3,943 research outputs found
A Review of Audio Features and Statistical Models Exploited for Voice Pattern Design
Audio fingerprinting, also named as audio hashing, has been well-known as a
powerful technique to perform audio identification and synchronization. It
basically involves two major steps: fingerprint (voice pattern) design and
matching search. While the first step concerns the derivation of a robust and
compact audio signature, the second step usually requires knowledge about
database and quick-search algorithms. Though this technique offers a wide range
of real-world applications, to the best of the authors' knowledge, a
comprehensive survey of existing algorithms appeared more than eight years ago.
Thus, in this paper, we present a more up-to-date review and, for emphasizing
on the audio signal processing aspect, we focus our state-of-the-art survey on
the fingerprint design step for which various audio features and their
tractable statistical models are discussed.Comment: http://www.iaria.org/conferences2015/PATTERNS15.html ; Seventh
International Conferences on Pervasive Patterns and Applications (PATTERNS
2015), Mar 2015, Nice, Franc
Wireless Networks with Energy Harvesting and Power Transfer: Joint Power and Time Allocation
In this paper, we consider wireless powered communication networks which
could operate perpetually, as the base station (BS) broadcasts energy to the
multiple energy harvesting (EH) information transmitters. These employ "harvest
then transmit" mechanism, as they spend all of their energy harvested during
the previous BS energy broadcast to transmit the information towards the BS.
Assuming time division multiple access (TDMA), we propose a novel transmission
scheme for jointly optimal allocation of the BS broadcasting power and time
sharing among the wireless nodes, which maximizes the overall network
throughput, under the constraint of average transmit power and maximum transmit
power at the BS. The proposed scheme significantly outperforms "state of the
art" schemes that employ only the optimal time allocation. If a single EH
transmitter is considered, we generalize the optimal solutions for the case of
fixed circuit power consumption, which refers to a much more practical
scenario.Comment: 5 pages, 2 figures in IEEE Signal Processing Letters, vol. 23, no. 1,
January 201
Robust Beamforming for Secrecy Rate in Cooperative Cognitive Radio Multicast Communications
In this paper, we propose a cooperative approach to improve the security of
both primary and secondary systems in cognitive radio multicast communications.
During their access to the frequency spectrum licensed to the primary users,
the secondary unlicensed users assist the primary system in fortifying security
by sending a jamming noise to the eavesdroppers, while simultaneously protect
themselves from eavesdropping. The main objective of this work is to maximize
the secrecy rate of the secondary system, while adhering to all individual
primary users' secrecy rate constraints. In the case of passive eavesdroppers
and imperfect channel state information knowledge at the transceivers, the
utility function of interest is nonconcave and involved constraints are
nonconvex, and thus, the optimal solutions are troublesome. To address this
problem, we propose an iterative algorithm to arrive at a local optimum of the
considered problem. The proposed iterative algorithm is guaranteed to achieve a
Karush-Kuhn-Tucker solution.Comment: 6 pages, 4 figures, IEEE ICC 201
The Taurus Boundary of Stellar/Substellar (TBOSS) Survey I: far-IR disk emission measured with Herschel
With Herschel/PACS 134 low mass members of the Taurus star-forming region
spanning the M4-L0 spectral type range and covering the transition from low
mass stars to brown dwarfs were observed. Combining the new Herschel results
with other programs, a total of 150 of the 154 M4-L0 Taurus members members
have observations with Herschel. Among the 150 targets, 70um flux densities
were measured for 7 of the 7 ClassI objects, 48 of the 67 ClassII members, and
3 of the 76 ClassIII targets. For the detected ClassII objects, the median 70um
flux density level declines with spectral type, however, the distribution of
excess relative to central object flux density does not change across the
stellar/substellar boundary in the M4-L0 range. Connecting the 70um TBOSS
values with the results from K0-M3 ClassII members results in the first
comprehensive census of far-IR emission across the full mass spectrum of the
stellar and substellar population of a star-forming region, and the median flux
density declines with spectral type in a trend analogous to the flux density
decline expected for the central objects. SEDs were constructed for all TBOSS
targets covering the optical to far-IR range and extending to the submm/mm for
a subset of sources. Based on an initial exploration of the impact of different
physical parameters; inclination, scale height and flaring have the largest
influence on the PACS flux densities. From the 24um to 70um spectral index of
the SEDs, 5 new candidate transition disks were identified. The steep 24um to
70um slope for a subset of 8 TBOSS targets may be an indication of truncated
disks in these systems.Two examples of mixed pair systems that include
secondaries with disks were measured. Finally, comparing the TBOSS results with
a Herschel study of Ophiuchus brown dwarfs reveals a lower fraction of disks
around the Taurus substellar population.Comment: 64 pages, 33 figures, 12 tables, accepted for publication in A&
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