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Recent Progress in Vertical Gallium Nitride Power Devices

Kaplar, Robert J.; Allerman, Andrew A.; Crawford, Mary H.; Gunning, Brendan P.; Flicker, Jack D.; Armstrong, Andrew A.; Yates, Luke; Dickerson, Jeramy; Binder, Andrew T.; Abate, Vincent M.; Smith, Michael L.; Pickrell, Gregory W.; Sharps, Paul; Neely, Jason C.; Rashkin, Lee J.; Gill, Lee; Goodrick, Kyle; Anderson, T.; Gallagher, J.; Jacobs, A.G.; Koehler, A.; Tadjer, M.; Hobart, K.; Hite, J.; Ebrish, M.; Porter, M.; Zeng, K.; Chowdhury, S.; Ji, D.; Aktas, O.; Cooper, James A.

Abstract not provided.

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TYPE Conference Presentation YEAR 2021
DOIOSTI

ASMT-783246, Assessment Report for Department 635 Analysis of Fiscal Year 2021 ES&H Events

Morgans-Harrer, Kathleen

This assessment analyzes Environment, Safety, and Health (ES&H) occurrences and Non-Occurrence Trackable Events (NOTEs) from fiscal year (FY) 2021. For this report, assessors used three primary methods for categorizing occurrence and NOTE data: issue categorization, DOE reporting criteria groups, and DOE cause codes. The FY 2021 Q1 occurrence and NOTE total was the lowest since this type of analysis began in FY 2018 Q4, following a downward trend from the FY 2019 Q3 high point. The FY 2021 Q2 occurrence and NOTE total was nearly double the FY 2021 Q1 total; occurrence totals declined slightly in Q3 and Q4, while NOTE totals remained the same. NOTEs in each of the final three quarters were more than double the amount from Q1. This assessment resulted in one observation. As COVID-19 vaccination rates increase and COVID 19 impacts on operations decrease, the number of workers on-site and the amount of activity-level work will increase. With these changes, focused attention on the following areas related to work planning and controls may reduce the probability of future events, hazard identification and analysis, compliance with standards, formality of operations, and job scoping.

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TYPE Other Report YEAR 2021
DOIOSTI

Credible, Automated Meshing of Images (CAMI)

Roberts, Scott A.; Donohoe, Brendan D.; Martinez, Carianne; Krygier, Michael; Hernandez-Sanchez, Bernadette A.; Foster, Collin W.; Collins, Lincoln; Greene, Benjamin; Noble, David R.; Norris, Chance; Potter, Kevin M.; Roberts, Christine; Neal, Kyle D.; Bernard, Sylvain R.; Schroeder, Benjamin B.; Trembacki, Bradley; Labonte, Tyler; Sharma, Krish; Ganter, Tyler; Jones, Jessica E.; Smith, Matthew D.

Abstract not provided.

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TYPE Presentation YEAR 2021
OSTI

Estimating the Adequacy of a Multi-Objective Optimization

Waddell, Lucas; Gauthier, John H.; Hoffman, Matthew J.; Bays, Nathan R.; Henry, Stephen M.; Dessanti, Alexander; Pierson, Adam J.

Multi-objective optimization methods can be criticized for lacking a statistically valid measure of the quality and representativeness of a solution. This stance is especially relevant to metaheuristic optimization approaches but can also apply to other methods that typically might only report a small representative subset of a Pareto frontier. Here we present a method to address this deficiency based on random sampling of a solution space to determine, with a specified level of confidence, the fraction of the solution space that is surpassed by an optimization. The Superiority of Multi-Objective Optimization to Random Sampling, or SMORS method, can evaluate quality and representativeness using dominance or other measures, e.g., a spacing measure for high-dimensional spaces. SMORS has been tested in a combinatorial optimization context using a genetic algorithm but could be useful for other optimization methods.

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TYPE SAND Report YEAR 2021
DOIOSTI

Quantitative assessment of Distributed Acoustic Sensing at the Source Physics Experiment, Phase II

Porritt, Robert W.; Abbott, Robert; Poppeliers, Christian

In this report, we assess the data recorded by a Distributed Acoustic Sensing (DAS) cable deployed during the Source Physics Experiment, Phase II (DAG) in comparison with the data recorded by nearby 4.5-Hz geophones. DAS is a novel recording method with unprecedented spatial resolution, but there are significant concerns around the data fidelity as the technology is ramped up to more common usage. Here we run a series of tests to quantify the similarity between DAS data and more conventional data and investigate cases where the higher spatial resolution of the DAS can provide new insights into the wavefield. These tests include 1D modeling with seismic refraction and bootstrap uncertainties, assessing the amplitude spectra with distance from the source, measuring the frequency dependent inter-station coherency, estimating time-dependent phase velocity with beamforming and semblance, and measuring the cross-correlation between the geophone and the particle velocity inferred from the DAS. In most cases, we find high similarity between the two datasets, but the higher spatial resolution of the DAS provides increased details and methods of estimating uncertainty.

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TYPE SAND Report YEAR 2021
DOIOSTI
Results 11351–11400 of 101,000
Results 11351–11400 of 101,000
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