Month:

August 2019

Skyrmion reshuffler comes to the aid of stochastic computing

first_img Explore further One of the main advantages of stochastic computing is its error-tolerance. If one bit in a string becomes flipped, then in the traditional computing scheme that minor error completely changes the value of the encoded data. In stochastic computing, however, a flipped bit only slightly changes the probability of finding a 1, and in a sufficiently long bitstream the effect is negligible. This advantage becomes especially important when electronic devices are scaled down to the point where errors become more frequent, resulting in the need for error-correcting codes in traditional computing.A stochastic computing device can perform arithmetic with p-values, but, due to the way these calculations are implemented, the device often does not give the correct answer when the two input bitstreams are identical—that is, when they have the same 0’s and 1’s in exactly the same order. To address this problem, the signals must be reshuffled while conserving the p-values. Although reshuffling signals can be done using pseudo-random number generators, these require large memories and consume large amounts of energy. The skyrmion reshuffler uses orders of magnitude less memory and energy than these devices, suggesting that it may offer a low-energy, high-efficiency solution to this problem. Skyrmion neuronThe researchers also showed that, with some modifications, the skyrmion reshuffler can function similarly to a biological neuron. When a neuron receives electrochemical signals from other neurons, it integrates the incoming activity and, if the activity is sufficiently high, it sends out a voltage spike of its own. Neurons are also “leaky” in the sense that, when they do not receive signals, their voltage slowly decays over time.Similarly, when the “skyrmion neuron” receives a bitstream of skyrmions as input, it accumulates the skyrmions in one of its chambers, and then sends out a reshuffled bitstream. Moreover, when skyrmions are crammed together too tightly, they begin to annihilate, emulating a leaky neuron.The researchers expect that both the skyrmion reshuffler and skyrmion neuron may one day serve as the building blocks of future spintronic stochastic computers. “The skyrmion reshuffler is actually a very versatile device,” Pinna said. “On top of reshuffling telegraph noise signals (or, equivalently, bitstreams), it can also be used to generate bitstreams with well-defined p-values. In fact, by injecting skyrmions in specific ratios in the device’s two chambers, the device effectively takes an imposed p-value as input and outputs a scrambled stream of skyrmions defining it. Although this is probably more efficient to implement with super-paramagnetic tunnel junctions, it does turn out to be pretty elegant that the same device can be used to both scramble and generate random bitstreams. “The skyrmion neuron is a smaller tassel in the big picture of neuromorphic techniques in magnetism. It is of great interest to study all the ways we can functionally reproduce a neuron’s behavior in condensed matter systems. The philosophy behind it is that one can then attempt to construct analog neural networks bottom-up by coupling many such elements together.” A stochastic computing device multiplies the p-values of two input signals using an AND gate. (a) The result is accurate when the two signals are not correlated, but (b) inaccurate when the signals are correlated. (c) After the signals have been reshuffled, they are no longer correlated but still have the same p-value, resulting in a better approximation. Credit: Pinna et al. ©American Physical Society Stochastic computingIn traditional computing, data is encoded as an ordered string of 0’s and 1’s, and operations are performed on the data by precisely manipulating these binary digits. In stochastic computing, on the other hand, data is encoded