Category: Graduate Programs
Telecommunications companies – those that allow us to talk on the phone, communicate over the Internet and watch cable television – used to operate under the notion that there was an infinite amount of fiber bandwidth available to transmit these signals. Then we moved into the Y2K era.
“There was a big explosion of data around the year 2000,” said Larry A. Coldren, the Fred Kavli Professor of Optoelectronics and Sensors at the University of California, Santa Barbara. “Computers were also getting faster and faster at this time and the demand for bandwidth was rising quickly.”
Coldren and his team had started looking at photonic integrated circuits (PICs), devices that allow signals to travel on optical waves on semiconductor chips, back in the 1980s and discovered that they could viably be produced much like analogous electronic integrated circuits (ICs) that generally use electrical wires for transferring data.
Last month, he spoke about his research during Boston University’s Electrical & Computer Engineering Distinguished Lecture Series. He suggested that PICs could be the key component in the future of telecommunications.
Just a couple of decades ago, wavelength-division multiplexing (WDM) was introduced to meet the demand for more fiber bandwidth. This method allowed a number of signals to be simultaneously transferred on a single optical fiber. However, at the terminals where the WDM channels must be either combined or separated, the optical and electronic equipment became more and more complex as the channel count and signal speed increased. That’s where Coldren’s research comes into play.
“PICs have the potential of improved performance, reliability and cost while also reducing the size, weight and power of the equipment,” said Coldren.
PICs for various applications have been made using indium phosphide, silica on silicon, polymer technologies, and silicon photonics. Electronic ICs, however, usually use silicon as a dominant ingredient. Coldren’s team currently focuses on a monolithic indium phosphide integration platform.
“Ultimately, we may find that the best results will come from a hybrid solution using more than one of these materials,” said Coldren.
Today, PICs are widely deployed commercially and outperform many discrete device approaches, but Coldren is optimistic that they can work even better in the future and hopefully result in more environmentally friendly supercomputers and data centers.
“Our efforts have always been focused on making PICs very efficient and very fast,” said Coldren. “Now we need to look at how they can be used to create more green data centers.”
Assistant Professor Jonathan Klamkin (ECE), who introduced Coldren at the lecture, previously had an opportunity to study with Coldren while earning his Ph.D. at UC Santa Barbara.
“I benefitted immensely from his guidance and even use his books in my class here,” Klamkin said. “It’s a pleasure having him on our campus.”
Prior to teaching, Coldren worked at Bell Labs, where he studied surface-acoustic-wave signal processing devices and tunable coupled-cavity lasers. He continued his work at UC Santa Barbara, where he has developed more widely-tunable DBR lasers and efficient, high-speed vertical-cavity-surface-emitting lasers (VCSELs) in addition to his PIC research.
Coldren is a member of the National Academy of Engineering and a Fellow of the Institute of Electrical and Electronics Engineers (IEEE), the Optical Society (OSA) and the Institution of Electrical Engineers (IEE).
Coldren’s talk was the third in the three-part Fall 2013 Distinguished Lecture Series. The seminars will resume in Spring 2014.
-Rachel Harrington (email@example.com)
Over the last few weeks, nearly 20 million Americans tried accessing a broken United States health care site that couldn’t handle the traffic, among other problems. And even if you weren’t one of the many applying for health coverage, you’ve probably experienced network congestion at some point.
Typically, network congestion occurs if a link or node is carrying too much data; as a result, the quality of service drops. The most severe form of communication disruption is deadlocks. A deadlock happens when several messages mutually block each other so that their delivery is not just delayed but stopped permanently.
“This is a long-standing problem, which is practically important and theoretically challenging,” said Distinguished Professor Lev Levitin (ECE, SE). “It has been attracting the efforts of many researchers for decades.”
Professors Levitin and Mark Karpovsky (ECE) have been working with their students on this problem for several years, developing new algorithms, specifically turn prohibition algorithms, to help direct data and essentially prevent information from being stuck in a deadlock as it travels through communication networks. This work covered a lot of ground by establishing lower and upper bounds for an optimal solution, outlining their discovery of a new class of algorithms, and developing a few algorithms that could actually solve the initial optimization problem.
