Tunneling Electrons Do Math

first_imgIn brief, here’s how it works: The value of charge reservoir Q is reset to zero before each computation, and electrons tunnel from Q to reservoir Q x D, one at a time, until the value of reservoir Q x D equals that of reservoir Z. The final answer to the problem is the value of reservoir Q; since removing electrons increases the value of the reservoir, this is a positive value. The researchers improved this simple but limited design by transferring electrons in groups using a “building blocks” method, which decreased unwanted delay and could calculate a remainder. In reservoir Q, electrons are grouped in blocks in logarithmic numbers (e.g. in groups of 1, 2, 4, 8, etc.). An electron block estimates if its transfer would cause the value of reservoir Q x D to exceed that of reservoir Z. If so, the electron block is not transferred, and the next smaller electron block evaluates the same condition. For example, for 22 divided by 4, one block of 4 electrons, zero blocks of 2 electrons, and one block of 1 electron are transferred to create a positive charge of 5 in reservoir Q. The remainder is calculated with a subtraction block, which evaluates the difference between the values of reservoirs Z and Q x D (in this case, 22-20=2).The researchers’ third scheme is fine-tuned further, and is based on the computation of periodic symmetric functions (PSF). A PSF block based on an electron trap has a periodic transfer function, of which the period can be dynamically adjusted by using a voltage controlled capacitor. A device called a varactor would be used in place of a capacitor, which is currently still theoretical for the nanoscale. The PSF scheme resulted in the best performance out of the three schemes, with a worst-case delay of 18 ns and a worst-case energy consumption of 2.3 eV. Meenderinck explained that an accurate comparison to CMOS is difficult, but to give an idea of the difference, he looked at a recent publication on CMOS dividers (‘Low Power Self-Timed Radix-2 Division,’ Jae-Hee Won and Kiyoung Choi, ISLPED, 2000). “We calculated a delay of 18 ns and an energy consumption of 3.7e-19 J,” he said. “The scheme of Won and Choi has a delay of 33.8 ns and an energy consumption of 3.4e-9 J. Clearly, the energy consumption is the key benefit of our SET circuit. Considering that power has become one of the main design constraints, SET becomes a serious candidate for the post-CMOS era.”Meenderinck also added that, although the latency of the two circuits does not appear to differ much, that number could change when using alternative equations. “We used the equations of the orthodox theory, which is generally accepted by the research community in the field,” he said. “However, there are some researchers (mainly from the circuit theory area) that disagree with this theory. For example, J. Hoekstra proposed a circuit theory (‘On the impulse circuit model for the single-electron tunnelling junction,’ International Journal of Circuit Theory and Applications, 2004) in which the delay is calculated as the RC product of the circuit. Using this theory, the delay we report would be much smaller—reduced by a factor of 100 or more.”For engineers who use SET to look beyond traditional ways of computation, Meenderinck and Cotofana predict that the technique has the potential to make many such improvements in future computing.Citation: Meenderinck, Cor and Cotofana, Sorin. “Computing Division Using Single-Electron Tunneling Technology.” IEEE Transactions on Nanotechnology, Vol. 6, No. 4, July 2007.Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Researchers develop new way to measure fluid-rock interaction in oil reservoir Using a novel computing paradigm involving counting single electrons, computer engineers have designed nano-sized circuitry that allows tunneling electrons to perform mathematical division calculations. Explore further Citation: Tunneling Electrons Do Math (2007, August 2) retrieved 18 August 2019 from https://phys.org/news/2007-08-tunneling-electrons-math.html While other methods utilizing quantum mechanical behavior have been proposed to increase computing power, these technqiues have yet to take full advantage of quantum mechanical properties on the nanoscale—namely, high speed and low power consumption.Cor Meenderinck, a PhD student in Computer Engineering, and Sorin Cotofana, an Associate Professor in Computer Engineering, from the Delft University of Technology in the Netherlands, have recently published their research on a quantum mechanical behavior called single-electron tunneling (SET) in IEEE Transactions on Nanotechnology. Building on their past SET paradigms that perform addition and multiplication operations, Meenderinck and Cotofana have presented three schemes that use tunneling electrons to quickly divide.Electron tunneling is a phenomenon on the quantum scale that enables single electrons to “jump” across forbidden energy states due to their wave-like properties. A few scientists have recently been experimenting with SET circuits based on tunnel junctions that consist of a thin insulating material layered between conducting material. Although charge transport across an insulator is prohibited in classical mechanics, electrons can tunnel one at a time through an ultrathin insulator in quantum mechanics. Electrons can represent bits, making SET a potential candidate to succeed CMOS technology.“As far as we know, very few people have been designing circuits with SET and we are not aware of any division implementations,” Cotofana told PhysOrg.com. “Thus comparison is limited to CMOS. Our circuits basically compute analog values. However, due to the discreteness of electrons (if the circuit is designed properly, an electron tunnels or not and electrons are localized on either side of the junction) we end up with digitized values; that is, the number of electrons present in a reservoir is the represented value.”Meenderinck’s and Cotofana’s first SET design to perform division was based on a sequential approximation of the quotient. The scheme uses electron counting, with three charge reservoirs that store electrons for the dividend Z, quotient Q, and product of Q and the divisor D (Q x D). last_img read more