in bitstreams of random 0’s and 1’s where the order does not matter. Instead, the important thing is that the probability of finding a 1 in any given position in the bitstream, i.e., the p-value, corresponds to the value of the data being encoded. Researchers have designed a “skyrmion reshuffler”—just as a card shuffler shuffles a deck of cards, the skyrmion reshuffler does the same with a type of quasiparticle called magnetic skyrmions. The reshuffler is the first low-energy, compact device that can reshuffle signals of any kind (skyrmions, electrons, etc.) with a high efficiency, which may enable it to address one of the long-standing challenges facing an alternative type of computing called stochastic computing. 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. More information: D. Pinna et al. “Skyrmion Gas Manipulation for Probabilistic Computing.” Physical Review Applied. DOI: 10.1103/PhysRevApplied.9.064018Also at arXiv:1701.07750 [cond-mat.mes-hall]center_img © 2018 Phys.org The basic concept of the skyrmion reshuffler: skyrmions are injected into a chamber, manipulated, and read out. Credit: Pinna et al. ©American Physical Society Meet the skyrmions—exotic quasiparticles could revolutionise computing The researchers, Daniele Pinna and coauthors from the University of Paris-Saclay, have published a paper on the new method of manipulating skyrmions for stochastic computing in a recent issue of Physical Review Applied.Skyrmions in two dimensionsMagnetic skyrmions are tiny defects in a magnetic field where the magnetic field is reversed. One of their interesting properties is their ability to move freely along the two-dimensional surface of the magnetic field. When many skyrmions come together, their high mobility causes them to act as a freely moving gas in two dimensions. In recent years, magnetic skyrmions have captured the attention of researchers because their tiny size (roughly 10 nm) and high mobility suggest that they have the potential to serve as information carriers for future miniaturized, high-speed, low-energy devices. So far, however, most of the work in the emerging field of skyrmionics has used skyrmions in one-dimensional tracks, rather than taking advantage of their full two-dimensional freedom.The skyrmion reshuffler presented in the new study is one of the first devices to harness the dynamics of skyrmions as a two-dimensional gas. The reshuffler receives an input stream of skyrmions and thermally reshuffles their order, while still maintaining the same skyrmion states as in the original stream. That is, if the skrymions were encoding data using 0’s and 1’s, then both the input and output bitstreams would have the same number of 0’s and 1’s. Consequently, the probability of finding a 1 (referred to as the p-value in this context) would be the same in either bitstream, meaning that the p-value is conserved. As it happens, reshuffling while conserving p-values is exactly what’s needed to perform certain operations using an alternative type of computing called stochastic computing. “The greatest significance of this work is, in my opinion, having rid skyrmions from the 1-D shackles they have been forced to live in,” Pinna told Phys.org. “At every magnetism conference, research work on skyrmions preambles with their potential use for racetrack memory applications. [But] skyrmions are intrinsically 2-D objects with extremely interesting mobility and spatially extended properties. My work (past and current) attempts to design, theorize and demonstrate novel devices in the realm of unconventional computing where I firmly believe that nanomagnetism and spintronics can pave the way for the development of scalable and energy-efficient analog computational devices.” Citation: Skyrmion reshuffler comes to the aid of stochastic computing (2018, July 6) retrieved 18 August 2019 from https://phys.org/news/2018-07-skyrmion-reshuffler-aid-stochastic.htmllast_img read more

