I have been doing a lot of OCR, as I study more than 100 old aircraft manuals to see how aviation procedures evolved. I have them all in a database, and it’s useful to search the DB for key terms like V1 and density altitude. In the end, no single OCR program did everything, and I have ended up with 3. (OCR = Optical Character Recognition = takes scanned documents and makes them searchable, copyable, etc.) Here are some notes on my experience, with the goal of saving time for others in the future. Continue reading
(I wrote this primarily for friends and colleagues. I’m posting it on my blog for efficiency/discussion/amendment.) My IT manager recently sent around a warning about phishing attacks. (And I just attended a scary CSE seminar on spear-phishing — but that is another story.) Among his advice was:
You should use a strong password on all UCSD accounts and you should never use the same password on any other account you have,
That’s perennial advice that is both good and impossible. It’s good because many (most?) web sites keep making security mistakes that lead to massive breaches, exposing millions of passwords at a time. (The recent+ 100 million account breach at Target, for example.) It’s impossible because we have a decade or more of experience, research, and discussion that says using unique passwords for each login is completely impractical, and nobody actually does it. Continue reading
I recently visited some friends and colleagues at Wharton to discuss my work on evolution of flying. Naturally, Malaysia Air MH370 came up. We have continued the discussion by email since I got back. Here is a note I wrote, explaining why it’s impossible to preprogram a flight plan so that the pilots could not override it, if they were conscious.
Sid, overriding manual override is designed to be impossible. The pilots always have override. Indeed, the first 2 items on some emergency procedures are:
1) Disengage autopilot
2) Disengage auto throttle
and there are specific buttons to make that easy to do in a hurry. (As well as by going into the Flight computer and reprogramming it, or rebooting it, etc. ) Continue reading
The Telephone Wires of Manhattan, 1887. Switchboards were a big step forward. This picture also shows an advantage of living in a city: better communications. Still true today, except measured in milliseconds.
[edits Jan. 31] A poli sci friend recently blogged about the Ukranian government’s “text that changed the world,” a mass text message thousands of anti-government demonstrators in Kiev. She asked 1) How did the government know who was in the main square of Kiev that day? (Cell phone location) and 2) How did it send the same message to everyone at once? (Mass SMS)
The second question is easy: phone companies routinely provide mass-SMS services to large customers. For example, I’m on the “emergency alert” texting service of UC San Diego’s campus police. It was designed for earthquakes, but it has been used for other kinds of messages “between earthquakes.” The same message goes out to every phone number on their list.
What to do to avoid tracking? Short version: Leave your phone at home. Second best is to shut it off or switch to airplane mode, but those work only if the government is not making an effort to target you.
An interesting question about how much latency is acceptable for UAV operation. http://lnkd.in/dx-BfVk My answer, based partly on my radio control flying experience, is that it depends heavily on the context. 200 milliseconds is too long for stunt flying, but not a problem for flying larger UAVs at higher altitudes. The operator has to “dial in” their reflexes to the situation, just as sailors do with different sizes of sailboats. Here’s an example where low latency is essential:
A seeming paradox is that longer latencies are acceptable only at higher Stages of Control. (See my draft book for discussion of this concept.) At the high end (what I call Computer Integrated Flying), if enough knowledge is embodied in the aircraft, the operator can pull back entirely from flying, and switch to “commanding” the aircraft.
Time to debunk another widely covered press story about wonderful new inventions coming from a tech giant. Ars Technica had one of many articles about Google’s “announcement” of a blood glucose sensor in a contact lens. The discussion after the article is good, as often happens with Ars. Here’s my quick explanation of why the concept will fail. Unfortunately.
Non-invasive glucose testing is the perennial “pot of gold at the end of the rainbow.” Google is not the first to try using tears; the others have failed, and they will too. They say it is “5 years away,” which is equivalent to saying “We have not yet tested it on real diabetics.”
The problem is basically that tears won’t track blood glucose levels closely. Tears are secreted by the lacrimal gland. I’ve never studied it, but the composition of its secretion is sure to depend on a multitude of variables. (Think: sweat, saliva, etc.) Even if a relationship exists and can be quantified “on average,” there will be lags.
It’s possible that a device like this could supplement other measurement systems. But nothing will be as good as actual blood measurements. Therefore finger sticks will always be needed for calibration. The best realistic case is that a contact lens device could serve as an early warning; but finger sticks will still be needed for validation before taking any action.