106 research outputs found
Performance Considerations for an Embedded Implementation of OMA DRM 2
As digital content services gain importance in the mobile world, Digital
Rights Management (DRM) applications will become a key component of mobile
terminals. This paper examines the effect dedicated hardware macros for
specific cryptographic functions have on the performance of a mobile terminal
that supports version 2 of the open standard for Digital Rights Management
defined by the Open Mobile Alliance (OMA). Following a general description of
the standard, the paper contains a detailed analysis of the cryptographic
operations that have to be carried out before protected content can be
accessed. The combination of this analysis with data on execution times for
specific algorithms realized in hardware and software has made it possible to
build a model which has allowed us to assert that hardware acceleration for
specific cryptographic algorithms can significantly reduce the impact DRM has
on a mobile terminal's processing performance and battery life.Comment: Submitted on behalf of EDAA (http://www.edaa.com/
Hidden Modulus in the Extended Veneziano-Yankielowicz Theory
The issue of domain walls in the recently extended Veneziano-Yankielowicz
theory is investigated and we show that they have an interesting substructure.
We also demonstrate the presence of a noncompact modulus. The associated family
of degenerate solutions is physically due to the presence of a valley of vacua
in the enlarged space of fields. This is a feature of the extended
Veneziano-Yankielowicz theory. Unfortunately the above properties do not match
the ones expected for the domain walls of N=1 super Yang-Mills.Comment: LaTeX, 13 pages and 5 figs, v3 misprints correcte
Improved Performances of a Fluidized Bed Photoreactor by a Microscale Illumination System
The performances of a gas-solid two-dimensional fluidized bed reactor in photocatalytic selective oxidation reactions, irradiated with traditional UV lamps or with a microscale illumination system based on UV emitting diodes (UVA-LEDs), have been compared. In the photocatalytic oxidative dehydrogenation of cyclohexane to benzene on catalyst the use of UVA-LEDs modules allowed to achieve a cyclohexane conversion and benzene yield higher than those obtained with traditional UV lamps. The better performances with UVA-LEDs are due to the UVA-LEDs small dimensions and small-angle emittance, which allow photons beam be directed towards the photoreactor windows, reducing the dispersion outside of photoreactor or the optical path length. As a consequence, the effectively illuminated mass of catalyst is greater. We have found that this illumination system is efficient for photo-oxidative dehydrogenation of cyclohexane to cyclohexene on sulphated and ethanol to acetaldehyde on
Efficient Continuous Beam Steering for Planar Arrays of Differential Microphones
Performing continuous beam steering, from planar arrays of high-order differential microphones, is not trivial. The main problem is that shape-preserving beams can be steered only in a finite set of privileged directions, which depend on the position and the number of physical microphones. In this letter, we propose a simple and computationally inexpensive method for alleviating this problem using planar microphone arrays. Given two identical reference beams pointing in two different directions, we show how to build a beam of nearly constant shape, which can be continuously steered between such two directions. The proposed method, unlike the diffused steering approaches based on linear combinations of eigenbeams (spherical harmonics), is applicable to planar arrays also if we deal with beams characterized by high-order polar patterns. Using the coefficients of the Fourier series of the polar patterns, we also show how to find a tradeoff between shape invariance of the steered beam, and maximum angular displacement between the two reference beams. We show the effectiveness of the proposed method through the analysis of models based on first-, second-, and third-order differential microphones
N=1 Matter from Fractional Branes
We study a bound state of fractional D3-branes localized inside the
world-volume of fractional D7-branes on the orbifold C^3/Z_2 x Z_2. We
determine the open string spectrum that leads to N=1 U(N1)xU(N2)xU(N3)xU(N4)
gauge theory with matter having the number of D7-branes as a flavor index. We
derive the linearized boundary action of the D7-brane on this orbifold using
the boundary state formalism and we discuss the tadpole cancellation. After
