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Among Virginia Tech graduates celebrating their achievements today include four Ph.D. and five master’s students at the Discovery Analytics Center.

Four Ph.D. students and one master’s student plan to complete degrees during the summer.

“The thoughtful and impactful research our students have engaged in while pursuing their graduate degrees has been recognized by many major academic conferences and is testament to their hard work,” said Naren Ramakrishnan, the Thomas L. Phillips Professor of Engineering and director of the center.

“We are always very proud of our graduates but especially so this year as they have had to persevere through some very unusual circumstances to achieve their goals,” Ramakrishnan said. “We wish them continued success as they venture into new career challenges at universities, research laboratories, and businesses.”

Ph.D. Spring graduates

Bijaya Adhikari, advised by B. Aditya Prakash, is receiving a Ph.D. in computer science. His research interests are data science and machine learning for large networks and data driven epidemiology. The title of his dissertation is “Domain-based Frameworks and Embeddings for Dynamics over Networks.” Adhikari is joining the Department of Computer Science at the University of Iowa in the fall as a tenure track assistant professor.

Tyler Chang, advised by Layne Watson, is receiving a Ph.D. in computer science. His research interests are numerical approximation, optimization, algorithms, parallel computing, data science, and scientific computing. The title of his dissertation is “Mathematical Software for Multi-objective Optimization Problems.” Chang is joining the Mathematics and Computer Science Division at Argonne National Laboratory in Chicago, Illinois. Specifically, he will work in the Laboratory for Applied Mathematics, Numerical Software, and Statistics as a postdoctoral appointee, a group he previously interned with.

Michelle Dowling, advised by Chris North and Mike Horning, is receiving a Ph.D. in computer science. She is also receiving a graduate certificate in urban computing, a National Science Foundation-sponsored program administered through DAC. Dowling’s research interests are human-computer interaction, data analytics, information visualization, and interactive data visualization. The title of her dissertation is “Semantic Interaction for Symmetrical Analysis and Automated Foraging of Documents and Terms.” Dowling is joining Grand Valley State University, her alma mater, as an assistant professor.

Mohammad Raihanul Islam, advised by Naren Ramakrishnan, is receiving a Ph.D. in computer science. His research interests are social network/media analysis, deep learning, and graph neural network. The title of his dissertation is “Detecting and Mitigating Rumors in Social Media.”  Islam is joining Amazon, Inc., as an applied scientist. 

Liuqing Li, advised by Edward Fox, is receiving a Ph.D. in computer science. His research interests are digital library, social analysis, machine learning, and deep learning. The title of his dissertation is “Event-related Collections Understanding and Services.” Li is joining Yahoo! as a research scientist.

Master’s Spring Graduates

Arjun Choudhry, advised by Naren Ramakrishnan, is receiving a master’s degree in computer science.  His research interests are narrative generation, blockchain technologies. His thesis is titled “The Art of Simplifying Graph Interpretation: Narrative Generation Using Causal Exploration of Directed Graphs.” Choudhry is joining Amazon, Seattle, as a software development engineer.

Jeffrey McCullen, advised by Chandan Reddy, received a master’s degree in computer science. His research interests are machine learning and data analytics in healthcare, and software engineering.  The title of his thesis is “Predicting the Effects of Sedative Infusion on Acute Traumatic Brain Injury Patients.”

Joseph Messou, advised by Jia-Bin Huang, is receiving a master’s degree in computer engineering. His research interests are computer vision and machine learning, efficient training methods for networks, and cybersecurity. The title of his thesis is “Handling Invalid Pixels in Convolutional Neural Networks.”  In the fall, Messou will be a Ph.D. student in computer engineering at the University of Maryland, College Park.

Shih-Yang Su, advised by Jia-Bin Huang, is receiving a master’s degree in computer engineering. His research interests are machine perception, visual representation learning, and reinforcement learning. His thesis is titled “Learning to Handle Occlusion for Motion Analysis and View Synthesis.” In the fall, Su will be a Ph.D. student in computer science at the University of British Columbia, where his research will focus on learning and understanding human motion for motion synthesis and character animations.

Ming Wang, advised by Chris North, is receiving a master’s degree in computer science. Her research interests are visual analytics and information visualization. Her thesis is titled “Bridging Cognitive Gaps Between User and Model in Interactive Dimension Reduction.” Wang is joining Salesforce as a software engineer.

Summer Ph.D. graduates

Zhiqian (Danny) Chen, advised by Chang-Tien Lu, will complete his Ph.D. in computer science. Chen’s research interests are graph mining, urban computing, network science. The title of his dissertation is “Graph Neural Networks: Techniques and Applications.” Chen will join the Computer Science and Engineering Department at Mississippi State University as assistant professor.

