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A photo illustration shows the icons that represent several web browsers, incluing Chrome and Firefox, in a row

Browser Fingerprinting Tech Works Across Different Browsers for the First Time

Browsing the Web just got a little less anonymous. The software that lets websites identify you by certain characteristics of your computer and software was usually thwarted if you switched browsers. But now computer scientists have developed new browser fingerprinting software that identifies users across Web browsers with a degree of accuracy that beats the most sophisticated single-browser techniques used today.

The new method, created by Yinzhi Cao, a computer science professor at Lehigh University, in Pennsylvania, accurately identifies 99.24 percent of users across browsers, compared to 90.84 percent of users identified by AmIUnique, the most advanced single-browser technique.

Browser fingerprinting is an online tracking technique commonly used to authenticate users for retail and banking sites and to identify them for targeted advertising. By combing through information available from JavaScript and the Flash plugin, it’s possible for third parties to create a “fingerprint” for any online user.

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A blue-gloved hand bending a piece of silvery-plastic film containing the artificial synapse

A Low-Power Artificial Synapse Could One Day Interface With the Brain

A team based at Stanford University and at Sandia National Laboratories, in Livermore, Calif., have created a new form of “artificial synapse” that may one day be used to create flexible circuitry that could directly interface with the brain.

The new device, a form of organic transistor that the team calls an electrochemical neuromorphic organic device (ENODe), joins the ranks of technologies such as the memristor and phase-change memory: devices that may one day be used to create chips that can perform brain-like computations using far less power than even the most state-of-the-art silicon systems consume. 

In some ways, ENODe resembles a battery more than it does a transistor. Two thin polymer films are separated by an electrolyte that allows protons to pass through but not electrons. But like transistors, the device has three terminals. Current flows between two of them through the “postsynaptic” film. The third terminal is attached to the other (“presynaptic”) film. A voltage pulse at the presynaptic terminal causes charges to flow through the electrolyte either in or out of the postsynaptic film. This results in a change in the oxidation level which determines how much the film resists the flow of current through it. The details were published this week in Nature Materials

According to co-author Alec Talin of Sandia, the new device circumvents a limitation that other (two-terminal) artificial synapses suffer from: the fairly high level of energy needed to switch from one state to another. Typically, if the energy barrier to switch is too low in those devices, thermal fluctuations are enough to overcome it, meaning the device can switch states at random. “There’s no way to get around it,” Talin says, “because if you lower that voltage, it would simply switch back.”

The ENODe doesn’t have this problem, the authors write, because the barrier that maintains the state of the device is unrelated to the one that governs switching.  As a result, the device can be designed to need little voltage to switch, and yet it will retain the resulting state for a long time. “Just like battery, once you charge it stays charged,” says Talin, who co-led the research with Alberto Salleo at Stanford.

The new device can exhibit more than 500 different states of conductivity within about a 1 V range, using a switching voltage of roughly 0.5 millivolts between adjacent states. That might sound exceedingly low for those familiar with modern silicon transistors and so are accustomed to thinking in volts. But the device still uses about 10,000 times as much energy as a biological synapse would, a Stanford press release reports. Miniaturization is expected to help with that. 

The device has several electronic properties that make it especially attractive for brain-mimicking neuromorphic computing chips, Talin says. And he notes that the same material used to make these devices has already been used to interface with live brain cells. “That opens up a possibility of interfacing live biological cells [with circuits] that can do computing via artificial synapses,” Talin says. “We think that could have huge implications in the future for creating much better brain-machine interfaces.”

To demonstrate how these devices would work, the researchers built a simple circuit that demonstrated Pavlovian learning—learning to associate one signal with another, like the sight of food with the ringing of a bell. The team also simulated how the devices would perform when combined to create a neural network, testing their ability to recognize handwriting.

Among the researchers’ next steps, Talin says, will be to build an array of these devices, to demonstrate their capabilities as a real-world neural network. They also plan to work on improving the speed of the device, which in this first demonstration took around 10 milliseconds to switch.

