Skip to main content

Home/ Advanced Concepts Team/ Group items tagged engine

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Luzi Bergamin

YouTube - Aircraft Maker to Make A Test Run - 1 views

www.youtube.com/watch

technology aircraft aerospace

shared by Luzi Bergamin on 29 Oct 10 - No Cached
  • Luzi Bergamin on 29 Oct 10
     
    A computer technician from Nairobi builds his own aircraft from scratch, using information on aerospace engineering available on internet... Idea for African spachteln programs??
Luís F. Simões

heat shields: NASA's Orion capsule vs. SpaceX's Dragon capsule - 0 views

neil.fraser.name/09

re-entry shielding design optimization spacex nasa

shared by Luís F. Simões on 11 Dec 10 - No Cached
  • NASA has 50 years of experience with reentry capsules, but is fearful of trying something new. SpaceX has no reentry experience and chooses the most efficient engineering approach. Guess whose capsule is overweight and still sitting on the ground? Guess whose capsule completed a successful first flight yesterday?
  • Dario Izzo on 12 Dec 10
     
    Powerful contrast between the two pictures!!
Ma Ru

Body from scratch - 3 views

edition.cnn.com/video

bio technology

shared by Ma Ru on 24 Feb 10 - Cached
pacome delva liked it
  • Ma Ru on 24 Feb 10
     
    Crazy, crazy, craaaazyyyyy!!!
  • nikolas smyrlakis on 25 Feb 10
     
    the "engineered ear" is awesome
pacome delva

Better Nanotubes May Be on the Way -- Fox 2009 (1210): 3 -- ScienceNOW - 1 views

sciencenow.sciencemag.org/...3

phy nan carbon_nanotubes

shared by pacome delva on 14 Dec 09 - Cached
  • Success at building large amounts of inexpensive nanotubes opens the door for lighter, faster car frames; affordable space vehicles; and ultralightweight armor. Or on a smaller level, BNNTs could be used with pinpoint precision to attack cancer cells by sticking to tumors, absorbing neutrons from a targeted beam, and generating localized alpha radiation to kill the cancer. "This is the start of a revolution in materials," says Dennis Bushnell, a NASA engineer who has watched the work closely in the hopes of using BNNTs for space vehicles.
LeopoldS

IISC - International Institute of Space Commerce - 5 views

www.iisc.im/publications.asp

reports science engineering space

shared by LeopoldS on 07 Jan 10 - Cached
Nicholas Lan liked it
  • LeopoldS on 07 Jan 10
     
    interesting collection / source of reports linked to space ...
Joris _

Why Computers Can't Mimic The Brain - Forbes.com - 3 views

www.forbes.com/...ology-breakthroughs-brain.html

BIO brain

shared by Joris _ on 06 Dec 09 - No Cached
  • engineers seem to have a diminished ability to understand biology
  • Remember them the next time you read a story claiming some brain-like accomplishment of a computer. The only really human thing these programs are doing is attracting attention to themselves
Francesco Biscani

Pi Computation Record - 4 views

bellard.org/pi2700e9

inf

shared by Francesco Biscani on 06 Jan 10 - Cached
  • Francesco Biscani on 06 Jan 10
     
    For Dario: the PI computation record was established on a single desktop computer using a cache optimized algorithm. Previous record was obtained by a cluster of hundreds of computers. The cache optimized algorithm was 20 times faster.
  • ...6 more comments...
  • Ma Ru on 06 Jan 10
     
    Teeeeheeeeheeee... assembler programmers greet Java/Python/Etc. programmers :)
  • Dario Izzo on 07 Jan 10
     
    And he seems to have done everything in his free time!!! I like the first FAQ.... "why did you do it?"
  • nikolas smyrlakis on 07 Jan 10
  • LeopoldS on 07 Jan 10
     
    did you read any of the books he recommends? suggest: Modern Computer Arithmetic by Richard Brent and Paul Zimmermann, version 0.4, November 2009, Full text available here. The Art of Computer Programming, volume 2 : Seminumerical Algorithms by Donald E. Knuth, Addison-Wesley, third edition, 1998. More information here.
  • LeopoldS on 07 Jan 10
     
    btw: we will very soon have the very same processor in the new iMac .... what record are you going to beat with it?
  • Francesco Biscani on 08 Jan 10
     