New Research From Clinical Psychological Science

first_imgWeaker Memory Performance Exacerbates Stress-Induced Cannabis Craving in Youths’ Daily LivesRobert Miranda, Jr., Stephanie E. Wemm, Hayley Treloar Padovano, Ryan W. Carpenter, Noah N. Emery, Joshua C. Gray, and Ethan H. Mereish Heterogeneity of the Anxiety-Related Attention Bias: A Review and Working Model for Future ResearchTracy A. Dennis-Tiwary, Amy Krain Roy, Samantha Denefrio, and Sarah Myruski The Influence of Stress on Depression and Substance Use Problems Among Young Male Same-Sex Couples: Relationship Functioning as an Underlying MechanismBrian A. Feinstein, Elizabeth McConnell, Christina Dyar, Brian Mustanski, and Michael E. Newcomb Read about the latest research published in Clinical Psychological Science: Most of the past research on suicidal thoughts and behaviors (STBs) relied on long follow-ups and examined risk factors in isolation when predicting suicide is more complex. To address whether these methodological constraints have the ability to predict suicide risk, the researchers recruited a large sample of individuals worldwide who were at elevated risk of STBs, evaluating them in a first session and again 3, 14, and 28 days later. The researchers also used machine-learning algorithms to examine the complexity underlying suicide risk. Results indicated that machine-learning algorithms were better than individual follow-ups at predicting STBs. Some predictive factors such as suicide ideation, were already strong predictors in more standard analyses, but complex models in this research were a way to better predict imminent suicidal thoughts and nonfatal suicide attempts. Taken together, these findings support the use of complex models and inclusion of artificial intelligence in clinical decision making. This study examined the interaction of stress, reminders of cannabis use, and craving for the drug among adolescents and young adults. Miranda and colleagues recruited participants who used cannabis at least twice weekly and reported at least one symptom of cannabis abuse. At the beginning of the study, participants performed a memory-for-words test that captured working memory performance.  Then, over 4 to 14 days, they were prompted on their mobile devices every 3 hours to report their cannabis cravings, consumption, current levels of stress, and presence of cannabis-related stimuli in their environment (e.g., presence of drug paraphernalia, interactions with people they frequently smoked marijuana with). Individuals reported stronger craving in the evenings and late night relative to the morning, in the presence of other cannabis-related stimuli, and when experiencing more interpersonal stress. Importantly, individuals with weaker working memory performance experienced stronger craving when their stress was heightened than individuals with stronger working memory performance. However, working memory performance did not affect the association between cannabis-related stimuli and craving. These findings indicate that stronger working memory may protect individuals from craving cannabis at stressful moments. Predicting Imminent Suicidal Thoughts and Nonfatal Attempts: The Role of ComplexityJessica D. Ribeiro, Xieyining Huang, Kathryn R. Fox, Colin G. Walsh, and Kathryn P. Linthicum To examine the associations between stress and health (including depression and substance use) among male same-sex couples, Feinstein and colleagues analyzed data from an ongoing longitudinal study on HIV and substance use among gay, bisexual, and other men who have sex with men. Participants completed measures of perceived stress, internalized stigma (e.g., fear of coming out), microaggressions (e.g. someone expressing a stereotype, such as “Gay men are so good at fashion”), victimization (e.g., being physically assaulted), outness, depression, alcohol-use problems, marijuana-use problems, and relationship functioning (i.e., satisfaction, trust, and commitment). Results indicated that when a member of the couple reported internalized stigma and microaggressions, relationship interactions were more negative and were linked with greater depression and alcohol abuse. These findings suggest that individual stress might increase conflict within a relationship. Results also highlight the importance of considering general stress as a risk factor for negative health outcomes among male same-sex couples. Relationship education and interventions focused on sexual minority individuals and same-sex couples may be enhanced by showing them strategies to cope with stress and understand how their relationship quality influences health, Feinstein and colleagues propose. Anxiety-related attention bias (AB) is characterized by selective or exaggerated attention toward threatening information and seems to be a concept with different aspects and with complex relationships with anxiety. In this review, Dennis-Tiwary and colleagues propose a working model of AB that incorporates subtypes and variability. They say AB should no longer be considered solely a tendency to focus attention on a threat instead of away from it. Behavioral and neurophysiological research indicates, for instance, that AB toward threat is associated with distress-related disorders, such as generalized anxiety disorder. Meanwhile, AB away from threat is associated with fear-related disorders, such as phobias. According to this threat-discrimination and cognitive-control model of AB, four subtypes of AB heterogeneity can be identified: (a) labile, characterized by low threat-safety discrimination (TD; ability to discriminate between safe and threatening cues) and low cognitive control (CC), with high variability in AB; (b) vigilant, characterized by high TD and low CC, with a bias toward threatening information; (c) avoidant, characterized by high TD and high CC, with a bias away from threatening information; and (d) no bias, characterized by low TD and high CC. The authors propose that this model can lead to personalized interventions for anxiety disorders, with treatment tailored to an individual’s AB subtype.last_img read more