Mildred Dresselhaus, IEEE Medal of Honor winner, dies at 86

Mildred Dresselhaus, IEEE Medal of Honor Recipient Known as the "Queen of Carbon," Dies at 86

This week, the nanoscale withdrew from the larger world just a little. Mildred Dresselhaus, emerita professor of physics and materials science at MIT and Presidential Medal of Freedom winner (as well as IEEE Medal of Honor recipient), died on Monday at the age of 86.

Called the “Queen of Carbon Science,” Dresselhaus pioneered the study of carbon nanostructures at a time when studying physical and material properties of commonplace atoms like carbon was out of favor. Her visionary perspectives on the sixth atom in the periodic table—including exploring individual layers of carbon atoms (precursors to graphene), developing carbon fibers stronger than steel, and revealing new carbon structures that were ultimately developed into buckyballs and nanotubes—invigorated the field. 

“Millie Dresselhaus began life as the child of poor Polish immigrants in the Bronx; by the end, she was Institute Professor Emerita, the highest distinction awarded by the MIT faculty. A physicist, materials scientist, and electrical engineer, she was known as the ‘Queen of Carbon’ because her work paved the way for much of today's carbon-based nanotechnology,” MIT president Rafael Reif said in a prepared statement. 

Friends and colleagues describe Dresselhaus as a gifted instructor as well as a tireless and inspired researcher. And her boundless generosity toward colleagues, students, and girls and women pursuing careers in science is legendary.  

“Everything I do, I’m aware that Millie has her imprint on me,” said H. Eugene Stanley, director of the Boston University Center for Polymer Studies, when interviewed in 2015 for an IEEE Spectrum profile of Dresselhaus. “She’s unbelievably kind. She’s always helping everybody. She runs seminar series, big and little. And she’s a woman of high principles.” 

Professor Gang Chen, now head of MIT’s mechanical engineering department, recalls first meeting her in 1996. “At the time, I did not know anything on thermoelectrics, and I was surprised to hear she knew my name, maybe from many of her activities including knowing my Ph.D. advisor,” he said. “It was my first time writing a big proposal, and her beautiful handwriting (although difficult to read for me at the beginning) and careful editing of the proposal truly impressed me, even if I had not met her.  In 1997, I met her in person at UCLA during our MURI program kickoff meeting, where I moved to take an associate professor position.  She was so approachable, engaging in detailed scientific discussions, and caring.  These impressions only get reinforced more as our collaboration continues.”

In 1963, Dresselhaus began her own career studying carbon by publishing a paper on graphite in the IBM Journal for Research and Development, a foundational work in the history of nanotechnology. To this day, her studies of the electronic structure of this material serve as a reference point for explorations of the electronic structure of fullerenes and carbon nanotubes. Coauthor, with her husband Gene Dresselhaus, of a leading book on carbon fibers, she began studying the laser vaporation of carbon and the “carbon clusters” that resulted. Researchers who followed her lead discovered a 60-carbon structure that was soon identified as the icosahedral “soccer ball” molecular configuration known as buckminsterfullerene, or buckyball. In 1991, Dresselhaus further suggested that fullerene could be elongated as a tube, and she outlined these imagined objects’ symmetries. Not long after, researchers announced the discovery of carbon nanotubes. 

When she began her nearly half-century career at MIT, as a visiting professor, women consisted of just 4 percent of the undergraduate student population.  So Dresselhaus began working toward the improvement of living conditions for women students at the university. Through her leadership, MIT adopted an equal and joint admission process for women and men. (Previously, MIT had propounded the self-fulfilling prophecy of harboring more stringent requirements for women based on less dormitory space and perceived poorer performance.) And so promoting women in STEM—before it was ever called STEM—became one of her passions. Serving as president of the American Physical Society, she spearheaded and launched initiatives like the Committee on the Status of Women in Physics and the society’s more informal committees of visiting women physicists on campuses around the United States, which have increased the female faculty and student populations on the campuses they visit. 

