7,434 research outputs found
Strong Bounds on Sum of Neutrino Masses in a 12 Parameter Extended Scenario with Non-Phantom Dynamical Dark Energy ()
We obtained constraints on a 12 parameter extended cosmological scenario
including non-phantom dynamical dark energy (NPDDE) with CPL parametrization.
We also include the six CDM parameters, number of relativistic
neutrino species () and sum over active neutrino masses
(), tensor-to-scalar ratio (), and running of the
spectral index (). We use CMB Data from Planck 2015; BAO Measurements
from SDSS BOSS DR12, MGS, and 6dFS; SNe Ia Luminosity Distance measurements
from the Pantheon Sample; CMB B-mode polarization data from BICEP2/Keck
collaboration (BK14); Planck lensing data; and a prior on Hubble constant
( km/sec/Mpc) from local measurements (HST). We have found strong
bounds on the sum of the active neutrino masses. For instance, a strong bound
of 0.123 eV (95\% C.L.) comes from Planck+BK14+BAO. Although
we are in such an extended parameter space, this bound is stronger than a bound
of 0.158 eV (95\% C.L.) obtained in with Planck+BAO. Varying instead of
however leads to weaker bounds on . Inclusion of the HST leads to
the standard value of being discarded at more than
68\% C.L., which increases to 95\% C.L. when we vary
instead of , implying a small preference for dark radiation, driven
by the tension.Comment: 23 pages, 10 figures, matches the published versio
Secret Sharing and Proactive Renewal of Shares in Hierarchical Groups
Secret sharing in user hierarchy represents a challenging area for research.
Although a lot of work has already been done in this direc- tion, this paper
presents a novel approach to share a secret among a hierarchy of users while
overcoming the limitations of the already exist- ing mechanisms. Our work is
based on traditional (k +1; n)-threshold secret sharing, which is secure as
long as an adversary can compromise not more than k secret shares. But in real
life it is often feasible for an adversary to obtain more than k shares over a
long period of time. So, in our work we also present a way to overcome this
vulnerability, while implementing our hierarchical secret sharing scheme. The
use of Elliptic Curve Cryptography makes the computations easier and faster in
our work.Comment: 20 Page
A Survey of Cellular Automata: Types, Dynamics, Non-uniformity and Applications
Cellular automata (CAs) are dynamical systems which exhibit complex global
behavior from simple local interaction and computation. Since the inception of
cellular automaton (CA) by von Neumann in 1950s, it has attracted the attention
of several researchers over various backgrounds and fields for modelling
different physical, natural as well as real-life phenomena. Classically, CAs
are uniform. However, non-uniformity has also been introduced in update
pattern, lattice structure, neighborhood dependency and local rule. In this
survey, we tour to the various types of CAs introduced till date, the different
characterization tools, the global behaviors of CAs, like universality,
reversibility, dynamics etc. Special attention is given to non-uniformity in
CAs and especially to non-uniform elementary CAs, which have been very useful
in solving several real-life problems.Comment: 43 pages; Under review in Natural Computin
Using supertags as source language context in SMT
Recent research has shown that Phrase-Based Statistical Machine Translation (PB-SMT) systems can benefit from two
enhancements: (i) using words and POS tags as context-informed features on the source side; and (ii) incorporating lexical syntactic descriptions in the form of supertags on the target side. In this work we
present a novel PB-SMT model that combines these two aspects by using supertags as source language contextinformed features. These features enable us to exploit source similarity in addition to target similarity, as modelled by the language model. In our experiments two
kinds of supertags are employed: those from Lexicalized Tree-Adjoining Grammar and Combinatory Categorial Grammar.
We use a memory-based classification framework that enables the estimation of these features while avoiding
problems of sparseness. Despite the differences between these two approaches, the supertaggers give similar improvements. We evaluate the performance of our approach on an English-to-Chinese translation task using a state-of-the-art phrase-based SMT system, and report an
improvement of 7.88% BLEU score in translation quality when adding supertags as context-informed features
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