Measurement and Calibration of A High-Sensitivity Microwave Power Sensor with An Attenuator

In this paper, measurement and calibration of a high-sensitivity microwave power sensor through an attenuator is performed using direct comparison transfer technique. To provide reliable results, a mathematical model previously derived using signal flow graphs together with non-touching loop rule analysis for the measurement estimate (i.e. calibration factor) and its uncertainty evaluation is comparatively investigated. The investigation is carried out through the analysis of physical measurement processes, and consistent mathematical model is observed. Later, an example of Type-N (up to 18 GHz) application is used to demonstrate its calibration and measurement capability

Network calculus for parallel processing

In this note, we present preliminary results on the use of "network calculus" for parallel processing systems, specifically MapReduce

Anosmia and Ageusia as the Only Indicators of Coronavirus Disease 2019 (COVID-19)

The patient is a 60-year-old woman with a history of vertigo and seasonal allergies who presented to the hospital with the chief complaint of headache. Radiological findings were negative for intracranial abnormalities. The headache was due to trigeminal neuralgia. She had concurrent complaints of anosmia and ageusia without fever, respiratory symptoms, or obvious risk factors. However, it was determined to test the patient for coronavirus disease 2019 (COVID-19) infection despite extremely low clinical suspicion. Unfortunately, she was found to be COVID-19 positive after she was discharged from the hospital while she remained asymptomatic. There is currently a lack of published case reports describing COVID-19 patients with the sole symptoms of anosmia and ageusia in the United States of America

Diffusion in a multi-component Lattice Boltzmann Equation model

Diffusion phenomena in a multiple component lattice Boltzmann Equation (LBE) model are discussed in detail. The mass fluxes associated with different mechanical driving forces are obtained using a Chapman-Enskog analysis. This model is found to have correct diffusion behavior and the multiple diffusion coefficients are obtained analytically. The analytical results are further confirmed by numerical simulations in a few solvable limiting cases. The LBE model is established as a useful computational tool for the simulation of mass transfer in fluid systems with external forces.Comment: To appear in Aug 1 issue of PR

Iron Deficiency Anemia: An Unexpected Cause of an Acute Occipital Lobe Stroke in an Otherwise Healthy Young Woman

A 29-year-old caucasian woman who presented to the hospital with an acute onset of right eye visual disturbance and headache was found to have an acute left occipital lobe infarction. Past medical history was significant for iron deficiency anemia (IDA) secondary to menorrhagia. Her initial hemoglobin level was 7.8 G/DL, and her symptoms improved after iron and blood transfusions. Hypercoagulable studies were completed in the outpatient setting, and the results were unremarkable. Her acute stroke was most likely related to IDA as she had low cardiovascular risk factors along with a negative complete stroke workup

Lattice Boltzmann model with hierarchical interactions

We present a numerical study of the dynamics of a non-ideal fluid subject to a density-dependent pseudo-potential characterized by a hierarchy of nested attractive and repulsive interactions. It is shown that above a critical threshold of the interaction strength, the competition between stable and unstable regions results in a short-ranged disordered fluid pattern with sharp density contrasts. These disordered configurations contrast with phase-separation scenarios typically observed in binary fluids. The present results indicate that frustration can be modelled within the framework of a suitable one-body effective Boltzmann equation. The lattice implementation of such an effective Boltzmann equation may be seen as a preliminary step towards the development of complementary/alternative approaches to truly atomistic methods for the computational study of glassy dynamics.Comment: 14 pages, 5 figure

Turn-by-Turn Imaging of the Transverse Beam Profile in PEP-II

During injection or instability, the transverse profile of an individual bunch in a storage ring can change significantly in a few turns. However, most synchrotron-light imaging techniques are not designed for this time scale. We have developed a novel diagnostic that enhances the utility of a fast gated camera by adding, inexpensively, some features of a dual-axis streak camera, in order to watch the turn-by-turn evolution of the transverse profile, in both x and y. The beam's elliptical profile is reshaped using cylindrical lenses to form a tall and narrow ellipse—essentially the projection of the full ellipse onto one transverse axis. We do this projection twice, by splitting the beam into two paths at different heights, and rotating the ellipse by 90° on one path. A rapidly rotating mirror scans these vertical “pencils” of light horizontally across the photocathode of the camera, which is gated for 3 ns on every Nth ring turn. A single readout of the camera captures 100 images, looking like a stroboscopic photograph of a moving object. We have observed the capture of injected charge into a bunch and the rapid change of beam size at the onset of a fast instability

Completely monotone and Bernstein functions with convexity properties on their measures

The concepts of completely monotone and Bernstein functions have been introduced near one hundred years ago. They find wide applications in areas ranging from stochastic L\\u27{e}vy processes and complex analysis to monotone operator theory. They have well-known Bernstein and L\\u27{e}vy-Khintchine integral representations through which there are one-to-one correspondences between them and Radon measures on $[0,\infty)$ or $(0,\infty)$, respectively. In this thesis, we investigate subclasses of completely monotone and Bernstein functions with various convexity properties on their measures. These subclasses have intriguing applications in probability theories and convex analysis. The convexity properties we investigate include convexity, harmonic convexity and $\beta$-convexity of the cumulative distribution functions. We characterize measures with various convexity properties to obtain results analogous to the classical P\\u27{o}lya\u27s Theorem. Then we apply these characterizations of the measures to derive integral representations for these classes of completely monotone and Bernstein functions that are variants of the classical Bernstein and L\\u27{e}vy-Khintchine integral representations. To explore the connections among completely monotone and Bernstein functions with various convexity properties on their measures, we investigate the characterizations and obtain various necessary and sufficient conditions for a completely monotone or Bernstein function to belong to one of the subclasses. We also identify maps that transform completely monotone and Bernstein functions into one with certain convexity properties on their measures. Interesting parallels between completely monotone and Bernstein functions are observed. For example, the transformation that turn a Bernstein function into one having L\\u27{e}vy measure with harmonically concave tail is the same as the transformation that turns a completely monotone function into one having harmonically convex measure. To help understand these analogies, a criteria for completely monotone and Bernstein function to have measures with $\beta$-convexity property is obtained.That generalizes the conditions for both convexity and harmonic convexity. Let $\mathcal{H}_{CM}$ be the set of all Bernstein functions $h$, such that $f\circ h$ is the Laplace transform of a harmonically convex measure for {\it any} completely monotone function $f$. Similarly, let $\mathcal{H}_{BF}$ be the set of all Bernstein functions $h$, such that $g\circ h$ has L\\u27{e}vy measure with harmonically concave tail for {\it any} Bernstein function $g$. Surprisingly, we show that $\mathcal{H}_{CM} = \mathcal{H}_{BF}$ and are non-empty. For example we prove that $x^\alpha$ is in $\mathcal{H}_{BF}$ for any $\alpha \in (0, {2}/{3}]$. In other words, the Bernstein function $x \mapsto x^\alpha$ is a transformation that deforms the measure of any Bernstein (resp. completely monotone) function into one that not only has a continuous distribution function on $(0,\infty)$ but also a convenient concavity (reps. convexity) property. We give necessary and sufficient condition for a Bernstein function to be in $\mathcal{H}_{BF}$ in terms of its convolution semigroups of sub-probability measures. However, it is not well-understood what are the functions that ``generate\u27\u27 this set. We hope to investigate such issues in the future