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Luís F. Simões

Evolution of AI Interplanetary Trajectories Reaches Human-Competitive Levels - Slashdot - 4 views

science.slashdot.org/...aches-human-competitive-levels

AI MAD GTOC PaGMO evolutionary computation trajectory optimization awards

shared by Luís F. Simões on 19 Jul 13 - No Cached
  • "It's not the Turing test just yet, but in one more domain, AI is becoming increasingly competitive with humans. This time around, it's in interplanetary trajectory optimization. From the European Space Agency comes the news that researchers from its Advanced Concepts Team have recently won the Gold 'Humies' award for their use of Evolutionary Algorithms to design a spacecraft's trajectory for exploring the Galilean moons of Jupiter (Io, Europa, Ganymede and Callisto). The problem addressed in the awarded article (PDF) was put forward by NASA/JPL in the latest edition of the Global Trajectory Optimization Competition. The team from ESA was able to automatically evolve a solution that outperforms all the entries submitted to the competition by human experts from across the world. Interestingly, as noted in the presentation to the award's jury (PDF), the team conducted their work on top of open-source tools (PaGMO / PyGMO and PyKEP)."
  • Luís F. Simões on 19 Jul 13
     
    We made it to Slashdot's frontpage !!! :)
  • Ma Ru on 23 Jul 13
     
    Congratulations, gentlemen!
johannessimon81

High efficiency solid state heat engine - 0 views

www.parc.com/...ciency-solid-state-engine.html

nrg technology

shared by johannessimon81 on 22 Aug 13 - No Cached
  • johannessimon81 on 22 Aug 13
     
    We discussed this today during coffee. The inventor claims that he claims that a pressure differential can push hydrogen through a proton conductive membrane (thereby stripping off the electrons) which flow through an electric circuit and provide electric power. The type of membrane is fairly similar to that found in a hydrogen fuel cell. If the pressure differential is cause by selective heating this is in essence a heat engine that directly produces electricity. The inventor claims that this could be a high efficiency alternative to thermoelectric devices and could even outperform PV and Sterling engines with an efficiency close to that of fuel cells (e.g., ~60% @ dT=600K). I could not find any scientific publications as the inventor is not affiliated to any University - he has however an impressive number of patents from a very wide field (e.g., the "Super Soaker" squirt gun) and has worked on several NASA and US military projects. His current research seams to be funded by the latter as well. Here are some more links that I found: http://www.theatlantic.com/magazine/archive/2010/11/shooting-for-the-sun/308268/ http://www.johnsonems.com/?q=node/13 http://scholar.google.nl/scholar?q=%22lonnie+g+johnson%22+&btnG=&hl=nl&as_sdt=0%2C5
Thijs Versloot

Existence of new element confirmed - 1 views

www.lunduniversity.lu.se/o.o.i.s

science

shared by Thijs Versloot on 28 Aug 13 - No Cached
  • Thijs Versloot on 28 Aug 13
     
    An international team of researchers, led by physicists from Lund University, have confirmed the existence of what is considered a new element with atomic number 115. The experiment was conducted at the GSI research facility in Germany. The results confirm earlier measurements performed by research groups in Russia.
jcunha

Maze-solving automatons can repair broken circuits - 1 views

scitation.aip.org/...1.4916513

technology PHY space

shared by jcunha on 09 Apr 15 - No Cached
  • jcunha on 09 Apr 15
     
    Researchers in Bangalore, India together with the Indian Space Research organization come up with an intelligent self-healing algorithm that can locate open-circuits faults and repair them in real-time. They used an insulating silicon oil containing conductive particles. Whenever a fault happens, an electric field develops there, causing the fluid to move in a 'thermodynamic automaton' way repairing the fault. The researchers make clear it could be one advantage for electronics in harsh environments, such as in space satellites.
Thijs Versloot

Time 'Emerges' from #Quantum Entanglement #arXiv - 1 views

medium.com/...d5d3dc850933

science quantum relativity

shared by Thijs Versloot on 23 Oct 13 - No Cached
  • Thijs Versloot on 23 Oct 13
     
    Time is an emergent phenomenon that is a side effect of quantum entanglement, say physicists. And they have the first exprimental results to prove it
  • ...5 more comments...
  • johannessimon81 on 23 Oct 13
     
