9,178 research outputs found
Synthesis of Recursive ADT Transformations from Reusable Templates
Recent work has proposed a promising approach to improving scalability of
program synthesis by allowing the user to supply a syntactic template that
constrains the space of potential programs. Unfortunately, creating templates
often requires nontrivial effort from the user, which impedes the usability of
the synthesizer. We present a solution to this problem in the context of
recursive transformations on algebraic data-types. Our approach relies on
polymorphic synthesis constructs: a small but powerful extension to the
language of syntactic templates, which makes it possible to define a program
space in a concise and highly reusable manner, while at the same time retains
the scalability benefits of conventional templates. This approach enables
end-users to reuse predefined templates from a library for a wide variety of
problems with little effort. The paper also describes a novel optimization that
further improves the performance and scalability of the system. We evaluated
the approach on a set of benchmarks that most notably includes desugaring
functions for lambda calculus, which force the synthesizer to discover Church
encodings for pairs and boolean operations
Series voltage regulator for radial DC-microgrid
The concept of a novel series voltage regulator (SVR) for controlling the dc-bus voltage of a radial dc microgrid is presented in this paper. The proposed SVR uses a dual-active-bridge dc-dc converter followed by a full-bridge dc-dc converter. It injects dynamic voltage in series with the dc grid to compensate resistive drop over the network. As a result, the voltage level at the different points of the grid becomes independent of load variation and stays within the specified limit. Note that the required power rating of the SVR is very low (say 2.7%) compared to the load demand considering 5% voltage regulation. In this paper, the voltage regulator is connected at the midpoint of the grid, but it may be connected in some other locations to get optimal rating of the same. The proposed configuration is simulated in MATLAB/SIMULINK at a 380-V level to check the dynamic performance under various operating conditions. A scaled-down version (at 30-V level) of the proposed system is developed in the laboratory to experimentally validate the concept. The results show the effectiveness of such a voltage regulator for the radial dc microgrid, especially under critical load condition
Extended long-segment Hirschsprungs’ disease in the Waardenburg–Shah syndrome
Hypopigmentation, either a white forelock or changes in the eyebrows and/or isochromia irides, associated with signs of bowel obstruction should alert the paediatrician and paediatric surgeons to the possibility of aganglionosis. We report a case of Waardenburg–Shah syndrome, which is a very rare congenital disorder with variable clinical expression, characterized by Hirschsprungs’ disease and abnormal melanocyte migration, resulting in pigmentary abnormalities and sensorineural deafness. Our patient had an exceptional association of extended long-segment aganglionosis and underwent a proximal ileostomy but did not survive until a definitive procedure was performed. Long-term prognosis of such children is associated with high morbidity and mortality. Keywords: extended long-segment Hirschsprungs’ disease, Waardenburg–Shah Syndrome, white foreloc
R-parity violating resonant stop production at the Large Hadron Collider
We have investigated the resonant production of a stop at the Large Hadron
Collider, driven by baryon number violating interactions in supersymmetry. We
work in the framework of minimal supergravity models with the lightest
neutralino being the lightest supersymmetric particle which decays within the
detector. We look at various dilepton and trilepton final states, with or
without b-tags. A detailed background simulation is performed, and all possible
decay modes of the lighter stop are taken into account. We find that higher
stop masses are sometimes easier to probe, through the decay of the stop into
the third or fourth neutralino and their subsequent cascades. We also comment
on the detectability of such signals during the 7 TeV run, where, as expected,
only relatively light stops can be probed. Our conclusion is that the resonant
process may be probed, at both 10 and 14 TeV, with the R-parity violating
coupling {\lambda}"_{312} as low as 0.05, for a stop mass of about 1 TeV. The
possibility of distinguishing between resonant stop production and
pair-production is also discussed.Comment: 20 pages, 4 figures, 6 tables; Version accepted by JHE
Parasitic Fungi of Illinois. Part I.
Most of the plants herein described were collected in Illinois during 1881 and 1882. by Mr. A. B. Seymour, who was employed for the purpose by the Illinois State Laboratory of Natural History. The entire collection consists of three thousand seven hundred and eighty-four numbers, many of which are of course duplicates, or are different stages of the same species, leaving, however, a very large number of distinct specific forms—much larger than is usually supposed to exist in
our flora.
