Tuesday, December 13, 2005
Wednesday, September 21, 2005
From the Circuits newsletter v5 n9 (Sept 2005)
PROCEEDINGS OF THE IEEE FOCUSES ON SILICON GERANIUM
The September issue of Proceedings of the IEEE (v. 93, no. 9) provides a detailed analysis of the impact of silicon geranium on commercial products since its integration with complementary metal oxide semiconductors (CMOS). The issue focuses on silicon geranium and advanced CMOS semiconductor compatibility, which has led to the development of highly integrated single-chip designs with advanced bipolar performance. Paper topics include device physics, new processes, scaling issues, reliability, and device optimization for specific applications. Other key areas of interest are high-breakdown SiGe heterostructure bipolar transistors, low-cost derivatives, linearity and noise, modeling, design enablement, and circuit examples...
Don't you love spell check?
Thursday, September 01, 2005
Maybe these people don't know that local ham groups practice multiple times a year out in mobile units with generators and mobile rigs and antennas. It's purely voluntary -- they do it because they think it's important and they know they can help.
In fact, if you have an amateur radio license please volunteer. Here's more information from ARRL:
Hurricane Katrina Volunteer Signup Database Now Open (Aug 31, 2005) -- The Hurricane Katrina Disaster Communications Volunteer Registration & Message Traffic Database now is open. Site Administrator Joe Tomasone, AB2M, set up the database, and South Texas ARRL Section Emergency Coordinator Jerry Reimer, KK5CA, is handling volunteer coordination. This site is intended for Amateur Radio volunteers to sign up for communication support duty on behalf of Hurricane Katrina relief and recovery efforts in Louisiana and Mississippi. Full Story
(link courtesy of WB3DAJ via e-mail)
Wednesday, August 31, 2005
Thursday, August 25, 2005
Sean at 6:14 pm, August 24th, 2005
Over the last fifteen years, the way that physicists communicate research results has been revolutionized by arxiv.org, the preprint server devised by Paul Ginsparg (formerly xxx.lanl.gov). Any time you write a paper, you send it to the arxiv, where its existence is beamed to the world the next day, and it is stored there in perpetuity. Along with the SPIRES service at SLAC, which keeps track of which papers have cited which other papers, physicists have a free, flexible, and easy-to-use web of literature that is instantly accessible to anyone. Most people these days post to the arxiv before they even send their paper to a journal, and some have stopped submitting to journals altogether. (I wish they all would, it would cut down on that annoying refereeing we all have to do.) And nobody actually reads the journals — they serve exclusively as ways to verify that your work has passed peer review.
So it’s exciting to see the introduction of trackbacks to the abstracts at arxiv.org. As blog readers know, an individual blog post can inform other blog posts that it is talking about them by leaving a “trackback” or “pingback” — basically, a way of saying “Hey, I’m talking about that stuff you said.” This helps people negotiate their way through the tangles of the blogosphere along threads of common interest. Now your blog post can send trackbacks to the abstracts of papers at the arxiv! Here’s a test: I will link to my most recent paper. If it works as advertised, the trackback will appear automatically, due to the magic of WordPress.
Now, if you write a paper and people comment on it on their blogs, that fact will be recorded right there at the abstract on arxiv.org. Drawing us one step closer to the use of blogs as research tools.
Tuesday, August 23, 2005
From Rice and supported in part by NSF, this database collects scientific articles researching environmental health and safety aspects of nanoparticles (read press release). From a librarian point of view, it leaves a little to be desired. In fact, it might be quite difficult to find the full text of the article based on the citation given. A guide to the abbreviations use for journals might be helpful (hmm, maybe they're using the pubmed ones?). I'd love to see the DOI and a link to the pubmed record (it does list PMID, though, so you can find the article that way if you recognize the number). For the articles on environmental concerns, there's no PMID... Hmm. Don't see a list of journals referenced or a methodology of how articles are identified.
Anyway, looks like a good first step and will no doubt be useful to those working in the area.
Thursday, August 18, 2005
I’ve totally been enthralled by Make since I heard about it a couple of months ago. It’s a quarterly magazine from O’Reilly that basically features life hacks. It’s how to actually make things…
The Washington Post article basically says that you have to be an electronics genius to use a multimeter. Personally, I think everyone should learn that in high school (if they didn’t already learn it in elementary). Honestly, though, you don’t have to be a teenage boy to get this magazine. I think this is really an extension of the movement that brought us junkyard wars and monster garage and I’m all for it.
Thursday, August 11, 2005
Wednesday, June 22, 2005
Author: By VLADIMIR ISACHENKOV,The Associated Press
Wednesday, June 22, 2005; 12:20 PM
This vehicle was being launched to demonstrate a controlled flight of a solar sail. Solar sails are a means of spacecraft propulsion relying on pressure from sunlight. They would potentially work well for interstellar flight because they would allow the spacecraft to conserve fuel.
Apparently the booster rocket failed 83 seconds after launch. Readers may remember that this space vehicle was submarine launched (pretty cool if it works).
