157 research outputs found
Recovery of anchovy (Engraulis anchoita) and whitemouth croaker (Micropogonias furnieri) proteins by alkaline solubilisation process
The aim of this study was to evaluate the physical, chemical, and functional properties of recovered proteins of anchovy (Engraulis anchoita) and whitemouth croaker (Micropogonias furnieri) through the process of alkaline solubilisation and isoelectric precipitation, using different solubilisation (NaOH and KOH) and precipitation (HCl and H3PO4) reagents. The tests showed high protein level, and the lowest lipid reduction (94.5%) was found in the recovered protein of anchovy, the lowest yield of the process was 76.1%. The highest whiteness (78.8 and 74.2) was found in whitemouth croaker proteins. The solubilisation of the recovered protein was studied in the pH range (3, 5, 7, 9, and 11). The maximum solubility was at pHs 3 and 11 and minimum solubility was at pH 5 in the species under study
Cyclostationary Processes on Shape Spaces for Gait-Based Recognition
Abstract. We present a geometric and statistical approach to gaitbased human recognition. The novelty here is to consider observations of gait, considered as planar silhouettes, to be cyclostationary processes on a shape space of simple closed curves. Consequently, gait analysis reduces to quantifying differences between underlying stochastic processes using their observations. Individual shapes can be compared using geodesic lengths, but the comparison of gait cycles requires tools for extraction, interpolation, registration, and averaging of individual gait cycles before comparisons. The main steps in our approach are: (i) off-line extraction of human silhouettes from IR video data, (ii) use of piecewise-geodesic paths, connecting the observed shapes, to smoothly interpolate between them, (iii) computation of an average gait cycle within class (i.e. associated with a person) using Karcher means, (iv) registration of average cycles using linear and nonlinear time scaling, (iv) comparisons of average cycles using geodesic lengths between the corresponding shapes. We illustrate this approach on gait sequence obtained from infrared video clips. Experimental results are presented for a data set of 26 subjects.
Anomalous dimensions of finite size field strength operators in N=4 SYM
In the N=4 super Yang-Mills theory, we consider the higher order anomalous
dimensions gamma_L(g) of purely gluonic operators Tr(F^L) where F is a
component of the self-dual field strength. We propose compact closed
expressions depending parametrically on L that reproduce the prediction of
Bethe Ansatz equations up to five loop order, including transcendental dressing
corrections. The size dependence follows a simple pattern as the perturbative
order is increased and suggests hidden relations for these special operators.Comment: 26 pages, 3 eps figures. v2: published version, minor changes,
references adde
A semi-classical limit of the gauge/string correspondence
A world-sheet sigma model approach is applied to string theories dual to
four-dimensional gauge theories, and semi-classical soliton solutions
representing highly excited string states are identified which correspond to
gauge theory operators with relatively small anomalous dimensions. The simplest
class of such states are strings on the leading Regge trajectory, with large
spin in AdS_5. These correspond to operators with many covariant derivatives,
whose anomalous dimension grows logarithmically with the space-time spin. In
the gauge theory, the logarithmic scaling violations are similar to those found
in perturbation theory. Other examples of highly excited string states are also
considered.Comment: 19 pages, latex, one figure. v2: references added, improved
discussion. v3: another ref added, minor corrections, version to appear in
NP
The Bethe-Ansatz for N=4 Super Yang-Mills
We derive the one loop mixing matrix for anomalous dimensions in N=4 Super
Yang-Mills. We show that this matrix can be identified with the Hamiltonian of
an integrable SO(6) spin chain with vector sites. We then use the Bethe ansatz
to find a recipe for computing anomalous dimensions for a wide range of
operators. We give exact results for BMN operators with two impurities and
results up to and including first order 1/J corrections for BMN operators with
many impurities. We then use a result of Reshetikhin's to find the exact
one-loop anomalous dimension for an SO(6) singlet in the limit of large bare
dimension. We also show that this last anomalous dimension is proportional to
the square root of the string level in the weak coupling limit.Comment: 35 pages, 3 figures, LaTeX; v2 references added, typos corrected,
\Lambda fixed; v3 expanded discussion of higher loops in conclusion, matches
published versio
On the covariant quantization of tensionless bosonic strings in AdS spacetime
The covariant quantization of the tensionless free bosonic (open and closed)
strings in AdS spaces is obtained. This is done by representing the AdS space
as an hyperboloid in a flat auxiliary space and by studying the resulting
string constrained hamiltonian system in the tensionless limit. It turns out
that the constraint algebra simplifies in the tensionless case in such a way
that the closed BRST quantization can be formulated and the theory admits then
an explicit covariant quantization scheme. This holds for any value of the
dimension of the AdS space.Comment: 1+16 pages; v4 two clarifications adde
Color superconductivity, Z_N flux tubes and monopole confinement in deformed N=2* super Yang-Mills theories
We study the Z_N flux tubes and monopole confinement in deformed N=2* super
Yang-Mills theories. In order to do that we consider an N=4 super Yang-Mills
theory with an arbitrary gauge group G and add some N=2, N=1 and N=0
deformation terms. We analyze some possible vacuum solutions and phases of the
theory, depending on the deformation terms which are added. In the Coulomb
phase for the N=2* theory, G is broken to U(1)^r and the theory has monopole
solutions. Then, by adding some deformation terms, the theory passes to the
Higgs or color superconducting phase, in which G is broken to its center C_G.
In this phase we construct the Z_N flux tubes ansatz and obtain the BPS string
tension. We show that the monopole magnetic fluxes are linear integer
combinations of the string fluxes and therefore the monopoles can become
confined. Then, we obtain a bound for the threshold length of the
string-breaking. We also show the possible formation of a confining system with
3 different monopoles for the SU(3) gauge group. Finally we show that the BPS
string tensions of the theory satisfy the Casimir scaling law.Comment: 18 pages, 2 figures, typo corrections. Version to appear in Phys.
Rev.
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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