The last advance on this project was achieved this year by Levitin and his team – ECE alum, Ye Wu (MEng ’13), and Visiting Scholar, Mehmet Mustafa. They have been working on developing new algorithms, specifically turn prohibition algorithms, to help direct data and essentially prevent information from being stuck in a deadlock as it travels through communication networks.
“Without changing the topology of existing networks, we managed to improve saturation points so that congestion is less likely to happen and latency is reduced which means lower waiting time for users,” said Wu.
The team recently presented their work at OPNETWORK 2013, a conference that focused on advancing the state of application and network performance management. Impressed by their research, “A Study of Modified Turn Prohibition Algorithms for Deadlock Prevention in Networks,” the judges awarded them Best Technical Paper.
“Computer experiments, executed earlier and in the latest work by Ye Wu and other students under the guidance of Dr. Mustafa, clearly showed the superior performance of our algorithms versus different algorithms suggested by other research groups,” said Levitin. He went on to add that the majority of publications in the field are on ad hoc algorithms as opposed to the “tree-free” algorithms he and his team explored.
The work gave Wu a chance to travel to Washington, D.C., and deliver the presentation at the Ronald Reagan Building and International Trade Center.
“I met some really nice students and professors from different countries who were happy to talk about their research,” said Wu. “The audience, I think, was also smart enough to understand the key points of our project and asked really good questions.”
Now a Boston University graduate, Wu looks back at his professor fondly, describing Levitin as open-minded, even when his student was questioning his own theories.
“Professor Levitin is the best professor I’ve ever known,” said Wu. “Even when we had no idea how to begin a project, he’d point us in the right direction.”
-Rachel Harrington (firstname.lastname@example.org)
NSF Research Program Helps ENG Vets Shape Careers
US military personnel return from active duty with highly marketable knowledge and skills, but many find it difficult to quickly parlay their experience into well-paying jobs. To help rectify the situation, the National Science Foundation (NSF) funds the Veteran’s Research Supplement (VRS) program, which allows veterans at selected colleges and universities to participate in industrially relevant research in science, technology, engineering, and mathematics (STEM) — fields in which job openings far outpace the supply of qualified US applicants.
Since the inception of VRS in 2011, the College of Engineering’s NSF Industry/University Collaborative Research Center for Biophotonic Sensors & Systems has welcomed the opportunity to engage veterans in research through this program.
“Vets come to us with an unusually strong work ethic and high confidence but often lack the experience to be comfortable in taking on a big research project,” said BU Photonics Center Director and Professor Thomas Bifano (ME, MSE). “VRS gives them the opportunity to take on such projects and pursue careers in research, which is the main engine of our economy.”
So far two veterans have thrived in faculty-supervised summer projects funded by VRS, emerging not only with new research skills but also a more well-defined career path.
Cliff Chan: From Technician to Engineer
Cliff Chan, who deployed four times in the Middle East and Southeast Asia as an Air Force Guidance and Control Specialist, came to BU seeking to take his skillset to the next level. With a B.S. in mathematics and computer science from the University of California, San Diego, two years developing software for an electronic health records company, and four years maintaining aircraft control systems for the Air Force under his belt, Chan aspired to learn how to design the kinds of technologies he came across during his military service.
To transform himself from a technician to an engineer, he sought a way to earn a master’s degree in electrical engineering in a reasonable timeframe without having to start from scratch, and he found it in the College of Engineering’s Late Entry Accelerated Program (LEAP). Like all LEAP students, Chan spent his first year taking undergraduate engineering courses to get up to speed, but got his first taste of engineering design the following summer (2011), thanks to the VRS program. Working for three months in Professor Jerome Mertz’s (BME) Biomicroscopy Lab within BU’s Center for Biophotonic Sensors and Systems, he developed software that enables microscopes to provide high-contrast images of biological samples in real time.
