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LeopoldS

The San Francisco Declaration on Research Assessment (DORA) - 1 views

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    another attempt to address impact factors
Lionel Jacques

Solar Energy Generation in Three Dimensions - 1 views

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    A simple cube open at the top can increase the annual energy density generation by a factor (depending on the latitude) of 2 - 3.8 compared to a flat horizontal panel, versus an increase by a factor of 1.3 - 1.8 achieved from a flat panel using dual-axis tracking. Genetic algorithm are used to optimize the energy production in a day for arbitrarily shaped 3D solar cells confined to a given area footprint and total volume doi:10.1063/1.3308490 could be interesting to investigate
LeopoldS

An optical lattice clock with accuracy and stability at the 10-18 level : Nature : Natu... - 0 views

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    Progress in atomic, optical and quantum science1, 2 has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard3, 4, 5. Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks6, 7, their accuracy has remained 16 times worse8, 9, 10. Here we demonstrate a many-atom system that achieves an accuracy of 6.4 × 10−18, which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standard-stability and accuracy. More stable and accurate atomic clocks will benefit a wide range of fields, such as the realization and distribution of SI units11, the search for time variation of fundamental constants12, clock-based geodesy13 and other precision tests of the fundamental laws of nature. This work also connects to the development of quantum sensors and many-body quantum state engineering14 (such as spin squeezing) to advance measurement precision beyond the standard quantum limit.
LeopoldS

A Formula for Happiness - NYTimes.com - 1 views

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    beati pauperes spiritu :-) "Political junkies might be interested to learn that conservative women are particularly blissful: about 40 percent say they are very happy. That makes them slightly happier than conservative men and significantly happier than liberal women. The unhappiest of all are liberal men; only about a fifth consider themselves very happy." I think that there are many factors missing there that are just not asked possibly such as altruism as a source for happiness ...
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    According to The Beatles "Happiness is a warm gun"... To each his own, I guess. :-)
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    It really depends on one's values really. If your values don't follow the standard vanilla flavor then it all breaks down.
tvinko

