2,025 research outputs found
Modified SPLICE and its Extension to Non-Stereo Data for Noise Robust Speech Recognition
In this paper, a modification to the training process of the popular SPLICE
algorithm has been proposed for noise robust speech recognition. The
modification is based on feature correlations, and enables this stereo-based
algorithm to improve the performance in all noise conditions, especially in
unseen cases. Further, the modified framework is extended to work for
non-stereo datasets where clean and noisy training utterances, but not stereo
counterparts, are required. Finally, an MLLR-based computationally efficient
run-time noise adaptation method in SPLICE framework has been proposed. The
modified SPLICE shows 8.6% absolute improvement over SPLICE in Test C of
Aurora-2 database, and 2.93% overall. Non-stereo method shows 10.37% and 6.93%
absolute improvements over Aurora-2 and Aurora-4 baseline models respectively.
Run-time adaptation shows 9.89% absolute improvement in modified framework as
compared to SPLICE for Test C, and 4.96% overall w.r.t. standard MLLR
adaptation on HMMs.Comment: Submitted to Automatic Speech Recognition and Understanding (ASRU)
2013 Worksho
Transition from confined to bulk dynamics in symmetric star-linear polymer mixtures
We report on the linear viscoelastic properties of mixtures comprising
multiarm star (as model soft colloids) and long linear chain homopolymers in a
good solvent. In contrast to earlier works, we investigated symmetric mixtures
(with a size ratio of 1) and showed that the polymeric and colloidal responses
can be decoupled. The adopted experimental protocol involved probing the linear
chain dynamics in different star environments. To this end, we studied mixtures
with different star mass fraction, which was kept constant while linear chains
were added and their entanglement plateau modulus () and terminal
relaxation time () were measured as functions of their concentration.
Two distinct scaling regimes were observed for both and : at low
linear polymer concentrations, a weak concentration dependence was observed,
that became even weaker as the fraction of stars in the mixtures increased into
the star glassy regime. On the other hand, at higher linear polymer
concentrations, the classical entangled polymer scaling was recovered. Simple
scaling arguments show that the threshold crossover concentration between the
two regimes corresponds to the maximum osmotic star compression and signals the
transition from confined to bulk dynamics. These results provide the needed
ingredients to complete the state diagram of soft colloid-polymer mixtures and
investigate their dynamics at large polymer-colloid size ratios. They also
offer an alternative way to explore aspects of the colloidal glass transition
and the polymer dynamics in confinement. Finally, they provide a new avenue to
tailor the rheology of soft composites.Comment: 9 Figure
The Library of Babel
We show that heavy pure states of gravity can appear to be mixed states to
almost all probes. Our arguments are made for Schwarzschild black
holes using the field theory dual to string theory in such spacetimes. Our
results follow from applying information theoretic notions to field theory
operators capable of describing very heavy states in gravity. For certain
supersymmetric states of the theory, our account is exact: the microstates are
described in gravity by a spacetime ``foam'', the precise details of which are
invisible to almost all probes.Comment: 7 pages, 1 figure, Essay receiving honorable mention in the 2005
Gravity Research Foundation essay competitio
Mycobiome of the Bat White Nose Syndrome (WNS) Affected Caves and Mines reveals High Diversity of Fungi and Local Adaptation by the Fungal Pathogen Pseudogymnoascus (Geomyces) destructans
The investigations of the bat White Nose Syndrome (WNS) have yet to provide
answers as to how the causative fungus Pseudogymnoascus (Geomyces) destructans
(Pd) first appeared in the Northeast and how a single clone has spread rapidly
in the US and Canada. We aimed to catalogue Pd and all other fungi (mycobiome)
by the culture-dependent (CD) and culture-independent (CI) methods in four
Mines and two Caves from the epicenter of WNS zoonotic. Six hundred sixty-five
fungal isolates were obtained by CD method including the live recovery of Pd.
Seven hundred three nucleotide sequences that met the definition of operational
taxonomic units (OTUs) were recovered by CI methods. Most OTUs belonged to
unidentified clones deposited in the databases as environmental nucleic acid
sequences (ENAS). The core mycobiome of WNS affected sites comprised of 46
species of fungi from 31 genera recovered in culture, and 17 fungal genera and
31 ENAS identified from clone libraries. Fungi such as Arthroderma spp.,
Geomyces spp., Kernia spp., Mortierella spp., Penicillium spp., and
Verticillium spp. were predominant in culture while Ganoderma spp., Geomyces
spp., Mortierella spp., Penicillium spp. and Trichosporon spp. were abundant is
clone libraries. Alpha diversity analyses from CI data revealed that fungal
community structure was highly diverse. However, the true species diversity
remains undetermined due to under sampling. The frequent recovery of Pd
indicated that the pathogen has adapted to WNS-afflicted habitats. Further,
this study supports the hypothesis that Pd is an introduced species. These
findings underscore the need for integrated WNS control measures that target
both bats and the fungal pathogen.Comment: 59 pages, 7figure
New large volume Calabi-Yau threefolds
In previous work, we have commenced the task of unpacking the 473 800 776 reflexive polyhedra by Kreuzer and Skarke into a database of Calabi-Yau threefolds [R. Altman et al. J. High Energy Phys. 02 (2015) 158.] (see www.rossealtman.com). In this paper, following a pedagogical introduction, we present a new algorithm to isolate Swiss cheese solutions characterized by “holes,” or small 4-cycles, descending from the toric divisors inherent to the original four dimensional reflexive polyhedra. Implementing these methods, we find 2268 explicit Swiss cheese manifolds, over half of which have h1,1=6. Many of our solutions have multiple large cycles. Such Swiss cheese geometries facilitate moduli stabilization in string compactifications and provide flat directions for cosmological inflation
