Journal Articles - Natural Science - 2022

Permanent URI for this collection

Browse

Recent Submissions

Now showing 1 - 5 of 15
  • Publication
    A new metaheuristic algorithm: Shrimp and Goby association search algorithm and its application for damage identification in large-scale and complex structures
    ( 2022)
    Thanh Sang-To, Hoang Le-Minh, Magd Abdel Wahab, Cuong-Le Thanh
    "largescale global optimization problems. The performance of SGA is assessed using 13 benchmark high-dimensional functions, 10 classical benchmark functions, and several real-world engineering applications. For the first time, an efficient optimization approach for structural health monitoring (SHM) in truss-like structures is presented. The proposed approach is applied for damage identification of complex structures. A real structure, namely Canton Tower in Guangzhou, China, is served as an example for damage detection. Interestingly, this tower was the tallest structure in the world in 2009 with a height of 610 m. The great merit of this example is that it provides a real complex structure with a high-dimensional problem to assess the performance of SGA in the real world. The results show that SGA can deal with this problem effectively, at the same time, it operates better to escape from local optima with faster convergence rate than population-based algorithms."
  • Publication
    Some estimates for rough Hausdorff operators on the Heisenberg group
    ( 2022)
    Kieu Huu Dung, Dao Van Duong
    The purposes of this article is to establish some necessary and sufficient conditions for the boundedness of the rough Hausdorff operators on weighted Herz, central Morrey and Morrey–Herz spaces on the Heisenberg group. By applying the block decomposition method, the authors also obtain the boundedness of the rough Hausdorff operators on weighted Herz spaces for the case p 2 ð0; 1Þ.
  • Publication
    Boundedness of Hardy–Ces`aro operators on variable exponent Morrey–Herz spaces
    ( 2022)
    Kieu Huu Dung, Do Lu Cong Minh, Tran Thi Nang
    In this paper, we give the necessary and sufficient conditions for the boundedness of Hardy–Ces`aro operators on some weighted function spaces such as the weighted central Morrey, weighted local central Morrey, weighted non-local central Morrey, weighted Herz and weighted Morrey–Herz type spaces with variable exponent
  • Publication
    Enabling Cognitive Radio in NOMA Assisted Reconfigurable Intelligent Surfaces: Outage Performance Analysis
    ( 2022)
    Nguyễn Đức Nhân
    We have derived the closed-form expressions for outage probability (OP) at both the users and compared their performance in the presence of CR networks. The results show that, in the presence of CR, the number of meta-surfaces in RIS can significantly enhance the outage performance of the users. The comparison of both users’ performance has manifested that near users will have better outage performance compared to the far users.
  • Publication
    Judd-Ofelt analysis of Eu3+ and adjustable emission in Eu3+/Eu2+ co-doped sodium aluminosilicate glasses
    ( 2022)
    Nguyen Thi Quynh Lien
    ;
    Nguyen Ngoc Trac
    ;
    Phan Van Do
    ;
    Ho Van Tuyen
    Europium-doped sodium aluminosilicate glasses were synthesized by using the melt quenching technique. X-ray diffraction, photoluminescence spectra and luminescence decay of Eu3+ ions in glasses were investigated to estimate structural and optical properties of the prepared glasses. Phonon energies, Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4, 6) and radiative properties such as transition probability (A), radiative lifetime (τ), and branching ratio (βR) of Eu3+ ions in the prepared glasses were determined and Eu3+ emission may be suggested for suitable laser applications because of its high value of βR = 70.8%. The adjustable emission of Eu3+/Eu2+ from red light to blue light can be reached by heating the prepared glasses in H2 gas with various temperature and heating time. The reduction process from Eu3+ to Eu2+ ions in the glasses increases and maximum of Eu2+ emission shifts to the long wavelength with the increasing of temperature and heating time, that indicated the increase of the crystal field of sodium aluminosilicate heated in H2 gas.