Massively collaborative mathematics : Article : Nature - 28 views

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    peer-to-peer theorem-proving
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    Or: mathematicians catch up with open-source software developers :)
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    "Similar open-source techniques could be applied in fields such as [...] computer science, where the raw materials are informational and can be freely shared online." ... or we could reach the point, unthinkable only few years ago, of being able to exchange text messages in almost real time! OMG, think of the possibilities! Seriously, does the author even browse the internet?
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    I do not agree with you F., you are citing out of context! Sharing messages does not make a collaboration, nor does a forum, .... You need a set of rules and a common objective. This is clearly observable in "some team", where these rules are lacking, making team work inexistent. The additional difficulties here are that it involves people that are almost strangers to each other, and the immateriality of the project. The support they are using (web, wiki) is only secondary. What they achieved is remarkable, disregarding the subject!
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    I think we will just have to agree to disagree then :) Open source developers have been organizing themselves with emails since the early '90s, and most projects (e.g., the Linux kernel) still do not use anything else today. The Linux kernel mailing list gets around 400 messages per day, and they are managing just fine to scale as the number of contributors increases. I agree that what they achieved is remarkable, but it is more for "what" they achieved than "how". What they did does not remotely qualify as "massively" collaborative: again, many open source projects are managed collaboratively by thousands of people, and many of them are in the multi-million lines of code range. My personal opinion of why in the scientific world these open models are having so many difficulties is that the scientific community today is (globally, of course there are many exceptions) a closed, mostly conservative circle of people who are scared of changes. There is also the fact that the barrier of entry in a scientific community is very high, but I think that this should merely scale down the number of people involved and not change the community "qualitatively". I do not think that many research activities are so much more difficult than, e.g., writing an O(1) scheduler for an Operating System or writing a new balancing tree algorithm for efficiently storing files on a filesystem. Then there is the whole issue of scientific publishing, which, in its current form, is nothing more than a racket. No wonder traditional journals are scared to death by these open-science movements.
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    here we go ... nice controversy! but maybe too many things mixed up together - open science journals vs traditional journals, conservatism of science community wrt programmers (to me one of the reasons for this might be the average age of both groups, which is probably more than 10 years apart ...) and then using emailing wrt other collaboration tools .... .... will have to look at the paper now more carefully ... (I am surprised to see no comment from José or Marek here :-)
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    My point about your initial comment is that it is simplistic to infer that emails imply collaborative work. You actually use the word "organize", what does it mean indeed. In the case of Linux, what makes the project work is the rules they set and the management style (hierachy, meritocracy, review). Mailing is just a coordination mean. In collaborations and team work, it is about rules, not only about the technology you use to potentially collaborate. Otherwise, all projects would be successful, and we would noy learn management at school! They did not write they managed the colloboration exclusively because of wikipedia and emails (or other 2.0 technology)! You are missing the part that makes it successful and remarkable as a project. On his blog the guy put a list of 12 rules for this project. None are related to emails, wikipedia, forums ... because that would be lame and your comment would make sense. Following your argumentation, the tools would be sufficient for collaboration. In the ACT, we have plenty of tools, but no team work. QED
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    the question on the ACT team work is one that is coming back continuously and it always so far has boiled down to the question of how much there need and should be a team project to which everybody inthe team contributes in his / her way or how much we should leave smaller, flexible teams within the team form and progress, more following a bottom-up initiative than imposing one from top-down. At this very moment, there are at least 4 to 5 teams with their own tools and mechanisms which are active and operating within the team. - but hey, if there is a real will for one larger project of the team to which all or most members want to contribute, lets go for it .... but in my view, it should be on a convince rather than oblige basis ...
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    It is, though, indicative that some of the team member do not see all the collaboration and team work happening around them. We always leave the small and agile sub-teams to form and organize themselves spontaneously, but clearly this method leaves out some people (be it for their own personal attitude or be it for pure chance) For those cases which we could think to provide the possibility to participate in an alternative, more structured, team work where we actually manage the hierachy, meritocracy and perform the project review (to use Joris words).
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    I am, and was, involved in "collaboration" but I can say from experience that we are mostly a sum of individuals. In the end, it is always one or two individuals doing the job, and other waiting. Sometimes even, some people don't do what they are supposed to do, so nothing happens ... this could not be defined as team work. Don't get me wrong, this is the dynamic of the team and I am OK with it ... in the end it is less work for me :) team = 3 members or more. I am personally not looking for a 15 member team work, and it is not what I meant. Anyway, this is not exactly the subject of the paper.
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    My opinion about this is that a research team, like the ACT, is a group of _people_ and not only brains. What I mean is that people have feelings, hate, anger, envy, sympathy, love, etc about the others. Unfortunately(?), this could lead to situations, where, in theory, a group of brains could work together, but not the same group of people. As far as I am concerned, this happened many times during my ACT period. And this is happening now with me in Delft, where I have the chance to be in an even more international group than the ACT. I do efficient collaborations with those people who are "close" to me not only in scientific interest, but also in some private sense. And I have people around me who have interesting topics and they might need my help and knowledge, but somehow, it just does not work. Simply lack of sympathy. You know what I mean, don't you? About the article: there is nothing new, indeed. However, why it worked: only brains and not the people worked together on a very specific problem. Plus maybe they were motivated by the idea of e-collaboration. No revolution.
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    Joris, maybe I made myself not clear enough, but my point was only tangentially related to the tools. Indeed, it is the original article mention of "development of new online tools" which prompted my reply about emails. Let me try to say it more clearly: my point is that what they accomplished is nothing new methodologically (i.e., online collaboration of a loosely knit group of people), it is something that has been done countless times before. Do you think that now that it is mathematicians who are doing it makes it somehow special or different? Personally, I don't. You should come over to some mailing lists of mathematical open-source software (e.g., SAGE, Pari, ...), there's plenty of online collaborative research going on there :) I also disagree that, as you say, "in the case of Linux, what makes the project work is the rules they set and the management style (hierachy, meritocracy, review)". First of all I think the main engine of any collaboration like this is the objective, i.e., wanting to get something done. Rules emerge from self-organization later on, and they may be completely different from project to project, ranging from almost anarchy to BDFL (benevolent dictator for life) style. Given this kind of variety that can be observed in open-source projects today, I am very skeptical that any kind of management rule can be said to be universal (and I am pretty sure that the overwhelming majority of project organizers never went to any "management school"). Then there is the social aspect that Tamas mentions above. From my personal experience, communities that put technical merit above everything else tend to remain very small and generally become irrelevant. The ability to work and collaborate with others is the main asset the a participant of a community can bring. I've seen many times on the Linux kernel mailing list contributions deemed "technically superior" being disregarded and not considered for inclusion in the kernel because it was clear that
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    hey, just catched up the discussion. For me what is very new is mainly the framework where this collaborative (open) work is applied. I haven't seen this kind of working openly in any other field of academic research (except for the Boinc type project which are very different, because relying on non specialists for the work to be done). This raise several problems, and mainly the one of the credit, which has not really been solved as I read in the wiki (is an article is written, who writes it, what are the names on the paper). They chose to refer to the project, and not to the individual researchers, as a temporary solution... It is not so surprising for me that this type of work has been first done in the domain of mathematics. Perhaps I have an ideal view of this community but it seems that the result obtained is more important than who obtained it... In many areas of research this is not the case, and one reason is how the research is financed. To obtain money you need to have (scientific) credit, and to have credit you need to have papers with your name on it... so this model of research does not fit in my opinion with the way research is governed. Anyway we had a discussion on the Ariadnet on how to use it, and one idea was to do this kind of collaborative research; idea that was quickly abandoned...
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    I don't really see much the problem with giving credit. It is not the first time a group of researchers collectively take credit for a result under a group umbrella, e.g., see Nicolas Bourbaki: http://en.wikipedia.org/wiki/Bourbaki Again, if the research process is completely transparent and publicly accessible there's no way to fake contributions or to give undue credit, and one could cite without problems a group paper in his/her CV, research grant application, etc.
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    Well my point was more that it could be a problem with how the actual system works. Let say you want a grant or a position, then the jury will count the number of papers with you as a first author, and the other papers (at least in France)... and look at the impact factor of these journals. Then you would have to set up a rule for classifying the authors (endless and pointless discussions), and give an impact factor to the group...?
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    it seems that i should visit you guys at estec... :-)
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    urgently!! btw: we will have the ACT christmas dinner on the 9th in the evening ... are you coming?
H H

