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Programming

Performance Bugs, 'the Dark Matter of Programming Bugs', Are Out There Lurking and Unseen (forwardscattering.org) 266

Several Slashdot readers have shared an article by programmer Nicholas Chapman, who talks about a class of bugs that he calls "performance bugs". From the article: A performance bug is when the code computes the correct result, but runs slower than it should due to a programming mistake. The nefarious thing about performance bugs is that the user may never know they are there -- the program appears to work correctly, carrying out the correct operations, showing the right thing on the screen or printing the right text. It just does it a bit more slowly than it should have. It takes an experienced programmer, with a reasonably accurate mental model of the problem and the correct solution, to know how fast the operation should have been performed, and hence if the program is running slower than it should be. I started documenting a few of the performance bugs I came across a few months ago, for example (on some platforms) the insert method of std::map is roughly 7 times slower than it should be, std::map::count() is about twice as slow as it should be, std::map::find() is 15% slower than it should be, aligned malloc is a lot slower than it should be in VS2015.
Security

New Technology Combines Lip Motion and Passwords For User Authentication (bleepingcomputer.com) 54

An anonymous reader writes: "Scientists from the Hong Kong Baptist University (HKBU) have developed a new user authentication system that relies on reading lip motions while the user speaks a password out loud," reports BleepingComputer. Called "lip password" the system combines the best parts of classic password-based systems with the good parts of biometrics. The system relies on the uniqueness of someone's lips, such as shape, texture, and lip motions, but also allows someone to change the lip motion (password), in case the system ever gets compromised. Other biometric solutions, such as fingerprints, iris scans, and facial features, become eternally useless once compromised.
Math

This Is How the Number 3.14 Got the Name 'Pi' (time.com) 133

An anonymous reader shares a Time article: Ancient research on real numbers likely "didn't get improved upon until the age of Newton," says John Conway, mathematics professor emeritus at Princeton University who once won the school's Pi Day pie-eating contest. Sir Isaac Newton recorded 16 digits of pi in 1665, later admitting that he was "ashamed" of how long he had worked on the computations, as it meant that he had "no other business at the time," per the MAA. It was not until the 18th century -- about two millennia after the significance of the number 3.14 was first calculated by Archimedes -- that the name "pi" was first used to denote the number. In other words, the Greek letter used to represent the idea was not actually picked by the Ancient Greeks who discovered it. British mathematician William Jones came up with the Greek letter and symbol for the figure in 1706, and it was popularized by Swiss mathematician Leonhard Euler, Catherine the Great's mathematician, a few decades later. "Euler was a much better mathematician than the people who used [pi] before, and he wrote very good textbooks," says Conway. "He used it because the Greek letter Pi corresponds with the letter 'P'... and pi is about the perimeter of the circle."

Comment Skeptics will fail (Score 1) 31

If you /. complainers don't think both autonomous and HAD (highly-assisted driving) is going to be a gigantic market,you're not paying any attention.
I am paying attention, mostly 'cause I work for one of the companies making radar & camera products for these functions, and partly 'cause I like the neat things my Tesla can do :-) .
The fact is that there's going to be zillions of dollars' worth of contracts from car mfrs for sensors, processing algorithms, and control algorithms. Intel wants in on that.

Businesses

Tech's Ruling Class Casts a Big Shadow (theverge.com) 74

Veteran technology columnist Walt Mossberg believes that Google, Apple, Microsoft, Amazon, and Facebook, or Gang of Five -- as he likes to call them, are casting a big shadow over how today's startups foster, a phenomenon he believes will continue to happen over the years to come. From his column for The Verge: What we have now in consumer tech, in 2017, is an oligopoly, at least superficially similar to the old industrial-era American corporate groups that once dominated key industries. I think that their enduring and growing power casts a shadow over the Silicon Valley legend that there are lots of great new consumer tech innovations being incubated right now in garages or dorm rooms somewhere that will be taken all the way to becoming great companies, the way each of the Gang of Five was. What I fear is more likely to happen to any such startup is that, if they're good, they get acquired by a member of the Gang, or that their idea is turned into a feature for one of the Gang's products. And, even if that never happens and a startup thrives, too often it can only thrive by being successful on a platform controlled by one or more Gang members, with the big guy maybe taking a cut. For instance, Snap, the parent company of Snapchat, which went public last week, famously spurned a $3 billion takeover offer from Gang member Facebook in 2013. But it depends for its very operation on the cloud services of Google and on the mobile app platforms of Apple and Google. And plenty of other companies which either presented threats or opportunities to the Gang have been snapped up by them. Each of the five companies actively scoops up numerous smaller companies every year, in many cases just for their talent and / or patents. In fact, I'd be amazed if there weren't plenty of startups whose main goal is to be purchased by the Gang.

Comment Re: Who's Responsibility? (Score 1) 246

Bobs hacked Samsung TV is not a national security issue

It is when Bob is the son of a general and the television is used to eavesdrop on conversations of classified material in his house.

SRSLY? If some jackass general is discussing classified info outside of an approved secure area, that's the national security issue. He should be court-martialed. That said, catching him in the act in his own home should be preceded with issuance of a valid warrant.

Comment and yet I have neither (Score 1) 70

I'm not bragging, nor am I whining: just stating a fact. I don't understand why people need a DVR when every show and its brother is available via OnDemand. NetFlix I could see as a possibility if I were suddenly laid off, deathly ill, and could do nothing but lie on a couch and watch shows.
Since I'm not, I've got a job, books, the cello, tennis, and about a dozen other hobbies, leaving only a few hours a week for screen-eyeball time anyway. (and when the heck is Orphan Black coming on?)

Comment wishing for rant-free comments (Score 4, Insightful) 71

Is there even ONE slashdotter who's going to comment on the **contents** of the catalog instead of bitching about governments and copyright issues (of which they most likely know very little)?

I'd be much more interested in reviews/ ratings of software tools for various tasks than in what NASA allegedly is or isn't keeping from the public.

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