A garrison ration (or mess ration for food rations of this type) is a type of military ration. Usually distinct from field rations, the term has varying meanings, but generally refers to either rations issued to personnel at a camp, installation, or other garrison; allowance (in the form of scrip or legal tender) allotted to personnel to purchase goods or rations sold in a garrison; the rations purchased with the aforementioned allowance; or a type of issued ration.In some instances, what determines a ration to be a garrison ration depends on situational context. For example, a 1941 United States Army Field Manual defines a "garrison ration" as rations purchased with allowance in peacetime, with a "field ration" being rations issued in wartime or other special circumstances at no cost to those distributing or receiving them.The term is often used in a historical context, but modern equivalents to garrison rations exist, though official use of the term in a present-day context is rare. Wehrmacht German rations were issued on a scale according to the duties and locations of the troops, there were 4 scales of...

Aleatoric music (also aleatory music or chance music; from the Latin word alea, meaning "dice") is music in which some element of the composition is left to chance, and/or some primary element of a composed work's realization is left to the determination of its performer(s). The term is most often associated with procedures in which the chance element involves a relatively limited number of possibilities. The term became known to European composers through lectures by acoustician Werner Meyer-Eppler at the Darmstadt International Summer Courses for New Music in the beginning of the 1950s. According to his definition, "a process is said to be aleatoric ... if its course is determined in general but depends on chance in detail". Through a confusion of Meyer-Eppler's German terms Aleatorik (noun) and aleatorisch (adjective), his translator created a new English word, "aleatoric" (rather than using the existing English adjective "aleatory"), which quickly became fashionable and has persisted. More recently, the variant "aleatoriality" has been introduced. History...

An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It is the optical equivalent of an electronic time domain reflectometer which measures the impedance of the cable or transmission line under test. An OTDR injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. The scattered or reflected light that is gathered back is used to characterize the optical fiber. The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of length of the fiber. Reliability and quality of OTDR equipment The reliability and quality of an OTDR is based on its accuracy, measurement range, ability to resolve and measure closely spaced events, measurement speed, and ability to perform satisfactorily under various environmental extremes and after various types of physical abuse. The instrument is also judged on the basis of its cost, features provided, size, weight...