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User: harrkev

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  1. Re:No surprise there... on Amateurs Beat Space Agencies To Titan Pictures · · Score: 3, Interesting

    NASA could not endorse such a project.

    Is that life??? Nope. Just a JPEG artifact.

    And don't forget that some people are VERY skilled with photoshop.

    People should have access to this data, no doubt about it. But anything done by an amateur should be taken with a grain of salt. I am not saying that amateurs can't do great work. But take any amateur data as being just a pretty picture to satisfy your curiosity. If you are a scientist, then don't stake your career on an amateur photo.

    On the other hand, I COULD see some value to amateurs providing scripts. Some sort of automated process that could grab the raw picture directly from the NASA or ESA servers, and processing it using pre-defined rules. This would have the advantage of:
    1) You know that no photoshopping is going on.
    2) You know exactly what they are doing, and can modify thier process.
    I COULD see something like this being useful to NASA and ESA.

    Does anybody know of programs that could handle image manipulation according to a script? Imagemagik might be able to do some of this, but if I were doing this, I would want something that could also handle 2-D FFT and DCT conversions, and run complex scripts to work with the data as a matrix. Matlab would be perfect if it wasn't so expensive (and hard to find at home).

  2. I would imagine... on Closed Digital Cameras - Does Anyone Care? · · Score: 5, Insightful

    I would imagine because nobody cares...

    If you are starting from scratch, there is a lot to screw up. First of all, you need to get the metering right, which is far from trivial. You also need to be able to auto-focus, which is also far from trivial. And this is AFTER you figure out the interface to the CCD, LCD, and buttons. Plus, you have to know how to control the zoom motor, auto-focus motor, and flash.

    If you DID re-invent the wheel (and did a good job of it), what do you gain at the end? Sure, you might be able to improve metering a little. You might be able to improve the user interface. But if a camera has a raw file format, you are already getting all of the quality that the hardware can deliver. And JPEG already has pretty good compression, so it is hard to improve on that.

    I saved the best part for last. You go through all of this work on a 5MP camera, which is discontinued after one year and replaced by a 7MP model with a different architecture. So, you decide to upgrade, and throw all of your work in the trash.

    If you want to, feel free. But include me out.

  3. Re:Threads vs. Processes on BigTux Shows Linux Scales To 64-Way · · Score: 1
    IBM worked on their own threading implementation for linux (NGPT) that was 2 times the speed of LinuxThreads.
    So why hasn't this been rolled back into the official kernel? Does it totally suck for uni-processor systems?

    So far, it seems that IBM has been willing to share their candy with OSS people.
  4. Re:Pardon my ignorance, but... on BigTux Shows Linux Scales To 64-Way · · Score: 1

    Computer science people have a name for everything. Some tasks are easily parallelizable, and others are not.

    There is something called "Amdahl's Law" which is all about this topic. Basicly, you can predict the percent speedup based on how parallelizable the task itself is. This law, of course, assumes that the OS and multitasking is completely overhead-free, so it is sort of an upper bound on how fast something can go. But it is still interesting.

    THIS is simply the first result form a google of "Amdahl Law".

  5. Re:A router routes packets. on Linux Getting Harder To Crack · · Score: 1

    It is clear that you do not know now NAT works.

    Every NAT box has a table. Each entry in the table has the following data:

    1) Source IP address (usually 192.168.?.?)
    2) Source port (usually over 32K)
    3) Destination IP address (could be anything)
    4) Destination port (usually 80 for web access).
    5) Re-numbered source port (some routers have this, some don't - we will assume that ours doesn't, just to simplify things).

    My computer, 192.168.1.69 port 40,000 (random port) sends a request to 1.2.3.4 port 80 (http request).

    The NAT box takes the packet, removes 192.168.1.69 and replaces it with the ISP-assigned IP address (let's assume 9.8.7.6). It also fills in an entry in the table.

    1.2.3.4 port 80 gets the data and returns the web page to 9.8.7.6 port 40,000.

    NAT gets data from 1.2.3.4, port 80. It is addressed to 9.8.7.6 port 40,000. That matches an entry in the table, so the 9.8.7.6 is replaced with 192.168.1.69, and sent to the LAN.

    My computer gets what it wants, and is happy.

