1,321 research outputs found
Study of resonance light scattering for remote optical probing
Enhanced scattering and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between scattering and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted light following excitation of pulsed incident light. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance scattering. New results are obtained for depolarization of scattering excited by light at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible light. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed light with 5 nsec pulse duration and 0.005 nm spectral width
Cluster derivation of Parisi's RSB solution for disordered systems
We propose a general scheme in which disordered systems are allowed to
sacrifice energy equi-partitioning and separate into a hierarchy of ergodic
sub-systems (clusters) with different characteristic time-scales and
temperatures. The details of the break-up follow from the requirement of
stationarity of the entropy of the slower cluster, at every level in the
hierarchy. We apply our ideas to the Sherrington-Kirkpatrick model, and show
how the Parisi solution can be {\it derived} quantitatively from plausible
physical principles. Our approach gives new insight into the physics behind
Parisi's solution and its relations with other theories, numerical experiments,
and short range models.Comment: 7 pages 5 figure
Hierarchical Self-Programming in Recurrent Neural Networks
We study self-programming in recurrent neural networks where both neurons
(the `processors') and synaptic interactions (`the programme') evolve in time
simultaneously, according to specific coupled stochastic equations. The
interactions are divided into a hierarchy of groups with adiabatically
separated and monotonically increasing time-scales, representing sub-routines
of the system programme of decreasing volatility. We solve this model in
equilibrium, assuming ergodicity at every level, and find as our
replica-symmetric solution a formalism with a structure similar but not
identical to Parisi's -step replica symmetry breaking scheme. Apart from
differences in details of the equations (due to the fact that here
interactions, rather than spins, are grouped into clusters with different
time-scales), in the present model the block sizes of the emerging
ultrametric solution are not restricted to the interval , but are
independent control parameters, defined in terms of the noise strengths of the
various levels in the hierarchy, which can take any value in [0,\infty\ket.
This is shown to lead to extremely rich phase diagrams, with an abundance of
first-order transitions especially when the level of stochasticity in the
interaction dynamics is chosen to be low.Comment: 53 pages, 19 figures. Submitted to J. Phys.
The XY Spin-Glass with Slow Dynamic Couplings
We investigate an XY spin-glass model in which both spins and couplings
evolve in time: the spins change rapidly according to Glauber-type rules,
whereas the couplings evolve slowly with a dynamics involving spin correlations
and Gaussian disorder. For large times the model can be solved using replica
theory. In contrast to the XY-model with static disordered couplings, solving
the present model requires two levels of replicas, one for the spins and one
for the couplings. Relevant order parameters are defined and a phase diagram is
obtained upon making the replica-symmetric Ansatz. The system exhibits two
different spin-glass phases, with distinct de Almeida-Thouless lines, marking
continuous replica-symmetry breaking: one describing freezing of the spins
only, and one describing freezing of both spins and couplings.Comment: 7 pages, Latex, 3 eps figure
Um caso para competências: avaliar o valor do traço-baseado: Avaliação de desempenho para os funcionários não-faculdade da Universidade
A case study analyzed how supervisors at one university selected competencies, or trait-based skills, for non-faculty employees. This case study provides a valuable contribution by focusing on employees at one institution type–a large, public research university. While it has been documented that non-faculty employees provide important contributions to higher education, there is more to be discovered about this population of university employee, noted as more than 2 million U.S. employees in 2011. The research question guiding this study was: Within a university setting, how are employee competencies valued by job title within colleges and divisions? Multiple correspondence analysis evaluated supervisor competency selection for 1,836 non-supervisory and 565 supervisory employees using data from this university’s 2012 performance appraisal. For non-supervisory employees, the first dimension accounted for 65.11% of adjusted inertia, or explained variance. The second dimension accounted for 23.89% of adjusted inertia. For supervisory employees, the first dimension accounted for 86.57% of adjusted inertia. The second dimension accounted for 8.26% of adjusted inertia. The key study finding was that, despite the availability of other higher-education specific competency alternatives and best practices for competency use in the appraisal, this institution’s implementation of competencies was found to be mechanical. This study proposed best practices for this and similarly situated institutions as to how competencies can be used to develop employees and improve their performance.Un estudio de caso analizado cómo supervisores en una Universidad seleccionan las competencias o habilidades basadas en el rasgo, no Facultad empleados. Este estudio de caso proporciona una valiosa contribución al centrarse en los empleados en un tipo de institución, una Universidad de investigación grande, público. Mientras que se ha documentado que no Facultad empleados brindan importantes aportes a la educación superior, hay más por descubrir acerca de esta población de empleados de la Universidad, señaló como empleados de los Estados Unidos más de 2 millones en 2011. ¿Fue la pregunta de investigación que guía este estudio: dentro de un ámbito universitario, cómo son las competencias del empleado valoradas por título del trabajo en universidades y divisiones? Análisis de correspondencia múltiple había evaluado supervisor competencias selección de 1.836 no supervisión y 565 empleados supervisión utilizando los datos de evaluación del desempeño de la Universidad 2012. Empleados sin supervisión, la