Research

Dall'Anese earns IEEE Best Paper Award 2023 tackling online optimization

Anonymous — Thu, 14 Dec 2023 07:00:00 +0000

Dall'Anese earns IEEE Best Paper Award 2023 tackling online optimization Anonymous (not verified) Thu, 12/14/2023 - 00:00

Charles Ferrer

How can online feedback optimization inform traffic flows for the 2028 Los Angeles Summer Olympics?

Associate Professor Emiliano Dall’Anese and his research group examined that concept for a paper that recently won the prestigious ‘Best Paper Award’ in the IEEE journal Transactions on Control of Network Systems.

The paper, “Time-Varying Optimization of LTI Systems Via Projected Primal-Dual Gradient Flows,” coauthored with Gianluca Bianchin, Jorge Cortés and Jorge Poveda, was selected for its originality, potential impact on the foundations of network systems and practical significance in applications.

“I'm very thankful to our former postdoc Gianluca and our collaborators for the time and efforts put in developing the framework presented in this paper. More broadly, I am thankful to our PhD students and collaborators that have contributed in developing theory and tools in the areas of online feedback optimization and data-driven optimization throughout the years,” said Dall’Anese. “It was definitely a team achievement.”

Dall’Anese’s research focuses on the intersection of optimization, learning and control in complex network systems. Current application domains for his research include power and energy systems and cyber-physical systems.

Applications Across Areas

“Our paper contributes positively for new tools and methods in the context of controls for complex and autonomous systems,” said Dall’Anese, “and if I were to go one step further, contributes in AI for infrastructures and cyber-physical systems.”

The mathematical framework behind this paper is centered on online feedback optimization — a topic his research group pioneered over the past 10 years. In this paper, the research group examined the Los Angeles highway system and used their framework to model traffic in hopes of lessening congestion ahead of the city’s 2028 Summer Olympics. Their outputs showed that during some parts of the day, the tools they developed significantly outperformed existing techniques.

Online feedback optimization has contributed tools in other application areas.

“Of course, the math needs to be customized, but it’s also applicable to problems in power systems, robotic systems and control of epidemics,” said Dall’Anese. “We have shown how to apply our tools in these areas such as power systems and autonomous systems in other publications.”

A Personal Accomplishment

Upon learning of this award-winning paper, the first thing Dall’Anese did was call his parents back in Italy, letting them know all their sacrifices they made in the past were being rewarded right now.

“My family struggled financially for many years,” he said. “I'm always thankful to the support that my parents provided through the years for myself and my sister.”

Some words of wisdom Dall’Anese hope to instill from this accomplishment, especially being a first-generation college student is, “anybody can be sitting here at my desk with some perseverance, hard-working and the valuable guidance of their research advisors. Anybody can make it.”

What Lies Ahead

His research group has been working on extensions of the paper’s mathematical concepts to systems in which safety needs to be prioritized — such as power grids or autonomous vehicles.

“You don’t want these vehicles to cross highway lanes. This brings together several core areas, namely optimization, machine learning and engineering,” said Dall’Anese.

In power systems, ensuring grids are tightly regulated within a given operating region is critical. Otherwise, cascading failures or disrupted service could occur without proper safety controls.

Prior to joining the �鶹ӰԺ, Dall’Anese was a senior scientist at the National Renewable Energy Laboratory creating an impact in the world of sustainable power energy systems. His latest paper is coming full circle with his research motivation.

“When looking at power and energy systems, our work’s grand goal right now is to resolve climate change issues and enable sustainability and resilience in our current power infrastructure,” Dall’Anese said.

Photo: Emiliano Dall’Anese (Credit: Jesse Peterson)

�鶹ӰԺ the IEEE Transactions on Control of Network Systems

The IEEE Transactions on Control of Network Systems publishes peer-reviewed papers at the intersection of control systems and network science. Topics covered by this journal include collaborative control, distributed learning, multi-agent systems, distributed optimization, control of collective behavior, large-scale complex systems and control with communication constraints.