    I always feel like people make too big a deal out of entanglement. In my opinion it is just a combination of a conserved quantity and an initial lack of knowledge. Imagine that I had a machine that always creates one blue and one red ping-pong ball at the same time (|b > and |r > respectively). The machine now puts both balls into identical packages (so I cannot observe them) and one of the packages is sent to Tokio. I did not know which ball was sent to Tokio and which stayed with me - they are in a superposition (|br >+|rb >), meaning that either the blue ball is with me and the red one in Tokio or vice versa - they are entangled. So far no magic has happened. Now I call my friend in Tokio who got the ball: "What color was the ball you received in that package?" He replies: "The ball that I got was blue. Why did you send me ball in the first place?" Now, the fact that he told me makes the superpositon wavefunction collapse (yes, that is what the Copenhagen interpretation would tell us). As a result I know without opening my box that it contains a red ball. But this is really because there is an underlying conservation law and because now I know the other state. I don't see how just looking at the conserved quantity I am in a timeless state outside of the 'universe' - this is just one way of interpreting it. By the way, the wave function for my box with the undetermined ball does not collapse when the other ball is observed by my friend in Tokio. Only when he tells me does the wavefunction collapse - he did not even know that I had a complementary ball. On the other hand if he knew about the way the experiment was conducted then he would have known that I had to have a red ball - the wavefunction collapses as soon as he observed his ball. For him it is determined that my ball must be red. For me however the superposition is intact until he tells me. ;-)
  • Luzi Bergamin on 24 Oct 13
     
    Sorry, Johannes, you just develop a simple hidden-parameters theory and it's experimentally proven that these don't work. Entangeled states are neither the blue nor the red ball they are really bluered (or redblue) till the point the measurement is done.
  • Luzi Bergamin on 24 Oct 13
     
    Hm, to me this looks like a bad joke... The "emergent time" concept used is still the old proposal by Page and Whotters where time emerges from something fundamentally unobservable (the wave function of the Universe). That's as good as claiming that time emerges from God. If I understand correctly, the paper now deals with the situation where a finite system is taken as "Mini-Universe" and the experimentalist in the lab can play "God of the Mini-Universe". This works, of course, but it doesn't really tell us anything about emergent time, does it?
  • johannessimon81 on 24 Oct 13
     
    Actually, it has not been proven conclusively that hidden variable theories don' work - although this is the opinion of most physicists these days. But a non-local hidden variable would still be allowed - I don't see why that could not be equivalent to a conserved quantity within the system. As far as the two balls go it is fine to say they are undetermined instead of saying they are in bluered or redblue state - for all intents and purposes it does not affect us (because if it would the wavefunction would have collapsed) so we can't say anything about it in the first place.
  • Luzi Bergamin on 24 Oct 13
     
    Non-local hidden variables may work, but in my opinion they don't add anything to the picture. The (at least to non-physicists) contraintuitive fact that there cannot be a variable that determines ab initio the color of the ball going to Tokio will remain (in your example this may not even be true since the example is too simple...).
  • johannessimon81 on 24 Oct 13
     
    I guess I tentatively agree with you on both points. In the end there might anyway be surprisingly little overlap between the way that we describe what nature does and HOW it does it... :-D
  • Luzi Bergamin on 24 Oct 13
     
    Congratulations! 100% agree.
jcunha

Interference of thermal waves - Can heat be controlled as waves? - 1 views

phys.org/...can-heat-be-controlled-as.html

technology PHY solid state thermal management science

shared by jcunha on 26 Jun 15 - No Cached
  • jcunha on 26 Jun 15
     
    Imagine a material that only admits thermal conduction for certain temperatures. Martin Maldovan from Georgia Tech holds a tiny thermoelectric device that turns cold on one side when current is applied. Recent research has focused on the possibility of using interference effects in phonon waves to control heat transport in materials. These are exciting news (see Nature Materials paper here http://www.nature.com/nmat/journal/v14/n7/full/nmat4308.html). Heterostructure research lead to outstanding new possibilities when applied to electronic transport (e.g. in quantum well and quantum dots) and to photonics (e.g. Quantum Cascade Laser tunnable lasers). Apparently the time has come to see selective thermal control in this way! Truly exciting!!
pacome delva

A Battery Made With Paper - 0 views

sciencenow.sciencemag.org/...2

phy nrg nan carbon_nanotubes batteries

shared by pacome delva on 09 Dec 09 - Cached
LeopoldS liked it
  • Researchers are reporting that they've made batteries and other energy-storage devices by printing layers of carbon nanotube–based ink atop standard photocopy paper. The result is a highly conductive sheet that can carry a charge and be easily incorporated into a flexible battery. Because of paper's low cost, that could help lower the price of batteries used in electric vehicles, wind farms, and other renewable sources.
  • LeopoldS on 13 Dec 09
     
    can we use it for space :-) ?
pacome delva

101 uses for guar gum - 0 views

www.rsc.org/...guar_gum.asp

phy soft_matter gel_film

shared by pacome delva on 01 Sep 09 - Cached
  • Guar gum, a polysaccharide, is a cheap and environmentally friendly material produced naturally by a leguminous shrub.
  • The film has a high tensile strength and Kadokawa says it can conduct electricity as efficiently as semi-conductors.   Uniquely, the film hardens upon heating but becomes soft again as it cools. These properties mean that it could be used to produce temperature sensors.
pacome delva

