173 research outputs found
Attitudes Towards Vaccination Among Medical Students: A Two-Site Study
Introduction:
Mandatory immunization for school age children in the 20th Century led to a substantial decline in infectious disease.
All US states allow medical exemptions from immunizations with 49 permitting additional religious exemptions and 19 permitting additional philosophical exemptions.
Vaccine exemptions have lead to an increase in the incidence of disease outbreaks.
Healthcare providers play a critical role in educating parents about the benefits and risks of immunizations.
This project compares student attitudes and knowledge regarding vaccination at medical schools in two distinct states: one with no additional exemptions (West Virginia) and one with both additional exemptions (Vermont).https://scholarworks.uvm.edu/comphp_gallery/1218/thumbnail.jp
Signal optimization at isolated intersections using pre-signals
This research proposes a new signal operation strategy aimed at efficient utilization of
green time by cutting down on the start up and response loss times. The idea is to have a
"pre-signal" on each main approach a few hundred feet upstream of the intersection in
addition to the main intersection signal, which is coordinated with the pre-signal. The
offset between the main and pre-signal ensures that the majority of start up losses does
not occur at the main signal. The benefits of the system under various traffic conditions
were evaluated based on analysis of the queue discharge process and Corridor
Simulation (CORSIM) study. The proposed measure should reduce the travel time and
total control delay for the signalized network.
To attain the objective the following two studies were undertaken:
1. Development of a queue discharge model to investigate the expected benefits of
the system.
2. Simulation of the system: In the second part of the research, the proposed
strategy was tested using CORSIM to evaluate its performance vis-à-vis the
baseline case.
The queue discharge model (QDM) was found to be linear in nature in contrast to prior
expectations. The model was used to quantify the benefits obtained from the pre-signal
system. The result of this analysis indicated that the proposed strategy would yield
significant travel time savings and reductions in total control delay. In addition to the QDM analysis, CORSIM simulations were used to code various
hypothetical scenarios to test the concept under various constraints and limitations. As
per expectations, it was found that the system was beneficial for high demand levels and
longer offsets. The upper limit on offsets was determined by visual observation of
platoon dispersion and therefore the maximum offset distance was restricted to 450 feet.
For scenarios where split phasing was used, the break even point in terms of demand
level was found to be 2500 vph on a three lane approach, whereas that for a lag-lag type
of phasing strategy was found to be 1800 vph, also on a three lane approach
Harmonic generation in magnetized plasma for Electromagnetic wave propagating parallel to external magnetic field
The harmonic generation has always been of fundamental interest in studying
the nonlinear nature of any physical system. In the present study, Particle -
In - Cell (PIC) simulations have been carried out to explore the harmonic
generation of Electromagnetic waves in a magnetized plasma. The EM wave
propagation is chosen to be parallel to the applied external magnetic field.
The simulations show the excitation of odd higher harmonics of RCP (Right
circularly polarized) and LCP (Left circularly polarized) when the incident
wave is linearly polarised. The harmonic generation is maximum when the
incident EM wave frequency matches the electron cyclotron frequency. When the
incident EM wave has a circular polarization, no harmonics get excited. A
theoretical understanding of these observations has also been provided. The
studies thus show that by appropriately tailoring of plasma parameters EM waves
of higher frequencies and desired nature of circular polarization can be
generated.Comment: 25 pages, 15 figure
Knowledge Based Gene Set analysis (KB-GSA): A novel method for gene expression analysis
Abstract Microarray technology allows measurement of the expression levels o
HALO: Post-Link Heap-Layout Optimisation
Today, general-purpose memory allocators dominate the landscape of dynamic memory management. While these so- lutions can provide reasonably good behaviour across a wide range of workloads, it is an unfortunate reality that their behaviour for any particular workload can be highly suboptimal. By catering primarily to average and worst-case usage patterns, these allocators deny programs the advantages of domain-specific optimisations, and thus may inadvertently place data in a manner that hinders performance, generating unnecessary cache misses and load stalls.
To help alleviate these issues, we propose HALO: a post-link profile-guided optimisation tool that can improve the layout of heap data to reduce cache misses automatically. Profiling the target binary to understand how allocations made in different contexts are related, we specialise memory-management routines to allocate groups of related objects from separate pools to increase their spatial locality. Unlike other solutions of its kind, HALO employs novel grouping and identification algorithms which allow it to create tight-knit allocation groups using the entire call stack and to identify these efficiently at runtime. Evaluation of HALO on contemporary out-of-order hardware demonstrates speedups of up to 28% over jemalloc, out-performing a state-of-the-art data placement technique from the literature
SMILE: Scaling Mixture-of-Experts with Efficient Bi-level Routing
The mixture of Expert (MoE) parallelism is a recent advancement that scales
up the model size with constant computational cost. MoE selects different sets
of parameters (i.e., experts) for each incoming token, resulting in a
sparsely-activated model. Despite several successful applications of MoE, its
training efficiency degrades significantly as the number of experts increases.
The routing stage in MoE relies on the efficiency of the All2All communication
collective, which suffers from network congestion and has poor scalability. To
mitigate these issues, we introduce SMILE, which exploits heterogeneous network
bandwidth and splits a single-step routing into bi-level routing. Our
experimental results show that the proposed method obtains a 2.5x speedup over
Switch Transformer in terms of pretraining throughput on the Colossal Clean
Crawled Corpus without losing any convergence speed
Two dimensional effects of laser interacting with magnetized plasma
Recent advancements in low-frequency short-pulse lasers and the
production of strong magnetic fields have made experimental studies on laser
interactions with magnetized plasma a near-future possibility. Therefore,
theoretical and numerical simulation studies have been pursued lately in this
direction [A. Das, Review of Modern Plasma Physics 4, 1 (2020)] illustrating a
host of novel phenomena related to laser energy absorption [Vashistha et al.,
New Journal of Physics, 22(6):063023 (2020); Goswami et al., Plasma Physics and
Controlled Fusion 63, 115003 (2021)], harmonic generation [Maity et al.,
Journal of Plasma Physics, 87(5) (2021)], etc. However, most of these studies
have been carried out in one-dimensional geometry with the laser having
infinite transverse extent, and the plasma target was considered cold. This
manuscript explores the manifestation of the 2-D and thermal effects on the
problem of a laser interacting with magnetized plasma. As expected, additional
transverse ponderomotive force is shown to be operative. A finite temperature
of the target, along with transverse density stratification generates, leads to
diamagnetic drift for the two plasma species. The imbalance of this drift
between the two species can be an additional effect leading to an enhancement
of laser energy absorption. The Particle - In - Cell (PIC) simulations with the
OSIRIS4.0 platform is used to explore these features.Comment: 15 pages, 12 figures, 12 equation
Ion heating in Laser interacting with magnetized plasma
The ion heating mechanism in the context of laser interacting with plasma
immersed in a strong magnetic field is studied. The magnetic field is chosen to
be strong for laser electromagnetic field propagation inside the plasma to be
governed by the magnetized dispersion relation. Both X and RL mode
configurations have been studied in detail using Particle - In - Cell (PIC)
simulations. It is shown that the energy absorption process is governed by a
resonant mechanism wherein the laser frequency matches with an underlying mode
in the plasma. For X and RL mode configurations, these correspond to lower
hybrid and ion cyclotron resonance, respectively. The absorption, however, is
found to be most efficient at frequencies close to but not exactly matching
with the resonance frequency. An understanding of the same has been provided.
The role of laser polarization has been studied in detail.Comment: 21 pages, 17 figure
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