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Spatiotemporal Database
A spatiotemporal database is a database that manages both space and time information. Common examples include: * Tracking of moving objects, which typically can occupy only a single position at a given time. * A database of wireless communication networks, which may exist only for a short timespan within a geographic region. * An index of species in a given geographic region, where over time additional species may be introduced or existing species migrate or die out. * Historical tracking of plate tectonic activity. Spatiotemporal databases are an extension of spatial databases and temporal databases. A spatiotemporal database embodies spatial, temporal, and spatiotemporal database concepts, and captures spatial and temporal aspects of data and deals with: * geometry changing over time and/or * location of objects moving over invariant geometry (known variously as ''moving objects databases'' or real-time locating systems). Implementations Although there exist numerous relational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Database
A spatial database is a general-purpose database (usually a relational database) that has been enhanced to include spatial data that represents objects defined in a geometric space, along with tools for querying and analyzing such data. Most spatial databases allow the representation of simple geometric objects such as points, lines and polygons. Some spatial databases handle more complex structures such as 3D objects, topological coverages, linear networks, and triangulated irregular networks (TINs). While typical databases have developed to manage various numeric and character types of data, such databases require additional functionality to process spatial data types efficiently, and developers have often added ''geometry'' or ''feature'' data types. The Open Geospatial Consortium (OGC) developed the Simple Features specification (first released in 1997) and sets standards for adding spatial functionality to database systems. The '' SQL/MM Spatial'' ISO/IEC standard is a pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K-d Tree
In computer science, a ''k''-d tree (short for ''k-dimensional tree'') is a space-partitioning data structure for organizing points in a ''k''-dimensional space. ''k''-d trees are a useful data structure for several applications, such as searches involving a multidimensional search key (e.g. range searches and nearest neighbor searches) and creating point clouds. ''k''-d trees are a special case of binary space partitioning trees. Description The ''k''-d tree is a binary tree in which ''every'' node is a ''k''-dimensional point. Every non-leaf node can be thought of as implicitly generating a splitting hyperplane that divides the space into two parts, known as half-spaces. Points to the left of this hyperplane are represented by the left subtree of that node and points to the right of the hyperplane are represented by the right subtree. The hyperplane direction is chosen in the following way: every node in the tree is associated with one of the ''k'' dimensions, with the hyper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Databases
Spatial may refer to: *Dimension *Space *Three-dimensional space Three-dimensional space (also: 3D space, 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called ''parameters'') are required to determine the position (geometry), position of an element (i.e., Point (m ... See also * * {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Data And Information
Geographic data and information is defined in the ISO/TC 211 series of standards as data and information having an implicit or explicit association with a location relative to Earth (a geographic location or geographic position). It is also called geospatial data and information, georeferenced data and information, as well as geodata and geoinformation. Approximately 90% of government sourced data has a location component. Location information (known by the many names mentioned here) is stored in a geographic information system (GIS). There are also many different types of geodata, including vector files, raster files, geographic databases, web files, and multi-temporal data. Fields of study Geographic data and information are the subject of a number of overlapping fields of study, mainly: * Geocomputation * Geographic information science * Geoinformatics * Geomatics * Geovisualization This is in addition to other more specific branches, such as: * Cartography * Geodesy * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Management Systems
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spans formal techniques and practical considerations, including data modeling, efficient data representation and storage, query languages, security and privacy of sensitive data, and distributed computing issues, including supporting concurrent access and fault tolerance. A database management system (DBMS) is the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS software additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an application ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Geography
Time geography or time-space geography is an evolving transdisciplinary perspective on spatial and temporal processes and events such as social interaction, ecological interaction, social and environmental change, and biographies of individuals. Time geography "is not a subject area per se", but rather an integrative ontological framework and visual language in which space and time are basic dimensions of analysis of dynamic processes. Time geography was originally developed by human geographers, but today it is applied in multiple fields related to transportation, regional planning, geography, anthropology, time-use research, ecology, environmental science, and public health. According to Swedish geographer Bo Lenntorp: "It is a basic approach, and every researcher can connect it to theoretical considerations in her or his own way." Origins The Swedish geographer Torsten Hägerstrand created time geography in the mid-1960s based on ideas he had developed during his earlier empiric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure Mining
