1,669 research outputs found
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mGPT: A Probabilistic Planner Based on Heuristic Search
We describe the version of the GPT planner used in the probabilistic track of
the 4th International Planning Competition (IPC-4). This version, called mGPT,
solves Markov Decision Processes specified in the PPDDL language by extracting
and using different classes of lower bounds along with various heuristic-search
algorithms. The lower bounds are extracted from deterministic relaxations where
the alternative probabilistic effects of an action are mapped into different,
independent, deterministic actions. The heuristic-search algorithms use these
lower bounds for focusing the updates and delivering a consistent value
function over all states reachable from the initial state and the greedy
policy
Reconstruction of velopharyngeal sphincter in secondary Cleft Palate: surgical alternative
Cir Pediatr. 2006 Apr;19(2):106-10.
[Reconstruction of velopharyngeal sphincter in secondary Cleft Palate: surgical alternative]
[Article in Spanish]
Recamán M, Bonet B, Leitão J, Mesquita A.
Hospital Central e Especializado de Crianças Maria Pia, Serviço de CirurgÃa Plástica. [email protected]
Abstract
There are numerous surgical procedures for the repair of Cleft Palate (CP). Since 1998, in children with CP we use a modified Wardill-Kilner technique, with a large section of the nasal mucous layer at the level of the muscular insertion on the hard palate and lateral nasopharingeal wall, obtaining a push-back and reorientation of the muscular fibres without dissection, diminishing this way the risks of haemorrhages and fibrosis, simplifying the intervention. It allows a lower operative time and a short internment. The aim of our study was to evaluate the results of this operative procedure specially in the development of the speech in 73 children operated on from 1998 until 2000 in our hospital. We verify a competence of the velopharingeal sphincter with ideal results in speech in 88,8% of the cases.
PMID: 16846134 [PubMed - indexed for MEDLIN
Calculating energy derivatives for quantum chemistry on a quantum computer
Modeling chemical reactions and complicated molecular systems has been
proposed as the `killer application' of a future quantum computer. Accurate
calculations of derivatives of molecular eigenenergies are essential towards
this end, allowing for geometry optimization, transition state searches,
predictions of the response to an applied electric or magnetic field, and
molecular dynamics simulations. In this work, we survey methods to calculate
energy derivatives, and present two new methods: one based on quantum phase
estimation, the other on a low-order response approximation. We calculate
asymptotic error bounds and approximate computational scalings for the methods
presented. Implementing these methods, we perform the world's first geometry
optimization on an experimental quantum processor, estimating the equilibrium
bond length of the dihydrogen molecule to within 0.014 Angstrom of the full
configuration interaction value. Within the same experiment, we estimate the
polarizability of the H2 molecule, finding agreement at the equilibrium bond
length to within 0.06 a.u. (2% relative error).Comment: 19 pages, 1 page supplemental, 7 figures. v2 - tidied up and added
example to appendice
Holography and Variable Cosmological Constant
An effective local quantum field theory with UV and IR cutoffs correlated in
accordance with holographic entropy bounds is capable of rendering the
cosmological constant (CC) stable against quantum corrections. By setting an IR
cutoff to length scales relevant to cosmology, one easily obtains the currently
observed rho_Lambda ~ 10^{-47} GeV^4, thus alleviating the CC problem. It is
argued that scaling behavior of the CC in these scenarios implies an
interaction of the CC with matter sector or a time-dependent gravitational
constant, to accommodate the observational data.Comment: 7 pages, final version accepted by PR
Assessment of Heavy Metals Level of River Kaduna at Kaduna Metropolis, Nigeria
River Kaduna which serves as source of water for farming, domestic and industrial uses suffers enormous pollution as a result of industrial activities and other anthropogenic sources of contamination. The study determines the concentration of some selected heavy metal of the surface waters of River Kaduna, examines the pollution status and the implications of the heavy metal pollution on human health and the environment. The water Samples were collected using Grab method along the River Kaduna at five points – Bypass, Barnawa, Down quarters, Kakuri – Makera drains and Kudendan. Six samples during the rainy season and another during the dry season. The samples were taken to the laboratory and analyzed for chromium, Arsenic, Iron, copper, Berium, Aluminium, Cadmium, Cyanide and zinc using Atomic Absorption Spectrophotometer. The results obtained from the analysis were compared with the World Health Organization (WHO) recommended standards in order to ascertain the magnitude of pollution and the quality of the water. The concentrations of the metals were observed to be higher than WHO acceptable limits. This revealed that the river have become contaminated by heavy metals discharged into the river especially from the industries and municipal wastes and may cause serious ecological and health hazards. The paper recommends that there should be proper monitoring of effluents, there is the need for mass education of people on the impact of indiscriminate waste discharge on the water quality, and a regular schedule for sampling tributary streams and the main river Kaduna should be established. Keywords: Heavy metals, Pollution, Hazard, Environment, Industrial Wastes and Effluents
Identification of barely visible impact damages on a stiffened composite panel with a probability-based approach
A probability-based damage detection algorithm has been implemented in order to identify barely visible impact damages in two composite stiffened panels by means of Acousto Ultrasonics (AU). A modification of RAPID (reconstruction algorithm for probabilistic inspection of defects) has been implemented to adapt the algorithm to the current structures and transducer networks. An improvement of 40% in the localization accuracy is obtained with the new algorith
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