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Police Nation-Wide Use Wall-Penetrating Radars To Peer Into Homes

volvox_voxel chickenwire & radar cross section (290 comments)

I understand that chicken-wire has an extremely high radar cross section, as it's a regularly spaced array. I wonder how hard it is to see behind such a screen. Of course the attenuation varies by the spatial dimensions, A fun bit of calculation would be to find what the right size(s) of chicken-wire you need to block such instruments given their frequency ranges (assuming ISM band?). http://en.wikipedia.org/wiki/R...

I first read about how strong a return you get from chicken-wire from Stimson's book "Introduction to Airborne Radar" ..which is a pretty easy to read with a lot of colorful graphs, and is mostly targeted to fighter pilots, with blue boxes around the more complicated math for the more interested students. Most books ether have no math/calculus, or are geared toward graduate students. This particular one is a good mix between the two that gives you intuition when reading the graduate books..

about two weeks ago

Microsoft Ends Mainstream Support For Windows 7

volvox_voxel backwards compatability & development (640 comments)

I like the windows-7 interface, as well as the XP interface. My big problem however is backwards compatibility.I think we should be able to run programs from 50 years ago. I find it a real shame that it's often hard to get old programs/dev-tools/games/etc to work on a newer operating system. Sure, they have their reasons, but other operating systems have managed to handle this (especially ones that give you the source that you can recompile on a newer machine). Even when using "XP mode" I can run some old dev tools, but I can't run any 3D graphics because my nvidia graphics card only had drivers for windows-7 (on a 3 year old graphics card).

I'm friends with an FAE for a good embedded compiler company that was pretty frustrated trying to make their compiler work that was working fine under windows 7 work under windows 8. It took a long time for their developers to make the transition. I'm not sure what in the development process seems to be making development harder. I have developed for windows professionally, but not in some time. I'd love to hear from a developer perspective. I am currently working in the embedded linux/FPGA world.

Does the whole .NET framework lend itself to future compatibility as the code is compiled at run-time?

about two weeks ago

NASA Update Will Deal With Opportunity Flash Memory "Amnesia"

volvox_voxel Re:FRAM vs NAND (52 comments)

Using ww.findchips.com (a great site to check for parts and availability across multiple distrubuters) , in small quantities, the 2Mbit part is ~$5. But still, your argument is valid. For space born applications where reliability is everything, I'd still like to know about it's Rad-hard status.. These parts come in 8 pin packages, and could also likely scale if they wanted to. Who's to say that in the future that we wouldn't see orders of magnitude larger parts.

I personally am excited to see the memristor technology that can potentially eliminate both the ram and the hard disk, with 90ns access times and 1/100th the power consumption of flash. Perhaps this will blow everything else out of the water.


We'll see if HP labs can pull it off.

about three weeks ago

NASA Update Will Deal With Opportunity Flash Memory "Amnesia"

volvox_voxel FRAM vs NAND (52 comments)

I've never been a big fan of flash memory, given that it has a finite number of write cycles before a memory bit fails (varying between 1 and 100million write cycles). The probability may be low that an individual bit may need to flip so many times in it's lifetime, but it's still an issue.. A lot of care must be taken by the firmware engineer to handle this. There are a lot of job postings for firmware engineers that understand flash..

I'm a huge fan of FRAM. It has a lifecycle limit that is quoted at being 10 trillion write cycles (some mention at it being infinite). The memory density is lower, but is a lot more reliable. It's biggest issue is that the density is lower. For a spacecraft, I'd much rather have a board of these 2Mbit FRAMS then a large flash chip. They use these things in smart meters, etc. In embedded systems, you have to be really careful not to write to the flash too often out of risk of damaging the flash. Most fast SD cards have their own dedicated microcontroller (ARM9, etc) to do what they can to extend the life of the flash..

A datasheet of an FRAM device: http://www.fujitsu.com/downloa...

One question I have is how FRAM compares to NAND-flash in a harsh radiation environment, and what are the radiation differences on mars vs the earth. How many vendors offer rad-hard processes for FRAM, and how do they perform?

