1,818 research outputs found
The Sheffield Wargames Corpus.
Recognition of speech in natural environments is a challenging task, even more so if this involves conversations between sev-eral speakers. Work on meeting recognition has addressed some of the significant challenges, mostly targeting formal, business style meetings where people are mostly in a static position in a room. Only limited data is available that contains high qual-ity near and far field data from real interactions between par-ticipants. In this paper we present a new corpus for research on speech recognition, speaker tracking and diarisation, based on recordings of native speakers of English playing a table-top wargame. The Sheffield Wargames Corpus comprises 7 hours of data from 10 recording sessions, obtained from 96 micro-phones, 3 video cameras and, most importantly, 3D location data provided by a sensor tracking system. The corpus repre-sents a unique resource, that provides for the first time location tracks (1.3Hz) of speakers that are constantly moving and talk-ing. The corpus is available for research purposes, and includes annotated development and evaluation test sets. Baseline results for close-talking and far field sets are included in this paper. 1
Requirements for tracking radar for falling spheres
Error analysis on radar tracking of falling sphere
Source-filter Separation of Speech Signal in the Phase Domain
Deconvolution of the speech excitation (source) and vocal tract
(filter) components through log-magnitude spectral processing
is well-established and has led to the well-known cepstral features
used in a multitude of speech processing tasks. This paper
presents a novel source-filter decomposition based on processing
in the phase domain. We show that separation between
source and filter in the log-magnitude spectra is far from
perfect, leading to loss of vital vocal tract information. It is
demonstrated that the same task can be better performed by
trend and fluctuation analysis of the phase spectrum of the
minimum-phase component of speech, which can be computed
via the Hilbert transform. Trend and fluctuation can be separated
through low-pass filtering of the phase, using additivity of
vocal tract and source in the phase domain. This results in separated
signals which have a clear relation to the vocal tract and
excitation components. The effectiveness of the method is put
to test in a speech recognition task. The vocal tract component
extracted in this way is used as the basis of a feature extraction
algorithm for speech recognition on the Aurora-2 database.
The recognition results shows upto 8.5% absolute improvement
in comparison with MFCC features on average (0-20dB)
Is small beautiful? A multicriteria assessment of small-scale energy technology applications in local governments
In its 2003 White Paper the UK government set ambitious renewable energy targets. Local governments and households have an increasing role in the overall energy system as consumers, suppliers of smaller-scale applications and citizens discussing energy projects. In this paper, we consider if small-scale or large-scale approaches to renewable energy provision can achieve energy targets in the most socially, economically and environmentally (SEE) effective way. We take a local case study of renewable energy provision in the Metropolitan Borough of Kirklees in Yorkshire, UK, and apply a multi-criteria decision analysis methodology to compare the small-scale schemes implemented in Kirklees with large-scale alternatives. The results indicate that small-scale schemes are the most SEE effective, despite large-scale schemes being more financially viable. The selection of the criteria on which the alternatives are assessed and the assigned weights for each criterion are of crucial importance. It is thus very important to include the relevant stakeholders to elicit this information
The impact of atmospheric pCO2 on carbon isotope ratios of the atmosphere and ocean
It is well known that the equilibration timescale for the isotopic ratios 13C/12C and 14C/12C in the ocean mixed layer is on the order of a decade, 2 orders of magnitude slower than for oxygen. Less widely appreciated is the fact that the equilibration timescale is quite sensitive to the speciation of dissolved inorganic carbon (DIC) in the mixed layer, scaling linearly with the ratio DIC/CO2, which varies inversely with atmospheric pCO2. Although this effect is included in models that resolve the role of carbon speciation in air-sea exchange, its role is often unrecognized, and it is not commonly considered in the interpretation of carbon isotope observations. Here we use a global three-dimensional ocean model to estimate the redistribution of the carbon isotopic ratios between the atmosphere and ocean due solely to variations in atmospheric pCO2. Under Last Glacial Maximum (LGM) pCO2, atmospheric