A reflected-wave processing apparatus according to one embodiment of the present invention may comprise: a reference signal generation unit for applying, to a cable, a first reference signal, the frequency of which increases over time, and a second reference signal, the frequency of which decreases over time; a reflected-signal acquisition unit for acquiring a first reflected signal and a second reflected signal which are reflected from the cable upon applying the first and second reference signals thereto; and a signal analysis unit for analyzing the first and second reflected signals.

A spectrum analyzer for a signal I.sub.RF comprising a plurality of frequencies f.sub.i comprises N entities each made up of a structure formed by a stack of magnetic and non-magnetic layers having in at least one of the magnetic layers a magnetic configuration in the shape of a vortex, the excitation modes of the magnetic configuration being suitable for detecting the frequencies contained in an incident signal in real time, each entity having a first lower electrode and a second upper electrode, a voltage-measuring device suitable for measuring an electric voltage showing the presence of a frequency f.sub.k in the analyzed signal I.sub.RF, the device being connected to the lower electrode and to the upper electrode, a measurement-processing device suitable for determining the value of the frequencies f.sub.k in the signal I.sub.RF, and a line carrying the signal to be analyzed to each of the entities.

A spectrum analyzer for a signal I.sub.RF comprising a plurality of frequencies f.sub.i comprises N entities each made up of a structure formed by a stack of magnetic and non-magnetic layers having in at least one of the magnetic layers a magnetic configuration in the shape of a vortex, the excitation modes of the magnetic configuration being suitable for detecting the frequencies contained in an incident signal in real time, each entity having a first lower electrode and a second upper electrode, a voltage-measuring device suitable for measuring an electric voltage showing the presence of a frequency f.sub.k in the analyzed signal I.sub.RF, the device being connected to the lower electrode and to the upper electrode, a measurement-processing device suitable for determining the value of the frequencies f.sub.k in the signal I.sub.RF, and a line carrying the signal to be analyzed to each of the entities.

Methods for locating noise in a CATV system are disclosed. The methods may use a probe or instrument configured to be coupled to a port of the CATV system. The probe may be operable to selectively filter signals in the CATV system to suppress the frequencies at which noise may be present in the CATV system. In some embodiments, the methods may also use a signal level meter, and the probe may be configured to be coupled to the signal level meter to detect and locate noise in the CATV system.

Methods for locating noise in a CATV system are disclosed. The methods may use a probe or instrument configured to be coupled to a port of the CATV system. The probe may be operable to selectively filter signals in the CATV system to suppress the frequencies at which noise may be present in the CATV system. In some embodiments, the methods may also use a signal level meter, and the probe may be configured to be coupled to the signal level meter to detect and locate noise in the CATV system.

A measurement data based method for identifying wind turbine generators which cause sub-synchronous oscillations in a complex power system has a theoretical foundation of the open-loop modal resonance and the parallel filter design. The advantages of the present invention are as follows. 1) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system using measurement data instead of parametric model. Hence, it simplifies the computation and reduces the modeling cost effectively. 2) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system precisely with reduced amount of measurement data, reducing the cost of hardware and data measurement effectively. 3) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system based on the open-loop modal resonance theory.

Systems and methods relate to electric propulsor fault detection. An exemplary system includes at least a first inverter configured to accept a direct current and produce an alternating current, a first propulsor, a first motor operatively connected with the first propulsor and powered by the alternating current, and at least a noise monitoring circuit electrically connected with the direct current and configured to detect electromagnetic noise and disengage the at least an inverter as a function of the electromagnetic noise.

Systems and methods relate to electric propulsor fault detection. An exemplary system includes at least a first inverter configured to accept a direct current and produce an alternating current, a first propulsor, a first motor operatively connected with the first propulsor and powered by the alternating current, and at least a noise monitoring circuit electrically connected with the direct current and configured to detect electromagnetic noise and disengage the at least an inverter as a function of the electromagnetic noise.

A method for determining feature signal filters for preparing signal measurement data sequences of a plurality of measurement variables for experimentally determining a mathematical model which maps model measurement data for at least one target signal sensor (7) on the basis of detected measurement data of a plurality of feature signal sensors (5) is disclosed. Further disclosed is a method for determining a mathematical model (16) which maps model measurement data for at least one target signal sensor (7) on the basis of detected measurement data of a plurality of feature signal sensors (5), wherein training input measurement data sequences (19) ascertained by the feature signal sensors (5) are mapped onto at least one training output measurement data sequence (18) ascertained by at least one target signal sensor (7).

A method for determining feature signal filters for preparing signal measurement data sequences of a plurality of measurement variables for experimentally determining a mathematical model which maps model measurement data for at least one target signal sensor (7) on the basis of detected measurement data of a plurality of feature signal sensors (5) is disclosed. Further disclosed is a method for determining a mathematical model (16) which maps model measurement data for at least one target signal sensor (7) on the basis of detected measurement data of a plurality of feature signal sensors (5), wherein training input measurement data sequences (19) ascertained by the feature signal sensors (5) are mapped onto at least one training output measurement data sequence (18) ascertained by at least one target signal sensor (7).