Here is one link I could find on FRAM, but the report from 2011 is not clear:


about three weeks ago

Box Office 2014: Moviegoing Hits Two-Decade Low

volvox_voxel something worthy of watching, a potential classic (400 comments)

I don't care for comic book recaps.. Give us characters that are believable, that tell something compelling abou the human condition; something that makes us think..Like "A Face in the Crowd" , "Night Of The Hunter" , "High Noon", "Bridge On The River Kwai", "A Dog Day Afternoon", "Who's Afraid of Virgina Wolf", "Bad Day at Blackrock", "Kramer vs Kramer", "Silkwood" .. There was a time when the public seemed to have a larger variety of movies to choose from.

Too much material seems to be regurgitated, and not enough screenwriters seem to read literature and science fiction . There are plenty of compelling stories that have never been told..

We are witnessing an extreme aversion to anything that is not tried and true, and it has cost them. The 70ies marked a time when movies were not so formulaic and deviated away from the old studio system. They took a risk, and it paid off with the Godfather, etc.

about a month ago

Ask Slashdot: Are Progressive Glasses a Mistake For Computer Users?

volvox_voxel multiple pairs of glasses suggestion (464 comments)

This is what I do. I am still relatively young, but I have an astigmatism (I need a cylindrical correction in both of my eyes, simple reading glasses don't work for me).. I have one set for normal use to see clearly at a distance, and another set that just corrects for the astigmatism for reading & computer use. This is much easier on my eyes for long coding sessions. I highly recommend getting the AR (anti-reflective) coating for both sets of glasses. Monitor glare is pretty noticeable otherwise.

Two sets of glasses keeps you from needing to compromise on your vision.

about a month ago

Research Highlights How AI Sees and How It Knows What It's Looking At

volvox_voxel Image processing; LIDAR; ADAS perspective (130 comments)

I've done some image processing work.. It seems to me that you can take the output of this Neural network and correlate it with some other image processing routines, like feature detection, feature meteorology, etc; A conditional probability based decision chain,etc.

I work on a LIDAR sensor meant for Anti-. I work at a start-up that makes 3D laser-radar vision sensors for robotics and autonomous vehicles /anti-collision avoidance. The other day, I learned that such sensors allow robots to augment their camera vision systems to have a better understanding of their environment. It turns out that it's still an unsolved problem for a computer vision systems to unambiguously recognize that it's looking at a bird or a cat, and can only give you probabilities.. A LIDAR sensor instantly gives you a depth measurement out to several hundred meters that you can correlate your images to . The computer can combine the color information, along with depth information to have a much better idea of what it's looking at. For an anti-collision avoidance system, it has to be certain what it's looking at, and that cameras alone aren't good enough. I find it pretty exciting to be working on something that is useful for AI (artificial intelligence) research. One guy I work with got his Ph.D using Microsoft's Kinect sensor, which is something that gives robots depth perception for close-up environments..

“In the 60s, Marvin Minsky (a well known AI researcher from MIT, whom Isaac Asimov considered one of the smartest people he ever met) assigned a couple of undergrads to spend the summer programming a computer to use a camera to identify objects in a scene. He figured they'd have the problem solved by the end of the summer. Half a century later, we're still working on it.”


about a month and a half ago

Apple Accused of Deleting Songs From iPods Without Users' Knowledge

volvox_voxel Time to switch players? (250 comments)

I just read that it's possible to transfer & play your I-tunes files on other devices, like an android phone. With an itunes player, I don't feel I own something if music files can be deleted without my permission. We have one of these players, but I've always been wary of it.

There are plenty of other players/dev boards that can read in music from something like a micro-SD card and play music without all the DRM hassles. There are plenty of open-source projects out there that use inexpensive boards, like the raspberry PI, or the STM32F4 board, running bare-metal, linux, or Free-RTOS..

about 2 months ago

New Atomic Clock Reaches the Boundaries of Timekeeping

volvox_voxel what's the up-time? (249 comments)

