Covey, Lehe, Mendis, Saxton-Fox, Stinville, and Tessum win NSF CAREER awards
The 6 GCOE faculty received NSF’s “most prestigious” early-career awards
In recent weeks, the National Science Foundation announced that six of its most recent CAREER awards were won by members of the GCOE faculty: Jacob P. Covey, Lewis Lehe, Charith Mendis, Theresa Saxton-Fox, Jean-Charles Stinville, and Christopher Tessum.
According to NSF’s website, Faculty Early Career Development (CAREER) grants are its “most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.”
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Covey is an assistant professor in the Department of Physics. Under his award, entitled “Operating an Optical Atomic Clock Beyond the Laser Coherence and Below the Projection Limit,” he will work to improve the atomic systems that form the basis of atomic clocks.
Atomic clocks based on optical transitions have emerged as the most accurate metrological tool ever developed. In fact, they are so precise that they would lose less than one second across the entire age of the universe. Current research seeks to further improve their precision and to deploy them outside of state-of-the-art laboratories. Both goals require more efficient use of the atomic resources that drive the clocks.
Covey will use quantum information science tools to optimize the atomic system. Using the ability to operate and measure subsets of the atomic array independently, he will encode two atomic clocks within one system and use one to stabilize the other. In addition, he will use quantum entanglement to improve the clock precision by mitigating what physicists call “quantum projection noise.”
He will combine those approaches to realize an atomic clock that helps stabilize the more precise entangled atomic clock, thereby providing near-optimal use of atomic resources.
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Lehe is an assistant professor in the Department of Civil & Environmental Engineering. Under his award, entitled “The Choice of Free vs. Priced for Transportation Systems,” he will study issues related to pricing of public transportation services and facilities, such as parking and transit.
In the project, he will extend models of road and transit systems to account for considerations that arise when prices are added or removed, such as the differences in bus boarding times with and without fares. To capture policy impacts across sociodemographic groups and income levels, the project will create simulations calibrated to represent real communities.
“Scholars have focused on choosing ‘optimal’ prices for transportation facilities, but often the big question that cities debate is whether to charge at all,” Lehe explained. “This CAREER grant will allow my research to evolve in a new direction, bringing my background in theory to bear on the practical concerns of local policymakers.”
Lehe’s team will also conduct surveys to understand people’s attitudes towards alternative pricing strategies, and will illuminate how people think about the fairness of transportation pricing.
The ultimate purpose of the work is to better inform policy choices on whether to charge prices for transportation services.
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Mendis is an assistant professor in the Department of Computer Science. With his CAREER grant, entitled “An Agile Compiler Framework for Spatial Dataflow Accelerators,” he will invent a way to generate compilers for AI accelerators automatically via synergistic use of machine learning and formal methods.
AI accelerators are small machines that are assembled in large numbers to handle machine learning tasks by doing matrix multiplications quickly and with great energy efficiency. Many companies have been developing them; Google’s Tensor Processing Units (TPUs) and Amazon’s Inferentia and Trainium are examples.
But there’s a catch: “Each company is developing their own compiler by hand, and there does not exist a compiler infrastructure that works across many different accelerators,” says Mendis. “How do you build compiler technologies easily, that can adapt to multiple accelerators?”
His answer is to use machine learning and formal methods synergistically, such that compilers are constructed automatically with little manual intervention by humans. In addition to enormous cost savings, a big advantage of his solution will be the ease of revising compilers quickly.
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Saxton-Fox is an assistant professor in the Department of Aerospace Engineering. Under her award, entitled “Turbulence in a Rapidly Changing World,” she will advance understanding of the acceleration and deceleration of “boundary layer flows”—flows of air or water near the surface of moving vehicles.
Significant work has been done on boundary layer flows for large vehicles under constant wind conditions, and for small vehicles during unsteady maneuvers—but not on boundary layer flows for large vehicles under unsteady conditions. Understanding such flows can help in predicting and controlling the motion of vehicles that are big enough to carry people.
“We will consider accelerations and decelerations in space, as one would expect for a flow moving over a curved surface, and accelerations and decelerations in time, as one would expect for a vehicle executing a maneuver or operating in gusty conditions,” explained Saxton-Fox.
She said that others have studied accelerating turbulent boundary layers, especially as they accelerate past a curving shape, but they have considered only a single shape, or only a few constant rates of acceleration.
“We’ll take a different approach, leveraging modern measurement technologies and novel experiments to systematically study how changing a key parameter affects the turbulent response,” she said.
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Stinville is an assistant professor in the Department of Materials Science & Engineering and the Materials Research Lab. Under his CAREER award, entitled “Leveraging Plastic Deformation Mechanisms’ Interactions in Metallic Materials to Access Extraordinary Fatigue Strength,” he will pursue a fundamental understanding of how materials deform at extreme temperatures, and will seek ways to modify existing metallic materials so they resist fatigue.
More specifically, he is looking for ways to “pre-deform” materials under extremely low or high temperatures to put them into states in which they are less susceptible to subsequent deformation caused by repeated loading, very high or low temperatures, or thermal cycling.
Stinville believes that “a dual focus on both high and cryogenic temperatures is necessary in metals to address new technological developments related to energy, transportation, and space applications.”
His ultimate goal is to find solutions that will allow metallic structures to last for a very long time despite having to endure such extreme conditions.
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Tessum is an assistant professor in the Department of Civil & Environmental Engineering. Under his CAREER award, entitled “Air-quality-related Environmental Justice Impacts of Decarbonization Scenarios,” he will develop a new modeling framework for assessing the climate, air quality, and environmental equity impacts of various decarbonization policy scenarios, and he will apply the framework in the analysis and evaluation of climate policy.
“The U.S. and other nations are at the beginning of a major technological shift from a fossil fuel-based economy to one driven by non-climate-forcing energy generation,” Tessum said. “The speed and success of this technology shift... depend in part upon whether it is perceived to be implemented equitably with benefits that accrue broadly across society.”
The open-source computational tools to be created will facilitate the calculation of air quality benefits and related equity. The goal is to identify the advantages and disadvantages of various decarbonization policy scenarios. The project will also target improved understanding of effective methods for educating the general public on climate science and policy.