2,565 research outputs found
Legendre transform structure and extremal properties of the relative Fisher information
Variational extremization of the relative Fisher information (RFI, hereafter) is performed. Reciprocity relations, akin to those of thermodynamics are derived, employing the extremal results of mthe RFI expressed in terms of probability amplitudes. A time independent Schrodinger-like equation (Schrodinger like link) for the RFI is derived. The concomitant Legendre transform structure (LTS hereafter) is developed by utilizing a generalized RFI-Euler theorem, which shows that the entire mathematical structure of htermodynamics translates into the RFI framework, both for equilibrium and non equilibrium cases. The qualitatevily distinct nature of the present results visd-a-vis those of prio studies utilizing the Shannon Entropy and/or the Fisher information mmeasure is discussed. A principled relationship between the RFI and the FIM ferameworks is derived. The utility of this relationship is demosnstrated by an example wherein the energy eigenvalues of the Schroedinger-like link for the RFI are inferred solely using the quantum mechanical virial theorem and the LTS of the RFI.Fil: Venkatesan, R. C.. Systems Research Corporation; IndiaFil: Plastino, Ángel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin
A stochastic model for sero conversion times of HIV transmission
This paper focuses on the study of a Stochastic Model for predicting the
seroconversion time of HIV transmission. As the immune capacities of an individual
vary and also have its own resistance, the antigenic diversity threshold is different
for different person. We propose a stochastic model to study the damage process
acting on the immune system that is non- linear. The mean of seroconversion time of
HIV and its variance are derived. A numerical example is given to illustrate the
seroconversion times of HIV transmission
Superconducting MgB2 thin films by pulsed laser deposition
Growth of MgB2 thin films by pulsed laser deposition is examined under ex
situ and in situ processing conditions. For the ex situ process, Boron films
grown by PLD were annealed at 900 C with excess Mg. For the in situ process,
different approaches involving ablation from a stoichiometric target under
different growth conditions, as well as multilayer deposition involving
interposed Mg layers were examined and analyzed. Magnetic measurements on ex
situ processed films show TC of ~39 K, while the current best in situ films
show a susceptibility transition at ~ 22 K.Comment: 3 pages, PD
Dissipation due to tunneling two-level systems in gold nanomechanical resonators
We present measurements of the dissipation and frequency shift in
nanomechanical gold resonators at temperatures down to 10 mK. The resonators
were fabricated as doubly-clamped beams above a GaAs substrate and actuated
magnetomotively. Measurements on beams with frequencies 7.95 MHz and 3.87 MHz
revealed that from 30 mK to 500 mK the dissipation increases with temperature
as , with saturation occurring at higher temperatures. The relative
frequency shift of the resonators increases logarithmically with temperature up
to at least 400 mK. Similarities with the behavior of bulk amorphous solids
suggest that the dissipation in our resonators is dominated by two-level
systems
Nonlinear modal coupling in a high-stress doubly-clamped nanomechanical resonator
We present results from a study of the nonlinear intermodal coupling between
different flexural vibrational modes of a single high-stress, doubly-clamped
silicon nitride nanomechanical beam. The measurements were carried out at 100
mK and the beam was actuated using the magnetomotive technique. We observed the
nonlinear behavior of the modes individually and also measured the coupling
between them by driving the beam at multiple frequencies. We demonstrate that
the different modes of the resonator are coupled to each other by the
displacement induced tension in the beam, which also leads to the well known
Duffing nonlinearity in doubly-clamped beams.Comment: 15 pages, 7 figure
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