Nature Sound Clips
Free, public domain sound clips available from the US Fish and Wildlife Service. Includes ducks, geese, loons, shorebirds, alligators, frogs, snakes, bats, bears, elk, wolves, and others. Pretty neat!
Rosenbrock’s Banana Function
In mathematical optimization, Rosenbrock’s Banana Function is a non-convex function used as a test problem for optimization algorithms.
This function is often used to test performance of optimization algorithms. The global minimum is inside a long, narrow, parabolic shaped flat valley. To find the valley is trivial, however to converge to the global minimum is difficult.
It is defined by
f(x, y) = (1 – x)^2 + 100(y – x^2)^2
It has a global minimum at (x, y) = (1, 1) where f(x, y) = 0. A different coefficient of the second term is sometimes given, but this does not affect the position of the global minimum.
Rosenbrock 's Banana Function
White Castle Building No. 8
White Castle Building Number 8 is a White Castle restaurant building in Minneapolis, Minnesota. It was one of the few prefabricated, portable buildings built by the chain, and is presently operated as a jewelry store.
The building, measuring only 28 feet by 28 feet, has had three different locations in Minneapolis. The restaurant was originally located at 616 Washington Avenue Southeast near the University of Minnesota campus in the Stadium Village neighborhood in 1936. In 1950, the building was moved to 329 Central Avenue Southeast when the owner of the Washington Avenue property refused to renew the lease. In 1983, White Castle officials opened a new, larger restaurant a few blocks away from the Central Avenue location.
In order to save a piece of the city's architectural history, the Minneapolis Heritage Preservation Commission found a buyer willing to relocate the structure and save it from demolition. The building is now located at 3252 Lyndale Avenue South, and was added to the National Register of Historic Places in 1986.
via White Castle Building No. 8 – Wikipedia, the free encyclopedia.
Cloud Factory
The Cloud Factory is an affectionate euphemism for a boiler plant which billows steam from below its twin stacks in The Mysteries of Pittsburgh, the 1988 debut novel by the Pulitzer Prize-winning American writer Michael Chabon. Bellefield Boiler Plant, the actual name of the facility, is located in Junction Hollow (affectionately known as “The Lost Neighborhood” also in Chabon’s book) behind Carnegie Mellon University in the Oakland district of Pittsburgh, Pennsylvania.
Built in 1907 to provide steam heat for the Carnegie, it was designed in the Romanesque Revival style by the architectural firm Longfellow, Alden, and Harlow. One of the smoke stacks measures 150 feet and the other more than 200 feet. The plant has burned both coal and natural gas but will cease using coal on July 1, 2009. Its steam system expanded in the 1930s to service the University of Pittsburgh’s Cathedral of Learning. Today it pumps heat to most of the major buildings in Oakland. It is owned by a consortium made up of the University of Pittsburgh, University of Pittsburgh Medical Center, Carnegie Mellon University, the Carnegie, the City of Pittsburgh, and the Pittsburgh Public Schools.
Mount CD ISO image in Windows XP without Daemon Tools/Alcohol 120
Here’s a small but unsupported tool from Microsoft to let you mount ISO images. The included readme file is pretty good, and it worked just fine for me.
Velocipede, not Velociraptor
Whenever I write about velociraptors, my spellchecker always suggests “velocipede” as the word I’m most likely trying to spell. Curiosity eventually got the better of me, so I looked up the meaning of this rather odd word:
The velocipede was a series of human-powered vehicles created in the late Georgian era. There were designs with two, three and four wheels. Some two-wheeled designs had pedals mounted on the front wheel, while three- and four-wheeled designs used treadles and levers to drive the rear wheels. Later two-wheel versions had increasingly large front wheels, directly driven by bicycle pedals, and a smaller back wheel—these leading to the penny-farthing.
Now you know…
Shabbat Mode
Sabbath mode is a feature in many modern appliances, including ovens and refrigerators which is intended to allow the appliances to be used (subject to various constraints) by Sabbath-observant Jews on the Sabbath and Jewish holidays.
One of the Sabbath laws is that raw food may not be cooked on the Sabbath, but food which was already cooked beforehand may be kept warm until mealtime. On holidays, food may be cooked fresh, but turning the flame on is problematic. In the past, both of these could be accomplished simply by lighting a flame before the day begins, and using its heat over the course of the day. In recent decades, however, appliance manufacturers have instituted a safety feature which automatically shuts off the heat after a number of hours. This renders the appliance useless for those who observe these religious laws.
