521 research outputs found
Can the frequency-dependent specific heat be measured by thermal effusion methods?
It has recently been shown that plane-plate heat effusion methods devised for
wide-frequency specific-heat spectroscopy do not give the isobaric specific
heat, but rather the so-called longitudinal specific heat. Here it is shown
that heat effusion in a spherical symmetric geometry also involves the
longitudinal specific heat.Comment: Paper presented at the Fifth International Workshop on Complex
Systems (Sendai, September, 2007), to appear in AIP Conference Proceeding
Langevin Equation for the Rayleigh model with finite-ranged interactions
Both linear and nonlinear Langevin equations are derived directly from the
Liouville equation for an exactly solvable model consisting of a Brownian
particle of mass interacting with ideal gas molecules of mass via a
quadratic repulsive potential. Explicit microscopic expressions for all kinetic
coefficients appearing in these equations are presented. It is shown that the
range of applicability of the Langevin equation, as well as statistical
properties of random force, may depend not only on the mass ratio but
also by the parameter , involving the average number of molecules in
the interaction zone around the particle. For the case of a short-ranged
potential, when , analysis of the Langevin equations yields previously
obtained results for a hard-wall potential in which only binary collisions are
considered. For the finite-ranged potential, when multiple collisions are
important (), the model describes nontrivial dynamics on time scales
that are on the order of the collision time, a regime that is usually beyond
the scope of more phenomenological models.Comment: 21 pages, 1 figure. To appear in Phys. Rev.
Two-Dimensional Dynamic Fusion for Continuous Authentication
Continuous authentication has been widely studied to provide high security
and usability for mobile devices by continuously monitoring and authenticating
users. Recent studies adopt multibiometric fusion for continuous authentication
to provide high accuracy even when some of captured biometric data are of a low
quality. However, existing continuous fusion approaches are resource-heavy as
they rely on all classifiers being activated all the time and may not be
suitable for mobile devices.
In this paper, we propose a new approach to multibiometric continuous
authentication: two-dimensional dynamic fusion. Our key insight is that
multibiometric continuous authentication calculates two-dimensional matching
scores over classifiers and over time. Based on this, we dynamically select a
set of classifiers based on the context in which authentication is taking
place, and fuse matching scores by multi-classifier fusion and multi-sample
fusion. Through experimental evaluation, we show that our approach provides a
better balance between resource usage and accuracy than the existing fusion
methods. In particular, we show that our approach provides higher accuracy than
the existing methods with the same number of score calculations by adopting
multi-sample fusion.Comment: Accepted to IJCB'2
Diffusive Evolution of Stable and Metastable Phases II: Theory of Non-Equilibrium Behaviour in Colloid-Polymer Mixtures
By analytically solving some simple models of phase-ordering kinetics, we
suggest a mechanism for the onset of non-equilibrium behaviour in
colloid-polymer mixtures. These mixtures can function as models of atomic
systems; their physics therefore impinges on many areas of thermodynamics and
phase-ordering. An exact solution is found for the motion of a single, planar
interface separating a growing phase of uniform high density from a
supersaturated low density phase, whose diffusive depletion drives the
interfacial motion. In addition, an approximate solution is found for the
one-dimensional evolution of two interfaces, separated by a slab of a
metastable phase at intermediate density. The theory predicts a critical
supersaturation of the low-density phase, above which the two interfaces become
unbound and the metastable phase grows ad infinitum. The growth of the stable
phase is suppressed in this regime.Comment: 27 pages, Latex, eps
Time-convolutionless reduced-density-operator theory of a noisy quantum channel: a two-bit quantum gate for quantum information processing
An exact reduced-density-operator for the output quantum states in
time-convolutionless form was derived by solving the quantum Liouville equation
which governs the dynamics of a noisy quantum channel by using a projection
operator method and both advanced and retarded propagators in time. The
formalism developed in this work is general enough to model a noisy quantum
channel provided specific forms of the Hamiltonians for the system, reservoir,
and the mutual interaction between the system and the reservoir are given.
