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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
estimates of pixel intensities or deduced orientation values for points on the surface of an object. See relaxation, optimization. relaxation oscillations the damped output oscillations that occur in some laser oscillators when they are perturbed from steady state. relaxation time the time in which the initial distribution of charge will diminish to 1/e of its original value. relay a device that opens or closes a contact when energized. Relays are most commonly used in power systems, where their function is to detect defective lines or apparatus or other abnormal or dangerous occurrences and to initiate appropriate control action. When the voltage or current in a relay exceeds the specified "pickup" value, the relay contact changes its position and causes an action in the circuit breaker. A decision is made based on the information from the measuring instruments and relayed to the trip coil of the breaker, hence the name "relay." Other relays are used as switches to turn on or off equipment. relay channel a multiterminal channel in which the receiver observes the transmitted signal through two channels: one direct to the transmitter, the other via an intermediate transmitter/receiver pair. reliability the probability that a component or system will function without failure over a specified time period, under stated conditions. reliability criteria a set of operating conditions that the system operator adheres to in order to guarantee secure operation. relocatability the capability for a program to be loaded into any part of memory that is convenient and still execute correctly. relocation register register used to facilitate the placement in varying locations of data and
Cooperative communication based access technique for sensor networks
Published in International Journal of Electronics, 2020
In independent communication, independent paths between user and base station are generated by relay channel. The relay channel can be considered as an auxiliary channel to the direct channel between the source and the destination. The most important feature of cooperative communication is that the signal received from the source is subjected to a certain process by the relay. As a result of each different operation, a different communication protocol is established. Collaborative communication can be divided into two categories; i.e. fixed and selective relay protocols. In fixed relay protocols, the channel sources are fixedly shared by the relay and the source.