Skip to main content

Home/ Advanced Concepts Team/ Group items tagged presentation

Rss Feed Group items tagged

Dario Izzo

Optimal Control Probem in the CR3BP solved!!! - 7 views

  •  
    This guy solved a problem many people are trying to solve!!! The optimal control problem for the three body problem (restricted, circular) can be solved using continuation of the secondary gravity parameter and some clever adaptation of the boundary conditions!! His presentation was an eye opener ... making the work of many pretty useless now :)
  • ...13 more comments...
  •  
    Riemann hypothesis should be next... Which paper on the linked website is this exactly?
  •  
    hmmm, last year at the AIAA conference in Toronto I presented a continuation approach to design a DRO (three-body problem). Nothing new here unfortunately. I know the work of Caillau, although interesting what is presented was solved 10 years ago by others. The interest of his work is not in the applications (CR3BP), but in the research of particular regularity conditions that unfortunately make the problem limited practically. Look also at the work of Mingotti, Russel, Topputo and other for the (C)RTBP. Smart-One inspired a bunch of researchers :)
  •  
    Topputo and some of the others 'inspired' researchers you mention are actually here at the conference and they are all quite depressed :) Caillau really solves the problem: as a one single phase transfer, no tricks, no misconvergence, in general and using none of the usual cheats. What was produced so far by other were only local solutions valid for the particular case considered. In any case I will give him your paper, so that he knows he is working on already solved stuff :)
  •  
    Answer to Marek: the paper you may look at is: Discrete and differential homotopy in circular restricted three-body control
  •  
    Ah! with one single phase and a first order method then it is amazing (but it is still just the very particular CRTBP case). The trick is however the homotopy map he selected! Why this one? Any conjugate point? Did I misunderstood the title ? I solved in one phase with second order methods for the less restrictive problem RTBP or simply 3-body... but as a strict answer to your title the problem has been solved before. Nota: In "Russell, R. P., "Primer Vector Theory Applied to Global Low-Thrust Trade Studies," JGCD, Vol. 30, No. 2", he does solve the RTBP with a first order method in one phase.
  •  
    I think what is interesting is not what he solved, but how he solved the problem. But, are means more important than end ... I dunno
  •  
    I also loved his method, and it looked to me that is far more general than the CRTBP. As for the title of this post, OK maybe it is an exageration as it suggests that no solution was ever given before, on the other end, as Marek would say "come on guys!!!!!"
  •  
    The generality has to be checked. Don't you think his choice of mapping is too specific? he doesn't really demonstrate it works better than other. In addition, the minimum time choice make the problem very regular (i guess you've experienced that solving min time is much easier than mass max, optimality-wise). There is still a long way before maximum mass+RTBP, Topputo et al should be re-assured :p Did you give him my paper, he may find it interesting since I mention the homotopy on mu but for max mass:)
  •  
    Joris, that is the point I was excited abut, at the conference HE DID present solutions to the maximum mass problem!! One phase, from LEO to an orbit around the moon .. amazing :) You will find his presentation on line.... (according to the organizers) I gave him the reference to you paper anyway, but no pdf though as you did not upload it on our web pages and I could not find it in the web. So I gave him some bibliography I had with be from the russians, and from Russell, Petropoulos and Howell, As far as I know these are the only ones that can hope to compete with this guy!!
  •  
    for info only, my phd, in one phase: http://pdf.aiaa.org/preview/CDReadyMAST08_1856/PV2008_7363.pdf I prefered Mars than the dead rock Moon though!
  •  
    If you send me the pdf I can give it to the guy .. the link you gave contains only the first page ... (I have no access till monday to the AIAA thingy)
  •  
    this is why I like this Diigo thingy so much more than delicious ...
  •  
    What do you mean by this comment, Leopold? ;-) Jokes apart: I am following the Diigo thingy with Google Reader (rss). Obviously, I am getting the new postings. But if someone later on adds a comment to a post, then I can miss it, because the rss doesn't get updated. Not that it's a big problem, but do you guys have a better solution for this? How are you following these comments? (I know that if you have commented an entry, then you get the later updates in email.) (For example, in google reader I can see only the first 5 comments in this entry.)
  •  
    I like when there are discussions evolving around entries
  •  
    and on your problem with the RSS Tamas: its the same for me, you get the comments only for entries that you have posted or that you have commented on ...
Ma Ru