Molecular Currents - 0 views

focus.aps.org/st17

phy electronics molecules

shared by pacome delva on 09 Nov 09 - Cached
  • European researchers have measured the electrical conductance between a single pair of precisely oriented C60 molecules.
  • For the ultimate in miniaturization, researchers want to learn all they can about using molecules in electronic circuits. They have measured currents between molecules but not with a precise understanding of the configuration and positions of the molecular electrons.
Luís F. Simões

Pioneer Anomaly Solved By 1970s Computer Graphics Technique - Technology Review - 4 views

www.technologyreview.com/...26589

pioneer anomaly PHY astrophysics

shared by Luís F. Simões on 31 Mar 11 - No Cached
Nicholas Lan liked it
  • Now Frederico Francisco at the Instituto de Plasmas e Fusao Nuclear in Lisbon Portugal, and a few pals, say they've worked out where the thermal calculations went wrong. These guys have redone the calculations using a computer model of not only how the heat is emitted but how it is reflected off the various parts of the spacecraft too. The reflections turn out to be crucial.
  • Ref: arxiv.org/abs/1103.5222: Modelling The Reflective Thermal Contribution To The Acceleration Of The Pioneer Spacecraft
  • santecarloni on 01 Apr 11
     
    This is really cool. I know one of the authors and he is a good guy... the only thing that leaves me unsatisfied is that if the whole issue is related to thermal effects one should have seen the Pioneer effect all the time and not only at about 10 AU... ...or is there some thermal process that kicked in only at this distance?
  • Luís F. Simões on 26 Jul 11
     
    Here's an update on this theory: NASA Releases New Pioneer Anomaly Analysis "The mysterious force acting on the Pioneer spacecraft seems to be falling exponentially. That's a strong clue that on-board heat is to blame, says NASA." Heat emission 'most likely cause' of pioneer anomaly "What's more interesting is that, contrary to the original analysis conducted all those years ago, the deceleration does seem to be decelerating at an exponential rate -- just as one might expect from the radioactive decay of plutonium-238, which powers the two spacecraft. Turyshev concludes, "The most likely cause of the Pioneer anomaly is the anisotropic emission of on-board heat.""
santecarloni

[1107.0392] Emergence of good conduct, scaling and Zipf laws in human behavioral sequen... - 3 views

arxiv.org/1107.0392

emergence human behavior science

shared by santecarloni on 07 Jul 11 - No Cached
LeopoldS liked it
  • santecarloni on 07 Jul 11
     
    ... proof that humanity is good?
  • LeopoldS on 16 Jul 11
     
    "The dataset contains practically all actions of all players of the MMOG Pardus since the game went online in 2004 [18]. Pardus is an open-ended online game with a world- wide player base of currently more than 370,000 people. Play- ers live in a virtual, futuristic universe in which they interact with others in a multitude of ways to achieve their self-posed goals [22]. Most players engage in various economic activities typically with the (self-posed) goal to accumulate wealth and status. Social and economical decisions of players are often strongly influenced and driven by social factors such as friend- ship, cooperation, and conflict." quite impressive ...
LeopoldS

Cellular and Network Contributions to Vestibular Signal Processing: Impact of Ion Condu... - 3 views

www.jneurosci.org/...8359.abstract

PHY AI bio technology

shared by LeopoldS on 25 Jun 11 - No Cached
  • LeopoldS on 25 Jun 11
     
    looks like very nice research - can we implement a technique inspired by this on a landing spacecraft?
jcunha

Missing link in metal physics explains Earth's magnetic field - 0 views

phys.org/...al-physics-earth-magnetic.html

PHY science

shared by jcunha on 29 Jan 15 - No Cached
  • jcunha on 29 Jan 15
     
    In a work published on Nature (http://www.nature.com/nature/journal/v517/n7536/full/nature14090.html#affil-auth) a new DFT based simulation of convection in Earth's Core iron shows that electron-electron scattering has a similar contribution to electron's thermal vibration. The outcome is that using the old dynamo theory the simulation matches the Earth magnetic field experimental results, solving an 80 years old puzzle.
  • Thijs Versloot on 29 Jan 15
     
    Yay to science! I'm always intrigued by related experiments that try to measure material properties at the GPa range. Especially, the efforts of reaching 'metallic hydrogen' (http://en.wikipedia.org/wiki/Metallic_hydrogen), requiring pressures above 25GPa at which hydrogen becomes conductive. It is thought that gas giant planets could have such a core, but no-one has been able to produce/verify this theory as off yet.
annaheffernan