Dancing for a world celebration

first_img‘Dancing is the poetry of the foot’ as per John Dryden’s perspective of the orb of dance, that has been the key philosophy and inspiration for India’s eminent danseuse Geeta Chandran and her lovechild – Natya Vriksha – the perfect platform for her abundant, dedicated passion and ability to nurture and harness talent, that firmly establish Indian dance traditions. On the occasion of the 9th World Dance Day Chandran celebrated the charming nuances of Indian dance traditions, paying homage to the dance community with a showcase of several avtaars at the India International Centre Auditorium. Also Read – ‘Playing Jojo was emotionally exhausting’Organised in collaboration with the Ministry of Culture and India International Centre, with additional support from the Sangeet Natak Akademi, NTPC and UNESCO, Natya Vriksha’s World Dance Day 2013 celebration offered the capital’s cultural aficionados, an assured opportunity for enjoying Geeta Chandran’s ‘Young Dancers’ Festival’ – a successful endeavour to create new spaces for the contemporary classical dancer, forming new frontiers of classical art, to reach out to new, young, audiences, believing and asserting that dance must be linked to life at the grass root level and that artists must make a positive difference to real living.Indeed, Geeta Chandran’s World Dance Day calendar resonates in spirit –  Martha Graham’s sensibility that ‘Dancers are the messengers of the gods’.last_img read more

For the love of cinema

first_imgThe second edition of Dharamshala International Film Festival- DIFF, was announced in the Capital on Tuesday. For all the cinema lovers this year DIFF has an array of 30 films – a choice pick from independent movies, documentaries, short films and experimental cinema.Created by noted filmmakers Ritu Sarin and Tenzing Sonam this film festival is determined to provide a platform to independent movie makers and to present exceptional contemprory cinema to the viewers.  Also Read – ‘Playing Jojo was emotionally exhausting’Few movies to be screened this year includes Mike Lerner and Maxim Pozdorovkin’s provocative Pussy Riot: A Punk Prayer, based on controversy created by  the Russian feminist punk rock protest group. Another interesting watch will be  Polish filmmaker Jacek Borcuch’s award-winning romantic feature film, Lasting which will be followed by Australian director Kate Shortland’s moving post-World War II drama, Lore; British artiste Shezad Dawood’s debut sci-fi feature, Piercing Brightness and Japanese cult director Takanori Tsujimoto’s martial arts extravaganze, Bushido Man. Also Read – Leslie doing new comedy special with NetflixThis year, DIFF have a special focus on Indian documentaries with strong social concerns. Festival will be presenting Nishtha Jain’s Gulabi Gang, Amit Virmani’s Menstrual Man, and Anand Patwardhan’s Jai Bhim Comrade.A number of films selected for the festival are based on children or teenagers struggling to overcome failure and dilemmas are also lined up. Some of these are Kim Mordaunt’s coming-of-age drama set in Laos, The Rocket; Dominga Sotomayor’s Chilean road movie, Thursday Till Sunday. Following the new Indian Indie wave, films like Nagraj Popatrao Manjule’s Fandry and Q’s Tasher Desh will also be screened.A carefully curated series of fillers (to be screened between movies) will present short takes  made by leading international artistes.last_img read more

IS blows up Syria gas pipeline Monitor

first_imgJihadists from the Islamic State group blew up a pipeline feeding natural gas from eastern Syria to the suburbs of the capital Damascus early today, a monitor said.The Syrian Observatory for Human Rights said IS blew up the pipeline near the T-4 military airport in the east of central Homs province shortly after midnight. “This pipeline was used to carry gas into the suburbs of Damascus and Homs to generate electricity and provide heating in individual homes,” said Observatory head Rami Abdel Rahman. Also Read – Pro-Govt supporters rally as Hong Kong’s divisions deepenIS has seized a number of oil and gas fields in Homs province, most recently during its offensive on the ancient city of Palmyra. These fields were key to Syria’s embattled regime, which relied on them for power generation in its dwindling areas of control. “Any hit to the regime’s gas supply is important, because its resources are very low,” Abdel Rahman said.While IS has made use of oil fields it has captured to generate income, processing natural gas is much trickier, according to Yezid Sayigh, an analyst at the Carnegie Middle East Centre in Beirut.Blowing up gas pipelines demonstrates that “the name of its game for now is denial of key resources to the regime,” Sayigh wrote recently.last_img read more