..This looks to be a pretty complicated beast that's built onto a table top and looks very much like a graduate research lab.. I wonder what the up time is?.. Mounts can drift with temperature, the bench does not look sealed, there is the potential for dust and contamination.. The laser power can fluctuate every so slightly and are probably run in optical-power mode.. The lasers can't be constantly up, etc. ..I used to work at a laser company that converted a bench-top tunable femtosecond laser with a lot of knobs that took a graduate student to run, and made it into an OEM product that was controller by a computer. It's hard to make commercial products out of some systems because it's hard to make it reliable (like femtosecond amplifiers).. I'm sure this thing requires a lot of babysitting. I wonder how long the measurement can stay stable?

about 3 months ago

Scientists Find Rats Aren't Smarter Than Mice, and That's Important

volvox_voxel Re:List of Animals by number of Neurons (154 comments)

The answer is yes, it does. The graph you showed us shows a linear trend line to fit the data.. This may have been entirely different in the time of the dinosaurs where the brains were apparently much smaller.

about 3 months ago

Scientists Find Rats Aren't Smarter Than Mice, and That's Important

volvox_voxel List of Animals by number of Neurons (154 comments)


The rat has an estimated 200E6 Neurons and 4.48E11 synapses, and the mouse has 71E6 neurons and ~1E11 synapses.

There is at least some correlation between intelligence and the number of neurons. A cursory search found this: -- Fact or Fiction: When It Comes to Intelligence, Does Brain Size Matte? http://www.scientificamerican....

It would be interesting to find more definitive articles that support or contrast this.

about 3 months ago

Experts Decry Randomized Ebola Treatment Trials As Unethical, Impractical

volvox_voxel Pediatric intensive care delema /cure (193 comments)

I have a friend that worked at the Stanford medical center's pediatric intensive care unit, where his patients were often flown in/helicoptered from all over the state. There are certain diseases that have a 100% mortality rate in children, where they could be fine two weeks before, and near death when he gets them. He developed a cure that saves about half the kids, and attributes most of the lost ones for not getting then to him fast enough. Everywhere else in the world they die. Stanford, being a research hospital, allowed him to experiment. He had a dilemma that bothered him immensely-- In order to gain wider acceptance, the medical community wanted to have a double blind test to see if the test, and show statistics.. When I last spoke with him, he was thinking about the minimum set of kids that would have to die and still be statistically acceptable. This was about 8 years ago, and don't know the current status. I'm not a doctor, and may have some of the details wrong. He did mention that his point of view was controversial, and it's hard for other doctors to reconcile that his patients lived though was was normally consider a death sentence.. He mentioned that he had to manage multiple organ failure trying to restore them to health. If a child was flown in fast enough, there was a good chance of a 100% recovery.

He had an interesting theory about the body and death (if I recall correctly) -- He believes that under some conditions, the autoimmune response goes out of control and starts actively trying to kill you. A lot of disease vectors and allergies can trigger this. . He said your body actively produces a lot of nasty toxins that cause multiple organ failures.. He did research on dialysis filters, and made sure to continuously purge the blood stream for the toxins. He would also follow up with chemotherapy to aid in autoimmune response suppression.. His method called for a very high volume of IV fluid which was pretty expensive. Stanford was willing to fit the bill. He believes that this method could be used to treat older patients as well.

Through a fog of memory, I'd like find out how this guy is doing. He's still doing pediatric critical care work, but moved on to Samaritan Hospital. He tells me that a lot of doctors he knows can't handle children dying in intensive care wards. He's an optimist and thinks about the number of children he's saved.. There are unsung heroes all around us.

about 4 months ago

Adobe Spies On Users' eBook Libraries

volvox_voxel plenty of alternatives to adobe (150 comments)

..Like Okular on Linux, etc. I'm not fond of any program contacting the mother-ship without my permission..

When I was in college, I remember being nervous about checking out books in the library. The librarian assured me that your lending habits are not part of the public record. At the time, I was working in a physical chemistry research lab, and the books in question were locked up in the cage out of a concern for explosives and public safety.

about 4 months ago

Complain About Comcast, Get Fired From Your Job

volvox_voxel Taping Conversations? (742 comments)

This incident sounds like a good case for recording all of your conversations with such companies. It is my understanding that you have to tell them that the conversation is being recorded; something they may not agree to. Does anyone here know more about the terms and conditions of this CYA method?

