The School of Science announced two new professors on its faculty in December. Heng Ji, an expert in natural language processing, has been appointed the Edward P. Hamilton Development Chair and Tenured Associate Professor in Computer Science and Karyn Rogers, a geochemist and geomicrobiologist whose research takes her to the most extreme environments capable of sustaining life on Earth, has been appointed assistant professor in the Department of Earth and Environmental Sciences.

Ji was most recently a faculty member in computer science at the City University of New York, while Rogers joins Rensselaer from the Carnegie Institution for Science in Washington, D.C.

“Heng brings an extraordinary track record of success in a very strategic research area to Rensselaer,” said Laurie Leshin, dean of the School of Science. “She’s a well-published expert in natural language processing and her intellectual leadership and energy will be critical in both the Rensselaer Institute for Data Exploration and Applications, and our work with the Watson at Rensselaer cognitive computing system. We are thrilled to welcome her to Rensselaer.”

“Karyn’s research is establishing the environmental boundaries of life leading to a greater understanding of how life may have arisen on Earth, and where it may exist elsewhere in the universe,” said Leshin. “Her work is fascinating, cutting edge, and interdisciplinary, and we are very pleased to welcome her to Rensselaer.”

Heng Ji

Ji has recently been honored with several awards, including the best paper awards at the Institute of Electrical and Electronics Engineers (IEEE) 2013 International Conference on Data Mining, and the Society of Industrial and Applied Mathematics 2013 International Conference on Data Mining. IEEE Intelligent Systems also honored Ji as one of 10 young stars in the field of artificial intelligence, naming her one of “AI’s 10 to Watch” for 2013.

The Edward P. Hamilton Development Chair is supported by an endowment established in 1976 by Edward P. Hamilton, Class of 1907. The endowment is intended to “encourage excellence in education in all fields and at all levels at Rensselaer by recognizing and rewarding an outstanding faculty member and providing resources to pursue the development of new programs.”

Ji’s current research focuses on natural language processing, with emphasis on the design of efficient algorithms that can extract knowledge and information on a massive scale from Web-based sources such as social media posts, Wikipedia articles, and news reports.

“Computer searches currently have certain limitations. If you want to use Google, for example, you have to come up with intelligent keywords, you can only search in your own language, and your search may return thousands of documents,” said Ji. “A computer that could understand natural language could overcome those limitations, and our goal is to build that computer.”

In order to understand a natural language question and provide relevant answers, Ji and her team combine the power of a sophisticated linguistic analysis function with the automation of machine learning. The system then seeks connections between the question and the Web-based information sources.

“We’re interested in how we can discover information from heterogeneous sources,” said Ji. “We want information to come from multiple languages, multiple genres, multiple data modalities, and multiple documents. When we say ‘big data,’ we are thinking more of the diversity than size of the information.”

Karyn Rogers

Karyn Rogers

Rogers researches the relationship between the geochemistry of an environment, particularly extreme environments like volcanic fumaroles and deep sea hydrothermal vents, and the microorganisms found in those environments. Her work—which supports the School of Science interdisciplinary theme in origins and fundamentals of life and matter—seeks to determine the environmental conditions that limit life on Earth, which may aid the search for life elsewhere in the universe.

“Where do we cross the line from habitable to uninhabited? And what makes an uninhabited environment unable to support life? Those are the sorts of questions I try to understand,” said Rogers.

In drawing the line between habitable and uninhabitable, Rogers focuses on bioenergetics—the energy available to an organism, through metabolic chemical reactions, from the chemicals within a given environment.

“It seems relatively straightforward: If there is a lot of energy available in an environment, there should be a lot of the microbes present that use that energy source,” said Rogers. “But life is more complicated than that, and there are other factors. Some of the factors are between organisms, like competition and syntrophy, and others concern single species, like metabolic plasticity—the ability of some organisms to use several different metabolisms. So it’s not always easy to tease apart which organisms are doing which metabolism.”

“If you look at what we know so far about the origin of life on Earth, there’s a lot of evidence in biology and geochemistry that Earth’s first life probably emerged in a high-temperature environment,” said Rogers. “And so we use these high-temperature environments as analogs for the origin of life on Earth, and the potential for life on another planet.”

Rogers combines fieldwork and lab experiments to untangle the relationships between the environment, the organisms, and their metabolism.

“In the field, we’re trying to measure the chemistry, the microbial diversity, and the activity—who’s there, who’s active, and what are they doing—and see if those parameters correlate as we go from one site to another,” said Rogers. “A big part of my research is fieldwork, which is always exciting. I’ve worked in deep sea hydrothermal systems, shallow marine hydrothermal systems, and terrestrial volcanic fumarole systems. Who wouldn’t want to go to work at the bottom of the ocean or on top of a volcano?”