Euroscience Open Forum 2010 - 2 views

shared by Ma Ru on 24 Apr 09 - Cached
LeopoldS liked it
  •  
    A conference ACT should consider going to.
  • ...4 more comments...
  •  
    Perhaps some of ACTers will find this conference interesting... One of the talks: "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" [Edit] Oh, I see someone has already posted this link... a year ago. Anyway, if anyone of you plans to go, let me know - I'll be around ;-)
  •  
    Just came back from ESOF 2010... I was on look for ACT agents undercover, but either they were not there or the cover was good enough... Anyway here's a few remarks from me (I could write a nice report... if you paid): 1) In general, to say that ESA was underrepresented on the conference as a whole is not enough (I guess ESA just failed to notice the event taking place). For instance, on the GMES presentation, ESA as such was not mentioned at all... at some point I started to wonder if ESA is actually involved in the project, but now I checked the website and apparently it is. On the other hand, GMES presentation was crap anyway, as after 1:15 of talking, I didn't gain any knowledge of what GMES is and what its contributions to the EU community will be. 2) There was a lot of talk about LHC and particle research (well, at least among those that I attended). Some of them were very good, some of them rather crap... 3) "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" talk - quite interesting, but focusing mainly on Science-to-Wide Public and Science-to-Journalists communication. Not really on Science-to-Science (as in Ariadnet). There was quite an extensive discussion with the public. You may be interested that Nature is trying to stimulate Web 2.0 communication, running blog service, but also I think a kind of social network - perhaps you'd like to have a look. In general the conclusion was that Web 2.0 is not so useful for scientific communication because practising it requires TIME (blogs, etc.) and often some professional skills (podcasts/videocasts, etc.), and scientists have neither of these. This can be run on corporation level (like ESA does actually), but then it looses the "intimate" character. 4) "How much can robots learn?" talk... very nicely presented: understandable by the wide public, but conveying the message... which is something like "we can already make the robots do stuff absolutely imp
  •  
    Well, my comment was cut in half, and I don't feel like typing it again... the most important highlight from the rest is that the only presenter from ESA (ESTEC) did not show up on his talk because his department was undergoing some sort of audit on the same day :)
  •  
    Fantastic comment - or better report!! thanks very much Marek! Who was the supposed no-show speaker from ESA?
  •  
    Bernard Foing (he is actually one of the 8 ESA employees who have their own page on Wikipedia)...
  •  
    written almost entirely by a guy called a "quest for knowledge" ... who will this be????? :-)
santecarloni

[1105.1293] Eigengestures for natural human computer interface - 1 views

  •  
    We present the application of Principal Component Analysis for data acquired during the design of a natural gesture interface. We investigate the concept of an eigengesture for motion capture hand gesture data and present the visualisation of principal components obtained in the course of conducted experiments. We also show the influence of dimensionality reduction on reconstructed gesture data quality.
ESA ACT

Bruce McCall's faux nostalgia | Video on TED.com - 0 views

  •  
    interesting presentation on past ideas of the future ...
Christos Ampatzis

FP7 Space projects - Presentations - 1 views

  •  
    If anybody's interested, here are the presentations from all FP7 Space Projects presented at the "Let's Embrace Space" in Budapest. A hard-copy book with information is with Leopold and here: http://ec.europa.eu/enterprise/policies/space/research/publications/index_en.htm you can find brochures with information
Joris _

Prezi - Ideas matter. - 2 views

shared by Joris _ on 27 Mar 13 - Cached
  •  
    Prezi is a cloud-based presentation software that opens up a new world between whiteboards and slides. The zoomable canvas makes it fun to explore ideas and the connections between them. The result: visually captivating presentations that lead your audience down a path of discovery.
nikolas smyrlakis

The Scale of the Universe 2 - 3 views

shared by nikolas smyrlakis on 16 Feb 12 - No Cached
  •  
    bit 'popular science' but fun and maybe good for presentations
santecarloni

