| 释义 |
semaphore
sem·a·phore S0248400 (sĕm′ə-fôr′)n.1. A visual signaling apparatus with flags, lights, or mechanically moving arms, as one used on a railroad.2. A visual system for sending information by means of two flags that are held one in each hand, using an alphabetic code based on the position of the signaler's arms.tr. & intr.v. sem·a·phored, sem·a·phor·ing, sem·a·phores To send (a message) or to signal by semaphore.
[Greek sēma, sign + -phore.]
sem′a·phor′ic adj.sem′a·phor′i·cal·ly adv.semaphore (ˈsɛməˌfɔː) n1. (Telecommunications) an apparatus for conveying information by means of visual signals, as with movable arms or railway signals, flags, etc2. (Telecommunications) a system of signalling by holding a flag in each hand and moving the arms to designated positions to denote each letter of the alphabetvb (Telecommunications) to signal (information) by means of semaphore[C19: via French, from Greek sēma a signal + -phore] semaphoric, ˌsemaˈphorical adj ˌsemaˈphorically advsem•a•phore (ˈsɛm əˌfɔr, -ˌfoʊr)
n., v. -phored, -phor•ing. n. 1. an apparatus for conveying information by means of visual signals, as a light whose position may be changed. 2. a system of signaling, esp. one by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc. v.t., v.i. 3. to signal by semaphore or by some system of flags. [1810–20; < Greek sêma sign + -phore] sem`a•phor′ic (-ˈfɔr ɪk, -ˈfɒr-) sem`a•phor′i•cal, adj. sem`a•phor′i•cal•ly, adv. semaphoreany of various types of signaling systems using flags, mechanical arms, etc. — semaphorist, n. — semaphoric, semaphorical, adj.See also: Flagssemaphore
Past participle: semaphored
Gerund: semaphoring
| Imperative |
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| semaphore | | semaphore |
| Present |
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| I semaphore | | you semaphore | | he/she/it semaphores | | we semaphore | | you semaphore | | they semaphore |
| Preterite |
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| I semaphored | | you semaphored | | he/she/it semaphored | | we semaphored | | you semaphored | | they semaphored |
| Present Continuous |
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| I am semaphoring | | you are semaphoring | | he/she/it is semaphoring | | we are semaphoring | | you are semaphoring | | they are semaphoring |
| Present Perfect |
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| I have semaphored | | you have semaphored | | he/she/it has semaphored | | we have semaphored | | you have semaphored | | they have semaphored |
| Past Continuous |
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| I was semaphoring | | you were semaphoring | | he/she/it was semaphoring | | we were semaphoring | | you were semaphoring | | they were semaphoring |
| Past Perfect |
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| I had semaphored | | you had semaphored | | he/she/it had semaphored | | we had semaphored | | you had semaphored | | they had semaphored |
| Future |
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| I will semaphore | | you will semaphore | | he/she/it will semaphore | | we will semaphore | | you will semaphore | | they will semaphore |
| Future Perfect |
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| I will have semaphored | | you will have semaphored | | he/she/it will have semaphored | | we will have semaphored | | you will have semaphored | | they will have semaphored |
| Future Continuous |
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| I will be semaphoring | | you will be semaphoring | | he/she/it will be semaphoring | | we will be semaphoring | | you will be semaphoring | | they will be semaphoring |
| Present Perfect Continuous |
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| I have been semaphoring | | you have been semaphoring | | he/she/it has been semaphoring | | we have been semaphoring | | you have been semaphoring | | they have been semaphoring |
| Future Perfect Continuous |
|---|
| I will have been semaphoring | | you will have been semaphoring | | he/she/it will have been semaphoring | | we will have been semaphoring | | you will have been semaphoring | | they will have been semaphoring |
| Past Perfect Continuous |
|---|
| I had been semaphoring | | you had been semaphoring | | he/she/it had been semaphoring | | we had been semaphoring | | you had been semaphoring | | they had been semaphoring |
| Conditional |
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| I would semaphore | | you would semaphore | | he/she/it would semaphore | | we would semaphore | | you would semaphore | | they would semaphore |
| Past Conditional |
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| I would have semaphored | | you would have semaphored | | he/she/it would have semaphored | | we would have semaphored | | you would have semaphored | | they would have semaphored |
semaphore
