3,405 research outputs found
Study of large-scale mixing in developing wakes behind streamlined bodies
Heat-tagging and conditional sampling techniques were used to study the large scale mixing process in the developing wake behind a streamlined body. The results were used to understand the manner in which the large eddy length scale evolves from a value appropriate to a boundary layer to that appropriate to the asymptotic far-wake
Post phototherapy bilirubin rebound: incidence and risk factors
Background: Rebound hyperbilirubinemia may occur after cessation of phototherapy in new-borns in certain high-risk situations. However, data regarding the phenomenon of bilirubin rebound is lacking from India. Aim was to study the incidence and associated risk factors of post phototherapy rebound hyperbilirubinemia.Methods: The study subjects included all neonates (gestation >34 weeks) admitted to newborn unit who required phototherapy for hyperbilirubinemia. Unit protocol based on American academy of pediatrics (AAP) guidelines were used to start and stop phototherapy. Rebound bilirubin was measured 24±6 hours after stopping phototherapy. Significant bilirubin rebound (SBR) was defined as post phototherapy bilirubin level needing reinstitution of phototherapy. The risk factors associated with significant rebound were studied.Results: Out of total 509 neonates who received phototherapy due to hyperbilirubinemia, 63 (12%) had significant bilirubin rebound requiring reinstitution of phototherapy. There was significant risk for rebound in neonates who had prematurity (p <0.01), ABO (<0.001) and Rh incompatibility (p<0.005) with mother, G6PD deficiency (p < 0.001) and onset of hyperbilirubinemia less than 72 hours of postnatal age (p< 0.001). However, neonates with extravasations of blood, polycythaemia, sepsis, other causes of haemolysis and idiopathic group did not have significant risk of developing rebound.Conclusions: Post phototherapy bilirubin estimation and follow up should be ensured in high-risk neonates
CONSTRUCTION OF ASYMMETRICAL RESPONSE SURFACE DESIGNS
The paper proposes several methods for constructing both rotatable and non-rotatable asymmetrical response surface designs. The idea of modified rotatable design is introduced. In most of the experiments conducted by the experimenter it is not necessary that all the factors under study may have equal number of levels The methods proposed will have wider use under these circumstances
BLOCKING IN PARTIAL DIALLEL CROSSES
Generally the parents are included in the experimental material for combining ability analysis for comparing the performance of crosses with parents and also for calculating heterosis. But unfortunately the parents are ignored for combining ability analysis because of non-availability of analysis procedure. Method of analysis of partial diallel crosses in incomplete blocks for the method -2 of Griffing (1956) has been given
Electron transport properties of sub-3-nm diameter copper nanowires
Density functional theory and density functional tight-binding are applied to
model electron transport in copper nanowires of approximately 1 nm and 3 nm
diameters with varying crystal orientation and surface termination. The copper
nanowires studied are found to be metallic irrespective of diameter, crystal
orientation and/or surface termination. Electron transmission is highly
dependent on crystal orientation and surface termination. Nanowires oriented
along the [110] crystallographic axis consistently exhibit the highest electron
transmission while surface oxidized nanowires show significantly reduced
electron transmission compared to unterminated nanowires. Transmission per unit
area is calculated in each case, for a given crystal orientation we find that
this value decreases with diameter for unterminated nanowires but is largely
unaffected by diameter in surface oxidized nanowires for the size regime
considered. Transmission pathway plots show that transmission is larger at the
surface of unterminated nanowires than inside the nanowire and that
transmission at the nanowire surface is significantly reduced by surface
oxidation. Finally, we present a simple model which explains the transport per
unit area dependence on diameter based on transmission pathways results
Decentralized Reinforcement Learning: Global Decision-Making via Local Economic Transactions
This paper seeks to establish a framework for directing a society of simple,
specialized, self-interested agents to solve what traditionally are posed as
monolithic single-agent sequential decision problems. What makes it challenging
to use a decentralized approach to collectively optimize a central objective is
the difficulty in characterizing the equilibrium strategy profile of
non-cooperative games. To overcome this challenge, we design a mechanism for
defining the learning environment of each agent for which we know that the
optimal solution for the global objective coincides with a Nash equilibrium
strategy profile of the agents optimizing their own local objectives. The
society functions as an economy of agents that learn the credit assignment
process itself by buying and selling to each other the right to operate on the
environment state. We derive a class of decentralized reinforcement learning
algorithms that are broadly applicable not only to standard reinforcement
learning but also for selecting options in semi-MDPs and dynamically composing
computation graphs. Lastly, we demonstrate the potential advantages of a
society's inherent modular structure for more efficient transfer learning.Comment: 18 pages, 13 figures, accepted to the International Conference on
Machine Learning (ICML) 202
Partial Cholecystectomy Safe and Effective
Patients undergoing surgical treatment for calculous disease were considered to have had a partial
cholecystectomy performed when a part of the gall bladder wall was retained for technical reasons.
Forty patients underwent partial cholecystectomy: for chronic cholecystitis (20), acute cholecystitis (4),
Mirizzi's syndrome (14), portal hypertension or partially accesible gall bladder (one patient each). Four
patients (10%) developed infective complications and two patients had retained common bile duct
stones. In a mean follow up period of 13 months (range 1–36 mths), only 3 patients have ongoing mild
dyspeptic symptoms while the rest have remained asymptomatic. Partial cholecystectomy has been
found to be a safe and effective procedure in difficult cholecystectomy situations, since it combines the
merits of cholecystectomy and cholecystostomy
In-Line-Test of Variability and Bit-Error-Rate of HfOx-Based Resistive Memory
Spatial and temporal variability of HfOx-based resistive random access memory
(RRAM) are investigated for manufacturing and product designs. Manufacturing
variability is characterized at different levels including lots, wafers, and
chips. Bit-error-rate (BER) is proposed as a holistic parameter for the write
cycle resistance statistics. Using the electrical in-line-test cycle data, a
method is developed to derive BERs as functions of the design margin, to
provide guidance for technology evaluation and product design. The proposed BER
calculation can also be used in the off-line bench test and build-in-self-test
(BIST) for adaptive error correction and for the other types of random access
memories.Comment: 4 pages. Memory Workshop (IMW), 2015 IEEE Internationa
Magnetic field dependence of vortex activation energy: a comparison between MgB2, NbSe2 and Bi2Sr2Ca2Cu3O10 superconductors
The dissipative mechanism at low current density is compared in three
different classes of superconductors. This is achieved by measurement of
resistance as a function of temperature and magnetic field in clean
polycrystalline samples of NbSe2, MgB2 and Bi2Sr2Ca2Cu3O10 superconductors.
Thermally activated flux flow behavior is clearly identified in bulk MgB2.
While the activation energy at low fields for MgB2 is comparable to
Bi2Sr2Ca2Cu3O10, its field dependence follows a parabolic behavior unlike a
power law dependence seen in Bi2Sr2Ca2Cu3O10. We analyze our results based on
the Kramer's scaling for grain boundary pinning in MgB2and NbSe2
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