69 results about "Resonance analysis" patented technology

The present invention provides a method for monitoring a condition of an electrical cable, the method comprising providing a reference signal CH0 and a signal CH1, said signal CH1 being the reference signal CH0 after amplitude and phase modulation by a cable impedance Z_DUT of the electrical cable; calculating the cable impedance Z_DUT as a function of the applied signal frequency based on the reference signal CH0 and the signal CH1; and analyzing said cable impedance providing an assessment of the cable condition. A system performing the method is also disclosed.

The invention discloses a multi-fan grid-connected resonance analysis method. The method comprises the following steps: on the basis of an output impedance model of an inverter, establishing a grid-connected equivalent model of a wind power plant; establishing a cable equivalent model according to the cable distribution characteristic under a harmonic state, and establishing the equivalent impedance of fan output power at a PCC (Point of Common Coupling) according to a relationship between the absorption power of the PCC and the fan output power to obtain the total impedance of a distributed wind power grid-connected system. The multi-fan grid-connected resonance analysis method has the advantages that the total impedance is calculated by establishing a distributed wind power grid-connected system model recorded with the cable and fan output power; the system model more accords with practical situations and has an application value and a practical significance for the resonance problem in an accurate analysis system.

A network text analysis called center resonance analysis (CRA) is presented which represents texts (or transcribed conversations) as networks of centering words. The networks of centering words are components of utterances or (specifically noun phrases) that authors and/or speakers deploy in a manner that makes their utterances coherent. A CRA network can be derived for any text, and abstractly represents its main concepts, their influence, and their interrelationships.

The present invention discloses a single-core power cable resonance analysis method based on finite element simulation and an equivalent circuit. The method comprises: using finite element simulation to accurately calculate resistance of per unit length of a core wire of a single-core power cable, inductance of per unit length of the core wire of the single-core power cable, resistance of per unit length of a metal protective layer of the single-core power cable, inductance of per unit length of the metal protective layer of the single-core power cable, and capacitance of per unit length of the core wire to the metal protective layer; and using circuit simulation to simulate and analyze resonant circumstances of the core wire and the metal protective layer of the single-core power cable as well as a ground system under different grounding modes. The method is used in the field of power single-core power cable resonance analysis; and an analysis object is determined, analysis steps are simplified, and required resonant circumstances of any failure point can be provided, so that the method has relatively large reference value and significance for diagnosing and predicting a single-core power cable resonance failure.

The invention relates to a construction method for a differential expression profile model of hepatitis B virus (HBV) infectivity and alcoholic cirrhosis. According to the method, peripheral blood samples of liver cirrhosis patients with HBV infections, alcoholic cirrhosis patients and healthy people are sampled to carry out nulcear magnetic resonance analysis, then a multi-variable statistical analysis is adopted for the resulting spectrograms from the nulcear magnetic resonance analysis to obtain the differential expression profile model of the HBV infectivity and the alcoholic cirrhosis. According to the present invention, the metabonomics analysis method is adopted for analyzing the metabolic products of the liver cirrhosis patients with HBV infections, the alcoholic cirrhosis patients and the healthy people, such that the specific metabolic products related to the pathologic mechanisms of the liver cirrhosis with the HBV infection and the alcoholic cirrhosis are found, the differential expression profile model of the HBV infectivity and the alcoholic cirrhosis is constructed; such that a support is provided for specific diagnosis and treatment of the liver cirrhosis with the HBV infection and the alcoholic cirrhosis. In addition, the invention further relates to a differential expression profile model of the HBV infectivity and the alcoholic cirrhosis.

Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54°44′ relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

The invention relates to an earplug-type moving coil and moving iron mixed earphone. The earplug-type moving coil and moving iron mixed earphone is characterized in that a moving iron unit is installed in a moving coil cavity of a moving coil unit, a frequency divider provides signals for the moving coil unit and the moving iron unit, the moving coil unit is in charge of low and medium frequency sound production, the moving iron unit is in charge of high frequency sound production, and therefore the earphone increases the thickness and analysis of medium frequency, singing of people is richer in feeling and vitality, resonance analysis and raising of high frequency are improved, extremely-high frequency sound can be heard, hearing of people is more abundant, an HIFI high-quality music effect is achieved better, and listeners can experience enjoyment like live HIFI high-quality music better.

A method of designing a magnetic structure for providing a monotonic static magnetic field for magnetic resonance analysis. The method comprises: selecting a first geometry defining a volume-of-interest and selecting a magnetic field query, which is defined on a plurality of coordinates within the first geometry, the magnetic field query being monotonic. The method further comprises selecting a second geometry defining the magnetic structure and calculating a remanence distribution within the second geometry, by using the first geometry, the second geometry and the magnetic field query.