“The project was a real transition for me, as I had to solve a problem by first figuring out what I needed to learn, and then how to apply it,” recalled Chan, who was used to getting more explicit instructions in the Air Force and had never worked in a research lab. “It opened up my eyes to another world.”
Subsequently hired to work full-time in the Biomicroscopy Lab while completing his Master of Engineering in electrical engineering, Chan has continued to advance microscopy techniques aimed at improving medical diagnostic imaging. The experience has led him to consider working in research and development for defense and other industries, conducting experiments and designing devices with real-world applications.
It has also prepared him to work through the inevitable unexpected challenges that arise in advancing new technologies.
“What I like about Cliff is that he’s undaunted,” said Mertz. “He wants to learn everything that’s out there to tackle his work. The problems we faced were much more complex than I had anticipated, but Cliff’s efforts definitely kept us on track, and kept us progressing.”
Chris Stockbridge: From Defusing Roadside Bombs to Protecting Future Soldiers
Chris Stockbridge returned to civilian life after five years as an officer and combat engineer in the Army that included two tours of duty in Iraq. During each deployment he came to appreciate the engineering behind technologies used to protect soldiers, including devices used to search for and destroy roadside bombs. Equipped with those experiences and a B.S. in mechanical engineering from the US Military Academy at West Point, he applied to the PhD program in mechanical engineering at BU with the goal of working as a civilian engineer at a national military research lab.
“I came to BU to study micro-electro-mechanical systems (MEMS), particularly those which could be of great value in military applications, and because I knew that the Photonics Center has a strong relationship with the US Army Research Laboratory,” said Stockbridge.
Supported last summer by the VRS program to serve as the lead student in an NSF-funded project in Bifano’s Precision Optics Research Lab, he began fabricating MEMS for a new deformable mirror design for use in the Keck and other very large telescopes. Aimed at supplying the telescopes with mirrors that have more pixels for finer imaging control, his work could enable astronomers to make observations that shed light on the origin of the universe and the existence of life on extra-solar planets.
“The primary benefit to me from this project was spending more time doing hands-on MEMS fabrication work,” said Stockbridge, who had already spent two years working on the design of deformable mirrors in Bifano’s lab. “While I would prefer to work more in design after graduation, the hands-on skills are important for getting an appreciation of each process step that goes into building a MEMS mirror.”
As he has cultivated those skills, Stockbridge has proven to be an invaluable asset in Bifano’s lab.
“Chris is a consummate engineer who seems to thrive on tackling problems that are both thorny and hard, and I can see in his work the experience and training that he gained while serving in the Army,” said Bifano. “He is a natural collaborator, and all of the other students in my lab and in the labs of my close colleagues have come to rely on him for his strong sense of mechanical design and for his eagerness to help those around him. Chris will make a great professional engineer.”
-Rachel Harrington (email@example.com)
Each day, we find ourselves sharing our personal information across the internet – whether it’s to pay a bill or buy a gift on Amazon.
As we send more of our data through these channels, there is a growing concern about privacy. Earlier this month, a breach at Adobe, for example, impacted more than 38 million users. Cases like this are not uncommon and as a result, cyber security has become a major area of research for electrical and computer engineers.
Last week, Professor George J. Pappas, the Chair of the Department of Electrical and Systems Engineering at the University of Pennsylvania, visited Boston University and shared his own work on the topic.
Pappas is looking at how differential privacy, a method that aims to maximize the accuracy of information extracted from databases while also minimizing the chance of records being identified, can be applied to systems like smart grids and intelligent transportation systems.
“Privacy breaches are generally due to side information that a company collects,” Pappas explained. He believes that by using a differentially private mechanism to transfer information, it’ll be possible to hide secure data.
“You’re trying to hide in the noise and make it hard to know who’s who,” he said.
Pappas believes that one of the greatest challenges is figuring out how to give companies like Google and eBay the information they need without the sensitive data they don’t.