Dresselhaus won many of the scientific and technical awards that an outstanding researcher in her field could have won, including the Kavli Prize, the Enrico Fermi Award, the IEEE Medal of Honor, the Medal of Science, the Presidential Medal of Freedom, and membership in the National Academy of Sciences and the National Academy of Engineering. 

As it happens, less than two weeks before her death, General Electric released a web video imagining a world in which Dresselhaus earned the celebrity and acclaim normally accorded to movie stars and musicians. “A Millie Dresselhaus doll!” a girl exclaims after she opens her birthday present, as a narrator asks, “What if we treated great female scientists like they were stars?” Dresselhaus, pausing to give strangers the opportunity to take a selfie with her, carries herself through the video with the warmth and gentle humor she showed throughout her remarkable life. 

“My first impression is like my last impression,” said Jean-Paul Issi, emeritus professor of physics at the Catholic University of Louvain, in Belgium, in a 2015 interview. “I was very impressed.” 

Specialized chips for energy-efficient AI

To Get AI in Everyday Gadgets, Engineers Go to Specialized Hardware

Thanks to an artificial intelligence technique called deep learning, computers can now beat humans at the Go game, identify melanomas as accurately as dermatologists do, and help autonomous vehicles navigate the world. Now, circuit designers are working on hardware they hope will lead to the democratization of deep learning, bringing the powerful method to the chips inside smart phones, wearables, and other consumer electronics.

Mobile phones, for example, will do a better job of understanding our individual accents and linguistic quirks. (This will save many of us from being constantly upset with a daft digital assistant. Right,Siri?) And home security systems will respond to the sound of a burglar breaking a window, but know not to alert the police when someone is clumsily emptying the dishwasher.

To that end, last week at the IEEE International Solid-State Circuits Conference (ISSCC) in San Francisco, academic and industry engineers showed how they have built on work presented at last year’s conference to produce specialized, energy efficient deep-learning processors. This dedicated hardware will give electronic devices a new level of smarts because, unlike traditional software, it relies on high-level abstraction like the human brain. What’s more, it won’t drain the gadgets’ batteries. “We’re beginning to see that there is a need to develop more specialized hardware to get both performance and energy efficiency,” says Mahesh Mehendale, TI Fellow at Texas Instruments in Bangalore. He co-chaired the conference session with Takashi Hashimoto, chief engineer in the technology development laboratory at Panasonic.

The first step to widespread adoption of deep learning is for companies to start marketing dedicated, low-power chips. For that reason, says Mehendale, the session’s entry from STMicroelectronics is significant. Like many projects of this sort, the company’s chip uses an architecture that brings memory and processing closer together. Compared to other algorithms, neural networks require frequent fetching of data; shortening the distance this data has to travel saves energy. Guiseppi Desoli, a researcher at STM’s Cornaredo, Italy, outpost, presented a neural network processor that can perform 2.9 trillion operations per second (teraops) per watt.

STMicroelectronics’ processor is designed to run algorithms called convolutional neural networks, which are used for image recognition. During his presentation, Desoli said the company believes neural networks can be incorporated into the Internet of Things—if designers can get power use down. “A normal battery will only last a few hours” when powering a deep-learning processor that can perform only a few teraops per watt, he said.

Hoi-Jun Yoo’s group at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, described a chip that pulls off a different feat. Not only is it more energy efficient than the one from STMicroelectronics (performing 8.1 teraops per watt), it can also run two kinds of neural networks. One, a convolutional neural network, is best for image recognition, because such networks excel at understanding information in photographs and other static images. The other, a recurrent neural network, can grapple with a sequence of information, because it remembers the previous input. Such networks are used for tasks like decoding speech; whether you’re listening or talking, you have to remember what was said a few seconds ago for a conversation to make sense.

