Description of Curved 3-D Objects from Single Intensity Images

2000 ◽  
Author(s):  
Bruce Flinchbaugh
Keyword(s):  
Intensity Images

Selective Area Epitaxy of InGaN/GaN Stripes, Hexagonal Rings, and Triangular Rings for Achieving Green Emission

2009 ◽  
Vol 1202 ◽  
Author(s):  
Wen Feng ◽  
Vladimir Kuryatkov ◽  
Dana Rosenbladt ◽  
Nenad Stojanovic ◽  
Mahesh Pandikunta ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Green Emission ◽  
Single Type ◽  
Selective Area Epitaxy ◽  
Polar Crystal ◽  
Selective Area ◽  
Narrow Ridge ◽  
Intensity Images ◽  
Two Peaks ◽  
Surface Morphologies

AbstractWe report selective area epitaxy of InGaN/GaN micron-scale stripes and rings on patterned (0001) AlN/sapphire. The objective is to elevate indium incorporation for achieving blue and green emission on semi-polar crystal facets. In each case, GaN structures were first produced, and the InGaN quantum wells (QWs) were subsequently grown. The pyramidal InGaN/GaN stripe along the <11-20> direction has uniform CL emission at 500 nm on the smooth {1-101} sidewall and at 550 nm on the narrow ridge. In InGaN/GaN triangular rings, the structures reveal smooth inner and outer sidewall facets falling into a single type of {1-101} planes. All these {1-101} sidewall facets demonstrate similar CL spectra which appear to be the superposition of two peaks at positions 500 nm and 460 nm. Spatially matched striations are observed in the CL intensity images and surface morphologies of the {1-101} sidewall facets. InGaN/GaN hexagonal rings are comprised of {11-22} and {21-33} facets on inner sidewalls, and {1-101} facets on outer sidewalls. Distinct CL spectra with peak wavelengths as long as 500 nm are observed for these diverse sidewall facets of the hexagonal rings.

scholarly journals Persistent magnetic vortex flow at a supergranular vertex

2018 ◽  
Vol 610 ◽  
pp. A84 ◽  
Author(s):  
Iker S. Requerey ◽  
Basilio Ruiz Cobo ◽  
Milan Gošić ◽  
Luis R. Bellot Rubio
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Vortex Flow ◽  
Spatial Scales ◽  
Magnetic Vortex ◽  
Magnetic Feature ◽  
Magnetic Element ◽  
Flow Maps ◽  
Wide Range ◽  
Intensity Images

Context. Photospheric vortex flows are thought to play a key role in the evolution of magnetic fields. Recent studies show that these swirling motions are ubiquitous in the solar surface convection and occur in a wide range of temporal and spatial scales. Their interplay with magnetic fields is poorly characterized, however. Aims. We study the relation between a persistent photospheric vortex flow and the evolution of a network magnetic element at a supergranular vertex. Methods. We used long-duration sequences of continuum intensity images acquired with Hinode and the local correlation-tracking method to derive the horizontal photospheric flows. Supergranular cells are detected as large-scale divergence structures in the flow maps. At their vertices, and cospatial with network magnetic elements, the velocity flows converge on a central point. Results. One of these converging flows is observed as a vortex during the whole 24 h time series. It consists of three consecutive vortices that appear nearly at the same location. At their core, a network magnetic element is also detected. Its evolution is strongly correlated to that of the vortices. The magnetic feature is concentrated and evacuated when it is caught by the vortices and is weakened and fragmented after the whirls disappear. Conclusions. This evolutionary behavior supports the picture presented previously, where a small flux tube becomes stable when it is surrounded by a vortex flow.

scholarly journals Emotion Regulation Choice: Differences in U.S. and Indian Populations

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Ashish Mehta ◽  
Gerald Young ◽  
Alyssa Wicker ◽  
Sarah Barber ◽  
Gaurav Suri
Keyword(s):  
Emotion Regulation ◽  
Choice Behavior ◽  
Indian Philosophy ◽  
Empirical Studies ◽  
Cognitive Reappraisal ◽  
The Past ◽  
Intensity Images ◽  
Internal And External Factors ◽  
Effective Use

In the past two decades, researchers have conclusively demonstrated that various emotion regulation (ER) strategies give rise to differing consequences. Such findings have prompted an examination of the internal and external factors that contribute to emotion regulation choice. Previous empirical studies modeling ER choice have been limited to Western samples. Based on knowledge of the role of culture in other choice behavior, we sought to test whether culture was a driver of ER choice. For the present studies, we compared ER choices of participants from India, to ER choices of participants from the U.S.A. Research demonstrating a correlation between religiosity and effective use of cognitive reappraisal lead us to anticipate the more religious India showing higher rates of cognitive reappraisal. Based on the incorporation of acceptance themes in Indian philosophy, as well as higher rates of fatalistic outlooks in India, we also expected to see Indian participants more frequently using an acceptance ER strategy. We further expected that difference in choice strategies would be moderated by emotional intensity of the stimuli. To test these hypotheses, we presented high and low-intensity emotion-eliciting images to both samples and recorded ER choice selections. We discovered that as hypothesized, the Indian sample was significantly more likely to use cognitive reappraisal than the U.S. sample, specifically for high intensity images. Contrary to our hypothesis, the choice rate for acceptance was indistinguishable in the Indian and U.S. samples. This research indicates that culture bears considerably on which strategies people choose to employ when regulating emotion in response to negative stimuli.

