Results 31 to 40 of about 1,635,411 (70)
NP-completeness of generalized multi-Skolem sequences
, 2007 A Skolem sequence is a sequence a1,a2,…,a2n (where ai∈A={1,…,n}), each ai occurs exactly twice in the sequence and the two occurrences are exactly ai positions apart. A set A that can be used to construct Skolem sequences is called a Skolem set.
Nordh, Gustav,
core +1 more source
New Difference Triangle Sets by a Field‐Programmable Gate Array‐Based Search Technique
Journal of Combinatorial Designs, Volume 34, Issue 1, Page 37-50, January 2026.ABSTRACT We provide some difference triangle sets with scopes that improve upon the best known values. These are found with purpose‐built digital circuits realized with field‐programmable gate arrays (FPGAs) rather than software algorithms running on general‐purpose processors.
Mohannad Shehadeh +2 more
wiley +1 more source
A New Fixed‐Point Framework for Nonexpansive and Averaged Mappings in Normed GE‐Algebras
Journal of Mathematics, Volume 2026, Issue 1, 2026.In this paper, we develop a systematic framework for studying fixed‐point theory in the setting of normed GE‐algebras. Building on the GE‐norm, we introduce and analyze nonexpansive mappings, α‐averaged mappings, and enriched contractions with respect to the quasimetric induced by the GE‐norm.
Prashant Patel +3 more
wiley +1 more source
WIREs Energy and Environment, Volume 14, Issue 4, December 2025.Graphical abstract illustrating the challenges, opportunities, and research gaps in decarbonizing ASEAN'S transport sector through electric vehicle (EV) and biofuel policy pathways. The framework highlights infrastructural, policy, and investment barriers alongside emerging opportunities from advanced biofuel technologies and supportive policy ...
Ohn Zin Lin +4 more
wiley +1 more source
The flat cover conjecture for monoid acts
Journal of the London Mathematical Society, Volume 112, Issue 6, December 2025.Abstract We prove that the Flat Cover Conjecture holds for the category of (right) acts over any right‐reversible monoid S$S$, provided that the flat S$S$‐acts are closed under stable Rees extensions. The argument shows that the class F$\mathcal {F}$‐Mono (S$S$‐act monomorphisms with flat Rees quotient) is cofibrantly generated in such categories ...
Sean Cox
wiley +1 more source
, 2008 A Skolem sequence is a sequence s1,s2,…,s2n (where si∈A={1,…,n}), each si occurs exactly twice in the sequence and the two occurrences are exactly si positions apart. A set A that can be used to construct Skolem sequences is called a Skolem set.
Nordh, Gustav,, Nordh, Gustav
core +1 more source
Gracefully labelled trees from Skolem and related sequences
, 2001 In this thesis we use Skolem sequences, hooked Skolem sequences, and periodic odd sequences to find graceful labellings of trees. -- Using a particular Skolem sequence of order n we will produce a graceful labelling of a certain tree on 2n vertices ...
Morgan, David
core +1 more source
Finite models for positive combinatorial and exponential algebra
Bulletin of the London Mathematical Society, Volume 57, Issue 11, Page 3380-3400, November 2025.Abstract We use high girth, high chromatic number hypergraphs to show that there are finite models of the equational theory of the semiring of non‐negative integers whose equational theory has no finite axiomatisation, and show this also holds if factorial, fixed base exponentiation and operations for binomial coefficients are adjoined.
Tumadhir Alsulami, Marcel Jackson
wiley +1 more source
The geometry and arithmetic of bielliptic Picard curves
Journal of the London Mathematical Society, Volume 112, Issue 5, November 2025.Abstract We study the geometry and arithmetic of the curves C:y3=x4+ax2+b$C \colon y^3 = x^4 + ax^2 + b$ and their associated Prym abelian surfaces P$P$. We prove a Torelli‐type theorem in this context and give a geometric proof of the fact that P$P$ has quaternionic multiplication by the quaternion order of discriminant 6.
Jef Laga, Ari Shnidman
wiley +1 more source
Small Methods, Volume 9, Issue 9, September 1, 2025.Schematic representation of band alignment and scanning transmission electron microscopy (STEM) image of Mo2S3‐WS2 nanocomposites. Abstract Addressing the energy crisis and environmental pollution demands the development of efficient electro‐ and photocatalysts capable of facilitating hydrogen production via water splitting.
Levna Chacko +8 more
wiley +1 more source