54 results about "Signal velocity" patented technology

An apparatus and method of detecting COPD and in particular, emphysema utilizes a change in acoustic transmission characteristics of a lung due to e.g. the appearance of fenestrae (perforations) in the alveoli of the lung. The use of acoustic signals may provide good sensitivity to the existence of alveolar fenestrae, even for microscopic emphysema, and the appearance and increase in fenestrae may be determined by monitoring acoustic transmission characteristics such as, for example, an increase in acoustic signal velocity and velocity dispersion, and / or a change in attenuation. A transmitter may be located in e.g. the supra-clavicular space and receivers may be mounted on the chest. Measurements may be correlated between pairs of receivers to determine acoustic transmission profiles.

An ultrasonic fluid level sensor for use in a fluid container, preferably a vehicle fuel tank. The fluid level sensor generally includes a single transceiver having measurement and reference sections, an impedance layer and a housing having a reference element and an aperture. The measurement and reference sections are independent ultrasonic transceivers that are disk-shaped and ring-shaped, respectively, and are generally concentric. The reference element is a ring-shaped portion of the housing that is axially spaced from the reference section at a known distance, and the aperture is a disk-shaped opening in the housing that is axially spaced from the measurement section. In operation, the sensor is able to provide signals to an electronic controller that enable the controller to determine a signal velocity calibrated measurement of the fluid level that is compensated for temperature, fluid composition, and other velocity affecting factors.

Cross-well electromagnetic (EM) imaging is performed using high-power pulsed magnetic field sources, time-domain signal acquisition, low-noise magnetic field sensors, spatial oversampling and super-resolution image enhancement and injected contrast fluids. The contrast fluids increase the electromagnetic character of the formation and fluids, either the magnetic permeability or the dielectric permittivity. The acquired signals are processed and inter-well images are generated mapping electromagnetic (EM) signal speed (group velocity) rather than conductivity maps. EM velocity maps with improved resolution for both native and injected fluids are provided.

The present invention provides a frequency offset monitoring device and an optical coherent receiver. A low speed frequency offset monitoring device comprises a signal speed lowering section, for lowering the speed of an inputted signal and outputting the speed lowered signal, and a frequency offset monitor, for monitoring frequency offset of the speed lowered signal outputted by the signal speed lowering section.

An optical modulator for fiberoptic telecommunications is disclosed in which the optical signal velocity in the modulator waveguide and the electrical signal velocity in the traveling wave signal electrode are purposely mismatched by a factor of up to about 4. On-chip integrated inductors and capacitors are implemented to achieve the velocity mismatch. Improved electro-optic characteristics, such as return loss and sharper cut-off bandwidth are obtained.

Cross-well electromagnetic (EM) imaging is performed using high-power pulsed magnetic field sources, time-domain signal acquisition, low-noise magnetic field sensors, spatial oversampling and super-resolution image enhancement and injected magnetic nanofluids. Inter-well images are generated mapping electromagnetic (EM) signal speed (group velocity) rather than conductivity maps. EM velocity maps with improved resolution for both native and injected fluids are provided.

A DC brushless fan motor driving circuit has a Hall PWM signal generator, a speed signal generator, a PWM driver and a full-bridge switching circuit. The Hall PWM signal generator obtains a Hall sine wave signal from an external Hall sensor and converts the Hall sine wave signal to a varied Hall PWM signal. The speed signal generator is connected to an external PWM input signal to set speed of a fan motor and a low speed voltage to determine a present speed setting signal. The speed signal generator further obtains the varied Hall PWM signal to compare the present speed setting signal to generate a SPWM signal to the PWM driver. The PWM driver outputs a SPWM signal to the full-bridge switching circuit and then coil current is formed close to a sine wave signal to decrease the electromagnetic noise.

An antenna control system in which various antenna elements in a vertical row are coupled by fixed transmission lines to a central feeding point for a common signal. Adjustment of the phase of the common signal is achieved by means of a linearly movable slide having dielectric body portions influencing the signal velocity along said fixed transmission lines. Further, an electrical motor is used for linearly displacing said movable slide with said dielectric body portions.