Signalling by means of two flags or mechanical arms, held in various positions to represent letters.Thesaurus| Noun | 1. |  semaphore - an apparatus for visual signaling with lights or mechanically moving armsapparatus, setup - equipment designed to serve a specific function | | Verb | 1. | semaphore - send signals by or as if by semaphoresignal, signalise, signalize, sign - communicate silently and non-verbally by signals or signs; "He signed his disapproval with a dismissive hand gesture"; "The diner signaled the waiters to bring the menu" | | 2. | semaphore - convey by semaphore, of informationcommunicate, intercommunicate - transmit thoughts or feelings; "He communicated his anxieties to the psychiatrist" |
semaphoreverbTo communicate by means of such devices as lights or signs:flag, signal.Translationssemaphore (ˈseməfoː) noun a system of signalling with flags held in each hand. He signalled the message to them in semaphore. 旗語 旗语信号系统semaphore
semaphore (sĕm`əfôr'), device for the visible transmission of messages. The marine semaphore, used by day between ships or between a ship and the shore, consists essentially of a post at the top of which are two pivoted arms. The arms are connected by light gearing to two operating levers. Each letter of the alphabet and each numeral is indicated by a different placing of the arms. The system can also be used by the signalman through motions of his own arms, with or without small flags as indicators. In the railroad semaphore a single projecting arm pivoted at one end and attached to a vertical post is devised to take three positions. Horizontal indicates stop, and vertical, all clear; the inclined position indicates that the locomotive may go ahead under control expecting to be stopped. See signalingsignaling,
transmission of information by visible, audible, or other detectable means. Since prehistoric times humans have sought and employed ever more effective means of communicating over distance. Signal fires on mountain tops announced awaited events.
..... Click the link for more information. .Semaphore a fixed signaling device used on railroads equipped with semiautomatic block signaling, staff systems, and centralized switches and signals. One, two, or three arms are mounted on a semaphore tower together with signal actuators to change the position of the arms. A particular position of the arms signals the locomotive engineer that he is cleared to proceed, has orders to stop, or must change speed. At night or when the visibility is poor as a result of fog, snow, or rain, semaphores are supplemented with signal lights. The order to stop is given when the upper arm of the semaphore is horizontal and the red stop light is on. The order to reduce speed is given when the lower arms are positioned along the axis of the tower and a yellow light is on. When the upper arm is at an angle of 135° to the axis of the tower and the light is green, the track is clear and the train is permitted to move at the normal speed. semaphore[′sem·ə‚fȯr] (computer science) A memory cell that is shared by two parallel processes which rely on each other for their continued operation, and that provides an elementary form of communication between them by indicating when significant events have taken place. semaphore (programming, operating system)The classic method forrestricting access to shared resources (e.g. storage) in amulti-processing environment. They were invented byDijkstra and first used in T.H.E operating system.
A semaphore is a protected variable (or abstract data type) which can only be accessed using the followingoperations:
P(s)Semaphore s;while
V(s)Semaphore s; s = s+1;
Init(s, v)Semaphore s;Int v; s = v;
P and V stand for Dutch "Proberen", to test, and "Verhogen",to increment. The value of a semaphore is the number of unitsof the resource which are free (if there is only one resourcea "binary semaphore" with values 0 or 1 is used). The Poperation busy-waits (or maybe sleeps) until a resource isavailable whereupon it immediately claims one. V is theinverse, it simply makes a resource available again after theprocess has finished using it. Init is only used toinitialise the semaphore before any requests are made. The Pand V operations must be indivisible, i.e. no other processcan access the semaphore during the their execution.
To avoid busy-waiting, a semaphore may have an associatedqueue of processes (usually a FIFO). If a process does aP on a semaphore which is zero the process is added to thesemaphore's queue. When another process increments thesemaphore by doing a V and there are tasks on the queue, oneis taken off and resumed.semaphore(1) A hardware or software flag used to indicate the status of some activity. See flag.
(2) A shared space for interprocess communications (IPC) controlled by "wake up" and "sleep" commands. The source process fills a queue and goes to sleep until the destination process uses the data and tells the source process to wake up. See IPC.MedicalSeeflagFinancialSeeFlagsemaphore
Related to semaphore: MutexSynonyms for semaphoreverb to communicate by means of such devices as lights or signsSynonymsWords related to semaphorenoun an apparatus for visual signaling with lights or mechanically moving armsRelated Wordsverb send signals by or as if by semaphoreRelated Words- signal
- signalise
- signalize
- sign
verb convey by semaphore, of informationRelated Words- communicate
- intercommunicate
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