Δ14C is increased by ~30‰ due to the speciation change, all else being equal, raising the surface reservoir age by about 250 years throughout most of the ocean. For 13C, enhanced surface disequilibrium under LGM pCO2 causes the upper ocean, atmosphere, and North Atlantic Deep Water δ13C to become at least 0.2‰ higher relative to deep waters ventilated by the Southern Ocean. Conversely, under high pCO2, rapid equilibration greatly decreases isotopic disequilibrium. As a result, during geological periods of high pCO2, vertical δ13C gradients may have been greatly weakened as a direct chemical consequence of the high pCO2, masquerading as very well ventilated or biologically dead Strangelove Oceans. The ongoing anthropogenic rise of pCO2 is accelerating the equilibration of the carbon isotopes in the ocean, lowering atmospheric Δ14C and weakening δ13C gradients within the ocean to a degree that is similar to the traditional fossil fuel “Suess” effect
Superpotentials for M-theory on a G_2 holonomy manifold and Triality symmetry
For -theory on the holonomy manifold given by the cone on {\bf
S^3}\x {\bf S^3} we consider the superpotential generated by membrane
instantons and study its transformations properties, especially under monodromy
transformations and triality symmetry. We find that the latter symmetry is,
essentially, even a symmetry of the superpotential. As in Seiberg/Witten
theory, where a flat bundle given by the periods of an universal elliptic curve
over the -plane occurs, here a flat bundle related to the Heisenberg group
appears and the relevant universal object over the moduli space is related to
hyperbolic geometry.Comment: 58 pages, latex; references adde
Enterobacter bugandensis: a novel enterobacterial species associated with severe clinical infection
Nosocomial pathogens can cause life-threatening infections in neonates and immunocompromised patients. E. bugandensis (EB-247) is a recently described species of Enterobacter, associated with neonatal sepsis. Here we demonstrate that the extended spectrum betha-lactam (ESBL) producing isolate EB-247 is highly virulent in both Galleria mellonella and mouse models of infection. Infection studies in a streptomycin-treated mouse model showed that EB-247 is as efficient as Salmonella Typhimurium in inducing systemic infection and release of proinflammatory cytokines. Sequencing and analysis of the complete genome and plasmid revealed that virulence properties are associated with the chromosome, while antibiotic-resistance genes are exclusively present on a 299 kb IncHI plasmid. EB-247 grew in high concentrations of human serum indicating septicemic potential. Using whole genome-based transcriptome analysis we found 7% of the genome was mobilized for growth in serum. Upregulated genes include those involved in the iron uptake and storage as well as metabolism. The lasso peptide microcin J25 (MccJ25), an inhibitor of iron-uptake and RNA polymerase activity, inhibited EB-247 growth. Our studies indicate that Enterobacter bugandensis is a highly pathogenic species of the genus Enterobacter. Further studies on the colonization and virulence potential of E. bugandensis and its association with septicemic infection is now warranted
Molecular epidemiology and characterization of an outbreak causing Klebsiella pneumoniae clone carrying chromosomally located bla CTX-M-15 at a German University-Hospital
Background: Multi-drug resistant Klebsiella pneumoniae strains are a common cause of health care associated infections worldwide. Clonal spread of Klebsiella pneumoniae isolates carrying plasmid mediated CTX-M-15 have been commonly reported. Limited data is available regarding dissemination of chromosomally encoded CTX-M-15 in Klebsiella pneumoniae worldwide.
Results: We examined 23 non-repetitive ESBL-producing Klebsiella pneumoniae strains isolated from clinical specimens over a period of 4 months in a German University Hospital. All isolates were characterized to determine their genetic relatedness using Pulsed-Field Gel Electrophoresis (PFGE) and Multi Locus Sequence Typing (MLST). PFGE revealed three clusters (B1, B2, and B3) with a sub-cluster (A3) comprising of 10 isolates with an identical PFGE pattern. All strains of the cluster B3 with similar PFGE patterns were typed as ST101, indicating an outbreak situation. The ESBL allele bla CTX-M-15 was identified in 16 (69.6 %) of all isolates, including all of the outbreak strains. Within the A3 sub-cluster, the CTX-M-15 allele could not be transferred by conjugation. DNA hybridization studies suggested a chromosomal location of bla CTX-M-15. Whole genome sequencing located CTX-M-15 within a complete ISEcp-1 transposition unit inserted into an ORF encoding for a putative membrane protein. PCR-based analysis of the flanking regions demonstrated that insertion into this region is unique and present in all outbreak isolates.
