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Search Publications by: Lucas Koepke (Fed)

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Displaying 1 - 6 of 6

Evaluation of 3D Curvature and Lead Stress of Transvenous Right Ventricular Leads: The Human Use Conditions Study (HUCS)

September 9, 2023
Author(s)
Jonathan Piccini, Tim Quinn, Lucas Koepke, James Dawson, Nicki Mara, Jason Santelli, Diane Muff, Jordan Savela, Alex Felber, Michael Friedrich, Jens Rump, Felix Tschentscher, Jake Benzing, Charles Swerdlow
Transvenous leads of cardiac implanted electronic device (CIED) systems are meant to last the life of the patient, but they are at risk for conductor fatigue fracture from applied alternating stress. This stress depends on lead design and use conditions

Effects of as-built surface with varying number of contour passes on high-cycle fatigue behavior of additively manufactured nickel alloy 718

August 5, 2023
Author(s)
Orion Kafka, Jake Benzing, Nicholas Derimow, Philipp Schumacher, Lucas Koepke, Chad Beamer, Donald Godfrey, Nik Hrabe
High cycle fatigue life of laser-powder bed fusion (L-PBF) parts depends on several factors; as-built surfaces, when present, are a particular concern. This work measures as-built L-PBF surfaces with X-ray computed tomography, and uses rotating beam

Characterizing LTE User Equipment Emissions Under Closed-Loop Power Control

April 6, 2021
Author(s)
Jason Coder, Aric Sanders, Michael R. Frey, Adam Wunderlich, Azizollah Kord, Jolene Splett, Lucas N. Koepke, Daniel Kuester, Duncan McGillivray, John M. Ladbury
This report presents a laboratory-based characterization of Long Term Evolution (LTE) User Equipment (UE) emissions under closed-loop power control, building on our prior work (NIST TN 2069), which assessed the impact of a large number of factors affecting

Multiple Changepoint Analysis of Noisy Nonlinear Data with an Application to Modeling Crack Growth in Additively Manufactured Titanium

December 5, 2019
Author(s)
Lucas N. Koepke, Jolene D. Splett, Timothy P. Quinn, Nikolas W. Hrabe, Jake T. Benzing, Michael R. Frey
Noisy measurement data pose a challenge for changepoint analysis, especially in the presence of multiple changepoints and when the model is nonlinear. We explore various approaches to estimating changepoints and their standard errors under these conditions

Characterizing LTE User Equipment Emissions: Factor Screening

September 30, 2019
Author(s)
Jason Coder, Adam Wunderlich, Michael R. Frey, Paul T. Blanchard, Dan Kuester, Azizollah Kord, Max Lees, Aric Sanders, Jolene Splett, Lucas N. Koepke, Rob Horansky, Duncan McGillivray, John M. Ladbury, Jeffrey T. Correia, Venkatesh Ramaswamy, Jerediah Fevold, Shawn Lefebre, Jacob K. Johnson, John Carpenter, Mark Lofquist, Keith Hartley, Melissa Midzor
Characterizations of long-term evolution (LTE) user equipment (UE) emissions are a key ingredient in models of interference between wireless cellular networks and other systems that must use the same radio frequency spectrum. This report presents (i) a