Faculty

September 2016

For years, the net neutrality debate has been at an impasse: either the internet is open or preferences are allowed. But professors Nick McKeown and Sachin Katti, and EE PhD Yiannis Yiakoumis ­– say their new technology, called Network Cookies, makes it possible to have preferential delivery and an open internet. Network Cookies allow users to choose which home or mobile traffic should get favored delivery, while putting network operators and content providers on a level playing field in catering to such user-signaled preferences.

"So far, net neutrality has been promoted as the best possible defense for users," Katti said. "But treating all traffic the same isn't necessarily the best way to protect users. It often restricts their options and this is why so-called exceptions from neutrality often come up. We think the best way to ensure that ISPs and content providers don't make decisions that conflict with the interests of users is to let users decide how to configure their own traffic."

McKeown said Network Cookies implement user-directed preferences in ways that are consistent with the principles of net neutrality.

"First, they're simple to use and powerful," McKeown said. "They enable you to fast-lane or zero-rate traffic from any application or website you want, not just the few, very popular applications. This is particularly important for smaller content providers – and their users – who can't afford to establish relationships with ISPs. Second, they're practical to deploy. They don't overwhelm the user or bog down user devices and network operators and they function with a variety of protocols. Finally, they can be a very practical tool for regulators, as they can help them design simple and clear policies and then audit how well different parties adhere to them."

 


This article is adapted from Stanford Engineering News. Read full article.

September 2016

Technology developed by Stanford Bio-X scientists Krishna Shenoy (EE) and postdoctoral fellow Paul Nuyujukian, directly reads brain signals to drive a cursor moving over a keyboard. In an experiment conducted with monkeys, the animals were able to transcribe passages from the New York Times and Hamlet at a rate of up to 12 words per minute.

Earlier versions of the technology have already been tested successfully in people with paralysis, but the typing was slow and imprecise. This latest work tests improvements to the speed and accuracy of the technology that interprets brain signals and drives the cursor.

"Our results demonstrate that this interface may have great promise for use in people," said Nuyujukian, who will join Stanford faculty as an assistant professor of bioengineering in 2017. "It enables a typing rate sufficient for a meaningful conversation."

The technology developed by the Stanford team involves a multi-electrode array implanted in the brain to directly read signals from a region that ordinarily directs hand and arm movements used to move a computer mouse.

It's the algorithms for translating those signals and making letter selections that the team members have been improving. They had tested individual components of the updated technology in prior monkey studies but had never demonstrated the combined improvements in typing speed and accuracy.

"The interface we tested is exactly what a human would use," Nuyujukian said. "What we had never quantified before was the typing rate that could be achieved." Using these high-performing algorithms developed by Nuyujukian and his colleagues, the animals could type more than three times faster than with earlier approaches.

 

This article is adapted from the Stanford Report. Read full article.

 

Related News:

Krishna Shenoy's translation device; turning thought into movement, March 2017.

Krishna Shenoy receives Inaugural Professorship, February 2017.


 

September 2016

This month’s issue of IEEE Solid-State Circuits Magazine contains six feature articles on Mark Horowitz. The articles are a testament to Mark’s decades of contributions, covering his journey from childhood, his contributions to computer architecture and industry, and his guidance of Stanford PhD candidates who continue to become influential researchers.

The six articles by former students, colleagues, collaborators, and Mark himself are titled:

  • The Art of Breaking and Making
  • Mark Horowitz and his Impact on Computer Architecture
  • Rambus
  • Mark Horowitz’s Link for Chip-to-Chip Communication
  • The Legacy of Mark Horowitz in Me
  • Enabling the Hardware for Computational Photography

 

Congratulations to Mark on this unique honor. The articles are available as PDFs from the IEEE Solid-State Circuits Magazine.

This article is adapted from the IEEE Solid-State Circuits Magazine.

September 2016

As the breathalyzer does for alcohol, this experimental 'potalyzer' could provide a practical field test for determining whether a driver might be impaired from smoking marijuana.

This November, several states will vote whether to legalize marijuana use, joining more than 20 states that already allow some form of cannabis use. This has prompted a need for effective tools for police to determine on the spot whether people are driving under the influence.

Shan Wang and team have devised a potential solution, applying magnetic nanotechnology (GMR), previously used as a cancer screen, to create what could be the first practical roadside test for marijuana intoxication.

"To the best of our knowledge, this is the first demonstration that GMR biosensors are capable of detecting small molecules," Wang wrote in a paper describing the device, published in Analytical Chemistry.

Professor Shan Wang and team created a mobile device that uses magnetic biosensors to detect tiny THC molecules in saliva. Officers could collect a spit sample with a cotton swab and read the results on a smartphone or laptop in as little as three minutes.

Wang's device can detect concentrations of THC in the range of 0 to 50 nanograms per milliliter of saliva. While there's still no consensus on how much THC in a driver's system is too much, previous studies have suggested a cutoff between 2 and 25 ng/mL, well within the capability of Wang's device.

 

The co-authors of the Analytical Chemistry paper are Jung-Rok Lee (ME PhD'15), Joohong Choi (EE PhD'15), and Tyler O. Shultz (Biology BS'13).

 

This article is adapted from the Stanford Report.

September 2016

Shanhui Fan and research team are developing a material that cools by letting perspiration evaporate through the material – something ordinary fabrics already do. But the Stanford material provides a second, revolutionary cooling mechanism: allowing heat that the body emits as infrared radiation to pass through the plastic textile.

"Forty to 60 percent of our body heat is dissipated as infrared radiation when we are sitting in an office," states Shanhui Fan, who specializes in photonics. "But until now there has been little or no research on designing the thermal radiation characteristics of textiles."