Heisenbergs Dog, the foundation of quantum computing - 1 views

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    A Heisenberg's dog is the central unit in a quantum computer that factors prime numbers. We report the outcome of a proof-of-principle Gedankenexperiment in which the number 3 was factored and good agreement was found both with an analytical theoretical prediction and with the results of a quantum Las Vegas calculation. Other future applications of Heisenberg's dog are hinted at. The anonymous reports of the referees and our reply to them are reproduced in appendix A and appendix B respectively.
Dario Izzo

File Compression: New Tool for Life Detection? - 4 views

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    As mentioned today during coffee .... we could think to link this to source localization
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    Not sure by what you mean by source localisation, but this using gzip to discern "biological" from "non-biological" images seems to me *very* tricky... I mean, there's a lot of other factors that may affect compressibility of an image than just mere "regularity" of the pattern, and if they haven't controlled for these, this is just bullsh1t... (For instance did they use the same imaging device to take those images? What about lighting conditions and exposure? etc). The apostle of sometimes surprising uses of compression is prof. Shmidhuber from IDSIA...
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    I completely agree with you..... still if you have one instrument on board the spacecraft and your picture compressibility is a noisy indicator of some interesting source .... we could try to perform some probabilistic reasoning
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    I think they (IDSIA-Schmidhuber) are planning on putting something about that also inside the Acta Futura paper...
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    Really, you think they'd target such a low impact factor publication? ;-P
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    you will all soon be begging to publish in Acta Futura! We will be bigger than Nature.
nikolas smyrlakis

