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Gamma Ray Mystery Reestablished By Fermi Telescope 95

eldavojohn writes "New observations from NASA's Fermi Gamma-ray Space Telescope reveal that our assumptions about the 'fog' of gamma rays in our universe are not entirely explained by black hole-powered jets emanating from active galaxies — as we previously hypothesized. For now, the researchers are representing the source of unaccounted gamma rays with a dragon (as in 'here be') symbol. A researcher explained that they are certain about this, given Fermi's observations: 'Active galaxies can explain less than 30 percent of the extragalactic gamma-ray background Fermi sees. That leaves a lot of room for scientific discovery as we puzzle out what else may be responsible.' And so we reopen the chapter on background gamma-rays in the science textbooks and hope this eventually sheds even more light on other mysteries of space — like star formation and dark matter."
Data Storage

"Limited Edition" SSD Has Fastest Storage Speed 122

Vigile writes "The idea of having a 'Limited Edition' solid state drive might seem counter-intuitive, but regardless of the naming, the new OCZ Vertex LE is based on the new Sandforce SSD controller that promises significant increases in performance, along with improved ability to detect and correct errors in the data stored in flash. While the initial Sandforce drive was called the 'Vertex 2 Pro' and included a super-capacitor for data integrity, the Vertex LE drops that feature to improve cost efficiency. In PC Perspectives's performance tests, the drive was able to best the Intel X25-M line in file creation and copying duties, had minimal fragmentation or slow-down effects, and was very competitive in IOs per second as well. It seems that current SSD manufacturers are all targeting Intel and the new Sandforce controller is likely the first to be up to the challenge."

Comment Partial answer (Score 1) 684

I would think that you would find a better discusion on the mobiread forum, since this is a forum for serious ebook readers. Personally, I would never call a backlit screen useful for serious reading. It doesn't work well in brightly lighted areas (such as outdoors), and the flicker causes eyestrain and fatigue. Reflective technologies such as eInk can be read for hours (like a book). Touch screens do reduce the contrast ratio for these type of screens.


Moscow Police Watch Pre-Recorded Scenes On Surveillance Cams 114

An anonymous reader writes "During several months of 2009, Moscow police looked at fake pictures displayed on their monitors instead of what was supposed to be video from the city surveillance cams. The subcontractor providing the cams was paid on the basis of 'the number of working cams,' so he delivered pre-cooked pictures stored on his servers. The camera company CEO has been arrested."

Comment 30 Fps myth (Score 2, Interesting) 521

There were a lot of studies done a long time ago, and there are some very accurate psycho-visual computer models of the human visual system. I had the pleasure of working with the Jeff Lubin model when I worked at Sarnoff Corp, which won an Emmy Award back in 2000.

The 30 fps requirement is not a fixed point, but depends upon a lot of other factors, including viewing distance, field of view, and lighting conditions. The reason that film operates at 24 fps is because it is expected to be viewed in a darkened room. When film is trans-coded for TVs, they have to modify the gamma for a normally lighted viewing area or it will look bad. NTSC TVs are interlaced, displaying 60 fields per second, even though the frame rate is 30 frames per second.

Bottom line is that this article should include the environmental factors under which this point was made.

Comment Re:Brings back memories (Score 1) 249

Which reminds me...

The RCA 1800 family had an interesting feature... Every instruction took 8 clock cycles (with a few extended ones that took 12). This means that it was easy to, not only figure out how long a routine would take to run, but write routines to take up a specified time.

In the RCA VIP (hobby) computer, the tape output was a frequency-shift keyed output that was driven by a software UART created by this technique. You could also program it to play music producing the appropriate frequency using a software timing loop. I wrote a few programs that did just the opposite... did frequency decomposition using the built-in zero-crossing detector for the tape interface (a poor man's spectrum analyzer).

It was pretty amazing what could be done it 8k bytes of memory. :)

Comment Re:Acoustic coupler era and POTS! (Score 2, Interesting) 249

I developed a 300 baud modem for the (then) brand new RCA data terminal back around 1980. The trickiest part of this thing was that the filters had to be designed and made from discrete components.

The plant manager saw my design which had precision components and he had a fit. His instructions were, "Use the components we have in the stock room". He also saw the line transformer and he said, "This is the age of semiconductors, get rid of that transformer".

I spent weeks researching how to replace that transformer with a semiconductor device that wouldn't distort the signal, operate bilaterally (in and out), and withstand the the 10,000 volt pulse that the FCC required for testing. I finally found such a beast, so I gave the manager a choice... Use the 6 cent transformer, or replace it with a $40 semiconductor.

