News featuring Tianyi Li

Congratulations to DAC’s 2020 Spring and Summer Graduates!

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 Student Spotlight: Tianyi Li

Tianyi Li, DAC Ph.D. student in computer science

How do we form our opinions? How do we develop the mental models that make us different and unique?

Finding answers to these questions is what drives Tianyi Li’s research at the Discovery Analytics Center. As a Ph.D. student in computer science, her research interests include human-computer interaction (HCI), collective (crowdsourced) intelligence, visual analytics, and explainable artificial intelligence (AI).

“I have always been interested in human cognition and intelligence, especially the sensemaking process,” said Li, who is advised by Chris North at DAC and co-advised by Kurt Luther. “Studying computer science during my undergrad years at Hong Kong University made me think deeper about the relationship between human and computing intelligence. I am excited by how much computer science has been advancing our understanding of the black box of human intelligence by developing smarter and human-friendly technologies.”

Li’s thesis work is focused on how to modularize the complex sensemaking process so that many distributed agents can contribute to suitable components asynchronously and meaningfully. Specifically, Li explores, incites, acquires, and structures the wisdom of crowds to help make sense of the rapidly growing and dynamically changing information about the world. To achieve this goal, her work combines sensemaking theories, crowdsourcing techniques, and visual analytics tools to develop theories and applications for intelligence analysis.

“I like the great support I have in DAC,” said Li. “Many professors and students sit in the same area. Everybody is friendly, smart, and helpful. I am also benefiting a lot from my talented lab mates from diverse backgrounds and brilliant advisor Dr. North. The great lab atmosphere is really helping me grow into a more confident and mature researcher.”

Next month, Li will be at the ACM IUI 2019 conference in Los Angeles to present “What Data Should I Protect? Recommender and Planning Support for Data Security Analysts.” Last November, she presented the paper, CrowdIA: Solving Mysteries with Crowdsourced Sensemaking,” at the 21st ACM Conference on Computer-Supported Cooperative Work and Social Computing (CSCW).

During an internship at Cloudera in Palo Alto, California, last summer, Li conducted interviews with data science practitioners in industry to collect user requirements and identify opportunities for leveraging interactive visual support and developed a prototype system called HyperTuner that supports hyper parameter search and analysis via interactive visual analytics.

In the summer of 2017, Li interned at Informatica in Redwood City, California. Her work there involved identifying what data is worth protecting and building an impactful plan to protect it. “I implemented a system prototype through four iterative design and evaluation cycles by applying user-centered design to this new domain of data security applications,” she said.

Li’s projected graduation date is Spring 2020. She said that based on her experience so far, she likes working both in academia and in industry. “Right now, I am just trying to work hard to keep both doors open until I finally decide which one to commit to,” she said.


DAC students use summer months to broaden knowledge at tech-related jobs across the U.S.

Michelle Dowling, DAC Ph.D. student in computer science, teaching at her alma mater, Grand Valley State University.

Students at the Discovery Analytics Center have headed off to summer jobs and internships from coast to coast. Following is a good example of the kind of real world experience they are getting.

Payel Bandyopadhyay, a Ph.D. student in computer science, is working on data visualization at UPS Advanced Technology Group, Atlanta, Georgia, where she is helping redesign the UPS parcel tracker website. Her advisor is Chris North.

Jinwoo Choi, a Ph.D. student in electrical and computer engineering, is a computer vision researcher at NEC Labs America, Cupertino, California, working in the area of video understanding/action recognition. Choi’s advisor is Jia-Bin Huang.

Michelle Dowling, a Ph.D. student in computer science, is an instructor at her alma mater, Grand Valley State University in Allendale, Michigan.  She is co-teaching an introductory computer science course with Professor Roger Ferguson. Dowling’s advisor is Chris North.

Shuangfei Fan, a Ph.D. student in computer science, is a software engineer at Instagram in New York City. Her advisor is Bert Huang.

Abhinav Kumar, a master’s student in computer science, is an intern at PayPal in San Jose, California, where he is working on credit risk centric problems. His advisor is Edward Fox.

Tianyi Li, a Ph.D. student in computer science, is a software engineer at Cloudera, in Palo Alto, California, working on visual analytics for interpreting and better training machine learning models. Her advisor is Chris North.

Yufeng Ma, a Ph.D. student in computer science, is a research scientist at Yahoo! Research, in Sunnyvale, California, where he will apply deep learning techniques to data with both images and text. Ma’s advisor is Weiguo (Patrick) Fan and his co-advisor is Edward Fox.

Elaheh Raisi, a Ph.D. student in computer science is a data scientist on the Global Risk and Data Sciences team at PayPal in San Jose, California. This team is responsible for developing and enhancing machine learning and data mining capabilities, which are key to PayPal’s top-of-the-line data-driven decisions. Raisi’s advisor is Bert Huang.

John Wenskovitch, a Ph.D. student in computer science, is visualizing sequential content in multimodal documents/reports in team collaboration settings at FXPAL in Palo Alto, California. His advisor is Chris North.

Sirui Yao, a Ph.D. student in computer science, is a research scientist at Walmart in Bentonville, Arkansas.  She is working on a project that uses machine learning to build a hiring tool, an intelligent system that assists Human Resources in selecting candidate resumes. She will also study related issues such as fairness and security. Yao’s advisor is Bert Huang.

Xuchao Zhang, a Ph.D. student in computer science, will be researching argumentative zoning and note-taking behavior during document authoring at Microsoft Research AI, in Redmond, Washington.  Zhang’s advisor is Chang-Tien Lu.

Yuliang Zou, a Ph.D. student in electrical and computer engineering, will be a researcher at Adobe Research, San Jose, California. His advisor is Jia-Bin Huang.

Sneha Mehta, a Ph.D. student in computer science, is at the Netflix headquarters in Los Gatos, California, working on the open-ended problem of using Natural Language Processing (NLP) techniques to tangibly improve the quality of machine translated subtitles. Her advisor is Naren Ramakrishnan.

“Our DAC students greatly benefit from being out in the workforce during the summer months,” said Naren Ramakrishnan, the Thomas L. Phillips Professor of Engineering in the Department of Computer Science and director of the Discovery Analytics Center. “In addition to contributing their skills to problems faced by companies, what they learn from these opportunities is invaluable and an important part of their graduate education.”