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Visualizzazione dei post in ordine di pertinenza per la query signal. Ordina per data Mostra tutti i post
Visualizzazione dei post in ordine di pertinenza per la query signal. Ordina per data Mostra tutti i post

sabato 25 luglio 2020

# gst: a simple signal to drive complex dynamics

<< a developmental signaling pattern can be erased and replaced with a synthetic, patterned stimulus. (..) unlike pharmacological or genetic perturbations, light can be applied and removed quickly, focused with high spatial precision, or shaped into arbitrary spatial patterns. (AA) found that a simple all-or-none blue light stimulus, delivered to the embryonic termini, is sufficient to convert a lethal loss-of-function phenotype to rescue the full Drosophila life cycle: embryogenesis; larval development; pupation; adulthood; and fecundity. >>

<<  Such optical control over development could be used to probe cell and tissue-level regulation, engineer tissue organization, and correct developmental defects. >>

Heath E. Johnson, Nareg J.V. Djabrayan, et al. Optogenetic Rescue of a Patterning Mutant. Current Biology. 30, 1-11. doi: 10.1016/ j.cub.2020.06.059. Jul 23, 2020. 


Complex developmental patterns are under the control of surprisingly simple signals. Princeton University. Jul 23, 2020.


Also

keyword 'signal' in FonT


keyword 'signal' in Notes (quasi-stochastic poetry)





martedì 27 marzo 2018

# brain: strong signals to connect to consciousness

<< Unexpectedly, our model reveals that only when the signal is strong enough, above a threshold level, the signal reaches a large set of areas of the brain region called the prefrontal cortex, which plays a critical role in high-level cognition >> Madhura Joglekar.

James Devitt. From Signal Propagation to Consciousness: A Potential Connection Discovered. Neuroscience News. Mar 22, 2018.

http://neurosciencenews.com/consciousness-signal-propagation-8674/amp/  

Madhura R. Joglekar, Jorge F. Mejias, et al. Inter-areal Balanced Amplification Enhances Signal Propagation in a Large-Scale Circuit Model of the Primate Cortex. Neuron.
doi: 10.1016/j.neuron.2018.02.031.
Mar 22, 2018.

http://www.cell.com/neuron/fulltext/S0896-6273(18)30152-1

lunedì 26 agosto 2019

# gst: the hypothesis to optimize multiplicative noise to enhance a signal-to-noise ratio

AA << study simple integrate-and-fire type models with multiplicative noise and consider the transmission of a weak and slow signal, >>

<< The specific question of interest is whether and how the state-dependence of the noise can be optimized with respect to information transmission >>

<< also in a biophysically more relevant situation, multiplicative noise can enhance the signal-to-noise ratio (..) results shed light on a so far unexplored aspect of stochastic signal transmission in neural systems. >>

Jonathan Bauermann Benjamin Lindner. Multiplicative noise is beneficial for the transmission of sensory signals in simple neuron models. Biosystems. Volume 178, Apr 2019, Pages 25-31. doi: 10.1016/ j.biosystems.2019.02.002

https://www.sciencedirect.com/science/article/pii/S0303264718303861

mercoledì 30 giugno 2021

# gst: weird Nature; randomly arranged nanowire networks seem to behave, at the edge of chaos, like cortical neuronal cultures

<< an artificial network of nanowires can be tuned to respond in a brain-like way when electrically stimulated. >>️

<< If the signal stimulating the network was too low, then the pathways were too predictable and orderly and did not produce complex enough outputs to be useful. If the electrical signal overwhelmed the network, the output was completely chaotic and useless for problem solving. The optimal signal for producing a useful output was at the edge of this chaotic state. >>️

<< Some theories in neuroscience suggest the human mind could operate at this edge of chaos, or what is called the critical state, (..) Some neuroscientists think it is in this state where we achieve maximal brain performance. (..) What's so exciting about this result is that it suggests that these types of nanowire networks can be tuned into regimes with diverse, brain-like collective dynamics, which can be leveraged to optimize information processing. >> Zdenka Kuncic.️

<< In the nanowire network the junctions between the wires allow the system to incorporate memory and operations into a single system. This is unlike standard computers, which separate memory (RAM) and operations (CPUs). >>

<< These junctions act like computer transistors but with the additional property of remembering that signals have traveled that pathway before. As such, they are called 'memristors', >> Joel Hochstetter.
'Edge of chaos' opens pathway to artificial intelligence discoveries. University of Sydney. Jun 29, 2021.