    Zimmerman is the same guy behind the MPFR multiprecision floating-point library, if I recall correctly: http://www.mpfr.org/credit.html I've not read the book... Multiprecision arithmetic is a huge topic though, at least from the scientific and number theory point of view if not for its applications to engineering problems. "The art of computer programming" is probably the closest thing to a bible for computer scientists :)
  • Francesco Biscani on 08 Jan 10
     
    "btw: we will very soon have the very same processor in the new iMac .... what record are you going to beat with it?" Fastest Linux install on an iMac :)
  • Juxi Leitner on 08 Jan 10
     
    "Fastest Linux install on an iMac :)" that is going to be a though one but a worthy aim! ""The art of computer programming" is probably the closest thing to a bible for computer scientists :)" yep! Programming is art ;)
Francesco Biscani

The End Of Gravity As a Fundamental Force - 6 views

science.slashdot.org/...Gravity-As-a-Fundamental-Force

phy

shared by Francesco Biscani on 11 Jan 10 - Cached
LeopoldS liked it
  • Francesco Biscani on 11 Jan 10
     
    "At a symposium at the Dutch Spinoza-instituut on 8 December, 2009, string theorist Erik Verlinde introduced a theory that derives Newton's classical mechanics. In his theory, gravity exists because of a difference in concentration of information in the empty space between two masses and its surroundings. He does not consider gravity as fundamental, but as an emergent phenomenon that arises from a deeper microscropic reality. A relativistic extension of his argument leads directly to Einstein's equations."
  • ...8 more comments...
  • Dario Izzo on 12 Jan 10
     
    Diffcult for me to fully understand / believe in the holographic principle at macroscopical scales ... potentially it looks though as a revolutionary idea.....
  • pacome delva on 13 Jan 10
     
    never heard about it... seems interesting. At first sight it seems that it is based on fundamental principle that could lead to a new phenomenology, so that could be tested. Perhaps Luzi knows more about this ? Did we ever work on this concept ?
  • Luzi Bergamin on 13 Jan 10
     
    The paper is quite long and I don't have the time right now to read it in detail. Just a few comments: * We (ACT) definitely never did anything in this direction? But: is there a new phenomenology? I'm not sure, if the aim is just to get Einstein's theory as emergent theory, then GR should not change (or only change in extreme conditions.) * Emergent gravity is not new, also Erik admits that. The claim to have found a solution appears quite frequently, but most proposals actually are not emergent at all. At least, I have the impression that Erik is aware of the relevant steps to be performed. * It's very difficult to judge from a short glance at the paper, up to which point the claims are serious and where it just starts to be advertisments. Section 6 is pretty much a collection of self-praise. * Most importantly: I don't understand how exactly space and time should be emergent. I think it's not new to observe that space is related to special canonical variables in thermodynamics. If anybody can see anything "emergent" in the first paragraphs of section 3, then please explain me. For me, this is not emergent space, but space introduced with a "sledge hammer." Time anyway seems to be a precondition, else there is nothing like energy and nothing like dynamics. * Finally, holography appears to be a precondition, to my knowledge no proof exists that normal (non-supersymmetric, non-stringy, non-whatever) GR has a holographic dual.
  • Luzi Bergamin on 13 Jan 10
     
    Update: meanwhile I understood roughly what this should be about. It's well known that BH physics follow the laws of theormodynamics, suggesting the existence of underlying microstates. But if this is true, shouldn't the gravitational force then be emergent from these microstates in the same way as any theromdynamical effect is emergent from the behavior of its constituents (e.g. a gas)? If this can be prooven, then indeed gravity is emergent. Problem: one has to proof that *any* configuration in GR may be interpreted as thermodynamical, not just BHs. That's probably where holography comes into the play. To me this smells pretty much like N=4 SYM vs. QCD. The former is not QCD, but can be solved, so all stringy people study just that one and claim to learn something about QCD. Here, we look at holographic models, GR is not holographic, but who cares... Engineering problems...
  • LeopoldS on 13 Jan 10
     
    is there any experimental or observational evidence that points to this "solution"?
  • Luzi Bergamin on 13 Jan 10
     