Scattered rainfall in city humidity soars

first_imgScattered showers were witnessed in parts of the national Capital on Monday which failed to bring any respite from the humid weather conditions that Delhiites have been facing since the past few days.The maximum temperature on Monday was recorded at 34.7 degrees Celsius which was a notch above the season’s average while the minimum temperature had settled at 24.6 degree Celsius, two notches below the normal.“Areas under Palam, Lodhi Road and Ayanagar received 0.8 mm, 1.2 mm and 1.3 mm rainfall between 8.30 am and 5.30 pm. Also Read – Company director arrested for swindling Rs 345 crore“Safdarjung observatory, reading of which is considered the official figure for the city and areas under Ridge did not record any rainfall in the same period,” a MeT department official said.Humidity level oscillated between 61 and 87 per cent.The MeT department has predicted generally cloudy sky with a possibility of light rains and thunder storm in many parts of the city on Tuesday.last_img read more

Expedite hostel renovation Education Min urges Lohia

first_imgKolkata: State Education minister Partha Chatterjee on Tuesday urged the Vice-Chancellor of Presidency University to take a humanitarian approach and complete the renovation of the Hindu hostel as fast as possible. Chatterjee on Tuesday spoke with V-C Anuradha Lohia and told her to take all possible measures to expedite the renovation work. The minister also enquired of the progress of work and the cause of delay in handing over the hostel.”The work for the Hindu Hostel has been going for a long time and the students have lost patience. So they are resorting to agitation which is affecting the prestige associated with the varsity. If the work could have been completed in time then there would not have been such an agitation,” Chatterjee said.Lohia on Monday had sought another four to five months from the students in handing over the hostel. She had claimed that the state Public Works Department (PWD) has not been able to complete the renovation work in time, causing the delay. The V-C had earlier promised to open the Hindu Hostel for students byJuly 15.last_img read more

From the coast of Italy

first_imgWould it not be nice to have an authentic slice of Italy in your mundane life in the Capital? Sorrento, the award-winning Italian restaurant at Shangri-La’s Eros Hotel, is offering its patrons an authentic Italian experience titled ‘Barefoot in the Sand’, a handcrafted menu of the signature dishes of Michelin Star Chef Riccardo Sculli. Having long been captivated and driven by the flavours of the pristine waters and the sandy beaches of the Ionian coast, the richly evocative menu enthrals for style, taste and the very quality of the raw materials itself. Also Read – Add new books to your shelfA special a-la-carte menu has been curated for lunch, featuring some of Chef Riccardo’s signature dishes such as – Carpaccio di Aragosta e verdure (Lobster carpaccio with seasonal salad and tomato gelè) and Risotto allo zafferano con mud granchio e ribes rosso (Saffron risotto, mud crab and red currants). For dinner, a special degustation menu has been designed by Chef Riccardo, starring culinary masterpieces such as Costoletta di agnello con carciofi e liquirizia (Rack of lamb with artichokes and liquorice) and Pollo ruspante con peperoni e arancia (Free-range chicken with peppers and orange). Also Read – Over 2 hours screen time daily will make your kids impulsiveKeeping in line with the traditions and rich culinary heritage of Calabria, some of Sorrento’s best wine selection have been paired with the stunning menu which is on till today.Chef Riccardo Sculli has especially flown down to curate this experience for the culinary enthusiasts of Delhi. He is the first chef from the Reggio Calabria province to have received a Michelin star, and is currently the head chef at Ristorante Gamberro Rosso, Marina di Gioiosa Jonica RC, Italy. Chef Riccardo is on a perpetual quest to keep educating himself about the extensive gastronomic legacy of Calabria, and to pay homage to this legacy through meticulously prepared and skillfully presented dishes.last_img read more