Joel Hochstetter, Ruomin Zhu, et al. Avalanches and edge-of-chaos learning in neuromorphic nanowire networks. Nat Commun 12, 4008. doi: 10.1038/ s41467-021-24260-z. Jun 29, 2021.





mercoledì 9 settembre 2020

# gst: to reach detectability of a weak signal, they add background noise

<< In contrast to most sensors, for which noise is a problem that should be suppressed, (AA) found that adding just the right amount of background noise can actually increase a signal too weak for sensing by normal sensors, to a level that can reach detectability. >>

Walt Mills. To make a better sensor, just add noise. Pennsylvania State University. Sep 03, 2020. 


<< In this article, (AA) adopt a radical approach for next generation ultra-low-power sensor design by embracing the evolutionary success of animals with extraordinary sensory information processing capabilities that allow them to survive in extreme and resource constrained environments. Stochastic resonance (SR) is one of those astounding phenomena, where noise, which is considered detrimental for electronic circuits and communication systems, plays a constructive role in the detection of weak signals. >>

Akhil Dodda, Aaryan Oberoi, et al. 
Stochastic resonance in MoS2 photodetector. Nat Commun 11, 4406 (2020). doi: 10.1038/ s41467-020-18195-0. Sep 2, 2020.


Also 

keyword 'noise' in FonT


Also 

plus ambiguity and noise. Notes. Jul 06, 2007  (quasi-stochastic poetry)




martedì 19 aprile 2016

# s-psych: in the first moments ... to establish a rank asymmetry

<< You  may  not  win  friends,  but  a  new  study  finds  that  you  can  influence people  simply  by  lowering  the  pitch  of  your  voice  in  the  first  moments  of  a  conversation. >>

<< (..)  people whose  voices  went  down  in  pitch  early  on  in  an  interaction  were  more  likely  to  be  seen  as dominant  and  influential  than  those  whose  vocal  pitch  went  up  early  in  conversation. Those  viewed  as  dominant  also  were  more  likely  to  convince  others  to  go  along  with  their ideas  than  those  seen  as  less  dominant. >>

<< “What  excites  me  about  this  research  is  that  we  now  know  a  little  bit  more  about  how humans  use  their  voices  to  signal  status,”  said (..) Joey  Cheng >>

Diana Yates. Psychology  professor  Joey  Cheng  and  her  colleagues  found  that  changes  in  vocal  pitch coincided  with  dominancebut  not  prestige,  in  small  groups  working  together  on  a  task. Apr 18, 2016 9:30 AM

https://news.illinois.edu/blog/view/6367/352099

<< Similar  to  the  nonverbal  signals  shown  by  many  non human  animals  during  aggressive conflictshumans  display  a  broad  range  of  behavioral  signals  to  advertise  and  augment their  apparent  sizestrength,  and  fighting  prowess  when  competing  for  social dominanceFavored  by  natural  selectionthese  signals  communicate  the  displayer’s capacity  and  willingness  to  inflict  harm,  and  increase  responders’  likelihood  of  detecting and  establishing  a  rank  asymmetry,  and  thus  avoiding  costly  physical  conflicts. >>

<< Together [ from Study 1 and Study 2]findings suggest  that  humans  use  transient  vocal  changes  to  tracksignal,  and  coordinate status  relationships. >>

Cheng, Joey  T.,  Tracy, Jessica  L., et al. Listenfollow  me:  Dynamic  vocal  signals  of dominance  predict  emergent  social  rank  in  humans. Journal  of  Experimental  Psychology:  General,  Vol  145(5),  May  2016, 536-547.

http://dx.doi.org/10.1037/xge0000166

lunedì 2 gennaio 2017

# s-astro: exploring the sea of ‘noise’ to understand intricacies

<< Rather than trying to filter out the signal “noise” from stars around which exoplanets are orbiting, (AA) studied all of the signal information together to understand the intricacies within its structure >>

Jim Shelton. Searching a sea of ‘noise’ to find exoplanets — using only data as a guide.  Dec. 20, 2016

http://news.yale.edu/2016/12/20/searching-sea-noise-find-exoplanets-using-only-data-guide