    Are you joking??? :D
  • pacome delva on 14 Jan 10
     
    I was a bit fast to say it could be tested... apparently we don't even know a theory that is holographic, perhaps a string theory (see http://arxiv.org/abs/hep-th/9409089v2). So very far from any test...
  • LeopoldS on 14 Jan 10
     
    Luzi, I miss you!!!
  • Luzi Bergamin on 14 Jan 10
     
    Leo, do you mean you liked my comment on your question more than Pacome's? Well, the ACT has to evolve and fledge, so no bullshitting anymore, but serious and calculating answers... :-) Sorry Pacome, nothing against you!! I just LOVE this Diigo because it gives me the opportunity for a happy revival of my ACT mood.
  • pacome delva on 14 Jan 10
     
    haha, today would have been great to show your mood... we had a talk on the connection between mind and matter !!
Joris _

Space shuttles for sale - Short Sharp Science - New Scientist - 4 views

www.newscientist.com/...space-shuttles-for-sale.html

Space shuttle

shared by Joris _ on 19 Jan 10 - Cached
  • If an entire shuttle is beyond your budget, consider a main engine instead. NASA had hoped to charge up to $800,000 for these but lack of interest has forced it to slash the price. They are now available for free
  • Nicholas Lan on 19 Jan 10
     
    will it fit in diego's van?
Francesco Biscani

STLport: An Interview with A. Stepanov - 2 views

www.stlport.org/...StepanovUSA.html

computer science

shared by Francesco Biscani on 23 Mar 10 - Cached
  • Generic programming is a programming method that is based in finding the most abstract representations of efficient algorithms.
  • I spent several months programming in Java.
  • for the first time in my life programming in a new language did not bring me new insights
  • ...2 more annotations...
  • it has no intellectual value whatsoever
  • Java is clearly an example of a money oriented programming (MOP).
  • Francesco Biscani on 23 Mar 10
     
    One of the authors of the STL (C++'s Standard Template Library) explains generic programming and slams Java.
  • ...6 more comments...
  • Ma Ru on 24 Mar 10
     
    "Java is clearly an example of a money oriented programming (MOP)." Exactly. And for the industry it's the money that matters. Whatever mathematicians think about it.
  • Joris _ on 24 Mar 10
     
    It is actually a good thing that it is "MOP" (even though I do not agree with this term): that is what makes it inter-operable, light and easy to learn. There is no point in writing fancy codes, if it does not bring anything to the end-user, but only for geeks to discuss incomprehensible things in forums. Anyway, I am pretty sure we can find a Java guy slamming C++ ;)
  • Francesco Biscani on 24 Mar 10
     
    Personally, I never understood what the point of Java is, given that: 1) I do not know of any developer (maybe Marek?) that uses it for intellectual pleasure/curiosity/fun whatever, given the possibility of choice - this to me speaks loudly on the objective qualities of the language more than any industrial-corporate marketing bullshit (for the record, I argue that Python is more interoperable, lighter and easier to learn than Java - which is why, e.g., Google is using it heavily); 2) I have used a software developed in Java maybe a total of 5 times on any computer/laptop I owned over 15 years. I cannot name of one single Java project that I find necessary or even useful; for my usage of computers, Java could disappear overnight without even noticing. Then of course one can argue as much as one wants about the "industry choosing Java", to which I would counterargue with examples of industry doing stupid things and making absurd choices. But I suppose it would be a kind of pointless discussion, so I'll just stop here :)
  • Joris _ on 24 Mar 10
     
    "At Google, python is one of the 3 "official languages" alongside with C++ and Java". Java runs everywhere (the byte code itself) that is I think the only reason it became famous. Python, I guess, is more heavy if it were to run on your web browser! I think every language has its pros and cons, but I agree Java is not the answer to everything... Java is used in MATLAB, some web applications, mobile phones apps, ... I would be a bit in trouble if it were to disappear today :(
  • Dario Izzo on 24 Mar 10
     
