Results 91 to 100 of about 777 (268)

Lightlike Submanifolds of a Semi-Riemannian Manifold of Quasi-Constant Curvature

Journal of Applied Mathematics, 2012
We study the geometry of lightlike submanifolds (𝑀,𝑔,𝑆(𝑇𝑀),𝑆(𝑇𝑀⟂)) of a semi-Riemannian manifold (𝑀,̃𝑔) of quasiconstant curvature subject to the following conditions: (1) the curvature vector field ζ of 𝑀 is tangent to 𝑀, (2) the screen distribution 𝑆(
D. H. Jin, J. W. Lee
doaj   +1 more source

Sliding Mode Control in Aerospace Applications: A Survey

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Sliding mode control (SMC) enjoys robustness to matched and unmatched (in the case of minimum phase input‐output dynamics) bounded perturbations, and finite time convergence. Second‐order and higher‐order sliding mode control systems (2‐SMC/HOSMC) retain all the advantages of sliding mode control, but in addition can be applied to systems of ...
Yuri Shtessel, Christopher Edwards
wiley   +1 more source

On minimal hypersurfaces of nonnegatively Ricci curved manifolds

International Journal of Mathematics and Mathematical Sciences, 1993
We consider a complete open riemannian manifold M of nonnegative Ricci curvature and a rectifiable hypersurface ∑ in M which satisfies some local minimizing property. We prove a structure theorem for M and a regularity theorem for ∑.
Yoe Itokawa
doaj   +1 more source

Evaluating the Role of Social Capital for the Design of Sustainable River Governance Strategies: The Case of Tagus River

Sustainable Development, EarlyView.
ABSTRACT This study examines the role of social capital in designing and implementing more effective governance strategies to improve the state of the Tagus River's significantly deteriorated middle reach (Spain). We employed social network analysis (SNA) to evaluate the bonding, bridging and linking social capital and the quality of stakeholder ...
Leticia Blázquez, Juan A. García, José M. Bodoque   +2 more
wiley   +1 more source

Climate Crisis, Human Mobility and Security Challenges in the MENA Region: Implications for Sustainable Development and Regional Stability

Sustainable Development, EarlyView.
ABSTRACT This study examines the interplay between climate change, violent conflict and forced migration in the Middle East and North Africa (MENA), focusing on asylum flows to the European Union (EU). By integrating high‐resolution climate, conflict and socioeconomic data spanning 2000 to 2023, we develop a comprehensive empirical framework to ...
Shifa Mathbout, George Boustras, Pierantonios Papazoglou, Javier Martin‐Vide, Joan A. Lopez‐Bustins   +4 more
wiley   +1 more source

Ricci Solitons on Riemannian Hypersurfaces Generated by Torse-Forming Vector Fields in Riemannian and Lorentzian Manifolds

Axioms
In this paper, we examine torse-forming vector fields to characterize extrinsic spheres (that is, totally umbilical hypersurfaces with nonzero constant mean curvatures) in Riemannian and Lorentzian manifolds.
Norah Alshehri, Mohammed Guediri
doaj   +1 more source

Influence of natural fibers on physical, mechanical, and fire‐resistant properties of microconcrete

Structural Concrete, EarlyView.
Abstract This study examined the influence of natural fibers on the physical, mechanical, and fire‐resistant properties of microconcrete, in comparison with conventional polypropylene fibers used in cement composites. The fibers were characterized by FTIR and TGA/DSC to assess their composition and thermal stability, and FTIR was also performed after ...
Ivanka Netinger Grubeša, Sandra Juradin, Silvija Mrakovčić, Lidija Radovanović, Milica Vasić, Huseyin Bilgin   +5 more
wiley   +1 more source

Landscape factors influencing predation on capercaillie nests by two competing mesopredators: pine marten and red fox

Wildlife Biology, EarlyView.
Predation by pine martens Martes martes and red foxes Vulpes vulpes is an important factor influencing the population dynamics of capercaillie Tetrao urogallus. However, there is a knowledge gap regarding the relative effects of these mesopredators on the reproductive success of capercaillie. To better understand how various landscape factors influence
Siow Yan Jennifer Angoh, Scott Michael Brainerd, Olivier Devineau, Morten Odden, Torfinn Jahren   +4 more
wiley   +1 more source

Modelling the Four‐Dimensional Power Line Sag Dynamics by Point Signature in Time‐Series Synthetic‐Aperture Radar Images

High Voltage, EarlyView.
ABSTRACT Power lines in synthetic‐aperture radar (SAR) images are reflected as point signatures, which fluctuate annually in both the azimuth and range directions. A novel framework is proposed in this paper to evaluate the four‐dimensional dynamic status of power line sag using those point signatures in time‐series SAR images.
Sijie Ma, Tao Li, Mahdi Motagh, Yan Liu, Yangmao Wen   +4 more
wiley   +1 more source

Hurricane‐induced risk contagion in commercial real estate: Evidence from Hurricane Sandy

Real Estate Economics, EarlyView.
Abstract This study examines how hurricane‐induced destruction affects the prices of nearby undamaged commercial real estate properties, using Hurricane Sandy as a natural experiment. Using Real Capital Analytics transaction records spatially merged with Federal Emergency Management Agency building‐level damage data, we empirically employ a difference ...
Lu Fang, Lingxiao Li, David Scofield, Abdullah Yavas   +3 more
wiley   +1 more source