Sahil Agarwal, Fabio Del Sordo and John S. Wettlaufer. Exoplanetary Detection by  multifractal spectral analysis. Publ. 2016  Dec.  20, 2016. The  Astronomical  Journal, Volume  153, Number  1;  doi 10.3847/1538-3881/153/1/12

http://iopscience.iop.org/article/10.3847/1538-3881/153/1/12

mercoledì 16 ottobre 2019

# gst: counterintuitively, even complex processes can be hidden inside flat power spectra

<< Power spectral densities are a common, convenient, and powerful way to analyze signals. So much so that they are now broadly deployed across the sciences and engineering - from quantum physics to cosmology, and from crystallography to neuroscience to speech recognition. The features they reveal not only identify prominent signal-frequencies but also hint at mechanisms that generate correlation and lead to resonance. Despite their near-centuries-long run of successes in signal analysis, here (AA) show that flat power spectra can be generated by highly complex processes, effectively hiding all inherent structure in complex signals.  >>

P. M. Riechers, J. P. Crutchfield.  Fraudulent White Noise: Flat power spectra belie arbitrarily complex processes.   arXiv:1908.11405v1 [cond-mat.stat-mech] Aug 29, 2019.   https://arxiv.org/abs/1908.11405

lunedì 7 agosto 2017

# s-evol: a noise effect inside: new species pulsating by chance instead of ...

<< W. Andrew Barr, a visiting assistant professor of anthropology, published a report that says it's possible the pulse of new species could have occurred by chance and might not be directly related to climate change >>

Researcher's paper challenges the claim that the genus Homo originated in response to environmental changes. Aug 4, 2017

https://m.phys.org/news/2017-08-paper-genus-homo-response-environmental.html

W. Andrew Barr. Signal or noise? A null model method for evaluating the significance of turnover pulses. Paleobiology 2017 doi: 10.1017/pab.2017.21 Publ. online: 31 July 2017

https://www.cambridge.org/core/journals/paleobiology/article/signal-or-noise-a-null-model-method-for-evaluating-the-significance-of-turnover-pulses/17FBC5F2A96CA2BA0657A2E411170EAB#

also

<< "Nell' Arte tutto e', o dovrebbe essere, un esperimento". Gill Evans. >>

2127 - enigmistiche tonalita'. March 23, 2007

http://inkpi.blogspot.it/2007/03/2127-enigmistiche-tonalita.html

sabato 5 giugno 2021

#life: reliability, deception and lies of a signal (among the Siberian jay Perisoreus infaustus)

<< Deception and lies are surprising aspects of human communication and the use of language in which false information is intentionally communicated to others, allowing an individual to gain an advantage over the recipient of such false information. However, language is actually highly pro-social and cooperative and is mainly used to share reliable information. >>️

<< a number of species are able to deceive their conspecifics, including some species of primates and birds like the Siberian jay (Perisoreus infaustus). Siberian jays live in territorial groups and have an elaborate communication system: A wide range of calls allow them to warn each other of the presence of different predators as well as the behaviour of their fiercest enemy, the hawk. >>

<< Occasionally, however, neighbours intruding into a group's territory use the same calls that would otherwise indicate the presence of a perched hawk for a different purpose. Their aim is to deceive the members of the group about the presence of the predator, thus scaring them away to get access to their food.  >>

<< It is a commonly observed phenomenon in the animal kingdom that warning calls are used to deceive others. Clearly, the recipients of the false information potentially pay a high price if they ignore the warning, >>  Filipe Cunha. 

<< Siberian jays thus have a simple rule to avoid being tricked: They only trust the warning calls from members of their own group, meaning cooperation partners. Familiarity alone is not enough, otherwise the birds would also have trusted the calls of their neighbours, >> Michael Griesser. ️

Daniel Schmidtke. Trust among corvids. University of Konstanz. Jun 1, 2021. 


Filipe C. R. Cunha, Michael Griesser. Who do you trust? Wild birds use social knowledge to avoid being deceived. Science Advances. Vol. 7, no. 22, eaba2862. doi: 10.1126/ sciadv.aba2862. May 28, 2021. 