An advantage of differential privacy, he said, is that once you indicate a particular segment of information is private, it stays private even after the data is sent to another system. Pappas believes that by adding noise during the streaming process, secure information can be blocked. The trick is figuring out how much noise should be added.
Pappas is a Fellow of IEEE and has received several awards including the Antonio Ruberti Young Research Prize, the George S. Axelby Award, and the National Science Foundation PECASE. In addition to differential privacy, his research focuses on control theory and, in particular, hybrid systems, embedded systems, hierarchical and distributed control systems, with application to unmanned aerial vehicles, distributed robotics, green buildings, and biomolecular networks.
Pappas’s talk was the second in the three-part Fall 2013 Distinguished Lecture Series. The next talk will feature Professor Larry A. Coldren, University of California, Santa Barbara, who will speak on the topic, “Photonic Integrated Circuits as Key Enablers for Coherent Sensor and Communication Systems.” Hear him on Wednesday, November 20, at 4 p.m. in PHO 211.
-Rachel Harrington (firstname.lastname@example.org)
New Laser Technique Boosts Accuracy of DNA Sequencing Method
Low-cost, ultra-fast DNA sequencing would revolutionize healthcare and biomedical research, sparking major advances in drug development, preventative medicine and personalized medicine. By gaining access to the entire sequence of your genome, a physician could determine the probability that you’ll develop a specific genetic disease or tolerate selected medications. In pursuit of that goal, Associate Professor Amit Meller (BME, MSE) has spent much of the past decade spearheading a method that uses solid state nanopores — two-to-five-nanometer-wide holes in silicon chips that read DNA strands as they pass through — to optically sequence the four nucleotides (A, C, G, T) encoding each DNA molecule.
Now Meller and a team of researchers at Boston University — Professor Theodore Moustakas (ECE, MSE) and research assistants Nicolas Di Fiori (Physics, PhD ’13) and Allison Squires (BME, PhD ’14) — and Technion-Israel Institute of Technology — have discovered a simple way to improve the sensitivity, accuracy and speed of the method, making it an even more viable option for DNA sequencing or characterization of small proteins.
In the November 3 online edition of Nature Nanotechnology, the team demonstrated that focusing a low-power, commercially available green laser on a nanopore increases current near walls of the pore, which is immersed in salt water. As the current increases, it sweeps the salt water along with it in the opposite direction of incoming samples. The onrushing water, in turn, acts as a brake, slowing down the passage of DNA through the pore. As a result, nanoscale sensors in the pore can get a higher-resolution read of each nucleotide as it crosses the pore, and identify small proteins in their native state that could not previously be detected.
“The light-induced phenomenon that we describe in this paper can be used to switch on and off the ‘brakes’ acting on individual biopolymers, such as DNA or proteins sliding through the nanopores, in real time,” Meller explained. “This critically enhances the sensing resolution of solid-state nanopores and can be easily integrated in future nanopore-based DNA sequencing and protein detection technologies.”
Slowing down DNA is essential to DNA or RNA sequencing with nanopores, so that nanoscale sensors, like sports referees, can make the right call on what’s passing through.
“The goal is to hold a base pair of DNA nucleotides in the nanopore’s sensing volume long enough to ‘call the base’ (i.e, determine if it’s an A, C, G or T),” said Squires, who fabricated nanopores and ran experiments in the study. “The signal needs to be sufficiently different for each base for sensors in the nanopore to make the call. If the sample proceeds through the sensing volume too quickly, it’s hard for the sensors to interpret the signal and make the right call.”
Other methods designed to slow down DNA in nanopores change the sensing properties of the pore, making it more difficult to ensure accuracy of detected base pairs. Shining laser light on the nanopore alters only the local surface charge, an effect that’s completely reversible within milliseconds by switching the laser off.
As an added bonus, the researchers found that the sudden increase in surface charge and resulting flow of water reliably unblocks clogged nanopores, which can take a long time to clean, significantly extending their lifetime.