Was a metamaterial lurking in the primordial universe? - physicsworld.com - 1 views

  •  
    A scientist in the US is arguing that the vacuum should behave as a metamaterial at high magnetic fields. Such magnetic fields were probably present in the early universe, and therefore he suggests that it may be possible to test the prediction by observing the cosmic microwave background (CMB) radiation - a relic of the early universe that can be observed today.
Luís F. Simões

The Spray-On Antenna That Boosts Reception Using Zero Power - 1 views

  • Speaking at Google's new "Solve for X" event, Rhett Spencer from military technology firm Chamtech explained how the company has developed an aerosol spray that paints an antenna onto any surface, boosting local wireless reception without using any extra power.
  • the aerosol coats a surface with thousands of nanocapacitors. They somehow align themselves and act as a wireless antenna.
  •  
    random idea: how about using this thing as the "pheromone" to be by released by robots in a swarm... Recognizing an area as being of interest, for some reason, would lead to more "pheromones" being released there. This would in turn attract other robots to the area, by virtue of having also maximization of connectivity to the rest of the swarm as part of the navigation algorithm.
  •  
    If this works as they claim this would be really interesting. Still no clue how they might be able to make this work though! Anybody?
santecarloni

How To Build A Speech Jamming Gun - Technology Review - 1 views

  •  
    he drone of speakers who won't stop is an inevitable experience at conferences, meetings, cinemas and public libraries.  Today, Kazutaka Kurihara at the National Institute of Advanced Industrial Science and Technology in Tskuba and Koji Tsukada at Ochanomizu University, both in Japan, present a radical solution: a speech jamming device that forces recalcitrant speakers into submission. 
  •  
    ...must...not...make...the...obvious...ACT...meeting...joke...
  •  
    Unfortunately it won't work when it is most needed .... Read this: "Their tests also identify some curious phenomena. They say the gun is more effective when the delay varies in time and more effective against speech that involves reading aloud than against spontaneous monologue. Sadly, they report that it has no effect on meaningless sound sequences such as "aaaaarghhh".
LeopoldS

The future is bright for humanity - opinion - 05 March 2012 - New Scientist - 1 views

  •  
    This is almost word for word the title Andrés gave to the first presentation of the team to DG ten years ago ...
  •  
    There's a whole series of futuristic articles, may be worth having a look: http://www.newscientist.com/special/deep-future
LeopoldS

Warp Drive More Possible Than Thought, Scientists Say | Space.com - 1 views

  •  
    Sante, Andreas, Luzi, Pacome ... we need you: "But recently White calculated what would happen if the shape of the ring encircling the spacecraft was adjusted into more of a rounded donut, as opposed to a flat ring. He found in that case, the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA launched in 1977.

    Furthermore, if the intensity of the space warps can be oscillated over time, the energy required is reduced even more, White found.

    "The findings I presented today change it from impractical to plausible and worth further investigation," White told SPACE.com. "The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab.""
  •  
    To me, this looks a little bit like the claim "infinity minus one is a little bit less than infinity"...
  •  
    Luzi I miss you ...
Luís F. Simões

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

  • "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)."
  •  
    We made it to Slashdot's frontpage !!! :)
  •  
    Congratulations, gentlemen!
johannessimon81

Voyager I has officially entered interstellar space - 2 views

  •  
    NASA JPL presentation on how and when Voyager exited the Heliosphere about a year ago - fascinating!
  •  
    NASA doing a great job here - very good presentation at a perfect abstraction level. I recommend watching the whole record.
LeopoldS

Peter Higgs: I wouldn't be productive enough for today's academic system | Science | Th... - 1 views

  •  
    what an interesting personality ... very symathetic Peter Higgs, the British physicist who gave his name to the Higgs boson, believes no university would employ him in today's academic system because he would not be considered "productive" enough.

    The emeritus professor at Edinburgh University, who says he has never sent an email, browsed the internet or even made a mobile phone call, published fewer than 10 papers after his groundbreaking work, which identified the mechanism by which subatomic material acquires mass, was published in 1964.

