This may be obvious, but:
1. Don't network this computer.
2. Implement physical access controls.
3. Require strong passwords.
4. Isolate this computer from all other electronic and RF sources to comply with TEMPEST requirements.
5. Don't ask these sorts of questions on Slashdot. You have already compromised OPSEC.
'Spray,' shown above, is an underwater glider developed under ONR support by Scripps and Woods Hole scientists (Sherman et al., 2001) to provide a small long-range autonomous platform for long-term ocean measurements. 'Spray' uses primary-lithium-battery power and a hydraulic pump to periodically change its volume to alternately glide upwards and downwards. This results in a see-saw path at descent/ascent angles of 18-25 degrees and forward speeds of 25-35 cm/s. Heading and ascent/descent rate are controlled without control surfaces by moving weight (battery packs) inside the hull to change roll and pitch, much as a hang glider is controlled. As shown below, at the surface Spray rolls 90o to raise one of its wings, each of which contains a combined GPS/Iridium antenna. Using the wings to house antennas eliminates the drag associated with separate antenna housings and allows redundant systems so that communication and navigation can continue even if one antenna is damaged, as happened when one Spray was run over by a surface vessel...
iPod compatible? Sounds like Real Networks to me. But I still don't know how they will get the music into your iPod catalog w/o iTunes integration, which Apple is unlikely to give up...
What about the Iomega micro-mini? The Iomega web site says that it is USB 2, and it is really small, which I like. The rotating cap is cool too. Needs a write-protect switch, though...
Chipcon actually has a ZigBee compliant chip already...it's the first I have seen. Of course, they claim is the the wrold's first one too.
Since 2.4 GHz is an ISM band, there are no license requirements, and there are already many proprietery transceivers on the market. The difference here is that Zigbee (802.15.4) is an IEEE std. ZigBee was developed because many felt Bluetooth was too complicated for sensor network and automation type applications. Indeed, with the Piconet scheme of 7 active nodes, large Bluetooth networks are very complicated, and I don't think the problems associated with large meshes of piconets have been solved. ZigBee is supposed to be lower power, and it uses a more robust DSSS transceiver. It also implements some additional security protocols. However, the data rate is at best 4x slower. Bluetooth has applications in one market segment, namely personal computing, and ZigBee in another (sensors, automation).
There is room for each protocol in the appropriate vertical marketplace, and no one protocol is appropriate for everything. Think of 802.11a/b/g, Bluetooth, and ZigBee as FireWire, USB, and... serial.
"Enter 802.15.3, a specification being groomed for IEEE standard status that provides ad hoc wireless PANs - short range (1-50m) and ad hoc, in other words. 802.15.3 builds on the 802.15 standard by adding QoS specifically to allow the PAN to carry digital imaging and multimedia data. It also builds in data security, implementing privacy and authentication services. 802.15.3 operates in the 2.4GHz band at 11, 22, 33, 44, and 55Mbps.
Unlike 802.11 connections, 802.15.3 is designed for peer-to-peer operation rather than routing data through an access point, whether that's a base-station or a client machine configured as one. Access points can become network bottlenecks.
The final spec. is expected to be submitted for IEEE approval in June. In the meantime, an alternative spec., 802.15.3a, is under development to create a higher data PHY to replace the 55Mbps 2.4GHz PHY in 802.15.3. It's increasingly likely that 802.15.3a will be based on ultra-wideband (UWB) technology, but it has to get through selection procedures this month and in July first. However, it has the potential to reach data rates of 100Mbps and ultimately the 400Mbps (at 5m) offered by standard 1394 wired links."
iChat AV uses the industry-standard H.263 video codec and advanced pre- and post-processing techniques to deliver picture-perfect video. It uses the sophisticated
technologies built into QuickTime to compress the video and audio while maintaining rich detail, natural colors, and smooth video over any 100-Kbps or faster Internet connection. Specific technologies include:
Spatial anisotropic diffusion to maintain edge detail and sharpness while reducing
unnecessary digital "noise."
Temporal noise reduction to average out noise between video frames while avoiding
motion blurring.