Learn More �鶹ӰԺ the Award

Associate Professor Emiliano Dall’Anese and his research group examined online feedback optimization for a paper that recently won the prestigious ‘Best Paper Award’ in the IEEE journal Transactions on Control of Network Systems.

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Researchers to test Einstein's predictions of general relativity atop Rocky Mountains

Anonymous — Wed, 01 Nov 2023 06:00:00 +0000

Researchers to test Einstein's predictions of general relativity atop Rocky Mountains Anonymous (not verified) Wed, 11/01/2023 - 00:00

Charles Ferrer

Imagine being able to measure tiny changes in the flow of time caused by Earth’s gravity with atomic clocks atop one of Colorado’s iconic peaks above 14,000 feet.

That could soon be a reality thanks to a $1.9 million grant from the National Science Foundation that will advance geodesy — the study of accurately measuring Earth’s geometric shape, orientation in space and gravity field — through the use of quantum sensors, some of the most precise in the world.

Scott Diddams, professor in CU �鶹ӰԺ’s Department of Electrical, Computer and Energy Engineering (ECEE), is collaborating on this four-year, multi-agency effort with physicists from the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). To further get students involved, Diddams aims to bring undergraduate and graduate researchers in on the endeavor.

“Our vision is to take the best quantum science from the lab and translate it out to the world,” said Diddams. “It’s going to be an important activity for the university and field to show how optical clocks can impact the field of geodesy.”

Albert Einstein’s theory of general relativity states that time evolves more slowly under the influence of gravity known as the gravitational redshift. Essentially, a clock at higher elevations will tick at a faster rate than ones closer to the Earth.

Diddams and the research group are developing a portable hyper-accurate optical atomic clock, which will be the most advanced quantum sensor of time to operate at such a high elevation.

Andrew Ludlow, an adjoint professor with ECEE and the NIST physicist building the ytterbium optical clocks used in the project, noted, “if you can measure time extremely well with these atomic clocks, you can look for tiny signals that are signatures of interesting new phenomena in physics.”

“We're also constantly improving our time standards to support the measurement of evolving technologies in industry and science,” he added.

While there have been other efforts around the world to replicate similar aspects of this project, this one will take place at one of the most elevated locations in the United States - an exciting feat for the research community.

Mount Blue Sky, nestled in the Rocky Mountains of Colorado, is home to the highest paved road in North America peaking at 14,264 feet. This will allow the team to transport an optical atomic clock up the summit to measure geopotential differences corresponding to one centimeter changes in elevation.

If successful, these measurements could open up new realms of how we use quantum and atomic physics for areas in hydrology, seismology, coastal mapping and geodetic surveying.

The research team will first test these clocks at lower elevations before taking them ultimately up 14,000 feet in summer 2025.

We sat down with Professor Scott Diddams for a deep dive into the ambitious project.

What does your project entail with this new NSF grant?

Our project is really focused on using the best optical clocks — the most precise measurement tools ever made — to measure gravity. We think of the Earth as being just a sphere, but there’s actually significant variation in the Earth’s shape on large and small scales. Our plan is to use our clocks to measure those gravitational changes very precisely due to those features at different elevations.

How will you achieve this?

We're going to take one clock to the top of Mount Blue Sky and compare it to a local atomic clock in �鶹ӰԺ, Colo. This will be done via a laser link that transmits the clock’s rate over a laser beam through the air from Mount Blue Sky down to the Denver metro area. A challenge is that you don’t have a clear light of sight to �鶹ӰԺ, so we’ll have to go to a location — about 10 miles away — near the Broomfield area for that. We’ll use an optical fiber to connect from that location back to the reference clock at NIST.

This perspective provides how the mobile optical clock atop Mt. Blue Sky will communicate with the transfer node in Broomfield, Colo. and connect with a reference optical clock in �鶹ӰԺ.

What do you hope these atomic optical clocks will prove?

