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A repeating pattern in a time series; examples are annual and daily patterns.

[Etymology: Gk: ‘circle’] One set of ordered events or phenomena that recur without change in their essentials; hence, like one lap of a circle, the passing of one set leaves circumstances apparently unchanged except for the passage of time. For a literal lap of a circle, the terms ‘revolution’ and ‘turn’ are usual, e.g. in revolutions per minute for the rotation of an engine, and in ampere·turns for magnetomotive force from the windings of an electric motor. (The expressions two-cycle and four-cycle applied to engines, in contrast, refers to the logical sequence of valve action.)

In much of science the series of phenomena is a continuum of change, e.g. in amplitude of a signal, as with electric alternating current. The standard for electric power in North America is for 60 cycles per second, the household supply cycling from 0 up to +165 V, progressively down through 0 to -165 V, then back to 0 to deliver the mean 110 V. (Elsewhere 50 cycles per second is usual, with a higher voltage; see r.m.s.) Radio and other electromagnetic radiations, and related features of particle physics, have a similar oscillation or waveform, usually of vastly greater frequency. While such oscillations might be seen as different from the circle, they are usually expressible as trigonometric functions of angular variables that recurrently lap the circle.

The number of cycles per second is the most obvious applicable measure; abbreviated to c.p.s. and vernacularly just ‘cycles’, this is the hertz. For a travelling entity the quotient speed over hertz gives wavelength; expressed reciprocally to distance, this gives wave number.

(1) A single event that is repeated. For example, in a carrier frequency, one cycle is one complete wave.

(2) A set of events that is repeated. For example, in a polling system, all of the attached terminals are tested in one cycle. See machine cycle and memory cycle.

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Interval or unit of time specified within a contract, when the contract is for a longer time period. For example, an advertiser may have a television broadcast media purchase contract for a period of one year. Within that year contract, there may be specified four 13-week periods of television programming. Each 13-week period is considered a cycle. The advertiser may change or cancel the contract (with proper notice, of course) at the end of a cycle.

A cycle is also used as a base for payment of talent fees in a commercial. Talent will be paid a fee for the specified length of a cycle.

1. Grouping of accounts in batches, which are processed as a single unit, to distribute the work load and make identification of accounts easier. Checking account statements are processed in batch cycles, as are credit cards and installment loans.

2. Business cycle-the periodic expansion and contraction of the economy, as measured by growth in the U.S. Gross Domestic Product (GDP). According to the U.S. Bureau of Economic Research, which tracks economic trends, business cycles, on average, last about 52 months or 2l⁄2 years. Among the factors affecting the rate of economic expansion (as the economy moves from recession to growth and stable employment) are expansion and contraction in bank credit, which is influenced by Federal Reserve Monetary Policy. See also Lagging Indicators; Leading Indicators.

noun

A course, process, or journey that ends where it began or repeats itself: circle, circuit, orbit, round, tour, turn. See repetition.

1. n. The basic unit of computation. What every hacker wants more of (noted hacker Bill Gosper described himself as a “cycle junkie”). One can describe an instruction as taking so many clock cycles. Often the computer can access its memory once on every clock cycle, and so one speaks also of memory cycles. These are technical meanings of cycle. The jargon meaning comes from the observation that there are only so many cycles per second, and when you are sharing a computer the cycles get divided up among the users. The more cycles the computer spends working on your program rather than someone else's, the faster your program will run. That's why every hacker wants more cycles: so he can spend less time waiting for the computer to respond.

2. By extension, a notional unit of human thought power, emphasizing that lots of things compete for the typical hacker's think time. “I refused to get involved with the Rubik's Cube back when it was big. Knew I'd burn too many cycles on it if I let myself.”

3. vt. Syn. bounce (sense 4), from the phrase ‘cycle power’. “Cycle the machine again, that serial port's still hung.”

Any situation in which a voting procedure, choosing among multiple options, would choose A over B, B over C …, i over j, and j over A. The best-known example is the cycle in simple majority rule, discovered by Condorcet in 1785, but any majority rule short of unanimity may generate a cycle. Even if A beats B only if at least all the voters except one prefer A to B, there may still be a cycle. When a cycle exists, the will of the people is undetermined. Whatever is chosen, a majority of the people would rather have had something else.

cycle, a group of works, usually narrative poems, that either share a common theme or subject (e.g. the Trojan war, Charlemagne, the Knights of the Round Table), or are linked together as a sequence. In addition to epics, sagas, romances, and chansons de geste, which scholars have categorized into different cycles, the mystery plays of the Middle Ages that were performed as a sequence during the same festival at a particular place are referred to as the York Cycle, the Chester Cycle etc. The term is also applied to sequences of sonnets by the same author, and sometimes to sequences of novels or stories (see roman‐fleuve).

Adjective: cyclic.

When a repeating wave rises from zero to a positive maximum then back to zero and on to a negative maximum and back to zero it is said to have completed one cycle.

The aggregate of accumulated literature, plays or musical works treating the same theme. In poetry, the term is typically applied to epic or narrative poems about a mythical or heroic event or character.

