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Estimated Time Of Arrival
The estimated time of arrival (ETA) is the time when a ship, vehicle, aircraft, cargo, emergency service, or person is expected to arrive at a certain place. Overview One of the more common uses of the phrase is in public transportation where the movements of trains, buses, airplanes and the like can be used to generate estimated times of arrival depending on either a static timetable or through measurements on traffic intensity. In this respect, the phrase or its abbreviation is often paired with its complement, estimated time of departure (ETD), to indicate the expected start time of a particular journey. This information is often conveyed to a passenger information system as part of the core functionality of intelligent transportation systems. For example, a certain flight may have a calculated ETA based on the speed by which it has covered the distance traveled so far. The remaining distance is divided by the speed previously measured to roughly estimate the arrival time. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to world population growth. Ship transport is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a ship-rigged sailing ship with three or more masts, each of which is square-rigged. As of 2016, there were more than 49,000 merchant ships, totaling almost 1.8 billion dead weight tons. Of these 28% were oil tankers, 43% were bulk carriers, and 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed
In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is not the same as velocity. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or, in the US and the UK, miles per hour (mph). For air and marine travel, the knot is commonly used. The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in a vacuum ''c'' = metres per seco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as a fourth dimension, along with three spatial dimensions. Time has long been an important subject of study in religion, philosophy, and science, but defining it in a manner applicable to all fields without circularity has consistently eluded scholars. Nevertheless, diverse fields such as business, industry, sports, the sciences, and the performing arts all incorporate some notion of time into their respective measuring systems. 108 pages. Time in physics is operationally defined as "what a clock reads". The physical nature of time is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Destination Dispatch
Destination dispatch is an optimization technique used for multi-elevator installations, in which groups passengers heading to the same destinations use the same elevators, thereby reducing waiting and travel times. Comparatively, the traditional approach is where all passengers wishing to ascend or descend enter any available lift and then request their destination. Using destination dispatch, passengers request travel to a particular floor using a keypad, touch screen, or proximity card A proximity card or prox card also known as a key card or keycard is a contactless smart card which can be read without inserting it into a reader device, as required by earlier magnetic stripe cards such as credit cards and contact type sma ... room-key prior in the lobby and are immediately directed to an appropriate elevator car. Algorithms Based on information about the trips that passengers wish to make, the controller will dynamically allocate individuals to elevators to avoid exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevator
An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack. In agriculture and manufacturing, an elevator is any type of conveyor device used to lift materials in a continuous stream into bins or silos. Several types exist, such as the chain and bucket elevator, grain auger screw conveyor using the principle of Archimedes' screw, or the chain and paddles or forks of hay elevators. Languages other than English, such as Japanese, may refer to elevators by loanwords based on either ''elevator'' or ''lift''. Due to wheelchair access laws, elevators are often a legal requirement in new multistory buildings, especi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airport Gate
A gate is an area in an airport terminal that controls access to a passenger aircraft. While the exact specifications vary from airport to airport and country to country, most gates consist of a seated waiting area, a counter and a doorway leading to the aircraft. A gate adjacent to the stand where the aircraft is parked may be a ''contact gate'', providing access by way of a jet bridge, or a ''ground-loaded gate'', providing a path for passengers to leave the building to board via mobile stairs or airstairs built into the aircraft itself. A ''remote gate'' serves an aircraft stand further away, providing access to ground transportation to move passengers between the gate and the stand, where they board via stairs. Each gate typically corresponds to one parking stand on the airport's apron. A gate that provides access to multiple stands may have separate, designated doorways – sometimes termed ''sub-gates'' – for each stand. Commercial airport stands have airside components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIAA
The American Institute of Aeronautics and Astronautics (AIAA) is a professional society for the field of aerospace engineering. The AIAA is the U.S. representative on the International Astronautical Federation and the International Council of the Aeronautical Sciences. In 2015, it had more than 30,000 members among aerospace professionals worldwide (a majority are American and/or live in the United States). History The AIAA was founded in 1963 from the merger of two earlier societies: the American Rocket Society (ARS), founded in 1930 as the American Interplanetary Society (AIS), and the Institute of the Aerospace Sciences (IAS), founded in 1932 as the Institute of the Aeronautical Sciences. Paul Johnston was the first executive director of the organization. Jim Harford took his seat after 18 months. The newly-formed structure gathered 47 technical committees and one broad technical publication, the ''AIAA Journal''. The ''AIAA Student Journal'' was also launched in 1963. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Traffic Control
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions, organize and expedite the flow of air traffic, and provide information and other support for pilots. Air traffic controllers monitor the location of aircraft in their assigned airspace by radar and communicate with the pilots by radio. To prevent collisions, ATC enforces Separation (air traffic control), traffic separation rules, which ensure each aircraft maintains a minimum amount of empty space around it at all times. In many countries, ATC provides services to all private, military, and commercial aircraft operating within its airspace. Depending on the type of flight and the class of airspace, ATC may issue ''instructions'' that pilots are required to obey, or ''advis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backronym
A backronym is an acronym formed from an already existing word by expanding its letters into the words of a phrase. Backronyms may be invented with either serious or humorous intent, or they may be a type of false etymology or folk etymology. The word is a portmanteau of ''back'' and ''acronym''. An acronym is a word derived from the initial letters of the words of a phrase, such as ''radar'' from "''ra''dio ''d''etection ''a''nd ''r''anging". By contrast, a backronym is "an acronym deliberately formed from a phrase whose initial letters spell out a particular word or words, either to create a memorable name or as a fanciful explanation of a word's origin." Many fictional espionage organizations are backronyms, such as SPECTRE (''sp''ecial ''e''xecutive for ''c''ounterintelligence, ''t''errorism, ''r''evenge and ''e''xtortion) from the James Bond franchise. For example, the Amber Alert missing-child program was named after Amber Hagerman, a nine-year-old girl who was abduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program in its human-readable form is called source code. Source code needs another computer program to execute because computers can only execute their native machine instructions. Therefore, source code may be translated to machine instructions using the language's compiler. (Assembly language programs are translated using an assembler.) The resulting file is called an executable. Alternatively, source code may execute within the language's interpreter. If the executable is requested for execution, then the operating system loads it into memory and starts a process. The central processing unit will soon switch to this process so it can fetch, decode, and then execute each machine instruction. If the source code is requested for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphor
A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared with other types of figurative language, such as antithesis, hyperbole, metonymy, and simile. One of the most commonly cited examples of a metaphor in English literature comes from the " All the world's a stage" monologue from '' As You Like It'': All the world's a stage, And all the men and women merely players; They have their exits and their entrances And one man in his time plays many parts, His Acts being seven ages. At first, the infant... :—William Shakespeare, '' As You Like It'', 2/7 This quotation expresses a metaphor because the world is not literally a stage, and most humans are not literally actors and actresses playing roles. By asserting that the world is a stage, Shakespeare uses points of comparison between the world a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance
Distance is a numerical or occasionally qualitative measurement of how far apart objects or points are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria (e.g. "two counties over"). Since spatial cognition is a rich source of conceptual metaphors in human thought, the term is also frequently used metaphorically to mean a measurement of the amount of difference between two similar objects (such as statistical distance between probability distributions or edit distance between strings of text) or a degree of separation (as exemplified by distance between people in a social network). Most such notions of distance, both physical and metaphorical, are formalized in mathematics using the notion of a metric space. In the social sciences, distance can refer to a qualitative measurement of separation, such as social distance or psychological distance. Distances in physics and geometry The distance between physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