    Mr Joe Cracker sends ANY sort of traffic to 9.8.7.6. This can be either a portscan, or a deliberate cracking attempt. My NAT box gets it. Mr Cracer's source IP address is not in the table. Packet dropped. In order for Mr. Cracker to get ANY traffic in, he must spoof his address as being from 1.2.3.4, AND know the destination port on my PC. In short, the only way that Mr. Cracker can send ANYTHING to my PC is to snoop on my conversation to 1.2.3.4. So, people who can sniff passing traffic might stand a shot of getting something in., but he could only do this by inserting data into an existing stream. But Mr. Cracker could NOT attack an arbitrary port, such as what you would need for worms.

    The table is the key for NAT. If you have two computers sharing one IP address, and both go to google for a query, how does the NAT know which computer gets which response? The answer is that the outgoing port numbers are randomized. So it is a combination of source port and destination port and IP address that determines where the packet goes. If a packet comes in that does not match, the NAT does not have any idea which computer gets is. So it is dropped.

    This is useful.

    And as to my comment that you questioned, it is simply that you would find it difficult to find an ISP over here that would give you a block of IP addresses for free. You get one address included. More addresses = more money.

  6. Re:A router routes packets. on Linux Getting Harder To Crack · · Score: 1
    Let's assume that the script kiddie in question is across the country. They send a packet to 192.168.0.1. How does this get to me? Answer: it wouldn't. This is a non-issue. You cannot route this packet, as the address does not go anywhere.

    The ONLY chance would be if the particular script kiddie was in my neighborhood. Then, what you say may be true. But in this case, my NET box has blocked 99.99% of all script kiddies. Good enough. I also run a software firewall.

    And a NAT box IS based on a connection. Look up how it works. I open a page at slashdot.org. The NAT box stores my real IP address (and port number) in a table along with the slashdot IP address (and port number). When traffic comes in, the only thing that will be allowed through is traffic from slashdot.org, coming from the right port, going to the right port. Simple. If a packet does not match the data in the table, it is blocked. So the only way for ANYTHING to get through is if MY PC initiates it.

    I would never use an ISP that took this kind of attitude
    Then we would not be having this discussion, except maybe by snail-mail. You simply would not be likely to have a broadband connection.
  7. Re:A router routes packets. on Linux Getting Harder To Crack · · Score: 1
    NAT was designed to aleviate the IP address space shortage, period. There is no reliable security in doing NAT - you're relying on your ISP's routers to "do the right thing". If you want that kind of security you need a connection tracking firewall.


    Ummmmm. Some random script kiddie at some random IP address sends a packet my way. My NAT box ignores the packet, and my PC never even sees it. I find some value in this. This is not 100% security, but it sure helps. Traffic cannot find its way in unless my PC first opens a port to that specific IP.

    Please explain how this is not useful.

    Also, I would rather doubt that ISPs in America will start handing out blocks of addresses without wanting some money. At one time, my cable modem provider wanted $10 per month for an additional IP. v6 will make them more plentiful, but why would they want to turn down a free revenue stream? I admit that I could be wrong, but I am used to being charged for everything, especially with cable providers:
    As a service to our customers, we are adding new channels. The Lithuanian news channel, the 'watching paint dry' channel, and the 'swahili lesson' channel. Your monthly bill will only increase by $10 for these exciting new channels.
  8. Re:A router routes packets. on Linux Getting Harder To Crack · · Score: 1
    The *only* reason for using NAT/PAT is to relieve the IP address shortage. Under IPv6 this will nolonger be needed so it is far more sensible to give every machine a real address and control access with a firewall.

    Almost, but not quite. For home users, NAT will always have a place, as long as ISPs only include one IP address, and want to charge $$$ for a second or third IP.

    This was the rationale behind the first NAT boxen, with the firewall being a happy side-effect.

    What you say is true for business users who get a block of addresses, though.
  9. Re:A router routes packets. on Linux Getting Harder To Crack · · Score: 1

    NAT is secure, for what it does. It stops EVERYTHING on the outside from getting in (assuming that it is configured properly). The ONLY WAY for traffic to get in is for you to request it. NAT = firewall without application control.

    So it does not protect against stupid users and/or browsers. It will not stop spyware. But it will stop a random script kiddie or a worm.

    So they are not the end-all and be-all of security. But they are useful. You can install XP and then fetch the drivers and patches that you need unmolested (as long as you only browse trusted sites, like Windows Update, nVidia, etc.)

    I also use a software firewall. I would not feel safe without one. But there may also be flaws in my firewall software (it has happened). And every packet that is denied at the NAT box is one less packet that has to waste CPU cycles in the software firewall.