Tianyi Li, advised by Chris North, will complete her Ph.D. in computer science. Her research interests include developing systems for computer-supported cooperative work and devising visual analytics tools with user-centered design to combine and coordinate human and artificial intelligence in broader, real-world sensemaking processes. Her dissertation is titled “Solving Mysteries with Crowds: Supporting Crowdsourced Sensemaking with a Modularized Pipeline and Context Slices.”  Li will be joining Loyola University in Chicago as assistant professor.

Thomas Lux, advised by Layne Watson, will complete his Ph.D. in computer science. His research interests are approximation, optimization, and mathematical software. His dissertation is titled “Interpolants and Error Bounds for Modeling and Predicting Variability in Computer Systems.”

Moeti Masiane, advised by Chris North, will complete his Ph.D. in computer science. He has received a graduate certificate in urban computing, a National Science Foundation-sponsored program administered through DAC. Masiane’s research interests include information visualization, data modeling, insight, sampling, and perception modeling. The title of his dissertation is “Insight Driven Sampling for Interactive Data Intensive Computing.”

Summer master’s graduate

Milad Afzalan, advised by Hoda Eldardiry, will complete his master’s degree in computer science. His research interests include machine learning, pattern recognition, smart grid, and energy efficiency. The title of his thesis is “Household electricity load shape segmentation from smart meter data based on temporal patterns and power magnitude.” Afzalan, who will also be receiving a Ph.D. from Virginia Tech in civil engineering, will join ENGIE as a data scientist.

DAC Ph.D. students Ping Wang (left) and Tian Shi are in Richland, Washington, this summer, where they are interns at the Pacific Northwest National Laboratory.

A number of graduate students at the Discovery Analytics Center have opted for internships and jobs at companies and national laboratories across the country this summer as a way of both benefiting their own research and gaining real world experience.

Following is a list of where they are for the next few months:

Aman Ahuja, a Ph.D. student in computer science, is an applied scientist intern at Amazon in Palo Alto, California. He is on the Amazon Search Team, researching product search techniques. His advisor is Chandan Reddy.

Tyler Chang, a Ph.D. student in computer science, has begun a six-month appointment at Argonne National Laboratory in Chicago, Illinois. He is one of 70 graduate students who received an appointment from the U.S. Department of Energy (DOE) Office of Science Graduate Student Research (SCGSR) to work on his thesis. The goal is to produce a portable multi-objective optimization software which Argonne could utilize in the future. Chang’s advisor is Layne Watson.

Jinwoo Choi, a Ph.D. student in electrical and computer engineering, is a research intern at NEC Labs America, San Jose, California, working on domain adaptation for video. Choi’s advisor is  Jia-Bin Huang.

Chen Gao, a Ph.D. student in electrical and computer engineering, is a research intern on a video completion project at Facebook in Seattle, Washington. He is working on an algorithm that synthesizes missing regions of videos. His advisor is Jia-Bin Huang.

Liuqing Li, a Ph.D. student in computer science, is on the Content Science team at Yahoo! Research in Sunnyvale, California, working on document recommendation through reinforcement learning. His advisor is Edward Fox.

Sneha Mehta, a Ph.D. student in computer science, is a data science intern at the Netflix headquarters in Los Gatos, California. She is researching novel methods to improve machine translation for subtitles. Her advisor is Naren Ramakrishnan.

Shruti Phadke, a Ph.D. student in computer science, is an intern at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. She is working on developing scalable machine learning and Natural Language Processing (NLP) algorithms to detect public sentiment in news and social media. Her advisor is Tanushree Mitra.

Esther Robb, a master’s degree student in electrical and computer engineering, is a research intern at Google in Mountainview, California, where she is working on facial recognition. Her advisor is Jia-Bin Huang.

Alexander Rodriguez, a Ph.D. student in computer science, is a research intern at WalmartLabs in Sunnyvale, California. His advisor is B. Aditya Prakash.

Dhruv Sharma, a master’s student in computer science, is working at Kitware, Inc., in Carborro, North Carolina. As a research and development intern, Sharma’s work includes some medical image processing/machine learning tasks; mining EHR data for prediction of risk, procedure outcome, or other events; and analyzing training needs of healthcare providers. He is advised by Chandan Reddy.

Tian Shi, a Ph.D. student in computer science, is an intern at Pacific Northwest National Laboratory in Richland, Washington, where he is working on machine comprehension and question-answering on clinical notes in the healthcare domain. His advisor is Chandan Reddy.

Shih-Yang Su, a Ph.D. student in electrical and computer engineering, is a research intern at Borealis AI in Vancouver, Canada, working on graph convolution for structural prediction. His advisor is Jia-Bin Huang.

Deepika Rama Subramanian, a master’s student in computer science, is a mobility intern at Lam Research, Fremont, California, working on designing and developing an end-to-end mobile application for field engineers at Lam Research. Her advisor is Tanushree Mitra.