Mamata to leave for twoday tour of Birbhum today will hold administrative

first_imgKolkata: Chief Minister Mamata Banerjee will leave for a two-day tour of Birbhum on Wednesday. Banerjee will be chairing an administrative review meeting at Gitanjali Auditorium in Bolpur on Wednesday and on Thursday will be present at a distribution programme at VIP More in Kamarpara under Ilambazar police station area.A senior official in the district administration informed that the Chief Minister will also inaugurate the Baul & Lok Utsav from the venue at Ilambazar. “We have held meetings for the last few days and district magistrate Moumita Godara Basu along with senior officials paid a visit to the venue and gave necessary instructions. The top brass of police are also putting up a strong security blanket in and around the area,” the official said. Also Read – Rain batters Kolkata, cripples normal lifeThree helipads have been set up in the area, with one at the backside of Gitanjali Auditorium, another at Binoy Bhavan Stadium in the campus of Visva Bharati and the third one at Kamarpura adjacent to the stadium in which the Chief Minister’s distribution programme has been scheduled. Banerjee will lay the foundation stones of various projects and inaugurate a number of schemes at her distribution programme on Thursday. She will also award prizes to winners of various sports events and Jangalmahal Cup. Men and women in the districts who have excelled in sports activities will be also handed over prizes by the Chief Minister. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedThe district police have already held a rehearsal on how the beneficiaries will go to the stage and collect awards from Banerjee. A large number of farmers will also be handed over toolkits at the venue. A major attraction of the programme will be 1,000 Bauls with their ektaras and other similar musical instruments. Around 100 Bauls will perform on the main stage. The administrative review meeting will be attended by senior officials of the Block, Zilla Parishad and Panchayat level, senior police officials and officers-in-charge of all police stations in the district.last_img read more

Water sports may expose you to antibioticresistant bacteria

first_imgLove to play water sports like surfing or bodyboarding? Beware, you may be three times more likely to swallow antibiotic-resistant Escherichia coli or E.coli bacteria in your guts, new research has revealed. Surfers were found to swallow ten times more sea water than sea swimmers, making them more vulnerable to E.coli bacteria.Regular surfers were also found four times as likely to harbour bacteria that contain mobile genes that make bacteria resistant to the antibiotic. Also Read – Add new books to your shelfThis is significant because the genes can be passed between bacteria – potentially spreading the ability to resist antibiotic treatment between bacteria, the researchers said. “Antimicrobial resistance has been globally recognised as one of the greatest health challenges of our time, and there is now an increasing focus on how resistance can be spread through our natural environments,” said Anne Leonard, from the University of Exeter. Scientists compared faecal samples from 300 surfers and non-surfers to assess whether the surfers’ guts contained E.coli bacteria that were able to grow in the presence of cefotaxime. Also Read – Over 2 hours screen time daily will make your kids impulsiveThe study, published in the journal Environment International, found that 13 of 143 (9 per cent) of surfers were colonised by these resistant bacteria, compared to just four of 130 (3 per cent) of non-surfers swabbed.A treatment with cefotaxime – a commonly used and clinically important antibiotic previously prescribed to kill off E.coli bacteria – showed that the bacteria has acquired genes that enable them to survive this treatment, the study showed.According to the 2016 O’Neill report commissioned by the UK government, antimicrobial resistant infections could kill one person every three seconds by the year 2050 if current trends continue.There is an urgent need to curb antibiotic-resistance or else we may be entering an era in which antibiotics are no longer effective to kill simple, and previously treatable, bacterial infections, warned the World Health Organization.last_img read more