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Base 4
A quaternary numeral system is base-. It uses the digits 0, 1, 2 and 3 to represent any real number. Conversion from binary is straightforward. Four is the largest number within the subitizing range and one of two numbers that is both a square and a highly composite number (the other being 36), making quaternary a convenient choice for a base at this scale. Despite being twice as large, its radix economy is equal to that of binary. However, it fares no better in the localization of prime numbers (the smallest better base being the primorial base six, senary). Quaternary shares with all fixed- radix numeral systems many properties, such as the ability to represent any real number with a canonical representation (almost unique) and the characteristics of the representations of rational numbers and irrational numbers. See decimal and binary for a discussion of these properties. Relation to other positional number systems Relation to binary and hexadecimal As with the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numeral System
A numeral system (or system of numeration) is a writing system for expressing numbers; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. The same sequence of symbols may represent different numbers in different numeral systems. For example, "11" represents the number ''eleven'' in the decimal numeral system (used in common life), the number ''three'' in the binary numeral system (used in computers), and the number ''two'' in the unary numeral system (e.g. used in tallying scores). The number the numeral represents is called its value. Not all number systems can represent all numbers that are considered in the modern days; for example, Roman numerals have no zero. Ideally, a numeral system will: *Represent a useful set of numbers (e.g. all integers, or rational numbers) *Give every number represented a unique representation (or at least a standard representation) *Reflect the algebraic and arithme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexadecimal
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexadecimal uses 16 distinct symbols, most often the symbols "0"–"9" to represent values 0 to 9, and "A"–"F" (or alternatively "a"–"f") to represent values from 10 to 15. Software developers and system designers widely use hexadecimal numbers because they provide a human-friendly representation of binary-coded values. Each hexadecimal digit represents four bits (binary digits), also known as a nibble (or nybble). For example, an 8-bit byte can have values ranging from 00000000 to 11111111 in binary form, which can be conveniently represented as 00 to FF in hexadecimal. In mathematics, a subscript is typically used to specify the base. For example, the decimal value would be expressed in hexadecimal as . In programming, a number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar ( ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Code
The genetic code is the set of rules used by living cells to translate information encoded within genetic material ( DNA or RNA sequences of nucleotide triplets, or codons) into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries. The codons specify which amino acid will be added next during protein biosynthesis. With some exceptions, a three-nucleotide codon in a nucleic acid sequence specifies a single amino acid. The vast majority of genes are encoded with a single scheme (see the RNA codon table). That scheme is often referred to as the canonical or standard genetic code, or simply ''the'' genetic code, though variant codes (such as in mitochondria) exist. History Effor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilbert Curve
The Hilbert curve (also known as the Hilbert space-filling curve) is a continuous fractal space-filling curve first described by the German mathematician David Hilbert in 1891, as a variant of the space-filling Peano curves discovered by Giuseppe Peano in 1890. Because it is space-filling, its Hausdorff dimension is 2 (precisely, its image is the unit square, whose dimension is 2 in any definition of dimension; its graph is a compact set homeomorphic to the closed unit interval, with Hausdorff dimension 2). The Hilbert curve is constructed as a limit of piecewise linear curves. The length of the nth curve is \textstyle 2^n - , i.e., the length grows exponentially with n, even though each curve is contained in a square with area 1. Images File:Hilbert curve 1.svg, Hilbert curve, first order File:Hilbert curve 2.svg, Hilbert curves, first and second orders File:Hilbert curve 3.svg, Hilbert curves, first to third orders File:Hilbert curve production rules!.svg, Production rules Fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kharosthi