Meller and his team characterized the amount of increase in current under varying illumination in many different-sized nanopores. They next aim to explore in greater detail the mechanism underlying the increase in surface current when the green laser is applied to a nanopore, information that could lead to even more sensitivity and accuracy in DNA sequencing.
The research is funded by a $4.2 million grant from the National Institute of Health’s National Human Genome Research Institute under its “Revolutionary Sequencing Technology Development — $1,000 Genome” program, which seeks to reduce the cost of sequencing a human genome to $1,000.
Imagining intelligent traffic lights, parking spaces, buildings and appliances
Last year, the Daily Beast named Boston the country’s smartest metropolitan area. The website was referring to the people of Boston, of course, not the city itself. But what if the city itself were smart? What if technology, designed by the smart people who work in Boston, could help us save time and energy and spare us from daily frustrations? We talked to some BU researchers who are studying, designing, and building the technology for a more enlightened city.
Because the cost of electricity fluctuates throughout the day, depending on demand, smart meters that are currently available tell homeowners exactly how much energy they use and at what cost, encouraging them to delay energy-intensive activities until a time of day when demand and costs are low. Supported by a $2 million National Science Foundation grant, Professor Michael Caramanis (ME, SE), Professor John Baillieul (ME, SE) and two MIT faculty members are collaborating on a study of how these and larger-scale measures could result in a smarter electricity grid. In the United States, we lose about 8 percent of energy because it travels long distances between points of generation to use. Caramanis thinks the loss could be greatly reduced if we got our energy from closer and cleaner sources. A smarter grid could help us do that.
Security officers could sort through billions of hours of video footage and spot unusual events, such as someone attempting to enter a building in the middle of the night, using specially designed cameras with embedded algorithms. Professor Janusz Konrad (ECE) and Venkatesh Saligrama (ECE, SE) have developed the technology, supported by more than $800,000 in funding from the National Science Foundation, the Department of Homeland Security, and other agencies.
BU engineers have designed software that, once uploaded to a building’s HVAC system, would measure airflow room by room and revise it to meet minimum standards, decreasing energy costs while keeping occupants happy. The invention earned Associate Professor Michael Gevelber (ME, SE), Adjunct Research Professor Donald Wroblewski (ME) and ENG and School of Management students first prize and $20,000 in this year’s MIT Clean Energy Competition. The team plans to develop and market the software through its newly formed company, Aeolus Building Efficiency.
Smarter Traffic Lights
A smart traffic lighting system would mine GPS information from cars and smartphones and count the number of vehicles waiting at red lights. If there is no approaching traffic, it would switch lights from red to green. Professor Christos Cassandras (ECE, SE) is testing this system on a model mini-city in his lab.
Cassandras, working with research assistant Yanfeng Geng (PhD, SE ’13), has developed the BU Smart Parking application, which can be downloaded to a smartphone from the iPhone App Store by searching “BU smartparking.” Drivers tell the app when and where they want to park, prioritizing price and location, and the app searches for available spaces, all of which are networked to the device. When the app identifies a spot that meets the search criteria, it tells the driver where to go. At the same time, a light installed above the spot turns from green to red. When the driver who made the reservations approaches, the light turns yellow. The catch? At the moment the system works only in BU’s 730 Commonwealth Avenue garage, but Cassandras hopes to expand it to private parking facilities throughout Boston.
The next-generation lightbulb could enhance sleep quality, send data like a Wi-Fi hotspot does, or help visitors navigate large buildings through a network of visible cues, while operating more efficiently. This technology is made possible by combining LEDs, sensors, and other control systems within a single hybrid bulb that needs 40 to 70 percent less energy than existing compact fluorescent lights or LED lightbulbs. It is being developed by Professor Thomas Little (ECE, SE), associate director of the Smart Lighting Engineering Research Center, working with researchers at the center under an $18.5 million National Science Foundation grant. Little is collaborating with colleagues from Rensselaer Polytechnic Institute and the University of New Mexico.
