Publications
Operation of an optical atomic clock with a Brillouin laser subsystem
Summary
Summary
Microwave atomic clocks have traditionally served as the 'gold standard' for precision measurements of time and frequency. However, over the past decade, optical atomic clocks have surpassed the precision of their microwave counterparts by two orders of magnitude or more. Extant optical clocks occupy volumes of more than one cubic...
Ultrasound diagnosis of COVID-19: robustness and explainability
Summary
Summary
Diagnosis of COVID-19 at point of care is vital to the containment of the global pandemic. Point of care ultrasound (POCUS) provides rapid imagery of lungs to detect COVID-19 in patients in a repeatable and cost effective way. Previous work has used public datasets of POCUS videos to train an...
A multi-task LSTM framework for improved early sepsis prediction
Summary
Summary
Early detection for sepsis, a high-mortality clinical condition, is important for improving patient outcomes. The performance of conventional deep learning methods degrades quickly as predictions are made several hours prior to the clinical definition. We adopt recurrent neural networks (RNNs) to improve early prediction of the onset of sepsis using...
Towards a distributed framework for multi-agent reinforcement learning research
Summary
Summary
Some of the most important publications in deep reinforcement learning over the last few years have been fueled by access to massive amounts of computation through large scale distributed systems. The success of these approaches in achieving human-expert level performance on several complex video-game environments has motivated further exploration into...
A hardware root-of-trust design for low-power SoC edge devices
Summary
Summary
In this work, we introduce a hardware root-of-trust architecture for low-power edge devices. An accelerator-based SoC design that includes the hardware root-of-trust architecture is developed. An example application for the device is presented. We examine attacks based on physical access given the significant threat they pose to unattended edge systems...
Fast training of deep neural networks robust to adversarial perturbations
Summary
Summary
Deep neural networks are capable of training fast and generalizing well within many domains. Despite their promising performance, deep networks have shown sensitivities to perturbations of their inputs (e.g., adversarial examples) and their learned feature representations are often difficult to interpret, raising concerns about their true capability and trustworthiness. Recent...
Human balance models optimized using a large-scale, parallel architecture with applications to mild traumatic brain injury
Summary
Summary
Static and dynamic balance are frequently disrupted through brain injuries. The impairment can be complex and for mild traumatic brain injury (mTBI) can be undetectable by standard clinical tests. Therefore, neurologically relevant modeling approaches are needed for detection and inference of mechanisms of injury. The current work presents models of...
Sensorimotor conflict tests in an immersive virtual environment reveal subclinical impairments in mild traumatic brain injury
Summary
Summary
Current clinical tests lack the sensitivity needed for detecting subtle balance impairments associated with mild traumatic brain injury (mTBI). Patient-reported symptoms can be significant and have a huge impact on daily life, but impairments may remain undetected or poorly quantified using clinical measures. Our central hypothesis was that provocative sensorimotor...
Antennas and RF components designed with graded index composite materials
Summary
Summary
Antennas and RF components in general, can greatly benefit with the recent development of low-loss 3D print graded index materials. The additional degrees of freedom provided by graded index materials can result in the design of antennas and other RF components with superior performance than currently available designs based on...
Graded index dielectric superstrate for phased array scan compensation
Summary
Summary
This paper presents the use of additively manufactured graded index materials to improve the scan impedance variation of phased arrays. Solvent-based extrusion permits the programmatically controlled printing of chosen material properties with relative permittivity ranging from 2 to 24.5. This low-loss material shows promise for improvement of scan impedance variation...