    I personally do not believe in interoperability :)
  • Ma Ru on 24 Mar 10
     
    Well, I bet you'd notice an overnight disappearance of java, because half of the internet would vanish... J2EE technologies are just omnipresent there... I'd rather not even *think* about developing a web application/webservice/web-whatever in standard C++... is it actually possible?? Perhaps with some weird Microsoft solutions... I bet your bank online services are written in Java. Certainly not in PHP+MySQL :) Industry has chosen Java not because of industrial-corporate marketing bullshit, but because of economics... it enables you develop robustly, reliably, error-prone, modular, well integrated etc... software. And the costs? Well, using java technologies you can set-up enterprise-quality web application servers, get a fully featured development environment (which is better than ANY C/C++/whatever development environment I've EVER seen) at the cost of exactly 0 (zero!) USD/GBP/EUR... Since many years now, the central issue in software development is not implementing algorithms, it's building applications. And that's where Java outperforms many other technologies. The final remark, because I may be mistakenly taken for an apostle of Java or something... I love the idea of generic programming, C++ is my favourite programming language (and I used to read Stroustroup before sleep), at leisure time I write programs in Python... But if I were to start a software development company, then, apart from some very niche applications like computer games, it most probably would use Java as main technology.
  • Francesco Biscani on 24 Mar 10
     
    "I'd rather not even *think* about developing a web application/webservice/web-whatever in standard C++... is it actually possible?? Perhaps with some weird Microsoft solutions... I bet your bank online services are written in Java. Certainly not in PHP+MySQL :)" Doing in C++ would be awesomely crazy, I agree :) But as I see it there are lots of huge websites that operate on PHP, see for instance Facebook. For the banks and the enterprise market, as a general rule I tend to take with a grain of salt whatever spin comes out from them; in the end behind every corporate IT decision there is a little smurf just trying to survive and have the back covered :) As they used to say in the old times, "No one ever got fired for buying IBM". "Industry has chosen Java not because of industrial-corporate marketing bullshit, but because of economics... it enables you develop robustly, reliably, error-prone, modular, well integrated etc... software. And the costs? Well, using java technologies you can set-up enterprise-quality web application servers, get a fully featured development environment (which is better than ANY C/C++/whatever development environment I've EVER seen) at the cost of exactly 0 (zero!) USD/GBP/EUR... Since many years now, the central issue in software development is not implementing algorithms, it's building applications. And that's where Java outperforms many other technologies." Apart from the IDE considerations (on which I cannot comment, since I'm not a IDE user myself), I do not see how Java beats the competition in this regard (again, Python and the huge software ecosystem surrounding it). My impression is that Java's success is mostly due to Sun pushing it like there is no tomorrow and bundling it with their hardware business.
  • Joris _ on 24 Mar 10
     
    OK, I think there is a bit of everything, wrong and right, but you have to acknowledge that Python is not always the simplest. For info, Facebook uses Java (if you upload picture for instance), and PHP is very limited. So definitely, in company, engineers like you and me select the language, it is not a marketing or political thing. And in the case of fb, they come up with the conclusion that PHP, and Java don't do everything but complement each other. As you say Python as many things around, but it might be too much for simple applications. Otherwise, I would seriously be interested by a study of how to implement a Python-like system on-board spacecrafts and what are the advantages over mixing C, Ada and Java.
Ma Ru

Researcher Creates 'Facebook for Scientists' - 1 views

www.nytimes.com/...book-for-scientists-22081.html

inf Web 2.0 ariadnet science

shared by Ma Ru on 19 Mar 10 - Cached
  • Ma Ru on 19 Mar 10
  • ...4 more comments...
  • LeopoldS on 20 Mar 10
     
    and we are of course there since some time :-) and even have our own group in there ... think that Tobias has first discovered it our group is: https://www.researchgate.net/group/ESA_Advanced_Concepts_Team/ everybody welcome to join ... though Ariadnet is better
  • Ma Ru on 23 Mar 10
     
    So if I'm already on Ariadnet, there's no need for me to join this researchgate thingy? Pheew..
  • Luzi Bergamin on 23 Mar 10
     
    Very active group, it has exactly one member (Leo) and exactly zero (ZERO,0!!) posts since June 13, 2008!!! Well, sounds like a very typical ACT action in order to increase the key performance indicators :D.
  • Ma Ru on 23 Mar 10
     
