An active mechanical waveguide including an ultrasonically-transmissive material and a plurality of reflection points defined along a length of the waveguide may be dampened using a damping device on a plurality of support members for the waveguide and/or using a damping device on the waveguide itself, and variable spacing of support members and/or constant tensioning of the waveguide may also be used.

To provide high-accuracy assessment of a remaining life of a composite material structure. A remaining life assessment system 5 for composite material structure includes: a load history assessment part 7 that calculates a history of load on a composite material based on output from a first sensor attached to the composite material; a state quantity assessment part 10 that calculates a state quantity of the composite material based on output from the first sensor or a second sensor; a state quantity change database 13 that holds previously recorded relation between the load history and the state quantity of the composite material; and a comparative assessment part 12 that compares the calculated load history and state quantity with the load history and state quantity stored in the state quantity change database 13.

To provide high-accuracy assessment of a remaining life of a composite material structure. A remaining life assessment system 5 for composite material structure includes: a load history assessment part 7 that calculates a history of load on a composite material based on output from a first sensor attached to the composite material; a state quantity assessment part 10 that calculates a state quantity of the composite material based on output from the first sensor or a second sensor; a state quantity change database 13 that holds previously recorded relation between the load history and the state quantity of the composite material; and a comparative assessment part 12 that compares the calculated load history and state quantity with the load history and state quantity stored in the state quantity change database 13.

A bi-state bifurcation-based control system and method for nonlinear resonators, which utilizes a control loop to servo on the edge of the bifurcation jump, either at the maximum on point prior to the Duffing bifurcation jump or along the rising edge of the parametric bifurcation.

A bi-state bifurcation-based control system and method for nonlinear resonators, which utilizes a control loop to servo on the edge of the bifurcation jump, either at the maximum on point prior to the Duffing bifurcation jump or along the rising edge of the parametric bifurcation.

A method for estimating the state of wear of a plain bearing comprises: establishing a time profile of at least one friction event from a structure borne noise signal by a mathematical friction event model, determination of a measure, which characterizes at least one friction event based on a time duration of the at least one friction event, the amplitude of the at least one friction event and/or an integral measure over the at least one friction event, combination of the measure, accumulated over time, with an angle indication for the at least one friction event at the circumference of the plain bearing in order to determine a spatially resolved wear model of the plain bearing, wherein the spatially resolved wear model is obtained by an estimating filter, and outputting a signal in accordance with the wear model to characterize the state of wear.

A payment reader includes a tamper detection system having a first sensor element disposed on a circuit board of the tamper detection circuit; a second sensor element disposed within an interior surface of a housing of the tamper detection circuit; and a guard ring disposed on the circuit board of the tamper detection circuit configured to form an electrical connection with the first sensor element in response to injection of conductive fluid thereby indicating tampering with the tamper detection circuit, wherein the guard ring is configured to be on a plane different from the first sensor element to prevent unintentional activation of the tamper detection circuit.

A rock breaking device and a method of monitoring a condition of a tool of a rock breaking device is provided. The rock breaking device includes a frame, a tool, a device for generating stress waves in the tool, measuring means for measuring the stress wave propagating in the tool and at least one computing unit for monitoring a condition of the tool on the basis of the measured stress wave. The at least one computing unit is configured to determine a condition of the tool on the basis of a time of propagation of at least one reflected stress wave component of the stress wave and at least one additional property of the same reflected stress wave component.

A rock breaking device and a method of monitoring a condition of a tool of a rock breaking device is provided. The rock breaking device includes a frame, a tool, a device for generating stress waves in the tool, measuring means for measuring the stress wave propagating in the tool and at least one computing unit for monitoring a condition of the tool on the basis of the measured stress wave. The at least one computing unit is configured to determine a condition of the tool on the basis of a time of propagation of at least one reflected stress wave component of the stress wave and at least one additional property of the same reflected stress wave component.

A magnetic tunnel junction (MTJ) based sensor device includes a MTJ element and processing circuitry. The MTJ element includes a free layer, a pinned layer, an elastic layer, and a tunnel barrier. The free layer is spaced apart from the pinned layer by the tunnel barrier and the elastic layer. The processing circuitry is configured to measure a resistance at the MTJ element and determine whether mechanical shock and vibration has occurred based on the resistance at the MTJ element.