4,573 research outputs found

    On a generalization of the Jensen-Shannon divergence and the JS-symmetrization of distances relying on abstract means

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    The Jensen-Shannon divergence is a renown bounded symmetrization of the unbounded Kullback-Leibler divergence which measures the total Kullback-Leibler divergence to the average mixture distribution. However the Jensen-Shannon divergence between Gaussian distributions is not available in closed-form. To bypass this problem, we present a generalization of the Jensen-Shannon (JS) divergence using abstract means which yields closed-form expressions when the mean is chosen according to the parametric family of distributions. More generally, we define the JS-symmetrizations of any distance using generalized statistical mixtures derived from abstract means. In particular, we first show that the geometric mean is well-suited for exponential families, and report two closed-form formula for (i) the geometric Jensen-Shannon divergence between probability densities of the same exponential family, and (ii) the geometric JS-symmetrization of the reverse Kullback-Leibler divergence. As a second illustrating example, we show that the harmonic mean is well-suited for the scale Cauchy distributions, and report a closed-form formula for the harmonic Jensen-Shannon divergence between scale Cauchy distributions. We also define generalized Jensen-Shannon divergences between matrices (e.g., quantum Jensen-Shannon divergences) and consider clustering with respect to these novel Jensen-Shannon divergences.Comment: 33 page

    Learning With Jensen-Tsallis Kernels

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    Jensen-type Jensen-Shannon (JS) and Jensen-Tsallis] kernels were first proposed by Martins et al. (2009). These kernels are based on JS divergences that originated in the information theory. In this paper, we extend the Jensen-type kernels on probability measures to define positive-definite kernels on Euclidean space. We show that the special cases of these kernels include dot-product kernels. Since Jensen-type divergences are multidistribution divergences, we propose their multipoint variants, and study spectral clustering and kernel methods based on these. We also provide experimental studies on benchmark image database and gene expression database that show the benefits of the proposed kernels compared with the existing kernels. The experiments on clustering also demonstrate the use of constructing multipoint similarities

    On the Jensen–Shannon Symmetrization of Distances Relying on Abstract Means

    No full text
    The Jensen–Shannon divergence is a renowned bounded symmetrization of the unbounded Kullback–Leibler divergence which measures the total Kullback–Leibler divergence to the average mixture distribution. However, the Jensen–Shannon divergence between Gaussian distributions is not available in closed form. To bypass this problem, we present a generalization of the Jensen–Shannon (JS) divergence using abstract means which yields closed-form expressions when the mean is chosen according to the parametric family of distributions. More generally, we define the JS-symmetrizations of any distance using parameter mixtures derived from abstract means. In particular, we first show that the geometric mean is well-suited for exponential families, and report two closed-form formula for (i) the geometric Jensen–Shannon divergence between probability densities of the same exponential family; and (ii) the geometric JS-symmetrization of the reverse Kullback–Leibler divergence between probability densities of the same exponential family. As a second illustrating example, we show that the harmonic mean is well-suited for the scale Cauchy distributions, and report a closed-form formula for the harmonic Jensen–Shannon divergence between scale Cauchy distributions. Applications to clustering with respect to these novel Jensen–Shannon divergences are touched upon

    Jensen-Shannon divergence and cosine follow a similar pattern to the perplexity.

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    JS increases from 10 (higher is better) and cosine decreases from 10 (lower is better). (TIF)</p

    Chosen logistics processes in Škoda JS

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    This master thesis deals with the purchase and sale process in Škoda JS company. The aim of this work is to assess whether the setting of the purchase and sale process is met by the company also within a real business case, in compliance with set controls, and whether the degree of perfect delivery is sufficient. In the introduction, the author specifies the basic terms: logistics, logistic chain, customer benefits, information systems in logistics, buying and selling. The following chapter introduces Škoda JS company, including the sphere of its entrepreneurial activity. This chapter also deals with the nuclear power industry. In the crucial chapter, the author describes the process of purchase and sale in Škoda JS company and compares it with a real business case. In conclusion, the author evaluates discrepancies and suggests recommendations to avoid them

    Conceptualizing Surprise with the Jensen–Shannon distance: A Bayesian Information Theoretical Approach for the Social Sciences

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    Generally in the social sciences, a result is informally deemed ‘surprising’ if its associated p-value is sufficiently small. This implicit interpretation, however, is both conceptually and mathematically inappropriate, and such misuse of the p-value can lead to erroneous conclusions about the novelty of results. To solve that issue, this paper builds on Bayesian inference, Information theory, and considerations specific to the social sciences, to argue for the adoption of a more appropriate conceptualization of surprise as the relative entropy between prior and posterior knowledge. Novel to the social sciences, this formal conceptualization enables researchers to appropriately measure surprise as the Jensen-Shannon distance, for which the paper contributes with easily implementable software and a demonstration of its use in relation to empirical data.© Keywords: Surprise; Novelty; Jensen-Shannon distance; JS distance; Jensen-Shannon divergence; JS divergence; Relative entropy; Kullback-Leibler divergence; KL divergence; Distance; Divergence; Dissimilarity; Differential entropy; Entropy; p-value; S-value; Information theory; Bayesian inferenc
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