Vertical scale and vertical exaggeration in three‐dimensional contour maps of physical data

Geophysics ◽  
1983 ◽  
Vol 48 (6) ◽  
pp. 792-793
Author(s):  
S. Parker Gay

Gay (1971) described the application of three‐dimensional (3-D) viewing to geophysical data, principally contoured magnetic and gravity data. Subsequently, the method has been extensively applied to actual physical data, such as structural contour maps, isopach maps, and topography, both subaerial and submarine (e.g., Gay, 1981). These types of data have the same dimensions in the vertical and horizontal directions, i.e., physical distance. The question has therefore arisen many times over the years as to the mathematical relationship between the vertical and horizontal scales in the stereo model—what is the actual vertical exaggeration of a stereo view and how does one go about measuring it, or controlling it in case one is constructing a stereo pair? This question was not addressed in the 1971 paper, because there is no “true” vertical scale for gravity or magnetic maps, and hence no “exaggeration” (different dimensions in vertical and horizontal directions).

Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.


Author(s):  
W. Lin ◽  
J. Gregorio ◽  
T.J. Holmes ◽  
D. H. Szarowski ◽  
J.N. Turner

A low-light level video microscope with long working distance objective lenses has been built as part of our integrated three-dimensional (3-D) light microscopy workstation (Fig. 1). It allows the observation of living specimens under sufficiently low light illumination that no significant photobleaching or alternation of specimen physiology is produced. The improved image quality, depth discrimination and 3-D reconstruction provides a versatile intermediate resolution system that replaces the commonly used dissection microscope for initial image recording and positioning of microelectrodes for neurobiology. A 3-D image is displayed on-line to guide the execution of complex experiments. An image composed of 40 optical sections requires 7 minutes to process and display a stereo pair.The low-light level video microscope utilizes long working distance objective lenses from Mitutoyo (10X, 0.28NA, 37 mm working distance; 20X, 0.42NA, 20 mm working distance; 50X, 0.42NA, 20 mm working distance). They provide enough working distance to allow the placement of microelectrodes in the specimen.


2014 ◽  
Vol 941-944 ◽  
pp. 1678-1681
Author(s):  
Hong Bing Wang ◽  
Zhi Rong Li ◽  
Chun Hua Sun ◽  
Yi Ping Zhang

Filling unbalance is a critical defect for injection mould. When the upper and lower covers of soap plastic box are produced by injection mold at the same time, filling unbalance in injection would appear because of the different dimensions of the two parts. For advancing the quality of the soap plastic box, the runner system is optimized with the filling analysis module and flow runner balance module of moldflow simulation software. The three-dimensional geometrical models of the two covers are constructed using Pro/e software. In moldflow the runner balance optimization of the soap box compounding cavity is analysis. The results indicate the optimized cross section of the runners can reduce the flow unbalance ratio from 3.38% to 0.73%, and the filling time and pressure can satisfy the demands. According to the analysis results moldflow is appropriate for runner balance design of the plastic products.


2021 ◽  
Vol 16 (10) ◽  
pp. 50-58
Author(s):  
Ali Qusay Khalid ◽  
Vasudeva Rao Avupati ◽  
Husniza Hussain ◽  
Tabarek Najeeb Zaidan

Dengue fever is a viral infection spread by the female mosquito Aedes aegypti. It is a virus spread by mosquitoes found all over the tropics with risk levels varying depending on rainfall, relative humidity, temperature and urbanization. There are no specific medications that can be used to treat the condition. The development of possible bioactive ligands to combat Dengue fever before it becomes a pandemic is a global priority. Few studies on building three-dimensional quantitative structure-activity relationship (3D QSAR) models for anti-dengue agents have been reported. Thus, we aimed at building a statistically validated atom-based 3D-QSAR model using bioactive ligands reported to possess significant anti-dengue properties. In this study, the Schrodinger PhaseTM atom-based 3D QSAR model was developed and was validated using known anti-dengue properties as ligand data. This model was also tested to see if there was a link between structural characteristics and anti-dengue activity of a series of 3-acyl-indole derivatives. The established 3D QSAR model has strong predictive capacity and is statistically significant [Model: R2 Training Set = 0.93, Q2 (R2 Test Set) = 0.72]. In addition, the pharmacophore characteristics essential for the reported anti-dengue properties were explored using combined effects contour maps (coloured contour maps: blue: positive potential and red: negative potential) of the model. In the pathway of anti-dengue drug development, the model could be included as a virtual screening method to predict novel hits.


2021 ◽  
Vol 87 (5) ◽  
pp. 363-373
Author(s):  
Long Chen ◽  
Bo Wu ◽  
Yao Zhao ◽  
Yuan Li

Real-time acquisition and analysis of three-dimensional (3D) human body kinematics are essential in many applications. In this paper, we present a real-time photogrammetric system consisting of a stereo pair of red-green-blue (RGB) cameras. The system incorporates a multi-threaded and graphics processing unit (GPU)-accelerated solution for real-time extraction of 3D human kinematics. A deep learning approach is adopted to automatically extract two-dimensional (2D) human body features, which are then converted to 3D features based on photogrammetric processing, including dense image matching and triangulation. The multi-threading scheme and GPU-acceleration enable real-time acquisition and monitoring of 3D human body kinematics. Experimental analysis verified that the system processing rate reached ∼18 frames per second. The effective detection distance reached 15 m, with a geometric accuracy of better than 1% of the distance within a range of 12 m. The real-time measurement accuracy for human body kinematics ranged from 0.8% to 7.5%. The results suggest that the proposed system is capable of real-time acquisition and monitoring of 3D human kinematics with favorable performance, showing great potential for various applications.