The present invention provides a frequency offset monitoring device and an optical coherent receiver. A low speed frequency offset monitoring device comprises a signal speed lowering section, for lowering the speed of an inputted signal and outputting the speed lowered signal, and a frequency offset monitor, for monitoring frequency offset of the speed lowered signal outputted by the signal speed lowering section.

A layout configuration of a differential pair for a printed circuit board (PCB) having a signal plane is provided. In a preferred embodiment, the layout configuration comprises: a differential pair on the signal plane; a pair of vias abutting the differential pair, and the pair of vias being mutually dissymmetrical about the differential pair; and a distance between the pair of vias along the differential pair being equal to ½ TV, wherein T is a signal rise time, V is a speed of the signal. Therefore, the layout configuration can meet with the requirements of impedance matching, reduce reflection, and improve signal integrity.

A system is disclosed for position registration and phase synchronization of monitors in a monitor network. Each monitor includes a transceiver having a transponder circuit with a calibrated transponder delay. To measure a distance between monitors, an oscillator at a first monitor generates a measurement signal which is transponded by a second monitor for receipt by the first monitor. A phase difference between the received signal and the first monitor oscillator is determined and used with the signal velocity and transponder delay to calculate the distance between monitors. The measured distances are combined with other data (e.g. monitor elevations) to calculate monitor locations. A phase delay is then measured by transmitting a signal from the first to the second monitor for comparison with the second monitor oscillator. A phase difference between oscillators (for use in synchronizing the monitors) is then calculated using the phase delay, separation distance and signal velocity.

The invention relates to a method for positioning non-cooperative target in passive positioning system based on cell mobile base station. The method mainly includes: at least four signal intercepting devices are arranged in the coverage area of cell mobile base station signal, direct signal of base station and reflected signal of a target to the base station are received, time difference of the direct signal and the reflected signal which reach each intercepting device is determined, and the position of the target is finally determined according to the position of each intercepting device, the position of cell base station and signal velocity. The invention has the advantages that input value of formula for calculating the position of target is simple, positioning accuracy is high, and real-time performance is good. The method of the invention also can be applied to other similar positioning problems conveniently.

Cross-well electromagnetic (EM) imaging is performed using high-power pulsed magnetic field sources, time-domain signal acquisition, low-noise magnetic field sensors, spatial oversampling and super-resolution image enhancement and injected magnetic nanofluids. Inter-well images are generated mapping electromagnetic (EM) signal speed (group velocity) rather than conductivity maps. EM velocity maps with improved resolution for both native and injected fluids are provided.

A transmission apparatus for multiplexing optical signals has a multi-rate signal processing unit that has a plurality of signal processing circuits in advance according to various signal speeds and frame formats and selects a necessary signal processing circuit as necessary. In addition, the transmission apparatus acquires a type code, used to identify the type of the signal of a removable optical module, from the optical module and, from the acquired information, automatically determines the operation mode of the multi-rate signal processing unit, bandwidth allocations according to the signal speeds, and monitoring item contents for different frame formats to eliminate the need for maintenance engineer's work that is otherwise required when a low-speed signal is added.

Disclosed herein are an apparatus and a method for measuring velocity of an ultrasound signal. The apparatus for measuring velocity of an ultrasound signal according to an exemplary embodiment of the present invention includes a transmitting module transmitting ultrasound signals to targets; a receiving module receiving the ultrasound signals reflected from the targets; an image generating module using the received ultrasound signals to generate a plurality of ultrasonic images having different sound velocities; and a sound velocity determining module using the plurality of generated ultrasonic images to determine optimal sound velocity for scanning the targets.

An antenna control system in which various antenna elements in a vertical row are coupled by fixed transmission lines to a central feeding point for a common signal. Adjustment of the phase of the common signal is achieved by means of a linearly movable slide having dielectric body portions influencing the signal velocity along said fixed transmission lines. Further, an electrical motor is used for linearly displacing said movable slide with said dielectric body portions.