Conclusion: This is the first characterization of a chromosomal insertion of bla CTX-M-15 in Klebsiella pneumonia ST101, a finding suggesting that in Enterobacteriaceae, chromosomal locations may also act as reservoirs for the spread of bla CTX-M-15 encoding transposition units
An Initial Assessment of a SMAP Soil Moisture Disaggregation Scheme Using TIR Surface Evaporation Data over the Continental United States
The Soil Moisture Active Passive (SMAP) mission is dedicated toward global soil moisture mapping. Typically, an L-band microwave radiometer has spatial resolution on the order of 36-40 km, which is too coarse for many specific hydro-meteorological and agricultural applications. With the failure of the SMAP active radar within three months of becoming operational, an intermediate (9-km) and finer (3-km) scale soil moisture product solely from the SMAP mission is no longer possible. Therefore, the focus of this study is a disaggregation of the 36-km resolution SMAP passive-only surface soil moisture (SSM) using the Soil Evaporative Efficiency (SEE) approach to spatial scales of 3-km and 9-km. The SEE was computed using thermal-infrared (TIR) estimation of surface evaporation over Continental U.S. (CONUS). The disaggregation results were compared with the 3 months of SMAP-Active (SMAP-A) and Active/Passive (AP) products, while comparisons with SMAP-Enhanced (SMAP-E), SMAP-Passive (SMAP-P), as well as with more than 180 Soil Climate Analysis Network (SCAN) stations across CONUS were performed for a 19 month period. At the 9-km spatial scale, the TIR-Downscaled data correlated strongly with the SMAP-E SSM both spatially (r = 0.90) and temporally (r = 0.87). In comparison with SCAN observations, overall correlations of 0.49 and 0.47; bias of 0.022 and 0.019 and unbiased RMSD of 0.105 and 0.100 were found for SMAP-E and TIR-Downscaled SSM across the Continental U.S., respectively. At 3-km scale, TIR-Downscaled and SMAP-A had a mean temporal correlation of only 0.27. In terms of gain statistics, the highest percentage of SCAN sites with positive gains (>55%) was observed with the TIR-Downscaled SSM at 9-km. Overall, the TIR-based downscaled SSM showed strong correspondence with SMAP-E; compared to SCAN, and overall both SMAP-E and TIR-Downscaled performed similarly, however, gain statistics show that TIR-Downscaled SSM slightly outperformed SMAP-E
The Chandra Source Catalog
The Chandra Source Catalog (CSC) is a general purpose virtual X-ray
astrophysics facility that provides access to a carefully selected set of
generally useful quantities for individual X-ray sources, and is designed to
satisfy the needs of a broad-based group of scientists, including those who may
be less familiar with astronomical data analysis in the X-ray regime. The first
release of the CSC includes information about 94,676 distinct X-ray sources
detected in a subset of public ACIS imaging observations from roughly the first
eight years of the Chandra mission. This release of the catalog includes point
and compact sources with observed spatial extents <~ 30''. The catalog (1)
provides access to the best estimates of the X-ray source properties for
detected sources, with good scientific fidelity, and directly supports
scientific analysis using the individual source data; (2) facilitates analysis
of a wide range of statistical properties for classes of X-ray sources; and (3)
provides efficient access to calibrated observational data and ancillary data
products for individual X-ray sources, so that users can perform detailed
further analysis using existing tools. The catalog includes real X-ray sources
detected with flux estimates that are at least 3 times their estimated 1 sigma
uncertainties in at least one energy band, while maintaining the number of
spurious sources at a level of <~ 1 false source per field for a 100 ks
observation. For each detected source, the CSC provides commonly tabulated
quantities, including source position, extent, multi-band fluxes, hardness
ratios, and variability statistics, derived from the observations in which the
source is detected. In addition to these traditional catalog elements, for each
X-ray source the CSC includes an extensive set of file-based data products that
can be manipulated interactively.Comment: To appear in The Astrophysical Journal Supplement Series, 53 pages,
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