8,045 research outputs found
Classical Signal Model for Quantum Channels
Recently it was shown that the main distinguishing features of quantum
mechanics (QM) can be reproduced by a model based on classical random fields,
so called prequantum classical statistical field theory (PCSFT). This model
provides a possibility to represent averages of quantum observables, including
correlations of observables on subsystems of a composite system (e.g.,
entangled systems), as averages with respect to fluctuations of classical
(Gaussian) random fields. In this note we consider some consequences of PCSFT
for quantum information theory. They are based on the observation \cite{W} of
two authors of this paper that classical Gaussian channels (important in
classical signal theory) can be represented as quantum channels. Now we show
that quantum channels can be represented as classical linear transformations of
classical Gaussian signa
A study on PDC drill bits quality
The quality of innovating PDC (Polycrystalline Diamond Compact) bits materials needs to be determined with accuracy by measuring cutting efficiency and wear rate, both related to the overall mechanical properties. An original approach is developed to encompass cutting efficiency and wear contribution to the overall sample quality. Therefore, a lathe-type test device was used to abrade specific samples from various manufacturers. Post-experiment analyzes are based on models establishing coupled relationships between cutting and friction stresses related to the drag bits excavation mechanism. These models are implemented in order to evaluate cutting efficiency and to estimate wear of the diamond insert. Phase analysis by XRD and finite element simulations were performed to explain the role of physicochemical parameters on the calculated quality factor values. Four main properties of PDC material were studied to explain quality results obtained in this study: cobalt content in samples that characterizes hardness/fracture toughness compromise, undesired phase as tungsten carbide weakening diamond structure, diamond grains sizes and residual stresses distribution affecting abrasion resistance
Brownian Entanglement
We show that for two classical brownian particles there exists an analog of
continuous-variable quantum entanglement: The common probability distribution
of the two coordinates and the corresponding coarse-grained velocities cannot
be prepared via mixing of any factorized distributions referring to the two
particles in separate. This is possible for particles which interacted in the
past, but do not interact in the present. Three factors are crucial for the
effect: 1) separation of time-scales of coordinate and momentum which motivates
the definition of coarse-grained velocities; 2) the resulting uncertainty
relations between the coordinate of the brownian particle and the change of its
coarse-grained velocity; 3) the fact that the coarse-grained velocity, though
pertaining to a single brownian particle, is defined on a common context of two
particles. The brownian entanglement is a consequence of a coarse-grained
description and disappears for a finer resolution of the brownian motion. We
discuss possibilities of its experimental realizations in examples of
macroscopic brownian motion.Comment: 18 pages, no figure
Developing a Business Case for the Care Coordination and Transition Management Model: Needs, Methods, and Measures
In this descriptive qualitative study, nurse and healthcare leaders\u27 experiences, perceptions of care coordination and transition management (CCTM®), and insights as to how to foster adoption of the CCTM RN role in nursing education, practice across the continuum, and policy were explored. Twenty-five barriers to recognition and adoption of CCTM RN practice across the continuum were identified and categorized. Implications of these findings, recommendations for adoption of CCTM RN practice across the care continuum, and strategies for reimbursement policies are discussed
Derivation of the Planck Spectrum for Relativistic Classical Scalar Radiation from Thermal Equilibrium in an Accelerating Frame
The Planck spectrum of thermal scalar radiation is derived suggestively
within classical physics by the use of an accelerating coordinate frame. The
derivation has an analogue in Boltzmann's derivation of the Maxwell velocity
distribution for thermal particle velocities by considering the thermal
equilibrium of noninteracting particles in a uniform gravitational field. For
the case of radiation, the gravitational field is provided by the acceleration
of a Rindler frame through Minkowski spacetime. Classical zero-point radiation
and relativistic physics enter in an essential way in the derivation which is
based upon the behavior of free radiation fields and the assumption that the
field correlation functions contain but a single correlation time in thermal
equilibrium. The work has connections with the thermal effects of acceleration
found in relativistic quantum field theory.Comment: 23 page
Born's rule from measurements of classical signals by threshold detectors which are properly calibrated
The very old problem of the statistical content of quantum mechanics (QM) is
studied in a novel framework. The Born's rule (one of the basic postulates of
QM) is derived from theory of classical random signals. We present a
measurement scheme which transforms continuous signals into discrete clicks and
reproduces the Born's rule. This is the sheme of threshold type detection.
Calibration of detectors plays a crucial role.Comment: The problem of double clicks is resolved; hence, one can proceed in
purely wave framework, i.e., the wave-partcile duality has been resolved in
favor of the wave picture of prequantum realit
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