Read More →

Mamata lashes out at Centre for trying to curb freedom of Press

first_imgKolkata: Criticising the Centre’s step to “curb freedom of Press” in the name of controlling fake news as a “draconian move”, Chief Minister Mamata Banerjee has demanded immediate withdrawal of the circular of suspending or cancelling accreditation of journalists.Banerjee tweeted: “The PIB circular on #FakeNews control is a brazen attempt to curb Press freedom, a sure sign that the Govt has lost its way. We demand the immediate withdrawal of such a draconian move.” Also Read – Heavy rain hits traffic, flightsIn the tweet, she also took a dig at BJP, without taking its name, in connection with the circulation of fake news: “And what about #FakeNews spread by a political party on a regular basis?”It may be recalled that the Chief Minister was the first to raise her voice against circulation of fake news, mainly through social media, to purposely create trouble. She had repeatedly urged people to ignore such news and also directed the police to maintain a vigil so that such news doesn’t get circulated.It may be mentioned that when allegations of attempting to curb freedom of journalists rose against the Centre, the Mamata Banerjee government has issued a notification to give pension to journalists above 60 years as a “respect and responsibility of the state on democracy”.The Centre was forced to withdraw the move in the wake of severe criticism.last_img read more

Read More →

Physical fitness may boost kids academic performance

first_imgChildren who go in for physical fitness may possess a greater volume of gray matter that may help enhance their academic performance, reveals a new finding. Physical fitness especially cardiorespiratory fitness, speed-agility and muscular fitness, leads to the presence of more gray matter in the brain.Increase in grey matter in various regions of the brain boosts learning, functioning and reading processes of the child, the researchers said, in the paper published in the journal Neuroimage. Also Read – Add new books to your shelf”Our work aims at answering questions such as whether the brain of children with better physical fitness is different from that of children with worse physical fitness and if this affects their academic performance,” said a researcher at the University of Grenada in Spain.”The answer is short and forceful: yes, physical fitness in children is linked in a direct way to important brain structure differences, and such differences are reflected in the children’s academic performance,” Ortega added.”Physical fitness is a factor that can be modified through physical exercise, and combining exercises that improve the aerobic capacity and the motor ability would be an effective approach to stimulate brain development and academic performance in overweight/obese children.”last_img read more