    He doubts a similar breakthrough could be achieved in today's academic culture, because of the expectations on academics to collaborate and keep churning out papers. He said: "It's difficult to imagine how I would ever have enough peace and quiet in the present sort of climate to do what I did in 1964."

    Speaking to the Guardian en route to Stockholm to receive the 2013 Nobel prize for science, Higgs, 84, said he would almost certainly have been sacked had he not been nominated for the Nobel in 1980.

    Edinburgh University's authorities then took the view, he later learned, that he "might get a Nobel prize - and if he doesn't we can always get rid of him".

    Higgs said he became "an embarrassment to the department when they did research assessment exercises". A message would go around the department saying: "Please give a list of your recent publications." Higgs said: "I would send back a statement: 'None.' "

    By the time he retired in 1996, he was uncomfortable with the new academic culture. "After I retired it was quite a long time before I went back to my department. I thought I was well out of it. It wasn't my way of doing things any more. Today I wouldn't get an academic job. It's as simple as that. I don't think I would be regarded as productive enough."

    Higgs revealed that his career had also been jeopardised by his disagreements in the 1960s and 7
  •  
  •  
    interesting one - Luzi will like it :-)
LeopoldS

Sex differences in the structural connectome of the human brain - 0 views

  •  
    it seems that there are indications that we are differently wired .... Sex differences in human behavior show adaptive complementarity: Males have better motor and spatial abilities, whereas females have superior memory and social cognition skills. Studies also show sex differences in human brains but do not explain this complementarity. In this work, we modeled the structural connectome using diffusion tensor imaging in a sample of 949 youths (aged 8-22 y, 428 males and 521 females) and discovered unique sex differences in brain connectivity during the course of development. Connection-wise statistical analysis, as well as analysis of regional and global network measures, presented a comprehensive description of network characteristics. In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections. Analysis of these changes developmentally demonstrated differences in trajectory between males and females mainly in adolescence and in adulthood. Overall, the results suggest that male brains are structured to facilitate connectivity between perception and coordinated action, whereas female brains are designed to facilitate communication between analytical and intuitive processing modes.
  •  
    I like this abstract: sex, sex, sex, sex, SEX, SEX, SEX, SEX...!!! I wonder if the "sex differences" are related to gender-specific differences...
LeopoldS

NASA - NASA IT Summit - 2 views

  •  
    who of you IT guru's are going to stay up late to follow some of the presentations live?
  •  
    nobody interested? Ed? Francesco? Dario?
Luís F. Simões

Timelapse video of asteroid discoveries in our solar system from 1980-2010 (watch in 10... - 5 views

  •  
    Nice... Now I have a lame question: after you have discovered ~500k asteroids, all moving (I assume more or less) chaotically in that asteroid belt, how do you tell one from another?
  • ...1 more comment...
  •  
    hmm, not very chaotic indeed - laws of Kepler plus some perturbations.
  •  
    That's what I thought but when presented as a green "goo" in the video, it appears rather unordered... so I guess this is just an impression evoked by a not-to-scale presentation?
  •  
    It depends... orbits can be chaotic if the orbital period is in a resonance with Jupiter, although such orbits are not stable. Such configurations tend to get disrupted pretty quickly (in cosmic terms :P) http://en.wikipedia.org/wiki/Kirkwood_gap
Luís F. Simões

Picbreeder: Collaborative Interactive Art Evolution (Genetic Art) - 1 views

  •  
    Following up on our coffee-time discussion, here's an Evolutionary Algorithm where you are the fitness function, and evolution is guided by your subjective artistic sense. Start from scratch, or pick an existing image in the database, and start evolving. At every generation, you are presented with the individuals/images in the population. Pick the ones you like. Those will be the parents from which the next generation will be bred. Repeat, repeat... where do you get to? If you want to learn more about the science behind this, check the tutorial below by Kenneth Stanley, who is also this site's supervisor: http://dx.doi.org/10.1145/1830761.1830920
duncan barker

BBC News - Real life postage that just needs your e-mail address - 0 views

  •  
    Interesting - apparently in the future (already in the US) you dont have to have someones address to send them presents, cards or goods. All you need is to be friends with them on facebook!!!
1 - 20 of 105 Next › Last »
Showing 20 items per page