  10. Re:Doesn't run Windows on IBM Pledges To Make Xen More Secure · · Score: 1
    No doubt that Xen will perform better for any OS that supports it and it will be a great next generation virtualization platform.
    <sarcasm>
    I can just see Microsoft jumping though hoops in order to get XP (or LongHorn) to work with this.
    </sarcasm>
  11. Re:Here's one on Spam and Spyware Too Much for Some Users · · Score: 2, Interesting

    Firefox would help, but is not completely foolproof. There are still exploits for Firefox, and this would not help with downloadable stuff.

    Perhaps the best solution for those people who just don't (or can't) learn to protect themselves is to hand them Knoppix.

    Pull the plug on the network while in Windows. If you want to surf then insert Knoppix, reboot, and plug the cable back in. Safe, secure browsing. And if you DO get compromised, security is one reboot away. This still does not stop Spam, though. And with Knoppix, web-based e-mail is probably the easiest.

  12. Re:Not even worth discussion. on Bundled Applications for GNU/Linux? · · Score: 1

    2) Users don't give a crap about this, as long as their applications run. 95% of users don't know how much disk space an application takes up.

    3) Again, users don't give a crap about this. 95% of users can't even tell you how much memory an appliaction is using, or how to find that out.

    Most users don't know how to check memory usage and/or disk usage.

    But most users DO notice when the hard drive starts making noise and the system slows down (paging).

    And most users DO notice when they have to go deleting stuff to make room on their hard drive.
  13. Re:Dupes in system...=space tradeoff on Bundled Applications for GNU/Linux? · · Score: 1

    The solution is the path is easy.

    Have one directory called "links" or something like that. Each application can create a symbolic link to the main executables in that directory. Then, other than the obvious links to /usr/bin and the like, you just have "links" in your path.

    On my sun workstation, one tools tell me "absurdly long path truncated" or something like that. But I have to keep the path long in order to get access to all of the tools that I use on a daily basis. Nice.

  14. Re:Dupes in system...=space tradeoff on Bundled Applications for GNU/Linux? · · Score: 1

    Linux already HAS one file for each application.

    CSH is one file.
    BASH is one file.
    LS is one.
    MKDIR is one file.

    I am not sure what the complaining is about!

  15. Re:What happened... on Smart Guns are Coming · · Score: 5, Insightful
    I think that legislation for waiting periods and against concealed-carry is a great idea

    Good idea. Criminalize carrying a gun. That will stop the criminals -- they always obey the law. If this actually works, I say that we pass a law requiring all criminals to report to their nearest police station for arrest. That will clean up the streets.

    People who fill out the paperwork for a conceled permit, take the manditory safely training course, pay the rather large fee, and get fingerprinted (I have been through this process) are the ones most likely to obey the law. A criminal will NOT go through all of this trouble, and a criminal would not be stopped by a law criminalizing concealed carry.
  16. Re:What happens when... on Smart Guns are Coming · · Score: 3, Interesting

    Worse than that. What if a cop has been assaulted and his hands are covered in blood -- or the sensors are caked in blood and mud after a scuffle in a dirty alleyway?

    Does this thing need to have batteries replaced every year? What is the false positive vs. the false negative rate?

    Really, this is just an electronic replacement for common sense - and not a very good one at that. Bad idea. I would not buy one.

  17. Re:Now with Lens Flare! on Leapfrog Talking Pen · · Score: 3, Informative

    They can make it. This is nothing more than a Logitech io Pen that has a new case, speaker, and software.

  18. Re:Fractal image format on Breakthrough In JPEG Compression · · Score: 4, Informative

    It certainly seems possible, except for patent issues.

    The heart of JPG is the DCT transform, performed on an 8x8 block basis. This is not being changed, since they claim that the original JPG can be reconstructed bit-for-bit exact. Hence their algorithm must be "lossless." Othewise, if you apply lossy compression to lossy compression, you get even more loss.

    Here is the JPEG algorithm in a nutshell...
    1) Convert RGB into Brightness, Color, and Saturation (three separate monochrome images).
    2) Down-sample the Color and Saturation images. (This reduces the image size by 1/2; VERY lossy but you don't notice it)
    3) Break each image into 8x8 blocks.
    4) Perform a 2D DCT (discrete cosine transform) on each 8x8 block separately.
    5) Quantize the DCT data using the special JPEG quantizaion matrix (this is where most of the loss happens)
    6) Convert each 8x8 block of DCT data into a 64-number stream using the zig-zag scan (this just shuffles the order of the data, nothing more).
    7) Apply a specialiazed huffman code to compress the data (lossless compression).
    8) Write the header information, and dump encoded data to the file

    I could be waaaay off-base on this, but I suspect that they have found a better replacement for the zig-zag scan and huffman coding steps. Optimizing another step would still be lossy, and could not re-create the original JPEG byte-for-byte.

