Showing papers on "Wireless sensor network published in 1988"

Network structures for distributed situation assessment

Abstract: A new approach to situation assessment is an automated distributed sensor network (DSN) consisting of many "intelligent" sensor devices that can pool their knowledge to achieve an accurate overall assessment of a situation. Laboratory experiments were conducted to investigate potential DSN organizations and to ascertain some general design principles. These experiments have been performed with a network of "sensor nodes," each of whom sees only a small portion of the entire environment and attempts to identify the environmental mobile entities as quickly as possible. To do this, they must cooperatively communicate their hypotheses and data, using a limited number of messages. Two general DSN organizations were tested. The first was hierarchical. The second was an "anarchic committee" whose nodes could each send messages to one, some, or all other nodes. The performance of the committee organization consistently surpassed the hierarchical one. This lent support to the contention that DSN architectures need to emphasize cooperative aspects of problem-solving. A machine-based simulation of such a network that achieved performance levels comparable to that of the human committee DSN organization was also constructed and tested. Because most situation assessment communications concern hypothesis updating and revision, minimizing communication requirements through the concept of active "hypothesis processes," which are responsible for predicting their own evolution over time, is suggested.

Distributed and multiplexed fibre-optic sensor systems

Abstract: The unique advantages afforded in a number of application areas by the use of distributed fibre-optic sensor (DFOS) systems have been recognized by many researchers Approaches described to date can be categorized as being either ‘intrinsic-distributed’ or ‘quasi-distributed’ In the case of intrinsic-distributed sensing, a single length of fibre forms an extended sensor element which senses the measurand field continuously over its entire length, whereas quasi-distributed sensing approaches utilize discrete fibre or non-fibre sensor elements typically arranged in a linear array More geometrically versatile sensor network topologies can also be formed by multiplexing several discrete ‘point’ sensors with common input/output fibres This paper reviews this broad and rapidly expanding area of distributed and multiplexed optical fibre sensor technology

Optically Powered Sensors

Abstract: Many advanced systems such as next generation aircraft and automated factories require highly reliable, precise control functions. The designers of these systems are specifying fiber optics for not only interconnecting the sensors and actuators to the control circuits but also providing a passive (i.e. no electrical power) sensor mechanism. Optical sensors that have been developed can provide high sensitivity, EMI/EMP immunity, light weight, high reliability, low cost, and a single fiber for input and output of signals.

Distributed and Multiplexed Fiber-Optic Sensors

Abstract: Many authors have recognised the unique advantages afforded in a number of application areas by the use of distributed fiber-optic sensor (DFOS) systems, which can be formed by combining fiber sensing and telemetry [1-11]. Approaches described to date can be categorized as being either 'intrinsic distributed' or 'quasi-distributed'. In the case of intrinsic distributed sensing, a single length of fiber forms an extended sensor element which senses the measurand field continuously over its entire length, whereas quasi-distributed sensing approaches utilize discrete sensor elements [12-15] arranged in a linear array or other, more geometrically versatile network topology.