When we compare their rates with the two clocks, we should see the one on the top of Mount Blue Sky ticking faster. By measuring the difference in the tick rates, we hope to make the most accurate test Einstein's predictions of general relativity.

How can we relate this to everyday life?

One thing that absolutely knows gravity is water, and water will flow to the lowest gravitational potential. And so in large coastal areas, determining elevation and the flow of water at the centimeter or a few centimeters level is quite important, particularly with climate change and rising sea levels. So our project will build a connection from very fundamental quantum science to a whole new area in geodesy and surveying as we know it. This is not a topic that you would initially think is connected to quantum physics.

What makes Colorado’s Rocky Mountains uniquely fitting for this project?

We have this tremendous difference in elevation — or “relief,” in topographic terms — over a relatively short distance. There is around 9,000 feet of relief from Denver to Mount Blue Sky over a span of less than 50 miles, which we can use as leverage in the relative precision of our measurement. If we can measure the effect of that difference at the centimeter level, we stand to make the most precise measurement of the gravitational redshift. So that's pretty unique to Colorado.

What excites you about the collaboration with NIST & NOAA?

This is a very unique team, and even more so that we are all here in �鶹ӰԺ. We have world experts in all the areas that are needed to make the project successful like being able to develop portable atomic optical clocks (Andrew Ludlow) and synchronize these clocks from the top of mountains down to the city (Laura Sinclair). We’ll also have a leading expert in geodesy (Derek van Westrum) who has actually already surveyed benchmarks in our labs with millimeter-level precision.

Would you say this will be the highest altitude experiment you’ve ever conducted so far?

This probably will be the highest altitude experiment of its kind in the world. I have done short-term experiments with frequency combs on Mauna Kea in Hawaii, but that's 13,800 feet above sea level. I've never had an experiment at 14,000 feet yet, which makes this pretty unique. We're going to have to learn to efficiently work and operate the clock over extended periods in that high-altitude environment, as well.

Atomic Optical Clock Image Credit: Jesse Petersen

CU �鶹ӰԺ researchers will test general relativity atop Mt. Blue Sky and advance geodesy through the use of quantum sensors, some of the most precise in the world.

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An infrared telescope that spans the globe? New grant may make it possible

Anonymous — Mon, 25 Sep 2023 14:28:12 +0000

An infrared telescope that spans the globe? New grant may make it possible Anonymous (not verified) Mon, 09/25/2023 - 08:28

Physicists and engineers at CU �鶹ӰԺ envision infrared astronomy telescopes that may one day span the entire globe. That ambition is part of a new project led by Scott Diddams, professor in the Department of Electrical, Computer & Energy Engineering, and funded by a $1 million award from the W.M. Keck Foundation.

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CU �鶹ӰԺ earns $5 million award for 5G cellular security research

Anonymous — Fri, 22 Sep 2023 17:39:09 +0000

CU �鶹ӰԺ earns $5 million award for 5G cellular security research Anonymous (not verified) Fri, 09/22/2023 - 11:39

Two ECEE faculty members, Eric Keller and Tamara Lehman, are part of a research group leading a major military-oriented project for 5G wireless security.

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New $25-million center to advance quantum science and engineering

Anonymous — Tue, 21 Jul 2020 06:00:00 +0000

New $25-million center to advance quantum science and engineering Anonymous (not verified) Tue, 07/21/2020 - 00:00

Several ECEE faculty members will play key roles in the new Quantum Systems through Entangled Science and Engineering (Q-SEnSE) center.

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Popovic plays lead role in breakthrough light-based microprocessor chip

Anonymous — Mon, 28 Dec 2015 18:34:17 +0000

Popovic plays lead role in breakthrough light-based microprocessor chip Anonymous (not verified) Mon, 12/28/2015 - 11:34

Groundbreaking microprocessor chip uses light, rather than electricity, to transfer data at rapid speeds while consuming minute amounts of energy. The researchers also anticipate that the new technology can be integrated into current manufacturing processes smoothly and scaled up for commercial production with minimal disruption.

