30,650 research outputs found
Short-Term Load Forecasting: The Similar Shape Functional Time Series Predictor
We introduce a novel functional time series methodology for short-term load
forecasting. The prediction is performed by means of a weighted average of past
daily load segments, the shape of which is similar to the expected shape of the
load segment to be predicted. The past load segments are identified from the
available history of the observed load segments by means of their closeness to
a so-called reference load segment, the later being selected in a manner that
captures the expected qualitative and quantitative characteristics of the load
segment to be predicted. Weak consistency of the suggested functional similar
shape predictor is established. As an illustration, we apply the suggested
functional time series forecasting methodology to historical daily load data in
Cyprus and compare its performance to that of a recently proposed alternative
functional time series methodology for short-term load forecasting.Comment: 22 pages, 6 Figures, 1 Tabl
Transverse effects in multifrequency Raman generation
The theory of ultrabroadband multifrequency Raman generation is extended, for the first time, to allow for beam-propagation effects in one and two transverse dimensions. We show that a complex transverse structure develops even when diffraction is neglected. In the general case, we examine how the ultrabroadband multifrequency Raman generation process is affected by the intensity, phase quality, and width of the input beams, and by the length of the Raman medium. The evolution of power spectra, intensity profiles, and global characteristics of the multifrequency beams are investigated and explained. In the two-dimensional transverse case, bandwidths comparable to the optical carrier frequency, spanning the whole visible spectrum and beyond, are still achievable
BNP-Seq: Bayesian Nonparametric Differential Expression Analysis of Sequencing Count Data
We perform differential expression analysis of high-throughput sequencing
count data under a Bayesian nonparametric framework, removing sophisticated
ad-hoc pre-processing steps commonly required in existing algorithms. We
propose to use the gamma (beta) negative binomial process, which takes into
account different sequencing depths using sample-specific negative binomial
probability (dispersion) parameters, to detect differentially expressed genes
by comparing the posterior distributions of gene-specific negative binomial
dispersion (probability) parameters. These model parameters are inferred by
borrowing statistical strength across both the genes and samples. Extensive
experiments on both simulated and real-world RNA sequencing count data show
that the proposed differential expression analysis algorithms clearly
outperform previously proposed ones in terms of the areas under both the
receiver operating characteristic and precision-recall curves.Comment: To appear in Journal of the American Statistical Associatio
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