Faculty

Debiasing artificial intelligence (AI)

In the medical field, AI encompasses a suite of technologies that can help diagnose patients’ ailments, improve health care delivery and enhance basic research. The technologies involve algorithms, or instructions, run by software. These algorithms can act like an extra set of eyes perusing lab tests and radiological images; for instance, by parsing CT scans for particular shapes and color densities that could indicate disease or injury.

Problems of bias can emerge, however, at various stages of these devices’ development and deployment, James explained. One major factor is that the data for forming models used by algorithms as baselines can come from nonrepresentative patient datasets.

By failing to properly take race, sex and socioeconomic status into account, these models can be poor predictors for certain groups. To make matters worse, clinicians might lack any awareness of AI medical devices potentially producing skewed results. 

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Congratulations to Professor Boris Murmann for receiving the 2021 Semiconductor Industry Association (SIA)-SRC University Researcher Award. Award winners are selected by SRC members who truly recognize great contributions to the semiconductor industry.

Source: src.org/award/university-researcher/

The SIA University Research Award was established in 1995 by the Semiconductor Industry Association (SIA) to recognize lifetime research contributions to the U.S. semiconductor industry by university faculty.

Please join us in recognizing Boris for his significant contributions in the semiconductor industry.

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Congratulations to Professor Subhasish Mitra for receiving the 2021 Semiconductor Industry Association (SIA)-SRC University Researcher Award. Award winners are selected by SRC members who truly recognize great contributions to the semiconductor industry.

Please join us in recognizing Subhasish for his significant contributions in the semiconductor industry.

The SIA University Research Award was established in 1995 by the Semiconductor Industry Association (SIA) to recognize lifetime research contributions to the U.S. semiconductor industry by university faculty.

Source: SRC.org/award/university-researcher

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• Subhasish Mitra, H.S. Philip Wong, and Mary Wootters' system can run AI tasks faster and with less energy

A team of Stanford researchers including EE Professor Eric Pop report the design and fabrication of single-wall carbon nanotube thermoelectric devices on flexible polyimide substrates as a basis for wearable energy converters.

source: ScienceDaily.com [...]
Inspiration came from a desire to ultimately fabricate energy converting devices from the same materials as the active devices themselves, so they can blend in as an integral part of the total system. Today, many biomedical nanodevices' power supplies come from several types of batteries that must be separated from the active portion of the systems, which is not ideal.

In Applied Physics Letters, the researchers report the design and fabrication of single-wall carbon nanotube thermoelectric devices on flexible polyimide substrates as a basis for wearable energy converters.

"Carbon nanotubes are one-dimensional materials, known for good thermoelectric properties, which mean developing a voltage across them in a temperature gradient," said Professor Eric Pop. "The challenge is that carbon nanotubes also have high thermal conductivity, meaning it's difficult to maintain a thermal gradient across them, and they have been hard to assemble them into thermoelectric generators at low cost."

The group uses printed carbon nanotube networks to tackle both challenges.

Professor Pop continued, "For example, carbon nanotube spaghetti networks have much lower thermal conductivity than carbon nanotubes taken alone, due to the presence of junctions in the networks, which block heat flow. Also, direct printing such carbon nanotube networks can significantly reduce their cost when they are scaled up."

Thermoelectric devices generate electric power locally "by reusing waste heat from personal devices, appliances, vehicles, commercial and industrial processes, computer servers, time-varying solar illumination, and even the human body," said Hye Ryoung Lee, lead author and a research scientist.

"To eliminate hindrances to large-scale application of thermoelectric materials – toxicity, materials scarcity, mechanical brittleness – carbon nanotubes offer an excellent alternative to other commonly used materials," Lee said.

The group's approach demonstrates a path to using carbon nanotubes with printable electrodes on flexible polymer substrates in a process anticipated to be economical for large-volume manufacturing. It is also "greener" than other processes, because water is used as the solvent and additional dopants are avoided.

Excerpted from "Nontoxic, flexible energy converters could power wearable devices" April 27, 2021

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• "Nontoxic, Flexible Energy Converters Could Power Wearable Devices", Applied Physics Letters. April 27, 2021
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Professor Shanhui Fan presented his latest advances in radiative cooling at annual energy sector conference. Shanhui's radiative cooling harvests electricity from the coldness of the universe, which in turn, can be harvested on Earth for several renewable energy applications. For millennia, humans in regions where the ambient temperature never falls below freezing have used the concept to make ice by burying water at night.

Radiative cooling could have a significant impact on lowering electricity use and boosting output of renewables, but it will require advances in blackbody emitters, materials that absorb heat and radiate the heat at frequencies that send it into space.