Then, we apply the formulation to model a two-bit quantum gate composed of
coupled spin systems in which the Heisenberg coupling is controlled by the
tunneling barrier between neighboring quantum dots. Gate Characteristics
including the entropy, fidelity, and purity are calculated numerically for both
mixed and entangled initial states
Crystal constructions in Number Theory
Weyl group multiple Dirichlet series and metaplectic Whittaker functions can
be described in terms of crystal graphs. We present crystals as parameterized
by Littelmann patterns and we give a survey of purely combinatorial
constructions of prime power coefficients of Weyl group multiple Dirichlet
series and metaplectic Whittaker functions using the language of crystal
graphs. We explore how the branching structure of crystals manifests in these
constructions, and how it allows access to some intricate objects in number
theory and related open questions using tools of algebraic combinatorics
Effect of temperature on rheology behaviour of banana peel pectin extracted using hot compressed water
Banana peel pectin is extracted from banana peel waste using a hot compressed water extraction (140-160°C, 5 minutes, 1.18 mm particle size). Physicochemical contents of banana peel pectin were found to be in a similar range with commercial pectin, and is comprised of moisture (7.44-8.47%), ash (3.45-4.98%), protein (1.08-1.92%), fat (0.04-3.42), carbohydrate (83-86%), total sugar (1.77-3.41%), energy (353-369 kcal/100g) and specific heat (1.42-1.62 kJ/kg°C). These contents possibly related to their flow deformation of rheological behaviour. Regression analysis displayed good agreements in all models applied, apart from the Casson Model. Flow behaviour indices, n<1 and decreasing of apparent viscosity within increasing of shear rate indicates that banana peel pectin has excellent shear thinning behaviour with a presence of yield stress
Circulating Levels of Resistin and Risk of Type 2 Diabetes in Men and Women: Results From Two Prospective Cohorts
OBJECTIVE—The purpose of this study was to investigate the role of circulating resistin levels in the development of type 2 diabetes using two prospective cohorts of well-characterized men and women
The Order Calculation in the Engineering Company
Import 23/07/2015Diplomová práce je zpracovávána ve společnosti Hagemann a.s. Celá práce se zabývá kalkulací veřejné zakázky Ministerstva vnitra ČR na dodání speciálně upravených policejních vozidel pro monitoring reálných hrozeb. Diplomová práce je rozdělena na dvě základní části, a to teoretickou část a praktickou část. První z částí je popsána problematika veřejných zakázek a hospodářská činnost v podniku. V druhé části je proveden rozbor předmětu veřejné zakázky. Dále byl zpracován návrh postupu plnění zakázky v prostorách společnosti, na které navazuje cenová kalkulace. V závěru práce jsou výsledky práce vyhodnoceny.Master thesis is processed in the company Hagemann a.s. The thesis deals with the calculation of public procurement from Ministry of the Interior to supply police vehicles specially adapted for monitoring real threats. The thesis is divided into two parts, the theoretical and practical part. The first part describes the issue of public procurement and economic activities in the company. The second part is analyzing subject of the contract. Further was processed a proposal for the execution of the contract in the company's premises, which is followed by a calculation and types of costs. In conclusion, the results of the work are evaluated.345 - Katedra mechanické technologievýborn
The DNA Glycosylases Ogg1 and Nth1 Do Not Contribute to Ig Class Switching in Activated Mouse Splenic B Cells
During activation of B cells to undergo class switching, B cell metabolism is increased, and levels of reactive oxygen species (ROS) are increased. ROS can oxidize DNA bases resulting in substrates for the DNA glycosylases Ogg1 and Nth1. Ogg1 and Nth1 excise oxidized bases, and nick the resulting abasic sites, forming single-strand DNA breaks (SSBs) as intermediates during the repair process. In this study, we asked whether splenic B cells from mice deficient in these two enzymes would show altered class switching and decreased DNA breaks in comparison with wild-type mice. As the c-myc gene frequently recombines with the IgH S region in B cells induced to undergo class switching, we also analyzed the effect of deletion of these two glycosylases on DSBs in the c-myc gene. We did not detect a reduction in S region or c-myc DSBs or in class switching in splenic B cells from Ogg1- or Nth1-deficient mice or from mice deficient in both enzymes
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