Search results for "algebra"
showing 10 items of 4129 documents
Test module filtrations for unit $F$-modules
2015
We extend the notion of test module filtration introduced by Blickle for Cartier modules. We then show that this naturally defines a filtration on unit $F$-modules and prove that this filtration coincides with the notion of $V$-filtration introduced by Stadnik in the cases where he proved existence of his filtration. We also show that these filtrations do not coincide in general. Moreover, we show that for a smooth morphism $f: X \to Y$ test modules are preserved under $f^!$. We also give examples to show that this is not the case if $f$ is finite flat and tamely ramified along a smooth divisor.
A criterion for extending morphisms from open subsets of smooth fibrations of algebraic varieties
2021
Abstract Given a smooth morphism Y → S and a proper morphism P → S of algebraic varieties we give a sufficient condition for extending an S-morphism U → P , where U is an open subset of Y, to an S-morphism Y → P , analogous to Zariski's main theorem.
The Dunkl–Williams constant, convexity, smoothness and normal structure
2008
Abstract In this paper we exhibit some connections between the Dunkl–Williams constant and some other well-known constants and notions. We establish bounds for the Dunkl–Williams constant that explain and quantify a characterization of uniformly nonsquare Banach spaces in terms of the Dunkl–Williams constant given by M. Baronti and P.L. Papini. We also study the relationship between Dunkl–Williams constant, the fixed point property for nonexpansive mappings and normal structure.
Boundedness and spectral invariance for standard pseudodifferential operators on anisotropically weighted LP-Sobolev spaces
1990
It is shown that pseudodifferential operators with symbols in the standard classes S ρ,δ m (ℝn) define bounded maps between large classes of weighted LP-Sobolev spaces where the growth of the weight does not have to be isotropic. Moreover, the spectrum is independent of the choice of the space.
Norm continuity and related notions for semigroups on Banach spaces
1996
We find some conditions on a c0-semigroup on a Banach space and its resolvent connected with the norm continuity of the semigroup. We use them to get characterizations of norm continuous, eventually norm continuous and eventually compact semigroups on Hilbert spaces in terms of the growth of the resolvent of their generator.
Testing a model for the monitoring of worked-out algebra-problem examples: from behaviours to outcomes on a math task
2021
This study aimed at testing an extension of a theoretical model for the metacognitive monitoring mechanism implied in the detection of inconsistencies when the information provided includes abstract symbols in addition to plain text. Ninety-four postgraduates of STEM specialities were asked to read a worked-out algebra-problem example and to report any incoherence, inconsistency, or error detected in the statement or in the solving procedure. A set of model inspired indexes was defined to describe participants¿ behaviour along the task. The Read & Answer software was used to record online individual processing data and participants¿ reports. Results supported model predictions. Indexes corr…
Luigi Cremona’s Years in Bologna: From Research to Social Commitment
2011
Luigi Cremona (1830–1903), unanimously considered to be the man who laid the foundations of the prestigious Italian school of Algebraic Geometry, was active at the University of Bologna from October 1860, when assigned by the Minister Terenzio Mamiani (1799–1885) to cover the Chair of Higher Geometry, until September 1867 when Francesco Brioschi (1824–1897) called him to the Politecnico di Milano. The “Bolognese years” were Cremona’s richest and most significant in terms of scientific production, and, at the same time, were the years when he puts the basis for its most important interventions in the social and political life of the “newborn” kingdom of Italy. In this article we present thes…
La garantía social y la autoejecución del derecho al trabajo: La España post-crisis (2007-2017)
2017
What happens when neither the institutions nor the official law are able to cover the basic needs of subsistence and a decent life of an individual or group of people? Do they have, in these situations, a right to self-enforceability of rights? This article will analyze this issue and the main debates associated with it, focusing on the different experiences and types of self-enforceability of the right to work that have occurred in Spain during the last years following the 2007-2008. In particular, it will be analyzed different cases of factory recovery and land occupation and self-management looking at the differences between these two forms of self-executing of the right to work.
Positioning flexibly scheduled ECEC in the chain of childcare by parents working non-standard hours
2022
This study examined how Finnish parents working non-standard hours (N=18) positioned institutional flexibly scheduled early childhood education and care (ECEC) as a link in their chain of childcare. Interview data, analysed following the principles of discursive psychology, yielded three discourses on flexibly scheduled ECEC: the discourse of the child’s best interest, the discourse of the labour market, and the discourse of equality of opportunity for the child. Flexibly scheduled ECEC was positioned in these discourses either as the last resort option for childcare, a safe haven for the child, a societal service enabling parents to work during non-standard hours or as a place for children…
Artificial Vision and Soft Computing
1999
The term soft-computing has been introduced by Zadeh in 1994. Soft-computing provides an appropriate paradigm to program malleable and smooth concepts. For example, it can be used to introduce flexibility in artificial systems to improve their Intelligent Quotient. The aim of this paper is to describe the applicability of soft-computing to artificial vision problems. Good performance of this approach is assured by the fact that digital images are examples of fuzzy entities, where shapes are not always describable by exact equations and their approximation can be very complex.