Results 1 to 10 of about 3,058 (119)
A 1 × 48 large‐scale multi‐mode fibre optical switch
IET Optoelectronics, Volume 16, Issue 6, Page 253-256, December 2022., 2022 Abstract A 1 × 48 large‐scale multi‐mode fibre (MMF) optical switch driven by a stepper motor is reported. The insertion loss is <1.42 dB, which can be further reduced to 1.02 dB after optimisation. With the employment of a corner cube prism in the optics, the device is characterised by good repeatability of <±0.01 dB.
Zhentian Shan, Zhujun Wan, Zhixiang Luo
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African Journal of Ecology, Volume 60, Issue 4, Page 1133-1142, December 2022., 2022 Abstract Artemisia afra was identified as an encroaching shrub in the Klipriviersberg Nature Reserve (KNR). Ecological factors that influence the encroachment of A. afra and its population structure were unknown, making it difficult to monitor and control the spread of the plant.
Kgalalelo T. A. Setshedi +2 more
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The minimum degree of minimal Ramsey graphs for cliques
Bulletin of the London Mathematical Society, Volume 54, Issue 5, Page 1827-1838, October 2022., 2022 Abstract We prove that sr(Kk)=O(k5r5/2)$s_r(K_k) = O(k^5 r^{5/2})$, where sr(Kk)$s_r(K_k)$ is the Ramsey parameter introduced by Burr, Erdős and Lovász in 1976, which is defined as the smallest minimum degree of a graph G$G$ such that any r$r$‐colouring of the edges of G$G$ contains a monochromatic Kk$K_k$, whereas no proper subgraph of G$G$ has this ...
John Bamberg +2 more
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ρ‐Einstein Solitons on Warped Product Manifolds and Applications
Journal of Mathematics, Volume 2022, Issue 1, 2022., 2022 The purpose of this research is to investigate how a ρ‐Einstein soliton structure on a warped product manifold affects its base and fiber factor manifolds. Firstly, the pertinent properties of ρ‐Einstein solitons are provided. Secondly, numerous necessary and sufficient conditions of a ρ‐Einstein soliton warped product manifold to make its factor ρ ...
Nasser Bin Turki +5 more
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Conformally Flat Pseudoprojective Symmetric Spacetimes in fR,G Gravity
Advances in Mathematical Physics, Volume 2022, Issue 1, 2022., 2022 Sufficient conditions on a pseudoprojective symmetric spacetime (PPS)n whose Ricci tensor is of Codazzi type to be either a perfect fluid or Einstein spacetime are given. Also, it is shown that a (PPS)n is Einstein if its Ricci tensor is cyclic parallel. Next, we illustrate that a conformally flat (PPS)n spacetime is of constant curvature.
Uday Chand De +4 more
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Chloroplast Genome Evolution and Species Identification of Styrax (Styracaceae)
BioMed Research International, Volume 2022, Issue 1, 2022., 2022 The genus Styrax L. consists of approximately 130 species distributed in the Americas, eastern Asia, and the Mediterranean region. The phylogeny and evolutionary history of this genus are not clear. Knowledge of the phylogenetic relationships and the method for species identification will be critical for the evolution of this genus.
Yun Song +5 more
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Shock and Vibration, Volume 2021, Issue 1, 2021., 2021 Distributed‐drive electric vehicles constitute an important research direction for the future development of electric vehicles. In this regard, the integrated suspension wheel‐side drive system has considerable development potential because it can address the lack of driving smoothness and the grounding deterioration caused by the excessive unsprung ...
Wen Lu +3 more
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2-elements in an Autotopism Group of a Semifield Projective Plane
Известия Иркутского государственного университета: Серия "Математика", 2022 We investigate the well-known hypothesis of D.R. Hughes that the full collineation group of non-Desarguesian semifield projective plane of a finite order is solvable (the question 11.76 in Kourovka notebook was written down by N.D. Podufalov). The spread
Olga Kravtsova
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A New Class of Contact Pseudo Framed Manifolds with Applications
International Journal of Mathematics and Mathematical Sciences, Volume 2021, Issue 1, 2021., 2021 In this paper, we introduce a new class of contact pseudo framed (CPF)‐manifolds (M, g, f, λ, ξ) by a real tensor field f of type (1,1), a real function λ such that f3 = λ2f where ξ is its characteristic vector field. We prove in our main Theorem 2 that M admits a closed 2‐form Ω if λ is constant.
K. L. Duggal, Luca Vitagliano
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On Distance in Some Finite Planes and Graphs Arising from Those Planes
Journal of Mathematics, Volume 2021, Issue 1, 2021., 2021 In this paper, affine and projective graphs are obtained from affine and projective planes of order pr by accepting a line as a path. Some properties of these affine and projective graphs are investigated. Moreover, a definition of distance is given in the affine and projective planes of order pr and, with the help of this distance definition, the ...
I. Dogan, A. Akpinar, Ahmet Sinan Cevik
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