20,029 research outputs found

    Bulk and boundary g2g_2 factorized S-matrices

    Full text link
    We investigate the g2g_2-invariant bulk (1+1D, factorized) SS-matrix constructed by Ogievetsky, using the bootstrap on the three-point coupling of the vector multiplet to constrain its CDD ambiguity. We then construct the corresponding boundary SS-matrix, demonstrating it to be consistent with Y(g2,a1Ă—a1)Y(g_2,a_1\times a_1) symmetry.Comment: 7 page

    A practical Bayesian framework for backpropagation networks

    Get PDF
    A quantitative and practical Bayesian framework is described for learning of mappings in feedforward networks. The framework makes possible (1) objective comparisons between solutions using alternative network architectures, (2) objective stopping rules for network pruning or growing procedures, (3) objective choice of magnitude and type of weight decay terms or additive regularizers (for penalizing large weights, etc.), (4) a measure of the effective number of well-determined parameters in a model, (5) quantified estimates of the error bars on network parameters and on network output, and (6) objective comparisons with alternative learning and interpolation models such as splines and radial basis functions. The Bayesian "evidence" automatically embodies "Occam's razor," penalizing overflexible and overcomplex models. The Bayesian approach helps detect poor underlying assumptions in learning models. For learning models well matched to a problem, a good correlation between generalization ability and the Bayesian evidence is obtained

    Bayesian interpolation

    Get PDF
    Although Bayesian analysis has been in use since Laplace, the Bayesian method of model-comparison has only recently been developed in depth. In this paper, the Bayesian approach to regularization and model-comparison is demonstrated by studying the inference problem of interpolating noisy data. The concepts and methods described are quite general and can be applied to many other data modeling problems. Regularizing constants are set by examining their posterior probability distribution. Alternative regularizers (priors) and alternative basis sets are objectively compared by evaluating the evidence for them. “Occam's razor” is automatically embodied by this process. The way in which Bayes infers the values of regularizing constants and noise levels has an elegant interpretation in terms of the effective number of parameters determined by the data set. This framework is due to Gull and Skilling

    Information-based objective functions for active data selection

    Get PDF
    Learning can be made more efficient if we can actively select particularly salient data points. Within a Bayesian learning framework, objective functions are discussed that measure the expected informativeness of candidate measurements. Three alternative specifications of what we want to gain information about lead to three different criteria for data selection. All these criteria depend on the assumption that the hypothesis space is correct, which may prove to be their main weakness

    Exploring Culturally Responsive Teaching and Student-Created Videos in an At-Risk Middle School Classroom

    Get PDF
    As the United States public school classrooms encounter notable shifts in student demographics and increased access to technology, teachers face the dual challenges of cultural and digital differences as they attempt to build relationships with students and develop responsive and relevant instruction. Framed by culturally responsive teaching, this qualitative study explored how one middle school teacher and his students in two summer school English classes interacted with and responded to novel technology-based instructional approach that sought to connect the students’ lives outside of school to the classroom. The findings suggest that involving the students within this culturally responsive teaching approach using student-created videos informs the contribution of both the teacher and the students for connecting home and school contexts with a CRT framework
    • …
    corecore