This example seems pretty hard to believe / outlandish but unreasonable and vindictive if true. It would be interesting to hear if there were similar stories from other people.

about 4 months ago

Researchers Working On Crystallizing Light

volvox_voxel Wynken, Blynken, and Nod .. (129 comments)

Crystal light? .. Reminds me of of the poem by Eugene Field. http://en.wikipedia.org/wiki/W...

Wynken, Blynken, and Nod one night Sailed off in a wooden shoe — Sailed on a river of crystal light, Into a sea of dew. "Where are you going, and what do you wish?" The old moon asked the three. "We have come to fish for the herring fish That live in this beautiful sea; Nets of silver and gold have we!" Said Wynken, Blynken, and Nod.

The old moon laughed and sang a song, As they rocked in the wooden shoe, And the wind that sped them all night long Ruffled the waves of dew. The little stars were the herring fish That lived in that beautiful sea — "Now cast your nets wherever you wish — Never afeard are we"; So cried the stars to the fishermen three: Wynken, Blynken, and Nod.

All night long their nets they threw To the stars in the twinkling foam — Then down from the skies came the wooden shoe, Bringing the fishermen home; 'Twas all so pretty a sail it seemed As if it could not be, And some folks thought 'twas a dream they'd dreamed Of sailing that beautiful sea — But I shall name you the fishermen three: Wynken, Blynken, and Nod.

Wynken and Blynken are two little eyes, And Nod is a little head, And the wooden shoe that sailed the skies Is a wee one's trundle-bed. So shut your eyes while mother sings Of wonderful sights that be, And you shall see the beautiful things As you rock in the misty sea, Where the old shoe rocked the fishermen three: Wynken, Blynken, and Nod.

Here is the Silly Symphony version: https://www.youtube.com/watch?...

about 5 months ago

Researchers Working On Crystallizing Light

volvox_voxel Discworld (129 comments)

This sound like something out of one of Terry Pratchett's Discworld novels..

about 5 months ago

To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars

volvox_voxel container ships and bulk transport -- (491 comments)

I understand that these are major polluters.. I've seen pictures in a Britannica "Science and the future" book of bulk transport ships using large servo driven metal sails. I wonder to what extent this technology has been explored. When doing a google search, I found this http://www.cnet.com/news/cargo... ..But it doesn't look like it was actually built.

I've heard anecdotal evidence that a transport ship is equivalent to 50,000 cars.. And this site http://www.viewzone.com/sixtee... claims that it's much higher. I'd be interested in in a reliable source for this. I understand that they use different fuel depending on how close they are to a human settlement, and the cheap stuff is a really big polluter. It's a solid a room temperature and has to be heated up to flow into the engine. At the very least, I'd like to see electrostatic percipitators on the smoke-stacks.

We once had world trade based on sail. Much/ most of that cargo does not need to get to it's destination quickly..

about 5 months ago

Intel's Haswell-E Desktop CPU Debuts With Eight Cores, DDR4 Memory

volvox_voxel Re:*drool* -- FPGA development (181 comments)

I do a lot of FPGA programming and It takes me 15-20 minutes to synthesize a design on a modern fast computer. As more of the part is being used, synthesis takes more and more time, as the chip becomes harder to rout.. I'm a user that is primarily CPU bound. I hope that Intel will continue to push on the raw performance. For the past few years, as we've only seen marginal improvements in CPU performance.

There is also the issue that FPGAs keep getting cheaper/bigger, so no matter how fast your rig, it always takes a long time to synthesize. I'd be curious about what other FPGA developers use to boot performance.. Overclocking/water cooling does seem to help, as does using faster ram.

about 5 months ago



Harvard Student Charged For Anonymously Emailing Bomb Threat To Avoid Final

volvox_voxel volvox_voxel writes  |  about a year ago

volvox_voxel (2752469) writes "A 20-year-old Harvard student who was allegedly trying to dodge a final exam has been charged in Monday's bomb hoax that led to four buildings being evacuated and several final exams being canceled, CBS in Boston reports. .. Kim tried to conceal his identity using one service that assigns people anonymous IP addresses and another that creates an anonymous and temporary email account, according to the federal complaint."
Link to Original Source


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