Refrigerators and hot water heaters are duty-cycle appliances, meaning they need to run only two to three times each hour. Caramanis thinks they could be designed to communicate with the electricity grid and run when electrical demand is lowest during that time period. Alternatively, if either of these appliances is connected to a home photovoltaic unit, it could be programmed to detect when a passing cloud blocks the sun and choose to cycle at a later time. Caramanis says this technology is mostly being tested in pilot settings. A New Jersey-based company called FirstEnergy has installed temperature sensors and communication controllers that turn on and off the hot water heaters of thousands of consumers in relation to low or high energy costs in the Pennsylvania, New Jersey, and Maryland region.
Smarter Central Control
Imagine a network of sensors that would collect and send data to a centralized processor, which could order a garbage pickup or warn drivers of traffic jams. Cassandras, Professor Yannis Paschalidis (ECE, SE), codirector of the Center for Information & Systems Engineering, and Professor Assaf Kfoury (CS), are testing a miniature version of this network in Cassandras’ lab, with help from a $1 million grant from the National Science Foundation.
-Leslie Friday (Videos by Joe Chan), BU Today
Ahmed (Magdy) Farouk (MS ’12) may be a recent graduate, but that hasn’t kept him from having big ideas about how to improve solar energy efficiency.
Just a few months ago, he was on stage at MIT’s Future Energy event, pitching his idea about new structures of organic solar cells that increase the light harvesting capabilities of these devices, as well as reduce their costs by eliminating many of their expensive components and making them more manufacturable.
Farouk’s plan involves using organic semiconductors that can be dissolved into a solvent and treated as ink. He then takes the ink and puts it in a printer to produce a drawing – on virtually any substrate – of a solar cell with all of its components. He said that by using this method with the new structure, solar energy could produce cheaper electricity than fossil fuels.
At the April 4 MIT event, Farouk introduced his proposal to a room full of investors, researchers, and other entrepreneurs. At Future Energy, about 100 start-ups focused on solving the world’s energy challenges present in front of an audience and a panel of four experts and investors. Only eight new projects, including Farouk’s, advanced to the finals, during which each team presented and took questions from a panel of judges.
Farouk decided to participate in Future Energy because of the collaborative platform the event provides. “For me, the real benefits were the exposure and the interaction with other entrepreneurs and experts in this community,” he explained. “It helped me understand more what investors are looking for, what their main concerns are, and how I can improve my business model.”
Farouk presented similar research during his master’s presentation at BU, but pitching the idea was different for Future Energy. The presentation needed to be more business-oriented rather than technically-detailed because investors were examining the economical viability of the idea.
“To be able to estimate the economical data requires a different kind of research that sometimes is even more demanding than the technical side,” Farouk stated.
Farouk said that in the past, the solar manufacturing industry has been volatile. Many solar companies failed because they raised more funds than they actually needed. Currently, many investors are hesitant to lend out funds.
Learning from his experience at the Future Energy event, Magdy is working on making his design technologically ready and creating a preliminary prototype. He believes he needs stronger proof to garner more investor interest, and he is eager to build upon his work based on what he learned during the competition.
- Chelsea Hermond (SMG ’15)
Top-Tier Faculty to Advance High-Impact Field
Synthetic biology brings together engineers, biologists and other life science researchers to conceive, design and build molecular biological systems that rewire and reprogram organisms to perform specified tasks. The field promises not only to yield new insights into biology but also to spark new technologies that could revolutionize healthcare, energy and the environment, food production, materials and global security. Recognizing the wide-ranging potential of synthetic biology and the trailblazing efforts of many of its faculty, the College of Engineering has launched the BU Center of Synthetic Biology (CoSBi) to advance this emerging discipline.
Poised to take a nationally preeminent role in advancing synthetic biology research, CoSBi unites core engineering faculty members that bridge diverse research interests, including microbial and metabolic engineering, immuno-engineering, cell reprogramming, computer-aided design and automation, single-cell analyses and systems modeling. In addition, the center involves leading researchers across the university with expertise in systems biology, leveraging their ability to reverse-engineer natural biological networks to help in the modeling, design and forward-engineering of synthetic biological networks with novel functions.