Post-filtering of the received video to avoid blockiness and ringing artifacts.
iChat AV uses a sophisticated digital audio codec to deliver the same crystal-clear
audio quality that you expect when you use a typical landline telephone. The fullduplex
technology built into iChat AV lets you have natural conversations, just as
with the advanced speakerphones found in conference boardrooms. Most other
solutions force users to talk one at a time, providing an experience more akin to
talking on a CB radio.
Apple has recently announced support for H.264, which is a good thing
"but there's only wireless access in the Commons (like the student union, except more full of offices), the library, and the Administration buildings."
Not quite correct. I worked for Information Tech. Svcs. at UI as an undergrad in 2001 when the wireless network was first installed. Your comment was correct then. Here are the locations today:
Where are wireless connections available?
Administration Building Ag & Extension Education Bldg Ag Biotech Ag Science Art & Architecture Art & Architecture/North Art & Architecture/South Art & Architecture - Interior Design Buchanan Engineering Lab Career Services College of Natural Resources Education/KIVA Engineering/Physics Fo od Research Center Gauss-Johnson Gibb Hall Idaho Commons Industrial Technology (ITED) J.W. Martin Lab JAA-College of Business Janssen Engineering Building Kibbie Dome Law School Library Life Science South McClure Memorial Gym Mines Building Morrill Hall Music Building Navy Building Niccolls Physical Education POLYA (Brink Basement) Radio/TV Building Renfrew Hal Ridenbaugh Hall Shoup Hall Student Recreation Center Student Union Building (SUB) Wallace Common Area
Now, my current Institution, UC Davis, sucks! It did not even make the list, and rightly so. The wireless service is pathetic. I hope somebody from UCD is reading this, because they should be embarassed.
One thing to remember when comparing MPEG4 codecs is that while they may be compatible with MPEG4, the standard (and all video compression standards, generally speaking) only specifies the decoder implementation. The way the encoder works is left to the developer, and it fosters development of the "best" codec.
For example, while the MPEG4 codec may specify that motion vectors are to be used, the way those motion vectors (MV) are generated is left to the implementation. From the results and text, it looks like DivX uses quarter-pel (quarter-pixel) MV calculation, while Apple's MPEG-4 does not. Apple's MPEG4 probably also uses a smaller search range for the motion vectors and larger block size, which makes it a LOT faster.
The conclusions made in the article are reasonable considering the stated goal of the article: evaluation of several consumer codecs with transcoding. However, if original source was used instead of compressed MPEG2 and higher grade professional encoders were used, the results might be a lot different.
I just finished a graduate course in multimedia networking, and have been working with next-generation scalable codecs. All I can say is: wait and see what's coming!!
Yet Another High School Student Who Wants To Be A <insert specific technical job here>.
(Score: 0, Redundant)
I have seen many, many posts to Slashdot from high school students who want to have some technical job and want to know what school to attend. The bottom line is:(and comments like this one are always moderated to the top)it doesn't matter where you get your undergraduate degree. Your undergraduate degree is only a vehicle to teach you the fundamentals of how to think in a particular field. You spend 4+ years just learning the technical language of a field so you can speak intelligently with professionals in that field. Even after you graduate, you will feel like you really don't know anything, and will rely heavily on coworkers during your first job to guide you toward practical use of the broad set of skills you barely learned as an undergrad.
If you are a glutton for punishment, you might choose to return to school for graduate studies, where you will feel even more clueless, but at least your classes will begin to delve into interesting material specific to the area you are interested in. Only when you finish your PhD dissertation will you feel like you are an expert, but your expertise will be in such a focused topic that you will be glad you took all of those other classes as an undergrad so you can actually get a job.
My advice is to go to a school with a good technical reputation, but not necessarily MIT or Stanford. Earn a 4.0, but also enjoy yourself. Your college life as an undergraduate is a great experience. With your high grades from a good school, you won't have any problem getting into great graduate program. On the other hand, it is probably a good idea to get a job and go work for a couple of years so you can get a feel for the industry and decide what you really want to specialize in. Then go to grad school. And get your employer to pay for it. I did.
