Results 41 to 50 of about 1,504 (198)

Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley   +1 more source

Facial Expression Recognition Based on Local Binary Patterns and Kernel Discriminant Isomap

Sensors, 2011
Facial expression recognition is an interesting and challenging subject. Considering the nonlinear manifold structure of facial images, a new kernel-based manifold learning method, called kernel discriminant isometric mapping (KDIsomap), is proposed ...
Xiaoming Zhao, Shiqing Zhang
doaj   +1 more source

The Effect of COVID-19 Pandemic on Emitted PM2.5 in Urban Road Networks: Using Loop Data and Kriging Method for Passenger Cars in the Central Part of the City of Lodz

Aerosol and Air Quality Research, 2022
In this paper, the effect of the COVID-19 pandemic on the emission of PM2.5 generated by passenger cars is investigated. First, traffic data collected from the inductive loop sensors is analyzed.
Marta Borowska-Stefańska, Michał Kowalski, Paulina Kurzyk, Alireza Sahebgharani, Szymon Wiśniewski   +4 more
doaj   +1 more source

Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT A (2‐dimensional) realisation of a graph G $G$ is a pair ( G , p ) $(G,p)$, where p $p$ maps the vertices of G $G$ to R 2 ${{\mathbb{R}}}^{2}$. A realisation is flexible if it can be continuously deformed while keeping the edge lengths fixed, and rigid otherwise.
Katie Clinch, Dániel Garamvölgyi, John Haslegrave, Tony Huynh, Jan Legerský, Anthony Nixon   +5 more
wiley   +1 more source

Closed Conformal Vector Fields in Gradient Einstein Solitons

Axioms
We investigate gradient Einstein solitons admitting closed conformal vector fields. Under constant scalar curvature, we establish rigidity results showing that complete solitons with non-parallel closed conformal vector fields are isometric to Euclidean ...
Norah Alshehri, Fatin Nabila Abd Latiff, Mukarram Ali, Akram Ali   +3 more
doaj   +1 more source

Effect of Spanish-Style Table Olive Processing on Fatty Acid Profile: A Compositional Data Analysis (CoDA) Approach

Foods, 2022
This manuscript considers that the composition of Manzanilla and Hojiblanca fats are compositional data (CoDa). Thus, the work applies CoDa analysis (CoDA) to investigate the effect of processing and packaging on the fatty acid profiles of these ...
Antonio Garrido-Fernández, Amparo Cortés-Delgado, Antonio López-López   +2 more
doaj   +1 more source

Spatiotemporal dynamics of brain function network during proprioception rehabilitation after anterior cruciate ligament reconstruction: A randomized trial

Knee Surgery, Sports Traumatology, Arthroscopy, EarlyView.
The improvement of proprioceptive function after ACLR is related to the optimization of spatiotemporal dynamics of SM, CC, DM, CB and VI functional networks. Rehabilitation optimization can incorporate visual–cognitive dual‐task exercises. Abstract Purpose In this study, we aimed to examine the dynamic functional network connectivity (dFNC) patterns ...
Xiaoyun Zhuang, Chunmei Sui, Xuesong Han, Xiaoying Liu, Xiaoyang Wang, Xiumei Zhu, Ming Xu, Yin Qin   +7 more
wiley   +1 more source

Visibility and Intersection Density for Boolean Models in Hyperbolic Space

Mathematische Nachrichten, EarlyView.
ABSTRACT For Poisson particle processes in hyperbolic space we introduce and study concepts analogous to the intersection density and the mean visible volume, which were originally considered in the analysis of Boolean models in Euclidean space. In particular, we determine a necessary and sufficient condition for the finiteness of the mean visible ...
Tillmann Bühler, Daniel Hug, Christoph Thäle   +2 more
wiley   +1 more source

Some Rigidity Results Related to Conformal Vector Fields

Mathematics
This article explores properties of conformal vector fields on a Riemannian manifold, focusing on conditions that lead to the manifold being isometric to the Euclidean space. Given a conformal vector ζ with conformal factor σ on a Riemannian manifold N,g,
Hanan Alohali, Sharief Deshmukh
doaj   +1 more source

Kernel Bounds for Parabolic Operators Having First‐Order Degeneracy at the Boundary

Mathematische Nachrichten, EarlyView.
ABSTRACT We study kernel estimates for parabolic problems governed by singular elliptic operators ∑i,j=1N+1qijDij+cDyy,cγ+1>0,γ=qN+1,N+1,$$\begin{equation*} \sum _{i,j=1}^{N+1}q_{ij}D_{ij}+c\frac{D_y}{y},\qquad \frac{c}{\gamma }+1>0, \quad \gamma =q_{N+1,N+1}, \end{equation*}$$in the half‐space R+N+1={(x,y):x∈RN,y>0}$\mathbb {R}^{N+1}_+=\lbrace (x,y ...
L. Negro, C. Spina
wiley   +1 more source