Monthly Archives: November 2016

Deep learning system

Living in a dynamic physical world, it’s easy to forget how effortlessly we understand our surroundings. With minimal thought, we can figure out how scenes change and objects interact.

But what’s second nature for us is still a huge problem for machines. With the limitless number of ways that objects can move, teaching computers to predict future actions can be difficult.

Recently, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have moved a step closer, developing a deep-learning algorithm that, given a still image from a scene, can create a brief video that simulates the future of that scene.

Trained on 2 million unlabeled videos that include a year’s worth of footage, the algorithm generated videos that human subjects deemed to be realistic 20 percent more often than a baseline model.

The team says that future versions could be used for everything from improved security tactics and safer self-driving cars. According to CSAIL PhD student and first author Carl Vondrick, the algorithm can also help machines recognize people’s activities without expensive human annotations.

“These videos show us what computers think can happen in a scene,” says Vondrick. “If you can predict the future, you must have understood something about the present.”

Vondrick wrote the paper with MIT professor Antonio Torralba and Hamed Pirsiavash, a former CSAIL postdoc who is now a professor at the University of Maryland Baltimore County (UMBC). The work will be presented at next week’s Neural Information Processing Systems (NIPS) conference in Barcelona.

How it works

Multiple researchers have tackled similar topics in computer vision, including MIT Professor Bill Freeman, whose new work on “visual dynamics” also creates future frames in a scene. But where his model focuses on extrapolating videos into the future, Torralba’s model can also generate completely new videos that haven’t been seen before.

Supercomputing system

The new TX-Green computing system at the MIT Lincoln Laboratory Supercomputing Center (LLSC) has been named the most powerful supercomputer in New England, 43rd most powerful in the U.S., and 106th most powerful in the world. A team of experts at TOP500 ranks the world’s 500 most powerful supercomputers biannually. The systems are ranked based on a LINPACK Benchmark, which is a measure of a system’s floating-point computing power, i.e., how fast a computer solves a dense system of linear equations.

Established in early 2016, the LLSC was developed to enhance computing power and accessibility for more than 1,000 researchers across the laboratory. The LLSC uses interactive supercomputing to augment the processing power of desktop systems to process large sets of sensor data, create high-fidelity simulations, and develop new algorithms. Located in Holyoke, Massachusetts, the new system is the only zero-carbon supercomputer on the TOP500 list; it uses energy from a mixture of hydroelectric, wind, solar, and nuclear sources.

In November, Dell EMC installed a new petaflop-scale system, which consists of 41,472 Intel processor cores and can compute 1015 operations per second. Compared to LLSC’s previous technology, the new system provides 6 times more processing power and 20 times more bandwidth. This technology enables research in several laboratory research areas, such as space observation, robotic vehicles, communications, cybersecurity, machine learning, sensor processing, electronic devices, bioinformatics, and air traffic control.

The LLSC mission is to address supercomputing needs, develop new supercomputing capabilities and technologies, and collaborate with MIT campus supercomputing initiatives. “The LLSC vision is to enable the brilliant scientists and engineers at Lincoln Laboratory to analyze and process enormous amounts of information with complex algorithms,” says Jeremy Kepner, Lincoln Laboratory Fellow and head of the LLSC. “Our new system is one of the largest on the East Coast and is specifically focused on enabling new research in machine learning, advanced physical devices, and autonomous systems.”

Because the new processors are similar to the prototypes developed at the laboratory more than two decades ago, the new petaflop system is compatible with all existing LLSC software. “We have had many years to prepare our computing system for this kind of processor,” Kepner says. “This new system is essentially a plug-and-play solution.”

Outsized influence on organizational

Jay W. Forrester SM ’45, professor emeritus in the MIT Sloan School of Management, founder of the field of system dynamics, and a pioneer of digital computing, died Nov. 16. He was 98.

Forrester’s time at MIT was rife with invention. He was a key figure in the development of digital computing, the national air defense system, and MIT’s Lincoln Laboratory. He developed servomechanisms (feedback-based controls for mechanical devices), radar controls, and flight-training computers for the U.S. Navy. He led Project Whirlwind, an early MIT digital computing project. It was his work on Whirlwind that led him to invent magnetic core memory, an early form of RAM for which he holds the patent, in 1949.

MIT Sloan Professor John Sterman, a student, friend, and colleague of Forrester’s since the 1970s, points to a 2003 photo of Forrester on a Segway as an illustration of his work’s lasting impact.

“He really is standing on top of the fruits of his many careers,” Sterman said. “He’s standing on a device that integrates servomechanisms, digital controllers, and a sophisticated feedback control system.”

“From the air traffic control system to 3-D printers, from the software companies use to manage their supply chains to the simulations nations use to understand climate change, the world in which we live today was made possible by Jay’s work,” he said.

Systems dynamics: A new view of management

It was after turning his attention to management in the mid-1950s that Forrester developed system dynamics — a model-based approach to analyzing complex organizations and systems — while studying a General Electric appliance factory. An MIT Technology Review article explores how he sought to combat the factory’s boom-and-bust cycle by examining its “weekly orders, inventory, production rate, and employees.” He then developed a computer simulation of the GE supply chain to show how management practices, not market forces, were causing the cycle.

Forrester’s “Industrial Dynamics” was published in 1961. The field expanded to chart the complexities of economies, supply chains, and organizations. Later, he cast the principles of system dynamics on global issues in “Urban Dynamics,” published in 1969, and “World Dynamics,” published in 1971. The latter was an integrated simulation model of population, resources, and economic growth. Forrester became a critic of growth, a position that earned him few friends.