To develop their cooling textile, the Stanford researchers blended nanotechnology, photonics and chemistry to give polyethylene – the clear, clingy plastic we use as kitchen wrap – a number of characteristics desirable in clothing material: It allows thermal radiation, air and water vapor to pass right through, and it is opaque to visible light.

Eventually, the research culminated in a single-sheet material that met their three basic criteria for a cooling fabric. To make this thin material more fabric-like, they created a three-ply version: two sheets of treated polyethylene separated by a cotton mesh for strength and thickness.

"Wearing anything traps some heat and makes the skin warmer," Fan said. "If dissipating thermal radiation were our only concern, then it would be best to wear nothing."

Comparing the new fabric with cotton fabric, showed cotton making the skin surface 3.6 F warmer than their cooling textile. The researchers said this difference means that a person dressed in their new material might feel less inclined to turn on a fan or air conditioner.

Fan believes that this research opens up new avenues of inquiry to cool or heat things, passively, without the use of outside energy, by tuning materials to dissipate or trap infrared radiation.

 

 

This article is adapted from the Stanford Report.
Read full article

August 2016

The Precourt Institute for Energy and the TomKat Center for Sustainable Energy at Stanford have awarded 15 seed grants to clean energy research projects.

The seed-grant program funds innovative research proposals that have the potential for high impact on energy supply and use. The 2016 awards total $2.7 million, and have been awarded to 15 projects at Stanford and SLAC. "I'm especially pleased that this year's recipients reflect the broad diversity of energy research across campus, including the schools of engineering, law, business and medicine, as well as the SLAC National Accelerator Laboratory," stated Precourt Institute for Energy co-director and professor of mechanical engineering Arun Majundar.

Three projects lead or co-lead by EE faculty received grants.

  • A modular multi-level photovoltaic converter:This project aims to minimize cost and power losses in transformers for grid-scale solar installations by developing new technology for the efficient conversion of direct current to alternating current. PI: William Dally, Electrical Engineering/Computer Science.
  • Building the power electronics cell: Researchers will design a high power-density, bidirectional AC-DC converter cell that can be combined into a charger-inverter pack that generates enough energy to power an electric vehicle. PI: Juan Rivas-Davila, Electrical Engineering.
  • Novel fabrication of light-emitting diodes (LEDs): This project seeks to reduce the cost of manufacturing high-efficiency LEDs for industry and consumers. PIs: Bruce Clemens, Materials Science and Engineering, and James Harris, Electrical Engineering.

Read the full article from the Stanford Report

This article is adapted from the Stanford Report.

August 2016

Howard Zebker has been chosen as one of 60 new fellows of the American Geophysical Union (AGU). He will be honored at the AGU's upcoming fall meeting in San Francisco.

Since 1962, the AGU has elected outstanding members as Union Fellows. This special honor recognizes scientific eminence in the Earth and space sciences. It acknowledges fellows for their remarkable contributions to their research fields, exceptional knowledge and visionary leadership. Only 0.1 percent of AGU membership receives this recognition in any given year.

Zebker, who earned a PhD from Stanford, is professor of electrical engineering and of geophysics and is an affiliate of the Stanford Woods Institute for the Environment. His research focuses on developing space-borne radar systems and applying remote sensing data to problems in geophysics. His current emphasis is on interferometric radar for natural hazards, water resources and global environmental problems. He is also active in planetary science. Read the American Geophysical Union (AGU) press release.

Howard's research consists of developing spaceborne radar systems and applying remote sensing data to problems in geophysics. His current emphasis is on interferometric radar for natural hazards, water resources, and global environmental problems. He is also active in planetary science, in particular research supporting the NASA Cassini mission to Saturn and Titan.

Professor Zebker's courses include:

 

Source: Stanford Report, August 2, 2016

July 2016

IEEE Information Theory Society announced that David Tse will be awarded the 2017 Claude E. Shannon Award. The Shannon Award honors consistent and profound contributions to the field of information theory. Announced during the 2016 IEEE International Symposium on Information Theory in Barcelona, Professor Tse was humbled and gratefully acknowledged the distinction.

David Tse is a leading figure in Information Theory & Applications. He has received numerous best paper awards from information theory, communications, signal processing and networking communities. His work is incorporated in cellular wireless standards. He also co-authored the text, "Fundamentals of Wireless Communication", which has influenced generations of wireless engineers and researchers. His research at Stanford focuses on applying information theory to computational biology and machine learning.

The Claude E. Shannon Award is the highest honor from the IEEE Information Theory Society. The award recognizes consistent and profound contributions to the field of information theory. We proudly congratulate David Tse for this very well deserved recognition.

David will be the Shannon Lecturer at the 2017 IEEE International Symposium on Information Theory in Aachen, Germany.

July 2016

Research by Subhasish Mitra and H.-S. Philip Wong explore carbon nanotubes and their potential for boosting computing performance and capability. In a video produced by the National Science Foundation's online magazine, Science Nation, Subhasish and Philip describe the state of CNT research.

A Stanford School of Engineering article provides an overview. 

May 2016

Early results show that the quality of optical materials grown from diamondoid seeds is consistently high, says Stanford's Jelena Vuckovic, a professor of electrical engineering who is leading this part of the research with Steven Chu, professor of physics and of molecular and cellular physiology.

"Developing a reliable way of growing the nanodiamonds is critical," says Vuckovic, who is also a member of Stanford Bio-X and SystemX. "And it's really great to have that source and the grower right here at Stanford. Our collaborators grow the material, we characterize it and we give them feedback right away. They can change whatever we want them to change."

 

Excerpted from Stanford News. Read full article.

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