An elastic matrix determination method and a vibration analysis method for a laminated iron core, with which it is possible to optimally determine an elastic modulus of a laminated iron core. When a vibration analysis of a laminated iron core obtained by laminating steel sheets is performed by using a configuration expression indicating a relationship between stress and strain in a matrix display by using an elastic matrix, a shear modulus in two surfaces including a laminating direction of the laminated iron core included in the elastic matrix in the configuration expression is determined in consideration of slip between laminated steel sheets.

A measurement device includes a measurement unit that measures a physical property of a measurement target by causing the measurement target to vibrate through an application of an ultrasonic wave, the measurement unit including a first mode that measures the physical property using a first burst wave sensitive in a first predetermined range of physical property values and a second mode that measures the physical property using a second burst wave sensitive in a second range of physical property values different from the first range, and a control unit that controls the measurement unit to execute at least one of the first mode and the second mode.

A test arrangement for fatigue testing a wind turbine blade, including a floor-mounted test rig having a fixing device for fixing the wind turbine blade to the test rig and an excitation assembly for exciting the wind turbine blade at a test frequency, wherein the test rig includes a liquid tank having a chamber containing a predefined liquid, wherein the liquid in the liquid tank has a resonance frequency depending on the amount of liquid in the liquid tank and the chamber geometry is provided.

A test arrangement for fatigue testing a wind turbine blade, including a floor-mounted test rig having a fixing device for fixing the wind turbine blade to the test rig and an excitation assembly for exciting the wind turbine blade at a test frequency, wherein the test rig includes a liquid tank having a chamber containing a predefined liquid, wherein the liquid in the liquid tank has a resonance frequency depending on the amount of liquid in the liquid tank and the chamber geometry is provided.

Disclosed are apparatus and methods for enhancing operation of an ultrasonic sensing device for determining the status of an object near such ultrasonic sensing device. From the ultrasonic sensing device, an emission signal having a current frequency or band in an ultrasonic frequency range is emitted. Ultrasonic signals are received and analyzed to detect one or more objects near or contacting the ultrasonic sensing device. After expiration of a predefined time period of emitting the emission signal, a background noise signal is detected from an environment of the ultrasonic device and background noise metrics are estimated based on the background noise signal. It is then determined whether the current frequency of the emission signal is optimized based on the background noise metrics. A next frequency or band is selected and the emission signal is emitted at the next frequency or band if it is determined that the current frequency or band is not optimum. The operations of detecting, estimating, determining, and selecting are repeated after each time a next frequency or band is selected and the emission signal is emitted at such next frequency or band.

Disclosed are apparatus and methods for enhancing operation of an ultrasonic sensing device for determining the status of an object near such ultrasonic sensing device. From the ultrasonic sensing device, an emission signal having a current frequency or band in an ultrasonic frequency range is emitted. Ultrasonic signals are received and analyzed to detect one or more objects near or contacting the ultrasonic sensing device. After expiration of a predefined time period of emitting the emission signal, a background noise signal is detected from an environment of the ultrasonic device and background noise metrics are estimated based on the background noise signal. It is then determined whether the current frequency of the emission signal is optimized based on the background noise metrics. A next frequency or band is selected and the emission signal is emitted at the next frequency or band if it is determined that the current frequency or band is not optimum. The operations of detecting, estimating, determining, and selecting are repeated after each time a next frequency or band is selected and the emission signal is emitted at such next frequency or band.

Sensing apparatuses and method of making the sensing apparatuses are disclosed herein. In some variations, a sensing apparatus can comprise at least one optical waveguide, and at least one whispering gallery mode (WGM) resonator configured to propagate a set of WGMs, where the WGM resonator communicates to the at least one optical waveguide a set of signals corresponding to the set of WGMs. In some variations, a polymer structure may encapsulate the at least one WGM resonator and/or the at least one optical waveguide. Furthermore, in some variations, the WGM resonator(s) may have one or more selectable modes with different bandwidth and sensitivity for sensing, which may, for example, enable tailoring the sensing apparatus to specific applications having certain bandwidth and/or sensitivity requirements.

Sensing apparatuses and method of making the sensing apparatuses are disclosed herein. In some variations, a sensing apparatus can comprise at least one optical waveguide, and at least one whispering gallery mode (WGM) resonator configured to propagate a set of WGMs, where the WGM resonator communicates to the at least one optical waveguide a set of signals corresponding to the set of WGMs. In some variations, a polymer structure may encapsulate the at least one WGM resonator and/or the at least one optical waveguide. Furthermore, in some variations, the WGM resonator(s) may have one or more selectable modes with different bandwidth and sensitivity for sensing, which may, for example, enable tailoring the sensing apparatus to specific applications having certain bandwidth and/or sensitivity requirements.

Disclosed herein are a soil moisture sensor and an operating method thereof. The soil moisture sensor includes a first probe including a pair of first electrodes extending in a first direction; a first resonance circuit connected to the pair of first electrodes of the first probe through a pair of first ports, and configured such that a first AC signal is applied thereto; a second resonance circuit having the same impedance as the first resonance circuit, and configured such that a second AC signal having the same characteristics as the first AC signal while being a reference AC signal is applied thereto; and a determination circuit configured to receive a first electrical signal and a second electrical signal and to determine the moisture in the soil based on the first resonant frequency of the first electrical signal and the second resonant frequency of the second electrical signal.

A method and apparatus for inspecting a fusion joint is provided. The apparatus includes a processor, an ultrasound (“US”) probe in communication with the processor, and a database comprising classification rules. The processor is configured to generate an initial set of US scanning positions about the fusion joint based on information of at least one of the US probe and the fusion joint; measure, via the US probe, a US pulse-echo spectrum from at least two of the initial US scanning positions; compare each measured US pulse-echo spectrum with one or more known US pulse-echo spectrums; classify each measured US pulse-echo spectrum according to the classification rules; and evaluate an aggregate of measured US pulse-echo spectrums to determine if the fusion joint is defective.