941,545 research outputs found
Cosmology seeking friendship with sterile neutrinos
Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation
in the universe beyond photons and ordinary neutrinos, lending support to the
existence of low-mass sterile neutrinos. We use the WMAP 7-year data,
small-scale CMB observations from ACBAR, BICEP and QuAD, the SDSS 7th data
release, and measurement of the Hubble parameter from HST observations to
derive credible regions for the assumed common mass scale m_s and effective
number N_s of thermally excited sterile neutrino states. Our results are
compatible with the existence of one or perhaps two sterile neutrinos, as
suggested by LSND and MiniBooNE, if m_s is in the sub-eV range.Comment: 4 pages, 1 figure, matches version published in PR
Petuum: A New Platform for Distributed Machine Learning on Big Data
What is a systematic way to efficiently apply a wide spectrum of advanced ML
programs to industrial scale problems, using Big Models (up to 100s of billions
of parameters) on Big Data (up to terabytes or petabytes)? Modern
parallelization strategies employ fine-grained operations and scheduling beyond
the classic bulk-synchronous processing paradigm popularized by MapReduce, or
even specialized graph-based execution that relies on graph representations of
ML programs. The variety of approaches tends to pull systems and algorithms
design in different directions, and it remains difficult to find a universal
platform applicable to a wide range of ML programs at scale. We propose a
general-purpose framework that systematically addresses data- and
model-parallel challenges in large-scale ML, by observing that many ML programs
are fundamentally optimization-centric and admit error-tolerant,
iterative-convergent algorithmic solutions. This presents unique opportunities
for an integrative system design, such as bounded-error network synchronization
and dynamic scheduling based on ML program structure. We demonstrate the
efficacy of these system designs versus well-known implementations of modern ML
algorithms, allowing ML programs to run in much less time and at considerably
larger model sizes, even on modestly-sized compute clusters.Comment: 15 pages, 10 figures, final version in KDD 2015 under the same titl
Performance Characterization of In-Memory Data Analytics on a Modern Cloud Server
In last decade, data analytics have rapidly progressed from traditional
disk-based processing to modern in-memory processing. However, little effort
has been devoted at enhancing performance at micro-architecture level. This
paper characterizes the performance of in-memory data analytics using Apache
Spark framework. We use a single node NUMA machine and identify the bottlenecks
hampering the scalability of workloads. We also quantify the inefficiencies at
micro-architecture level for various data analysis workloads. Through empirical
evaluation, we show that spark workloads do not scale linearly beyond twelve
threads, due to work time inflation and thread level load imbalance. Further,
at the micro-architecture level, we observe memory bound latency to be the
major cause of work time inflation.Comment: Accepted to The 5th IEEE International Conference on Big Data and
Cloud Computing (BDCloud 2015
Lenticular galaxies with UV-rings
By using the public UV imaging data obtained by the GALEX (Galaxy Ultraviolet
Explorer) for nearby galaxies, we have compiled a list of lenticular galaxies
possessing ultraviolet rings - starforming regions tightly confined to
particular radial distances from galactic centers. We have studied large-scale
structure of these galaxies in the optical bands by using the data of the SDSS
(Sloan Digital Sky Survey): we have decomposed the galactic images into
large-scale disks and bulges, have measured the ring optical colours from the
residual images after subtracting model disks and bulges, and have compared the
sizes of the rings in the optical light and in the UV-band. The probable origin
of the outer starforming ring appearances in unbarred galaxies demonstrating
otherwise the regular structure and homogeneously old stellar population beyond
the rings is discussed.Comment: 9 pages plus one big colour figure in the Appendix; the slightly
expanded version of the paper accepted to Astronomy Letter
Proliferating Cloud Density through Big Data Ecosystem, Novel XCLOUDX Classification and Emergence of as-a-Service Era
Big Data is permeating through the bigger aspect of human life for scientific and commercial dependencies, especially for massive scale data analytics of beyond the exabyte magnitude. As the footprint of Big Data applications is continuously expanding, the reliability on cloud environments is also increasing to obtain appropriate, robust and affordable services to deal with Big Data challenges. Cloud computing avoids any need to locally maintain the overly scaled computing infrastructure that include not only dedicated space, but the expensive hardware and software also. Several data models to process Big Data are already developed and a number of such models are still emerging, potentially relying on heterogeneous underlying storage technologies, including cloud computing. In this paper, we investigate the growing role of cloud computing in Big Data ecosystem. Also, we propose a novel XCLOUDX {XCloudX, X…X} classification to zoom in to gauge the intuitiveness of the scientific name of the cloud-assisted NoSQL Big Data models and analyze whether XCloudX always uses cloud computing underneath or vice versa. XCloudX symbolizes those NoSQL Big Data models that embody the term “cloud” in their name, where X is any alphanumeric variable. The discussion is strengthen by a set of important case studies. Furthermore, we study the emergence of as-a-Service era, motivated by cloud computing drive and explore the new members beyond traditional cloud computing stack, developed over the last few years
Humor styles and the ten personality dimensions from the Supernumerary Personality Inventory
BACKGROUND The present study examines the relationship between humor styles and the 10 Supernumerary Personality Inventory (SPI) traits to understand how humor styles correlate with personality dimensions “beyond the Big Five” model. Humor styles and the personality dimensions of the SPI have yet to be explored. Therefore, the aim of this study is to explore how humor styles correlate with traits outside of conventional personality models, in order to better understand humor expression related to personality traits. PARTICIPANTS AND PROCEDURE The data were from 693 adult participants (135 men and 560 women) from North America. RESULTS All four humor styles positively correlated with the SPI humorousness scale. The two positive humor styles, affiliative and self-enhancing, had significant positive correlations with the egotism SPI scale. The two negative humor styles, aggressive and self-defeating, had significant positive correlations with the SPI scales of seductiveness and manipulativeness and significant negative correlations with the integrity scale from the SPI. A sub-group of the sample (n = 471) also completed a Big Five personality measure. For this sample, the variance due to the Big Five was regressed out of the SPI scales. CONCLUSIONS The correlations between the SPI residuals and the humor style scores decreased from the unaltered SPI scale scores except for the aggressive humor style correlations, which were less affected, suggesting that this dimension of humor may have some variance “beyond” the Big Five
- …