Lidar observations of sporadic Na layers over Gadanki (13.5° N, 79.2° E)
International audienceWe studied the characteristics of sporadic sodium layers (SSLs) observed with the sodium (Na) resonance scattering lidar at Gadanki (13.5° N, 79.2° E). The SSLs were observed on a total of 63 occasions during 464 h of Na lidar observations from January 2005 to February 2006. The observations showed that one SSL event occurred, on average, every 7 h. The most prominent sporadic layer, which formed on 12 February 2005, exhibited a peak density of 60 722 Na atoms/cm³ around 92 km and it was nearly twice the peak density reported from elsewhere using ground-based observations. In general, the SSLs exhibited the following characteristics: (1) they developed at heights between 88 and 98 km with an average height around 94 km; (2) maximum density occurred during the early morning hours between 02:00 and 05:00 IST; (3) the ratio of the maximum peak Na density to the average density was normally around 3 to 5 and it exceeded even 10 in some cases; (4) the events lasted from a few minutes to several hours. The formation period of the SSLs was longer compared to the decay period of the SSLs. Most of the SSL events showed downward motions
Understanding Enhanced Boiling With Triton X Surfactants
Heat transfer performance in pool boiling is largely dictated by bubble growth, departure, and number of nucleation sites. It is a well known phenomenon that adding surfactants can lower the liquid-vapor surface tension and increase the bubble departure frequency, thereby enhancing heat transfer. In addition to faster departure rates, surfactants are observed to dramatically increase the number of nucleation sites, which cannot be explained by simple surface tension arguments. Furthermore, it is not well understood which surfactant properties such as chemical composition and molecular structure affect boiling most significantly. From our experiments using Triton X-100 and Triton X-114 nonionic surfactants, we attribute boiling enhancement mainly to adsorption to the solid-liquid interface. Using the Mikic-Rohsenow model for boiling, a simple linear adsorption model, and the Cassie-Baxter description for contact angle, we developed a model that shows agreement with experimental results. This work offers some insights on how to predict boiling enhancement based on surfactant chemistry alone, which may aid in choosing optimal surfactants for boiling in the future.National Science Foundation (U.S.). Materials Research Science and Engineering Centers (Program) (DMR - 0819762
Post-Harvest Behavior of Different Lettuce Cultivars and their Cut Form sunder Different Storage Conditions
The four leaf type lettuce cultivars i.e. GKL-1, GKL-2, GKL-3 and Chinese Yellow were evaluated for postharvest behavior during storage. The harvested fresh leaves of different lettuce cultivars were processed into two forms i.e. whole leaf form and cut form (5x3 cm) and were stored at two storage conditions i.e. refrigerated storage (5±1°C) and ZECC (9-15°C). Results revealed that whole leaf form of lettuce cultivars stored in refrigerated condition recorded minimum changes in physico-chemical parameters. With the advancement of storage period decrease in per cent moisture, ascorbic acid and polyphenol content was observed in all treatments irrespective of cultivars, forms and storage conditions. The maximum per cent browning and decay was observed in ZECC storage which was minimum in refrigerated storage.The whole leaf form of lettuce cultivar Chinese Yellow recorded shelf life of 15 days when stored at refrigerated storage (5±10C), whereas other cultivars (GKL-1, GKL-2 and GKL-3) recorded shelf life of 12 days. Whole leaf form of Lettuce cultivars stored in ZECC condition recorded shelf life upto 6 days while fresh-cut lettuce recorded shelf life of 3 days in ZECC. Fresh-cut lettuce recorded accelerated physiological loss in weight, moisture loss with increase in browning and decay percentage. Decrease in per cent moisture, ascorbic acid and polyphenol content with increase in physiological loss in weight was recorded in all treatments over the period of storage irrespective of cultivars, forms and storage conditions. The whole leaf form of lettuce cultivar Chinese Yellow recorded minimum changes in physico-chemical parameters and controlled enzymatic browning which maintained sensorial marketable quality and enhanced acceptability of lettuce leaves up to 15 days when stored at refrigerated storage (5±1°C)
D-branes on Singularities: New Quivers from Old
In this paper we present simplifying techniques which allow one to compute
the quiver diagrams for various D-branes at (non-Abelian) orbifold
singularities with and without discrete torsion. The main idea behind the
construction is to take the orbifold of an orbifold. Many interesting discrete
groups fit into an exact sequence . As such, the orbifold
is easier to compute as and we present graphical rules which
allow fast computation given the quiver.Comment: 25 pages, 13 figures, LaTe
Some observations on the beaked sea snake Enhydrina schistosa (Daudin, 1803) in the mudbank area, off Alapuzha, Kerala, southwest coast of India
Hook-nosed sea snake or beaked snake, Enhydrina schistosa
were caught during experimental fishing operations in the
mudbank region along central Kerala Coast at depths
ranging from 6 to 12 m. The sea snakes were found to
form aggregations of 5 to 6 numbers and were able to
tolerate highly turbid waters. The catfish Arius jella and the
puffer fish Lagocephalus inermis were the dominant prey
items. mudbanks are unusually calm areas which form
along the Kerala coast during the monsoon. The inshore
waters including the mudbanks are intense fishing areas of
non mechanized crafts during the monsoon. The presence
of venomous sea snakes is precarious and there is a need
to give awareness programme for the fishers about this
danger
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