Results 71 to 80 of about 840,116 (317)

A fixed point theorem for contraction mappings

International Journal of Mathematics and Mathematical Sciences, 1982
Let S be a closed subset of a Banach space E and f:S→E be a strict contraction mapping. Suppose there exists a mapping h:S→(0,1] such that (1−h(x))x+h(x)f(x)∈S for each x∈S. Then for any x0∈S, the sequence {xn} in S defined by xn+1=(1−h(xn))xn+h(xn)f(xn),
V. M. Sehgal
doaj   +1 more source

Characterizing Emerging Detector Materials for Low‐Dose X‐Ray Imaging

Advanced Materials, EarlyView.
X‐ray medical imaging requires detectors that deliver images at as low as reasonably possible dose. This perspective outlines a universal characterization framework of X‐ray imaging detectors, suitable for both emerging semiconductor and scintillator materials, introduces a novel unified figure of merit that links dose with resolution, and offers an ...
Kostiantyn Sakhatskyi, Vitalii Bartosh, Ying Zhou, Gebhard J. Matt, Jingjing Zhao, Sergii Yakunin, Jinsong Huang, Maksym V. Kovalenko   +7 more
wiley   +1 more source

Demonstration of 3D‐Printed Optical Antennas for High‐Speed Optical Wireless Communication Using Market‐Ready Materials

Advanced Materials Technologies, EarlyView.
The feasibility of 3D‐printed optical antennas using commercial, non‐optical materials for Optical Wireless Communications (OWC) is demonstrated. This study combines spectral analysis, anisotropy effects, and telecom‐relevant optical measurements, revealing promising performance and novel insights for low‐cost, customizable photonic components in ...
Mauro Aresti, Marco Meucci, Paolo Foggi, Caterina Credi, Satoshi Iketani, Cristiana Lofrumento, Jacopo Catani   +6 more
wiley   +1 more source

Note on KKM maps and applications

Fixed Point Theory and Applications, 2006
We apply the KKM technique to study fixed point theory, minimax inequality and coincidence theorem. Some new results on Fan-Browder fixed point theorem, Fan's minimax theorem and coincidence theorem are obtained.
B. S. Lee, J. K. Kim, Y. J. Cho, Y. Q. Chen   +3 more
doaj   +1 more source

On the Brouwer fixed point theorem

Topology and its Applications, 2002
The author studies the Brouwer-type fixed point theorem for multivalued mappings which are continuous with respect to the Borsuk continuity metric and have spheric-type values. By using deep topological methods, the fixed-point problem is expressed in terms of sphere bundles over manifolds. New methods in the fixed-point problem are presented.
openaire   +2 more sources

Ultrasound‐Powered, Battery‐Free Implants via Triboelectric Energy Harvesting

Advanced Materials Technologies, EarlyView.
Ultrasound‐driven triboelectric nanogenerators (US‐TENGs) present a promising approach to battery‐free implants by combining body‐safe ultrasound with the material and structural versatility of TENGs. This review categorizes current US‐TENG research into long‐term and transient short‐term applications and discusses key challenges in materials, device ...
Youngwook Chung, Saswat Choudhury, Young‐Jun Kim, In‐Yong Suh, Keren Dai, Sang‐Woo Kim   +5 more
wiley   +1 more source

Step Function in Momentum Space by a Metagrating

Advanced Optical Materials, EarlyView.
This work demonstrates how the symmetry of the angular transmittance could be broken by a metagrating where the diffraction channels alleviate the requirement for enforcing absorbance. The metagrating retroreflects incident waves with positive incidence angles and transmits waves with negative incidence angles.
Mahmoud A. A. Abouelatta, Sergejs Boroviks, Olivier J. F. Martin, Karim Achouri   +3 more
wiley   +1 more source

Optical Poling of Ferroelectric Liquids

Advanced Optical Materials, EarlyView.
The optical control of size and shape of polar domains in ferroelectric nematic liquid crystal cells is reported. In sufficiently thin samples, light irradiation induces the formation of a novel singular spiral‐shape arrangement of the polar director as a response to localized illumination.
Stefano Marni, Raouf Barboza, Noel Clark, Tommaso Bellini, Liana Lucchetti   +4 more
wiley   +1 more source

A fractional order Monkeypox model with protected travelers using the fixed point theorem and Newton polynomial interpolation. [PDF]

Healthc Anal (N Y), 2023
Adom-Konadu A, Bonyah E, Sackitey AL, Anokye M, Asamoah JKK.   +4 more
europepmc   +1 more source

The equivariant Lefschetz fixed point theorem for proper cocompact G-manifolds

, 2001
Suppose one is given a discrete group G, a cocompact proper G-manifold M, and a G-self-map f of M. Then we introduce the equivariant Lefschetz class of f, which is globally defined in terms of cellular chain complexes, and the local equivariant Lefschetz
Lueck, Wolfgang, Rosenberg, Jonathan
core   +2 more sources