When I was in high school, I installed a complete wired intercomm system in our auditorium. I have to echo other posters--go with wired, not wireless. No interference problems, battery issues, etc. (Although even wired intercomms can have interferenced issues if not grounded properly. I still have fond memories of speaking with someone on a cordless phone through our closed-circuit intercomm). Wired units are much cheaper, and a professional system like ClearComm or Telex can be upgraded to add wireless units later. Get an intercomm system designed for theater and you will be much happier. Most of the cost of rolling your own system will be the cost of the beltpacks and hardware. Plus, you will want it to be full duplex, and you won't want to share a network like 802.11. Don't forget that internet routing is best effort delivery--and you don't want to lose packets on an intercomm system!! Start small--get a base station for the control booth or stage manager and get a few beltpaks for sound, lighting, spots, and possibly stage crew. Then you can add more units later as your need and your funding increases. To do it right, sit down and plan your ideal system (if funding were no issue), and then decide on a subset to purchase based on your current funding. Take your plan to the administration and sell it as an extensible system that can grow over the years. Next year you can go back to your master plan and figure out what you need next. Also, take the time to plan your infrastructure right. If you install a versatile system with plenty of wall jacks located throughout the facility, you won't have to string cables all over the place for every show. Put wall plates all around the stage, in the middle and rear of the house, in the foyer (if you have one), balcony (if you have one) stage wings, control booth, green room, dressing rooms, and the lighting dimmer/audio amplifier cage. For a smaller facility like mine (we had about 500 seats w/ balcony), 2 channels of intercomm is probably plenty (pro systems come in 2- and 4-channel flavors).
Considering ClearComm vs. Telex, I would go with Telex. It is compatible with ClearComm (unbalanced), but more importantly, it is balanced, so you will have less noise in the system. Also, the standard connectors are balanced 3-pin XLR, meaning they are compatible with balanced audio cables (However, I would buy a separate set of cables for intercomm use, and make them a different color, like blue - Clark Wire & Cable. This makes it easier to identify which cables are audio and which are intercomm and also ensures you won't use a beat-up intercomm cable for audio!). Also, Telex beltpacks are more rugged (metal, not plastic), and they look better!
Look at Full Compass for intercomm hardware. They have good prices. Hope some of this is useful.
"President Bush has stated that in order to ensure the highest chances of a success for a manned mission to the moon, the mission will only be launched during a full moon..."
Slashdot Mirror
Coming Soon: Links to a minivan review article and a discussion of play-date etiquette. Seriously, how is this News for Nerds. Stuff that matters?
This may be obvious, but: 1. Don't network this computer. 2. Implement physical access controls. 3. Require strong passwords. 4. Isolate this computer from all other electronic and RF sources to comply with TEMPEST requirements. 5. Don't ask these sorts of questions on Slashdot. You have already compromised OPSEC.
from the site:
FreeHeel
iPod compatible? Sounds like Real Networks to me. But I still don't know how they will get the music into your iPod catalog w/o iTunes integration, which Apple is unlikely to give up...
What about the Iomega micro-mini?
The Iomega web site says that it is USB 2, and it is really small, which I like. The rotating cap is cool too. Needs a write-protect switch, though...
I don't speak Japanese, but shouldn't the acronym for ariable spreading factor orthogonal frequency code division multiplexing be VSF-OFCDM?
Since 2.4 GHz is an ISM band, there are no license requirements, and there are already many proprietery transceivers on the market. The difference here is that Zigbee (802.15.4) is an IEEE std. ZigBee was developed because many felt Bluetooth was too complicated for sensor network and automation type applications. Indeed, with the Piconet scheme of 7 active nodes, large Bluetooth networks are very complicated, and I don't think the problems associated with large meshes of piconets have been solved. ZigBee is supposed to be lower power, and it uses a more robust DSSS transceiver. It also implements some additional security protocols. However, the data rate is at best 4x slower. Bluetooth has applications in one market segment, namely personal computing, and ZigBee in another (sensors, automation).