An optical modulator for fiberoptic telecommunications is disclosed in which the optical signal velocity in the modulator waveguide and the electrical signal velocity in the traveling wave signal electrode are purposely mismatched by a factor of up to about 4. On-chip integrated inductors and capacitors are implemented to achieve the velocity mismatch. Improved electro-optic characteristics, such as return loss and sharper cut-off bandwidth are obtained.

A traffic radar captures the patrol vehicle return signal by saving the patrol return when the radar system is placed in a standby state. If the radar is in standby for more than a predetermined period of time before reentering a transmitting mode, the system searches for a new patrol signal within a speed window around the saved patrol signal speed. If the radar is in standby for less than the predetermined period of time, the system initially searches for a new patrol signal over a range that excludes an interval around the saved patrol signal speed. If the new patrol signal is not found, then in a subsequent search the interval is included in the searched spectrum.

The invention relates to a quick-response stepping motor pole speed drive system and method. A stepping motor is connected to an incremental encoder through a synchronous rotation mechanism, and the incremental encoder is connected with a controller. When the stepping motor rotates one step angle, the incremental encoder feeds back one or more signals to the controller correspondingly, and the controller takes the feedback signal as a signal that the stepping motor rotates a next step angle. Because the encoder is high in speed of feeding back the signal, the motor nearly can receive feedback signals of a plurality of encoders at the same time after the motor rotates one step angle, thereby driving the next step angle. The method can enable the stepping motor not to lose a step during high-frequency operation, greatly reduces the transmission error of the industrial control field, improves the utilization rate of the stepping motor, guarantees the control precision, enlarges the control range of the rotating speed of the motor, is quick in response speed, facilitates the precise positioning, can be widely used in the numerical control machining, and effectively improves the machining precision.

A transmission apparatus for multiplexing optical signals has a multi-rate signal processing unit that has a plurality of signal processing circuits in advance according to various signal speeds and frame formats and selects a necessary signal processing circuit as necessary. In addition, the transmission apparatus acquires a type code, used to identify the type of the signal of a removable optical module, from the optical module and, from the acquired information, automatically determines the operation mode of the multi-rate signal processing unit, bandwidth allocations according to the signal speeds, and monitoring item contents for different frame formats to eliminate the need for maintenance engineer's work that is otherwise required when a low-speed signal is added.

A traffic radar captures the patrol vehicle return signal by saving the patrol return when the radar system is placed in a standby state. If the radar is in standby for more than a predetermined period of time before reentering a transmitting mode, the system searches for a new patrol signal within a speed window around the saved patrol signal speed. If the radar is in standby for less than the predetermined period of time, the system initially searches for a new patrol signal over a range that excludes an interval around the saved patrol signal speed. If the new patrol signal is not found, then in a subsequent search the interval is included in the searched spectrum.

An automatic method for categorizing heartbeats using two or more selected ECG signals, the method comprising, when a heartbeat has been detected, the steps of: (a) determining a signal velocity for each selected signal at a categorization fiducial time tC within the detected heartbeat; (b) forming a vector F(tC) having as its components the velocities of each of the selected signals at time tC; (c) determining the angle between the vector F(tC) and a previously-stored template vector; (d) comparing the angle with a threshold angle; and (e) if the angle is less than the threshold angle, categorizing the heartbeat as similar to a heartbeat which corresponds to the template vector.

The invention relates to an ultrasonic flow instrument circuit system for preventing miswave interference. The ultrasonic flow instrument circuit system comprises a singlechip module, a voltage comparing module, a signal shielding module, a water inlet end ultrasonic transducer and a water outlet end ultrasonic transducer, wherein the singlechip module controls the voltage comparing module, the signal shielding module, the water inlet end ultrasonic transducer and the water outlet end ultrasonic transducer. According to a control method, the first time measurement is used for locating a position of an ultrasonic signal and completely shielding interference signals before the ultrasonic signal occurs, and the second time measurement is used for accurately measuring the flying time of the ultrasonic signal and solving the time difference of the ultrasonic signal. The ultrasonic flow instrument circuit system has the effects that by using the principle that the ultrasonic signal velocity in a water direction is higher and the flying time is shorter and adopting a method for measuring the ultrasonic flying time in two steps, the time different of an ultrasonic flow instrument signal can be accurately measured, miswave interference is avoided, and the accuracy and the stability of an ultrasonic flow instrument are improved.

