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University of Wisconsin–Madison

New faculty

Focus on new faculty: Po-Ling Loh, applying abstract math to real-world situations

po-ling-loh-copy-825wDecember 1, 2016

A new assistant professor in the University of Wisconsin-Madison Department of Electrical and Computer Engineering uses highly conceptual calculations to tackle concrete problems like medical imaging or modeling how diseases spread.

Po-Ling Loh, who joined the faculty in fall 2016 and is also a fellow at the Grainger Institute for Engineering, arrives at Madison with a strong background in theoretical statistics, honed and refined during her graduate studies and two years as an assistant professor at Pennsylvania University. Her deep affection for advanced analytics extends all the way back to her early education.

“At the beginning of undergrad, I loved math, especially abstraction. I just thought it was really cool. But now I feel like it’s good to have applications to the real world,” says Loh.

Some of those applications include reconstructing accurate images from medical scans. Loh is looking forward to collaborating with researchers in the medical school to help doctors improve their diagnoses based on fewer measurements.

“I’m exciting about engaging with people here. I have some colleagues in ECE who have been talking to people in radiology. I think that would be a good place for me to plug in,” says Loh.

Her interest in health also extends to global problems, such as how infections take hold and potentially become epidemics. Because multiple random interacting processes determine how pathogens proliferate, describing diseases with accurate mathematical models is no simple task.

“We’re learning that you can dream up a model, but once you start talking to someone in the field, you realize that your model needs to be adjusted. Maybe you don’t have the full information that you thought you did in the mathematical world,” says Loh.

Bridging the gap between the conceptually clean mathematical world and the messy circumstances on planet earth can be challenging, but that practical ethos motivates Loh to both pursue engineering research and educate future engineers about the power of math.

“I’m teaching the undergraduate probability and stochastic processes class. The students are interested in the math not just as an end in itself, but so that they can apply it to real world problems, whether they’re going to be working in communications systems or building devices,” says Loh.

Allowing students to pursue their own passions is a central principle of her mentoring philosophy. She relishes opportunities to work on new problems based on the questions raised by her students. That research relationship is partly what set Loh down the path of mathematically modeling disease epidemics, after her trainee became interested in HIV spreading in Africa.

Loh’s enthusiasm to explore new ideas has her seeking out collaborations across campus. She plans to work with Varun Jog, who also joined the ECE faculty at the beginning of fall semester in 2016. They bring a complementary skillset to the department.

“Varun and I have started collaborating. His interest is also very mathematical and we both like working together. We’re thinking about problems that bring in both of our strengths,” says Loh.

Joining the faculty at UW-Madison represents something of a homecoming for Loh, who grew up on Madison’s west side. After spending time away in California and on the East Coast for her education, Loh is thrilled to be back among the friendly citizens of the City on Four Lakes.

“My favorite thing about Madison is the people,” she says. “People here are genuinely nice in a way that would seem really weird if you were in another state.”

Author: Samuel Million-Weaver

Focus on new faculty: Xin Wang, untying knotty systems

Xin Wang1 (1).jpg

Where others see hopelessly foundering logistics, Xin Wang sees the possibility of creating sustainable and resilient systems for things like developing biofuels and keeping cities operating when disaster strikes.

Wang, assistant professor of industrial and systems engineering and an affiliate of the new Grainger Institute for Engineering, brings an interdisciplinary approach to solving these large-scale problems.

“This is a very exciting opportunity,” says Wang. “My focus and background is interdisciplinary. I plan to collaborate with colleagues in the Grainger Institute, those in industrial engineering and other departments.”

When Wang was a doctoral student at the University of Illinois at Urbana-Champaign, his research—mainly funded by the National Science Foundation—honed in on the creation of biofuels, which is wrought with competing factors and uncertainty.

For example, Wang developed mathematical models to examine ways in which the government can better design policies to answer challenging questions in the development of corn-based and other cellulosic biofuels, such as how to maintain food security and develop new energy sources in ways that are environmentally sustainable.

“Our framework can be applied successfully to solve issues when there are competition, reliability and interdependence issues,” he says.

To validate his research, Wang employed a multi-user, web-based simulation game in which players assumed the roles of various stakeholders who make individual decisions on use of farmland, biofuel investments and government mandates and subsidies.

“This software can help us collect data that simulates reality, and help show how various decisions by stakeholders affect the entire system,” Wang says. “We have to consider not only the economic impact, but the social and environmental impacts. That will help develop the biofuel industry in a sustainable way.”

Wang says the model can be applied to a variety of complex systems, such as infrastructure or manufacturing systems. Recently, Wang began working with the U.S. Army Corps of Engineers to use the mathematical model to analyze the reliability of urban systems.

Specifically, Wang researches how the government plans to protect critical urban infrastructure. He hopes the research will help the government evaluate adverse impacts and enhance preparedness and reliability of key urban systems.

During a natural or man-made disaster, Wang says events may cascade—causing a potentially disastrous effect. Some of the effects hit the physical infrastructure and some affect the supply of resources.

For example, a power outage could cause electricity-dependent water systems to shut down. In turn, people might travel to seek water, pinching fuel supplies and resulting in gridlocked traffic.

“When you consider the problem at first, it may not seem complicated, but when you factor in people’s behavior, it can become significant and disaster could happen,” Wang says. “If the disruption caused by people’s behavior is at a critical infrastructure, it may amplify the disruption.”

The research will help the government know the social impact of infrastructure breakdowns and respond accordingly.

“We hope to tell, based on the infrastructure disruption, what is the social impact? Then the government can have an idea about the reliability of a city and which infrastructure is the most critical to protect,” Wang says.

Inherent in Wang’s research is a depth of knowledge in logistics systems and supply chain management, key components in advanced manufacturing, one of the focuses of the Grainger Institute. The institute, created in 2014 with a $25 million gift from The Grainger Foundation, serves as an incubator for transdisciplinary research.

“Advanced manufacturing is not only using the innovative technology to improve production,” says Wang. “But it also needs to use successful management methodologies to enhance supply chain efficiency and reduce supply uncertainty or energy usage and environmental impact.”