Results 71 to 80 of about 637 (264)
Energy Science &Engineering, EarlyView.This paper aims to provide a robust design approach for HAWTs operating in shear flow. This study fills a critical research gap by integrating BEM and vortex theories for blade design in non‐homogeneous inflow conditions. The authors of the paper made an effort to develop and test an experimentally unsophisticated model of a turbine working in shear ...
Agnieszka Dorota Woźniak +2 more
wiley +1 more source
On the Composition of Rotations in $\mathbb{R}^3$
Communications in Advanced Mathematical SciencesEuler stated that the composition of two successive rotations is also a rotation, but did not solve the problem of finding the resultant (axis and angle of rotation) of the composition. It is Rodrigues who solved it.
François Dubeau
doaj +1 more source
Energy Science &Engineering, EarlyView.In this study, the key control mechanism of surrounding rock stability is revealed by theoretical analysis and UDEC‐Trigon numerical simulation method, aiming at the problem that oil shale roof is prone to separation and slip deformation under complex stress.
Jiang Xiao +5 more
wiley +1 more source
UNUSUAL FORMULAE FOR THE EULER CHARACTERISTIC [PDF]
Journal of Knot Theory and Its Ramifications, 2002 Everyone knows that the Euler characteristic of a combinatorial manifold is given by the alternating sum of its numbers of simplices. It is shown that there are other linear combinations of the numbers of simplices which are combinatorial invariants, but that all such invariants are multiples of the Euler characteristic.
openaire +2 more sources
Robust Control Using a Matrix Converter to Enhance Wind Turbine Systems
Energy 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
On Some Multipliers Related to Discrete Fractional Integrals
MathematicsThis paper explores the properties of multipliers associated with discrete analogues of fractional integrals, revealing intriguing connections with Dirichlet characters, Euler’s identity, and Dedekind zeta functions of quadratic imaginary fields ...
Jinhua Cheng
doaj +1 more source
International Journal for Numerical Methods in Fluids, EarlyView.We introduce an efficient open‐source numerical framework for the automated search for the placements of injection and production wells in hot fracture‐controlled reservoirs that sustainably optimize geothermal energy production. We model the reservoirs as discrete fracture networks in 3D. The fluid flow and heat transport in the reservoirs are modeled
Ondřej Pártl, Ernesto Meneses Rioseco
wiley +1 more source
Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver
International 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
Literature Review of Applying Visual Method to Understand Mathematics
MATEC Web of Conferences, 2015 As a new method to understand mathematics, visualization offers a new way of understanding mathematical principles and phenomena via image thinking and geometric explanation.
Yu Xiaojuan
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The Independence Ratio of 4‐Cycle‐Free Planar Graphs
Journal of Graph Theory, EarlyView.ABSTRACT We prove that every n $n$‐vertex planar graph G $G$ with no triangle sharing an edge with a 4‐cycle has independence ratio n ∕ α ( G ) ≤ 4 − ε $n\unicode{x02215}\alpha (G)\le 4-\varepsilon $ for ε = 1 ∕ 30 $\varepsilon =1\unicode{x02215}30$. This result implies that the same bound holds for 4‐cycle‐free planar graphs and planar graphs with no ...
Tom Kelly +3 more
wiley +1 more source