Also

2068 - chaotic probabilities. 
(quasi-stochastic poetry)


keyword "fake" in FonT



lunedì 18 giugno 2018

# geo: low frequency sounds that resemble the shape of the tornillo seismic waves

AA << characterize and interpret a new type of infrasound signal originating from the summit of Volcán Cotopaxi (Ecuador) >>

<< This infrasound waveform is a slowly decaying sinusoid with exceptional low‐frequency (..) and high quality factor (..) and resembles the shape of tornillo seismic waveforms. >>

Johnson JB,  Ruiz MC, et al. Infrasound Tornillos Produced by Volcán Cotopaxi's Deep Crater. Geophysical Research Letters. doi: 10.1029/2018GL077766. Jun 13,  2018.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL077766

Volcano music could help scientists monitor eruptions. American Geophysical Union. Jun 15, 2018.

https://m.phys.org/news/2018-06-volcano-music-scientists-eruptions.html

domenica 15 maggio 2016

# s-gene: extensive, quantitative perturbation approach to trace "the poetry" of gene regulatory networks

<<  DNA  content  of  our  genomes  resembles  a  complex  biological  languagecomposed  of  coding  regions and  regulatory  regionsAlthough  protein-coding  regions  in  DNA  could  be  compared  to  a  traffic  signal  –  utilizing  a  simple  stop  or  go  message  –  the regulatory  regions  in  DNA  are  more  like  poetry. “The  regulatory  sites  in  DNA  operate  like  a  light  switch  to  turn  a  gene  on  and  off.  In  animalsit’s  extremely  complex,”  said  David  Arnosti (..) “There  might  be  hundreds  of  protein  factors  in  the  cell  that  bind  to  the gene  and  impact  activity.  And  there  might  be  hundreds  of  binding  places.” He  compares  the  “language”  used  in  these  regulatory  sites  to  poetry. “It  may  be  Emily  Dickinson,  or  Shakespeare  or  Allen  Ginsberg;  but  all  are  using  ‘words’  to  evoke  thoughts  and  emotionsto  control  the  message” >>

Val  Osowski, Layne  Cameron. DO GENES EXPRESS THEMSELVES THROUGH POETRY? A  new study  from  Michigan  State  University  makes  inroads  in  learning  to  “read”  the  genome,  a  key  goal  of  modern  biology. Published:  May  9,  2016

http://msutoday.msu.edu/news/2016/do-genes-express-themselves-through-poetry/

To  understand  transcription  factor  interactions  on  enhancers  << (..) an  extensive,  quantitative  perturbation  analysis targeting  the  dorsal-ventral  patterning  gene  regulatory  network  (GRNcontrolled  by  Drosophila NF-κB  homolog  Dorsal [was used to test] the effects  of  cooperativityrepression,  and factor  potency >>

Rupinder  Sayal,  Jacqueline  M  Dresch, et al. Quantitative  perturbation-based  analysis  of  gene expression  predicts  enhancer  activity  in  early Drosophila  embryo. eLife  2016;5:e08445. Published  May  6,  2016

http://dx.doi.org/10.7554/eLife.08445

mercoledì 3 giugno 2020

# behav: persistent neuronal firing during flight in flies, like a pulsating gambler who has to decide quickly

<< A general principle of sensory systems is that they adapt to prolonged stimulation by reducing their response over time. >>

<< as opposed to most sensory and visual neurons, and in particular to the motion vision sensitive neurons in the brains of both flies and mammals, the descending neurons show little adaption during stimulus motion. (..) the optic-flow-sensitive descending neurons display persistent firing, or an after-effect, following the cessation of visual stimulation, consistent with the lingering calcium signal hypothesis. >>

AA results << show a combination of adaptation and persistent firing in the neurons that project to the thoracic ganglia and thereby control behavioral output. >>

Sarah Nicholas, Karin Nordstrom. Persistent Firing and Adaptation in Optic-Flow-Sensitive Descending Neurons. Curr Biol. doi: 10.1016/ j.cub.2020.05.019. May 28, 2020.


Revealing how flies make decisions on the fly to survive. Flinders University. May 28, 2020


Also

the flexible mental maps of flies. FonT. Nov 21, 2019. 