“We envision that CoSBI will serve as a focal point for activities in synthetic biology at Boston University and the larger Boston area, and help to advance the field toward applications in biomedical research, healthcare and other areas,” said Professor James J. Collins (BME, MSE, SE), one of the pioneers of synthetic biology, who directs the center.
CoSBi is located at 36 Cummington Mall, taking advantage of the newly renovated wet and dry facilities on the second floor and computational space on the third floor. Core faculty include Collins; Assistant Professor Ahmad “Mo” Khalil (BME), the center’s associate director; Assistant Professor Douglas Densmore (ECE, BME, Bioinformatics); and Assistant Professor Wilson Wong (BME), with 11 associate faculty members drawn from the College of Engineering, College of Arts & Sciences, and School of Medicine.
To advance its research agenda, CoSBi is expected to attract substantial government funding, major industrial collaborators and top-notch graduate students and postdoctoral fellows. The center will develop and support large-scale, collaborative projects, organize an annual symposium on synthetic biology featuring prominent researchers from around the world, and host a regular seminar series showcasing research leaders in the field.
To enable students of all levels to learn about the fundamentals and practice of synthetic biology and explore their interests in the intersection of engineering and molecular biology, the center will play an active role in supporting research training, education and outreach activities. Center administrators aim to appoint new research faculty and staff; develop new fellowships for and facilitate mentoring of graduate students and postdoctoral associates; design new courses and produce educational videos; run international synthetic biology competition teams and summer workshops; and build community for undergraduate, graduate and postdoctoral students studying synthetic biology.
“Synthetic biology is reshaping the discipline of biology, and attracting students and researchers with a diverse set of backgrounds,” said Khalil. “A central goal of CoSBi will be to prepare the next generation of synthetic biologists for this multidisciplinary type of research at an early stage, and to challenge them to think conceptually and creatively about how engineering can help in understanding life.”
New Algorithms Could Cut Costs, Add Renewables
When power transmission lines reach their capacity in a particular region during high demand periods, controllers have little choice but to tap local power plants to keep the electricity flowing and prevent blackouts. This practice, which favors expensive, local generation sources such as coal and natural gas over cheaper, typically more remote, renewable sources such as wind farms and solar arrays, adds an estimated $5 billion to $10 billion per year to the cost of running the US power grid. As more and more renewable generation sources join the grid and increase transmission line congestion, that price is expected to rise substantially.
To mitigate this cost, College of Engineering researchers and collaborators at Tufts University and Northeastern University have a plan that could enable controllers to exploit cheaper, renewable generation sources when transmission lines become congested. Supported by a $1.2 million grant from the Department of Energy’s Advanced Research Programs Agency (ARPA-E) in 2012 and an additional $1 million as of September, the researchers are developing algorithms and software that can produce short-term changes in the power transmission network that redistribute power across the network and utilize renewable sources without overloading transmission lines.
They estimate that the algorithms they’re developing will save $3 billion to $7 billion annually and significantly improve the resilience of today’s power transmission network. Based on a fundamental law of physics dictating that electric current is distributed along the paths of least resistance, the algorithms are designed to discover, in real time, preferred reconfigurations of the transmission network.
“By removing a small number of critical transmission lines, you change the relative resistances across alternative network paths, and electric power redistributes itself, relieving the congestion,” said Professor Michael Caramanis (ME, SE), the project’s co-principal investigator along with Research Associate Professor Pablo Ruiz (ME), who is leading the research effort. “If you disconnect the right lines, you can relieve congestion, increase use of inexpensive power sources and lower congestion costs.”
Having already implemented their algorithms in reproducing real-life situations in collaboration with the PJM transmission system, the largest power market in the US covering many eastern states, the researchers – with the recent addition of Professor Yannis Paschalidis (ECE, SE) – are now fine-tuning their software. Their immediate goal is to provide new ways of integrating wind generation with lower costs while strengthening the power transmission network. But to achieve that goal entails wrestling with a lot of computational complexity. Out of tens of thousands of transmission lines, the software must select a few, perhaps four or five, whose connection or disconnection will minimize the “spilling” or waste of inexpensive wind generation that might occur during high-congestion periods.