The invention discloses a permanent magnet device for magnetic resonance analysis. The permanent magnet device comprises a yoke, magnet pole plates, guide iron and shimming coil plates; one pair of symmetrical magnet pole plates are fixed to the yoke; the yoke encloses a closed magnet loop, and the magnet pole plates are located in the magnet loop; the shimming coil plates are fixed on the magnet pole plates through the guide iron; heating resistors are fixed onto the yoke; the heating resistors are connected with a constant temperature control power source; and the magnet pole plates are provided with temperature sensors; the permanent magnet device further comprises a PID constant temperature control system for regulating the current of the heating resistors to control the uniformity of a magnetic field; the temperature sensors are connected with the PID constant temperature control system; the shimming coil plates, a shimming power source group and an automatic shimming adjustment system are connected with the PID constant temperature control system; and the PID constant temperature control system adjusts the operating current of the heating resistors according to the compensation current of the shimming coil plates. With the permanent magnet device for magnetic resonance analysis provided by the invention adopted, the problem of deterioration of the stability of the magnetic field caused by magnet temperature variation which is further caused by heat emission increase of coils can be solved.

Embodiments relate to tire characterization systems and methods for combining direct tire pressure monitoring systems (TPMS) and tire resonance analysis in indirect tire pressure monitoring systems (TPMS) for the extraction of tire characteristics to characterize other tire parameters. In embodiments, iTPMS and methods that utilize anti-lock braking system (ABS) sensed signals coupled to an electronic control unit (ECU) that may comprise circuitry and/or controllers to process the sensed signals using a resonance frequency analysis (RFA) technique can be combined with direct tire pressure sensor measurements from direct TPMS systems. Because direct TPMS systems deliver a precise value of a tire characteristic (for example, tire pressure), one of the unknown parameters that influence the resonance effects can be removed. As a results, the detected resonance can be used to characterize another tire parameter that would not be accessible without knowledge of the precise value of the tire characteristic delivered by the direct TPMS system.

A device for ex situ magnetic resonance analysis is disclosed. The device comprises a static magnetic field unit (12) for generating a generally cylindrically symmetric static magnetic field outside the static magnetic field unit, and a radiofrequency unit (14) for generating a generally cylindrically symmetric radiofrequency field outside the radiofrequency unit. The radiofrequency field is perpendicular to the static magnetic field. A spatial inhomogeneity of the magnetic field substantially matches a spatial inhomogeneity of the radiofrequency field.

The invention relates to a carrier-based helicopter ship surface resonance modeling method, and belongs to the technical field of helicopter theoretical modeling. The method includes the steps that a single undercarriage load balance analysis model and a motion analysis model of a helicopter body on the ship surface are built; when a ship is guided to be brought down, modeling analysis is conducted on a bring-down device, the kinetic characteristic of the bring-down device is analyzed, and a sub system model is provided for overall ship surface resonance modeling analysis; according to the Newton's law of motion or the d'alembert's principle, a helicopter ship surface resonance analysis model for describing the ship surface motion and ship motion influences of a whole helicopter is built. According to the method, the built carrier-based helicopter ship surface resonance model can be applied to carrier-based helicopter ship surface resonance simulation analysis, and effective measures can be provided on the aspect of design to avoid and eliminate ship surface resonance.

A sample holder for use with magic angle spinning NMR and similar magnetic resonance analysis techniques which includes a sample holder sealed by an O-ring and a contact seal. The O-ring seals the sample volume during pressurization whereas the contact seal is active during analysis. The O-ring and the contact seal are disposed so that rotation of a plug selective engages one or both of the seals.

A method of magnetic resonance analysis of a body having therein at least one molecular species and water is disclosed. The method comprises, subtracting magnetic resonance signals induced by a second radiofrequency pulse sequence from magnetic resonance signals induced by a first radiofrequency pulse sequence followed by a evolution period. The first radiofrequency pulse sequence is selected so as to suppress magnetization for the water while preserving a generally longitudinal magnetization to the at least one molecular species. The second radiofrequency pulse sequence being selected so as to suppress transverse and longitudinal magnetization for both the water and the at least one molecular species.

A magnetic resonance method is disclosed. The method comprises applying to the sample a plurality of pairs of bipolar gradient pulse subsequences, acquiring a magnetic resonance signal from the sample, analyzing the signal, and issuing a report regarding the analysis.

The invention relates to the technical field of fault positioning, and discloses a cable water branch fault positioning method based on an impedance spectroscopy technology. The method comprises the steps of deriving a cable distribution parameter frequency change effect broadband impedance calculation model based on a transmission line theory; calculating cable line impedance by using the broadband impedance calculation model, and forming a cable broadband impedance spectrum; utilizing an algorithm to optimize a difference value function of an impedance spectrum calculation value and a measurement value to obtain defect section characteristic parameters; utilizing a linear resonance analysis method to analyze the defect section characteristic parameters so as to determine characteristic information of a defect section cable; analyzing the characteristic information of the defect section cable to diagnose the running state of the cable, detecting the change condition of the running state of the cable, and determining the water branch fault position of the cable. Compared with the prior art, the impedance calculation model is deduced through the transmission line theory, local defect characteristic parameters are extracted from impedance spectrum data, and accurate positioning and state evaluation of cable aging, damage and other defects are achieved.