A* search algorithm

In computer science, A* (pronounced as "A star" ( listen)) is a computer algorithm that is widely used in pathfinding and graph traversal, the process of plotting an efficiently traversable path between multiple points, called nodes. Noted for its performance and accuracy, it enjoys widespread use. However, in practical travel-routing systems, it is generally outperformed by algorithms which can pre-process the graph to attain better performance, although other work has found A* to be superior to other approaches.

Peter Hart, Nils Nilsson and Bertram Raphael of Stanford Research Institute (now SRI International) first described the algorithm in 1968. It is an extension of Edsger Dijkstra's 1959 algorithm. A* achieves better performance by using heuristics to guide its search.

History

In 1968, AI researcher Nils Nilsson was trying to improve the path planning done by Shakey the Robot, a prototype robot that could navigate through a room containing obstacles. This path-finding algorithm, that Nilsson called A1, was a faster version of the then best known method, Dijkstra's algorithm, for finding shortest paths in graphs. Bertram Raphael suggested some significant improvements upon this algorithm, calling the revised version A2. Then Peter E. Hart introduced an argument that established A2, with only minor changes, to be the best possible algorithm for finding shortest paths. Hart, Nilsson and Raphael then jointly developed a proof that the revised A2 algorithm was optimal for finding shortest paths under certain well-defined conditions.

Prince

A prince is a male ruler, monarch, or member of a monarch's or former monarch's family. Prince is also a hereditary title in the nobility of some European states. The feminine equivalent is a princess. The English word derives, via the French word prince, from the Latin noun princeps, from primus (first) + capio (to seize), meaning "the chief, most distinguished, ruler, prince".

Historical background

The Latin word prīnceps (older Latin *prīsmo-kaps, literally "the one who takes the first [place/position]"), became the usual title of the informal leader of the Roman senate some centuries before the transition to empire, the princeps senatus.

Emperor Augustus established the formal position of monarch on the basis of principate, not dominion. He also tasked his grandsons as summer rulers of the city when most of the government were on holiday in the country or attending religious rituals, and, for that task, granted them the title of princeps.

The title has generic and substantive meanings:

Star

A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.

For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space. Once the hydrogen in the core of a star is nearly exhausted, almost all naturally occurring elements heavier than helium are created by stellar nucleosynthesis during the star's lifetime and, for some stars, by supernova nucleosynthesis when it explodes. Near the end of its life, a star can also contain degenerate matter. Astronomers can determine the mass, age, metallicity (chemical composition), and many other properties of a star by observing its motion through space, luminosity, and spectrum respectively. The total mass of a star is the principal determinant of its evolution and eventual fate. Other characteristics of a star, including diameter and temperature, change over its life, while the star's environment affects its rotation and movement. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung–Russell diagram (H–R diagram), allows the age and evolutionary state of a star to be determined.

Uta no Prince-sama

Uta no Prince-sama (Japanese: うたの☆プリンスさまっ♪, Hepburn: Uta no☆Purinsu-sama♪, lit. "Princes of Song") is a Japanese visual novel series published by Broccoli. It is a popular game franchise targeted towards the female audience. Being a well known series in Japan, the game has been adapted into a manga and anime series along with various franchise-related merchandise such as drama CDs, music CDs, and fanbooks.

Gameplay

Uta no☆Prince-sama♪ is a comedy and romance visual novel in which the player assumes the character of Haruka Nanami. Uta no☆Prince-sama♪ follows a branching plot line with multiple endings; depending on the decisions that the player makes during the game, the plot will progress in a specific direction.

There are seven main plot lines that the player will have the chance to experience, three which are initially available (four in All Star). Throughout gameplay, the player is given multiple options to choose from, and text progression pauses at these points until a choice is made. To view all plot lines in their entirety, the player must replay the game multiple times and make different choices to change the plot progression.

Idolmaster: Xenoglossia

Idolmaster: Xenoglossia (アイドルマスター XENOGLOSSIA, Aidorumasutā: Xenoglossia) is a 26-episode anime television series by Sunrise, based on the Namco Bandai Games series The Idolmaster. It aired between April 4 and September 24, 2007 on Kansai TV and various other UHF television stations. The series was also broadcast over the Internet on the Japanese website @nifty. The series has been licensed by Sentai Filmworks in North America. The word Xenoglossia in the title is a term taken from Greek for using a language (talking, reading or writing) that is completely unknown to the user.

Plot

Idolmaster: Xenoglossia centers around mecha and re-imagines the ten prospective idols from The Idolmaster as fighter pilots of those robots, with eight of them also posing as students. The large robots are called Immortal Defender of Legatee (IDOL) and their pilots are called Idolmasters. IDOL pilots have to be girls, and they have to be chosen by the IDOL itself. The Moon was destroyed 107 years prior to the beginning of the story in an event called Lost Artemis. This event caused numerous fragments to fall onto the Earth, which killed about one quarter of the Earth's total population. The remaining fragments of the Moon which orbit around the Earth are called Kompeito or Confeito. Once a fragment falls onto Earth, it is called a Drop. If the Drop is big, resulting in a moderate threat to the Earth, then it will be called Mint Drop or Lemon Drop according to sizes. Humans found a special silicon on Earth, probably from fallen Drops, and started research to turn that silicon into IDOL cores, of which there are five. The IDOLs are named after Lunar maria.