scholarly journals The role of vertical mirror symmetry in visualshape detection

2009 ◽  
Vol 9 (12) ◽  
pp. 11-11 ◽  
Author(s):  
B. Machilsen ◽  
M. Pauwels ◽  
J. Wagemans
Keyword(s):  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haowei Xu ◽  
Hua Wang ◽  
Jian Zhou ◽  
Ju Li

AbstractSpin current generators are critical components for spintronics-based information processing. In this work, we theoretically and computationally investigate the bulk spin photovoltaic (BSPV) effect for creating DC spin current under light illumination. The only requirement for BSPV is inversion symmetry breaking, thus it applies to a broad range of materials and can be readily integrated with existing semiconductor technologies. The BSPV effect is a cousin of the bulk photovoltaic (BPV) effect, whereby a DC charge current is generated under light. Thanks to the different selection rules on spin and charge currents, a pure spin current can be realized if the system possesses mirror symmetry or inversion-mirror symmetry. The mechanism of BSPV and the role of the electronic relaxation time $$\tau$$ τ are also elucidated. We apply our theory to several distinct materials, including monolayer transition metal dichalcogenides, anti-ferromagnetic bilayer MnBi2Te4, and the surface of topological crystalline insulator cubic SnTe.


Cortex ◽  
2014 ◽  
Vol 51 ◽  
pp. 46-55 ◽  
Author(s):  
Silvia Bona ◽  
Andrew Herbert ◽  
Carlo Toneatto ◽  
Juha Silvanto ◽  
Zaira Cattaneo

i-Perception ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 204166951882034 ◽  
Author(s):  
Antonio Peta ◽  
Carlo Fantoni ◽  
Walter Gerbino

We report two experiments on the role of mid-level processes in image segmentation and completion. In the primed matching task of Experiment 1, a cue→prime sequence was presented before the imperative stimulus consisting of target shapes with positive versus negative contour curvature polarity and one versus two axes of mirror symmetry. Priming shapes were included in two composite occlusion displays with the same T-junction information and different geometric features supporting a distinct balance between completion and mosaic solutions. A cue, either congruent or incongruent with targets, preceded the presentation of the composite priming display. Matching performance was affected by primes in the expected direction, while cue congruency participated only in a marginally significant three-way interaction, and prime duration had no effect. In Experiment 2, the cue→prime sequence was replaced by a fixation cross to control for the priming effect obtained in Experiment 1. The study confirmed that contour connectability and curvature polarity are effective structural factors capable of competing with symmetry in mid-level image segmentation and completion processes.


2021 ◽  
Author(s):  
Beata Zagórska-Marek

Functioning in the Earth gravity field imposes on living organisms a necessity to read directions. The characteristic feature of their bodies, regardless unicellular or multicellular, is axial symmetry. The development of body plan orchestrated by spatiotemporal changes in gene expression patterns is based on formation of the vertical and radial axes. Especially for immobile plants, anchored to the substrate, vertical axis is primary and most important. But also in animals the primary is the axis, which defines the anterior and posterior pole of the embryo. There are many little known chiral processes and structures that are left- or right oriented with respect to this axis. Recent developments indicate the role of intrinsic cell chirality that determines the direction of developmental chiral processes in living organisms. The still enigmatic events in cambia of trees and handedness of phyllotaxis as well as plant living crystals are in focus of the chapter.


Symmetry ◽  
2014 ◽  
Vol 6 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Michaël Sassi ◽  
Maarten Demeyer ◽  
Johan Wagemans

1999 ◽  
Vol 08 (01) ◽  
pp. 11-16
Author(s):  
T. BAKER ◽  
B. LASIUK ◽  
C. RANGACHARYULU

The possible role of isobar degrees of freedom in nuclear structure accounting for departures from the symmetry properties of mirror nuclei is investigated. Specifically for [Formula: see text] conjugate pairs, we evaluate the corresponding mirror Gamow-Teller beta decays. In a simple model description, admixtures of isobar components at the few percent level can accommodate the experimentally observed asymmetries in mirror pairs of masses A=13 and 17.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Elena Gheorghiu ◽  
Frederick A. A. Kingdom ◽  
Aaron Remkes ◽  
Hyung-Chul O. Li ◽  
Stéphane Rainville

2015 ◽  
Vol 15 (12) ◽  
pp. 523
Author(s):  
Elena Gheorghiu ◽  
Frederick Kingdom ◽  
Aaron Remkes ◽  
Hyung-Chul Li ◽  
Stéphane Rainville

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