5,329 research outputs found
Particle Gibbs for Bayesian Additive Regression Trees
Additive regression trees are flexible non-parametric models and popular
off-the-shelf tools for real-world non-linear regression. In application
domains, such as bioinformatics, where there is also demand for probabilistic
predictions with measures of uncertainty, the Bayesian additive regression
trees (BART) model, introduced by Chipman et al. (2010), is increasingly
popular. As data sets have grown in size, however, the standard
Metropolis-Hastings algorithms used to perform inference in BART are proving
inadequate. In particular, these Markov chains make local changes to the trees
and suffer from slow mixing when the data are high-dimensional or the best
fitting trees are more than a few layers deep. We present a novel sampler for
BART based on the Particle Gibbs (PG) algorithm (Andrieu et al., 2010) and a
top-down particle filtering algorithm for Bayesian decision trees
(Lakshminarayanan et al., 2013). Rather than making local changes to individual
trees, the PG sampler proposes a complete tree to fit the residual. Experiments
show that the PG sampler outperforms existing samplers in many settings
Mondrian Forests for Large-Scale Regression when Uncertainty Matters
Many real-world regression problems demand a measure of the uncertainty
associated with each prediction. Standard decision forests deliver efficient
state-of-the-art predictive performance, but high-quality uncertainty estimates
are lacking. Gaussian processes (GPs) deliver uncertainty estimates, but
scaling GPs to large-scale data sets comes at the cost of approximating the
uncertainty estimates. We extend Mondrian forests, first proposed by
Lakshminarayanan et al. (2014) for classification problems, to the large-scale
non-parametric regression setting. Using a novel hierarchical Gaussian prior
that dovetails with the Mondrian forest framework, we obtain principled
uncertainty estimates, while still retaining the computational advantages of
decision forests. Through a combination of illustrative examples, real-world
large-scale datasets, and Bayesian optimization benchmarks, we demonstrate that
Mondrian forests outperform approximate GPs on large-scale regression tasks and
deliver better-calibrated uncertainty assessments than decision-forest-based
methods.Comment: Proceedings of the 19th International Conference on Artificial
Intelligence and Statistics (AISTATS) 2016, Cadiz, Spain. JMLR: W&CP volume
5
Counting the Invisible Working Hands in India
This paper enquires into the problem faced by migrant labors in the informal sector in India It argues for the registration and tracking of migrants particularly interstate migrants as they constitute a significant proportion of the labour force The mobility of labor is the natural mechanism for infusing inclusive and faster growth across the globe and tracking the poor migrants would lead to investment in human and social capital paving the way for integrating poverty alleviation policies and development strategies for overall better outcome
A HISTORICAL APPROACH FOR UNDERSTANDING AYURVEDA
Ayurveda is the traditional system of Indian medicine and being historical, linguistic, religious, philosophical importance of Ayurveda, it is very necessary to do critical study of Ayurveda according to ancient Indias history, Prakrita, Pali (Magdhi), Ardhamagdhi languages, religious and philosophical point of view. It is prejudice to compare Ayurveda with the modern science. First, we should try to know what is Ayurveda? It is considered as science of life but what is the meaning of science according to Indian philosophy? Ayurveda is considered as the philosophy as well as clinical science also. The two main distinctions of Indian philosophy – the believer (i.e. Sankhya, Yog, Nyaya, Vaisheshika, Purva Mimansa, Uttar Mimansa) and the atheist (i.e. Charvaka, Jain and Baudha) philosophy. Unless and until we have the deep knowledge of Indian philosophical sciences i.e. Darshan Shastras (Aastika and Naastika), we wont be able to understand Ayurveda properly. Therefore, it is the need of time to do critical study of Darshan Shastras (Aastika and Naastika) and it is to be noted that with the help of Sanskrita language alone we wont be able to achieve our goal; it is very much important to have the knowledge of languages such as Prakrit, Pali which is also known as Magadhi and Ardhamagdhi, then only we could be able to understand the proper meanings of Darshan Shastras (Aastika and Naastika); Buddhist literature is available in the Pali language which is also known as Magdhi; it was the dialect of ancient north India, and Ardhamagdhi is the language in which Jain literature is available. This research paper is an attempt to review the Ayurveda literature regarding historical facts and what are the means so that we could able to understand Ayurveda appropriately.
Radiative stability of neutrino-mass textures
Neutrino-mass textures proposed at high-scales are known to be unstable
against radiative corrections especially for nearly degenerate eigen values.
Within the renormalization group constraints we find a mechanism in a class of
gauge theories which guarantees reproduction of any high-scale texture at low
energies with radiative stability. We also show how the mechanism explains
solar and atmospheric neutrino anomalies through the bimaximal texture at high
scale.Comment: 4 pages REVTEX, 1 Postscript fi
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