Plasmons excite hot carriers - 1 views

physicsworld.com/...plasmons-excite-hot-carriers

science PHY

shared by annaheffernan on 11 Jul 14 - No Cached
  • annaheffernan on 11 Jul 14
     
    The first complete theory of how plasmons produce "hot carriers" has been developed by researchers in the US. The new model could help make this process of producing carriers more efficient, which would be good news for enhancing solar-energy conversion in photovoltaic devices.
  • LeopoldS on 13 Jul 14
     
    I did not read the paper but what is further down written in the article, does not give much hope that this actually gives much more insight than what we had nor that it could be used in any way to improve current PV cells soon: e.g. "To fully exploit these carriers for such applications, researchers need to understand the physical processes behind plasmon-induced hot-carrier generation. Nordlander's team has now developed a simple model that describes how plasmons produce hot carriers in spherical silver nanoparticles and nanoshells. The model describes the conduction electrons in the metal as free particles and then analyses how plasmons excite hot carriers using Fermi's golden rule - a way to calculate how a quantum system transitions from one state into another following a perturbation. The model allows the researchers to calculate how many hot carriers are produced as a function of the light frequency used to excite the metal, as well as the rate at which they are produced. The spectral profile obtained is, to all intents and purposes, the "plasmonic spectrum" of the material. Particle size and hot-carrier lifetimes "Our analyses reveal that particle size and hot-carrier lifetimes are central for determining both the production rate and the energies of the hot carriers," says Nordlander. "Larger particles and shorter lifetimes produce more carriers with lower energies and smaller particles produce fewer carriers, but with higher energies."
Daniel Hennes

Google Just Open Sourced the Artificial Intelligence Engine at the Heart of Its Online ... - 2 views

www.wired.com/...artificial-intelligence-engine

technology AI

shared by Daniel Hennes on 10 Nov 15 - No Cached
  • Daniel Hennes on 10 Nov 15
     
    TensorFlow is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them. The flexible architecture allows you to deploy computation to one or more CPUs or GPUs in a desktop, server, or mobile device with a single API. TensorFlow was originally developed by researchers and engineers working on the Google Brain Team within Google's Machine Intelligence research organization for the purposes of conducting machine learning and deep neural networks research, but the system is general enough to be applicable in a wide variety of other domains as well.
  • Paul N on 11 Nov 15
     
    And the interface even looks a bit less retarded than theano
aborgg

A New Era in Stretchable Electronics - 1 views

futurism.com/rs-and-stretch-like-an-octopus

stretchable electronics robotic skin conductive

shared by aborgg on 10 Mar 16 - No Cached
  • aborgg on 10 Mar 16
     
    Soft Robots Scientists from Cornell University and the Italian Technology Institute in Pontedera have developed an elastic robotic skin that is able to stretch up to five times its size, change colors, and even detect pressure. The luminescent skin, partly funded by the Army and Air Force's research wings, is comprised of different kinds of specialized silicone, making it flexible and soft.
  • aborgg on 10 Mar 16
     
    related video here: http://imgur.com/gallery/q57U40Y
Alexander Wittig

Calling Bullshit - 2 views

callingbullshit.org/index.html

science

shared by Alexander Wittig on 27 Feb 17 - No Cached
LeopoldS and jcunha liked it
  • Alexander Wittig on 27 Feb 17
     
    A college course at University of Washington on "Calling Bullshit". We should invite them to give a lunch lecture at ESA... Our aim in this course is to teach you how to think critically about the data and models that constitute evidence in the social and natural sciences. While bullshit may reach its apogee in the political domain, this is not a course on political bullshit. Instead, we will focus on bullshit that comes clad in the trappings of scholarly discourse. Our learning objectives are straightforward. After taking the course, you should be able to: * Remain vigilant for bullshit contaminating your information diet. * Recognize said bullshit whenever and wherever you encounter it. * Figure out for yourself precisely why a particular bit of bullshit is bullshit. * Provide a statistician or fellow scientist with a technical explanation of why a claim is bullshit. * Provide your crystals-and-homeopathy aunt or casually racist uncle with an accessible and persuasive explanation of why a claim is bullshit. We will be astonished if these skills do not turn out to be among the most useful and most broadly applicable of those that you acquire during the course of your college education.
  • LeopoldS on 01 Mar 17
     
    love it: "Politicians are unconstrained by facts. Science is conducted by press release. Higher education rewards bullshit over analytic thought. Startup culture elevates bullshit to high art. Advertisers wink conspiratorially and invite us to join them in seeing through all the bullshit - and take advantage of our lowered guard to bombard us with bullshit of the second order. The majority of administrative activity, whether in private business or the public sphere, seems to be little more than a sophisticated exercise in the combinatorial reassembly of bullshit. We're sick of it. It's time to do something, and as educators, one constructive thing we know how to do is to teach people. So, the aim of this course is to help students navigate the bullshit-rich modern environment by identifying bullshit, seeing through it, and combating it with effective analysis and argument."
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