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Geohash-36
The Geohash-36 geocode is an opensource compression algorithm for world coordinate data. It was developed as a variation of the OpenPostcode format developed as a candidate geolocation postcode for the Republic of Ireland. It is calculated differently and uses a more concise base 36 representation rather than other geocodes that adopted base 32. Despite the name, there are no algorithmic (not use Z-order curve) or typological relationship with Geohash. It is a publicity strategy to relate to a popular geocode of base 32. The encode/decode functions are not mathematically-similar to Geohash functions. Coding Method Designed for URLs and electronic storage and communication rather than human memory and conversation, it is case-sensitive, using a 36 character alphabet: "23456789bBCdDFgGhHjJKlLMnNPqQrRtTVWX". Character Conversion: Characters are chosen to avoid vowels, vowel-like numbers, character confusion, and to use lowercase characters which are generally distinct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Geodesic-geocoding Systems
A discrete global grid (DGG) is a tessellation, mosaic that covers the entire Earth's surface. Mathematically it is a space partitioning: it consists of a set of non-empty regions that form a Partition of a set, partition of the Earth's surface. In a usual grid-modeling strategy, to simplify position calculations, each region is represented by a point, abstracting the grid as a set of region-points. Each region or region-point in the grid is called a cell. When each cell of a grid is subject to a Recursion, recursive partition, resulting in a "series of discrete global grids with progressively finer resolution", forming a hierarchical grid, it is called a hierarchical DGG (sometimes "global hierarchical tessellation" or "DGG system"). Discrete global grids are used as the geometric basis for the building of geospatial data structures. Each cell is Entity–relationship model, related with data objects or values, or (in the hierarchical case) may be associated with other cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geohash
Geohash is a public domain geocode system invented in 2008 by Gustavo NiemeyerEvidences at the Wayback Machine: labix.org in 2008, the G. Niemeyer's blog announcing Geohash *an article about Geohash witnessing and citing G. Niemeyer works, before 2012 G. Niemeyer's post at forums.geocaching.com announcing Geohash in Feb. 2008 which encodes a geographic location into a short string of letters and digits. Similar ideas were introduced by G.M. Morton in 1966.G. M. Morton (196''"A Computer Oriented Geodetic Data Base and a New Technique in File Sequencing"''. Report in IBM Canada. It is a hierarchical spatial data structure which subdivides space into buckets of grid shape, which is one of the many applications of what is known as a Z-order curve, and generally space-filling curves. Geohashes offer properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision). Geohashing guarantees th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vowel
A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness and also in quantity (length). They are usually voiced and are closely involved in prosodic variation such as tone, intonation and stress. The word ''vowel'' comes from the Latin word , meaning "vocal" (i.e. relating to the voice). In English, the word ''vowel'' is commonly used to refer both to vowel sounds and to the written symbols that represent them (a, e, i, o, u, and sometimes y). Definition There are two complementary definitions of vowel, one phonetic and the other phonological. *In the phonetic definition, a vowel is a sound, such as the English "ah" or "oh" , produced with an open vocal tract; it is median (the air escapes along the middle of the tongue), oral (at least some of the airflow must escape through the mouth), frictionless and continuant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shard London Bridge
The Shard, also referred to as the Shard of Glass, Shard London Bridge, and formerly London Bridge Tower, is a 72-storey skyscraper, designed by the Italian architect Renzo Piano, in Southwark, London, that forms part of The Shard Quarter development. Standing high, The Shard is the tallest building in the United Kingdom, and the seventh-tallest building in Europe. It is also the second-tallest free-standing structure in the United Kingdom, after the concrete tower of the Emley Moor transmitting station. It replaced Southwark Towers, a 24-storey office block built on the site in 1975. The Shard's construction began in March 2009; it was topped out on 30 March 2012 and inaugurated on 5 July 2012. Practical completion was achieved in November 2012. The tower's privately operated observation deck, The View from The Shard, was opened to the public on 1 February 2013. The glass-clad pyramidal tower has 72 habitable floors, with a viewing gallery and open-air observation deck on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statue Of Liberty
The Statue of Liberty (''Liberty Enlightening the World''; French: ''La Liberté éclairant le monde'') is a List of colossal sculpture in situ, colossal neoclassical sculpture on Liberty Island in New York Harbor in New York City, in the United States. The copper statue, a gift from the people of France, was designed by French sculptor Frédéric Auguste Bartholdi and its metal framework was built by Gustave Eiffel. The statue was dedicated on October 28, 1886. The statue is a figure of Libertas, a robed Roman liberty goddess. She holds a torch above her head with her right hand, and in her left hand carries a ''tabula ansata'' inscribed JULY IV MDCCLXXVI (July 4, 1776 in Roman numerals), the date of the United States Declaration of Independence, U.S. Declaration of Independence. A broken shackle and chain lie at her feet as she walks forward, commemorating the recent national abolition of slavery. After its dedication, the statue became an icon of freedom and of the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decimal Data Type