The key features of Sabbath mode ovens are that it disables the standard six- or twelve-hour cutoff and all lights and displays are disabled, so that no visible activity takes place when the oven door is opened.
In more recent ovens, Sabbath mode will often feature the ability to adjust the temperature of the oven without any feedback to the operator of the oven. This is not relevant to the Sabbath, but is useful on holidays, when adjusting the heat is allowed, but changing a digital readout on the control panel is not, according to the prevailing Orthodox opinion and the minority Conservative view.
With some Sabbath mode ovens that are controlled using a keypad to set the temperature, there is a pseudo-random delay triggered after a button is pressed before the temperature change takes place.
Those who feel that hitting the keypad closes a switch and that completing a circuit is not allowed do have other options, such as the “Tweaker” which was featured on the TorahTechnologies.org web site that emulates old manual ovens by adding a knob that confuses the accurate temperature measurement in a beneficial fashion.
A Sabbath mode refrigerator includes, at a minimum, the ability to disable all lights or other electrical activity from occurring when the refrigerator door is opened. Some Sabbath mode refrigerators include a timer for the compressor so that opening the door, which will normally indirectly cause the compressor to turn on as the temperature rises, will have absolutely no effect on any electrical operation of the appliance.
See also:
Saturation Arithmetic
Saturation arithmetic is a version of arithmetic in which all operations such as addition and multiplication are limited to a fixed range between a minimum and maximum value. If the result of an operation is greater than the maximum it is set (”clamped”) to the maximum, while if it is below the minimum it is clamped to the minimum. The name comes from how the value becomes “saturated” once it reaches the extreme values; further additions to a maximum or subtractions from a minimum will not change the result.
Typically, early computer microprocessors did not implement integer arithmetic operations using saturation arithmetic; instead, they used the easier-to-implement modular arithmetic, in which values exceeding the maximum value “wrap around” to the minimum value, like the hours on a clock passing from 12 to 1. In hardware, modular arithmetic with a minimum of zero and a maximum of 2n can be implemented by simply discarding all but the lowest n bits.
However, although more difficult to implement, saturation arithmetic has numerous practical advantages. The result is as numerically close to the true answer as possible; it’s considerably less surprising to get an answer of 127 instead of 130 than to get an answer of −126 instead of 130. It also enables overflow of additions and multiplications to be detected consistently without an overflow bit or excessive computation by simple comparison with the maximum or minimum value (provided the datum is not permitted to take on these values).
Additionally, saturation arithmetic enables efficient algorithms for many problems, particularly in digital signal processing. For example, adjusting the volume level of a sound signal can result in overflow, and saturation causes significantly less distortion to the sound than wrap-around.
via Saturation arithmetic – Wikipedia, the free encyclopedia.
Using command line arguments in Python in IDLE.
I’m not a big fan of integrated development environments (IDEs), but they can be nice to help people get introduced to a new language, or even to programming in general. Processing and Arduino wouldn’t be as easy for new people to use if they didn’t have a decent IDE.
Most useful scripts accept command line arguments to configure their behavior, but sometimes it is difficult to set command line parameters from within an IDE. I was recently working on a python project with a friend living in Florida, new to the world of programming, so I showed him how to use Python’s IDLE interface, a nice IDE for Python work. Unfortunately, there is no way to set command line arguments from IDLE, so our scripts weren’t working in the IDE. I found a way to manually set the command line arguments if a Python script is run from IDLE, but doesn’t interfere if the script is run from the console.
To use, insert this code right after the start of your main-line code, right before you do your parsing and validation of the input parameters. Be sure that the specified arguments below match what your program is expecting.
try:
__file__
except:
sys.argv = [sys.argv[0], 'argument1', 'argument2', 'argument2']
Azertyuiop
Azertyuiop is a top-class 2 mile National Hunt steeplechase horse. He won the Arkle Challenge Trophy at the 2003 Cheltenham Festival, going on to win the Queen Mother Champion Chase the following year, and then coming home third in the same race in 2005. He was trained by Paul Nicholls and was ridden by Ruby Walsh in every chase bar one. He is owned by John Hales who also owned One Man, who won the 1998 Queen Mother Champion Chase and the 1995 and 1996 King George VI Chase. His name derives from the top row of letters on the French keyboard layout.