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Summer camp gives �鶹ӰԺ kids a taste of "Photo Origami" research

Anonymous — Wed, 12 Aug 2015 19:21:39 +0000

Summer camp gives �鶹ӰԺ kids a taste of "Photo Origami" research Anonymous (not verified) Wed, 08/12/2015 - 13:21

Shrinky Dinks used to recreate shape memory polymer research being done on the nano scale in Professor Bob McLeod's lab.

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Device delivers drugs to brain via remote control

Anonymous — Thu, 16 Jul 2015 06:00:00 +0000

Device delivers drugs to brain via remote control Anonymous (not verified) Thu, 07/16/2015 - 00:00

Jae-Woong Jeong constructs optofluidic implant that could make drug therapies more targeted with fewer side effects.

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Professor finds new health-care applications for her RF/microwave research

Anonymous — Wed, 01 Apr 2015 06:00:00 +0000

Professor finds new health-care applications for her RF/microwave research Anonymous (not verified) Wed, 04/01/2015 - 00:00

When she started getting requests to take on health care-related projects, Zoya Popovic was a little surprised. While she hadn’t pursued funding in that field, she said the projects caught her attention from a technical standpoint.

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CU-�鶹ӰԺ faculty accept Google/IEEE Little Box Challenge

Anonymous — Thu, 15 Jan 2015 07:00:00 +0000

CU-�鶹ӰԺ faculty accept Google/IEEE Little Box Challenge Anonymous (not verified) Thu, 01/15/2015 - 00:00

ECEE Assistant Professor Khurram Afridi and his team were notified by Google in December 2014 that they had received a grant to compete in the Little Box Challenge, a million-dollar prize competition funded by Google and judged by the IEEE Power Electronics Society.

The contest's goal is to dramatically change the technology of solar power inverters, and it has attracted significant attention, with 10 teams from around the world selected to receive the grant from Google.

Now, Prof. Afridi and his team has less than a year to build a power inverter that is at least 10 times smaller than the current picnic cooler-sized inverters commonly used in photovoltaic solar power systems and other green energy applications.

The 2-kVA inverter, which must fit within a 40 in3 rectangular metal enclosure, is also required to have efficiency greater than 95%, an enclosing case temperature of under 60°C without external cooling, and must conform to a number of other requirements and standards.

But Afridi isn't daunted. In fact, he says it was the demanding timeline and project requirements that piqued the team's interest in competing.

"It was aggressive enough in terms of requirements that it made for a good challenge," he said. "The power density challenge is quite aggressive, especially when you add to it other requirements like thermal management and electromagnetic interference and the fact that you're discouraged from using limited life, but high energy density, electrolytic capacitors."

Afridi also saw the challenge as a good opportunity for collaboration across disciplines. His Team Flatiron will include ECEE researchers Professor Bob Erickson, Professor Dragan Maksimovic and Dr. Dan Seltzer, as well as Associate Professor Ronggui Yang from mechanical engineering, and a number of graduate students.

While they obviously can't give away much about their approach, Afridi said they're going to use a unique energy-buffering scheme and innovative inverter topology, which should allow them to exceed the required specifications.

Because of the tight timeline, the team won't have much time for iterations. Instead, Afridi said, they will have to run all pieces of the project in parallel, which will require close collaboration.

"It basically has to be running well on the first try," he said.

In the coming July, the Team Flatiron will submit their technical approach and their little box to the judges. Eighteen finalists will then be selected to test their inverters in October at the National Renewable Energy Laboratory (NREL) in Golden, Colorado.

Because the grant from Google will only cover equipment and parts, the team will be looking for volunteer undergraduate researchers to join them in the lab. If you are interested, contact Prof. Afridi atkhurram.afridi@colorado.edu.

Afridi and his team have less than a year to build a power inverter that is at least 10 times smaller than the current picnic cooler-sized inverters commonly used in photovoltaic solar power systems and other green energy applications.

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