Yoo’s group demonstrated a second deep-learning processor paired with an image sensor. The resulting gadget: a low-power, wearable badge that recognizes faces. This device relies on a specialized architecture that runs a convolutional neural network at 620 microwatts. That trickle of power is small enough for a coin cell battery to keep it running for more than 10 hours. In one demo, the KAIST system labeled photos with “Julia Roberts” and “pizza.” It can also spot Matt Damon, should the wearer ever come across him in person.

Another issue engineers delved into at ISSC was systems-level design. One way to save energy is to use low-power circuits to make initial decisions, then, when necessary, wake up relatively more power-hungry neural networks to do the heavy lifting. Anantha Chandrakasan’s lab at MIT presented a chip that uses a circuit to distinguish speech from other sounds. This circuit gates a neural network that can then recognize words. The MIT chip can perform tasks requiring a vocabulary of up to 145,000 words. It makes about one-fourth the number of word errors on a standardized test compared with the previous state-of-the-art system, while using about just one-third of the power of its predecessor.

The new chips presented last week, says Mehendale, show that “customized hardware is more efficient” for running neural networks. Training neural networks is another matter. Today, it must still be done on powerful computers. In coming years—perhaps next year—researchers will develop dedicated hardware for the deep learning training process, which will make that energy intensive process more efficient, says Panasonic’s Hashimoto.

A NIST employee in a safety vest examines a wireless experiment inside of a steam generation plant.

Factory Owners Are Reluctant to Embrace Wireless

If you think it’s hard to get a reliable Wi-Fi signal in your home, just imagine how tough it must be grab one atop an oil rig in the Gulf of Mexico, or on the noisy floor of an auto factory in Detroit. Those places are full of heat, vibration, and metallic surfaces that can weaken, reflect, and block signals. As a result, factories and industrial facilities have been slow to adopt new wireless equipment and devices that would otherwise save both time and money.

Many wireless engineers and factory owners know this, but it has been difficult for anyone to improve the situation. The impact of industrial settings on wireless performance hasn’t been studied in any systematic way, so it’s often impossible to predict how a new piece of equipment will perform on, say, a manufacturing line until you actually put it there.

To make it easier for factories to integrate new wireless technologies, U.S. federal government employees took it upon themselves to measure the performance of radiofrequency signals in three factory settings: an auto transmission assembly facility, a steam generation plant, and a small machine shop. They recently published their results as part of an ongoing $5.75 million project aimed at improving industrial wireless led by the National Institute of Standards and Technology (NIST).

For factory owners, there are many potential advantages to switching to wireless. They can avoid the costs and hassle of installing wires, and more easily reconfigure their facilities in the future. Wireless setups may also be safer, because employees won’t trip over bundles of cords. That’s why companies including GM, Ford, Chevron, Boeing, and Phoenix Contact (a company that specializes in industrial technologies) have all expressed interest in incorporating more wireless into these facilities.

“Right now I know that people are interested, but what they're worried about are the impacts to productivity or to the operation,” says Richard Candell, the project lead for the five-year NIST project, which is scheduled to conclude in late 2018. “They want to know that if they're going to use wireless, it's going to work just as well as the wired solution.”

Justin Shade, who focuses on wireless products for Phoenix Contact, says there’s no shortage of ways in which wireless could make factories and their workers more efficient. For example, manufacturers could use it to incorporate robotic arms into assembly lines. Today, robotic arms are often hooked up to control panels by flexible cables. Wind turbines rely on similar cables to maintain contact between the hub of the turbine and each individual blade. But these cables frequently break. In both cases, replacing them with wireless controls could save money and time.

Unfortunately, factories are also full of processes and materials that block or weaken wireless signals. For now, wireless technicians play it safe when installing new equipment by setting up redundancies, keeping wireless devices within close range with clear line of sight to their targets, and performing extensive testing prior to industrial installations.