My complaints about using non-precision components fell on deaf ears, so I figured the only way to prove that this wouldn't work would be to build a prototype and show that it would fail. To my dismay the first prototype worked flawlessly. I was told to build 10 more for FCC testing but not a single one of these worked even though the frequency response curves were all on the mark. I finally discovered that the phase response was a mess. I finally convinced them to use precision components.

Comment Re:Why oh why not OpenSolaris? (Score 2, Informative) 206

I don't work for Sun either, but I agree with many of your points. My homebrew NAS server has been running OpenSolaris since build 49 and ZFS has uncovered issues like a flaky sata cable, and an unstable power supply without losing a single bit of data. In some other systems with similar problems, I found silently corrupted data on drives with ntfs, xfs, and hfs+. I would not go to a non-zfs flle system without some kicking and screaming.

I don't know if OpenSolaris, EON, or NextentaOS is missing any of the features of FreeNAS, but I would think about these as a viable replacement. One advantage is that they will always have the bleeding edge zfs enhancements first, like the new deduplication feature.

Comment Zfs or nothing (Score 1) 206

Zfs has saved my data enough times to warrant it as an essential part of any NAS system I use and value it's contents. I'm seriously looking at the OpenSolaris based NextentaOS and EON as the only remaining choice for an open source NAS solution. I'm also using Zfs on my Mac OS/X machines after I silently lost data on both NTFS, and HFS+ drives and await the community effort to bring zfs on mac up to the latest codebase.

Comment Re:You're accidentally correct (Score 1) 849

I've been an audiophile/engineer for a long time. In my world, there are a few "golden" ears I've met that hit things absolutely on the nose every time. They can tell the level of dynamic compression, frequency shaping, etc. One particular one is a sought-after final mix-down recording engineer. Calling audiophiles names serves no purpose other than showing you're out of the scene.

CDs are notoriously flawed. Remember that it was trying to fit a particular classical piece on a CD that caused the trade-off that came up with an 8-bit sample and a 44.1k/sec sample rate. Both of these noticeably degrade the sound. In vinyl there was a problem with SNR and tracking that caused the RIAA phono equalization. Bottom line is that both vinyl and CDs have their own colorization to deal with. Personally, I find the vinyl sound more pleasing (note I didn't say better) which has a longer serious listening period before I get fatigued (tired of listening).

You can always tell the true audiophiles because they are skeptical about the hype that comes down the pipe (remember "Holographic sound processors?). They do true engineering/subjective testing in a controlled environment to see what is real or not. The high-end audio cable is such a point. As an engineer, it was obvious that the only difference in wires are their impedance, resistance, and capacitance values. Since they are combined to produce any frequency coloration, dropping the resistance low enough will preclude reasonable values of the others from affecting the sound (within hearing range). A blind A-B test of various wires showed that any wire 14-gauge or higher was indistinguishable in my setup. Guess what I use for speaker wire... The fat zip-cord that is used for outdoor low-voltage lighting. I got it at 8 cents/foot.

The same argument goes for transistor vs. tube amplifiers. You can make a transistor amp sound exactly like a tube amplifier with a single-ended instead of a totem-pole design, and they stay in the optimum operation region a lot longer (75 years) than it's tube counterpart (6 months). Check out single-ended DIY amplifier designs at the PassLabs web site.

Bottom line, Anyone can tell the difference between lossy and non-lossy compressed audio once the loss gets big enough. What is big enough depends upon a lot of factors. In this case, I have a real problem with the equipment and choice of subjects. We like what we're familiar with, not necessarily what is better. After driving the same car for years and then moving to a different model, it usually takes some time to get adjusted to the sound system until it feels comfortable just because it's different.

The main places where coloration occurs is in the conversion of sound . That's why I built my own hybrid transmission-line/electrostatic loudspeakers. No one that has heard them has not made a comment that they heard things in familiar pieces that they didn't even know existed (a flute in the background, etc.). This is true with vinyl or CD as a source.


Comment Re:ZFS is overhyped and not a good fit for desktop (Score 1) 329

On most systems that support ZFS, there is already the capability to to encryption via the loop back interface. They are working on zfs native encryption and it has been under test internal in Sun for awhile. De-dup capabilities will be available soon. The development of zfs has been incredibly fast for a file system. Considering the Mac implementation is at rev 8 and I've got 14 on my OpenSolaris system should say something... Apple hasn't really put much effort into keeping up with the state-of-the-art of ZFS.

I've never had corruption issues on ZFS over the several years of heavy use, ups crashes, lightning strikes, etc. During the same time, I've seen several XFS, NTFS, and HFS+ filesystems in adjacent servers get twisted beyond repair.

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