The Kharoṣṭhī script, also spelled Kharoshthi (Kharosthi: ), was an ancient Indo-Iranian script used by various Aryan peoples in north-western regions of the Indian subcontinent, more precisely around present-day northern Pakistan and eastern Afghanistan. It was used in Central Asia as well. An abugida, it was introduced at least by the middle of the 3rd century BCE, possibly during the 4th century BCE, and remained in use until it died out in its homeland around the 3rd century CE. It was also in use in Bactria, the Kushan Empire, Sogdia, and along the Silk Road. There is some evidence it may have survived until the 7th century in Khotan and Niya, both cities in East Turkestan. Form Kharosthi (, from right to left ''Kha-ro-ṣṭhī'') is mostly written right to left (type A). Each syllable includes the short /a/ sound by default, with other vowels being indicated by diacritic marks. Recent epigraphic evidence has shown that the order of letters in the Kharosthi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventureño Language
Ventureño is a member of the extinct Chumashan languages, a group of Native American languages previously spoken by the Chumash people along the coastal areas of Southern California from as far north as San Luis Obispo to as far south as Malibu. Ventureño was spoken from as far north as present-day Ventura to as far south as present-day Malibu and the Simi Hills, California. Dialects probably also included Castac and Alliklik.Campbell 1997:126 Ventureño is, like its sister Chumashan languages, a polysynthetic language, having larger words composed of a number of morphemes. Ventureño has separate word classes of verb, noun, and oblique adjunct; with no separate word class for adjectives or adpositions. Nouns and verbs are often heavily affixed (mostly prefixed) in Ventureño, affixing being a way to denote those meanings often conveyed by separate words in more analytic languages. Verbs play a primary role in Ventureño with utterances often composed only of a verb wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chumash People
The Chumash are a Native American people of the central and southern coastal regions of California, in portions of what is now San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties, extending from Morro Bay in the north to Malibu in the south. Their territory included three of the Channel Islands: Santa Cruz, Santa Rosa, and San Miguel; the smaller island of Anacapa was likely inhabited seasonally due to the lack of a consistent water source. Modern place names with Chumash origins include Malibu, Nipomo, Lompoc, Ojai, Pismo Beach, Point Mugu, Port Hueneme, Piru, Lake Castaic, Saticoy, Simi Valley and Somis. Archaeological research demonstrates that the Chumash people have deep roots in the Santa Barbara Channel area and lived along the southern California coast for millennia. History Prior to European contact (pre-1542) Indigenous peoples have lived along the California coast for at least 11,000 years. Sites of the Millingstone Horizon date fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chumashan Languages
Chumashan was a family of languages that were spoken on the southern California coast by Native American Chumash people, from the Coastal plains and valleys of San Luis Obispo to Malibu, neighboring inland and Transverse Ranges valleys and canyons east to bordering the San Joaquin Valley, to three adjacent Channel Islands: San Miguel, Santa Rosa, and Santa Cruz. The Chumashan languages may be, along with Yukian and perhaps languages of southern Baja such as Waikuri, one of the oldest language families established in California, before the arrival of speakers of Penutian, Uto-Aztecan, and perhaps even Hokan languages. Chumashan, Yukian, and southern Baja languages are spoken in areas with long-established populations of a distinct physical type. The population in the core Chumashan area has been stable for the past 10,000 years. However, the attested range of Chumashan is recent (within a couple thousand years). There is internal evidence that Obispeño replaced a Hokan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplication Table
In mathematics, a multiplication table (sometimes, less formally, a times table) is a mathematical table used to define a multiplication operation for an algebraic system. The decimal multiplication table was traditionally taught as an essential part of elementary arithmetic around the world, as it lays the foundation for arithmetic operations with base-ten numbers. Many educators believe it is necessary to memorize the table up to 9 × 9. History In pre-modern time The oldest known multiplication tables were used by the Babylonians about 4000 years ago. However, they used a base of 60. The oldest known tables using a base of 10 are the Chinese decimal multiplication table on bamboo strips dating to about 305 BC, during China's Warring States period. The multiplication table is sometimes attributed to the ancient Greek mathematician Pythagoras (570–495 BC). It is also called the Table of Pythagoras in many languages (for example French, Italian and Russian), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms (usually in a chosen programming language, commonly referred to as coding). The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. The purpose of programming is to find a sequence of instructions that will automate the performance of a task (which can be as complex as an operating system) on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the application domain, specialized algorit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
