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Math

Visualizing Algorithms 50

An anonymous reader writes "Many people reading this site probably have a functional understanding of how algorithms work. But whether you know algorithms down to highly mathematical abstractions or simple as a fuzzy series of steps that transform input into output, it can be helpful to visualize what's going on under the hood. That's what Mike Bostock has done in a new article. He walks through algorithms for sampling, shuffling, and maze generation, using beautiful and fascinating visualizations to show how each algorithm works and how it differs from other options.

He says, "I find watching algorithms endlessly fascinating, even mesmerizing. Particularly so when randomness is involved. ... Being able to see what your code is doing can boost productivity. Visualization does not supplant the need for tests, but tests are useful primarily for detecting failure and not explaining it. Visualization can also discover unexpected behavior in your implementation, even when the output looks correct. ...Even if you just want to learn for yourself, visualization can be a great way to gain deep understanding. Teaching is one of the most effective ways of learning, and implementing a visualization is like teaching yourself."
Math

Improperly Anonymized Logs Reveal Details of NYC Cab Trips 192

mpicpp (3454017) writes with news that a dump of fare logs from NYC cabs resulted in trip details being leaked thanks to using an MD5 hash on input data with a very small key space and regular format. From the article: City officials released the data in response to a public records request and specifically obscured the drivers' hack license numbers and medallion numbers. ... Presumably, officials used the hashes to preserve the privacy of individual drivers since the records provide a detailed view of their locations and work performance over an extended period of time.

It turns out there's a significant flaw in the approach. Because both the medallion and hack numbers are structured in predictable patterns, it was trivial to run all possible iterations through the same MD5 algorithm and then compare the output to the data contained in the 20GB file. Software developer Vijay Pandurangan did just that, and in less than two hours he had completely de-anonymized all 173 million entries.
Programming

Computational Thinking: AP Computer Science Vs AP Statistics? 155

theodp writes: "What if learning to code weren't actually the most important thing?" asks Mother Jones' Tasneem Raja. "Rather than increasing the number of kids who can crank out thousands of lines of JavaScript, we first need to boost the number who understand what code can do." Computational thinking, Raja explains, is what really matters. So, while Google is spending another $50 million (on top of an earlier $40 million) and pulling out all the stops in an effort to convince girls that code and AP Computer Science is a big deal, could AP Statistics actually be a better way to teach computational thinking to college credit-seeking high school students? Not only did AP Statistics enrollment surge as AP CS flat-lined, it was embraced equally by girls and boys. Statistics also offers plenty of coding opportunities to boot. And it teaches one how to correctly analyze AP CS enrollment data!
Biotech

Video Modular Science is Building Hardware and Software for Lab Automation (Video) 6

Modular Science is something Tim Lord spotted at last month's O'Reilly Solid Conference in San Francisco. Its founder, Peter Sand, has a Ph.D. in Computer Science from MIT. He's scheduled to speak at this year's OSCON, and his speaker blurb for that conference says, "He is the founder of ManyLabs, a nonprofit focused on teaching math and science using sensors and simulations. Peter also founded Modular Science, a company working on hardware and software tools for science labs. He has given talks at Science Hack Day, Launch Edu, and multiple academic conferences, including SIGGRAPH." And now he's also been interviewed on Slashdot. Note that there are plenty of lab automation systems out there. Peter is working on one that is not only "an order of magnitude cheaper" than similar devices, but is also easy to modify and expand. It's the sort of system that would fit well not just in a college-level lab, but in a high school lab or a local makerspace. (Alternate Video Link)
Math

The Game Theory of Life 85

An anonymous reader writes In what appears to be the first study of its kind, computer scientists report that an algorithm discovered more than 50 years ago in game theory and now widely used in machine learning is mathematically identical to the equations used to describe the distribution of genes within a population of organisms. Researchers may be able to use the algorithm, which is surprisingly simple and powerful, to better understand how natural selection works and how populations maintain their genetic diversity.
Education

Average HS Student Given Little Chance of AP CS Success 293

theodp (442580) writes AP Computer Science is taught in just 10% of our high schools," lamented The White House last December as President Obama kicked off CSEdWeek. "China teaches all of its students one year of computer science." And the U.S. Dept. of Education has made the AP CS exam its Poster Child for inequity in education (citing a viral-but-misinterpreted study). But ignored in all the hand-wringing over low AP CS enrollment is one huge barrier to the goal of AP-CS-for-all: College Board materials indicate that the average 11th grader's combined PSAT/NMSQT score of 96 in reading and math gives him/her only a 20%-30% probability of getting a score of '3' on the AP CS exam (a score '4' or '5' may be required for college credit). The College Board suggests schools tap a pool of students with a "60-100% likelihood of scoring 3 or higher", so it's probably no surprise that CS teachers are advised to turn to the College Board's AP Potential tool to identify students who are likely to succeed (sample Student Detail for an "average" kid) and send their parents recruitment letters — Georgia Tech even offers some gender-specific examples — to help fill class rosters.
Bitcoin

