27,305 research outputs found
The mathematical basis for deterministic quantum mechanics
If there exists a classical, i.e. deterministic theory underlying quantum
mechanics, an explanation must be found of the fact that the Hamiltonian, which
is defined to be the operator that generates evolution in time, is bounded from
below. The mechanism that can produce exactly such a constraint is identified
in this paper. It is the fact that not all classical data are registered in the
quantum description. Large sets of values of these data are assumed to be
indistinguishable, forming equivalence classes. It is argued that this should
be attributed to information loss, such as what one might suspect to happen
during the formation and annihilation of virtual black holes.
The nature of the equivalence classes is further elucidated, as it follows
from the positivity of the Hamiltonian. Our world is assumed to consist of a
very large number of subsystems that may be regarded as approximately
independent, or weakly interacting with one another. As long as two (or more)
sectors of our world are treated as being independent, they all must be
demanded to be restricted to positive energy states only. What follows from
these considerations is a unique definition of energy in the quantum system in
terms of the periodicity of the limit cycles of the deterministic model.Comment: 17 pages, 3 figures. Minor corrections, comments and explanations
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New broadband square-law detector
Compact device has wide dynamic range, accurate square-law response, good thermal stability, high-level dc output with immunity to ground-loop problems, ability to insert known time constants for radiometric applications, and fast response times compatible with computer systems
A new broadband square law detector
A broadband constant law detector was developed for precision power measurements, radio metric measurements, and other applications. It has a wide dynamic range and an accurate square law response. Other desirable characteristics, which are all included in a single compact unit, are: (1) high-level dc output with immunity to ground loop problems; (2) fast response times; (3) ability to insert known time constants; and (4) good thermal stability. The detector and its performance are described in detail. The detector can be operated in a programmable system with a ten-fold increase in accuracy. The use and performance of the detector in a noise-adding radiometer system is also discussed
Storage of correlated patterns in a perceptron
We calculate the storage capacity of a perceptron for correlated gaussian
patterns. We find that the storage capacity can be less than 2 if
similar patterns are mapped onto different outputs and vice versa. As long as
the patterns are in general position we obtain, in contrast to previous works,
that in agreement with Cover's theorem. Numerical simulations
confirm the results.Comment: 9 pages LaTeX ioplppt style, figures included using eps
On the center of mass of Ising vectors
We show that the center of mass of Ising vectors that obey some simple
constraints, is again an Ising vector.Comment: 8 pages, 3 figures, LaTeX; Claims in connection with disordered
systems have been withdrawn; More detailed description of the simulations;
Inset added to figure
Correlated patterns in non-monotonic graded-response perceptrons
The optimal capacity of graded-response perceptrons storing biased and
spatially correlated patterns with non-monotonic input-output relations is
studied. It is shown that only the structure of the output patterns is
important for the overall performance of the perceptrons.Comment: 4 pages, 4 figure
âMy journey through the systemâ: a grounded theory of service user-perceived experiences of recovery in forensic mental health services
The âRecovery Approachâ is widely regarded as the guiding principle for mentalhealth service delivery in the UK. Forensic services face unique challenges in applying this approach. Numerous studies have explored themes associated with recovery in these settings but it is unclear how themes relate to each other.
This study set out to build a theoretical model of service user experiences of recovery in forensic mental health settings. Semi-structured interviews were conducted with 16 service users about their recovery.
Grounded Theory methodology, with a constructivist epistemology, was used to analyse the data. A cyclical model was developed, with five-core recovery processes that interrelated; these were the environment, connectedness, hope for the future, who I am and empowerment. These occurred in three phases of 1) feeling safe and secure, 2) moving forward, and 3) empowerment. These processes were encompassed by two additional themes of arriving at the hospital and changes over time. This study is the first to provide a clear model of service user experiences of recovery in this setting
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