Plain text into data for statistical analysis

The vast wealth of information unlocked by the Internet, most is plain text. The data necessary to answer myriad questions — about, say, the correlations between the industrial use of certain chemicals and incidents of disease, or between patterns of news coverage and voter-poll results — may all be online. But extracting it from plain text and organizing it for quantitative analysis may be prohibitively time consuming.

Information extraction — or automatically classifying data items stored as plain text — is thus a major topic of artificial-intelligence research. Last week, at the Association for Computational Linguistics’ Conference on Empirical Methods on Natural Language Processing, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory won a best-paper award for a new approach to information extraction that turns conventional machine learning on its head.

Most machine-learning systems work by combing through training examples and looking for patterns that correspond to classifications provided by human annotators. For instance, humans might label parts of speech in a set of texts, and the machine-learning system will try to identify patterns that resolve ambiguities — for instance, when “her” is a direct object and when it’s an adjective.

Typically, computer scientists will try to feed their machine-learning systems as much training data as possible. That generally increases the chances that a system will be able to handle difficult problems.

In their new paper, by contrast, the MIT researchers train their system on scanty data — because in the scenario they’re investigating, that’s usually all that’s available. But then they find the limited information an easy problem to solve.

“In information extraction, traditionally, in natural-language processing, you are given an article and you need to do whatever it takes to extract correctly from this article,” says Regina Barzilay, the Delta Electronics Professor of Electrical Engineering and Computer Science and senior author on the new paper. “That’s very different from what you or I would do. When you’re reading an article that you can’t understand, you’re going to go on the web and find one that you can understand.”

Venture capitalists gather to discuss

Surviving breast cancer changed the course of Regina Barzilay’s research. The experience showed her, in stark relief, that oncologists and their patients lack tools for data-driven decision making. That includes what treatments to recommend, but also whether a patient’s sample even warrants a cancer diagnosis, she explained at the Nov. 10 Machine Intelligence Summit, organized by MIT and venture capital firm Pillar.

“We do more machine learning when we decide on Amazon which lipstick you would buy,” said Barzilay, the Delta Electronics Professor of Electrical Engineering and Computer Science at MIT. “But not if you were deciding whether you should get treated for cancer.”

Barzilay now studies how smarter computing can help patients. She wields the powerful predictive approach called machine learning, a technique that allows computers, given enough data and training, to pick out patterns on their own — sometimes even beyond what humans are capable of pinpointing.

Machine learning has long been vaunted in consumer contexts — Apple’s Siri can talk with us because machine learning enables her to understand natural human speech — yet the summit gave a glimpse of the approach’s much broader potential. Its reach could offer not only better Siris (e.g., Amazon’s “Alexa”), but improved health care and government policies.

Machine intelligence is “absolutely going to revolutionize our lives,” said Pillar co-founder Jamie Goldstein ’89. Goldstein and Anantha Chandrakasan, head of the MIT Department of Electrical Engineering and Computer Science (EECS) and the Vannevar Bush Professor of Electrical Engineering and Computer Science, organized the conference to bring together industry leaders, venture capitalists, students, and faculty from the Computer Science and Artificial Intelligence (CSAIL), Institute for Data, Systems, and Society (IDSS), and the Laboratory for Information and Decision Systems (LIDS) to discuss real-world problems and machine learning solutions.

Barzilay is already thinking along those lines. Her group’s work aims to help doctors and patients make more informed medical decisions with machine learning. She has a vision for the future patient in the oncologist’s office: “If you’re taking this treatment, [you’ll see] how your chances are going to be changed.”

Machine senses

Machine learning has already proven powerful. But Antonio Torralba, professor of electrical engineering and computer science, believes that machines can learn faster, and thereby do more. His team’s approach mimics the way humans learn in infancy. “We just start playing with things and seeing how they feel,” Torralba said. To illustrate, he showed the room a video of a baby turning over squeaky bubble wrap in her hands. Importantly, we notice the noises things make when we move them around, he said.

Powerful than previously realized

Quantum computers promise huge speedups on some computational problems because they harness a strange physical property called entanglement, in which the physical state of one tiny particle depends on measurements made of another. In quantum computers, entanglement is a computational resource, roughly like a chip’s clock cycles — kilohertz, megahertz, gigahertz — and memory in a conventional computer.

In a recent paper in the journal Proceedings of the National Academy of Sciences, researchers at MIT and IBM’s Thomas J. Watson Research Center show that simple systems of quantum particles exhibit exponentially more entanglement than was previously believed. That means that quantum computers — or other quantum information devices — powerful enough to be of practical use could be closer than we thought.

Where ordinary computers deal in bits of information, quantum computers deal in quantum bits, or qubits. Previously, researchers believed that in a certain class of simple quantum systems, the degree of entanglement was, at best, proportional to the logarithm of the number of qubits.

“For models that satisfy certain physical-reasonability criteria — i.e., they’re not too contrived; they’re something that you could in principle realize in the lab — people thought that a factor of the log of the system size was the best you can do,” says Ramis Movassagh, a researcher at Watson and one of the paper’s two co-authors. “What we proved is that the entanglement scales as the square root of the system size. Which is really exponentially more.”

That means that a 10,000-qubit quantum computer could exhibit about 10 times as much entanglement as previously thought. And that difference increases exponentially as more qubits are added.