Perception ◽  
10.1068/p3440 ◽  
2002 ◽  
Vol 31 (11) ◽  
pp. 1323-1333 ◽  
Author(s):  
Ellen M Berends ◽  
Raymond van Ee ◽  
Casper J Erkelens

It has been well established that vertical disparity is involved in perception of the three-dimensional layout of a visual scene. The goal of this paper was to examine whether vertical disparities can alter perceived direction. We dissociated the common relationship between vertical disparity and the stimulus direction by applying a vertical magnification to the image presented to one eye. We used a staircase paradigm to measure whether perceived straight-ahead depended on the amount of vertical magnification in the stimulus. Subjects judged whether a test dot was flashed to either the left or the right side of straight-ahead. We found that perceived straight-ahead did indeed depend on the amount of vertical magnification but only after subjects adapted (for 5 min) to vertical scale (and only in five out of nine subjects). We argue that vertical disparity is a factor in the calibration of the relationship between eye-position signals and perceived direction.


The electron density distribution in the unit cell is calculated at intervals of approximately 2Å and plotted in a series of sections parallel to (010). The contour maps show that haemoglobin consists of four subunits in a tetrahedral array. The subunits are identical in pairs in accordance with the twofold symmetry of the molecule. The two pairs are very similar in structure, and the members of each pair closely resemble the molecule of sperm-whale myoglobin. The four haem groups lie in separate pockets at the surface of the molecule. The positions of the iron atoms are confirmed by comparison of observed and calculated anomalous scattering effects, which also serve to determine the absolute configuration of the molecule. The four subunits found by X-ray analysis correspond to the four polypeptide chains into which haemoglobin can be divided by chemical methods. In horse haemoglobin the amino acid sequence within these chains is still partly unknown, but in human haemoglobin it has already been determined. Comparison of this sequence with the tertiary structure of the chains as now revealed in horse haemoglobin and with the atomic model of sperm-whale myoglobin recently obtained by Kendrew and his collaborators shows many interesting relations. Prolines appear to come where the chains turn corners or where their configuration is known to be non-helical. On the other hand, the chains also have corners which contain no proline. Certain residues appear to be structurally vital, because they appear in identical positions in myoglobin and in the two chains of haemoglobin, while in other parts of the molecule a wide variety of different side-chains appears to be allowed.


2021 ◽  
Author(s):  
◽  
Alistair Stronach

<p><b>New Zealand’s capital city of Wellington lies in an area of high seismic risk, which is further increased by the sedimentary basin beneath the Central Business District (CBD). Ground motion data and damage patterns from the 2013 Cook Strait and 2016 Kaikōura earthquakes indicate that two- and three-dimensional amplification effects due to the Wellington sedimentary basin may be significant. These effects are not currently accounted for in the New Zealand Building Code. In order for this to be done, three-dimensional simulations of earthquake shaking need to be undertaken, which requires detailed knowledge of basin geometry. This is currently lacking, primarily because of a dearth of deep boreholes in the CBD area, particularly in Thorndon and Pipitea where sediment depths are estimated to be greatest.</b></p> <p>A new basin depth map for the Wellington CBD has been created by conducting a gravity survey using a modern Scintrex CG-6 gravity meter. Across the study area, 519 new high precision gravity measurements were made and a residual anomaly map created, showing a maximum amplitude anomaly of -6.2 mGal with uncertainties better than ±0.1 mGal. Thirteen two-dimensional geological profiles were modelled to fit the anomalies, then combined with existing borehole constraints to construct the basin depth map. </p> <p>Results indicate on average greater depths than in existing models, particularly in Pipitea where depths are interpreted to be as great as 450 m, a difference of 250 m. Within 1 km of shore depths are interpreted to increase further, to 600 m. The recently discovered basin bounding Aotea Fault is resolved in the gravity data, where the basement is offset by up to 13 m, gravity anomaly gradients up to 8 mGal/km are observed, and possible multiple fault strands identified. A secondary strand of the Wellington Fault is also identified in the north of Pipitea, where gravity anomaly gradients up to 18 mGal/km are observed.</p>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jana Andrejewski ◽  
Fabio De Marco ◽  
Konstantin Willer ◽  
Wolfgang Noichl ◽  
Theresa Urban ◽  
...  

AbstractX-ray dark-field imaging is a widely researched imaging technique, with many studies on samples of very different dimensions and at very different resolutions. However, retrieval of three-dimensional (3D) information for human thorax sized objects has not yet been demonstrated. We present a method, similar to classic tomography and tomosynthesis, to obtain 3D information in X-ray dark-field imaging. Here, the sample is moved through the divergent beam of a Talbot–Lau interferometer. Projections of features at different distances from the source seemingly move with different velocities over the detector, due to the cone beam geometry. The reconstruction of different focal planes exploits this effect. We imaged a chest phantom and were able to locate different features in the sample (e.g. the ribs, and two sample vials filled with water and air and placed in the phantom) to corresponding focal planes. Furthermore, we found that image quality and detectability of features is sufficient for image reconstruction with a dose of 68 μSv at an effective pixel size of $$0.357 \times {0.357}\,\mathrm{mm}^{2}$$ 0.357 × 0.357 mm 2 . Therefore, we successfully demonstrated that the presented method is able to retrieve 3D information in X-ray dark-field imaging.


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