10,803 research outputs found
Cortisol Secreting Adrenal Adenoma in a 5 Year Old Child
Adrenal adenoma is a rare endocrinal tumor in children. It can present with features of Cushing's syndrome. We present a case report of five years old female child who came with morbid obesity and hypertension. The patient manifested polyphagia, weight gain, and changes in sleep patterns. During physical examination we found a full-moon face, bulkiness in the cervico-dorsal (buffalo-hump) region, high blood pressure
Phonon polaritonics in two-dimensional materials
Extreme confinement of electromagnetic energy by phonon polaritons holds the
promise of strong and new forms of control over the dynamics of matter. To
bring such control to the atomic-scale limit, it is important to consider
phonon polaritons in two-dimensional (2D) systems. Recent studies have pointed
out that in 2D, splitting between longitudinal and transverse optical (LO and
TO) phonons is absent at the point, even for polar materials. Does
this lack of LO--TO splitting imply the absence of a phonon polariton in polar
monolayers? Here, we derive a first-principles expression for the conductivity
of a polar monolayer specified by the wavevector-dependent LO and TO phonon
dispersions. In the long-wavelength (local) limit, we find a universal form for
the conductivity in terms of the LO phonon frequency at the point, its
lifetime, and the group velocity of the LO phonon. Our analysis reveals that
the phonon polariton of 2D is simply the LO phonon of the 2D system. For the
specific example of hexagonal boron nitride (hBN), we estimate the confinement
and propagation losses of the LO phonons, finding that high confinement and
reasonable propagation quality factors coincide in regions which may be
difficult to detect with current near-field optical microscopy techniques.
Finally, we study the interaction of external emitters with two-dimensional hBN
nanostructures, finding extreme enhancement of spontaneous emission due to
coupling with localized 2D phonon polaritons, and the possibility of multi-mode
strong and ultra-strong coupling between an external emitter and hBN phonons.
This may lead to the design of new hybrid states of electrons and phonons based
on strong coupling.Comment: 8 pages, 3 figure
Particle Swarm Optimization Framework for Low Power Testing of VLSI Circuits
Power dissipation in sequential circuits is due to increased toggling count
of Circuit under Test, which depends upon test vectors applied. If successive
test vectors sequences have more toggling nature then it is sure that toggling
rate of flip flops is higher. Higher toggling for flip flops results more power
dissipation. To overcome this problem, one method is to use GA to have test
vectors of high fault coverage in short interval, followed by Hamming distance
management on test patterns. This approach is time consuming and needs more
efforts. Another method which is purposed in this paper is a PSO based Frame
Work to optimize power dissipation. Here target is to set the entire test
vector in a frame for time period 'T', so that the frame consists of all those
vectors strings which not only provide high fault coverage but also arrange
vectors in frame to produce minimum toggling
Bilateral Filter: Graph Spectral Interpretation and Extensions
In this paper we study the bilateral filter proposed by Tomasi and Manduchi,
as a spectral domain transform defined on a weighted graph. The nodes of this
graph represent the pixels in the image and a graph signal defined on the nodes
represents the intensity values. Edge weights in the graph correspond to the
bilateral filter coefficients and hence are data adaptive. Spectrum of a graph
is defined in terms of the eigenvalues and eigenvectors of the graph Laplacian
matrix. We use this spectral interpretation to generalize the bilateral filter
and propose more flexible and application specific spectral designs of
bilateral-like filters. We show that these spectral filters can be implemented
with k-iterative bilateral filtering operations and do not require expensive
diagonalization of the Laplacian matrix
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