scholarly journals Experimental results and simulations from aperture synthesis three-dimensional radiometric imaging

2016 ◽  
Author(s):  
Neil A. Salmon
Keyword(s):  
Three Dimensional ◽  
Aperture Synthesis ◽  
Experimental Results

Conical SNA using fuzzy k-medoids based on user experience

2021 ◽  
pp. 002072092098849
Author(s):  
Poonam Rani ◽  
MPS Bhatia ◽  
Devendra K Tayal
Keyword(s):  
Social Networks ◽  
Social Network ◽  
User Experience ◽  
Three Dimensional ◽  
Experimental Results ◽  
Dynamic Parameters ◽  
Clustering Method ◽  
Cone Model ◽  
Intelligent Approach ◽  
Conical Model

The paper presents an intelligent approach for the comparison of social networks through a cone model by using the fuzzy k-medoids clustering method. It makes use of a geometrical three-dimensional conical model, which astutely represents the user experience views. It uses both the static as well as the dynamic parameters of social networks. In this, we propose an algorithm that investigates which social network is more fruitful. For the experimental results, the proposed work is employed on the data collected from students from different universities through the Google forms, where students are required to rate their experience of using different social networks on different scales.

Research on Transition Zones of Spherical Surface Parts in 3D Rolling Process

2014 ◽  
Vol 687-691 ◽  
pp. 3-6
Author(s):  
Da Ming Wang ◽  
Ming Zhe Li ◽  
Zhong Yi Cai
Keyword(s):  
Sheet Metal ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Rolling Process ◽  
Experimental Results ◽  
Transition Zones ◽  
Spherical Surfaces ◽  
Sheet Width ◽  
Forming Precision ◽  
Roll Gap

3D rolling is a novel technology for three-dimensional surface parts. In this process, by controlling the gap between the upper and lower forming rolls, the sheet metal is non-uniformly thinned in thickness direction, and the longitudinal elongation of the sheet metal is different along the transverse direction, which makes the sheet metal generate three-dimensional deformation. In this paper, the transition zones of spherical surface parts in 3D rolling process are investigated. Spherical surface parts with the same widths but different lengths are simulated in condition of the same roll gap, and their experimental results are presented. The forming precision of forming parts and the causes of transition zones in the head and tail regions are analyzed through simulated results. The simulated and experimental results show that the lengths of transition zones of spherical surfaces in the head and tail regions are fixed values in condition of the same sheet width and roll gap.

Segmentation of Kidneys from Computed Tomography Using 3D Fast GrowCut Algorithm

2013 ◽  
Vol 333-335 ◽  
pp. 1145-1150 ◽  
Author(s):  
Gao Yuan Dai ◽  
Zhi Cheng Li ◽  
Jia Gu ◽  
Lei Wang ◽  
Xing Min Li ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Experimental Results ◽  
Volume Data ◽  
Great Role ◽  
Color Features ◽  
Monotonically Decreasing Function ◽  
Kidney Segmentation ◽  
Ct Volume

This paper proposes a fast GrowCut (FGC) algorithm and applies the new algorithm in three-dimensional (3D)kidney segmentation from computed tomography (CT) volume data. Users could mark the object of interest with different labels in CT slices.FGC propagates the labels using monotonically decreasing function and color features to derive an optimal cut for a given data in space. The color features play a great role in comparing with neighborhood cells. The experimental results clearly demonstrate the superiority of FGC in accuracy and speed.

Finite Element Study of the Cutting Mechanics of the Three Dimensional Rock Turning Process

2015 ◽  
Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Polycrystalline Diamond ◽  
Close Correlation ◽  
Experimental Results ◽  
Failure Behavior ◽  
Fe Model ◽  
Gas Drilling ◽  
Cutting Mechanics

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.

scholarly journals Contribution of upper airway geometry to convective mixing

2008 ◽  
Vol 105 (6) ◽  
pp. 1733-1740 ◽  
Author(s):  
Santhosh T. Jayaraju ◽  
Manuel Paiva ◽  
Mark Brouns ◽  
Chris Lacor ◽  
Sylvia Verbanck
Keyword(s):  
Three Dimensional ◽  
Upper Airway ◽  
Axial Dispersion ◽  
Half Width ◽  
Experimental Results ◽  
Cfd Simulations ◽  
Flow Rates ◽  
Axial Dispersion Coefficient ◽  
Dispersive Effect ◽  
Flow Directions

We investigated the axial dispersive effect of the upper airway structure (comprising mouth cavity, oropharynx, and trachea) on a traversing aerosol bolus. This was done by means of aerosol bolus experiments on a hollow cast of a realistic upper airway model (UAM) and three-dimensional computational fluid dynamics (CFD) simulations in the same UAM geometry. The experiments showed that 50-ml boluses injected into the UAM dispersed to boluses with a half-width ranging from 80 to 90 ml at the UAM exit, across both flow rates (250, 500 ml/s) and both flow directions (inspiration, expiration). These experimental results imply that the net half-width induced by the UAM typically was 69 ml. Comparison of experimental bolus traces with a one-dimensional Gaussian-derived analytical solution resulted in an axial dispersion coefficient of 200–250 cm2/s, depending on whether the bolus peak and its half-width or the bolus tail needed to be fully accounted for. CFD simulations agreed well with experimental results for inspiratory boluses and were compatible with an axial dispersion of 200 cm2/s. However, for expiratory boluses the CFD simulations showed a very tight bolus peak followed by an elongated tail, in sharp contrast to the expiratory bolus experiments. This indicates that CFD methods that are widely used to predict the fate of aerosols in the human upper airway, where flow is transitional, need to be critically assessed, possibly via aerosol bolus simulations. We conclude that, with all its geometric complexity, the upper airway introduces a relatively mild dispersion on a traversing aerosol bolus for normal breathing flow rates in inspiratory and expiratory flow directions.

