Channels ▼


Keeping the Lines of Communication Open

When working on the article "Wireless Security—Probably" for the Dr. Dobb's Report newsletter, I learned that wireless sensor networks—those networks of devices that monitor everything from earthquakes to secure military operations—are susceptible to attack by intruders. However, a trio of computer scientists has come up with a "Probabilistic Voting-based Filtering Scheme" to ward off intrusions. Reading this report led David Mulchy to forward a note gleaned from

"On April 5, 1975, two cosmonauts were dumped onto the Altai Mountains in the world's first manned space launch abort. Pilot Vasily Lazarev and flight engineer Oleg Makarov survived a harrowing 20 G descent and then a bouncing ride down a mountainside before their spacecraft came to a safe stop. They came as close to dying as anyone can and later talk about it."

Jim Oberg's book Red Star in Orbit goes into further detail. After the separation failed the spacecraft was spinning at 30 rpm. The ground controllers thought everything was normal because the ground control software was programmed not to display the data if the data was unreasonable. Sometimes sensors tell the truth even when their outputs seem unreasonable.

Likewise, "Multicore Goes to the Movies" described DreamWorks Animation's plan to release all of its movies in 3D, thanks to Intel multicore processors and parallelization tools. Which prompted Jim Gyer to send this explanation of 3D glasses:

The red/blue glasses were for B&W movies. There were a few color 3D movies. That was late '50s. At least the ones I saw used a polarized light scheme with "grayish" glasses, so that's not wildly new. To my young eyes, it seemed that one projector showed what was simply a 2D color version of the movie through a polarized filter. That's what was distributed to theaters that didn't want the extra grief of 3D, drive-ins, and later TV. The second projector showed (at least what appeared to be) a "thin" B&W version of the movie through a different filter. It was really very dark gray and slightly lighter gray (little light to wash out the color image). If you looked at the screen without glasses, you saw a normal color image with a very pale "ghost" image. It may have had some very washed out color but I think it was pure B&W. The rest of the "deception" was supplied by the brain.

Speaking of multicore, Chris Boes wanted to remind me about National Instrument's LabVIEW (and no, he isn't an NI employee):

Have you ever looked at National Instrument's LabVIEW? LabVIEW is a graphical, data-flow programming language that is designed for engineers and scientists. By design, LabVIEW is also a highly parallelized programming language for the creation of threads for code that must execute simultaneously. Because of this design, National Instruments has been able to adapt the language to take advantage of multi-core processors. A developer can create threads and assign them cores and priorities to optimize code and resources.

Then around Labor Day, I acknowledged in "Happy Birthday Packet Switching, or Laboring on Labor Day" Leonard Kleinrock getting a National Medal of Science for his pioneering work with packet switching and network connections on Labor Day nearly 40 years ago. Harlan Cohen pointed out that I failed to mention some important trivia: What was the first message to be sent over the Internet (ARPANET)? Says Harlan:

The message itself was simply the word "login." The "l" and the "o" transmitted without problem but then the system crashed. Hence, the first message on the ARPANET was "lo".

Coincidence being what it is, "Turning PCs into Digital Radio Transmitters" described a project called Gram-Vaani ("voice-of-the-village"), which connects rural radio stations in India to the Internet via software and computer-based FM transmitters, cutting station startup costs from an estimated $50,000 to $2,500. Bob Cummings reported he kicked off a similar project:

I just launched WWTF radio last weekend. Where I live, there isn't an option for broadband except satellite. And that is wicked expensive. And the rural community will not support a very eclectic radio station. So with a card from I launched WWTF. Right now, I can only broadcast about a quarter mile. I just run a jumper cable from the sound card to the PCIMAX2700+ card, start up the supplied software to dial into a non-used frequency, and I am on the air (currently at 88.1 on your FM dial). Running on my old file/back-up server (1.2 Athalon with about 1.5 gig of RAM) just fine. Total investment of less than $200.

There you have it folks. Keep those e-cards and e-letters coming, and those lines of communication open.

Jonathan Erickson


Related Reading

More Insights

Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Dr. Dobb's encourages readers to engage in spirited, healthy debate, including taking us to task. However, Dr. Dobb's moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing or spam. Dr. Dobb's further reserves the right to disable the profile of any commenter participating in said activities.

Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.