    Oh come on Luzi, don't be over-pessimistic! It's just because all activity takes place on Ariadnet ;-)
  • nikolas smyrlakis on 24 Mar 10
     
    tsk tsk typical ex-ACT criticism.. Maybe for me too from next week;P
  • Luzi Bergamin on 24 Mar 10
     
    WRONG! You ignore the fact that I complained already while I was yet in the ACT!! Seriously: I clicked around in "ResearchGate" a little bit, couldn't find too many interesting things. Many scientists from India, Iran etc. desperately looking for contacts, retired engineers/scientists from industry that now remember that they were once at university and also quite a number of semi-crackpots. My honest conclusion: not a must. Btw: wish you a nice post-ACT depression! Keep a stiff upper lip, esp. in case you go back to Greece...
pacome delva

Fruit Fly Aerial Maneuver Explained - 1 views

focus.aps.org/st13

bio biomimicry fruit_fly

shared by pacome delva on 12 Apr 10 - Cached
LeopoldS liked it
  • Insects can execute flying feats more impressive than fighter jets, and a team of researchers has now learned the trick behind one of them. They used high speed video cameras and a new 3D reconstruction technique to show how fruit flies execute their acrobatic turns. As they report in the 9 April Physical Review Letters, despite the complex wing motions, a fly can execute quick pirouettes by adjusting just a single parameter that controls the difference between the way its left and right wings oscillate. The results may be relevant for engineers designing flight control strategies for tiny robotic insects for search-and-rescue and surveillance.
pacome delva

Girls Get Math: It's Culture That's Skewed - 2 views

www.livescience.com/...090601-gender-math.html

sociology math

shared by pacome delva on 19 Apr 10 - Cached
  • "There's a gender stereotype that boys are better at math than girls are, and stereotypes die very hard," Hyde told LiveScience. "Teachers and parents still believe that boys are better at math than girls are." The researchers provide several possible cultural factors keeping females from excelling in math, including classroom dynamics in which teachers pay more attention to boys, while even mathematically gifted girls are not nurtured. In addition, stereotypes may drive guidance counselors and others to discourage girls from taking engineering courses.
  • Nina Nadine Ridder on 26 Apr 10
     
    The guidance counselor at my high school discouraged me to study physics but was very excited when I was contemplating to become a teacher. Maybe I should send her this article...
  • Luzi Bergamin on 26 Apr 10
     
    Oh yeah, real new!! And in the 90s it was obvious that girls are smarter but discriminated, today its obvious that the poor boys are neglected; some years ago female teachers were proven to discriminate even stronger against girls than male teachers and today politicians demand more male teachers... because they would pay more attention to the neglected boys! Great, that's what I like about sociological research, every couple of years one can sell the same old story again and again and again... sorry, I'm in a real bullshitter mood today!
  • Nicholas Lan on 27 Apr 10
     
    gotta agree with luzi here. girls at secondary school in the UK have been outperforming boys for years now after numerous government programmes. As to guidance counsellors - if they were any good at guidance wouldn't they have better jobs?
pacome delva

Novel negative-index metamaterial bends light 'wrong' direction - 1 views

www.sciencedaily.com/...100422153939.htm

phy nan metamaterials

shared by pacome delva on 23 Apr 10 - Cached
  • the first negative index metamaterial to operate at visible frequencies
  • By engineering a metamaterial with such properties, we are opening the door to such unusual -- but potentially useful -- phenomena as superlensing (high-resolution imaging past the diffraction limit), invisibility cloaking, and the synthesis of materials index-matched to air, for potential enhancement of light collection in solar cells
  • Luzi Bergamin on 23 Apr 10
     
    I forwarded the link to my experimental colleagues and here is the comment from Sergei (the master himself:) "this is what Igor has been doing - an array of plasmonic nanocables. This basically works as a wire-medium slab. All their epsilon and mu are rubbish." * If Sergei is as strict as in this comment, then it IS rubbish. He's not one of the notorious complainer (as e.g. myself.) * Please DO NOT FORWARD this to anybody else, Sergei's comment is NOT FOR PUBLIC USE!
  • Luzi Bergamin on 23 Apr 10
     
