Announcing: Slashdot Deals - Explore geek apps, games, gadgets and more. (what is this?)

Thank you!

We are sorry to see you leave - Beta is different and we value the time you took to try it out. Before you decide to go, please take a look at some value-adds for Beta and learn more about it. Thank you for reading Slashdot, and for making the site better!



A Thousand Kilobots Self-Assemble Into Complex Shapes

stepho-wrs Re:Why not just do a software simulation? (56 comments)

From past experience, simulators are great for replicating known scenarios (including a limited set of failure scenarios).
But real, physical things will fail in strange ways that are hard to predict or can be hard to simulate.
Eg, perhaps some of them have a slight tendency to lean to the left (uneven legs during manufacturing), some of them might be intermittently blind on the right side but only when turning right (maybe manufacturing machine leaves a dry joint when soldering the right sensor, not found during stationary testing), parts start to fail intermittently as they age, the vibration of 10 neighbours is enough to cause trouble to one robot equi-distance from them all, etc.

about 6 months ago

Can Our Computers Continue To Get Smaller and More Powerful?

stepho-wrs Re:Considering (151 comments)

Making it much easier to read the 3 characters that fit on the 5" screen...

about 6 months ago

Unisys Phasing Out Decades-Old Mainframe Processor For x86

stepho-wrs Re:9 bits byte (113 comments)

A lot of the 1960's big iron had 9 bit bytes - eg the venerable DEC-10. They need 36 bits to represent the range of data they wanted (typically floating point). Those 36 bits could only be divided according to 36 = 2x2x3x3 (ie chunks of 1, 2, 3, 4, 6, 9, 12, 18). Some used 6 bits to represent a character in a very limited character set, some used 9 bits to a character (not all bit values necessarily corresponded to a printable character). The big change to 8 bit bytes came from the IBM 360 when it choose 32 bits (32 = 2x2x2x2x2) and it's easy division into 1,2,4,8,16 chunks. The 9 bit byte was the standard and the 8 bit byte was the incompatible new kid on the block. Which is why the ITU says the unambiguous 'octet' instead of the ambiguous 'byte'.

about 7 months ago

Is It Really GPS If It Doesn't Use Satellites?

stepho-wrs Re:Well ... (298 comments)

Didn't Ben Rich mention this in his "Skunk Works" book?

about 8 months ago

Book Review: Designing With the Mind In Mind

stepho-wrs Re:How do you get decision-makers to follow it? (52 comments)

Alan Cooper (the father of Visual Basic) had an excellent book called 'About Face'. He made that exact point about GUI controls having affordance.

about 9 months ago

Experts Say Hitching a Ride In an Airliner's Wheel Well Is Not a Good Idea

stepho-wrs Re:units (239 comments)

Likewise, I find Fahrenheit confusing every time I visit the US. 15-30C is comfortable (I live near a desert), 45C is try not to move weather (2 weeks in January) and 5C is wear a jacket weather. I can remember 100F only because I know it is body temperature (approx 37/38C). When visiting the US I usually make a little lookup table on a scrap of paper to convert between C and F.

about 9 months ago

Remote ATM Attack Uses SMS To Dispense Cash

stepho-wrs encrypted (150 comments)

ATM's make heavy use of encryption. Sensitive data (eg customer PIN) is encrypted so that you can not decode it. Unencrypted data is not sensitive (eg the dollar amount of the transaction). Each packet sent to the bank host is digitally signed. Each packet received from the host is also checked for its digital signature. The digital signatures have the time as part of the generation algorithm, so replay attacks don't work. If you monitored traffic on that cable then you would get a log of who took out money, the account number, the amount, the time and possibly how much was left in their account. You would get similar information by ransacking the receipt bin. If you tried to inject or replay packets in either direction then they would be rejected. I used to design EFTPOS credit card terminals. We designed them with the understanding that malicious people would be listening to everything on the cable and they would be trying to inject malicious data at every opportunity. Note that the cable might be ethernet, phone (ie modem), X.25, serial or a handful of less common types but the above applies to all of them. The worst you could really do is to cut that cable and deny the service to the customers.

about 10 months ago

Why Nissan Is Talking To Tesla Model S Owners

stepho-wrs not worse (335 comments)

He said the Model S was in cat A (better, more expensive).
It's the **Leaf** that he said was in Cat D (worse, more expensive).

about a year ago

US Carriers Said To Have Rejected Kill Switch Technology Last Year

stepho-wrs Not a problem. (197 comments)

Only a problem in countries where the government censors and restricts the public. We're talking about the US, so ..... oh, nevermind.

about a year ago

New 360-Degree Video Capture Method Unveiled

stepho-wrs No blind spots (58 comments)

No blind spots - until a glitch disables your goggles... :)

about a year ago

Will Electric Cars and Solar Power Make Gasoline and Utilities Obsolete?

stepho-wrs Re:Um, nice, but not so fast (734 comments)

Home solar works better with a utility using hydro.
The utility allows the water in the high dam to fall down into the low dam, generating electricity using turbines.
Ideally your solar could be used to pump some of that water from the low dam back to the high dam.
At night time, the water can flow down again.
The two dams become a huge battery.

I believe many utilities already do this in reverse.
Average day time power is provided by gas/oil/coal/etc to cover slightly less than peak.
At night time, when user demand is lower, the excess power is used to pump the water up to the high dam.
Back in daytime again, the peak demand is provided by allowing the water to go down again through turbines.
Thus the gas/oil/coal/etc generators can be smaller as the production of electricity is spread across the entire 24 hours instead of at peak time.

1 year,7 days

Office Space: TV Documentary Looks At the Dreadful Open Office

stepho-wrs Re:I like the open plan (314 comments)

Wow, an 8 metre by 8 metre cube? Can I send you my resume?

1 year,7 days

Google Launches Android Automotive Consortium

stepho-wrs Re:QNX (117 comments)

2014 will be the year of Linux on the dashboard...

1 year,24 days

Australian Team Working On Engines Without Piston Rings

stepho-wrs Re:Okay...nice and all... (368 comments)

Wankel apex seals are the equivalent of piston rings - ie a chunk of metal/ceramic that fills the gap between the piston/rotor and the chamber wall.

1 year,24 days

Tesla Model S Battery Drain Issue Fixed

stepho-wrs Re:And, Folks, stay tuned.. (239 comments)

Surely the clock wouldn't flash anything at all if it was off...

about a year ago

Richard Branson 'Determined To Start a Population On Mars'

stepho-wrs Re:Food? (266 comments)

er, I thought you brought the can opener...

more than 2 years ago


stepho-wrs hasn't submitted any stories.


stepho-wrs has no journal entries.

Slashdot Login

Need an Account?

Forgot your password?