Huffman codingIn computer science and information theory, a Huffman code is a particular type of optimal prefix code that is commonly used for lossless data compression. The process of finding or using such a code is Huffman coding, an algorithm developed by David A. Huffman while he was a Sc.D. student at MIT, and published in the 1952 paper "A Method for the Construction of Minimum-Redundancy Codes". The output from Huffman's algorithm can be viewed as a variable-length code table for encoding a source symbol (such as a character in a file).
TitleA title is one or more words used before or after a person's name, in certain contexts. It may signify either generation, an official position, or a professional or academic qualification. In some languages, titles may be inserted between the first and last name (for example, Graf in German, Cardinal in Catholic usage (Richard Cardinal Cushing) or clerical titles such as Archbishop). Some titles are hereditary.
Entropy (information theory)In information theory, the entropy of a random variable is the average level of "information", "surprise", or "uncertainty" inherent to the variable's possible outcomes. Given a discrete random variable , which takes values in the alphabet and is distributed according to : where denotes the sum over the variable's possible values. The choice of base for , the logarithm, varies for different applications. Base 2 gives the unit of bits (or "shannons"), while base e gives "natural units" nat, and base 10 gives units of "dits", "bans", or "hartleys".
Korean mixed scriptKorean mixed script () is a form of writing the Korean language that uses a mixture of the Korean alphabet or Hangul () and Hanja (, ), the Korean name for Chinese characters. The distribution on how to write words usually follows that all native Korean words, including suffixes, particles, and honorific markers are generally written in hangul and never in hanja. Sino-Korean vocabulary or hanja-eo (), either words borrowed from Chinese or created from Sino-Korean roots, were generally always written in hanja, although very rare or complex characters were often substituted with hangul.
Korean languageKorean (South Korean: , hangugeo; North Korean: , chosŏnmal) is the native language for about 80 million people, mostly of Korean descent. It is the official and national language of both North Korea and South Korea (geographically Korea). The two countries have established standardized norms for Korean, and the differences between them are similar to those between Standard Chinese in mainland China and Taiwan, but political conflicts between the two countries have highlighted the differences between them.
Title (property)In property law, title is an intangible construct representing a bundle of rights in (to) a piece of property in which a party may own either a legal interest or equitable interest. The rights in the bundle may be separated and held by different parties. It may also refer to a formal document, such as a deed, that serves as evidence of ownership. Conveyance of the document (transfer of title to the property) may be required in order to transfer ownership in the property to another person.
Subject–object–verb word orderIn linguistic typology, a subject–object–verb (SOV) language is one in which the subject, object, and verb of a sentence always or usually appear in that order. If English were SOV, "Sam beer drank" would be an ordinary sentence, as opposed to the actual Standard English "Sam drank beer" which is subject–verb–object (SVO). The term is often loosely used for ergative languages like Adyghe and Basque that really have agents instead of subjects.
Torrens titleTorrens title is a land registration and land transfer system, in which a state creates and maintains a register of land holdings, which serves as the conclusive evidence (termed "indefeasibility") of title of the person recorded on the register as the proprietor (owner), and of all other interests recorded on the register. Ownership of land is transferred by registration of a transfer of title, instead of by the use of deeds. The Registrar provides a Certificate of Title to the new proprietor, which is merely a copy of the related folio of the register.
Jeju languageJeju (Jeju: 제줏말; Jeju RR: , or , or ), often called Jejueo or Jejuan in English-language scholarship, is a Koreanic language originally from Jeju Island, South Korea. It is not mutually intelligible with mainland Korean dialects. While it was historically considered a divergent Jeju dialect of the Korean language, it is increasingly referred to as a language. It is declining in usage, and was classified by UNESCO in 2010 as critically endangered, the highest level of language endangerment possible.
Hereditary titleHereditary titles, in a general sense, are nobility titles, positions or styles that are hereditary and thus tend or are bound to remain in particular families. Though both monarchs and nobles usually inherit their titles, the mechanisms often differ, even in the same country. The British crown has been heritable by women since the medieval era (in the absence of brothers), while the vast majority of hereditary noble titles granted by British sovereigns are not heritable by daughters.
Space–time block codeSpace–time block coding is a technique used in wireless communications to transmit multiple copies of a data stream across a number of antennas and to exploit the various received versions of the data to improve the reliability of data transfer. The fact that the transmitted signal must traverse a potentially difficult environment with scattering, reflection, refraction and so on and may then be further corrupted by thermal noise in the receiver means that some of the received copies of the data may be closer to the original signal than others.
Information theoryInformation theory is the mathematical study of the quantification, storage, and communication of information. The field was originally established by the works of Harry Nyquist and Ralph Hartley, in the 1920s, and Claude Shannon in the 1940s. The field, in applied mathematics, is at the intersection of probability theory, statistics, computer science, statistical mechanics, information engineering, and electrical engineering. A key measure in information theory is entropy.
Cross-entropyIn information theory, the cross-entropy between two probability distributions and over the same underlying set of events measures the average number of bits needed to identify an event drawn from the set if a coding scheme used for the set is optimized for an estimated probability distribution , rather than the true distribution . The cross-entropy of the distribution relative to a distribution over a given set is defined as follows: where is the expected value operator with respect to the distribution .
MIMOIn radio, multiple-input and multiple-output (MIMO) (ˈmaɪmoʊ,_ˈmiːmoʊ) is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wireless communication standards including IEEE 802.11n (Wi-Fi 4), IEEE 802.11ac (Wi-Fi 5), HSPA+ (3G), WiMAX, and Long Term Evolution (LTE). More recently, MIMO has been applied to power-line communication for three-wire installations as part of the ITU G.
Variable-length codeIn coding theory, a variable-length code is a code which maps source symbols to a variable number of bits. The equivalent concept in computer science is bit string. Variable-length codes can allow sources to be compressed and decompressed with zero error (lossless data compression) and still be read back symbol by symbol. With the right coding strategy an independent and identically-distributed source may be compressed almost arbitrarily close to its entropy.
Rényi entropyIn information theory, the Rényi entropy is a quantity that generalizes various notions of entropy, including Hartley entropy, Shannon entropy, collision entropy, and min-entropy. The Rényi entropy is named after Alfréd Rényi, who looked for the most general way to quantify information while preserving additivity for independent events. In the context of fractal dimension estimation, the Rényi entropy forms the basis of the concept of generalized dimensions. The Rényi entropy is important in ecology and statistics as index of diversity.
Entropy codingIn information theory, an entropy coding (or entropy encoding) is any lossless data compression method that attempts to approach the lower bound declared by Shannon's source coding theorem, which states that any lossless data compression method must have expected code length greater or equal to the entropy of the source. More precisely, the source coding theorem states that for any source distribution, the expected code length satisfies , where is the number of symbols in a code word, is the coding function, is the number of symbols used to make output codes and is the probability of the source symbol.
Algorithmic information theoryAlgorithmic information theory (AIT) is a branch of theoretical computer science that concerns itself with the relationship between computation and information of computably generated objects (as opposed to stochastically generated), such as strings or any other data structure. In other words, it is shown within algorithmic information theory that computational incompressibility "mimics" (except for a constant that only depends on the chosen universal programming language) the relations or inequalities found in information theory.
Cyclic codeIn coding theory, a cyclic code is a block code, where the circular shifts of each codeword gives another word that belongs to the code. They are error-correcting codes that have algebraic properties that are convenient for efficient error detection and correction. Let be a linear code over a finite field (also called Galois field) of block length . is called a cyclic code if, for every codeword from , the word in obtained by a cyclic right shift of components is again a codeword.
EntropyEntropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory.