Given the circumstances, Shade says it’s hard to fault factory owners and their technicians for being cautious. “If you're on the manufacturing line and a car door doesn't get made correctly, you're losing hundreds of thousands of dollars an hour, so the adoption has been a little slower in the industrial world,” he says.

Candell at NIST hopes their latest research can help industry operators predict how new systems will perform before they are installed. To take their measurements, the team visited an auto transmission assembly plant in Detroit, Mich., a steam generation plant at the NIST campus in Boulder, Colo., and a small machine shop that specializes in metalworking for NIST at their facilities in Gaithersburg, Md.

The group tested wireless signal propagation at two frequencies: 2.25 gigahertz and 5.4 GHz. These frequencies are reserved for the U.S. government, but fall close to the popular unlicensed 2.4-GHz and 5-GHz bands commonly used in wireless devices. Performance at these frequencies can therefore be considered comparable to what can be expected for wireless gadgets the rest of us use.

From their measurements, the researchers concluded that industrial settings have strong multipath characteristics, which means that signals tend to reflect many more times before they reach the receiver than they would under normal conditions. The practical impact of these reflections can be positive or negative, depending on the technology and how it is configured.

To dig deeper, the group used a metric to measure wireless performance called the K factor. It compares the combined power of all the reflected signals to the power of a line-of-sight signal with no reflections. A higher K factor means there is less fading due to reflections. In an open outdoor area, the K factor would typically be between 6 decibels and 30 dB. In the group's industrial measurements, they found lower average K factors of -5 dB to 6 dB.

Next, the NIST team used their measurements to estimate the average delay spread for the industrial facilities. Delay spread is the time it takes for all of a signal’s reflections to reach the receiver. They found an average delay spread below 500 nanoseconds. The group suggests this delay may not noticeably impact devices operating at 256 kilobits per second but could affect those that run at faster bit rates.

Another part of their analysis examined wireless performance in “metal canyons,” which are common in factories. A metal canyon is an area with metal surfaces (such as walls or large pieces of equipment) on at least two sides and a concrete floor below. In these areas, the group measured path loss, which describes the attenuation of wireless signals, and found that it is 80 dB, at a minimum, in metal canyons. For comparison, the path loss in an open area would be perhaps 40 dB after a signal at these frequencies traveled approximately one meter.

Candell says that, in practical terms, this means a wireless signal could reliably travel about 200 or 300 meters outdoors, whereas, in a metal canyon, a user would probably start to notice some issues with the signal at just 30 meters away. 

With the results of their measurement campaigns, the NIST staff also built a software simulation of a chemical reactor and a wireless test bed that can replicate other industrial settings at their campus in Boulder, Colo. Candell wants to use these tools to generate hypothetical changes in performance and cost related to installing new wireless schemes in factories or other facilities.

“Ultimately, at the end of our five-year project [which is scheduled to conclude in late 2018], I want to actually produce industry guidelines to help people select and deploy these wireless devices effectively in their factories,” says Candell.

A hiker in a yellow jack looks at her smartphone.

Controversial Satellite-Messaging Startup Higher Ground Cleared for Takeoff

In the face of concerted industry opposition, the Federal Communications Commission (FCC) has given the go-ahead for a controversial smartphone accessory that uses microwaves to send text messages and email via geostationary satellites.

Startup Higher Ground now has permission to deploy up to 50,000 SatPaq devices across the United States, promising isolated communities, hikers, and farmers a cheap, reliable messaging service far from cellphone towers. However, it is a move that some telecoms companies think could also interfere with their services, interrupt life-saving emergency calls and even cause outages nationwide. The roll-out will be a key test of the FCC’s ability to manage spectrum sharing, an innovation it is counting on to enable future 5G wireless and Internet of Things technologies.

The SatPaq devices, first revealed in Spectrum last year, connect to a smartphone messaging app via Bluetooth. The device uses a flip-up antenna that communicates with Intelsat Galaxy satellites in geostationary orbits. These are nearly 50 times further out than the Iridium satellites used by today’s satphones, so the SatPaq needs a powerful signal to connect.