scholarly journals Magnetic Field Structure of Star Forming Regions: VLBI Spectral Line Results

1984 ◽  
Vol 110 ◽  
pp. 333-334
Author(s):  
J.A. Garcia-Barreto ◽  
B. F. Burke ◽  
M. J. Reid ◽  
J. M. Moran ◽  
A. D. Haschick
Keyword(s):  
Magnetic Field ◽  
Three Dimensional ◽  
Aperture Synthesis ◽  
Stokes Parameters ◽  
Hii Region ◽  
Star Forming ◽  
Star Forming Regions ◽  
Vlbi Observations ◽  
The Magnetic Field ◽  
Synthesis Experiment

Magnetic fields play a major role in the general dynamics of astronomical phenomena and particularly in the process of star formation. The magnetic field strength in galactic molecular clouds is of the order of few tens of μG. On a smaller scale, OH masers exhibit fields of the order of mG and these can probably be taken as representative of the magnetic field in the dense regions surrounding protostars. The OH molecule has been shown to emit highly circular and linearly polarized radiation. That it was indeed the action of the magnetic field that would give rise to the highly polarized spectrum of OH has been shown by the VLBI observations of Zeeman pairs of the 1720 and 6035 MHz by Lo et. al. and Moran et. al. VLBI observations of W3 (OH) revealed that the OH emission was coming from numerous discrete locations and that all spots fell within the continuum contours of the compact HII region. The most detailed VLBI aperture synthesis experiment of the 1665 MHz emission from W3 (OH) was carried out by Reid et. al. who found several Zeeman pairs and a characteristic maser clump size of 30 mas. In this work, we report the results of a 5 station VLBI aperture synthesis experiment of the 1665 MHz OH emission from W3 (OH) with full polarization information. We produced VLBI synthesis maps of all Stokes parameters of 16 spectral features that showed elliptical polarization. The magnitude and direction of the magnetic field have been obtained by the detection of 7 Zeeman pairs. The three dimensional orientation of the magnetic field can be obtained, following the theoretical arguments of Goldreich et. al., from the observation of π and σ components.

scholarly journals TSUNAMI GENERATION AND PROPAGATION

1972 ◽  
Vol 1 (13) ◽  
pp. 146
Author(s):  
Joseph L. Hammack ◽  
Frederic Raichlen
Keyword(s):  
Linear Theory ◽  
Source Region ◽  
Three Dimensional ◽  
Frequency Dispersion ◽  
Nonlinear Effects ◽  
Its Region ◽  
Experimental Results ◽  
Specific Class ◽  
Two Dimensional ◽  
Three Dimensional Models

A linear theory is presented for waves generated by an arbitrary bed deformation {in space and time) for a two-dimensional and a three -dimensional fluid domain of uniform depth. The resulting wave profile near the source is computed for both the two and three-dimensional models for a specific class of bed deformations; experimental results are presented for the two-dimensional model. The growth of nonlinear effects during wave propagation in an ocean of uniform depth and the corresponding limitations of the linear theory are investigated. A strategy is presented for determining wave behavior at large distances from the source where linear and nonlinear effects are of equal magnitude. The strategy is based on a matching technique which employs the linear theory in its region of applicability and an equation similar to that of Korteweg and deVries (KdV) in the region where nonlinearities are equal in magnitude to frequency dispersion. Comparison of the theoretical computations with the experimental results indicates that an equation of the KdV type is the proper model of wave behavior at large distances from the source region.

scholarly journals MEMS-Based Integrated Triaxial Electrochemical Seismometer

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1156
Author(s):  
Wenjie Qi ◽  
Bowen Liu ◽  
Tian Liang ◽  
Jian Chen ◽  
Deyong Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Ground Motion ◽  
Small Volume ◽  
Three Dimensional ◽  
Experimental Results ◽  
Good Prospect ◽  
High Symmetry ◽  
Noise Levels ◽  
Sensitivity Curves ◽  
Simulation Results

This paper presents a micro-electromechanical systems (MEMS)-based integrated triaxial electrochemical seismometer, which can detect three-dimensional vibration. By integrating three axes, the integrated triaxial electrochemical seismometer is characterized by small volume and high symmetry. The numerical simulation results inferred that the integrated triaxial electrochemical seismometer had excellent independence among three axes. Based on the experimental results, the integrated triaxial electrochemical seismometer had the advantage of small axial crosstalk and could detect vibration in arbitrary directions. Furthermore, compared with the uniaxial electrochemical seismometer, the integrated triaxial electrochemical seismometer had similar sensitivity curves ranging from 0.01 to 100 Hz. In terms of random ground motion response, high consistencies between the developed integrated triaxial electrochemical seismometer and the uniaxial electrochemical seismometer could be easily observed, which indicated that the developed integrated triaxial electrochemical seismometer produced comparable noise levels to those of the uniaxial electrochemical seismometer. These results validated the performance of the integrated triaxial electrochemical seismometer, which has a good prospect in the field of deep geophysical exploration and submarine seismic monitoring.

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