See the Cosmos 1 Blog for real time updates from Emily Lakdawalla, Project Operations Assistant and Image Processing Coordinator for Cosmos 1. There's no archive listing, so you have to page back to read from the pre-launch activities...
They say it's good to 20m in dense urban environments and doesn't have the multipath issues of A-GPS. Since it's going on signal strength, I'm guessing you'd probably want 4 sources for a reliable fix (two signals would give you two equally probable locations, a third would say which of the two, a fourth would make me happier-- especially if the other signals are coming from the same general direction). This does limit you to dense downtown areas -- but that's what it's made for. The blogger who first pointed this out mentions people moving and taking their transmitters with them.
Update: John Krumm from Microsoft Research recently presented a paper on this at MobiSys 2005, the Third International Conference on Mobile Systems, Applications and Services, held June 6-8 in Seattle.... apparently signal strength doesn't work as well as "other aspects of signal quality" hmm? The paper will appear in ACM here for subscribers.
Update 6/30: I just noticed that the July 2005 issue of IEEE Signal Processing (link for subscribers to Xplore) has a large special section on positioning in wireless networks.
Monday, June 20, 2005
On Weekend America this past weekend, the hosts spoke with MIT professor Neil Gershenfeld about the Fab Lab project. The hope is that users will be able to make one off machines to fit their needs.
You know, I really respect Professor Gershenfeld who laments the disconnect between working with your mind and working with your hands... to go to a liberal arts college or learn to weld in a trade school (the assumption that you can't do both). What he's trying to do with this fab lab is to reconnect thinking with doing. Actually making something is a worthwhile pursuit.
Thursday, June 16, 2005
This little robot looks like something out of a Douglas Adams book... but it makes a lot of sense to have a "mini autonomous extravehicular robotic camera" to be able to check out parts of the spacecraft that can't be seen by a camera on a stick. It uses a "rechargeable xenon gas propulsion system" -- aack, that's expensive. Xenon, if I recall correctly, is pulled out of the atmosphere, but you have to suck up a lot of atmosphere to get a little bit of Xenon. So with this, the imaging is the easy part the docking station and propulsion are slightly more tricky.
Here's the NASA page for the little guy.
Tuesday, May 24, 2005
British Antarctic Survey and the University of Bath have installed a remote sensing radar in Antarctica that aid in the investigation of the Mesosphere. It also tracks the many meteors that burn up in the mesosphere.
Tuesday, May 17, 2005
The upshot is that a US company has developed a super-oxgenated water that is perfectly drinkable, but kills bacteria, viruses, and spores. Cool, right? Shelf-life of over a year.
This reminds me of a short story in which an ice that sank was invented. Short story short-- it took over the world and killed the planet. So, I guess the solution to pollution with the super water is dilution, but it still wouldn't be good for your fish tank.
Monday, April 18, 2005
I like NEO stories but this is pretty funny. It's a slow news day when newspapers publish panic headlines about NEOs that have a 1 in 45 chance of hitting the earth in the next 25 years. Wikipedia has this article on the Torino Scale.
With all of these scales, whether from DHS or the meteorologist, they're supposed to clarify the actual threat, but the number of words it takes to explain a mango warning probably out weigh the original story.
...The colors haven't changed from the old system, but the explanation of what each color means has. Asteroids in the green section used to be deemed 'events meriting careful monitoring,' but now are considered 'normal.' And a level 6 object was described as capable of causing 'global catastrophe.' Now these, too, only merit the concern of astronomers...Not all the changes paint a rosier picture. Under the old system, a level 10 warning used to be described as 'causing global climatic disaster.' The new description reads 'a certain collision capable of causing global climatic catastrophe that may threaten the future of civilization as we know it.'
Ok, so ADS (the NASA Astrophysics Data System) is really THE astro database. They've had e-mail alerts, but unfortunately not for affiliations. Now you can subscribe to a search in your feed reader and be kept up to date without filling your in box. Still no affiliations, but great nonetheless.
Thursday, April 14, 2005
Robert Miner. "The Importance of MathML to Mathematics Communication." Notices of the AMS v52 n5 (May 2005): 532-8.
One of my lines of inquiry has been how to search math -- I mean really search it. What if you don't know what the equation is called? Why can't you do a substructure search like you do in chemistry? Shouldn't math be easier to search than chemistry? Instead, it's worse that image searching.
MathML is supposed to fix some of these things. Miner is very enthusiastic in extolling its virtues. The only problem is that mathematicians don't seem to be jumping on the bandwagon. They seem to really like LaTeX.
One physicist has created some plugins for WordPress and Movabletype to convert TeX equations to MathML. Cool...
Thursday, April 07, 2005
He's a technology writer, not a scientist, but Pogue gives these new batteries a test. Not bad, but probably not as useful as NiMH. The Cnet article has a little more on the actual technology involved. If I ever find the relevant patents, I'll update this.