primera dimensión representaron el 65.11% de inercia ajustada o explicó la varianza. La segunda dimensión 23.89% de inercia ajustada. Para los empleados de supervisión, la primera dimensión representaron 86.57% de inercia ajustada. La segunda dimensión 8.26% de inercia ajustada. El hallazgo clave del estudio fue a pesar de la disponibilidad de otras alternativas de la competencia específica de la educación superior y las mejores prácticas para el uso de competencias en la evaluación, implementación de esta institución de competencias fue encontrado para ser mecánico. Este estudio propone instituciones situación similar en cuanto a cómo las competencias se pueden utilizar para desarrollar a empleados y mejorar su desempeño y mejores prácticas para esto.Um estudo de caso analisado como supervisores numa Universidade selecionado competências ou habilidades baseadas em traço, para os empregados não-docente. Este estudo de caso fornece uma contribuição valiosa, centrando-se sobre os funcionários em um tipo de instituição – uma grande, pública, Universidade. Embora tem sido documentado que os funcionários não-faculdade fornecem importantes contribuições para o ensino superior, há mais a ser descoberto sobre esta população de funcionários da Universidade, observou-se como funcionários de Estados Unidos mais de 2 milhões em 2011. A pergunta de pesquisa orientar este estudo foi: dentro de um cenário de Universidade, como são competências do empregado valorizadas pelo cargo dentro de faculdades e divisões? Análise de correspondência múltipla avaliada seleção de competências de supervisor para 1.836 não-supervisão e 565 funcionários supervisão usando os dados de avaliação de desempenho de 2012 da Universidade. Para empregados não-supervisão, primeira dimensão representou 65.11% da inércia ajustada ou variância, explicou. A segunda dimensão representou 23.89% da inércia ajustada. Para funcionários de fiscalização, a primeira dimensão representou 86.57% de inércia ajustada. A segunda dimensão representaram 8.26% da inércia ajustada. A conclusão do estudo chave era que apesar da disponibilidade de outras alternativas de competência específica de ensino superior e as melhores práticas para uso de competência na avaliação, implementação desta instituição de competências foi encontrada para ser mecânico. Este estudo propõe-se similarmente situadas instituições quanto como competências podem ser usadas para desenvolver os funcionários e melhorar o seu desempenho e melhores práticas para isso
Replica symmetry breaking in an adiabatic spin-glass model of adaptive evolution
We study evolutionary canalization using a spin-glass model with replica
theory, where spins and their interactions are dynamic variables whose
configurations correspond to phenotypes and genotypes, respectively. The spins
are updated under temperature T_S, and the genotypes evolve under temperature
T_J, according to the evolutionary fitness. It is found that adaptation occurs
at T_S < T_S^{RS}, and a replica symmetric phase emerges at T_S^{RSB} < T_S <
T_S^{RS}. The replica symmetric phase implies canalization, and replica
symmetry breaking at lower temperatures indicates loss of robustness.Comment: 5pages, 2 figure
The challenges of intersectionality: Researching difference in physical education
Researching the intersection of class, race, gender, sexuality and disability raises many issues for educational research. Indeed, Maynard (2002, 33) has recently argued that ‘difference is one of the most significant, yet unresolved, issues for feminist and social thinking at the beginning of the twentieth century’. This paper reviews some of the key imperatives of working with ‘intersectional theory’ and explores the extent to these debates are informing research around difference in education and Physical Education (PE). The first part of the paper highlights some key issues in theorising and researching intersectionality before moving on to consider how difference has been addressed within PE. The paper then considers three ongoing challenges of intersectionality – bodies and embodiment, politics and practice and empirical research. The paper argues for a continued focus on the specific context of PE within education for its contribution to these questions
New Singular and Nonsingular Colliding Wave Solutions in Einstein - Maxwell - Scalar Theory
A technique is given to generate coupled scalar field solutions in colliding
Einstein - Maxwell (EM) waves. By employing the Bell - Szekeres solution as
seed and depending on the chosen scalar field it is possible to construct
nonsingular solutions. If the original EM solution is already singular addition
of scalar fields does not make the physics any better. In particular, scalar
field solution that is transformable to spherical symmetry is plagued with
singularities.Comment: 15 pages, To be published in GR
Thinking differently about curriculum:Analysing the potential contribution of physical education as part of 'health and wellbeing' during a time of revised curriculum ambitions in Scotland
Physically fit or physically literate? Children with special educational needs understanding of physical education
The role of physical literacy within physical education (PE) has become a widely debated topic in recent years. Its role in educating children about physicality through embodiment, skill acquisition and reading the environment is argued to be of great benefit to children. However, whether children understand the role of PE in the development of these competencies is not clear, and this is even truer for children who have special educational needs (SEN). Drawing on qualitative phenomenological data from 30 children in key stages 2 and three (7 to 14 years of age) who have SEN, this paper explores notions of physical fitness and physical literacy as understood by children in PE lessons. It aims to gain insight into the ways that children understand the purpose of PE, and places these perceptions within a physical literacy framework, using the National Curriculum for PE (NCPE) as a foundation. Findings demonstrate that children with SEN perceive PE as a means for improving physical fitness, whereas concepts surrounding physical literacy appear to be lost. The paper concludes by making recommendations for factoring physical literacy components more forcibly into the PE curriculum, and through initial teacher training and continued professional development
- …