"This requires a good blackbody emitter," said Shanhui, "but we can cool objects to a temperature 13 degrees Celsius (55 degrees Fahrenheit) below the ambient temperature with no electricity; it's purely passive cooling."

Radiative cooling systems could, for example, reduce the electricity required for air conditioning by 10 percent to 15 percent, he said. Such systems at night could also generate enough electricity for LED lighting in homes, which would be a significant development for the billion humans without electricity.

Other Stanford faculty research presented includes,

• Professor Yi Cui, discussed new horizons for energy and climate research as part of a panel. To Cui, the big issue is energy storage to enable greater use of intermittent solar and wind power.
• Professor Reihold Dauskardt's Spray-on Solar cells
• Professor Arun Majumdar discussed gigaton-scale solutions for getting to zero greenhouse gas emissions globally from human activity.

Excerpted from Precourt Institute "Stanford at CERAWeek: energy storage, net-zero GHG, radiative cooling and perovskite solar cells"

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Professor Kunle Olukotun has built a career out of building computer chips for the world.

These days his attention is focused on new-age chips that will broaden the reach of artificial intelligence to new uses and new audiences — making AI more democratic.

The future will be dominated by AI, he says, and one key to that change rests in the hardware that makes it all possible — faster, smaller, more powerful computer chips. He imagines a world filled with highly efficient, specialized chips built for specific purposes, versus the relatively inefficient but broadly applicable chips of today.

Making that vision a reality will require hardware that focuses less on computation and more on streamlining the movement of data back and forth, a function that now claims 90% of computing power, as Kunle tells host Russ Altman on this episode of Stanford Engineering's The Future of Everything podcast. 

Source: The Future of Everything Series, "Kunle Olukotun: How to make AI more democratic"

Later this year, in a lab in the Durand Building, a team of researchers will demonstrate how a tight formation of computer-controlled drones can be managed with precision even when the 5G network controlling it is under continual cyberattack. The demo's ultimate success or failure will depend on the ability of an experimental network control technology to detect the hacks and defeat them within a second to safeguard the navigation systems.

On hand to observe this demonstration will be officials from DARPA, the Defense Advanced Research Projects Agency, the government agency that's underwriting Project Pronto. The $30 million effort, led by Professor Nick McKeown, is largely funded and technically supported through the nonprofit Open Networking Foundation (ONF), with help from Princeton and Cornell universities. Their goal: to make sure that the wireless world – namely, 5G networks that will support the autonomous planes, trains and automobiles of the future – remains secure and reliable as the wired networks we rely on today.

This is no small task and the consequences could not be greater. The transition to 5G will affect every device connected to the internet and, by extension, the lives of every person who relies on such networks for safe transportation. But, as recent intrusions into wired networks have shown, serious vulnerabilities exist.

The pending Pronto demo is designed to solve that problem by way of a fix that McKeown and colleagues have devised that wraps a virtually instantaneous shield around wirelessly accessible computers using a technology known as software-defined networking (SDN).

Excerpted from "A new Stanford initiative aims to ensure 5G networks are reliable and secure", Stanford News, March 24, 2021.

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Professor David Miller joins Professor Russ Altman on The Future of Everything podcast. David's research interests include the use of optics in switching, interconnection, communications, computing, and sensing systems, physics and applications of quantum well optics and optoelectronics, and fundamental features and limits for optics and nanophotonics in communications and information processing. 

In this podcast he explains the remarkable potential of using light instead of electricity in computation.

"A silicon chip these days looks like six Manhattan grids stacked atop one another," Miller says of the challenge facing today's technology. Photonics holds the promise of more powerful computing by beaming tiny packets of photons through light-bearing conduits that carry 100,000 times more data than today's comparable wires, and it can do it using far less energy, too.

Before that day can arrive, however, Miller says photonic components need to become much smaller and less expensive to compete with the sheer scale advantages silicon enjoys, and that will require investment. But, for once, a way forward is there for the asking, as Miller tells bioengineer Russ Altman, host of Stanford Engineering's The Future of Everything podcast. Listen and subscribe here.

Professor Kunle Olukotun has been elected to the National Academy of Engineering, "for contributions to on-chip multiprocessor architectures and advancement to commercial realization." Kunle will be formally inducted during the NAE's annual meeting on October 3.

Election to the National Academy of Engineering is among the highest professional distinctions accorded to an engineer. Academy membership honors those who have made outstanding contributions to "engineering research, practice, or education, including, where appropriate, significant contributions to the engineering literature" and to "the pioneering of new and developing fields of technology, making major advancements in traditional fields of engineering, or developing/implementing innovative approaches to engineering education."

Hearty congratulations to Kunle on this well-deserved recognition!

Read National Academy of Engineering Press Release