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Tetromino Tetracube Packing
A tetromino is a geometric shape composed of four squares, connected orthogonally (i.e. at the edges and not the corners). Tetrominoes, like dominoes and pentominoes, are a particular type of polyomino. The corresponding polycube, called a tetracube, is a geometric shape composed of four cubes connected orthogonally. A popular use of tetrominoes is in the video game ''Tetris'' created by the Soviet game designer Alexey Pajitnov, which refers to them as tetriminos. The tetrominoes used in the game are specifically the one-sided tetrominoes. The tetrominoes Free tetrominoes Polyominos are formed by joining unit squares along their edges. A free polyomino is a polyomino considered up to congruence. That is, two free polyominos are the same if there is a combination of translations, rotations, and reflections that turns one into the other. A free tetromino is a free polyomino made from four squares. There are five free tetrominoes. The free tetrominoes have the following symmetry: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
All 5 Free Tetrominoes
All or ALL may refer to: Language * All, an indefinite pronoun in English * All, one of the English determiners * Allar language (ISO 639-3 code) * Allative case (abbreviated ALL) Music * All (band), an American punk rock band * ''All'' (All album), 1999 * ''All'' (Descendents album) or the title song, 1987 * ''All'' (Horace Silver album) or the title song, 1972 * ''All'' (Yann Tiersen album), 2019 * "All" (song), by Patricia Bredin, representing the UK at Eurovision 1957 * "All (I Ever Want)", a song by Alexander Klaws, 2005 * "All", a song by Collective Soul from ''Hints Allegations and Things Left Unsaid'', 1994 Science and mathematics * ALL (complexity), the class of all decision problems in computability and complexity theory * Acute lymphoblastic leukemia * Anterolateral ligament Sports * American Lacrosse League * Arena Lacrosse League, Canada * Australian Lacrosse League Other uses * All, Missouri, a community in the United States * All, a brand of Sun Products * A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (mathematics)
In mathematics, a reflection (also spelled reflexion) is a mapping from a Euclidean space to itself that is an isometry with a hyperplane as a set of fixed points; this set is called the axis (in dimension 2) or plane (in dimension 3) of reflection. The image of a figure by a reflection is its mirror image in the axis or plane of reflection. For example the mirror image of the small Latin letter p for a reflection with respect to a vertical axis would look like q. Its image by reflection in a horizontal axis would look like b. A reflection is an involution: when applied twice in succession, every point returns to its original location, and every geometrical object is restored to its original state. The term ''reflection'' is sometimes used for a larger class of mappings from a Euclidean space to itself, namely the non-identity isometries that are involutions. Such isometries have a set of fixed points (the "mirror") that is an affine subspace, but is possibly smaller than a hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vadim Gerasimov
Vadim Viktorovich Gerasimov (russian: Вадим Викторович Герасимов, born 15 June 1969) is an engineer at Google. From 1994 to 2003, Vadim worked and studied at the MIT Media Lab. Vadim earned a BS/MS in applied mathematics from Moscow State University in 1992 and a Ph.D. from MIT in 2003. At age 16 he was one of the original co-developers of the famous video game ''Tetris'': he ported Alexey Pajitnov Alexey Leonidovich Pajitnov. (born 16 April 1955) is a Russian-born American computer engineer and video game designer. He is best-known for designing and developing ''Tetris'' in 1984 while working at the Dorodnitsyn Computing Centre under the A ...'s original game to the IBM PC architecture and the two later added features to the game. (Accessed August 15, 2006) References |
Pentomino
Derived from the Greek word for ' 5', and "domino", a pentomino (or 5-omino) is a polyomino of order 5, that is, a polygon in the plane made of 5 equal-sized squares connected edge-to-edge. When rotations and reflections are not considered to be distinct shapes, there are 12 different '' free'' pentominoes. When reflections are considered distinct, there are 18 '' one-sided'' pentominoes. When rotations are also considered distinct, there are 63 ''fixed'' pentominoes. Pentomino tiling puzzles and games are popular in recreational mathematics. Usually, video games such as ''Tetris'' imitations and ''Rampart'' consider mirror reflections to be distinct, and thus use the full set of 18 one-sided pentominoes. Each of the twelve pentominoes satisfies the Conway criterion; hence every pentomino is capable of tiling the plane. Each chiral pentomino can tile the plane without being reflected. History The earliest puzzle containing a complete set of pentominoes appeared in Henry D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soma Cube
The Soma cube is a solid dissection puzzle invented by Danish polymath Piet Hein in 1933 during a lecture on quantum mechanics conducted by Werner Heisenberg. Seven pieces made out of unit cubes must be assembled into a 3×3×3 cube. The pieces can also be used to make a variety of other 3D shapes. The pieces of the Soma cube consist of all possible combinations of three or four unit cubes, joined at their faces, such that at least one inside corner is formed. There is one combination of three cubes that satisfies this condition, and six combinations of four cubes that satisfy this condition, of which two are mirror images of each other (see Chirality). Thus, 3 + (6 × 4) is 27, which is exactly the number of cells in a 3×3×3 cube. The Soma cube was popularized by Martin Gardner in the September 1958 Mathematical Games column in ''Scientific American.'' The book '' Winning Ways for your Mathematical Plays'' also contains a detailed analysis of the Soma cube problem. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetromino Tetracube Packing
