Who needs sunlight? In Arizona, solar power never sleeps

Posted on by

In a parabolic trough plant like Solana, the mirrors are curved inward, with a glass tube running along the deepest point, or trough, of each mirror. The tube is full of synthetic oil (also known as heat transfer fluid, or HTF). The concave mirrors concentrate light onto this HTF, heating it to 740 degrees Fahrenheit. The system is extremely efficient in collecting heat and concentrating it to a blistering level; when I asked what would happen if I touched the tube, the reply was a curt “Trust me, you definitely don’t want to do that.”

Once the oil is up to temperature, about 270 miles of pipe transport it to the power block, where the HTF takes one of two pathways, depending on Solana’s current needs.

via Who needs sunlight? In Arizona, solar power never sleeps | Ars Technica.

Are We Shooting Ourselves in the Foot with Stack Overflow?

Posted on by

Unless you’ve been living under a rock for a past couple of years, you must have heard of the Toyota unintended acceleration (UA) cases, where Camry and other Toyota vehicles accelerated unexpectedly and some of them managed to kill people and all of them scared the hell out of their drivers.

The recent trial testimony delivered at the Oklahoma trial by an embedded guru Michael Barr for the fist time in history of these trials offers a glimpse into the Toyota throttle control software. In his deposition, Michael explains how a stack overflow could corrupt the critical variables of the operating system (OSEK in this case), because they were located in memory adjacent to the top of the stack. The following two slides from Michael’s testimony explain the memory layout around the stack and why stack overflow was likely in the Toyota code (see the complete set of Michael’s slides).

via Are We Shooting Ourselves in the Foot with Stack Overflow? « State Space.

WhatsApp, Bought by Facebook for $19 Billion, Promotes a Radical Anti-Corporate Message

Posted on by

The eye-popping price tag—about one-tenth the entire value of Facebook—is the shocker that’s drawn much media notice. But there’s another element to the story that is astounding: Koum and Acton have published a manifesto that radically critiques the foundation of modern capitalism—advertising—and denounces materialism. Facebook’s business model, of course, depends upon both.

via WhatsApp, Bought by Facebook for $19 Billion, Promotes a Radical Anti-Corporate Message | Mother Jones.

Will Koum and Acton become part of the Borg they so eloquently decried? The first rule of Fight Club was “You do not talk about fight club.” The second rule was “You do not talk about fight club.” Now that Koum and Acton are billionaires and über-players on the tech scene, will they continue to spread their anti-consumerism, tech-is-for-the-people gospel? Will they change Facebook, or will Facebook change them?

Open Source Programming to the Software-Defined Network

Posted on by

Today, OpenDaylight is an open source platform for network programmability to enable SDN and create a solid foundation for Network Functions Virtualization (NFV) for networks at any size and scale. OpenDaylight software is a combination of components including a fully pluggable controller, interfaces, protocol plug-ins, and applications. The Northbound (programmatic) and Southbound (implementation) interfaces are meant to be clearly defined and documented APIs for network applications.

via OpenDaylight: Open Source Programming to the Software-Defined Network.

OpenDaylight delivered its first developer release, Hydrogen, on February 5th, 2014.

Home Routers Pose Biggest Consumer Cyberthreat

Posted on by

Of the small-office, home-office routers evaluated, every one could be compromised with relative ease by hijacking DNS connections, exploiting HTTPS flaws, weaknesses in Universal Plug and Play services, cross-site-scripting attacks, file-traversal and source-code vulnerabilities, weaknesses in WiFi Protected Setup (WPS), buffer overflows or simply bypassing authentication requirements.

via Home Routers Pose Biggest Consumer Cyberthreat.

During late 2013 and early 2014, gangs of Polish hackers have robbed thousands of consumers by attacking home routers and changing DNS settings so they point at the attackers’ DNS servers rather than legitimate servers.

DNS is a big problem.  Usually devices behind a SOHO router will receive their DNS info from the router via DHCP.  The router has been configured by the owner using DNS settings from their ISP or they could use one of Google’s servers like 8.8.8.8.  A user of their home network should expect a higher level of security unlike the open wifi people use on the road.

