Common transversals

AbstractGiven t families, each family consisting of s finite sets, we show that if the families “separate points” in a natural way, and if the union of all the sets in all the families contains more than (s + 1)t − st−1 − 1 elements, then a common transversal of the t families exists. In case each family is a covering family, the bound is st − st−1. Both of these bounds are best possible. This work extends recent work of Longyear [2]

“Am I No Longer Gifted?”: Imagining a More Capacious World for Black Girls in Alternative Education

Advancing the discourse on the experiences of historically marginalized students in alternative learning settings, this track delves into the intricate terrain through which Black girls in alternative education navigate their high-ability and gifted educational journeys within these distinctive learning environments. In this sphere, we advance the evolution of innovative theoretical and pedagogical paradigms in alternative education, transcending conventional boundaries and drawing from the diverse lived experiences of Black girls. In this regard, the conceptualization of the Black Girl Educology (BGE) framework embodies this ethos, fostering an environment conducive to inquiry and exploration of essential variables in alternative education. Our BGE framework prioritizes the ways of knowing and doing that empower Black girls to occupy a central role within established systems of learning. As previous scholars have uncovered how underrepresented students manifest their talents, a recurring theme emerges: their potential often remains concealed due to preconceived notions regarding perceived negative behaviors, aptitudes, and traits. BGE prompts the essentiality of scholarly explorations that have predominantly focused on traditional educational settings, neglecting the unique context of alternative education. The primary objective of this track is to elucidate the status of Black girls within alternative education and to leverage the strengths in BGE as a tool to delineate the pathways through which high-ability and gifted students navigate their journey into and through these distinctive learning environments. By shedding light on the experiences of these students, we aim to foster an environment that recognizes their talents and unlocks their full potential

New Way to Produce Dense Double-Antikaonic Dibaryon System, \bar{K}\bar{K} NN, through Lambda(1405)-Doorway Sticking in p+p Collisions

A recent successful observation of a dense and deeply bound \bar{K} nuclear system, K^-pp, in the p + p \rightarrow K^+ + K^-pp reaction in a DISTO experiment indicates that the double-\bar{K} dibaryon, K^-K^-pp, which was predicted to be a dense nuclear system, can also be formed in p+p collisions. We find theoretically that the K^- -K^- repulsion plays no significant role in reducing the density and binding energy of K^-K^-pp and that, when two \Lambda(1405) resonances are produced simultaneously in a short-range p+p collision, they act as doorways to copious formation of K^-K^-pp, if and only if K^-K^-pp is a dense object, as predicted.Comment: 8 pages, 9 figures, Accepted Apr. 19, 201

On the stability of Dirac sheet configurations

Using cooling for SU(2) lattice configurations, purely Abelian constant magnetic field configurations were left over after the annihilation of constituents that formed metastable Q=0 configurations. These so-called Dirac sheet configurations were found to be stable if emerging from the confined phase, close to the deconfinement phase transition, provided their Polyakov loop was sufficiently non-trivial. Here we show how this is related to the notion of marginal stability of the appropriate constant magnetic field configurations. We find a perfect agreement between the analytic prediction for the dependence of stability on the value of the Polyakov loop (the holonomy) in a finite volume and the numerical results studied on a finite lattice in the context of the Dirac sheet configurations

Spin polarization and magneto-luminescence of confined electron-hole systems

A BCS-like variational wave-function, which is exact in the infinite field limit, is used to study the interplay among Zeeman energies, lateral confinement and particle correlations induced by the Coulomb interactions in strongly pumped neutral quantum dots. Band mixing effects are partially incorporated by means of field-dependent masses and g-factors. The spin polarization and the magneto-luminescence are computed as functions of the number of electron-hole pairs present in the dot and the applied magnetic field.Comment: To appear in Phys. Rev.

Status of Vectorized Monte Carlo for Particle Transport Analysis

The conventional particle transport Monte Carlo algorithm is ill suited for modem vector supercomputers because the random nature of the particle transport process in the history based algorithm in hibits construction of vectors. An alterna tive, event-based algorithm is suitable for vectorization and has been used recently to achieve impressive gains in perfor mance on vector supercomputers. This re view describes the event-based algorithm and several variations of it Implementa tions of this algorithm for applications in particle transport are described, and their relative merits are discussed. The imple mentation of Monte Carlo methods on multiple vector parallel processors is con sidered, as is the potential of massively parallel processors for Monte Carlo par ticle transport simulations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67177/2/10.1177_109434208700100203.pd

Kinematically Complete Measurements of p+p → p+n+(pi+) Near Threshold

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Metacognition and lifelong e-learning: a contextual and cyclical process

Metacognition is arguably an important conceptualisation within the area of lifelong e- learning, with many theorists and practitioners claiming that it enhances the learning process. However, the lifelong, cyclical and flexible aspects of 'before', 'during' and 'after' metacognitions within lifelong e-learning (inclusive of whether an 'input' necessarily leads to a completed 'output') seem marginal within current areas of practical and theoretical debate. This article analyses Reeves's (1997) model of web-based learning in the context of the ADAPT project; a study of lifelong learners based in small and medium sized enterprises. The article focuses upon an analysis of this model's view of metacognition, and in the light of the project findings and literature review, aims to put forward an extended and expanded version of the model with reference to lifelong e-learnin

Multifractal Analysis of inhomogeneous Bernoulli products

We are interested to the multifractal analysis of inhomogeneous Bernoulli products which are also known as coin tossing measures. We give conditions ensuring the validity of the multifractal formalism for such measures. On another hand, we show that these measures can have a dense set of phase transitions