Results 91 to 100 of about 32,087 (238)

Upper bound limit analysis of coral reef limestone cavern roof stability incorporating a tension‐shear failure mechanism with tensile‐strength cut‐off

open access: yesDeep Underground Science and Engineering, EarlyView.
For the roof of coral reef limestone caverns, a novel tension‐shear composite failure mechanism was developed. The most critical tensile crack model was identified using a hybrid optimization algorithm, and the stability of the cavern roof was analyzed accordingly.
Dongsheng Xu, Chenxu Li, Chuantan Hou
wiley   +1 more source

Robust Control Using a Matrix Converter to Enhance Wind Turbine Systems

open access: yesEnergy Science &Engineering, EarlyView.
This study uses a more efficient and effective solution to improve the operational performance of a wind turbine‐based power system. This system uses a doubly fed induction generator and relies on a matrix converter and fractional‐order proportional–integral controller.
Sihem Ghoudelbourk   +4 more
wiley   +1 more source

Jet Flow Field Analysis of Convergent‐Divergent Nozzle for Hydraulic Perforation for Natural Gas Hydrates

open access: yesEnergy Science &Engineering, EarlyView.
Combining the nozzle structure and wellbore size of the second natural gas hydrate trial production, the CFD is employed to analyze the internal and external flow fields of convergent–divergent cavitation nozzle. Analyzing the influence of various structural parameters of the nozzle on its jet performance, and the nozzle configuration with optimal jet ...
Wang Yingsheng   +5 more
wiley   +1 more source

Mathematical model of rigid body motion for the research of the “Dzhanibekov's effect”

open access: yesPropulsion and Power Research
An alternative set of angles for determining the position of a rigid body, instead of Euler angles, is proposed. These angles were used to model the motion of a rigid body (rotor) rotating around a horizontal axis.
Oleksandr I. Tarasenko   +2 more
doaj   +1 more source

Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver

open access: yesInternational Journal for Numerical Methods in Fluids, EarlyView.
A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley   +1 more source

On Kotzig's Perfect Set Problem of Hamiltonian Cycle Decompositions of the Complete Graph

open access: yesJournal of Combinatorial Designs, EarlyView.
ABSTRACT A Hamiltonian cycle decomposition (HCD) of K n ${K}_{n}$ is a set of Hamiltonian cycles in which each 1‐path of K n ${K}_{n}$ appears exactly once. A Dudeney set of K n ${K}_{n}$ is a set of Hamiltonian cycles in which each 2‐path of K n ${K}_{n}$ appears exactly once.
Nobuaki Mutoh
wiley   +1 more source

On Oriented Colourings of Graphs on Surfaces

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT For an oriented graph G $G$, the least number of colours required to oriented colour G $G$ is called the oriented chromatic number of G $G$ and denoted χ o ( G ) ${\chi }_{o}(G)$. For a non‐negative integer g $g$ let χ o ( g ) ${\chi }_{o}(g)$ be the least integer such that χ o ( G ) ≤ χ o ( g ) ${\chi }_{o}(G)\le \unicode{x0200A}{\chi }_{o}(g)
Alexander Clow
wiley   +1 more source

Analysis of the COVID-19 pandemic and prediction with numerical methods

open access: yesInternational Journal of Mathematics for Industry
Coronavirus spreads worldwide with various symptoms and strains such as COVID-19, SARS, MERS. Outbreak and prevention of the coronavirus can be studied by many mathematical models like SIR, SEIR and SEIQDR. In this paper, we employed Euler’s method based
M. M. Singh   +3 more
doaj   +1 more source

Signed Projective Cubes, a Homomorphism Point of View

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT The (signed) projective cubes, as a special class of graphs closely related to the hypercubes, are on the crossroad of geometry, algebra, discrete mathematics and linear algebra. Defined as Cayley graphs on binary groups, they represent basic linear dependencies.
Meirun Chen   +2 more
wiley   +1 more source

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