Some programming languages (or compilers for them) provide a built-in (primitive) or library decimal data type to represent non-repeating decimal fractions like 0.3 and -1.17 without rounding, and to do arithmetic on them. Examples are the decimal.Decimal type of Python, and analogous types provided by other languages. Rationale Fractional numbers are supported on most programming languages as floating-point numbers or fixed-point numbers. However, such representations typically restrict the denominator to a power of two. Most decimal fractions (or most fractions in general) cannot be represented exactly as a fraction with a denominator that is a power of two. For example, the simple decimal fraction 0.3 (3/10) might be represented as 5404319552844595/18014398509481984 (0.299999999999999988897769...). This inexactness causes many problems that are familiar to experienced programmers. For example, the expression 0.1 * 7 0.7 might counterintuitively evaluate to false in some system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modulo Operator
In computing, the modulo operation returns the remainder or signed remainder of a division, after one number is divided by another (called the '' modulus'' of the operation). Given two positive numbers and , modulo (often abbreviated as ) is the remainder of the Euclidean division of by , where is the dividend and is the divisor. For example, the expression "5 mod 2" would evaluate to 1, because 5 divided by 2 has a quotient of 2 and a remainder of 1, while "9 mod 3" would evaluate to 0, because 9 divided by 3 has a quotient of 3 and a remainder of 0; there is nothing to subtract from 9 after multiplying 3 times 3. Although typically performed with and both being integers, many computing systems now allow other types of numeric operands. The range of values for an integer modulo operation of is 0 to inclusive ( mod 1 is always 0; is undefined, possibly resulting in a division by zero error in some programming languages). See Modular arithmetic for an older and related c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Checksum
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity. The procedure which generates this checksum is called a checksum function or checksum algorithm. Depending on its design goals, a good checksum algorithm usually outputs a significantly different value, even for small changes made to the input. This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted. Checksum functions are related to hash functions, fingerprints, randomization functions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge Cases
An edge case is a problem or situation that occurs only at an extreme (maximum or minimum) operating parameter. For example, a stereo speaker might noticeably distort audio when played at maximum volume, even in the absence of any other extreme setting or condition. An edge case can be expected or unexpected. In engineering, the process of planning for and gracefully addressing edge cases can be a significant task, and yet this task may be overlooked or underestimated. Non-trivial edge cases can result in the failure of an object that is being engineered. They may not have been foreseen during the design phase, and they may not have been thought possible during normal use of the object. For this reason, attempts to formalize good engineering standards often include information about edge cases. Software engineering In programming, an edge case typically involves input values that require special handling in an algorithm behind a computer program. As a measure for validating th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocoding
Address geocoding, or simply geocoding, is the process of taking a text-based description of a location, such as an address or the name of a place, and returning geographic coordinates, frequently latitude/longitude pair, to identify a location on the Earth's surface. Reverse geocoding, on the other hand, converts geographic coordinates to a description of a location, usually the name of a place or an addressable location. Geocoding relies on a computer representation of address points, the street / road network, together with postal and administrative boundaries. * Geocode (''verb''): provide geographical coordinates corresponding to (a location). * Geocode (''noun''): is a code that represents a geographic entity (location or object).Sometimes the term can be used in a broader sense: the characterization of a neighborhood, locality, etc., according to such demographic features as ethnic composition or the average income or educational level of its inhabitants, especially as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opensource
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized software development model that encourages open collaboration. A main principle of open-source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open-source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open-source appropriate technology, and open-source drug discovery. Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase ''open source'' became widely adopted, developers and producers have used a variety of other terms. ''Open source'' gaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z-order Curve
In mathematical analysis and computer science, functions which are Z-order, Lebesgue curve, Morton space-filling curve, Morton order or Morton code map multidimensional data to one dimension while preserving locality of the data points. It is named in France after Henri Lebesgue, who studied it in 1904, and named in US after Guy Macdonald Morton, who first applied the order to file sequencing in 1966. The z-value of a point in multidimensions is simply calculated by interleaving the binary representations of its coordinate values. Once the data are sorted into this ordering, any one-dimensional data structure can be used such as binary search trees, B-trees, skip lists or (with low significant bits truncated) hash tables. The resulting ordering can equivalently be described as the order one would get from a depth-first traversal of a quadtree or octree. Coordinate values The figure below shows the Z-values for the two dimensional case with integer coordinates 0 ≤&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
