754 research outputs found
The entropy reduction engine: Integrating planning, scheduling, and control
The Entropy Reduction Engine, an architecture for the integration of planning, scheduling, and control, is described. The architecture is motivated, presented, and analyzed in terms of its different components; namely, problem reduction, temporal projection, and situated control rule execution. Experience with this architecture has motivated the recent integration of learning. The learning methods are described along with their impact on architecture performance
Universal relaxational dynamics of gapped one dimensional models in the quantum sine-Gordon universality class
A semiclassical approach to the low-temperature real time dynamics of generic
one-dimensional, gapped models in the sine-Gordon model universality class is
developed. Asymptotically exact universal results for correlation functions are
obtained in the temperature regime T << Delta, where Delta is the energy gap.Comment: 4 pages, 1 figur
The blind leading the blind: Mutual refinement of approximate theories
The mutual refinement theory, a method for refining world models in a reactive system, is described. The method detects failures, explains their causes, and repairs the approximate models which cause the failures. The approach focuses on using one approximate model to refine another
Symmetry breaking perturbations and strange attractors
The asymmetrically forced, damped Duffing oscillator is introduced as a
prototype model for analyzing the homoclinic tangle of symmetric dissipative
systems with \textit{symmetry breaking} disturbances. Even a slight fixed
asymmetry in the perturbation may cause a substantial change in the asymptotic
behavior of the system, e.g. transitions from two sided to one sided strange
attractors as the other parameters are varied. Moreover, slight asymmetries may
cause substantial asymmetries in the relative size of the basins of attraction
of the unforced nearly symmetric attracting regions. These changes seems to be
associated with homoclinic bifurcations. Numerical evidence indicates that
\textit{strange attractors} appear near curves corresponding to specific
secondary homoclinic bifurcations. These curves are found using analytical
perturbational tools
Cyclic mutually unbiased bases, Fibonacci polynomials and Wiedemann's conjecture
We relate the construction of a complete set of cyclic mutually unbiased
bases, i. e., mutually unbiased bases generated by a single unitary operator,
in power-of-two dimensions to the problem of finding a symmetric matrix over
F_2 with an irreducible characteristic polynomial that has a given Fibonacci
index. For dimensions of the form 2^(2^k) we present a solution that shows an
analogy to an open conjecture of Wiedemann in finite field theory. Finally, we
discuss the equivalence of mutually unbiased bases.Comment: 11 pages, added chapter on equivalenc
Non-ergodicity of the motion in three dimensional steep repelling dispersing potentials
It is demonstrated numerically that smooth three degrees of freedom
Hamiltonian systems which are arbitrarily close to three dimensional strictly
dispersing billiards (Sinai billiards) have islands of effective stability, and
hence are non-ergodic. The mechanism for creating the islands are corners of
the billiard domain.Comment: 6 pages, 8 figures, submitted to Chao
Parabolic resonances and instabilities in near-integrable two degrees of freedom Hamiltonian flows
When an integrable two-degrees-of-freedom Hamiltonian system possessing a
circle of parabolic fixed points is perturbed, a parabolic resonance occurs. It
is proved that its occurrence is generic for one parameter families
(co-dimension one phenomenon) of near-integrable, t.d.o. systems. Numerical
experiments indicate that the motion near a parabolic resonance exhibits new
type of chaotic behavior which includes instabilities in some directions and
long trapping times in others. Moreover, in a degenerate case, near a {\it flat
parabolic resonance}, large scale instabilities appear. A model arising from an
atmospherical study is shown to exhibit flat parabolic resonance. This supplies
a simple mechanism for the transport of particles with {\it small} (i.e.
atmospherically relevant) initial velocities from the vicinity of the equator
to high latitudes. A modification of the model which allows the development of
atmospherical jets unfolds the degeneracy, yet traces of the flat instabilities
are clearly observed
Prescription auditing: an important tool for sensitization of resident doctors for rationale prescription and utilization of drug
Background: The main objective of the Maharashtra Health Systems Development Project (MHSDP) is to enhance the quality of care by improving health care; in the hospitals, in the state. Improvement in the prescribing practice of resident doctors working in the hospitals is one of the initiatives taken up, to improve the rationalizing service delivery. A prescription audit may become an important tool for sensitizing resident doctors for rational prescription and utilization of drug.Methods: An observational study was carried out during the period of March 2017 to May 2017 in tertiary care teaching hospital, Kolhapur. Total 247 first prescriptions written by resident for in-door-patient department were collected, scrutinized and analysed. Prescriptions were evaluated for completeness of prescription format while legibility was graded. Prescriptions were also analysed as per World Health Organization prescribing indicators.Results: In study 247 prescriptions with 1091 drugs with average 4.42% drugs per prescription, 49.8 % prescriptions wrote the drugs by generic name. We found that 44.1 % prescriptions written with drugs included in essential medicines list while antibiotics prescribed were 27.1%. In prescription format 34% had incorrect dosage, 67% of prescriptions omitted the duration of treatment. Direction for drug use was not mentioned in 25% of prescriptions. Weight was not mentioned on any prescriptions even for paediatric group.Conclusions: Through prescription auditing, sensitizing resident doctors for rational prescription and utilization of drug can be done to achieve the goal of the MHSDP of enhancing the quality of care by improving health care; in the hospitals, in the state
Stickiness in Hamiltonian systems: from sharply divided to hierarchical phase space
We investigate the dynamics of chaotic trajectories in simple yet physically
important Hamiltonian systems with non-hierarchical borders between regular and
chaotic regions with positive measures. We show that the stickiness to the
border of the regular regions in systems with such a sharply divided phase
space occurs through one-parameter families of marginally unstable periodic
orbits and is characterized by an exponent \gamma= 2 for the asymptotic
power-law decay of the distribution of recurrence times. Generic perturbations
lead to systems with hierarchical phase space, where the stickiness is
apparently enhanced due to the presence of infinitely many regular islands and
Cantori. In this case, we show that the distribution of recurrence times can be
composed of a sum of exponentials or a sum of power-laws, depending on the
relative contribution of the primary and secondary structures of the hierarchy.
Numerical verification of our main results are provided for area-preserving
maps, mushroom billiards, and the newly defined magnetic mushroom billiards.Comment: To appear in Phys. Rev. E. A PDF version with higher resolution
figures is available at http://www.pks.mpg.de/~edugal
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