

2009 ◽  
Vol 465 (2109) ◽  
pp. 2877-2895 ◽  
Author(s):  
Francesco Simonetti ◽  
Lianjie Huang
Keyword(s):  
World War Ii ◽  
High Resolution ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Sensor Technology ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Theoretical Formulation ◽  
Three Dimensional Objects ◽  
Aperture Diffraction

Tomography of complex three-dimensional objects with ultrasound or microwave has been a long-standing goal since the introduction of these technologies after World War II. While current state-of-the-art systems can provide high-resolution images of cylindrical objects characterized by a two-dimensional structure, the three-dimensional case remains an open challenge owing to current limitations of sensor technology and computer power. Here, this problem is addressed by means of a synthetic aperture technique that, while using hardware technology developed for two-dimensional problems, accounts for the complexity of three-dimensional scattering and leads to high-resolution three-dimensional reconstructions. In this paper, we present the theoretical formulation of this new approach and illustrate it by means of a numerical example.

Treatment of the gradient of defocus in images of tilted, thin crystals

1986 ◽  
Vol 44 ◽  
pp. 6-9
Author(s):  
R. Henderson ◽  
J.M. Baldwin
Keyword(s):  
Image Analysis ◽  
High Resolution ◽  
Electron Diffraction ◽  
Low Temperature ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Two Dimensional ◽  
Computer Image Analysis ◽  
Crystal Forms ◽  
Cell Dimensions

Bacteriorhodopsin, a membrane protein from Halobacteria, forms two-dimensional crystals which often have diameters of 20 microns. Several crystal forms have been obtained with cell dimensions of about 60 Å and diffraction to beyond 3 Å resolution. The structure of one of these crystal forms has recently been determined in projection at 3.5 Å resolution using images recorded at low temperature, together with computer image analysis methods that enable the averaging of information from areas of up to 1 micron in diameter. Electron diffraction intensities have also been recorded from tilted and untilted specimens providing three-dimensional amplitude measurements to 3 Å resolution. We are now analysing images from tilted specimens that should provide phases for the Fourier components of the structure to high resolution in three dimensions.

Sign in / Sign up

Export Citation Format

Share Document