arXiv subjects

Matthew Gardner

Publications and source records attributed to Matthew Gardner.

6 recordsLinked to original sources

arXiv2026

Real-World Adoption, Use, and Governance of an LLM-Based Electronic Health Record Search and Synthesis Platform

We evaluated the longitudinal adoption and use of Scout, an electronic health record-integrated large language model platform that provides cited search and synthesis of patient records, during staged deployment across a multi-hospital academic health system. Over 11 months, 2,635 users completed 80,465 tasks. 1,768 clinical users initiated use within the first 29 days of system-wide launch, which included a required training. Daily initiation increased 21.2-fold at launch, from 2.9 to 61.0 users per day. Of the 495 users who initiated use during the launch week, 310 did so in the first two days. Use spanned more than 20 recorded specialty categories, five care-practitioner roles, and 46,485 distinct prompts involving retrieval, synthesis, extraction, evaluation, and drafting, with 752 tasks saved for reuse. Among care practitioners who completed the required course, 77.9% went on to use Scout, with a median of 1.7 days after course completion. The highest-intensity user quintile accounted for 59.0% of tasks and 61.9% of tokens. Exploratory prompt analysis showed use across retrieval, synthesis, extraction, evaluation, and note-drafting. These findings suggest that rapid, broad adoption requires clinician-led task design and evaluation, traceable governance proportional to reach, centralized capacity planning and user support, and training integrated with access.

cs.CY↗

arXiv2026

Methods for Accelerating and Stabilizing Nonlinear Magnetic Equivalent-Circuit Analysis

Design and optimization of electromagnetic devices require models that converge reliably and quickly and can represent intense localized magnetic saturation. This paper presents a parameterized 2D nonlinear magnetic equivalent circuit (MEC) and proposes solution methods for it: an approximate Jacobian that is symmetric positive definite, so each Newton-Raphson iteration can use sparse Cholesky factorization with fill-reducing reordering, and Anderson mixing as step control. These methods are compared with alternative nonlinear iterations, linear solvers, and step-control methods in convergence, computational cost, and prediction accuracy. Radial-flux magnetic gears (RFMGs) with structural bridges serve as a challenging test case, because their thin bridges exhibit intense local saturation. The methods are evaluated on three bridged base designs and on 1,024 bridged designs, each paired with the same design without the bridge. On the base designs, Newton-Raphson iteration with the approximate Jacobian reached much lower residuals than fixed-point iteration, which converged for none of them. Sparse Cholesky factorization with reordering was the fastest linear solver tested. Across the 1,024 design pairs, full-step Newton-Raphson converged for 193 bridged and 564 bridge-free designs, whereas Anderson mixing converged for 1,003 and 1,022 and required fewer iterations. Bridged designs converged less often and more slowly under every method. The nonlinear MEC was 2.17 and 1.84 times faster than fixed-mesh nonlinear finite element analysis (FEA) in total computation time for the bridged and bridge-free populations. The median outer-rotor torque discrepancy relative to FEA was 0.22%, and the Spearman rank correlations of the design rankings were at least 0.9996.

eess.SY↗

arXiv2026

A Randomized Controlled Trial and Pilot of Scout: an LLM-Based EHR Search and Synthesis Platform

Clinical documentation and data retrieval within Electronic Health Records (EHRs) contribute substantially to clinician workload and burnout. To address this, we developed Scout, an LLM-based EHR search and synthesis platform that enables clinicians to query EHR data using natural language. Each response includes citations linking each claim to the original data source, facilitating easy verification of generated content. We conducted a prospective randomized, evaluator-blinded crossover trial across seven clinical specialties (20 participants, 200 structured cases). Participants completed realistic clinical tasks using either Scout or the EHR alone, with outcomes including time to completion, NASA Task Load Index workload scores, and blinded expert adjudication of accuracy, completeness, and relevance. Scout reduced task completion time by 37.6% and significantly decreased perceived workload, with the largest reductions in mental demand, effort, and temporal demand. Non-inferiority analyses showed that tasks completed with Scout maintained accuracy, completeness, and relevance relative to tasks completed with the EHR-only. A concurrent pilot deployment across over 200 users and more than 20 specialties generated over 6,600 interactions in three months, revealing diverse clinical and administrative use cases. Automated evaluation using an LLM-as-judge framework identified errors at low rates. Subsequent manual review of a subset of outputs revealed that most claims flagged by the automated judge as errors were in fact supported by the patient chart, demonstrating the importance of human validation. These findings provide early trial-based evidence that LLM-powered EHR tools can meaningfully reduce clinical and administrative workloads while maintaining output quality.

cs.IR↗

arXiv2021

Permanent Magnet Linear Generator Design for Surface Riding Wave Energy Converters

This paper describes the detailed analysis for the design of a linear generator developed for a Surface Riding Wave Energy Converter (SR-WEC), which was designed to improve energy capture over a wider range of sea states. The study starts with an analysis of the power take-off (PTO) control strategy to harness the maximum output power from given sea states. Passive, reactive, and discrete PTO control are explored. For the random wave excitation and limited sliding distance of the generator, the discrete strategy provides the highest average power output. The paper discusses the sizing requirement for the linear generator. Based on the force and power rating of the system and the application requirements, a slotless permanent magnet tubular generator is designed for the wave energy converter.

eess.SY↗

arXiv2020

Continuous data assimilation applied to a velocity-vorticity formulation of the 2D Navier-Stokes equations

We study a continuous data assimilation (CDA) algorithm for a velocity-vorticity formulation of the 2D Navier-Stokes equations in two cases: nudging applied to the velocity and vorticity, and nudging applied to the velocity only. We prove that under a typical finite element spatial discretization and backward Euler temporal discretization, application of CDA preserves the unconditional long-time stability property of the velocity-vorticity method and provides optimal long-time accuracy. These properties hold if nudging is applied only to the velocity, and if nudging is also applied to the vorticity then the optimal long-time accuracy is achieved more rapidly in time. Numerical tests illustrate the theory, and show its effectiveness on an application problem of channel flow past a flat plate.

math.NA↗

arXiv2017

The Linac Laser Notcher For The Fermilab Booster

In synchrotron machines, the beam extraction is accomplished by a combination of septa and kicker magnets which deflect the beam from an accelerator into another. Ideally the kicker field must rise/fall in between the beam bunches. However, in reality, an intentional beam-free time region (aka "notch") is created on the beam pulse to assure that the beam can be extracted with minimal losses. In the case of the Fermilab Booster, the notch is created in the ring near injection energy by the use of fast kickers which deposit the beam in a shielded collimation region within the accelerator tunnel. With increasing beam power it is desirable to create this notch at the lowest possible energy to minimize activation. The Fermilab Proton Improvement Plan (PIP) initiated an R&D project to build a laser system to create the notch within a linac beam pulse at 750 keV. This talk will describe the concept for the laser notcher and discuss our current status, commissioning results, and future plans.

physics.acc-ph↗