Seasonality of mortality: Summer vacation link? - 0 views

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    Mortality rates in several Mediterranean countries decline in September, due in part to environmental factors but possibly linked to summer vacations. - What does this teach us?
Dario Izzo

What is the Computational Value of Finite Range Tunneling? - 4 views

shared by Dario Izzo on 11 Jan 16 - No Cached
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    Google quantum computer improves simulated annealing by a factor 10^8 (allegedly)
Marcus Maertens

Who needs qubits? Factoring algorithm run on a probabilistic computer | Ars Technica - 2 views

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    advantages: p-bits run on room temperature and are easier to connect than q-bit.
LeopoldS

Decreasing human body temperature in the United States since the industrial revolution ... - 1 views

shared by LeopoldS on 11 Jan 20 - No Cached
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    Nice paper and linked to so many other factors.... curious "The question of whether mean body temperature is changing over time is not merely a matter of idle curiosity. Human body temperature is a crude surrogate for basal metabolic rate which, in turn, has been linked to both longevity (higher metabolic rate, shorter life span) and body size (lower metabolism, greater body mass). We speculated that the differences observed in temperature between the 19th century and today are real and that the change over time provides important physiologic clues to alterations in human health and longevity since the Industrial Revolution."
fichbio

Bacteria's Social Media - 2 views

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    Perhaps when you think of bacterial communities you think of a flask full of rapidly dividing E. coli. But in non-lab conditions, bacteria grow in complex, heterogeneous communities composed of diverse microscopic organisms. In these communities, bacteria need a means to communicate with their kin, and they do this through a language known as quorum sensing (QS), where bugs secrete and detect factors that tell them whether they're surrounded by kin (and if so, how many there are).
Thijs Versloot

Nanophononic metamaterials to boost thermoelectric performance - 0 views

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    Thermoelectric materials can see their performance radically improved via the utilization of an array of 'nanoscale pillars,' according to new research from the University of Colorado Boulder. These tiny pillars, built directly onto the thermoelectric material, will reduce the heat flow through the material by a factor of two while not affecting the electrical flow.
Thijs Versloot

Hyperloop plan revealed by Elon Musk - 0 views

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    More details in the linked pdf file.. a low pressurized tube with pods floating on air cushions together with EM propulsion and braking.. cool, but probably not going to be build any day soon
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    The point of this was that California is already planning to build a train line the would cost ten times more than this and be maybe one quarter of the speed. If the plan is actually feasible with the budget, this could very well have a chance...
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    A similar idea existed in Switzerland as well, it was called Swissmetro (http://en.wikipedia.org/wiki/Swissmetro) and intended to reach a ridiculously small top speed of about 500km/h. It had the same fate as Musk's idea will have soon: just a piece on the dump of history.
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    It would be great indeed, but even though the cost of the high speed train is a factor 10x higher, the prototype nature and hence relatively lower TRL of this system will probably not have it favoured. Best chance is that he develops a working prototype, one that might not even transport humans at the moment and for short distances, then maybe the project can take off
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    Actually, he was talking about a prototype: "I am somewhat tempted to at least make a demonstration prototype," Musk said in a conference call with reporters on Monday. "Perhaps I'll create a sub-scale version that's operating, and then hand it over to somebody else." "I think I'll probably end up doing that," he said. http://allthingsd.com/20130812/elon-musk-will-likely-build-his-own-hyperloop-prototype/
Thijs Versloot

