Abstract: Monitoring health of dynamic systems includes using speaker recognition techniques. Some embodiments include determining a system-independent statistical (first) model, and determining a healthy system (second) model based on data representing vibrations of multiple healthy systems and the first model and speaker recognition techniques. Vibration data are obtained from a particular system. It is determined whether the particular system is unhealthy based on the vibration data from the particular system and the first model and the second model and speaker recognition techniques. Some embodiments include obtaining training data that represents vibrations of multiple healthy systems. A damage-sensitive parameter is based on the training data. A threshold value that separates damaged systems from healthy systems is based on the training data and the parameter.

Abstract: Monitoring health of dynamic systems includes using speaker recognition techniques. Some embodiments include determining a system-independent statistical (first) model, and determining a healthy system (second) model based on data representing vibrations of multiple healthy systems and the first model and speaker recognition techniques. Vibration data are obtained from a particular system. It is determined whether the particular system is unhealthy based on the vibration data from the particular system and the first model and the second model and speaker recognition techniques. Some embodiments include obtaining training data that represents vibrations of multiple healthy systems. A damage-sensitive parameter is based on the training data. A threshold value that separates damaged systems from healthy systems is based on the training data and the parameter.

Abstract: A method and apparatus for sensing corrosion comprises a casing and a counter-electrode. The casing is made of material that is substantively incompressible at pressures on wires within a structural cable. The casing has a thickness that is not greater than typical interstitial spaces between wires of the structural cable and has a length on an order of a radius of the structural cable. The counter-electrode exchanges electrons with ions of an electrolyte that corrodes the wires of the structural cable. The counter-electrode is embedded in the casing, is exposed to the electrolyte in a window of the casing, and is recessed to avoid contact with any wire of the structural cable when the sensor is deployed among the wires of the structural cable.

Abstract: A method and apparatus for sensing corrosion comprises a casing and a counter-electrode. The casing is made of material that is substantively incompressible at pressures on wires within a structural cable. The casing has a thickness that is not greater than typical interstitial spaces between wires of the structural cable and has a length on an order of a radius of the structural cable. The counter-electrode exchanges electrons with ions of an electrolyte that corrodes the wires of the structural cable. The counter-electrode is embedded in the casing, is exposed to the electrolyte in a window of the casing, and is recessed to avoid contact with any wire of the structural cable when the sensor is deployed among the wires of the structural cable.