There is room for each protocol in the appropriate vertical marketplace, and no one protocol is appropriate for everything. Think of 802.11a/b/g, Bluetooth, and ZigBee as FireWire, USB, and... serial.
Team targets 802.15.3 for wireless video networks
This sounds like a great improvement to 802.11x technology...now let's open-source it so we can all benefit!
I am not a robot engineer, but this look like state-of-the-art to me...
Here is a cool NASA photo that shows the peak.
If you look really close, you can see the shuffleboard court on the aft promenade deck.
Apple has recently announced support for H.264, which is a good thing
Not quite correct. I worked for Information Tech. Svcs. at UI as an undergrad in 2001 when the wireless network was first installed. Your comment was correct then. Here are the locations today:
U of I Wireless Network
Now, my current Institution, UC Davis, sucks! It did not even make the list, and rightly so. The wireless service is pathetic. I hope somebody from UCD is reading this, because they should be embarassed.
For example, while the MPEG4 codec may specify that motion vectors are to be used, the way those motion vectors (MV) are generated is left to the implementation. From the results and text, it looks like DivX uses quarter-pel (quarter-pixel) MV calculation, while Apple's MPEG-4 does not. Apple's MPEG4 probably also uses a smaller search range for the motion vectors and larger block size, which makes it a LOT faster.
The conclusions made in the article are reasonable considering the stated goal of the article: evaluation of several consumer codecs with transcoding. However, if original source was used instead of compressed MPEG2 and higher grade professional encoders were used, the results might be a lot different.
I just finished a graduate course in multimedia networking, and have been working with next-generation scalable codecs. All I can say is: wait and see what's coming!!
(Score: 0, Redundant)
I have seen many, many posts to Slashdot from high school students who want to have some technical job and want to know what school to attend. The bottom line is: (and comments like this one are always moderated to the top) it doesn't matter where you get your undergraduate degree. Your undergraduate degree is only a vehicle to teach you the fundamentals of how to think in a particular field. You spend 4+ years just learning the technical language of a field so you can speak intelligently with professionals in that field. Even after you graduate, you will feel like you really don't know anything, and will rely heavily on coworkers during your first job to guide you toward practical use of the broad set of skills you barely learned as an undergrad.
If you are a glutton for punishment, you might choose to return to school for graduate studies, where you will feel even more clueless, but at least your classes will begin to delve into interesting material specific to the area you are interested in. Only when you finish your PhD dissertation will you feel like you are an expert, but your expertise will be in such a focused topic that you will be glad you took all of those other classes as an undergrad so you can actually get a job.
My advice is to go to a school with a good technical reputation, but not necessarily MIT or Stanford. Earn a 4.0, but also enjoy yourself. Your college life as an undergraduate is a great experience. With your high grades from a good school, you won't have any problem getting into great graduate program. On the other hand, it is probably a good idea to get a job and go work for a couple of years so you can get a feel for the industry and decide what you really want to specialize in. Then go to grad school. And get your employer to pay for it. I did.
[I am a graduate student in EE. YMMV]
Considering ClearComm vs. Telex, I would go with Telex. It is compatible with ClearComm (unbalanced), but more importantly, it is balanced, so you will have less noise in the system. Also, the standard connectors are balanced 3-pin XLR, meaning they are compatible with balanced audio cables (However, I would buy a separate set of cables for intercomm use, and make them a different color, like blue - Clark Wire & Cable. This makes it easier to identify which cables are audio and which are intercomm and also ensures you won't use a beat-up intercomm cable for audio!). Also, Telex beltpacks are more rugged (metal, not plastic), and they look better! Look at Full Compass for intercomm hardware. They have good prices. Hope some of this is useful.
FreeHeel
"President Bush has stated that in order to ensure the highest chances of a success for a manned mission to the moon, the mission will only be launched during a full moon..."
I didn't know Al Gore worked for DARPA.
Consider a PowerBook G4. The 12" model is even smaller and more powerful than the iBook. You can run LinuxPPC or YellowDog Linux on it too.