“Based on our understanding of power markets, in which prices can vary every five minutes at each node of the network, we can infer which lines would be beneficial to disconnect and which not,” said Caramanis. “When we disconnect a line, we also know how it will change the power flow over every other line, and how much we will gain by relieving the transmission network capacity a little bit. The idea is to optimize the network to reduce costly congestion.”
Over the next two-and-a-half years, the team plans to continue refining its algorithms in collaboration with PJM, two software companies and an energy consulting firm. It will also design tests and procedures to ensure that the dynamic reconfiguration of the transmission network causes no disruption in the security and stability of the power system. If the software is adopted across PJM or other vast transmission networks, controllers seeking to relieve congestion will have the capability to connect and disconnect selected transmission lines every half hour or hour as needed, rather than once or twice a month, as they do now – or even automate the process.
Crane was recently named a recipient of a Clare Boothe Luce Scholarship, given for two academic years to advanced degree candidates. Each fellowship covers the cost of tuition, medical insurance, mandatory fees, a $20,000 stipend and $4,000 for allowance to cover educational and professional development expenses.
The Clare Boothe Luce Program (CBL), the largest source of private funding for women in science, mathematics, and engineering, aims to increase women’s participation in science and engineering at every level of higher education.
Given the recent honor, it’s hard to believe that Crane, who earned her master’s degree through the Late Entry Accelerated Program (LEAP), only began studying engineering three years ago after graduating with an English degree summa cum laude from Clark University.
“I was unsure how long it would take to fulfill the many course requirements, as I was coming in with virtually none of them completed,” said Crane. “I dove in headfirst though and often overloaded on courses to finish in a timely fashion.”
Crane said that earning her master’s in a short timeframe motivated her to apply for her doctorate at BU.
“I didn’t even apply anywhere else,” she said. “There is tremendous value in students having familiarity with the faculty and vice versa, and in having an established rapport with a doctoral advisor right at the outset of research. There is no other school in the world where I would have had that advantage.”
At BU, Crane has been working closely with her advisor, Professor Hamid Nawab (ECE), who nominated her for the award.
“Molly is precisely the type of person who would help to further shatter the glass ceiling in the male-dominated world of electrical engineering research and academia,” said Nawab. “I wouldn’t be surprised if she wound up becoming a tenured faculty member in a leading ECE department or an internationally renowned leader in her field.”
Crane said she was taken by surprise when she won the award, especially since she had a very non-traditional path into engineering.
“The foundation’s support has allowed me to move into a coveted realm in doctoral research, where the student is free to define the problem on which her research will focus without having to worry about focusing solely on a problem as defined in a grant,” said Crane.
Crane’s research at BU focuses on signal processing, though her work overlaps into other areas.
“We’re at the point now where artificial intelligence is really exploding, and fields like signal processing are interwoven in that explosion,” said Crane.
Crane said that she hopes her work will help improve the ability of artificial intelligence (AI) applications to work in the face of mutually interfering inputs.
Examples of such AI applications include Apple’s Siri or Google’s voice recognition. Both work if a user is speaking clearly into a microphone, but if there are signals like music or other voices superimposed on the input speech signal, the results are often inaccurate.
She hopes to find a way to extract the meaningful input even when interfering signals are in the way, and do so in a way that can be applied to multiple applications.
“I’m looking forward to the opportunity to do research on a problem that has far-reaching implications and the potential to contribute something meaningful to the signal processing community at large,” she said.
Crane has been thrilled with her BU experience, describing her professors as “accessible and brilliant.”
“I am happy to be at BU, to call Boston home, and am looking forward to the experiences ahead,” said Crane. “Honestly, I’ve never been happier.”
-Rachel Harrington (email@example.com)