It’s that strong signal—smack in the middle of the C-band microwave spectrum used for voice and data communications in rural areas and for national networks—that has many telecoms companies worried. In a submission to the FCC, CenturyLink called Higher Grounds’ plans “a recipe for disaster” and a “potential interference to each and every…link of the [microwave] network throughout the country.”

Its concerns were echoed by a dozen telecoms industry bodies and cities and states that rely heavily on point-to-point microwave stations for communications and emergency services. The state of Hawaii even wrote, “If this type of application is granted, the FCC itself becomes irrelevant. Commercial entities can simply do whatever pleases themselves.”

For its part, Higher Ground claims a robust system of ‘self-coordination’ that makes the chance of interference almost negligible. The SatPaq app starts by comparing the phone’s GPS coordinates with a database of the locations of all the terrestrial microwave stations in the country. It then selects a non-interfering frequency within its 5925 to 6425 MHz uplink band.

The app then uses the phone’s compass to ensure that the flip-up antenna is pointed directly at the satellite, and not towards a fixed station. If the system cannot find a safe combination of frequency and direction, it will not transmit. When the SatPaq does connect to the satellite, it will download any changes to its station database before transmitting its own data.

Last summer, Higher Ground conducted outdoor demonstrations of a live SatPaq embedded in a smartphone case to FCC officials and some of the telecoms companies, showing both the interference mitigation technology and the messaging service in action.

On 18 January, just 48 hours before the start of the new Presidential administration, the FCC ruled in Higher Ground’s favor. “We…find that Higher Ground’s proposed system and operations…would further the Commission’s interest in ensuring the highest public benefit is derived from this finite spectrum resource,” wrote the Commissioners. “We [also] find that Higher Ground has demonstrated that its proposed system should prevent or minimize the risk of harmful interference to [fixed service] operators.”

But the FCC did place conditions on Higher Ground’s operations. The company had to accept that existing microwave stations might interfere with its new messaging service, and is required to maintain remote control of all the SatPaqs in the country. If any interference comes to light, Higher Ground must be able to immediately override or shut down any or all interfering SatPaqs. The company also has to keep logs of every single SatPaq transmission for at least a year, and make that data available to the FCC and fixed service operators on request. Higher Ground also has to update its database of terrestrial microwave stations every day.

Finally, the FCC noted that “a cautious approach is warranted, considering that a self-coordination system like Higher Ground's does not have a track record of wide-scale, generalized deployment.” For the first year following authorization, Higher Ground can deploy only 5000 SatPaqs, and the FCC reserves the right to shut them down if they cause harmful interference.

“This is a prudent move for a unique technology,” says Steve Crowley, a consulting wireless engineer. “The phased rollout is an additional measure in case of unintended consequences. It’s easier to get a handle on 5,000 radios than 50,000.”

But Higher Ground’s battles may not be over just yet. The Enterprise Wireless Alliance, a national trade association for business wireless users, is considering filing a last-ditch appeal.

“At its core, this is an engineering matter and I think those engineering matters have been resolved to a reasonable level,” says Crowley. “But the Order was issued just before the start of the current FCC and only one of its three signers holds the same position as they did on January 18. A petitioner whose arguments didn’t prevail with the previous FCC might try again with this one.”

Higher Ground declined to comment on the FCC Order or any plans it might have to start selling SatPaqs. Its website, which previously suggested that SatPaqs would sell for US $139, with pay-as-you-go texts and emails, is currently offline.

5 Things You Missed This Week at IEEE Spectrum: Nanorods for Li-Fi Displays, Health Apps Could Make People Sicker, and More

1. Nanorods Emit and Detect Light, Could Lead to Displays That Communicate via Li-Fi

In recent years, the hot application for quantum dots has been as a replacement for light-emitting diodes (LEDs) as a backlight source for liquid crystal displays. But now, an international team of researchers has produced engineered nanorods that each feature a quantum dot capable of emitting and absorbing visible light. With this advance, quantum dots could someday yield mobile phones that can “see” without the need of a camera lens or communicate with each other using Light Fidelity (Li-Fi) technology.


