Search results for "REPRESENTATION"

Learning About Forces Using Multiple Representations

2017

We present two research-based interventions to measure upper secondary student learning of forces using multiple representations (MRs). The first intervention is the Representational Variant of the Force Concept Inventory (R-FCI) – a multiple-choice test for evaluating students’ representational consistency in answering triplets of isomorphic items in the context of forces. The second intervention is an interaction diagram (ID) – a visual representation that helps students to identify forces resulting from interactions between two objects. Students’ representational consistency on the R-FCI pre-test correlated with their normalised learning gain on the Force Concept Inventory (FCI) suggesti…

Models and Phenomena: Bas van Fraassen’s Empiricist Structuralism

2013

Bas van Fraassen’s recent endorsement of empiricist structuralism is based on a particular approach to representation. He sharply distinguishes between what makes a scientific model M a successful representation of its target T from what makes M a representation of T and not of some other different target T’. van Fraassen maintains that embedment (i.e.: a particular sort of isomorphism which relates structures) gives the answer to the first question while the user’s decision to employ model M to represent T accounts for the representational link. After discussing the rationale for this approach, I defend that indexical constraints like those favoured by van Fraassen cannot be the last word …

Density as a constraint and the separation of internal excitation energy in TDHF

1985

We present a fast and efficient constrained Hartree-Fock iteration scheme which constraints the complete density distribution to remain constant. The scheme is particularly suited to a coordinate- or momentum-space representation. The technique is applied to separate the collective and the internal energy in a propagating TDHF state. We study the behavior of these two energies in an16O+16O collision.

Mothers’ self-representations and representations of childhood on social media

2023

Funding Information: This work was supported by Kone Foundation, Academy of Finland (#320370), Strategic Research Council (#327237), Strategic Research Council (#327395), Intimacy in Data-driven Culture (IDA). The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Publisher Copyright: © 2023, Minna Kallioharju, Terhi-Anna Wilska and Annamari Vänskä. Purpose: The purpose of this paper is to examine mothers’ social media accounts that focus on children’s fashion. The authors probed children’s fashion photo practices as representations of the mothers’ extended self and the kind of childhood representations produce…

CONTENT-BASED ANALYSIS OF MODES IN DESIGN ENGINEERING

2007

Orbits of bounded bijective operators and Gabor frames

2020

This paper is a contribution to frame theory. Frames in a Hilbert space are generalizations of orthonormal bases. In particular, Gabor frames of $L^2(\mathbb{R})$, which are made of translations and modulations of one or more windows, are often used in applications. More precisely, the paper deals with a question posed in the last years by Christensen and Hasannasab about the existence of overcomplete Gabor frames, with some ordering over $\mathbb{Z}$, which are orbits of bounded operators on $L^2(\mathbb{R})$. Two classes of overcomplete Gabor frames which cannot be ordered over $\mathbb{Z}$ and represented by orbits of operators in $GL(L^2(\mathbb{R}))$ are given. Some results about opera…

Efficient simulation of the random-cluster model

2013

The simulation of spin models close to critical points of continuous phase transitions is heavily impeded by the occurrence of critical slowing down. A number of cluster algorithms, usually based on the Fortuin-Kasteleyn representation of the Potts model, and suitable generalizations for continuous-spin models have been used to increase simulation efficiency. The first algorithm making use of this representation, suggested by Sweeny in 1983, has not found widespread adoption due to problems in its implementation. However, it has been recently shown that it is indeed more efficient in reducing critical slowing down than the more well-known algorithm due to Swendsen and Wang. Here, we present…

LA CONTRATTAZIONE COLLETTIVA NEGLI STATI UNITI DAL WAGNER ACT AI NOSTRI GIORNI

2016

LA CONTRATTAZIONE COLLETTIVA NEGLI STATI UNITI. DAL WAGNER ACT AI NOSTRI GIORNI. — Riassunto. Il presente lavoro analizza la legislazione statunitense in materia di contrattazione collettiva sin dall’emanazione del Wagner Act nel 1935. Al riguardo, vengono discusse le regole per il riconoscimento dei sindacati nei luoghi di lavoro e per la stipula degli accordi collettivi (principio di maggioranza e rappresentanza esclusiva, obbligo di negoziare secondo buona fede) e per la gestione del conflitto industriale (arbitrato e clausola di tregua): sulla scorta di un approccio storico-critico e dei leading case giurisprudenzialil’articolosottolineailcarattereprettamenteaziendaleeprivatisticodellere…

Strict quasi-concavity and the differential barrier property of gauges in linear programming

2014

Concave gauge functions were introduced to give an analytical representation of cones. In particular, they give a simple and a practical representation of the positive orthant. There is a wide choice of concave gauge functions with interesting properties, representing the same cone. Besides the fact that a concave gauge cannot be identically zero on a cone(), it may be continuous, differentiable and even on its interior. The purpose of the present paper is to present another approach to penalizing the positivity constraints of a linear programme using an arbitrary strictly quasi-concave gauge representation. Throughout the paper, we generalize the concept of the central path and the analyti…

Locally Convex Quasi *-Algebras of Operators

2011

This note is mainly concerned with locally convex quasi C*-normed *-algebras which arise as completions of C*-algebras of operators under certain topologies. Their importance is made clear by the representation theory of abstract locally convex quasi C*-normed *-algebras, investigated in previous papers and whose basic aspects are also overviewed here.