A tetromino is a geometric shape composed of four squares, connected orthogonally (i.e. at the edges and not the corners). Tetrominoes, like dominoes and pentominoes, are a particular type of polyomino. The corresponding polycube, called a tetracube, is a geometric shape composed of four cubes connected orthogonally. A popular use of tetrominoes is in the video game ''Tetris'' created by the Soviet game designer Alexey Pajitnov, which refers to them as tetriminos. The tetrominoes used in the game are specifically the one-sided tetrominoes. The tetrominoes Free tetrominoes Polyominos are formed by joining unit squares along their edges. A free polyomino is a polyomino considered up to congruence. That is, two free polyominos are the same if there is a combination of translations, rotations, and reflections that turns one into the other. A free tetromino is a free polyomino made from four squares. There are five free tetrominoes. The free tetrominoes have the following symmetry: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tromino
A tromino or triomino is a polyomino of order 3, that is, a polygon in the plane made of three equal-sized squares connected edge-to-edge. Symmetry and enumeration When rotations and reflections are not considered to be distinct shapes, there are only two different ''free'' trominoes: "I" and "L" (the "L" shape is also called "V"). Since both free trominoes have reflection symmetry, they are also the only two ''one-sided'' trominoes (trominoes with reflections considered distinct). When rotations are also considered distinct, there are six ''fixed'' trominoes: two I and four L shapes. They can be obtained by rotating the above forms by 90°, 180° and 270°. Rep-tiling and Golomb's tromino theorem Both types of tromino can be dissected into ''n''2 smaller trominos of the same type, for any integer ''n'' > 1. That is, they are rep-tiles. Continuing this dissection recursively leads to a tiling of the plane, which in many cases is an aperiodic tiling. In this context, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex cross-sections; and to work materials that are brittle, because the material encounters only compressive and shear stresses. It also creates excellent surface finish and gives considerable freedom of form in the design process. Drawing is a similar process, using the tensile strength of the material to pull it through the die. It limits the amount of change that can be performed in one step, so it is limited to simpler shapes, and multiple stages are usually needed. Drawing is the main way to produce wire. Metal bars and tubes are also often drawn. Extrusion may be continuous (theoretically producing indefinitely long material) or semi-continuous (producing many pieces). It can be done with hot or cold material. Commonly extruded materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solomon W
Solomon (; , ),, ; ar, سُلَيْمَان, ', , ; el, Σολομών, ; la, Salomon also called Jedidiah ( Hebrew: , Modern: , Tiberian: ''Yăḏīḏăyāh'', "beloved of Yah"), was a monarch of ancient Israel and the son and successor of David, according to the Hebrew Bible and the Old Testament. He is described as having been the penultimate ruler of an amalgamated Israel and Judah. The hypothesized dates of Solomon's reign are 970–931 BCE. After his death, his son and successor Rehoboam would adopt harsh policy towards the northern tribes, eventually leading to the splitting of the Israelites between the Kingdom of Israel in the north and the Kingdom of Judah in the south. Following the split, his patrilineal descendants ruled over Judah alone. The Bible says Solomon built the First Temple in Jerusalem, dedicating the temple to Yahweh, or God in Judaism. Solomon is portrayed as wealthy, wise and powerful, and as one of the 48 Jewish prophets. He is also the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domino
Dominoes is a family of tile-based games played with gaming pieces, commonly known as dominoes. Each domino is a rectangular tile, usually with a line dividing its face into two square ''ends''. Each end is marked with a number of spots (also called '' pips'' or ''dots'') or is blank. The backs of the tiles in a set are indistinguishable, either blank or having some common design. The gaming pieces make up a domino set, sometimes called a ''deck'' or ''pack''. The traditional European domino set consists of 28 tiles, also known as pieces, bones, rocks, stones, men, cards or just dominoes, featuring all combinations of spot counts between zero and six. A domino set is a generic gaming device, similar to playing cards or dice, in that a variety of games can be played with a set. Another form of entertainment using domino pieces is the practice of domino toppling. The earliest mention of dominoes is from Song dynasty China found in the text ''Former Events in Wulin'' by Zhou Mi (1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine. Dia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefix
A prefix is an affix which is placed before the Word stem, stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy''. Particularly in the study of languages, a prefix is also called a preformative, because it alters the form of the words to which it is affixed. Prefixes, like other affixes, can be either inflectional, creating a new form of the word with the same basic meaning and same part of speech, lexical category (but playing a different role in the sentence), or Morphological derivation, derivational, creating a new word with a new semantics, semantic meaning and sometimes also a different Part of speech, lexical category. Prefixes, like all other affixes, are usually Bound and unbound morphemes, bound morphemes. In English language, English, there are no inflectional prefixes; English uses suffixes instead for that purpose. The word ''prefix'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