Structure mining or structured data mining is the process of finding and extracting useful information from semi-structured data sets. Graph mining, sequential pattern mining and molecule mining are special cases of structured data mining. Description The growth of the use of semi-structured data has created new opportunities for data mining, which has traditionally been concerned with tabular data sets, reflecting the strong association between data mining and relational databases. Much of the world's interesting and mineable data does not easily fold into relational databases, though a generation of software engineers have been trained to believe this was the only way to handle data, and data mining algorithms have generally been developed only to cope with tabular data. XML, being the most frequent way of representing semi-structured data, is able to represent both tabular data and arbitrary trees. Any particular representation of data to be exchanged between two applications i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multimedia Database
A Multimedia database (MMDB) is a collection of related for multimedia data. The multimedia data include one or more primary media data types such as text, images, graphic objects (including drawings, sketches and illustrations) animation sequences, audio and video. A Multimedia Database Management System (MMDBMS) is a framework that manages different types of data potentially represented in a wide diversity of formats on a wide array of media sources. It provides support for multimedia data types, and facilitate for creation, storage, access, query and control of a multimedia database. Contents of MMDB A Multimedia Database (MMDB) hosts one or more multimedia data types (i.e. text, images, graphic objects, audio, video, animation sequences). These data types are broadly categorized into ''three classes'': * Static media (time-independent: image and graphic object). * Dynamic media (time-dependent: audio, video and animation). * Dimensional media(3D game and computer aid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locating Engine
Real-time locating systems (RTLS), also known as real-time tracking systems, are used to automatically identify and track the location of objects or people in real time, usually within a building or other contained area. Wireless RTLS tags are attached to objects or worn by people, and in most RTLS, fixed reference points receive wireless signals from tags to determine their location. Examples of real-time locating systems include tracking automobiles through an assembly line, locating pallets of merchandise in a warehouse, or finding medical equipment in a hospital. The physical layer of RTLS technology is often radio frequency (RF) communication. Some systems use optical (usually infrared) or acoustic (usually ultrasound) technology with, or in place of, RF. RTLS tags and fixed reference points can be transmitters, receivers, or both, resulting in numerous possible technology combinations. RTLS are a form of local positioning system and do not usually refer to GPS or to mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Geographic Information System
A historical geographic information system (also written as historical GIS or HGIS) is a geographic information system that may display, store and analyze data of past geographies and track changes in time. It can be regarded as a tool for historical geography. Techniques used in HGIS * Digitization and georeferencing of historical maps: Old maps may contain valuable information about the past. By adding coordinates to such maps, they may be added as a feature layer to modern GIS data: This facilitates comparison of different map layers showing the geography at different times. The maps may be further enhanced by techniques such as rubbersheeting, which spatially warps the data to fit with more accurate modern maps. * Reconstruction of past boundaries: By creating polygons of former political entities, administrative sub-divisions and other types of borders, their evolution as well as aggregated statistics can be compared through time. * Georeferencing of historical microdata (such ... [...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] |
Temporal Database
A temporal database stores data relating to time instances. It offers temporal data types and stores information relating to past, present and future time. Temporal databases could be uni-temporal, bi-temporal or tri-temporal. More specifically the temporal aspects usually include valid time, transaction time or decision time. * Valid time is the time period during which a fact is true in the real world. * Transaction time is the time at which a fact was recorded in the database. * Decision time is the time at which the decision was made about the fact. Uni-temporal A uni-temporal database has one axis of time, either the validity range or the system time range. Bi-temporal A bi-temporal database has two axes of time: * valid time * transaction time or decision time Tri-temporal A tri-temporal database has three axes of time: * valid time * transaction time * decision time This approach introduces additional complexities. Temporal databases are in contrast to current databa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