Bitcoin Security Endangered By Powerful Mining Pool 281

An anonymous reader writes Ars Technica reports that for the first time in Bitcoin's five-year history, a single entity has repeatedly provided more than half of the total computational power required to mine new digital coins, in some cases for sustained periods of time. It's an event that, if it persists, signals the end of crypto currency's decentralized structure."
Debian

Interviews: Bruce Perens Answers Your Questions 224

A while ago you had the chance to ask programmer and open source advocate Bruce Perens about the future of open source, its role in government, and a number of other questions. Below you'll find his answers and an update on what he's doing now.
Education

Interviews: Forrest Mims Answers Your Questions 161

A while ago you had the chance to ask amateur scientist, and author of the Getting Started in Electronics and the Engineer's Mini-Notebook series, Forrest Mims, a number of questions about science, engineering, and a lifetime of educating and experimenting. Below you'll find his detailed answers to those questions.
Math

Why You Shouldn't Use Spreadsheets For Important Work 422

An anonymous reader writes "Computer science professor Daniel Lemire explains why spreadsheets shouldn't be used for important work, especially where dedicated software could do a better job. His post comes in response to evaluations of a new economics tome by Thomas Piketty, a book that is likely to be influential for years to come. Lemire writes, 'Unfortunately, like too many people, Piketty used spreadsheets instead of writing sane software. On the plus side, he published his code ... on the negative side, it appears that Piketty's code contains mistakes, fudging and other problems. ... Simply put, spreadsheets are good for quick and dirty work, but they are not designed for serious and reliable work. ... Spreadsheets make code review difficult. The code is hidden away in dozens if not hundreds of little cells If you are not reviewing your code carefully and if you make it difficult for others to review it, how do expect it to be reliable?'"
Programming

R Throwdown Challenge 185

theodp (442580) writes "'R beats Python!' screams the headline at Prof. Norm Matloff's Mad (Data) Scientist blog. 'R beats Julia! Anyone else wanna challenge R?' Not that he has anything against Python, Matloff adds, but he just doesn't believe that Python or Julia will become 'the new R' anytime soon, or ever. Why? 'R is written by statisticians, for statisticians,' explains Matloff. 'It matters. An Argentinian chef, say, who wants to make Japanese sushi may get all the ingredients right, but likely it just won't work out quite the same. Similarly, a Pythonista could certainly cook up some code for some statistical procedure by reading a statistics book, but it wouldn't be quite same. It would likely be missing some things of interest to the practicing statistician. And R is Statistically Correct.'"
Education

Professors: US "In Denial" Over Poor Maths Standards 688

thephydes (727739) writes "The maths skills of teenagers in parts of the deep south of the United States are worse than in countries such as Turkey and barely above South American countries such as Chile and Mexico. From the article: '"There is a denial phenomenon," says Prof Peterson. He said the tendency to make internal comparisons between different groups within the US had shielded the country from recognising how much they are being overtaken by international rivals. "The American public has been trained to think about white versus minority, urban versus suburban, rich versus poor," he said.'"
Math

Discrete Logarithm Problem Partly Solved -- Time To Drop Some Crypto Methods? 114

An anonymous reader points out this Science Daily report: "Researchers ... have solved one aspect of the discrete logarithm problem. This is considered to be one of the 'holy grails' of algorithmic number theory, on which the security of many cryptographic systems used today is based. They have devised a new algorithm that calls into question the security of one variant of this problem, which has been closely studied since 1976. The result ... discredits several cryptographic systems that until now were assumed to provide sufficient security safeguards. Although this work is still theoretical, it is likely to have repercussions especially on the cryptographic applications of smart cards, RFID chips , etc."
Education

Reading, Writing, Arithmetic, and Lately, Coding 125

theodp (442580) writes "The NY Times reports that the national educational movement in computer coding instruction is growing at Internet speeds. 'There's never been a move this fast in education,' said Elliot Soloway, a professor of education and computer science at the Univ. of Michigan. But, cautions the NY Times' Matt Richtel, it is not clear that teaching basic computer science in grade school will beget future jobs or foster broader creativity and logical thinking, as some champions of the movement are projecting. And particularly for younger children, the activity is more like a video game — better than simulated gunplay, but not likely to impart actual programming skills. 'Some educators worry about the industry's heavy role,' adds Richtel. 'Major tech companies and their founders, including Bill Gates and Facebook's Mark Zuckerberg, have put up about $10 million for Code.org,' which recently announced its CS programs will be rolled out to more than 2 million students — nearly 5% of all U.S. K-12 students — at 30 school districts this fall. Among the 20,000 teachers who Code.org says have signed on is Alana Aaron, a fifth-grade math and science teacher who, with her principal's permission, swapped a two-month earth sciences lesson she was going to teach on land masses for the Code.org curriculum. 'Computer science is big right now — in our country, the world,' she said. 'If my kids aren't exposed to things like that, they could miss out on potential opportunities and careers.'"
Transportation