computing the asymptotic expression of the supergravity solution the anomalies
of the gauge theory are reproduced.Comment: LaTeX 20 pages, 1 figure, small changes and references adde
Improved Performances of a Fluidized Bed Photoreactor by a Microscale Illumination System
The performances of a gas-solid two-dimensional fluidized bed reactor in photocatalytic selective oxidation reactions, irradiated with traditional UV lamps or with a microscale illumination system based on UV emitting diodes (UVA-LEDs), have been compared. In the photocatalytic oxidative dehydrogenation of cyclohexane to benzene on MoOx/TiO2-A12O3
catalyst the use of UVA-LEDs modules allowed to achieve a cyclohexane conversion and benzene yield higher than those obtained with traditional UV lamps. The better performances with UVA-LEDs are due to the UVA-LEDs small dimensions and small-angle emittance, which allow photons beam be directed towards the photoreactor windows, reducing the dispersion outside of photoreactor or the optical path length. As a consequence, the effectively illuminated mass of catalyst is greater. We have found that this illumination system is efficient for photo-oxidative dehydrogenation of cyclohexane to cyclohexene on sulphated MoOx/-A12O3
and ethanol to acetaldehyde on VOx/TiO2
Yield, quality, antioxidants and elemental composition of peanut as affected by plant density and harvest time
With the perspective of reintroducing peanut cultivation in southern Italy about six decades
after its dismissal, research was carried out with the aim to identify the best performing farming management in terms of yield and quality. In this respect, the effect of the factorial combination between four
plant densities (6.1, 7.8, 10.3, and 12.1 plants m-2) and two harvest times (100 and 110 days after planting) was assessed on pod and seed yield, as well as on seed quality, antioxidant activity, and elemental
composition. The later harvest time determined a 26.9% dry weight increase, but a 14.3% decrease in the
number of seeds per pod. Plant density significantly influenced all the yield and growth indices except
for mean seed weight. Yield and growth of each plant were best affected by the lowest plant density,
whereas the opposite trend was recorded for the same parameters referred to the surface area unit. The
density of 12.1 plants m-2 resulted in a 32% reduction in pods per plant compared to 6.1 plants m-2, but
had the greatest effect on seed production per m2
. The leaf area index was the highest with the density of
12.1 plants m-2. The total dry weight increased by 1.7-fold from 6.1 to 12.1 plants m-2. Compared to the
first harvest time, in the second one the protein content decreased by 6.8%, and total polyphenols and
antioxidant activity decreased by 11.2% and 7.6%, respectively. The second harvest time led to a depletion of N, P, and Mg, by 6.8%, 6.2%, and 6.8%, respectively, and a 7.1% Ca increase. The reintroduction
of peanut cultivation in southern Italy is a realistic goal, though further studies regarding the crop system
management are needed
Low Energy Theory for 2 flavors at High Density QCD
We construct the effective Lagrangian describing the low energy excitations
for Quantum Chromodynamics with two flavors at high density. The non-linear
realization framework is employed to properly construct the low energy
effective theory. The light degrees of freedom, as required by 't Hooft anomaly
conditions, contain massless fermions which we properly include in the
effective Lagrangian. We also provide a discussion of the linearly realized
Lagrangian.Comment: 17 pages, RevTeX format, references added. To appear in Phys. Rev.
Electroweak Physics for Color Superconductivity
We construct the effective theories describing the electroweak interactions
for the low energy excitations associated with the color superconductive phases
of QCD at high matter density. The main result, for the 3 flavor case, is that
the quasiparticle Goldstone boson decay into two physical massless
photons is identical to the zero density case once we use the new Goldstone
decay constant and the modified electric charge ,
with and the strong coupling constant. For 2
flavors we find that the coupling of the quarks to the neutral vector boson
is modified with respect to the zero density case. We finally point out
possible applications of our result to the physics of compact objects.Comment: 23 pages, 1 Figure, RevTex. More discussion and references adde
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