    But I must admit that I am completely baffled how they could take a huffman code optimized for JPEG and find something 30% better. Such a thing seems to be impossible, given what I know of coding theory (which, I admit, is a but rusty).

  19. Re:In this case... on Will Microsoft Control the Anti-Spyware Market? · · Score: 1

    Firefox is NOT a good example. The main reason that Firefox is better is because M$ has done NOTHING to their browser in the past few years.

    When M$ kicks things into high gear, they can add a lot of nice features to a product in a short period of time (meanwhile ignoring security and standards). Browsers are not somthing that they show an interest in right now (but that may change again if IE looses too much share). Spyware IS something that they are obviously interested in. Therefore, they should be able to do a good enough job to monopolize this market. Then, in a few years, they will move on to other things. Either this new tool will generate a constant revenue stream and be supported, or it will be ignored, allowing for competition again.

  20. Re:Not hard to control the anti-spyware market on Will Microsoft Control the Anti-Spyware Market? · · Score: 1

    Look at this as an opportunity.

    M$ has been tooting their own horn about lower TCO (and completely ignoring the facts). Now, if there is a subscription fee thrown in for this new anti-spyware tool, that drives up the TCO -> good for Linux.

    Of course, I am sure that M$ will skew the numbers so that they still have a lower TCO ("Linux causes your server to catch on fire, so you will need a new $2000 server every week -- Microsoft wins"). But this will make it harder.

  21. Re:It's those idiot greens again on The Tin-Whisker Menace · · Score: 2, Insightful

    Have you ever seen inside a typical chip? The die is bonded to a ceramic carrier, and wires are then bonded to the chip. And those wires are also "pretty damn this." So, thickness is not really an issue here. If a whisker can handle 1mA, that is enough to screw up a signal line.

    And for what it's worth, I have a MSEE and design digital electronics for a living.

  22. Re:Wow, is this for real on MS AntiSpyware vs Ad-Aware vs. SpyBot · · Score: 3, Funny

    They have only owned it for a few weeks. Even Microsoft has limits on how fast they can screw stuff up.

  23. Re:Someday on What Do You Believe Even If You Can't Prove It? · · Score: 1

    Well, there are the writings of Cornelius Tacitus (55-120AD), a Roman historian who mentionsed that Jesus started a religious movement and was killed by Pilate.

    Oh, and there is Lucian of Samosata, a writer of Greek satire (2nd century). He was definately NOT friendly to Christians, but even he confirms that Jesus lived and was crucified.

    And how about Suetonius, another historian. He said that Christians were in Rome by 64AD.

    There are others (Thallus, Phlegon, Pliny the Younger, etc.). But this is enough of a sample.

    Should I mention the ancient Jewish texts, also? The Jews were VERY unfriendly to Christians, but even ancient Jewish texts admit the Jesus lived and dies on a cross.

    Also, the earliest of the four "Gospels" appeared around 70AD -- still in the lifetime of witnesses (Jesus died around 30 or 32AD). So, if there were some incredible inaccuracies, the critics would have loved to parade around witnesses and say "Here is a person who was there, and it did not happen like that!" No record of such criticisms are recorded. A *LOT* of people did not like Jesus, but NOBODY at the time could even hope to claim that he did not live.

    Please learn the difference between facts and rumor/slander.

  24. Luchbox... on External PCI Box for Laptops? · · Score: 2, Informative

    You might also want to consider a lunchbox PC. These generally have a few PCI slots built-in. They are also likely to be smaller than having a separate laptop and PCI box. And this IS a comodity item (more or less). Even though the market for these is small, it is larger than a separate PCI box. This should keep the price down.

    Here are some random sites which were the first hits off of Google using "Lunchbox Computer":

    http://www.lunchboxcomputers.com/
    http://www.th eportablepc.com/portable.htm
    http://www.stealthco mputer.com/portables.htm

  25. Re:HAM Geeks on Ham Operator Sets New Miles-Per-Watt World Record · · Score: 2, Informative

    Actually, this IS kind of neat. Most of the ham market is owned by Japanese radios: Icom, Yaesu, and Kenwood. It IS neat using American gear.

    Plus, the Elecraft K1 is a kit. If you want one, you get a board, a metal box, and a bag full of parts. Some assembly required. For some people (like me), this is a feature, not a bug.