    UPDATE: I had a short chat with Sergei and Pekka, Sergei noticed that there is an increasing number of papers on metamaterials, especially in Nature and Science, which are simply wrong, this one being an example. * The idea is based on a very well known effect of wired media. What appears to be interesting about this paper is that they manage to make an optical analogue with aparently low losses. This could be interesting. * The whole interpretation as NIM, "wrong" refraction etc. is total nonsense.
  • pacome delva on 23 Apr 10
     
    wow, good to know ! But for the privacy you should be aware that this is a public group, so anyone has access to our comments i think !
pacome delva

Synthetic Genome Brings New Life to Bacterium - 0 views

www.sciencemag.org/...958

bio genomics ethics

shared by pacome delva on 21 May 10 - Cached
LeopoldS liked it
  • For 15 years, J. Craig Venter has chased a dream: to build a genome from scratch and use it to make synthetic life. Now, he and his team at the J. Craig Venter Institute (JCVI) in Rockville, Maryland, and San Diego, California, say they have realized that dream.
  • "One thing is sure," Boeke says. "Interesting creatures will be bubbling out of the Venter Institute's labs."
  • pacome delva on 21 May 10
     
    wow, a big step in genomics...!
  • Ma Ru on 21 May 10
     
    But isn't it just yet another word abuse? From what I understand, they just synthesised a genome identical to the one of an existing bacteria... while undoubtedly nice work, this is *very* far from "creating life from scratch"... The fact that you are able to copy something, doesn't mean you understand how it works...
  • pacome delva on 27 May 10
     
    well of course we are far from engineering specific functions, and this is just a copy of a function that already existed. However it is quite impressive and the first time it is done. And the challenge here is not really to "copy" the ADN, but the fact that it works... in other words it is not because you copy the ADN identically that the phenotype (traduction of the ADN) will be the same, which is the case in this experiment.
pacome delva

Commercial quantum cryptography system hacked - 0 views

physicsworld.com/...42667

phy quantum_cryptography

shared by pacome delva on 21 May 10 - Cached
LeopoldS liked it
  • quantum cryptography, according to some engineers, is not without its faults. In a preprint submitted late last week to arXiv, Hoi-Kwong Lo and colleagues at the University of Toronto, Canada, claim to have hacked into a commercial quantum cryptography system by exploiting a certain practical “loophole”.
pacome delva

Malagasy Spiders Spin the World's Toughest Biological Material - ScienceNOW - 0 views

news.sciencemag.org/...y-spiders-spin-the-worlds.html

bio biomaterials spiders

shared by pacome delva on 04 Jan 11 - No Cached
  • Like an engineer accounting for a skyscraper swaying in the wind, Madagascar's Darwin's bark spider (Caerostris darwini) spins enormous, river-spanning webs that stretch and contract as the trees to which they're anchored bend this way and that. A new study finds that this spider's silk is the toughest biomaterial yet discovered.
  • The spiders' colossal orb webs can span up to 2.8 square meters and are anchored by threads as long as 25 meters.
Luís F. Simões

The Fallout of a Helium-3 Crisis : Discovery News - 3 views

news.discovery.com/...fall-of-a-helium-3-crisis.html

helium crisis moon mining

shared by Luís F. Simões on 22 Feb 11 - No Cached
  • So short in fact, that last year when the looming crisis, which reporters had been covering for years, became official, the price of helium-3 went from $150 per liter to $5,000 per liter.
  • The science, medical and security uses for helium-3 are so diverse that the crisis banded together a hodge-podge of universities, hospitals and government departments to try and find workable alternatives and engineer ways to recycle the gas they do have.
  • Luís F. Simões on 22 Feb 11
     
    So, which shall it be? Are we going to increase the production of hydrogen bombs, or can we finally go back to the Moon (http://en.wikipedia.org/wiki/Helium-3#Extraterrestrial_supplies) ?
  • dejanpetkow on 23 Feb 11
     
    None of these. Either you recycle, or you take it from natural sources on Earth. Although most people don't know - there is plenty of natural He3 on Earth. It's just nonsens to use it for energy production (in fusion reactors) since the energy belance for getting the He3 from these source on Earth is just negative. Or you try to substitute He3.
« First ‹ Previous 141 - 160 of 227 Next › Last »
Showing 20▼ items per page