Enhanced near-complete absorption of electromagnetic waves by dual resonance in a magnetized plasma

There has been significant interest lately in the study of Electromagnetic (EM) waves interacting with magnetized plasmas. The variety of resonances and the existence of several pass and stop bands in the dispersion curve for different orientations of the magnetic field offer new mechanisms of EM wave energy absorption (PhysRevE.105.055209, Juneja_2023,vashistha2022localized,vashistha2020new). By an appropriate choice of inhomogeneous magnetic field, one can construct a configuration wherein the same EM wave pulse encounters more than one resonance in the plasma. A 2-D Particle - In - Cell (PIC) simulation using the OSIRIS4.0 platform has been carried out for the case of dual resonance. It is observed that in the presence of dual resonance, there is a significant enhancement in leading to almost complete absorption of laser energy by the plasma in certain cases. A detailed study of the influence of the relative location of the resonances, the effect of high input EM wave intensity, etc., has also been carried out.Comment: 11 pages, 10 figure

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

Knowledge Based Gene Set analysis (KB-GSA): A novel method for gene expression analysis

Abstract Microarray technology allows measurement of the expression levels o

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

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

Two dimensional effects of laser interacting with magnetized plasma

Recent advancements in low-frequency short-pulse $CO_2$ 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

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