<< Considerando invece l' immagine classica della "mosca nella bottiglia", >>  in: 2066 - voli a casaccio. Notes. (quasi-stochastic poetry). Oct 01, 2006.



mercoledì 13 luglio 2016

# s-nanotech: displayed by an electronic tattoo

<< A new temporary "electronic tattoo" (..)  that can measure the activity of muscle and nerve cells (..) is poised to revolutionize medicine, rehabilitation, and even business and marketing research. >>

<< The tattoo consists of a carbon electrode, an adhesive surface that attaches to the skin, and a nanotechnology-based conductive polymer coating that enhances the electrode's performance. It records a strong, steady signal for hours on end without irritating the skin. >>

<< The electrode (..)  may improve the therapeutic restorationof damaged nerves and tissue -- and may even lead to new insights into our emotional life. >>

Nanotechnology 'tattoo' can map emotionsand monitor muscle activity. Jul 11, 2016.

http://www.nanowerk.com/nanotechnology-news/newsid=43905.php

domenica 24 dicembre 2017

# behav: a form of modified oxytocin (a molecule of love), with less adverse effects

<< Oxytocin is clinically used to induce labor, and there is interest in using this peptide to treat social disorders. However, oxytocin triggers adverse cardiovascular side effects  >>

AA << generated ligands based on oxytocin with subtle modifications >>

this new molecular form << reduced social fear in mice and induced contractile activity in human myometrial strips without affecting cultured cardiomyocytes >>

Markus Muttenthaler, Asa Andersson, et al.  Subtle modifications to oxytocin produce ligands that retain potency and improved selectivity across species. Sci. Signal.  2017; 10 (508): eaan3398. 10.1126/scisignal.aan3398. Dec 05, 2017.

http://stke.sciencemag.org/content/10/508/eaan3398

Scientists create molecule of love with less complications. Dec 12, 2017.

https://m.phys.org/news/2017-12-scientists-molecule-complications.html

lunedì 15 marzo 2021

# gst: an atomic imaging of a (slow) crack

AA << successfully imaged the snapping of individual atomic bonds in a one-atom-thick sheet of rhenium disulfide ( ReS2) using scanning transmission electron microscopy. (STEM) >>

<< Because of its unusual chemistry, Re forms a 2D lattice with "lanes" that guide cracks, allowing the cracks to propagate with ease. The heavy element also efficiently deflects electrons, providing the signal needed to gain clear images. The study is a remarkable example of how a specific material can provide insight into the universal behavior of matter. >>

<< Because of its strong scattering, ReS2 provides an ideal target for STEM. (Interestingly, tungsten, the periodic-table neighbor of Re, has just one fewer proton and is routinely used in electron microscopy to stain viruses and bacterial flagella.)  >>

<< By measuring the deformation of the lattice around the crack, the team showed that the tearing stresses were concentrated around the crack tip. The stresses then decayed as the inverse square root of the distance from the tip, a finding that matches predictions for macroscopic materials. Using these measurements, the team defined a stress intensity threshold for cracks to propagate. >>

<< The images taken by Huang and colleagues used seconds-long exposure times, meaning they could only follow the propagation of the slowest crack (those that moved at a few angstroms per second). There is much interest in how faster cracks behave, as these cracks are subject to instabilities, meaning they can deviate from a straight line or form branches, for example. To observe faster cracks, future experiments could use reduced exposure times. >>

Itamar Kolvin. Atomic Imaging of Cracks. Physics 13, 193. Dec 9, 2020. 


Lingli Huang, Fangyuan Zheng, et al. In Situ Scanning Transmission Electron Microscopy Observations of Fracture at the Atomic Scale. Phys. Rev. Lett. 125, 246102. Dec 9, 2020.


Also

(+)  the intriguing dynamics of a crack. Nov 7, 2017. 


(+) multiple cracks, simultaneously ... Oct 23, 2016.