Read More →

More Than 150000 US SmallBusiness Websites Could Be Infected With Malware at

first_img Attend this free webinar and learn how you can maximize efficiency while getting the most critical things done right. June 12, 2019 It was March 2, 2016, and Melissa Marchand’s day on Cape Cod started out like any other. She drove to her job at Hyannis Whale Watcher Cruises in her mid-size sedan, picked up a latte with 1 percent milk at her local coffee shop and sat down at her desk to check her email. Then, Marchand got the call no website manager ever wants to receive: The site was down, and no one knew how to fix it.After she dialed up the web hosting provider, the news went from bad to worse: Whales.net had been hacked and, to her horror, all visitors were being redirected to porn sites. Google had even flagged the company’s search results, warning potential customers that the site may be hacked.“It was a total nightmare — I had no idea that something like this could happen,” Marchand said in an interview with Entrepreneur. “I’d say 75 to 80 percent of our bookings are done online, so when our site is down, we’re just dead in the water.”At the provider’s suggestion, Marchand called SiteLock, a website security company, and granted its representatives site access. SiteLock discovered the hackers had exploited a security hole in a WordPress plugin, which gave them the access they needed to redirect visitors to racy websites.By the end of the work day, Marchand sat in her car in her gym’s parking lot, speaking on the phone with a SiteLock representative to review the plan of action. She finally felt like things were going to be OK.Within three days, Whales.net was back up and running, though it took another three weeks for Google to remove the blacklist warning from the company’s search results.The hack hit about a month before the whale-watching season began in mid-April, and though it wasn’t peak season, the company still missed out on pre-booking tour groups from schools and camps. Marchand estimated the attack lost the company about 10 percent of its March and April business.A risk for small businesses everywhereSmall-business owners were victims in 43 percent of data breaches tracked between Nov. 1, 2017, and Oct. 31, 2018, according to a 2019 Verizon report. The report tracked security incidents across all industries, but the most vulnerable sectors this year were retail, accommodation and healthcare.What does the issue look like on a national scale? If we take the sample size of infected sites SiteLock said they found in 2018 — approximately 47,244 out of 6,056,969 checked — and apply that percentage to the country’s estimated 30.2 million small-businesses websites, minus the estimated 36 percent that don’t have one, then we can loosely estimate the amount of infected small-business websites to be around 150,757.As a small-business owner, you may not believe anyone would target your website, but that’s just it — bad actors are likely not seeking out your site specifically, said Mark Risher, head of account security at Google.“Sometimes, we talk about the distinction between targets of choice and targets of chance,” Risher said. “Targets of chance is when the attacker is just trying anything — they’re walking through the parking lot seeing if any of the car doors unlocked. Target of choice is when they’ve zeroed in on that one shiny, flashy car, and that’s the one they want to break into — and they’ll try the windows, the doors … the moon roof. I think for small businesses, there’s this temptation to assume, ‘No one would ever choose me; therefore I’ll just kind of skate by anonymously.’ But the problem is they’re not factoring in the degree of automation that attackers are using.”Even the least-trafficked websites still average 62 attacks per day, according to SiteLock research. “These cybercriminals are really running businesses now,” said Neill Feather, president of the company. “With the increasing ease of automation of attacks, it’s just as lucrative to compromise a 1,000 small websites as it is to invest your time and try to compromise one large one.”John Loveland, a cybersecurity head at Verizon and one of the data breach report’s authors, said that since the report was first published 12 years ago, he’s seen a definite uptick in attacks at small and medium-sized businesses. As malware, phishing and other attacks have become “more commoditized and more readily accessible to lesser-skilled hackers,” he said, “you see the aperture open … for types of targets that could be valuable.”So what are the hackers getting out of the deal? It’s not just about potentially lucrative customer information and transaction histories. There’s also the opportunity to weaponize your website’s reputation. By hosting malware on a formerly trustworthy website, a hacker can increase an attack’s spread — and amplify the consequences — by boosting the malware’s search engine optimization (SEO). They can infect site visitors who search for the site organically or who access it via links from newsletters, articles or other businesses, Risher said.Even if you outsource aspects of your