Astronauts' hearts become more spherical in space - 0 views

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    The new findings come from a recent NASA study in which 12 astronauts aboard the ISS took ultrasound images of their hearts before, during, and after their six-month stint in space. What they found confirmed scientists' previous prediction: In microgravity, the human heart becomes more spherical by a factor of nearly 10 percent.
Luís F. Simões

The Truth About Google X: An Exclusive Look Behind The Secretive Lab's Closed Doors - 4 views

  • Space elevators, teleportation, hoverboards, and driverless cars: The top-secret Google X innovation lab opens up about what it does--and how it thinks.
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    Interesting insight indeed, I see quite some overlap with the ACT mantra, athough they have 250 people and an outdoor playground.. To Teller, this failure-loving lab has simply stepped into the breach. Small companies don't feel they have the resources to take moonshots. Big companies think it'll rattle shareholders. Government leaders believe there's not enough money, or that Congress will characterize a misstep or failure as a scandal. These days, when it comes to Hail Mary innovation, "Everyone thinks it's somebody's else's job," Teller says.
Tom Gheysens

The Moroccan flic-flac spider: A gymnast among the arachnids -- ScienceDaily - 5 views

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    New form of locomotion found in spiders. They say it could be used for a robot on Mars...don't immediately see how though. :)
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    Before it gets out of control... I hope you realise that quoting "Science Daily" in the context of science is pretty much like using Daily Mail as your reference news agency?
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    I was just going to post the same story. Here is BTW a video of the intended type of robot: https://www.youtube.com/watch?v=OHo32JrkDRk&feature=youtu.be
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    True Marek :) The article does quote a Journal Paper though ..... published in zootaxa: a staggering 0.9 impact factor journal!! And watching the video you immediately understand why :)
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    I of course watched the video and have trouble sleeping since.
johannessimon81

Breaking the optical diffraction limit by a factor 3-4... ideas for telescopes? - 0 views

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    In this article the authors describe an improvement of their optical microscope techniques for which some of the received a Nobel prize in the past. They achieve resolutions far beyond the optical diffraction limit which is supposed to limit detail resolution due to quantum-mechanical effects. Their techniques include structured illuminiation (producing interference patterns), switchable fluorescent markers as well as multi-frame super resolution enhancement. Authors are able to take a single image in about 0.3 seconds which allows the study of protein processes in the cell: http://spon.de/vgTb7 . Although it is hard to imagine the application of many of these techniques for telescopes (except for super resolution), I am wondering if any of this could help building telescopes with increased optical power or reduced weight. Any ideas..?
jcunha

Explosion-Generated Collapsing Vacuum Bubbles Reach 20,000 Kelvin - 1 views

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    "In a recent paper published in Physical Review Letters (PRL) Jérôme Duplat and Emmanuel Villermaux developed a method to generate centimeter-sized vacuum bubbles in water with miniature laser-driven explosions, and observed the flash of light produced as the bubble collapsed a not-fully-understood phenomenon known as sonoluminescence." Amazingly they concluded that the temperatrue inside the bubble as it collapses is about 26000 K. At this temperatures some (not me) argue for nuclear fusion... Intriguing stuff!!! Check the videos! Yet another test for the 'Experimental Physics Stagiare' :-)?
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    For sure no fusion, that starts appr. from about 20keV, not 20kK. Between both there is still a factor of 11500. What I would rather expect is that the conditions are not appropriate to work with Maxwellian distribution functions. If certain fusion products should be measurable, than this would rather confirm (but not proof) the hypothesis that they do not have Maxwellians but something close to monoenergetic. But most probably they will not measure fusion products, hence no fusion, hence no confusion.
Joris _

Spaceflight Now | Breaking News | Space agencies tackle waning plutonium stockpiles - 2 views

  • For every 100 watts of heat that I've got, the best I can do is get 8 watts of electricity
  • NASA is developing an Advanced Stirling Radioisotope Generator to improve the efficiency by a factor of four
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