The determinations have been made at the Illinois Industrial University by myself, efficiently aided by Mr. Seymour. For this work, besides the facilities offered by the library and herbarium of the University, the State Laboratory of Natural History furnished many books and specimens. Among the latter are the following sets of exsiccata: DeThumen's Mycotheca Universalis, Ellis' North American Fungi. Ravenel's Fungi
Caroliniani and Fungi Americani.Ope
Naturalness and Fine Tuning in the NMSSM: Implications of Early LHC Results
We study the fine tuning in the parameter space of the semi-constrained
NMSSM, where most soft Susy breaking parameters are universal at the GUT scale.
We discuss the dependence of the fine tuning on the soft Susy breaking
parameters M_1/2 and m0, and on the Higgs masses in NMSSM specific scenarios
involving large singlet-doublet Higgs mixing or dominant Higgs-to-Higgs decays.
Whereas these latter scenarios allow a priori for considerably less fine tuning
than the constrained MSSM, the early LHC results rule out a large part of the
parameter space of the semi-constrained NMSSM corresponding to low values of
the fine tuning.Comment: 19 pages, 10 figures, bounds from Susy searches with ~1/fb include
Resonances in an external field: the 1+1 dimensional case
Using non-relativistic effective field theory in 1+1 dimensions, we
generalize Luescher's approach for resonances in the presence of an external
field. This generalized approach provides a framework to study the
infinite-volume limit of the form factor of a resonance determined in lattice
simulations.Comment: 13 pages, 2 postscript figure
Modelling of longitudinal outcomes with highly skewed distributions: applications in the IVAN trial
Yukawa unification in SO(10) with light sparticle spectrum
We investigate supersymmetric SO(10) GUT model with \mu<0. The requirements
of top-bottom-tau Yukawa unification, correct radiative electroweak symmetry
breaking and agreement with the present experimental data may be met when the
soft masses of scalars and gauginos are non-universal. We show how appropriate
non-universalities can easily be obtained in the SO(10) GUT broken to the
Standard Model. We discuss how values of BR(b-->s \gamma) and (g-2)_\mu
simultaneously in a good agreement with the experimental data can be achieved
in SO(10) model with \mu<0. In the region of the parameter space preferred by
our analysis there are two main mechanisms leading to the LSP relic abundance
consistent with the WMAP results. One is the co-annihilation with the stau and
the second is the resonant annihilation via exchange of the Z boson or the
light Higgs scalar. A very interesting feature of SO(10) models with negative
\mu is that they predict relatively light sparticle spectra. Even the heaviest
superpartners may easily have masses below 1.5 TeV in contrast to multi-TeV
particles typical for models with positive \mu.Comment: 23 pages, 5 figure
Intra‑cardiac masses in adults: A review of echocardiogram records at two echocardiographic laboratories in Enugu, South‑East Nigeria
Background: Transthoracic echocardiography (TTE) is an excellent initial diagnostic technique used to evaluate and diagnose cardiac masses, even though transoesophageal echocardiography (TEE) provides superior image resolution and better visualization of cardiac masses, especially in patients with suboptimal transthoracic echocardiographic studies. TTE is the clinical procedure of choice for identification of left ventricular thrombi. TTE has greater than 90% sensitivity and greater than 85% specificity for detection of left ventricular thrombi and is probably superior to the sensitivity and specificity of TEE, especially for apical thrombi.Aims: The study aimed to identify the common types of cardiac masses and their commonest locations in the heart.Materials and Methods: We did a retrospective review of our echocardiogram reports from May 2003 to July 2012 to identify the frequency of intra‑cardiac masses in adults, as well as the gender distribution and commonest location of these masses.Results: There were 2,814 echo examinations in adults over this period, comprising 1,661 males (59.1%) and 1,153 females (40.9%). Intra‑cardiac masses were found in 20 of these patients representing 0.7% of the study population. Thrombi were the commonest masses noted in our study, and there were more masses in the atria than in the ventricles. The left heart chambers also had more masses than the right heart chambers. There was no sex difference in the frequency of cardiac masses.Conclusion: Intra‑cardiac masses are rare, and transthoracic echocardiography is still valuable in the diagnosis and initial characterization of cardiac masses.Keywords: Adults, echocardiography, intra‑cardiac masses, NigeriaNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue
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