(+) onda criptica. May 22, 2005 (quasi-stochastic poetry)


(+) keyword "fracture" in FonT







giovedì 24 dicembre 2015

# s-trade-behav: "harbinger of failure" (human) scanners

<< (..) customers, termed “Harbingers of failure,” who systematically purchase new products that flop. Their early adoption of a new product is a strong signal that a product will fail—the more they buy, the less likely the product will succeed >>

Eric Anderson, Song Lin, et al. Harbingers of Failure. Journal of Marketing Research, 2015; 52 (5): 580 DOI: 10.1509/jmr.13.0415

http://journals.ama.org/doi/10.1509/jmr.13.0415

http://news.mit.edu/2015/harbinger-failure-consumers-unpopular-products-1223

mercoledì 18 maggio 2022

# brain: jazzy perceptions inside, there’s more to all the noise; even in the dark, neurons of the visual cortex chat

<< Scientists are now rethinking how they study and conceive of perception. >>

<< At every moment, neurons whisper, shout, sputter and sing, filling the brain with a dizzying cacophony of voices. Yet many of those voices don’t seem to be saying anything meaningful at all. They register as habitual echoes of noise, not signal; as static, not discourse. >>️

<< But over the past decade, that view has changed. (..) There’s more to all the noise, scientists realized, than they had assumed. >>️

<< Now, by analyzing both the neural activity and the behavior of mice in unprecedented detail, researchers have revealed a surprising explanation for much of that variability: Throughout the brain, even in low-level sensory areas like the visual cortex, neurons encode information about far more than their immediately relevant task. They also babble about whatever other behaviors the animal happens to be engaging in, even trivial ones — the twitch of a whisker, the flick of a hind leg. Those simple gestures aren’t just present in the neural activity. They dominate it. >>️

<< Our brains aren’t just thinking in our heads. Our brains are interacting with our bodies and the way that we move through the world. >> Cris Niell. 

<< Wait — maybe the brain isn’t noisy. Maybe it’s actually much more precise than we thought, >> David McCormick️.️

Jordana Cepelewicz. ‘Noise’ in the Brain Encodes Surprisingly Important Signals. Quantamag. Nov 7, 2019. 


Salkoff DB, Zagha E, McCarthy E, McCormick DA. Movement and Performance Explain Widespread Cortical Activity in a Visual Detection Task. Cereb Cortex. 2020 Jan 10;30(1):421-437. doi: 10.1093/ cercor/bhz206. 


Also

keyword 'perception' in FonT


keyword 'percezione' | 'percezioni' in Notes (quasi-stochastic poetry)



keyword 'error' | 'fuzzy' | 'noise'  in FonT 




keywords 'errore' | 'errori' in Notes (quasi-stochastic poetry)



keyword 'jazz' in FonT


keyword 'jazz' in Notes (quasi-stochastic poetry):


Keywords: brain, perception, visual cortex, noise









sabato 5 ottobre 2019

# evol: echolocation, a prime example of convergent evolution

<< Echolocation is a prime example of convergent evolution, the independent gain of similar features in species of different lineages. >>

<< Distantly related species entering similar biological niches often adapt by evolving similar morphological and physiological characters. How much genomic molecular convergence (particularly of highly constrained coding sequence) contributes to convergent phenotypic evolution, such as echolocation in bats and whales, is a long-standing fundamental question.  >>

AA << find that the gene set most overrepresented (q-value = 2.2e-3) with convergent substitutions in echolocators, affecting 18 genes, regulates development of the cochlear ganglion, a structure with empirically supported relevance to echolocation. >>

Amir Marcovitz, Yatish Turakhia, et al. A functional enrichment test for molecular convergent evolution finds a clear protein-coding signal in echolocating bats and whales.
PNAS doi: 10.1073/pnas.1818532116   Sep 30, 2019    https://www.pnas.org/content/early/2019/09/27/1818532116 

Krista Conger. Scientists uncover genetic similarities among species that use sound to navigate. Stanford University Medical Center. Oct 4, 2019.   https://m.phys.org/news/2019-10-scientists-uncover-genetic-similarities-species.html

venerdì 17 maggio 2019

# sec: adversarial audio attacks; small sound perturbations to hack a Machine Learning model and remedies

<< Adversarial audio attacks can be considered as a small perturbation unperceptive to human ears that is intentionally added to the audio signal and causes a machine learning model to make mistakes. >>

Mohammad Esmaeilpour, Patrick Cardinal, Alessandro Lameiras Koerich. A Robust Approach for Securing Audio Classification Against Adversarial Attacks. arXiv:1904.10990 [cs.LG] Apr 24, 2019.

https://arxiv.org/abs/1904.10990

Ingrid Fadelli. An approach for securing audio classification against adversarial attacks. May 7, 2019.

https://m.techxplore.com/news/2019-05-approach-audio-classification-adversarial.html