2. Could Mobile Health Apps and Wearables Actually Make People Sicker?

A recent opinion piece about wearable tech for infants pulls no punches: “There is no evidence that consumer infant physiologic monitors are life-saving, and there is potential for harm if parents choose to use them.” That wasn’t just any random person’s judgement. The article was published in the Journal of the American Medical Association and was authored by two pediatricians and an expert from the ECRI Institute, a nonprofit organization dedicated to the rigorous evaluation of medical procedures and devices. 


3. Medtronic's CardioInsight Electrode Vest Maps Heart's Electrical System

The 252-electrode device could help doctors pinpoint the locations of electrical malfunctions in the heart that cause irregular heartbeats.


4. New Terahertz Transmitter Shines With Ultra-Fast Data Speeds

The tiny CMOS-based transmitter can send data packets wirelessly at rates as high as 105 gigabits per second.


5. Millimeter-Scale Computers: Now With Deep Learning Neural Networks on Board

University of Michigan micro-mote computers—tiny, energy efficient computing sensors that can do analysis on board—aim to make the Internet of Things smarter without consuming more power.

A millimeter-scale computer looks like a stack of chips

Millimeter-Scale Computers: Now With Deep-Learning Neural Networks on Board

Computer scientist David Blaauw pulls a small plastic box from his bag. He carefully uses his fingernail to pick up the tiny black speck inside and place it on the hotel café table. At 1 cubic millimeter, this is one of a line of the world’s smallest computers. I had to be careful not to cough or sneeze lest it blow away and be swept into the trash.

Blaauw and his colleague Dennis Sylvester, both IEEE Fellows and computer scientists at the University of Michigan, were in San Francisco this week to present 10 papers related to these “micromote” computers at the IEEE International Solid-State Circuits Conference (ISSCC). They’ve been presenting different variations on the tiny devices for a few years.

Their broader goal is to make smarter, smaller sensors for medical devices and the Internet of Things—sensors that can do more with less energy. Many of the microphones, cameras, and other sensors that make up the eyes and ears of smart devices are always on alert, and frequently beam personal data into the cloud because they can’t analyze it themselves. Some have predicted that by 2035, there will be 1 trillion such devices. “If you’ve got a trillion devices producing readings constantly, we’re going to drown in data,” says Blaauw. By developing tiny, energy-efficient computing sensors that can do analysis on board, Blaauw and Sylvester hope to make these devices more secure, while also saving energy.

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Illustration: iStockphoto

Four Ways to Tackle H-1B Visa Reform

U.S. tech companies love the H-1B visa program. The temporary visa is meant to allow them to bring high-skill foreign workers to fill jobs for which there aren’t enough skilled American workers.

But the program isn’t working. Originally intended to bring the best global talent to fill U.S. labor shortages, it has become a pipeline for a few big companies to hire cheap labor.

Giants like Amazon, Apple, Google, Intel, and Microsoft were all among the top 20 H-1B employers in 2014, according to Ron Hira, professor of political science at Howard University who has testified before Congress on high-skill immigration. The other fifteen—which include IBM but also consulting firms such as Tata Consultancy, Wipro, and Infosys—used the visa program mainly for outsourcing jobs.

Typically, U.S. companies like Disney, FedEx, and Cisco will contract with consulting firms. American workers end up training their foreign counterparts, only to have the U.S. firm replace the American trainers with the H-1B visa holding trainees—who’ll work for below-market wages.

Problems with this setup abound. First, talk of a tech labor shortage in the U.S. might be overblown. Then there’s the issue of quality: More than half of the H-1Bs at a vast majority of the top H-1B employers have bachelors degrees, but not advanced degrees. Hira argues that in many cases such as Disney and Northeast Utilities, the jettisoned American workers were obviously more skilled and knowledgeable than the people who filled those positions, considering the fact that they trained their H-1B replacements.