The invention discloses an eight-bit full-light comparator based on a quantum dot semiconductor optical amplifier. The eight-bit full-light comparator comprises a logic Not gate composed of a Mach-Zehnder interferometer and a logic XOR gate composed of eight Mach-Zehnder interferometers, wherein the output of the former Mach-Zehnder interferometer is delayed to be used as a control signal of the next Mach-Zehnder interferometer, the control signal and a signal to be compared are input to the next Mach-Zehnder interferometer so as to be subjected to logic operation to obtain the cascade connection of an XOR comparative result, and the quantum dot semiconductor optical amplifier is used as a nonlinear element in the logic Not gate and the logic XOR gate. The signal processing speed of the full-light comparator can be up to 500Gb / s. The eight-bit full-light comparator is applied to high-speed signal processing so as to be suitable for the development of full-light networks.

The invention relates to an arrangement for measuring the speed of sound, the arrangement comprising: an electrical pulse generating means (402) for generating an output electrical pulse signal (404), a transmitting transducer (403) for converting said output electrical pulse signal (404) into an output acoustic pulse signal (405), a reflector (407) for reflecting said output acoustic pulse signal (405), thereby producing a reflected acoustic pulse signal (409), a receiving transducer (408) being arranged such as to receive said output acoustic pulse signal (405) transmitted directly from said transmitting transducer and said reflected acoustic pulse signal (409) reflected by said reflector, wherein said receiving transducer converts the received output acoustic pulse signal (405) into a reconstructed output electrical pulse signal (410) and the reflected acoustic pulse signal (409) into a reconstructed reflected electrical pulse signal (411), a speed determination means for determining the speed of sound (412) using the reconstructed output electrical pulse signal (410) and the reconstructed pulse signal (411).

A sub signal modulation apparatus, with the intention of stabilized transmission of a sub signal superimposed on main signal light irrespective of the intensity of the main signal light when used in a general-purpose main signal transmitter, including a sub signal outputting unit; a variable optical attenuator for variably attenuating main signal light, into which the main signal has been modulated, at a response speed lower than ½ of a speed of the main signal; an attenuation determining unit for determining, in accordance with the sub signal output from the sub signal outputting unit, an attenuation of the variable optical attenuator for the main signal light; and a stabilizing controller for controlling the attenuation determining unit such that an amplitude of the attenuation of the variable optical attenuator is stabilized to have a constant ratio to a mean intensity of the main signal light.

The invention discloses a frequency stepping signal speed compensation system based on difference frequency double waveforms. The frequency stepping signal speed compensation system comprises a difference frequency dual-waveband signal generating unit (2), a broadband antenna feed system (3), a difference frequency dual-waveband signal receiving unit (4), a frequency source (5) and a signal processor (6); the difference frequency dual-waveband signal generating unit (2) transmits a difference frequency dual-waveband signal; the difference frequency dual-waveband signal receiving unit (4) receives an echo signal; the signal processor (6) implements speed compensation. The frequency stepping signal speed compensation system disclosed by the invention can solve the problem of poor engineeringrealizability of the conventional stepping frequency signal speed measurement method, is realized through hardware design and is less in condition constrain, strong in engineering realizability and high in compensation precision.

To obtain ambient sound velocity of a subject with high accuracy in a ultrasonic diagnosis apparatus. In an ambient sound velocity obtaining method that transmits ultrasonic waves from an ultrasonic probe, receives reflected waves reflected by a subject to obtain received signals, performs a receive focusing process on the received signals using receive delay times based on a plurality of sound velocity settings to obtain in-phase sum signals with respect to each sound velocity setting, and obtains an ambient sound velocity of the subject based on the in-phase sum signals with respect to each sound velocity setting, the in-phase sum signals with respect to each sound velocity setting is separated into an in-phase sum signal corresponding to a boundary portion in the subject and an in-phase sum signal corresponding to portions other than the boundary portion, an index is obtained based on at least either one of the in-phase sum signals, and the ambient sound velocity is obtained based on the index.