Results 51 to 60 of about 4,477 (212)
Lie and Noether symmetries of geodesic equations and collineations
, 2011 The Lie symmetries of the geodesic equations in a Riemannian space are computed in terms of the special projective group and its degenerates (affine vectors, homothetic vector and Killing vectors) of the metric.
A. Barnes +20 more
core +1 more source
2‐Conformal Vector Fields on the Model Sol Space and Hyperbolic Ricci Solitons
Journal of Mathematics, Volume 2025, Issue 1, 2025.In this study, we present the notion of 2‐conformal vector fields on Riemannian and semi‐Riemannian manifolds, which are an extension of Killing and conformal vector fields. Next, we provide suitable vector fields in Sol space that are 2‐conformal. A few implications of 2‐conformal vector fields in hyperbolic Ricci solitons are investigated.
Rawan Bossly +3 more
wiley +1 more source
A Theoretical Investigation of Channel Wave Multipath Propagation in a Coal Seam
Mathematical Problems in Engineering, Volume 2019, Issue 1, 2019., 2019 This study investigates the mechanism of channel wave multipath propagation to determine features of a channel wave in a coal seam. For this purpose, deduction formulas were used for different time delays and propagation paths and, subsequently, a multipath fading channel wave pattern was built. MATLAB software was used to simulate the model.
Yinjing Guo +4 more
wiley +1 more source
, 2003 As a rule in General Relativity the spacetime metric fixes the Einstein tensor and through the Field Equations (FE) the energy-momentum tensor. However one cannot write the FE explicitly until a class of observers has been considered.
Apostolopoulos, Pantelis S. +1 more
core +1 more source
Reply to Collins and Altman [PDF]
European Journal of Cardio-Thoracic Surgery, 2012 We are pleased that EuroSCORE II [1] continues to generate interest and are happy to respond to concerns about its development and evaluation [2]. We find very little to disagree with in the points raised by Collins and Altman [3], but are not convinced that their suggested alternative analysis would have resulted in materially different results.
Linda D, Sharples, Samer A M, Nashef
openaire +2 more sources
Irrigation and Drainage, Volume 73, Issue 3, Page 988-1009, July 2024.Abstract In this study, the performance of a one‐source surface energy balance (OSEB) remote sensing (RS) of actual crop evapotranspiration (ETa), incorporating data from different spaceborne, airborne and proximal multispectral data, was evaluated. The RS platforms in this study included Landsat‐8 (30 m pixel size), Sentinel‐2 (10 m), Planet CubeSat ...
Edson Costa‐Filho +2 more
wiley +1 more source
Incremental Localization Algorithm Based on Regularized Iteratively Reweighted Least Square
Foundations of Computing and Decision Sciences, 2016 Incremental localization algorithm is a distributed localization method with excellent characteristics for wireless network. However, its estimated result is generally influenced by the heteroscedasticity arising from cumulative errors and the ...
Yan Xiaoyong +4 more
doaj +1 more source
A Co-Point Mapping-Based Approach to Drivable Area Detection for Self-Driving Cars
Engineering, 2018 The randomness and complexity of urban traffic scenes make it a difficult task for self-driving cars to detect drivable areas. Inspired by human driving behaviors, we propose a novel method of drivable area detection for self-driving cars based on fusing
Ziyi Liu, Siyu Yu, Nanning Zheng
doaj +1 more source
Riemann Solitons and Ricci Bi-Conformal Vector Fields on 4-Dimensional Oscillator Group
MathematicsWe consider Riemann soliton vector fields and Ricci bi-conformal vector fields on the oscillator group. We prove that the oscillator group admits Riemann solitons. Subsequently, we provide a complete classification of all Ricci bi-conformal vector fields
Bang-Yen Chen +3 more
doaj +1 more source
Matrix spread sets of p-primitive semifield planes
International Journal of Mathematics and Mathematical Sciences, 1997 In this article we present the matrix spread sets of the p-primitive planes of order p4 where p=3,5,7,11.
M. Cordero
doaj +1 more source