The simplest remedy is never allow router management access from the Internet.  This is usually turned off by default.  Routers should be set and forget so using the maintenance interface should be a rare occurrence.  The TP-LINK outlined here requires a user to click a malicious link while in a management session according to this:

Attack Requirements

  • The victim must have an active management session with the WR1043N.
  • The victim must be fooled in to performing an action (e.g., by clicking an attacker provided link), browse to a malicious or compromised site, or be the victim of a man-in-the-middle attack.

Here again the user gets tricked into becoming compromised so this wouldn’t be a problem if the user simply entered the management interface of the router, made changes, and left. There’s no point lingering around in a management session.

A physical dedicated firewall sitting between the Internet and treating all routers as dumb access points makes for an added layer of security.  All SOHO routers are relatively cheap embedded devices.  It is impractical to even expect them to defend against all possible exploits.  By virtue of being on the Internet everyone gets constantly scanned by bots.  That only poses a problem if the bot sees a vulnerability and phones home listing your device as a possible target.

Math Explains Likely Long Shots, Miracles and Winning the Lottery

Posted on by

So let’s look at the probability that none of the 23 people in the room share the same birthday. For two people, the probability that the second person doesn’t have the same birthday as the first is 364/365. Then the probability that those two are different and that a third doesn’t share the same birthday as either of them is 364/365 × 363/365. Likewise, the probability that those three have different birthdays and that the fourth does not share the same birthday as any of those first three is 364/365 × 363/365 × 362/365. Continuing like this, the probability that none of the 23 people share the same birthday is 364/365 × 363/365 × 362/365 × 361/365 … × 343/365.

This equals 0.49

via Math Explains Likely Long Shots, Miracles and Winning the Lottery – Scientific American.

Calculating distance between longitude and latitude pairs

Posted on by

Problem: I need a simple way to calculate distance between two pairs of longitude and latitude coordinates.

Apparently there are several ways of making this calculation.  Since none of my calculations would exceed 15 miles I was able to use the flat earth calculation which is the simplest but inaccurate as distances increase between the two points according to this wikipedia article.  Here’s a blurb about the flat-earth formula:

Flat-surface formula

A planar approximation for the surface of the earth may be useful over small distances. The accuracy of distance calculations using this approximation become increasingly inaccurate as:

  • The separation between the points becomes greater;
  • A point becomes closer to a geographic pole.

There were a bunch of sites that came up with all the different formulae over this but I’m not launching a satellite or programming a guided missile. The following code came from perlmonks which is a very reputable reference for anything to do with programming in perl. Here is the subroutine I chose to use. Article was written in 2002.


use Math::Trig
sub FlatEarth {
my ($lat1, $long1, $lat2, $long2) = @_;
my $r=3956; my $a = (pi/2)- deg2rad($lat1);
my $b = (pi/2)- deg2rad($lat2)
my $c = sqrt($a**2 + $b**2 - 2 * $a *$b *cos(deg2rad($long2)-deg2rad($long1)));
my $dist = $c * $r; return $dist;
}

Via Finding the Distance between longitude and latitude pairs.

The above code seems to work.  Most of the calculations I needed to do were under a mile.

Responding to Potential Asteroid Redirect Mission Targets

Posted on by

NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth’s moon for future exploration by astronauts in the 2020s.

ARM will use capabilities in development, including the new Orion spacecraft and Space Launch System (SLS) rocket, and high-power Solar Electric Propulsion. All are critical components of deep-space exploration and essential to meet NASA’s goal of sending humans to Mars in the 2030s. The mission represents an unprecedented technological feat, raising the bar for human exploration and discovery, while helping protect our home planet and bringing us closer to a human mission to one of these intriguing objects.

via Responding to Potential Asteroid Redirect Mission Targets | NASA.

Here is an article from 12/24/2012 about this.

Comcast’s Time Warner Deal Is Bad for America

Posted on by

The reason this deal is scary is that for the vast majority of businesses in 19 of the 20 largest metropolitan areas in the country, their only choice for a high-capacity wired connection will be Comcast. Comcast, in turn, has its own built-in conflicts of interest: It will be serving the interests of its shareholders by keeping investments in its network as low as possible — in particular, making no move to provide the world-class fiber-optic connections that are now standard and cheap in other countries — and extracting as much rent as it can, in all kinds of ways. Comcast, for purposes of today’s public , is calling itself a “cable company.” It no longer is. Comcast sells infrastructure subject to neither competition nor a cop on the beat.

via Comcast’s Time Warner Deal Is Bad for America – Bloomberg.