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Comment: Re:Truly a 1st world problem (Score 3, Interesting) 242

by zenaida_valdez (#42227419) Attached to: FCC Chief Urges FAA To Ease Airplane Electronics Ban

"Pilots can use them, passengers can't?" Here's why. I spent my career in aerospace, the final two years on experiments involving these Electronic Flight Bags (In my case, ruggedized PCs, not iPads.) There has been hundreds of hours of testing, both in labs and aircraft to show that a particular model of iPad will not cause electronic interference to the controls or other safety critical systems... for that particular iPad model only. The pilot can't just go buy the next gen fondle slab and carry it aboard. Only the model and rev that has been approved. New hardware would require the testing process to begin all over again.

So, maybe if the avionics supplier who bought them from Apple and spent a lot of money going through the approval process would allow you access to their proprietary certification data, you could make a case to the FAA to allow you to use --that exact iPad-- during takeoff and landing. Good luck.

Comment: Semiconductors DO degrade. was: Re:The CD format (Score 1) 434

by zenaida_valdez (#40724487) Attached to: Ask Slashdot: Storing Items In a Sealed Chest For 25 Years?

Semiconductors do degrade over time. They're made of pure silicon (an insulator) which has been precisely contaminated in specific places with very small quantities of dopants (e. g. boron, phosphorous) giving one side of the junction an excess of electrons and the other side a scarcity. Over time, the dopants diffuse across the junction, changing the characteristics of the transistor by leveling out the excess/scarcity gradient. A 25 year old transistor will no longer meet it's specs. A diode will have greatly increased reverse leakage. AND gates turn into MAYBE gates.

Some capacitors will degrade quickly, some will last much longer. Ceramic capacitors will last a century, electrolytics at most 20 years. The electrolyte dries out.

Comment: System problem, not software (Score 1) 356

by zenaida_valdez (#37831570) Attached to: Jaguar Recalls 18,000 Cars Over Major Software Fault
This design flaw was baked in before they wrote the first line of code. Before throttle-by-wire, the brake pedal had two independent kill mechanisms: an electrical switch to open the solenoid circuit, and a vacuum valve to dump the vacuum to the throttle servo. Either was sufficient to defeat the cruise control. Now it's all single thread. I don't want to go back to coil and points, but some control systems should have multiple override.

Comment: Plausible deniability (Score 1) 175

by zenaida_valdez (#35315532) Attached to: Tiny Transistors Could Be Used To Track Cash
Plausible deniability: Foil lined wallet. Microwave your cash every night. Wear a floppy brimmed hat and stoop when you buy the newspaper with a $20 at 7-11. They may scan the bill, but the cameras can't see your face. Your change is off the map. Purchase items of value (guns, jewelry) from private sellers with this cash. Sell the same way. Money laundering is a continuum, from a Cayman Islands corporation to painting a friend's house for cash.

Premature optimization is the root of all evil. -- D.E. Knuth

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