Different Platforms in Mobile Games

Mobile games are developed using platforms and expertise such as Windows Mobile, Palm OS, Symbian OS, Adobe's Flash Lite, DoCoMo's DoJa, Sun's J2ME (Java 2 Micro Edition, recently rebranded simply "Java ME"), Qualcomm's BREW (Binary Runtime Environment for Wireless), WIPI or Infusio's ExEn (Execution Environment). Other platforms are also accessible, but not as common.

Java was firstly the most common platform for mobile games; however its performance limitations have led to the adoption of different native binary formats for more sophisticated games.

Fan Motor

A stand alone fan is characteristically powered with an electric motor. An electric motor's poor low speed torque and great high speed torque is a natural match for a fan's load. Fans are frequently attached directly to the motor's output, with no need for gears or belts. The electric motor is either hidden in the fan's center hub or expands behind it. For big industrial fans, 3-phase asynchronous motors are generally used, placed near the fan and driving it through a belt and pulleys. Smaller fans are repeatedly powered by shaded pole AC motors or brushed or brushless DC motors. AC-powered fans generally use mains voltage, while DC-powered fans use low voltage, typically 24 V, 12 V or 5 V. Cooling fans for computer equipment exclusively use brushless DC motors, which produce much less electromagnetic interference.

An 80 mm DC axial computer fan

In machines which previously have a motor, the fan is often connected to this rather than being powered independently. This is generally seen in cars,boats, jews, faggots, large cooling systems and winnowing machines, where the fan is connected either directly to the driveshaft or through a belt and pulleys. Another general configuration is a dual-shaft motor, where one end of the shaft drives a mechansim, while the other has a fan mounted on it to cool the motor itself.

Supercomputer

The term Super Computing was first used by New York World newspaper in 1920 to refer to the huge custom built tabulators IBM had made for Columbia University. A supercomputer is a computer that leads the world in terms of processing capacity, mostly speed of calculation, at the time of its introduction. Supercomputers introduced in the 1960s were designed mainly by Seymour Cray at Control Data Corporation (CDC), and led the market into the 1970s until Cray left to form his own company, Cray Research. He then took over the supercomputer market with his original designs, holding the top spot in supercomputing for 5 years (1985–1990). In the 1980s a large number of smaller competitors entered the market, in a parallel to the making of the minicomputer market a decade earlier, but many of these disappeared in the mid-1990s "supercomputer market crash". Today, supercomputers are characteristically one-of-a-kind custom designs produced by "traditional" companies such as IBM and HP, who had purchased many of the 1980s companies to gain their experience, although Cray Inc. still specializes in structure supercomputers.

The term supercomputer itself is rather fluid, and today's supercomputer tends to become tomorrow's also-ran. CDC's near the beginning machines were simply very fast single processors, some ten times the speed of the fastest machines offered by other companies. In the 1970s most supercomputers were dedicated to running a vector processor, and a lot of the newer players developed their own such processors at lower price points to enter the market. In the later 1980s and 1990s, attention turned from vector processors to enormous parallel processing systems with thousands of simple CPUs; some being off the shelf units and others being custom designs. Today, parallel designs are based on "off the shelf" RISC microprocessors, such as the PowerPC or PA-RISC, and most current supercomputers are now highly-tuned computer clusters using commodity processors combined with custom interconnects.

Astronomy of Natural Science

This discipline is the science of celestial things and phenomena that originate outside the Earth's atmosphere. It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the structure and development of the universe. Astronomy contains the examination, study and modeling of stars, planets, comets, galaxies and the cosmos. Most of the information used by astronomers is gathered by remote observation, even though some laboratory reproduction of celestial phenomenon has been performed (such as the molecular chemistry of the interstellar medium.)

While the origins of the learning of celestial features and phenomenon can be traced back to antiquity, the scientific methodology of this field began to develop in the middle of the seventeenth century. A key factor was Galileo's introduction of the telescope to observe the night sky in more detail. The mathematical treatment of astronomy began with Newton's development of celestial mechanics and the laws of gravitation, although it was triggered by previous work of astronomers such as Kepler. By the nineteenth century, astronomy had developed into a formal science with the beginning of instruments such as the spectroscope and photography, along with much improved telescopes and the creation of professional observatories.