Quotes:

"Each thing is of like form from everlasting and comes round again in its cycle." - Marcus Aurelius

"What has been will be again. What has been done will be done again... [Ecclesiastes 1:9]" - Bible

"All motion is cyclic. It circulates to the limits of its possibilities and then returns to its starting point." - Robert Collier

"Everything comes if a man will only wait." - Benjamin Disraeli

"That which the fountain sends forth returns again to the fountain." - Henry Wadsworth Longfellow

"Events tend to recur in cycles..." - W. Clement Stone

See more famous quotes about Cycles

1. any recurring period of time in which certain events or operations occur, complete themselves, or repeat themselves in a regular sequence.
2. any sequence of changes occurring in a system in which the system is eventually restored to its initial state.
3. (in biochemistry) any closed sequence of metabolic reactions in which an end product acts as a reactant in the initiation of the cycle, e.g. the tricarboxylic-acid cycle.
4. (in ecology) any closed sequence of large-scale processes that describes the nutritional interdependence of animals, plants, and microorganisms, e.g. the nitrogen cycle.
5. to process through a cycle or cyclic system; to pass through cycles or to vary in a cyclical manner.

A succession or recurring series of events.

• cardiac c. — a complete cardiac movement, or heartbeat, including systole, diastole, and the intervening pause.
— The cycle includes eight separate phases: (1) isovolumetric contraction; (2) maximum ejection; (3) reduced ejection; (4) protodiastole (onset of ventricular relaxation); (5) isovolumetric relaxation; (6) rapid flow; (7) diastasis (onset of atrial contraction); (8) atrial systole.
• cell c. — the cycle of biochemical and morphological events occurring in a dividing cell population; it consists of the S phase, occurring toward the end of interphase, in which DNA is synthesized; the G₂ phase, for gap 2, the interval between S and M; the M phase, for mitosis, consisting of the four phases of mitosis; and the G₁ phase, which lasts from the end of M until the start of S phase of the next cycle. Fully differentiated cells are nondividing and are said to be in G₀.

  Cell cycle. By permission from Booth DM, Small Animal Clinical Pharmacology and Therapeutics, Saunders, 2000

• citric acid c. — see tricarboxylic acid cycle.
• estrus c. — see estrous cycle.
• Krebs c. — see tricarboxylic acid cycle.
• ovarian c. — the sequence of physiological changes in the ovary involved in ovulation. See also ovulation and reproduction.
• reproductive c. — the cycle of physiological changes in the reproductive organs, from the time of fertilization of the ovum through gestation and parturition. See also reproduction.
• sex c., sexual c. — 1. the physiological changes recurring regularly in the reproductive organs of female mammals when pregnancy does not supervene.
— 2. the period of sexual reproduction in an organism that also reproduces asexually.
• tricarboxylic acid c. — see tricarboxylic acid cycle.
• urea c. — a cyclic series of reactions that produce urea, a major route for removal of the ammonia produced in the metabolism of amino acids in the liver and kidney. See also urea.

A succession of events.

• Cycles - cycle: open, pedaled or engine-powered, single-passenger vehicle, usu. having two wheels in tandem
• Advertising - cycle: schedule of periodic, often quarterly, residual payments to actors, models, and singers
• Schools, Styles, and Forms - cycle: collection of poems or narratives related by common subject matter, usu. a central character
• Periods of Time - cycle: regular, recurring interval of time; set period of days or years
• Shapes - cycle: circular or spiral arrangement

Dansk (Danish)
n. - cyklus, omløbstid, kredsløb, hertz
v. intr. - køre på cykel, kredse, rotere
v. tr. - gennemgå en cyclus

Nederlands (Dutch)
cyclus, kringloop, tijdkring, fiets(en), cirkelen, cyclisch verlopen

Français (French)
n. - vélo, bicyclette, cycle
v. intr. - faire du vélo
v. tr. - faire du vélo

Deutsch (German)
v. - Fahrrad fahren
n. - Fahrrad, Zyklus, Kreislauf

Ελληνική (Greek)
v. - ανακυκλώνω/-ομαι, κινούμαι με (μοτο)ποδήλατο
n. - κύκλος, τακτική ή περιοδική επανάληψη, (μοτο)ποδήλατο

Italiano (Italian)
andare in bicicletta, bicicletta, ciclo

Português (Portuguese)
v. - andar de bicicleta, passar por um ciclo
n. - ciclo (m), circuito (m), época (f), alternação (f) (Eletr.), verticilo (m) (Bot.)

Русский (Russian)
кружиться, ездить на велосипеде, велосипед, цикл

Español (Spanish)
n. - bicicleta, bici, ciclo, período
v. intr. - irse en bicicleta
v. tr. - ir en bicicleta

Svenska (Swedish)
v. - cykla, kretsa
n. - cykel, kretslopp, omloppstid, period, takt (i motor), serie, motorcykel

中文（简体）(Chinese (Simplified))
周期, 自行车, 循环, 骑自行车, 轮转, 使循环, 使轮转

中文（繁體）(Chinese (Traditional))
n. - 周期, 自行車, 迴圈
v. intr. - 循環, 騎自行車, 輪轉
v. tr. - 使循環, 使輪轉

한국어 (Korean)
n. - 순환, 한 시대, 자전거
v. intr. - 순환하다, 자전거를 타고 가다
v. tr. - 순환시키다

日本語 (Japanese)
n. - 一巡り, 周期, 自転車, オートバイ, 一組, 詩歌, 周波
v. - 自転車に乗る, 循環する, 周期的に起こる

العربيه (Arabic)
‏(فعل) ركب دراجه (الاسم) دورة, دراجه, سلسله كامله‏

עברית (Hebrew)
n. - ‮מחזור, מעגל, אופניים, קובץ-שירים, תקופה, סדרת פעולות או מצבים חוזרים (פיסיקה)‬
v. intr. - ‮רכב על אופניים, נע במעגלים‬
v. tr. - ‮רכב על אופניים‬

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