Results 11 to 20 of about 5,706,267 (307)
On Point-Symmetric Tournaments
Canadian Mathematical Bulletin, 1970 A tournament is a directed graph in which there is exactly one arc between any two distinct vertices. Let denote the automorphism group of T. A tournament T is said to be point-symmetric if acts transitively on the vertices of T. Let g(n) be the maximum value of taken over all tournaments of order n.
B. Alspach
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Nature Communications, 2018 The study of parity-time (PT) symmetric optical systems has recently attracted much attention. Here, the authors experimentally study an anti-PT symmetric circuit system and observe an exceptional point with an inverse PT symmetry breaking transition and
Youngsun Choi +3 more
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Optics Express, 2015 We design and demonstrate a wideband silicon photonic polarization beamsplitter on a silicon-on-insulator platform. The device consists of two 3 dB broadband couplers cascaded in a point-symmetric network. The transverse electric (TE) and transverse magnetic (TM) modes are coupled to different output ports due to a large difference between their ...
Zeqin, Lu +4 more
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Wobbling Accretion Disks, Jets, and Point‐symmetric Nebulae [PDF]
The Astrophysical Journal, 1997 We present numerical calculations of the evolution of an accretion disk that is irradiated by a central source. The parameters chosen represent those of the central star of a planetary nebula. We show that an irradiation-induced warping can occur in the disk and that it is accompanied by a wobbling motion in both the inclination and azimuthal ...
Mario Livio, J. E. Pringle
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The Formation of Point-symmetric Nebulae
The Astrophysical Journal, 1996 A number of the extended planetary nebulae show point-symmetric morphology, and it has been suggested that such a morphology is the consequence of the episodic ejection of material in a two-sided jet. Here we show that the accretion disk, previously postulated to be formed in the final stages of common envelope evolution giving rise to the planetary ...
Mario Livio, J. E. Pringle
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The Kinematics of Point-symmetric Planetary Nebulae
The Astronomical Journal, 1999 Four planetary nebulae (PNe) with conspicuous point-symmetric morphology are studied in this paper through high-quality imagery and long-slit echelle spectroscopy. Point symmetry is also found in the velocity space, and this is related to particular forms of bipolar collimated outflows.
M. A. Guerrero +2 more
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Three-Dimensional Adaptive Mesh Refinement Simulations of Point-Symmetric Nebulae
, 2003 4 pages, 2 figures, to appear in "Asymmetrical Planetary Nebulae III" editors M. Meixner, J. Kastner, N. Soker, & B. Balick (ASP Conf. Series).
Rijkhorst, E.-J., Icke, V., Mellema, G.
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Simulating the Shaping of Point-symmetric Structures in the Jittering Jets Explosion Mechanism
Publications of the Astronomical Society of the PacificAbstract We conduct three-dimensional hydrodynamical simulations of core-collapse supernovae by launching several pairs of jets into a collapsing core model and show that the jittering jets explosion mechanism (JJEM) can form a point-symmetric morphology that accounts for observed morphologies of about a dozen core-collapse supernovae ...
Jessica Braudo +3 more
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Shock and Vibration, 2021 Aiming at fault diagnosis of axial piston pumps, a new fusion method based on the extreme-point symmetric mode decomposition method (ESMD) and random forests (RFs) was proposed.
Lei Yafei +4 more
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Al-Qadisiyah Journal Of Pure Science, 2021 Cayley graph has been introduced by A . Cayley , which is point – symmetric . However in this paper , I have found another type of symmetric graph , which is not Cayley graph .
Nihad ABDEL - JALIL
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