Wednesday, April 06, 2005
"On April 8th in North America crescent-shaped sunbeams will dapple the ground during a partial solar eclipse." There's a timetable from NASA's GSFC that tells you when it will happen in your neck of the woods. People in the south will have a much better show but this article points out some neat tricks.
Thursday, March 31, 2005
"These mysterious objects are dark-energy stars, physicist claims." Isn't that something out of StarWars? So the idea is that stars don't collapse and become black holes; rather they become filled with dark energy. The author says that this explains some of the event horizon wierdness. The original article is: Chapline G. Arxiv, http://xxx.arxiv.org/abs/astro-ph/0503200 (2005).
Monday, March 28, 2005
Thursday, March 24, 2005
Friday, March 11, 2005
While supporting basic science research is indeed essential for protecting national security, can that be our sole primary motivation for pursuing knowledge of the natural world? When asked by Congress whether Fermilab, the expensive atomic accelerator, would contribute to the national defense, its founding director replied that the contribution would be "… not to the defense of the nation, but rather to what made the nation worth defending."
This session is very timely -- for NASA and EPA, too. In government, it seems that they're really pulling away from having scientists on the payroll (not as contractors) who do basic research that may not have an immediate practical use.
Sean Carroll, a Physicist at the University of Chicago, recently posted on why do we do science that isn't immediately practical (look back in his archives and you'll see more discussion of this).
Thursday, March 10, 2005
Thursday, February 17, 2005
Pretty cool. I'll get my first alert on Monday so then I'll know how cool. Too bad they're not RSS. I wonder, too, how they compare to e-mail alerts from the database vendors that have versions of the databases covered by this?
Wednesday, February 16, 2005
I was trying to figure out what search I would do that wouldn't provide any specific info from my place of work so disregard the subject...
Anyway, you can now get weekly search alerts/updates right in your aggregator. You have to be a subscriber ($$, of course). My e-mail alerts get to me on Fridays, so I'm guessing that's when the feed will be updated I'll come back and update this if not.
Tuesday, February 15, 2005
PACS: 68.35.Rh, 68.35.Bs, 68.37.Ef, 71.15.Nc|physics
Updated: wacky font sizes
Friday, February 11, 2005
This ambitious project seeks to solve a lot of what's wrong with mathematics information right now. Two (1, 2) new books came out in the last year trying to help users and librarians make some sort of in road into finding necessary math. While the books are very good the fragmentation and compartmentalization of the math knowledge is so severe that it's almost a lost battle.
Pitman, from Berkeley, has envisioned an open access set of survey journals and encyclopedias indexed by MSC (subject) and interlinked by author and collaboration graphs. Really quite a broad sweeping plan. Sounds like it could be done on a wiki (with editorial review). He hopes that the end information will be heavily cited (thus findable in WoS) and searchable on Google Scholar, MathSci, and Zentralblatt Math.
The first part of this is the probability and stochastic processes electronic journal: Probability Surveys.
Link this, if you will, to my suggestions (1, 2) of using established classification codes for new projects, etc. Note: Pitman doesn't propose a whole new classification scheme, he suggests the use of MSC. Perhaps mathematicians and statisticians should tag their posts and web pages with MSC codes? Maybe they already do?
Wednesday, February 09, 2005
This is a timely section. Everything from modeling to how age makes a difference in seeing traffic signs while involved in a conversation.
Also, RSS feed available for this and all other Extenza pubs.
updated (fixed a typo)
But here is the punchline: patterns of hallucinations reflect normal modes of the neurons in the visual cortex. By "normal modes" we mean the characteristic patterns of vibration, just as for a violin string or the head of a drum. The idea is that a drug such as LSD can alter the ground state of the visual cortex, so that it becomes excited even in the absence of stimuli. In particular, certain oscillating patterns can appear spontaneously. Generally these would take the form of different configurations of straight lines in the cortex itself; however, due to the distortion in the map from our visual field to the brain, these appear to us as spirals, tunnels, and so on. Indeed, Cowan and collaborators have shown that these normal modes can successfully account for all of the basic forms of hallucination classified by Kluever decades ago.Take time to read the comments, too. In the comments there's a comparison to other mathematical models of the brain which do not fit as well as these wave functions.
Tuesday, February 08, 2005
There I was, browsing the covers of our scientific journals when I ran across this article. Turns out that it's a new short story broken up in to parts accross multiple issues. Why do our issues come so late? I'm not saying it's particularly well written, but what a neat idea.
The article has quantum entanglement, negative refraction...
Wednesday, February 02, 2005
Here is a very brief list of things to do/read on WYoP:
- There's a set of blogs called Quantum Diaries that will be maintained by physicists and will describe a year in the life of selected particle physicists. Turns out that they're pretty much normal people. Go figure.
- IOP is calling it Einstein Year 2005. They have games, DJ remixes, and a poetry contest ( like Terry Pratchett's play on Andrew Marvell) on their site.
- Here are MSN , PubSub, Waypath, Blogdigger, Feedster feeds on the subject. I'm inaugurating a Technorati Tag