TAILIEUCHUNG - Fiber Optics Illustrated Dictionary - Part 69

The Fiber Optics Illustrated Dictionary - Part 69 fills a gap in the literature by providing instructors, hobbyists, and top-level engineers with an accessible, current reference. From the author of the best-selling Telecommunications Illustrated Dictionary, this comprehensive reference includes fundamental physics, basic technical information for fiber splicing, installation, maintenance, and repair, and follow-up information for communications and other professionals using fiber optic components. Well-balanced, well-researched, and extensively cross-referenced, it also includes hundreds of photographs, charts, and diagrams that clarify the more complex ideas and put simpler ideas into their applications context | Fiber Optics Illustrated Dictionary the application. On computer networks for example storage of the nonexistence of certain servers or machines can lead to more efficient polling or routing of processes or network services. If certain printers or fax servers are offline for maintenance negative caching information can be used to prevent overflowing queues. If certain hosts are offline routing of packets can be renegotiated through other servers. If certain elements of an image file do not exist negative caching can be used to prevent expensive production tasks on a printing press or milling machine holding up the line. See NCACHE. negative feedback The propagation of an acoustic or electromagnetic signal in the general opposite direction of the source signal. This often results from backreflection of the outgoing signal or from the signal being circularly fed to the source through another source . a second microphone . In slower-moving phenomena . sound the delay between the original source output and the feedback can magnify the effects of the phenomenon and cause echo. Uncontrolled negative feedback may create undesired loss of gain distortion echoes or other interference but it is not detrimental in all circumstances. In electronics negative feedback in a circuit sometimes called shunt feedback because the circuit is looped back upon itself can help condition a signal. When configured as inverse or degenerative feedback it may help reduce distortion nonlinearity and signal instability in an amplified signal. Optical negative feedback has been proposed as a means to reduce spectral linewidth and noise in frequency modulated FM systems. negative glow A luminous glow which can be observed between an electron-emitting cathode and the Faraday dark space in a cold-cathode discharge tube. See Faraday dark space. negative image An image in which the dark and the light values are reversed or in which the complements of the colors are displayed instead of the .

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