A gas analyzer uses continuous sonic signals through a conduit to determine the composition of a gas in the conduit. A transmitting transducer drives sonic signals at a fixed frequency and a second transducer receives the sonic signals. The phase shift between two signals corresponds to the speed of sound through the gas and is related to the composition of the gas. The electronic versions of these signals are processed by lowering, or dividing, the fixed frequency which expands the range of phase shift measurement and allows the determination of an expanded range for the gas composition. In an ozone generation system, the gas analyzer is highly suitable for determining the composition of gases derived from air as a gas of known composition and a calibration point.

The present invention discloses a method for onset time detection of acoustic emission signals based on histogram distance. The method comprises the following steps: acquiring an acoustic emission signal; dividing the signal into two intervals with a sliding point k as the demarcation point; obtaining the relative frequency histograms of two adjacent intervals; obtaining histogram distance of the relative frequency histograms of two adjacent intervals; moving the sliding point k to the next element to obtain two new intervals and generating new histograms of the two new intervals and calculating the histogram distance of two new intervals; searching for the point which gives the maximum value of the histogram distances, and the corresponding time to this point is regarded as the onset time.

The present invention discloses a method for onset time detection of acoustic emission signals based on histogram distance. The method comprises the following steps: acquiring an acoustic emission signal; dividing the signal into two intervals with a sliding point k as the demarcation point; obtaining the relative frequency histograms of two adjacent intervals; obtaining histogram distance of the relative frequency histograms of two adjacent intervals; moving the sliding point k to the next element to obtain two new intervals and generating new histograms of the two new intervals and calculating the histogram distance of two new intervals; searching for the point which gives the maximum value of the histogram distances, and the corresponding time to this point is regarded as the onset time.

This application relates to a method of analyzing dynamic characteristics of a carbon composite material. This application also relates to a method of calculating sensitivity indices for structural stiffness and a viscous damping coefficient of a carbon composite material and a method of analyzing dynamic characteristics of a carbon composite material by using the same. Respective sensitivity indices for structural stiffness and a viscous damping coefficient according to a direction (angle) of carbon fiber for a carbon composite material are calculated. A change in the dynamic characteristics of the carbon composite material is evaluated through a proportional relationship between the sensitivity indices, thereby conducting a more accurate and efficient analysis.

This application relates to a method of analyzing dynamic characteristics of a carbon composite material. This application also relates to a method of calculating sensitivity indices for structural stiffness and a viscous damping coefficient of a carbon composite material and a method of analyzing dynamic characteristics of a carbon composite material by using the same. Respective sensitivity indices for structural stiffness and a viscous damping coefficient according to a direction (angle) of carbon fiber for a carbon composite material are calculated. A change in the dynamic characteristics of the carbon composite material is evaluated through a proportional relationship between the sensitivity indices, thereby conducting a more accurate and efficient analysis.

A NEMS readout system includes a sensor array comprising a plurality of sensors. Each sensor of the plurality of sensors including a resonator with frequency characteristics different from the resonator of each other sensor of the plurality of sensors. A readout signal indicative of a plurality of output signals is collected from the sensor array. Each output signal of the plurality of output signals corresponding to one of the plurality of sensors. An analysis of the plurality of output signals is performed to identify a plurality of resonant frequencies and to detect a frequency shift associated with at least one of the plurality of resonant frequencies.

The present invention relates to a method for recognizing multiple user actions and, more particularly, provided is a method capable of recognizing multiple user actions from a collected sound source when multiple actions are performed in a specific space, and accurately determining a user situation from the recognized multiple user actions.

The present invention relates to a method for recognizing multiple user actions and, more particularly, provided is a method capable of recognizing multiple user actions from a collected sound source when multiple actions are performed in a specific space, and accurately determining a user situation from the recognized multiple user actions.

A quartz crystal microbalance (QCM) sensor includes a crystal plate, a buffer layer, and an electrode. The crystal plate has a first surface and a second surface. The second surface is opposite the first surface. The buffer layer includes a first buffer layer and a second buffer layer. The first buffer layer is disposed on the first surface of the crystal plate. the second buffer layer is disposed on the second surface of the crystal plate. The electrode includes a first electrode and a second electrode. The first electrode is disposed on the first buffer layer. The second electrode is disposed on the second buffer layer. The electrode includes at least one of titanium, scandium, beryllium, cobalt, yttrium, zirconium, technetium, ruthenium, lanthanum, cerium, praseodymium, neodymium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, lutetium, hafnium, rhenium, osmium, americium, curium, berkelium, and californium.

A quartz crystal microbalance (QCM) sensor includes a crystal plate, a buffer layer, and an electrode. The crystal plate has a first surface and a second surface. The second surface is opposite the first surface. The buffer layer includes a first buffer layer and a second buffer layer. The first buffer layer is disposed on the first surface of the crystal plate. the second buffer layer is disposed on the second surface of the crystal plate. The electrode includes a first electrode and a second electrode. The first electrode is disposed on the first buffer layer. The second electrode is disposed on the second buffer layer. The electrode includes at least one of titanium, scandium, beryllium, cobalt, yttrium, zirconium, technetium, ruthenium, lanthanum, cerium, praseodymium, neodymium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, lutetium, hafnium, rhenium, osmium, americium, curium, berkelium, and californium.