business — say, time and expense reporting, human resources, customer data storage or financial transactions — there’s still no guarantee that that information is safe when your own website is compromised. Loveland said he saw an uptick in email phishing specifically designed to capture user credentials for web-based email accounts, online CRM tools and other platforms — and reports of credential compromise have increased 280 percent since 2016, according to an annual survey from software company Proofpoint.How to protect yourself and your customersHow can small-business owners protect themselves — and their customers? Since a great deal of cyberattacks can be attributed to automation, putting basic protections in place against phishing, malware and more can help your site stay off the path of least resistance.Here are five ways to boost your small-business’s cybersecurity.1. Use a password manager.There’s an exhaustive amount of password advice floating around in the ether, but the most important is this, Risher said: Don’t reuse the same password on multiple sites. It’s a difficult rule to stick to for convenience’s sake — especially since 86 percent of internet users report keeping track of their passwords via memorization — but cybersecurity experts recommend password managers as efficient and secure workarounds. Free password manager options include LastPass, Myki and LogMeOnce.2. Set up email account recovery methods to protect against phishing attacks.Phishing attacks are an enduring cybersecurity problem for large and small businesses alike: 83 percent of respondents to Proofpoint’s annual phishing survey reported experiencing phishing attacks in 2018, an increase from 76 percent the year before. Embracing a more cyber-aware culture — including staying vigilant about identifying potential phishing attacks, suspicious links and bogus senders — is key to email safety.If you’re a Gmail user, recent company research suggests that adding a recovery phone number to your account could block up to 100 percent of cyberattacks from automated bots, 99 percent of bulk phishing attacks and 66 percent of targeted attacks. It’s helpful because in the event of an unknown or suspicious sign-in, your phone will receive either an SMS code or an on-device prompt for verification. Without a recovery phone number, Google will rely on weaker challenges such as recalling last sign-in location — and while that still stops most automated attacks, effectiveness against phishing drops to 10 percent.3. Back up your data to protect against ransomware.Ransomware — a cyberattack in which a hacker holds your computer access and/or data for ransom — has kicked off a “frenzy of cybercrime-related activities focused on small and medium businesses,” Loveland said. In fact, it’s the second leading malware action variety in 2019, according to the Verizon report, and accounted for 24 percent of security incidents. Hackers generally view it as a potentially low-risk, high-reward option, so it’s important to have protections in place for such an attack — namely, have your data backed up in its entirety so that you aren’t at the hacker’s mercy. Tools such as Google Drive and Dropbox can help, as well as automatic backup programs such as Code42 (all charge a monthly fee). You can also purchase a high-storage external hard drive to back everything up yourself.4. Enlist a dedicated DNS security tool to block suspicious sites.Since computers can only communicate using numbers, the Domain Name System (DNS) is part of the internet’s foundation in that it acts as a “translator” between a domain name you enter and a resulting IP address. DNS wasn’t originally designed with top-level security in mind, so using a DNSSEC (DNS Security Extension) can help protect against suspicious websites and redirects resulting from malware, phishing attacks and more. The tools verify the validity of a site multiple times during your domain lookup process. And though internet service providers generally provide some level of DNS security, experts say using a dedicated DNSSEC tool is more effective — and free options include OpenDNS and Quad9 DNS. “[It’s] a low-cost, no-brainer move that can prevent folks from going to bad IP addresses,” Loveland said.5. Consider signing up with a website security company.Paying a monthly subscription to a website security company may not be ideal, but it could end up paying for itself in terms of lost business due to a site hack. Decreasing attack vulnerability means installing security patches and updates for all of your online tools as promptly as possible, which can be tough for a small-business owner’s schedule.“It’s tempting for a small-business owner to say, ‘I’m pretty handy — I can do this myself,’” Risher said. “But the reality is that even if you’re very technical, you might not be working around the clock, and … you’re taking on 24/7 maintenance and monitoring. It’s certainly money well spent to have a large organization doing this for you.” Free Webinar | Sept 5: Tips and Tools for Making Progress Toward Important Goalscenter_img Register Now » 9 min readlast_img read more

Read More →