Traffic Optimization: Cyclists Should Roll Past Stop Signs, Pause At Red Lights 490

Lasrick writes: "Joseph Stromberg at Vox makes a good case for changing traffic rules for bicyclists so that the 'Idaho stop' is legal. The Idaho stop allows cyclists to treat stop signs as yields and red lights as stop signs, and has created a safer ride for both cyclists and pedestrians. 'Public health researcher Jason Meggs found that after Idaho started allowing bikers to do this in 1982, injuries resulting from bicycle accidents dropped. When he compared recent census data from Boise to Bakersfield and Sacramento, California — relatively similar-sized cities with comparable percentages of bikers, topographies, precipitation patterns, and street layouts — he found that Boise had 30.5 percent fewer accidents per bike commuter than Sacramento and 150 percent fewer than Bakersfield.' Oregon was considering a similar law in 2009, and they made a nice video illustrating the Idaho Stop that is embedded in this article."
Math

Brain Injury Turns Man Into Math Genius 208

mpicpp sends in the story of Jason Padgett, a man who developed extraordinary mathematical abilities as the result of brain trauma when he was attacked outside a bar. "Padgett, a furniture salesman from Tacoma, Wash., who had very little interest in academics, developed the ability to visualize complex mathematical objects and physics concepts intuitively. The injury, while devastating, seems to have unlocked part of his brain that makes everything in his world appear to have a mathematical structure 'I see shapes and angles everywhere in real life' — from the geometry of a rainbow, to the fractals in water spiraling down a drain, Padgett told Live Science." "He describes his vision as 'discrete picture frames with a line connecting them, but still at real speed.' If you think of vision as the brain taking pictures all the time and smoothing them into a video, it's as though Padgett sees the frames without the smoothing. "
Technology

Can the Lix 3D Printing Pen Actually Work? 90

szczys (3402149) writes "Brian Benchoff used science and math to prove that the performance shown in the Lix Kickstarter video is questionable at best. Check his evidence and see if he's done an appropriate job of debunking the functionality presented." From the Hackaday post: "While we know the video is an outright misrepresentation of what any USB 3 powered device can do, We can’t figure out if the Lix is a viable product. We’re turning to you. Can you figure out if the Lix pen actually works? All we know is the Lix pen has a 4.5 Watt power supply from a USB 3 port. It’s possible for a USB 3 powered 3D printing pen to work, albeit slowly, but the engineering is difficult and we don’t know if the Lix team has the chops."
NASA

NASA Honors William Shatner With Distinguished Public Service Medal 111

Hugh Pickens DOT Com (2995471) writes "Red Orbit reports that after nearly 50 years of warping across galaxies and saving the universe from a variety of alien threats and celestial disasters, Star Trek's William Shatner was honored with NASA's Distinguished Public Service medal, the highest award bestowed by the agency to non-government personnel. 'William Shatner has been so generous with his time and energy in encouraging students to study science and math, and for inspiring generations of explorers, including many of the astronauts and engineers who are a part of NASA today,' said David Weaver, NASA's associate administrator for the Office of Communications at NASA Headquarters in Washington. 'He's most deserving of this prestigious award.' Past recipients of the NASA Distinguished Public Service Medal include astrophysicist Neil deGrasse Tyson, former NASA Jet Propulsion Laboratory director and Voyager project scientist Edward Stone, theoretical physicist and astronomer Lyman Spitzer, and science fiction writer Robert Heinlein. The award is presented to those who 'have personally made a contribution representing substantial progress to the NASA mission. The contribution must be so extraordinary that other forms of recognition would be inadequate.'"
Biotech

Male Scent Molecules May Be Compromising Biomedical Research 274

sciencehabit (1205606) writes "Scientists have found that mice feel 36% less pain when a male researcher is in the room, versus a female researcher. The rodents are also less stressed out. The effect appears to be due to scent molecules that male mammals (including humans, dogs, and cats) have been emitting for eons. The finding could help explain why some labs have trouble replicating the results of others, and it could cause a reevaluation of decades of animal experiments: everything from the effectiveness of experimental drugs to the ability of monkeys to do math. Male odor could even influence human clinical trials."
Math

Mathematicians Push Back Against the NSA 233

First time accepted submitter Parseval (3632761) writes "The NSA and GCHQ need mathematicians in order to function — they are some of the biggest employers of mathematicians in the world. This New Scientist article by a mathematician describes some of the math behind mass surveillance, and calls on other mathematicians to refuse to cooperate with the NSA/GCHQ while they continue to surveil the entire population. From the article: 'Mathematicians seldom face ethical questions. We enjoy the feeling that what we do is separate from the everyday world. As the number theorist G. H. Hardy wrote in 1940: "I have never done anything 'useful'. No discovery of mine has made, or is likely to make, directly or indirectly, for good or ill, the least difference to the amenity of the world." That idea is now untenable. Mathematics clearly has practical applications that are highly relevant to the modern world, not least internet encryption.'"

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