5,524 research outputs found
Fermion-parity duality and energy relaxation in interacting open systems
We study the transient heat current out of a confined electron system into a
weakly coupled electrode in response to a voltage switch. We show that the
decay of the Coulomb interaction energy for this repulsive system exhibits
signatures of electron-electron attraction, and is governed by an
interaction-independent rate. This can only be understood from a general
duality that relates the non-unitary evolution of a quantum system to that of a
dual model with inverted energies. Deriving from the fermion-parity
superselection postulate, this duality applies to a large class of open
systems.Comment: 5 pages + 19 pages of Supplementary Materia
Selection of medical students - a follow-up study
The attributes of 1026 medical students admitted to university on academic criteria and by interview between 1980 and 1983, and the characteristics of 822 of them who graduated between 1985 and 1988, were analysed. There were 133 students (13%) who failed and were excluded, 99 (10%) repeated 1 or more years of study, 67 (7%) voluntarily withdrew, 42 (4%) completed a Bsc. degree during their medical training, and 675 graduated in the minimum' time. The admitted and graduated students were mainly white (85%), male (67%) and had no academic experience other than matriculation (69%). During the review period the proportion of 'non-whites', women and applicants with university experience increased. Students who voluntarily withdrew had significantly low interview scores; applicants with university experience and applicants who subsequently failed. had significanUy high interview scores. It is concluded that the interview is useful, that the demographic characteristics of the classes are changing, and that traditional academic standards have been maintained
Development of the National Home and Hospice Care Survey
[by Barbara J. Haupt]."August 1994."Also available via the World Wide Web.Includes bibliographical references (p. 18)
Leakage in restless quantum gate calibration
Quantum computers require high fidelity quantum gates. These gates are
obtained by routine calibration tasks that eat into the availability of
cloud-based devices. Restless circuit execution speeds-up characterization and
calibration by foregoing qubit reset in between circuits. Post-processing the
measured data recovers the desired signal. However, since the qubits are not
reset, leakage -- typically present at the beginning of the calibration -- may
cause issues. Here, we develop a simulator of restless circuit execution based
on a Markov Chain to study the effect of leakage. In the context of error
amplifying single-qubit gates sequences, we show that restless calibration
tolerates up to 0.5% of leakage which is large compared to the gate
fidelity of modern single-qubit gates. Furthermore, we show that restless
circuit execution with leaky gates reduces by 33% the sensitivity of the ORBIT
cost function developed by J. Kelly et al. which is typically used in
closed-loop optimal control~[Phys. Rev. Lett. 112, 240504 (2014)]. Our results
are obtained with standard qubit state discrimination showing that restless
circuit execution is resilient against misclassified non-computational states.
In summary, the restless method is sufficiently robust against leakage in both
standard and closed-loop optimal control gate calibration to provided accurate
results
Improved bounds for sparse recovery from adaptive measurements
It is shown here that adaptivity in sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. An adaptive sampling-and-refinement procedure called distilled sensing is discussed and analyzed, resulting in fundamental new asymptotic scaling relationships in terms of the minimum feature strength required for reliable signal detection or localization (support recovery). In particular, reliable detection and localization using non-adaptive samples is possible only if the feature strength grows logarithmically in the problem dimension. Here it is shown that using adaptive sampling, reliable detection is possible provided the feature strength exceeds a constant, and localization is possible when the feature strength exceeds any (arbitrarily slowly) growing function of the problem dimension
Biodiversity and Ecosystem Health of the Aldabra Group, Southern Seychelles: Scientific Report to the Government of Seychelles.
National Geographic's Pristine Seas project, in collaboration with the government of the Seychelles, the Island Conservation Society (ICS), the Seychelles Islands Foundation (SIF), and the Waitt Foundation, conducted an expedition to explore the poorly known marine environment around these islands. The goals were to assess the biodiversity of the nearshore marine environment and to survey the largely unknown deep sea realm. The data collected contribute to the marine spatial planning of the Seychelles, in particular the creation of large marine reserves
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