scholarly journals Estimation of three-dimensional crustal movements in the 2011 Tohoku-oki, Japan earthquake from TerraSAR-X intensity images

2014 ◽  
Vol 2 (12) ◽  
pp. 7383-7408
Author(s):  
W. Liu ◽  
F. Yamazaki ◽  
M. Matsuoka ◽  
T. Nonaka ◽  
T. Sasagawa
Keyword(s):  
Three Dimensional ◽  
Short Time Period ◽  
Sar Images ◽  
Crustal Movements ◽  
Surface Displacements ◽  
Time Period ◽  
Intensity Images ◽  
Short Time ◽  
The Relationship ◽  
Gps Observations

Abstract. The Tohoku-Oki earthquake on 11 March 2011 caused significant widespread crustal movements. In a previous study, we proposed a method for capturing two-dimensional (2-D) surface displacements from a pair of pre- and post-event TerraSAR-X (TSX) intensity images. However, it is difficult to detect three-dimensional (3-D) displacements from one pair of TSX images. In this study, three pairs of pre- and post-event TSX images taken on different paths were used to estimate 3-D crustal movements. The relationship between the actual 3-D displacements and the converted 2-D movements in the SAR images was derived based on the observation model of a SAR sensor. The 3-D movements were then calculated from three sets of detected 2-D movements that occurred within a short time period. Compared with GPS observations, the proposed method was found to be capable of detecting the 3-D crustal movements with sub-pixel accuracy.

scholarly journals Real-Time Detection of Non-Stationary Objects Using Intensity Data in Automotive LiDAR SLAM

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6781
Author(s):  
Tomasz Nowak ◽  
Krzysztof Ćwian ◽  
Piotr Skrzypczyński
Keyword(s):  
Real Time ◽  
Network Models ◽  
Point Clouds ◽  
Intensity Data ◽  
Neural Network Models ◽  
Localization And Mapping ◽  
Stationary Objects ◽  
Intensity Images ◽  
Real Time Detection ◽  
Segmentation Task

This article aims at demonstrating the feasibility of modern deep learning techniques for the real-time detection of non-stationary objects in point clouds obtained from 3-D light detecting and ranging (LiDAR) sensors. The motion segmentation task is considered in the application context of automotive Simultaneous Localization and Mapping (SLAM), where we often need to distinguish between the static parts of the environment with respect to which we localize the vehicle, and non-stationary objects that should not be included in the map for localization. Non-stationary objects do not provide repeatable readouts, because they can be in motion, like vehicles and pedestrians, or because they do not have a rigid, stable surface, like trees and lawns. The proposed approach exploits images synthesized from the received intensity data yielded by the modern LiDARs along with the usual range measurements. We demonstrate that non-stationary objects can be detected using neural network models trained with 2-D grayscale images in the supervised or unsupervised training process. This concept makes it possible to alleviate the lack of large datasets of 3-D laser scans with point-wise annotations for non-stationary objects. The point clouds are filtered using the corresponding intensity images with labeled pixels. Finally, we demonstrate that the detection of non-stationary objects using our approach improves the localization results and map consistency in a laser-based SLAM system.

scholarly journals Relative depolarization of the black hole photon ring in GRMHD models of Sgr A* and M87*

2021 ◽  
Vol 503 (3) ◽  
pp. 4563-4575
Author(s):  
A Jiménez-Rosales ◽  
J Dexter ◽  
S M Ressler ◽  
A Tchekhovskoy ◽  
M Bauböck ◽  
...  
Keyword(s):  
Black Hole ◽  
Relativistic Effects ◽  
Image Features ◽  
Black Hole Mass ◽  
Magnetic Turbulence ◽  
Intensity Images ◽  
General Relativistic ◽  
Sharp Image ◽  
Sgr A ◽  
Magnetohydrodynamic Simulations

ABSTRACT Using general relativistic magnetohydrodynamic simulations of accreting black holes, we show that a suitable subtraction of the linear polarization per pixel from total intensity images can enhance the photon ring feature. We find that the photon ring is typically a factor of ≃2 less polarized than the rest of the image. This is due to a combination of plasma and general relativistic effects, as well as magnetic turbulence. When there are no other persistently depolarized image features, adding the subtracted residuals over time results in a sharp image of the photon ring. We show that the method works well for sample, viable GRMHD models of Sgr A* and M87*, where measurements of the photon ring properties would provide new measurements of black hole mass and spin, and potentially allow for tests of the ‘no-hair’ theorem of general relativity.

Distinction between some saccharides in scattered optical sum frequency intensity images

2005 ◽  
Vol 62 (4-5) ◽  
pp. 845-849 ◽  
Author(s):  
G. Mizutani ◽  
T. Koyama ◽  
S. Tomizawa ◽  
H. Sano
Keyword(s):  
Sum Frequency ◽  
Intensity Images ◽  
Frequency Intensity
Sign in / Sign up

Export Citation Format

Share Document