Anika Tabassum, a Ph.D. student in computer science, is a research intern at the Oak Ridge National Laboratory in Oak Ridge, Tennessee, where she will be applying data mining and visualization skills in two U.S. Department of Energy (DOE) projects: “Reynolds Landing Research” and “North American Energy Resilience Model.” Her advisor is B. Aditya Prakash.

Sai Sindhura Tipirneni, a master’s student in computer science, is working in the Quantum Computing Lab at Oak Ridge National Laboratory in Oak Ridge, Tennessee. Her advisor is Chandan Reddy.

Ping Wang, a Ph.D. student in computer science, is an intern at Pacific Northwest National Laboratory in Richland, Washington, where she is working on question answering on electronic medical records using Natural Language Processing (NLP) techniques. Wang’s advisor is Chandan Reddy.

Sirui Yao, a Ph.D. student in computer science, is a research intern at Google AI in New York City, where she is studying noise and bias in dynamic recommender systems. Her advisor is Bert Huang.

Ming Zhu, a Ph.D. student in computer science, is at Amazon in Seattle, Washington. She is an applied scientist intern for Amazon Comprehend Medical, working on Natural Language Processing on medical corpora using deep learning. Zhu’s advisor is Chandan Reddy.

Yuliang Zou, a Ph.D. student in electrical and computer engineering, is a research intern at NEC Labs America in San Jose, California, where he is working on unsupervised scene structure learning. His advisor is Jia-Bin Huang.

Tyler Chang, DAC Ph.D. student in computer science

The spring semester has brought some good news for Tyler Chang, a Ph.D. student at the Discovery Analytics Center.  In June, he will begin a six-month appointment at Argonne National Lab in Washington, D.C., where he will continue to work on his dissertation while applying his work to a new set of problems relevant to the U.S. Department of Energy.

Chang, a computer science major specializing in numerical analysis, is focusing his research on interpolation and nonconvex optimization.  His advisor is Layne Watson.

The interpolation problem is to predict values between data points. “Given the total revenue earned by some small businesses and numerical descriptions of their marketing strategies, one might interpolate to predict revenue that will be earned by a new business with its own marketing strategy,” said Chang.

“The optimization problem is to find a best configuration by choosing where to sample new data points. For example,” he said, “when designing an aircraft, each design produces some amount of lift. So, an aircraft engineer might use optimization to search for the particular design that produces the maximum lift.”

His research is partially funded by the VarSys project, an interdisciplinary effort to understand and model performance variance in computer systems. The motivation for this project is that small fluctuations in the throughput, energy consumption, etc., of large machines can have significant consequences for computer system performance, behavior, and even security.

Chang said that while this may seem far removed from his research, the VarSys project can boil down to gathering performance data and then predicting performance statistics for new system configurations (the interpolation problem) and even searching for system configurations that minimize or maximize performance statistics (the optimization problem).

His bachelor’s degree from Virginia Wesleyan College is in mathematics and computer science. While an undergraduate, Chang  held a number of research internships spanning computer vision, circuit/hardware design, information visualization, autonomous driving, and parallel computing.

“As a double major, I was always looking for opportunities to apply both of my skills,” said Chang. “I discovered numerical analysis while working at Old Dominion University on a NASA grant involving computational fluid dynamics, work I initially found to be extremely challenging. But it offered the perfect marriage of passion for mathematics and computer science. My current research in interpolation and optimization allows me to channel my interest in those two fields into helping to solve a wide variety of engineering design and data science problems.”

Chang is first author on three conference papers: “Computing the Umbrella Neighbourhood of a Vertex in the Delaunay Triangulation and a Single Voronoi Cell in Arbitrary Dimension,” IEEE Southeast Con 2018; “A Polynomial Time Algorithm for Multivariate Interpolation in Arbitrary Dimension via the Delaunay Triangulation,” in Proceedings of the ACMSE 2018 Conference; and “Predicting System Performance by Interpolation Using a High-dimensional Delaunay Triangulation,” in Proceedings of the High Performance Computing Symposium (HPC ’18), Society for Computer Simulation International. Chang has also co-authored four additional conference papers.

“I love the interdisciplinary aspects of my research at DAC,” said Chang. “Through collaboration, I learn about, and even contribute to, cutting-edge research in statistics, computer systems, computer security, engineering, and other fascinating fields, all while continuing to hone my skills in numerical analysis.”

When Chang has free time he enjoys weight lifting and playing 80s and 90s rock tunes on his keyboard. While he played varsity tennis as an undergraduate, his interest in tennis is now as a fan of his sister Sophie, who is currently a top 500 professional tennis player.

Projected to graduate in 2020, Chang said he would be happy with a career in either industry or academia. “But,” he said, “having great experiences working for government labs, I would consider a position with a national lab to be my top career goal.”