Plus, the H-1B is a guest-worker program where the employer holds the visa and isn’t required to sponsor the workers for legal permanent residency in the United States. So if the worker loses the job, he or she is legally bound to return to their country of origin. This gives the employer tremendous leverage, and can lead to abuse.

“It’s a lose-lose right now for the country and H-1B workers,” says Vivek Wadhwa, distinguished fellow and professor at Carnegie Mellon University Engineering at Silicon Valley.

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A tiny terahertz transmitter is mounted under a microscope in a lab at Hiroshima University.

New Terahertz Transmitter Shines With Ultrafast Data Speeds

This week, researchers at Hiroshima University showed off a new terahertz transmitter that is just as powerful as its predecessors, but should ultimately prove more affordable for commercial applications. In a demo at the International Solid-State Circuits Conference in San Francisco, they presented a device capable of delivering data at breathtaking speeds of more than 100 gigabits per second at a frequency of 300 gigahertz.

At its very best, the transmitter can shuttle data at 105 Gb/s, which is 2,100 times faster than the peak cellular speeds of 50 megabits per second available through LTE. After a successful demo, the transmitter could find its way into future wireless applications that require low latency and high bandwidth.

Though other transmitters have achieved speedy data rates in the terahertz range before, the group says theirs is the first to also be based on a CMOS integrated circuit, which means it’s potentially more viable for commercial base stations or devices.

“This is quite a step for this kind of technology, because it relies on something that is freely available and could be easily implemented, compared to all of the other techniques,” says Riccardo DegI’Innocenti, a researcher at the University of Cambridge who was not involved in the work.

Terahertz waves are shorter in length and are broadcast at much higher frequencies than the microwaves used today for smartphones, household devices, or military radar. For example, Wi-Fi devices emit waves that measure about 12 centimeters in length at a frequency of 2.4 GHz. Waves in the terahertz range span less than 1 millimeter and start at 100 GHz.

Other teams have demonstrated competing terahertz transmitters that deliver data at speeds even faster than those shown by the Hiroshima group. However, these systems often relied on technology that was bulky or which could not easily scale.

In contrast, the new transmitter has a 2-by-3-mm footprint, and was created using a 40-nanometer CMOS process. “There are many ways also to build a terahertz wireless system,” says DegI’Innocenti. “However, this is still progress because the CMOS technology was sort of lagging behind.”

Minoru Fujishima, a professor at Hiroshima University and a member of the team that developed the transmitter, says the primary advantage of fabricating the device with CMOS is that it will allow manufacturers to sell it at a competitive price if it is commercialized. However, the first run was still rather expensive. The tiny transmitter he demonstrated cost US $100,000 to build.

Fujishima’s group hopes their transmitter can be used in satellite communications, or to set up a wireless link between cellular base stations. “I think that is a very promising application because space cannot be linked by fiber optics,” he says.

Elsewhere, companies and researchers have developed extra-sensitive receivers to reliably detect terahertz waves, which are quickly absorbed as they travel through the atmosphere.

Thomas Küerner, who has worked at TU Braunschweig in Germany on projects in which terahertz transmitters have been developed, calls the new research “quite a milestone.” Alongside Iwao Hosako, who is a coauthor with Fujishima, Küerner is leading the IEEE 802.15 Task Group 3d; the group’s mission is to develop a standard for devices that will operate in the 300-GHz band.

Küerner says the task group is considering four primary applications for 300-GHz devices. One is as a replacement for the wires inside devices with high-speed terahertz links that can send data from one part of the device to another. The second is using terahertz waves to enable the creation of wireless kiosks in retail stores that will let customers instantly download films to their devices instead of having to take a DVD home with them. The third, says Küerner, is to create wireless connections for data centers that can replace fiber optic cables. And the final application is to use terahertz waves for fronthaul or backhaul in cellular networks.


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