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🔗 United States 🔗 New York City

This is a list of the longest-lasting incandescent light bulbs.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Military history/German military history 🔗 Firearms 🔗 Military history/European military history

The Heckler & Koch P11 is an underwater firearm developed in 1976 by Heckler & Koch. It has five barrels and each fires a 7.62×36mm dart electrically. Loading is by means of a five-round case. The design resembles that of a pepper-box firearm.

🔗 Soviet Union 🔗 Russia 🔗 History 🔗 Russia/sports and games in Russia 🔗 Gymnastics

The Korbut flip is a gymnastics skill performed on either of two different apparatus. Both were first performed internationally by the Soviet gymnast Olga Korbut.

The more spectacular version of the skill used to be performed on the uneven bars, where the gymnast, from a stand on the high bar, performs a back flip and regrasps the bar. Korbut performed the move at the 1972 Summer Olympics, where it was the first backward release move performed on the uneven bars in international competition. In 1977, Soviet gymnast Elena Mukhina modified the flip by adding a full twist. The movement was later modified in the 1980s when it was performed towards the low bar; that is, the gymnast's flip takes place above the low bar. The Code of Points was later modified to ban standing on the high bar during routines.

The skill is also performed on the balance beam. The move is performed from a standing position and is landed in a straddled position on the beam. This movement has been modified to include twists and piked or tucked legs and is frequently performed in sequence with other movements. Unlike its counterpart on the uneven bars, the Korbut flip on beam is today considered a relatively simple skill, valued at only a "B" level in the 2017 Code of Points.

Other gymnasts who have performed the skill's uneven bars variation include Radka Zemanova (1980), Steffi Kraker (1977), Emily May (1981), Lyubov Bogdanova (1974) and Natalia Shaposhnikova (1976).

🔗 Robotics 🔗 Electronics

Surface-mount technology (SMT) component placement systems, commonly called pick-and-place machines or P&Ps, are robotic machines which are used to place surface-mount devices (SMDs) onto a printed circuit board (PCB). They are used for high speed, high precision placing of a broad range of electronic components, like capacitors, resistors, integrated circuits onto the PCBs which are in turn used in computers, consumer electronics as well as industrial, medical, automotive, military and telecommunications equipment. Similar equipment exists for through-hole components. This type of equipment is sometimes also used to package microchips using the flip chip method.

🔗 Typography

A California job case is a kind of type case: a compartmentalized wooden box used to store movable type used in letterpress printing. It was the most popular and accepted of the job case designs in America. The California job case took its name from the Pacific Coast location of the foundries that made the case popular.

The defining characteristic of the California job case is the layout, documented by J. L. Ringwalt in the American Encyclopaedia of Printing in 1871, as used by San Francisco printers. This modification of a previously popular case, the Italic, it was claimed reduced the compositor's hand travel as he set the pieces of type into his composing stick by more than half a mile per day. In the previous convention, upper- and lowercase type were kept in separate cases, or trays. This is why capital letters are called uppercase and the minuscules are lowercase. The combined case became popular during the western expansion of the United States in the 19th century.

🔗 Mathematics 🔗 Statistics

Itô calculus, named after Kiyosi Itô, extends the methods of calculus to stochastic processes such as Brownian motion (see Wiener process). It has important applications in mathematical finance and stochastic differential equations.

The central concept is the Itô stochastic integral, a stochastic generalization of the Riemann–Stieltjes integral in analysis. The integrands and the integrators are now stochastic processes:

${\displaystyle Y_{t}=\int _{0}^{t}H_{s}\,dX_{s},}$

where H is a locally square-integrable process adapted to the filtration generated by X (Revuz & Yor 1999, Chapter IV), which is a Brownian motion or, more generally, a semimartingale. The result of the integration is then another stochastic process. Concretely, the integral from 0 to any particular t is a random variable, defined as a limit of a certain sequence of random variables. The paths of Brownian motion fail to satisfy the requirements to be able to apply the standard techniques of calculus. So with the integrand a stochastic process, the Itô stochastic integral amounts to an integral with respect to a function which is not differentiable at any point and has infinite variation over every time interval. The main insight is that the integral can be defined as long as the integrand H is adapted, which loosely speaking means that its value at time t can only depend on information available up until this time. Roughly speaking, one chooses a sequence of partitions of the interval from 0 to t and constructs Riemann sums. Every time we are computing a Riemann sum, we are using a particular instantiation of the integrator. It is crucial which point in each of the small intervals is used to compute the value of the function. The limit then is taken in probability as the mesh of the partition is going to zero. Numerous technical details have to be taken care of to show that this limit exists and is independent of the particular sequence of partitions. Typically, the left end of the interval is used.

Important results of Itô calculus include the integration by parts formula and Itô's lemma, which is a change of variables formula. These differ from the formulas of standard calculus, due to quadratic variation terms.

In mathematical finance, the described evaluation strategy of the integral is conceptualized as that we are first deciding what to do, then observing the change in the prices. The integrand is how much stock we hold, the integrator represents the movement of the prices, and the integral is how much money we have in total including what our stock is worth, at any given moment. The prices of stocks and other traded financial assets can be modeled by stochastic processes such as Brownian motion or, more often, geometric Brownian motion (see Black–Scholes). Then, the Itô stochastic integral represents the payoff of a continuous-time trading strategy consisting of holding an amount H_t of the stock at time t. In this situation, the condition that H is adapted corresponds to the necessary restriction that the trading strategy can only make use of the available information at any time. This prevents the possibility of unlimited gains through clairvoyance: buying the stock just before each uptick in the market and selling before each downtick. Similarly, the condition that H is adapted implies that the stochastic integral will not diverge when calculated as a limit of Riemann sums (Revuz & Yor 1999, Chapter IV).

🔗 United Kingdom 🔗 Education 🔗 Science

The Nuffield Science Teaching Project was a programme to develop a better approach to teaching science in British secondary schools, under the auspices of the Nuffield Foundation. Although not intended as a curriculum, it gave rise to alternative national examinations, and its use of discovery learning was influential in the 1960s and 1970s.

🔗 United States 🔗 Media 🔗 Popular Culture 🔗 Georgia (U.S. state) 🔗 United States/United States Presidents 🔗 Animals in media

The Jimmy Carter rabbit incident, sensationalized as the "killer rabbit attack" by the press, involved a swamp rabbit (Sylvilagus aquaticus) that swam toward then-U.S. President Jimmy Carter's fishing boat on April 20, 1979. The incident caught the imagination of the media after Carter's press secretary, Jody Powell, mentioned the event to a correspondent months later.

Political opponents argued that the incident was symbolic of Carter's purported weakness. According to Powell, anti-Carter political commentators went so far as to blame it for the Soviet invasion of Afghanistan and the Iran hostage crisis.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Books 🔗 Business

War Is a Racket is a speech and a 1935 short book by Smedley D. Butler, a retired United States Marine Corps Major General and two-time Medal of Honor recipient. Based on his career military experience, Butler discusses how business interests commercially benefit from warfare. He had been appointed commanding officer of the Gendarmerie during the 1915–1934 United States occupation of Haiti.

After Butler retired from the US Marine Corps in October 1931, he made a nationwide tour in the early 1930s giving his speech "War Is a Racket". The speech was so well received that he wrote a longer version as a short book published in 1935. His work was condensed in Reader's Digest as a book supplement, which helped popularize his message. In an introduction to the Reader's Digest version, Lowell Thomas, who wrote Butler’s oral autobiography, praised Butler's "moral as well as physical courage".